1 

USDA United States 

z.==;;;; Department _ of Agriculture 

Forest Service 

Rocky Mountain 

Research Station 

Proceedings 

RMRS-P-9 

June 1999 

Proceedings: Ecology 

and Management 

of Pinyon-Juniper 

Communities Within 

the Interior West 

RMRS-FILE COpy 

Sustaining and Restoring a Diverse Ecosystem 

This file was created by scanning the printed publication.

Errors identified by the software have been corrected;

however, some errors may remain.
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I 

Abstract ----------------------------------------------------------------- Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: ecology and management of pinyon-juniper 

communities within the Interior West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research Station. 411 p. 

A symposium held September 15-18,1997, in Provo, UT, and Sanpete County, UT, provided information on the 

ecology, management, resource values, and restoration of pinyon-juniper communities in the Interior Western 

United States. The conference was hosted by the USDA Forest Service, Rocky Mountain Research Station and 

the Utah Division of Wildlife Resources in cooperation with personnel from other agencies and organizations. Oral 

and poster presentations were given by scientists, land managers, and educators. Also included was a field tour 

to observe distribution and areas of occurrence of various woodland types. Mechanical chaining and seeding 

demonstrations exhibited operational procedures, removal of competition, and creation of multiple seedbeds. 

Comparisons of older treatments where introduced species were planted were made with more recent restoration 

plantings designed to restore native understory herbs and shrubs. The field tour also emphasized identification and 

characterization of successional or transition stages resulting in thresholds in vegetative composition that influence 

management practices. 

This conference focused on four topics. First was identifying the principal pinyon-juniper community associations, 

defining areas of distribution, and characterizing climatic, biotic, edaphic, and human influences upon community 

structure. Second were several discussions of resources associated with pinyon-juniper communities. Topic three 

focused on methodologies a.nd practices available to restore disturbed pinyon-juniper woodlands to natural 

assemblages of native species. The fourth topic examined the implications of management practices upon 

community distribution, species composition, and presence of introduced species. Management to sustain diverse 

. pinyon-juniper communities is an important issue. In addition, management of disturbed sites is equally important 

as weeds continue to invade and spread, fire frequency and damages are increasing, and continued alteration of 

plant communities limits management options. 

Keywords: restoration, range resources, succession, cheatgrass, native seed, watershed, wildlife, soil 

Sponsors and Cooperators 

USDA Forest Service, Rocky Mountain Research Station 

Utah Division of Wildlife Resources 

USDA Agricultural Research Service 

USDA Forest Service, Intermountain Region 

Department Botany and Range Science, Brigham Young University 

Division of Continuing Education, Brigham Young University 

Utah State University 

Rocky Mountain Research Station 

324 25th Street 

Ogden, UT 84401 
Proceedings: Ecology and Management of 

Pinyon-Juniper Communities Within the 

Interior West 

September 15-18, 1997 

Brigham Young University 

Conference Center 

Provo, Utah 

Compilers: 

Stephen B. Monsen 

USDA Forest Service 

Rocky Mountain Research Station 

Shrub Sciences Laboratory 

735 North 500 East 

Provo, UT 84606 

Richard Stevens (Retired) 

Utah Division of Wildlife Resources 

Great Basin Research Area 

540 North Main 

Ephraim, UT 84627 

Technical Coordinators 

Dwight Bunnel 

Utah Division of Wildlife Resources 

1597 West North Temple 

Salt Lake City, UT 84114-6301 

Sherel Goodrich 

USDA Forest Service 

Ashley National Forest 

355 North Vernal Avenue 

Vernal, UT 84978 

Kimball T. Harper (Retired) 

Department of Botany and Range Science 

Brigham Young University 

Provo, UT 84602 

Rick Miller 

USDA Agricultural Research Service 

HD 714.15 HWY 205 

Burns, OR 97720 

Robin J. Tausch 

USDA Forest Service 

Rocky Mountain Research Station 

University of Nevada 

920 Valley Road 

Reno, NV 89512 

Robert Thompson 

USDA Forest Service 

Manti-La Sal National Forest 

599 West Price River Drive 

Price, UT 84501 

Sustaining and Restoring a Diverse Ecosystem 

RMRS-FILE COpy 

Contents 

Page 

Introduction .......................................................................................................................................................... 1 

Stephen B. Monsen 

Richard Stevens 

Symposium on Pinyon and Juniper Ecology, Restoration, and 

Management: Introduction .............................................................................................. 3 

Ecology .................................................................................................................................................................. 5 

W. A. Laycock 

Robin J. Tausch 

Neil E. West 

George E. Gruell 

Jeanne C. Chambers 

Eugene W. Schupp 

Stephen B. Vander Wall 

Robert S. Nowak 

Darrin J. Moore 

Robin J. Tausch 

James A. Young 

T. J. Svejcar 

Kimball T. Harper 

James N. Davis 

Ecology and Management of Pinyon-Juniper Communities Within 

the Interior West: Overview of the "Ecological Session" of the Symposium ................... 7 

Historic Pinyon and Juniper Woodland Development ................................................... 12 

Distribution, Composition, and Classification of Current Juniper-Pinyon 

Woodlands and Savannas Across Western North America .......................................... 20 

Historical and Modern Roles of Fire in Pinyon-Juniper ................................................. 24 

Seed Dispersal and Seedling Establishment of Pinon and Juniper 

Species within the Pinon-Juniper Woodland ................................................................. 29 

Ecophysiological Patterns of Pinyon and Juniper ......................................................... 35 

Harvesting Energy from 19th Century Great Basin Woodlands .................................... 47 

Biotic, Edaphic, and Other Factors Influencing Pinyon-Juniper 

Distribution in the Great Basin ...................................................................................... 51 

Renee A. O'Brien Description of Pinyon-Juniper and Juniper Woodlands in Utah and 

Sharon W. Woudenberg "Nevada From an Inventory Perspective ........................................................................ 55 

Robert M. Thompson 

Simon A. Lei 

Sherel Goodrich 

Natalie Gale 

Darren Naillon 

Kelly Memmott 

Stephen B. Monsen 

Stephen C. Bunting 

James L. Kingery 

Eva Strand 

Steven K. Rust 

An Example of Pinyon-Juniper Woodland Classification in Southeastern Utah ........... 60 

Gradient Analysis of Pinyon-Juniper Woodland in a Southern Nevada 

Mountain Range ............................................................................................................ 64 

Cheatgrass Frequency at Two Relic Sites Within the Pinyon-Juniper 

Belt of Red Canyon ....................................................................................................... 69 

A Comparison of Understory Species at Three Densities in a 

Pinyon-Juniper Woodland ............................................................................................. 72 

Effects of Succession on Species Richness of the Western Juniper 

Woodland/Sagebrush Steppe Mosaic ........................................................................... 76 

Pinyon-Juniper Woodland Classification and Description in Research 

Natural Areas of Southeastern Idaho ............................................................................ 82 
Simon A. Lei 

Simon A. Lei 

Chad S. Horman 

Val Jo Anderson 

N. J. Brian 

P. G. Rowlands 

D. A. Jameson 

Allen Huber 

Sherel Goodrich 

Kim Anderson 

D. J. Weber 

E. D. Bunderson 

J. N. Davis 

D. L. Nelson 

A. Hreha 

Jeffrey A. Creque 

Neil E. West 

James P. Dobrowolski 

Angela R. Jones 

Bruce N. Smith 

Lee D. Hansen 

Stephen B. Monsen 

Richard Stevens 

Dennis D. Austin 

Clare L. Poulsen 

Scott C. Walker 

Richard Stevens 

John E. Mitchell 

Thomas C. Roberts, Jr. 

Tree Size and Ring Width of Three Conifers in Southern Nevada ............................... 94 

Host-Parasite Relationship Between Utah Juniper and Juniper Mistletoe 

in the Spring Mountains of Southern Nevada ............................................................... 99 

Utah Juniper Herbaceous Understory Distribution Patterns in Response 

to Tree Canopy and Litter Removal ............................................................................ 105 

Resurvey of the Vegetation and Soils of Fishtail Mesa: A Relict 

Area in Grand Canyon National Park, Arizona ........................................................... 113 

Diversity with Successional Status in the Pinyon-Juniper/Mountain 

Mahogany/Bluebunch Wheatgrass Community Type Near 

Dutch John, Utah ........................................................................................................ 114 

Diseases and Environmental Factors of the Pinyon-Juniper 

Communities ............................................................................................................... 118 

Methods in Historical Ecology: A Case Study of Tintic Valley, Utah ........................... 121 

Calorimetric Study of the Effects of Water and Temperature on the 

Respiration and Growth of Small Burnet and Alfalfa ................................................... 134 

Changes in Plant Composition within a Pinyon-Juniper Woodland ............................ 138 

Soil Seed Banking in Pinyon-Juniper Areas With Differing Levels 

o! Tree Cover, Understory Density and Composition ................................................. 141 

Distribution of Pinyon-Juniper in the Western United States ...................................... 146 

Resource Values ............................................................................................................................................ 155 

James E. Bowns 

Sherel Goodrich 

Bruce A. Roundy 

Jason L. Vernon 

James P. Dobrowolski 

Francis J. McCarthy III 

James P. Dobrowolski 

Ecology and Management of Pinyon-Juniper Communities Within 

the Interior West: Overview of the "Resource Values Session" 

of the Symposium ....................................................................................................... 157 

Multiple Use Management Based on Diversity of Capabilities and 

Values Within Pinyon-Juniper Woodlands .................................................................. 164 

Watershed Values and Conditions Associated with Pinyon-Juniper 

Communities ............................................................................................................... 172 

Watershed-Scale Research in a Juniper Ecosystem .................................................. 188 

Hydrogeology and Spring Occurrence of a Disturbed Juniper 

Woodland in Rush Valley, Utah .................................................................................. 194 
Theresa M. Lowe 

James P. Dobrowolski 

Charles L. Greenwood 

Sherel Goodrich 

John A. Lytle 

Mitchell J. Willis 

Richard F. Miller 

William H. Kruse 

Craig G. White 

Jerran T. Flinders 

Rex G. Cates 

Boyde H. Blackwell 

H. Duane Smith 

Michael L. Morrison 

Linnea S. Hall 

Michelle L. Commons 

Richard K. Baydack 

Clait E. Braun 

Kathleen M. Paulin 

Jeffrey J. Cook 

Sarah R. Dewey 

Merrill Webb 

Joel C. Janetski 

Peter F. Ffolliott 

Gerald J. Gottfried 

William H. Kruse 

Sherel Goodrich 

Lori Armstrong 

Robert Thompson 

Erosion and Deposition in a Juniper Woodland: The Chicken or the Egg? ................ 200 

Response of Bighorn Sheep to Pinyon-Juniper Burning Along 

the Green River Corridor, Dagget County, Utah ......................................................... 205 

Importance of Western Juniper Communities to Small Mammals ............................. 210 

Commercial Fuelwood Harvesting Affects on Small Mammal 

Habitats in Central Arizona ......................................................................................... 215 

Dietary Use of Utah Juniper Berries by Gray Fox in Eastern Utah ............................. 219 

Habitat Relationships of Amphibians and Reptiles in the Inyo-White 

Mountains, California and Nevada .............................................................................. 233 

Sage Grouse Response to Pinyon-Juniper Management ........................................... 238 

Pinyon-Juniper Woodlands as Sources of Avian Diversity ......................................... 240 

Importance of Pinyon-Juniper Habitat to Birds ........................................................... 244 

Role of Pinyon-Juniper Woodlands in Aboriginal Societies of the 

Desert West ................................................................................................................ 249 

Past, Present, and Potential Utilization of Pinyon-Juniper Species ............................ 254 

Endemic and Endangered Plants of Pinyon-Juniper Communities ............................ 260 

Ecological Restoration ................................................................................................................................ 269 

Robert B. Campbell, Jr. Ecology and Management of Pinyon-Juniper Communities Within 

the Interior West: Overview of the "Ecological Restoration" Session 

of the Symposium ....................................................................................................... 271 

John A. Fairchild Pinyon-Juniper Chaining Design Guidelines For Big Game Winter 

Range Enhancement Projects .................................................................................... 278 

Richard Stevens Mechanical Chaining and Seeding ............................................................................. 281 

Richard Stevens Restoration of Native Communities by Chaining and Seeding ................................... 285 
James H. Chadwick 

Deanna R. Nelson 

Carol R. Nunn 

Debra A. Tatman 

Douglas Sorensen 

Brian F. Jacobs 

Richard G. Gatewood 

M. E. Farmer 

K. T. Harper 

J. N. Davis 

Vicente L. Lopes 

Peter F. Ffolliott 

Malchus B. Baker, Jr. 

Harry Barber 

Paul Chapman 

Sid Goodloe 

Samuel R. Loftin 

Ivan Erskine 

Sherel Goodrich 

Sherel Goodrich 

Chad Reid 

Mike Pellant 

Julie Kaltenecker 

Steven Jirik 

E. Durant McArthur 

Stanford A. Young 

Scott C. Walker 

Mark Majerus 

Susan Winslow 

Joe Scianna 

Melissa V. Britton 

Val Jo Anderson 

R. D. Horrocks 

Howard Horton 

Sherel Goodrich 

Allen Huber 

Thinning Versus Chaining: Which Costs More? ......................................................... 290 

Advantages and Effectiveness of Rollerchopping ....................................................... 293 

Restoration Studies in Degraded Pinyon-Juniper Woodlands of 

North-Central New Mexico .......................................................................................... 294 

The Influence of Anchor-Chaining on Watershed Health in a 

Juniper-Pinyon Woorland in Central Utah ................................................................... 299 

Impacts -of Vegetative Manipulations on Sediment Concentrations 

from Pinyon-Juniper Woodlands ................................................................................. 302 

The Panguitch Wildlife Habitat Improvement Project .................................................. 306 

Watershed Restoration Through Integrated Resource Management on 

Public and Private Rangelands ................................................................................... 307 

Initial Response of Soil and Understory Vegetation to a Simulated 

Fuelwood Cut of a Pinyon-Juniper Woodland in the Santa Fe National Forest .......... 311 

Applying Fire to Pinyon-Juniper Communities of the Green River 

Corridor, Daggett County, Utah .................................................................................. 315 

Soil and Watershed Implications of Ground Cover at Burned and 

Unburned Pinyon-Juniper Sites at Rifle Canyon and Jarvies Canyon ........................ 317 

Use of OUST® Herbicide to Control Cheatgrass in the Northern 

Great Basin ................................................................................................................. 322 

Development of Native Seed Supplies to Support Restoration of 

Pinyon-Juniper Sites ................................................................................................... 327 

Species Compatibility and Successional Processes Affecting Seeding 

of Pinyon-Juniper Types ............................................................................................. 331 

Native Plant Solutions for Conservation Problems ..................................................... 338 

Evaluation of Plant Materials for Use in Reclamation of Disturbed 

Rangelands in Semi-Arid Areas of Northern Utah ...................................................... 339 

Response of a Seed Mix and Development of Ground Cover on 

Northerly and Southerly Exposures in the 1985 Jarvies Canyon Burn, 

Daggett County, Utah ................................................................................................. 346 
Richard Stevens 

Scott C. Walker 

Stuart Wooley 

Regrowth of 'Ladak' Alfalfa on Pinyon-Juniper Rangelands Following 

Various Timing and Types of Spring Use ................................................................... 352 

Management Implications .......................................................................................................................... 355 

Mike Pellant 

Robin J. Tausch 

Lee E. Eddleman 

Deanna R. Nelson 

John A. Fairchild 

Carol R. Nunn-Hatfield 

Rick Miller 

Robin Tausch 

Wendy Waichler 

Rick Miller 

Tony Svejcar 

Jeff Rose 

Sherel Goodrich 

Brian Barber 

Tony Svejcar 

Tom J. Eager 

Thomas C. Roberts, Jr. 

Sherel Goodrich 

Dustin Rooks 

G. Allen Rasmussen 

Robin Tausch 

Steve A. Bunting 

Linda MacDonald 

Ecology and Management of Pinyon-Juniper Communities Within 

the Interior West: Overview of the "Management Implications Session" 

of the Symposium ....................................................................................................... 357 

Transitions and Thresholds: Influences and Implications for 

Management in Pinyon and Juniper Woodlands ........................................................ 361 

Ecological Guidelines for Management and Restoration of Pinyon 

and Juniper Woodlands .............................................................................................. 366 

Political Guidelines for Management and Restoration of Pinyon 

and Juniper Woodlands .............................................................................................. 371 

Old-Growth Juniper and Pinyon Woodlands ............................................................... 375 

Conversion of Shrub Steppe to Juniper Woodland ..................................................... 385 

Return Interval for Pinyon-Juniper Following Fire in the Green River 

Corridor, Near Dutch John, Utah ................................................................................ 391 

Implications of Weedy Species in Management and Restoration of 

Pinyon and Juniper Woodlands .................................................................................. 394 

Factors Affecting the Health of Pinyon Pine Trees (Pinus edulis) in 

the Pinyon-Juniper Woodlands of Western Colorado ................................................. 397 

The Budgetary, Ecological, and Managerial Impacts of Pinyon-Juniper 

and Cheatgrass Fires .................................................................................................. 400 

Control of Weeds at a Pinyon-Juniper Site by Seeding Grasses ................................ 403 

Use of the Helitorch to Enhance Diversity on Riparian Corridors in 

Mature Pinyon-Juniper Communities: A Conceptual Approach .................................. 408 

Wildfire Rehabilitation in Utah ..................................................................................... 410 

Introduction 

Ecology 

Resource 

Values 

Ecological 

Restoration 

Management 

Implications 

Introduction 

Symposium on Pinyon and Juniper Ecology, 

Restoration, and Management: Introduction 

Stephen B. Monsen 

Richard Stevens 

Pinyon and juniper woodlands provide human, wildlife, 

soil, water, and other ecologically important resources. These 

woodlands are an integral part of the landscape of large 

geographical regions of the Interior Western United States. 

Conditions and diversity of this type are critical. Managing 

pinyon and juniper woodlands to sustain tree and understory associations becomes more practical as the ecology of 

this type is better understood. For example, knowing how to 

manipulate management practices could help in modifying 

successional changes on a landscape basis. 

To help reach the goal of increased knowledge, a 

multi agency-supported symposium brought Federal, State, 

and local government officials, university researchers, private companies, and private individuals together for 4 days 

in the autumnof1997 at Brigham Young University, Provo, 

UT. This resulting proceedings is a step toward accumulating knowledge, and perhaps will foster cooperation and 

partnerships among the large array of private and public 

entities interested in the vast Interior Western ecosystem. 

In this introduction we highlight some of the themes and 

critical issues that arose during the symposium, noting some 

of the management options. 

The Western Setting 

Within the Interior West, different species of pinyon and 

juniper occur wi th diverse shrubs and herbs forming distinct 

associations. The total area occupied by pinyon and juniper 

woodlands is not precisely mapped and described because 

various associations exist with different assembly of species, 

highly variable tree densities, and age classes, making the 

task of mapping difficult. In addition, climatic and biotic 

factors influence changes in plant composition, creating 

both expansion and decline of common woodlands. 

Recent studies have better defined the interaction between environment and vegetative changes in pinyon and 

juniper woodlands and non-tree species than have previously existed. For example, changes are evident in the paleoecological records, and multiple stages of plant succession 

have been identified and can be used to predict general 

changes in landscape ecology. More recent studies show us 

the influence of disturbances on the long-term patterns 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Stephen B. Monsen is Botanist, Rocky Mountain Research Station, Shrub 

Sciences Laboratory, 735 North 500 East, Provo, UT 84606. Richard Stevens 

was Project LeaderlResearch Biologist (retired), Division of Wildlife Resources, Great Basin Experiment Station, Ephraim, UT 84627. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

of change and the potential recovery of specific plant 

associations. 

Of particular concern is the presence and effect of thresholds on successional development of these woodlands. Although other plant communities may also express stages or 

thresholds as changes occur, once particular thresholds are 

reached within a pinyon and juniper woodland, subsequent 

changes are set and are not likely altered. Factors affecting 

these changes may include topography, soils, climate, history of use, fires, and tree presence. Influences operate over 

extended periods, affecting large regions and landscapes. 

Highly variable plant communities currently exist due to 

different stages of plant succession and to the recent expansion of both pinyon and juniper. 

Understanding the structure and composition of pinyon 

and juniper woodlands is essential in identifying thresholds 

and their influence on returning communities to earlier 

status through management or active restoration. Selection 

of sites for improvement can be based on a better understanding of the ecological status and potential for natural 

recovery. Woodlands that support a sufficient array of understory species and can recover by elimination of tree 

competition can be better defined and treated. Sites that 

may require seeding to restore understory herbs and shrubs 

or may be subject to weed invasion can also be better 

identified. 

Management Issues 

Many pinyon andjuniper communities within the West, like 

many other plant associations, have been subjected to intensive livestock grazing. This impact, along with recent changes 

in fire regimes and localized tree harvesting, has contributed to changes in tree presence, age structure, density, and 

particularly to the composition of understory species. Loss of 

habitat, diminished watershed conditions, and the recent 

increase of weeds have created serious management problems. In addition, increases in wildfire frequency caused by 

the presence of annual weeds, and increases in the frequency 

of devastating wildfires within overgrown stands of trees, 

are a more recent problem associated with disturbed woodland conditions. The decline and loss of understory species 

coupled with an increase in tree overstory ultimately results 

in a loss of species richness and likely conversion to a 

dominance of undesirable weeds. Recent appearance of more 

troublesome and persistent perennial weeds within pinyon 

and juniper communities creates additional need to retain 

native understory species. 

These issues have been a concern to land managers for a 

long time. Various interagency steering committees and 

organizations (including this symposium) have addressed 

3 
these and other issues. Ecology of pinyon and juniper communities was the first topic addressed in this conference. 

Although considerable information is lacking, a much better 

understanding of the distribution, community composition, 

and patterns of change, particularly of disturbed woodlands, 

is now available. Descriptions of stages and patterns of 

community degradation are better identified and understood. Factors influencing annual weed invasion and resulting conversion of woodlands to annual grasslands coupled 

with increasing fire frequency is also much better documented. Areas and sites that have degraded with diminished amounts of understory species and are likely to revert 

to weeds can now be better identified and treated. 

Management Alternatives ___ _ 

Artificial restoration of pinyon and juniper woodlands has 

received considerable attention. Practices that included 

removal of existing trees to reduce competition have often 

been criticized as unnecessary, site destructive, and not 

ecologically sound. However, examination of existing information does not support these assumptions. Restoration or 

enhancement of any disturbed community including shrubland associations, upland herb communities, or weed-infested sites requires reduction of existing competition, creation of suitable seedbeds, and actual seeding. In most 

situations, elimination of competition is accomplished by 

mechanical tillage or application of selective herbicides. 

Plowing, dis king, or related tillage treatments are the most 

common means of mechanical treatment. These procedures 

reduce competition and aid in creation of required seedbeds. 

Such practices can seriously disturb soils and tend to eliminate most existing vegetation. 

Chaining and cabling practices were selectively tested 

and adapted to treat woodlands as minimal impacts occur to 

soils and understory species. Chaining has proven to be the 

most versatile practice available to selectively reduce trees, 

prepare diverse seedbeds, and facilitate planting mixtures 

of seed. Percent of trees remo,:,"ed and percent and depth of 

4 

soil surface that is tilled can be easily regulated by modifying 

operational procedures. Chaining coupled with aerial seeding of select species that require minimal seedbed preparation has proven universally successful within this communitytype. Including the use oftractor-mounted seed dribblers 

to plant seeds that benefit from being more deeply incorporated in the soil has provided the necessary method required 

to seed most species. These techniques provide the means to 

successfully restore most species native of the pinyon and 

juniper woodlands by seeding. 

Significant progress has been achieved in developing 

native seeds in sufficient amounts required to restore diverse communities. Seeds are now available from commercial companies are adapted ecotypes of many native species 

that can be used on a variety of sites. This has resulted in a 

slow but steady transition from rehabilitation plantings 

involving the use of introduced species to more complete 

restoration plantings using site-adapted native species. A 

much greater array of native species is currently available to 

restore pinyon and juniper communities than any other 

vegetative type that exists in the West. Ifproperly planned, 

restoration of native communities through artificial seedings 

can be achieved on large projects. Regulations are in place to 

assure native seed of site-adapted ecotypes and species are 

harvested, produced, and marketed. 

Older plantings in pinyon and juniper communities demonstrate that altering tree encroachment and restoration of 

diverse communities is attainable and can be ecologically 

maintained. Restoring communities to improve watershed 

stability, improve wildlife habitat, and prevent weed encroachment is feasible and ecologically attainable. Seeding 

introduced species, principally perennial grasses, to protect 

disturbances and prevent further site degradation can be 

successful, but can interfere with natural recovery processes. 

We hope future conferences and partnerships will continue our knowledge sharing, always keeping in mind that 

sustaining and restoring pinyon and juniper woodlands will 

play a major role in achieving and maintaining a diverse 

ecosystem in the Interior Western United States. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Ecology 

5 

Ecology and Management of Pinyon-Juniper 

Communities Within the Interior West: 

Overview of the "Ecological Session" of the 

Symposium 

w. A. Laycock 

Abstract-Categories of papers in the "Ecological Session" were 

history and ecological change, distribution, classification, ecology 

and physiology, succession and diversity, and disease. Substantial 

changes have taken place in pinyon-juniper woodlands over the 

past 150 years. Coinciding with and following early extensive 

localized harvesting, these woodlands have been dramatically expanding and thickening. Several authors predicted future large, 

severe fires. Ecological research reported included seed dispersal 

and banks, seedling establishment, and ecophysiological relations 

of pinyon and juniper. One model presented illustrated the process 

of increases in tree density and cover and corresponding decreases 

in understory. This model would explain most of the processes and 

results reported in the other papers. 

I discuss the plenary and poster papers in the "Ecological 

Session" in six broad and somewhat uneven categories, 

with considerable interrelations among them: (1) History 

and Ecological Change, (2) Distribution, (3) Classification, 

(4) Ecology and Physiology, (5) Succession and Diversity, 

and (6) Disease. I analyze strengths, weaknesses, and gaps 

in coverage of the ecology of the pinyon -j uni per type in this 

symposium. Except where noted, all author references here 

refer to papers in this section of these proceedings, and the 

reader is encouraged to study the entirety of each paper. 

History and Ecological Change __ 

Trends since Pleistocene 

Tausch outlined the landscape position held by juniper 

and pinyon in the Great Basin from the Pleistocene to the 

present. He emphasized that climatic change influences the 

key ecological processes that drive vegetation change. Vegetation types such as pinyon-juniper have shifted hundreds 

of miles north and south and also up and down in elevation 

during glacial cycles. 

The fact that substantial changes have taken place in 

the pinyon-juniper woodlands in the past 150 years is one of 

the reasons for this symposium. According to Tausch, this 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

W.A. Laycock is Professor Emeritus, Department of Renewable Resources, 

University of Wyoming, Laramie, WY 82071-3354. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

period was characterized by: (1) a warming climate following the Little Ice Age, (2) the period of the heaviest use by 

European livestock, and (3) a decrease in wildfire frequency. 

These factors, in combination, enabled trees Guniper and 

pinyon) to establish in and then dominate new communities, expand to both higher and lower elevations, and, more 

recently, dramatically thicken in tree densities and canopies of both existing and new stands. 

Harvesting After Settlement 

Young and Svejcar summarized the history of tree harvesting in the pinyon-juniper woodlands in the late 19th 

century-harvesting that mainly provided energy for mining, industries, and domestic purposes. Allover the Great 

Basin, use of pinyon and juniper wood for home heating 

and cooking was widespread until use of fossil fuels became 

common after World War II. 

In the 1860's, the existing pinyon or juniper trees in 

the vicinity of large mining operations in Nevada and 

California were quickly exhausted. The demand for charcoal 

was so great that deforestation became a severe problem. In 

Nevada, Young and Svejcar estimated that 4,000 to 5,000 

acres of woodland had to be cut annually to supply the 

Eureka District. By 1874, the mountain slopes around 

Eureka were denuded of accessible pinyon and juniper for 

20 miles, and the average hauling distance from charcoal pit 

to smelter was estimated to be 35 miles. This 70 mile 

diameter cutting circle covered about 2.5 million acres of 

which 0.6 million acres may have been pinyon-juniper 

woodlands. 

On a much smaller scale, Creque and others examined 

vegetation patterns and change in the past 120 years in the 

Upper Tintic Valley in Utah. Although their study could not 

define presettlement conditions, massive harvesting of 

pinyon-juniper also took place for early mining, domestic, 

and agricultural activities. Domestic fuelwood consumption 

from 1870-1900 was estimated to be as much as 74,000 

cords. Total woodland harvest in the Tintic Valley from 

1870 through 1900 may have been as high as 86,000 ha, with 

74 000 cords cut for domestic fuelwood. All of these figures 

re~resent the maximum possible wood removed and not all 

are well documented. 

The early period of widespread tree harvesting was followed by a the significant regionwide woodland expansion in 

the recent past (Creque and others). West stated that current conditions are far from the presettlement situation 

when much more savanna and less woodland and forest 

existed in the area where relatively dense pinyon-juniper 

stands now exist. 

7 
Role of Fire in Pinyon-Juniper Systems 

Gruell studied fire history based on fire-scarred trees in 

three areas showing a history of repeated fires. Presettlement fire intervals ranged from a mean of 8 years in the 

Walker River area of Nevada, 13 years at the Hart Mountain and Sheldon Refuges in Oregon, to 50 to 100 years in the 

Great Basin National Park in Nevada. In the past, fires 

occurred more frequently on deeper soils which produced 

an abundance offine fuels. Less frequent fires were found on 

shallow soils and rocky sites which produced less fine fuel. 

Gruell concluded that presettlement fires were common 

in the pinyon-juniper woodlands of the Great Basin. This 

fire regime was dramatically altered after settlement because of fire suppression and of heavy grazing, which removed fine fuels. This has resulted in increased density and 

crown cover of pinyon-juniper along with a more recent 

buildup of ground fuels. This has resulted in a shift from 

more frequent, low intensity, small fires, to less frequent 

but larger, high intensity fires. Gruell contended that 

"considering the extent of the fuel buildup, severe fires in 

the Great Basin will continue and perhaps become more 

frequent." West also stated that "The future holds increased probability of crown-fires, invasion by introduced 

annuals and short-lived perennials, and then repeated 

burning and permanent site degradation unless seeding of 

desirable understory takes place expeditiously." Tausch 

predicted the same future scenario. 

Distribution 

Area Covered by Pinyon-Juniper 

Estimates of total area covered by pinyon and juniper 

varied considerably in the papers in the symposium. Some, 

but not all, of the discrepancies are because of differences in 

area considered. 

Author 

West 

Nowak and 

others 

Weber and 

others 

Horman & 

Anderson 

O'Brien & 

Woudenberg 

Bunting 

and others 

Acres 

75 million 

74 million 

99-124 million 

60 million 

45.3 million 

42 million 

Area Considered 

SW U.s. and Mexico 

Not specified 

SWU.S. 

Nevada, Utah, Colo. 

New Mexico, Arizona 

Intermountain West 

NW Great Basin & 

S. Columbia Basin 

Mitchell and Roberts probably reported the most accurate 

figures, based on satellite imagery. They estimated that 

pinyon-juni'per covered 55.6 million acres in the entire 

Western United States. 

Altitudinal Distribution 

Drought and frost during the growing season limits distribution of pinyon-juniper woodlands to relatively narrow 

8 

altitudinal belts on the sides of mountains. In western 

Utah, Harper and Davis found that elevation of pinyonjuniper sites on granite averaged 1,926 m while those on 

sandstone averaged 1,341 m. Lei reported pinyon-juniper 

woodland occupied the area from approximately 1,250 to 

2,6000 m in elevation in southern Nevada. West stated 

that pinyons are less tolerant of drought and early spring 

frosts than junipers and usually dominate the middle 

elevations while juniper tend to dominate both the higher 

and lower elevations of the woodland belt. 

Nowak and others reported that juniper has greater 

drought tolerance and that pinyon is more responsive to 

increased water and nitrogen. Lei studied the environmental variables of a pinyon-juniper woodland along an elevational gradient in a canyon in southern Nevada. Four primary species groups were identified with increasing 

elevation: blackbrush, big sagebrush, singleaf pinyon, and 

ponderosa pine. Species distribution was associated with 

elevation, soil moisture, air temperature, percent bare soil 

and rock cover, and soil depth. 

In contrast to these reported results and published elsewhere, West and others reported that in the western part of 

the pinyon-juniper range, pine dominates or is the only tree 

in the upper elevations of these woodlands. (West N. E., 

Tausch, R. J. and Tueller, P. T. 1998. A managementoriented classification of pinyon-juniper woodlands of the 

Great Basin. Gen. Tech. Rep. RMRS-GTR-12. Ogden, UT: 

U.s. Department of Agriculture, Forest Service, Rocky Mountain Research Station.) 

Classification ________ _ 

Tausch stated that "The understory is central to understanding the ecology and ecosystem function of a site." 

Within the Great Basin, pinyon-juniper woodlands represent multiple communities and ecosystems that are better 

identified by the understory species. This complexity is 

increased and often obscured by successional stages of 

each community. West stated that juniper-pinyon savannas 

and woodlands have understories that are floristically and 

structurally more variable than the overstory. Generally, 

the understory is compositionally similar to that of adjacent 

grasslands, shrub steppes, chaparral, and forests. 

Classification Systems 

Winward reported that, because of the complex geology 

and terrain, past climatic fluctuations and human disturbances, past attempts at classification of pinyon-juniper 

communities have only been marginally successful. He proposed the following step-down (hierarchical) classification: 

Geographic Units (as homogeneous as possible) 

Series-Level based on dominant tree species 

Associations based on a dominant understory shrub 

species 

Sub-Associations based on prominent herbaceous species 

West and others (cited earlier in this paper) published a 

hierarchical approach to classification of pinyon and juniper woodlands that appears similar to, but perhaps more 

comprehensive than, the one presented in the proceedings 

by Winward. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Rust used a similar system to classify pinyon-juniper 

woodlands on 12 research natural areas in southeastern 

Idaho. He identified four series: singleleaf pinyon, Rocky 

Mountain juniper, Utah juniper, and curl-leaf mountainmahogany. Within these series he described 23 plant associations based on differences in understory species. 

Forest Inventory 

About 40 percent of the 45.3 million acres of the pinyonjuniper and juniper woodlands in the Intermountain 

West occur in Nevada and Utah (O'Brien and Woudenberg). 

Net volume of wood was estimated at more than 10 billion 

cubic feet or about 137.5 million cords. About 53 percent of 

the woodland stands in Utah and 67 percent in Nevada 

were estimated to be between 40 and 120 years old. Only 20 

percent of stands in Utah and 9 percent in Nevada are 

more than 200 years old. 

Ecology and Physiology ___ _ 

Seed Dispersal of Pinyon and Juniper 

Chambers and others studied seed dispersal and seedling establishment of pinyon and juniper species. Birds 

disperse pinyon seeds a distance of several meters to 5 km. 

Some birds and rodents make caches of pinyon seeds, 

which are important sources of new tree seedlings. Many 

mammals consume and disperse juniper seeds including 

rodents, rabbits, predators, deer, and livestock. All pass 

some seeds intact, which can enhance germination. 

Chambers and others found that pinyons have relatively 

short-lived seeds that form only temporary seed banks. 

Junipers have a rather continuous seed bank because of 

long-lived seeds with gemination being delayed by impermeable seed coats, immature or dormant embryos, or 

germination inhibitors. Pinyon seedlings often require a 

nurse plant to survive, while juniper seedlings survive in 

open spaces almost as well as under the canopy of shrubs or 

trees. Areas under shrubs and trees often have higher 

concentrations of nutrients and organic matter and higher 

infiltration rates, making microenvironmental conditions 

favorable for many conifers. Ecotones between woodlands 

and adjacent shrublands or grasslands often provide favorable microhabitats for seedling establishment. Over time, 

and without periodic fires, this process would help to explain 

the expansion of the boundaries of pinyon-juniper woodlands in many areas. 

Seed Banks of Non-Tree Species 

Poulsen and others studied the soil seed bank of all 

species in pinyon-juniper sites in central Utah ranging 

from closed stands with minimal understory to open stands 

with excellent understory communities. As tree cover increased, the numbers of understory species and seeds in the 

soil seed bank decreased. The composition shifted from 

perennial grasses and shrubs in the moderately depleted 

and nondepleted understories to annuals and perennial 

forbs in the depleted understory. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Ecophysiological Patterns of Pinyon and 

Juniper 

Nowak and others examined the ecophysiological patterns of pinyon and juniper and found that these trees 

generally are conservative in their acquisition and use of 

resources. Maximum assimilation and conductance rates 

and tolerance to severe water stress are considerably less 

for pinyon and juniper than for sagebrush. These conservative ecophysiological traits of pinyon andjuniperdo not, in 

themselves, provide for success but may benefit the conifer 

species by enhancing establishment and growth under nurse 

plants. The relatively low nutrient content per unit of 

foliage may allow the conifers to produce more foliage 

biomass per unit of ground area than sagebrush. These 

traits coupled with greater longevity allow the conifers to 

establish under nurse plants and then grow and ultimately 

outsize and outlive the shrub competitors. 

Succession and Diversity ___ _ 

Relation of Tree Density to Species 

Diversity 

The development of mature pinyon and especially juniper 

woodlands has often resulted in decreases in the herbaceous 

and shrub understory components. Bunting and others 

studied the effects on species richness caused by thickening 

of Western juniper stands and encroachment onto deeper 

soils in the northwestern portion of the Great Basin. Development of Western juniper woodland vegetation resulted in 

reductions of shrub and herbaceous plant cover and species 

richness. Many perennial herbaceous species were associated primarily with early to mid-seral communities and not 

found in the late seral communities dominated by trees. 

Maximum landscape species richness and species diversity 

would occur when all structural and seral stages are represented within a watershed. This emphasizes the need to 

reintroduce or include smaller scale disturbances, such as 

fire, as a process in landscape dynamics. 

In northeastern Utah, Huber and others also found that 

both alpha and beta diversity were highest in seral communities where pinyon and juniper canopy cover did not 

exceed 20 percent. In woodland communities where canopy 

exceeded 30 percent, both understory cover and diversity 

were severely depressed. 

Overstory/Understory Relationships 

Miller and others presented a model of the conversion of 

shrub steppe to juniper woodlands in the absence of fire in 

eastern Oregon and northeastern California. Perennial forb/ 

grassland and shrub steppe communities are fire driven 

systems. During the early stages of tree establishment, the 

transition is reversible, mainly by fire. Shrubs begin to die 

as the woodlands approach mid development, which decreases the probability of a fire intense enough to kill the 

large juniper trees. By the mid to late stages of this transition, a threshold is crossed where reversal to a shrub steppe 

community is unlikely (See figure 2 in Miller and others). 

9 
Crossing the mid to late development threshold often is 

characterized by a loss of native herbaceous species, possibility of dominance by alien annuals, the potential loss of 

surface soil, and the loss of habitat for many wildlife 

species, which are abundant in the shrub-steppe communities. Tausch discussed other thresholds important to the 

understanding of woodland dynamics. The relationships 

illustrated in the Miller and others' model help explain the 

results of many of the papers in this session. The model also 

would be quite helpful in evaluating potential resource 

problems, determining wildlife habitat values, and setting 

realistic goals and time frames for management. Svejcar, in 

the "Management Implementation Session," also suggested 

that state-and-transition models be developed for pinyonjuniper systems. 

Horman and Anderson studied the effects of removal of 

juniper tree canopy and litter on the \.!nderstory in Utah. In 

undisturbed woodlands, cover, understory plant abundance, 

and seedling emergence were quite low but were higher in 

the under the tree canopy than in the interspaces. Canopy 

removal decreased plant abundance and seedling emergence in the canopy zone but had no effect in the interspace. 

Litter removal had no significant effect on perennial species. 

This study was conducted only for 3 years, possibly too short 

a time for the effects of canopy removal to become evident. 

More likely, this site had crossed the threshold referred to by 

Miller and others, and the understory had lost the ability to 

respond to the canopy removal. 

Naillon and others studied the relation of understory 

species frequency between canopy and interspaces between 

trees at different tree densities. As tree density increased, 

associated herbaceous cover and species diversity decreased. 

Sandberg bluegrass had higher frequency values under tree 

canopy than in the interspace at low tree densities. No 

difference occurred at high tree densities. At all tree densities, cheatgrass frequency values were higher under the 

canopy than in the interspaces. 

Alien Annual Species jn the Understory 

Goodrich and Gale studied frequency of cheatgrass 

(Bromus tectorum) on two relic sites within a pinyon-juniper 

belt in northern Utah. The sites were protected by cliffs and 

steep slopes and probably had little or no historic livestock 

use. One area had burned about 80 years ago and the other 

had an open stand of trees even though it had not burned in 

the past 150 years. Cheatgrass was by far the dominant 

understory species on both sites. Its abundance indicates a 

capacity to drive plant community dynamics both after fire 

and in areas that had not recently burned, and even in 

areas where human and domestic livestock activities have 

been low. They concluded that the concept of potential 

natural communities based on only native species is seriously challenged by the dynamics of cheatgrass. Refusing to 

recognize cheatgrass within the site potential will not reduce its presence nor its potential to dominate a community. 

Tausch reported that the dominance of cheatgrass represents a recognizable threshold in pinyon-juniper woodlands. 

Svejcar, in the "Management Implications Session," also 

discussed the invasion of cheatgrass and other weeds in 

disturbed areas. If a good cover of perennial species exists 

10 

before disturbance, cheatgrass and other weeds often are 

not a problem. If considerable annuals are present, they 

likely will dominate the site after a disturbance, and seeding 

of adapted species may be required (Tausch). A state-andtransition model, including situations with presence and 

absence of cheatgrass and other annuals, would help 

managers make more informed decisions. 

Jones and others studied drought tolerance of small burnet (Sanguisorba minor) and six cultivars of alfalfa 

(Medicago sativa), two nonnative species that might be 

suitable for planting on specific sites. Small burnet was 

more drought tolerant than alfalfa. 

Changes Over Time in Mature Stands 

While large changes have occurred in areas where trees 

have invaded or thickened, re-surveys of mature pinyonjuniper stands reported in this session showed little change, 

at least over relatively short periods. Austin found little 

change over 23 years (1974 through 1997) in trees, shrubs, 

grasses, or forbs in a mature pinyon-juniper community in 

northeastern Utah. In a relict area in Grand Canyon National Park, Brian and others found only slight changes in a 

mature pinyon-juniperwoodland over 38 years (1958 through 

1996). 

Disease ______________________ _ 

Only two papers dealt with diseases of pinyon and 

juniper. Weber and others reported that a number ofpathogens occur on Pinus edulis and Juniperus osteosperma. The 

most frequent pathogens onjunipers are rust fungi. Mistletoe is more common on pinyon than juniper but occurs on 

both species. Mold/mildew diseases, wood rot, needle blight, 

shoot dieback and needle cast are common in juniper. 

In southern Nevada, Lei found that taller Utah juniper 

trees were more likely to be infected by parasitic mistletoe 

than shorter trees. Mistletoe significantly reduced leafwater potentials, vigor, viability, and reproductive success of 

the host tree. 

Discussion __________ _ 

Substantial changes have taken place in pinyon-juniper 

systems over the past 150 years. Tausch provided the historical basis for the Ecological Session by pointing out that 

this period was characterized by a warming climate, heavy 

livestock grazing, and a decrease in fire frequency. After 

the early exploitation of these woodlands for wood, these 

factors enabled pinyon and juniper to establish and then 

dominate new communities as well as thicken in existing 

stands. Young and Svejcar summarized the heavy tree 

harvesting for industrial and domestic purposes since 1900 

before the current expansion and stand thickening. 

Gruell provided evidence of pre- and postsettlement fire 

history for three areas. This type of research needs to be 

repeated all over the Great Basin and other areas where 

pinyon-juniper woodlands now exist. Gruell, West, and 

Tausch indicated that large severe fires covering large areas 

in the future will be the result of crown closure or fuel 

buildup. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
The greatest lack of agreement among authors concerned the total area covered by pinyon-juniper woodlands. 

Figures presented ranged from 45 million to 120 million 

acres. The 55.6 million acre figure of Mitchell and Roberts 

probably was the most accurate because it was developed 

from satellite imagery. 

Tausch stated that the understory is key to the understanding of the ecology and ecosystem function in pinyonjuniper woodlands. The hierarchical classification systems 

of Winward, Rust, and West and others (cited previously) 

start with some large geographic unit, then to the dominant 

tree species, and only then to the dominant shrub and 

herbaceous species. If the understory is, indeed, the key to 

understanding pinyon-juniper systems, then classification 

systems need to recognize that fact in a more positive 

manner. 

Ecological and physiological res_earch reported in this 

symposium that should lead to a better understanding of 

how pinyon-juniper woodlands function included seed dispersal and seedling establishment mechanisms of pinyon 

and juniper, understory seed banks, ecophysiological 

mechanisms of pinyon and juniper species, and species 

diversity at different seral stages. The papers by Miller 

and others and Tausch probably provided the most useful 

synthesis of the processes involved in the conversion of 

shrub steppe to juniper woodland. Miller and others suggested a model showing increase in tree density and corresponding understory changes. If a system crosses a threshold of tree cover and density, the process cannot be reversed, 

and the site becomes a woodland. This model explains the 

results of a great many papers in this session and should be 

read by anyone interested in the ecology or management of 

pinyon-juniper. Svejcar, in the "Management Implications 

Session," recommended that one or more state-and-transition models be developed for pinyon-juniper systems. The 

USDA Forest Service Proceedings RMRS-P-9. 1999 

model proposed by Miller and others along with the 

thresholds defined by Tausch, could be developed into a 

state-and-transition model. 

The Goodrich and Gale paper also is quite important to 

the understanding of the ecology of pinyon-juniper woodlands as well and many other ecosystems. They found that 

an alien species, cheatgrass, was the dominant species on 

two pinyon-juniper stands in Utah that had little or no 

historic disturbance by livestock or humans and 80 to 150 

years since the last fire. They pointed out that a prevalent 

concept in management is that preservation of native 

plant communities will prevent or eliminate cheatgrass 

(and perhaps other alien annuals). This is not consistent 

with reality in many situations. If a woodland with an 

understory dominated by cheatgrass burns, the site then is 

dominated by cheatgrass and other annuals. Because such 

sites may re-burn every 3 to 5 years (West and others), they 

often are permanently converted from a woodland to an alien 

grassland. Thus, the domination of cheat grass is a recognizable and important threshold in these woodlands (Tausch). 

Similar management concepts, such as those that permit 

seeding of only native species in severely disturbed pinyonjuniper stands, likewise may be questionable. Site adapted 

native species are not available in sufficient amounts to 

adequately restore extensive disturbances. To prevent erosion and keep alien annuals from invading, adapted, 

drought-tolerant introduced species often will be required 

to stabilize disturbances until suitable native species become available. In this situation, it seems ecologically 

undesirable and economically unwise to insist that only 

native species be seeded. This is especially true if rather 

large areas have to be seeded to prevent erosion or cheatgrass invasion following extensive wildfires, and if the 

large sums of money required to purchase expensive native 

seed are not available. 

11 
Historic Pinyon and Juniper Woodland 

Development 

Robin J. Tausch 

Abstract-Climate change influences the ecological processes driving regional vegetation change. With the paleoecological and geomorphological perspective of Holocene history, it is apparent that 

each vegetation change interacting with the environment sets the 

conditions for the next vegetation change. Because of interactions 

between vegetation change and environment, particularly for nontree species, pinyon-juniper woodlands of the Great Basin represent 

multiple communities and ecosystems. Multiple successional stages 

occur in repetitive, but constantly changing, mosaics across the 

landscape. Tree expansion over the last 150 years has set up the 

conditions for the possible decline in woodland area from large fires 

over the next 150 years. To manage these woodlands, better definitions of what is woodland versus other communities are needed that 

account for their long-term patterns of change and interacting 

cycles of disturbance and succession. 

To understand the dynamics of Great Basin woodlands, 

knowledge of their development is necessary. At the core of 

current and historic woodland development is climate. 

Through the control of energy and water, climate is the most 

important factor in the occurrence and distribution of ecosystems and communities (Bailey and others 1994). Land 

form is the major modifier of climate. Climate change and its 

topographic modifications influence key ecological processes, 

driving both local and regional vegetation changes 

(Betancourt and others 1993; Woolfenden 1996). These 

changes cascade up and down between scales of space and 

time. History shows us that about the only thing we can 

predict about climate is that it will change. It is when and 

how it will change, and how communities will respond, that 

we largely do not know. 

The combination of available paleobotanical proxy data 

from wood rat midden and pollen records from the late 

Pleistocene through the Holocene reveals that individualistic species responses to climate change have driven considerable vegetation change (Betancourt 1996; Betancourt and 

others 1990; Nowak and others 1994a; Tausch and others 

1993; VanDevender and Spaulding 1979; Woolfenden 1996). 

These records are the most detailed for the last 4,000 to 5,000 

years (Wigand and others 1995). Past environmental changes 

can also equal or exceed the importance of the current 

environmental conditions in determining the growth, development, and competitive and successional dynamics of current communities (Millar 1996, Woolfenden 1996). Each 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Robin J. Tausch is Project Leader, Rocky Mountain Research Station, 920 

Valley Road, Reno, NV 89512. 

12 

change in the vegetation, in turn, sets up the community 

conditions that interact with the next environmental change 

to set the direction and magnitude of the next vegetation 

change. Without an understanding of the history of past 

change, it is not fully possible to adequately explain current 

woodland patterns or ongoing changes. This is particularly 

true for the last 5,000 years and involves a shift in our 

perception of time to scales more appropriate to how Great 

Basin ecosystems function because functions change as an 

ecosystems respond to changing climate (Millar 1997, Tausch 

1996). 

With climate it is often the effects of its variability, and 

particularly its extremes, not the means, that have the most 

influence on community changes (Betancourt and others 

1993). The types, frequencies of occurrence, outcomes of 

extreme events, and how vegetation responds vary with 

location across the Great Basin. Biological and ecological 

changes resulting from climatic variation have been studied 

primarily at the organismic and community level, and more 

rarely, at the ecosystem or regional scale (Betancourt and 

others 1993). Better understanding of historical climatic 

and community changes, and present ecosystem influences, 

at regional scales is central to successful ecosystem 

management. 

On geologic time scales, most ofthe Great Basin is a region 

or zone of transition between northern coniferous forests 

and southern deserts that has shifted hundreds miles north 

and south during each glacial cycle. As community composition has continually changed, both between and within 

glacial cycles, these changes were modified by the topography of the region. There have been major shifts through time 

in the trees' location, their abundance, and their relative 

contribution to communities. 

Historical Changes 

Historical woodland development through the Holocene 

can be divided into 10 time periods. These periods have been 

based primarily on information provided by Wigand and 

others (1995) from the analysis of pollen data. I have modified the number and timing for these periods based on 

additional information from geomorphic studies of the Columbia River system (Chatters and Hoover 1992); from 

Betancourt and others (1993), from west and central Nevada 

woodrat midden (Tausch and Nowak 1998) and geomorphic 

and community studies (Chambers and others 1998), and 

from studies in the Sierra Nevada Mountains (Millar 1996, 

Woolfenden 1996). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Pleistocene: More Than 11,500 Years BP 

Semiarid woodlands were about 1,000 m lower in elevation and 500 to 600 km further south at the last glacial 

maximum about 18,000 years BP (Spaulding 1985; 

VanDevender and Spaulding 1979; Wells 1983; Wigand and 

others 1995; Woolfenden 1996). Woodlands during the Pleistocene were largely limber pine, bristlecone pine, and whitebark pine, and were largely open with the understory communities dominating the cover. The dense pinyon-juniper 

woodlands present today were mostly absent from the Great 

Basin until after about 10,000 years BP (Thompson 1990; 

Woolfenden 1996). Both western and Utah juniper were 

present in the Pleistocene but were apparently scattered 

around lower elevation areas ofthe Great Basin protected by 

topographically modified climate (Nowak and others 1994a; 

Thompson and others 1986; Wigand and others 1995). Pinyon was restricted to the valley floors and mountain slopes 

at the southern edge of the Great Basin (Nowak and others 

1994b; Thompson 1990; Woolfenden 1996). Toward the end 

of this period, pI uvial lake levels were dropping and many 

genera oflarge herbivores were becoming extinct (Betancourt 

and others 1993). 

Early Holocene: 11,500 to 8,000 Years BP 

The climatic conditions of the early Holocene were very 

different than in the previous 100,000 years of the Pleistocene. Climate during the Holocene, however, has also 

never been constant long enough for any strong interspecies 

relationships to develop. In southern Nevada, pinyon-juniper woodlands replaced limber pine at intermediate elevations as temperatures warmed (Thompson 1990; Wells 1983; 

Wigand and others 1995). This time period also saw the 

beginnings of the northward movement of pinyon into the 

Great Basin and expansion of juniper out ofits more northerly refugia (Nowak and others 1994a,b; Woolfenden 1996). 

During this early Holocene period, pinyon was apparently a 

minor component of the juniper dominated woodlands 

(Spaulding 1985; Thompson 1990; Wigand and others 1995). 

The ability of both tree genera to dominate a site increased 

in the Holocene, especially in the absence of disturbance 

such as fire. The species composition of all communities 

continued to change over this period of the Holocene (Nowak 

and others 1994a,b). 

Mid-Holocene: 8,000 to 5,500 Years BP 

This was the warmest part of the Holocene. In the midHolocene the woodlands and upper tree lines were 300 to 500 

m higher in elevation than today (Jennings and Elliot-Fisk 

1993; Wigand and others 1995; Woolfenden 1996). Lake 

Tahoe was also 10 to 15 m below its geologic rim. Trunks of 

trees that established along the lower shoreline during this 

period, and were then drowned when the lake level rose, still 

exist in the Lake (Furgurson and Mobley 1992; Lindstrom 

1990). Many desert shrub species in the Great Basin increased in abundance (Mehringer and Wigand 1990; Tausch 

and Nowak 1998; Wigand 1987; Wigand and others 1995). 

Some expansion in the range ofthe woodlands also occurred. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Early Late Holocene: 5,500 to 4,500 

Years BP 

A gradual but erratic increase in precipitation occurred 

following the mid-Holocene (Chatters and Hoover 1992; 

Davis 1982; Mehringer 1987; Wigand 1987), and there was 

additional migration of both juniper and pinyon northward 

into the Great Basin. This period also had the first evidence 

of western juniper in northeastern California and eastern 

Oregon (Mehringer and Wigand 1990; Miller and Wigand 

1994; Wigand and others 1995). The range in woodland 

distribution continued to slowly increase during this time 

period. 

Neoglacial: 4,500 to 2,500 Years BP 

The Neoglacial period was much cooler and wetter than 

the mid-Holocene (Davis 1982; Grayson 1993; Wigand 1987; 

Woolfenden 1996). Western juniper expansion continued 

into the northernmost Great Basin (Wigand 1987), and this 

expansion accelerated in the middle of the period. Much of 

the remainder of the pinyon and juniper range expansion in 

Nevada and Utah occurred during this period and was 

accompanied by a reduction in desert shrub vegetation. 

Pinyon abundance increased relative to that of juniper 

(Thompson and Kautz 1983). The increase in range for the 

trees was largely at mid and low elevations (Mehringer and 

Wigand 1990). Woodland extent and density at mid to low 

elevations was possibly equal to that present today (Kinney 

1996; Wigand and others 1995, Wigand 1998). Large increases in grass are associated with evidence of periodically 

occurring fire. Upper tree line lowered in elevation in the 

White Mountains (LaMarche 1973), in the Sierra Nevada 

Mountains (Scuderi 1987), and in the Canadian Rockies 

(Luckman 1990). The Great Salt Lake Desert apparently 

flooded during the latter part of the period (Mehringer 1977; 

Thompson and Kautz 1983), and Mono Lake reached its 

highest level since the early Holocene (Stine 1990). 

Post-Neoglacial Drought: 2,500 to 1,300 

Years BP 

Following the Neoglacial there was a significant drop in 

precipitation, but temperatures apparently remained relatively cool (Chatters and Hoover 1992). Coinciding with this 

severe drought was a region wide decrease in woodland 

density and extent and increasing dominance of desert 

shrub vegetation that was dominated by Chenopods, particularly greasewood (Wigand and others 1995). Juniper 

declined less than pinyon (Thompson and Kautz 1983). 

Major geomorphic changes from floodplain construction and 

rapid alluvial fan development occurred to the north (Chatters and Hoover 1992). Similar alluvial fan building and 

aggradation of valley floors, along with reductions in plant 

diversity, occurred in central Nevada during this period 

(Chambers and others 1998). 

13 
Medieval Warm Period: 1,300 to 800 

Years BP 

This period had warmer temperatures (Grove and Swi tsur 

1994) and an increase in precipitation from the previous 

period, but also saw a shift in precipitation with a greater 

proportion coming in late spring and early summer (Davis 

1994; Leavitt 1994). Winter conditions may have also been 

milder (Wigand and others 1995), reducing snowpack and 

lake and stream levels (Born 1972; Stine 1994; Woolfenden 

1996). These climate changes resulted in an increase in 

grass abundance (Wigand and Nowak 1992), and the presence of buffalo (Agenbroad 1978; Butler 1978; Schroedl 

1973). About 1,000 years BP, there was a brief juniper 

woodland expansion in the north and the maximum dominance of pinyon was centered about 1,200 years BP (Wigand 

and others 1995). The Fremont Indian Culture, with its 

corn-based agriculture, occurred in many areas of the eastern Great Basin at this time. 

800 to 550 Years B P 

This is an unnamed dry period that is reflected in tree ring 

studies (Holmes and others 1986; Woolfenden 1996), and the 

reduction of lake levels (Stine 1990). It was also accompanied by cool temperatures and again had a decline in tree 

dominance (Wigand 1987; Wigand and Rose 1990), an increase in desert shrubs, and an increase in fire in some 

locations (Wigand and others 1995). Some of the previous 

extent in woodland distribution was also lost. The Fremont 

Indian Culture disappeared from the Great Basin during 

this time period. 

Little Ice Age: 550 to 150 Years BP 

The Little Ice Age was a cooler and initially wetter period 

during which glacial advances, possibly the largest of the 

Holocene, occurred (N aftz and others 1996; Woolfenden 

1996). Upper tree lines were the lowest of the last 7,000 

years in the Sierra Nevada and growing season temperatures were low until about 1850 (Stine 1996) A gradual 

increase in dominance and range of the woodlands began 

following the decline that occurred following the Neoglacial 

(Mehringer and Wigand 1990). This increase included western juniper in the north and primarily pinyon in the rest of 

the Great Basin (Nowak and others 1994a,b). This expansion in range, although not so much in density, was well 

underway when the first Europeans arrived (Wigand and 

others 1995). 

We have some idea of the plant communities ofthe last 400 

to 500 years of the Little Ice Age because it is the vegetation 

that was in the Great Basin when the first European explorers crossed through it. For climatic periods prior to the Little 

Ice Age, we have much less information on Great Basin 

communities·, but they were different (Woolfenden 1996). 

Species presence information from middens (Tausch and 

Nowak 1998) tell us that during the Little Ice Age, the 

species composition of many Great Basin riparian communities was at least as diverse, particularly in herbaceous 

species, as in any other wetter period of the Holocene. These 

Little Ice Age communities were also different than what is 

14 

present at the same locations today. Even though the Little 

Ice Age represents our best understanding of past vegetation, major gaps in knowledge are still present. 

Despite a similar extent in woodland distribution, tree 

dominance patterns within that range were very different 

during the Little Ice Age compared to what is present today. 

Many sources of evidence, including relict woodlands, tree 

age-class ratios, fire scars, and historic documents (Gruell, 

this proceedings) indicate that particularly during the drier 

(Woolfenden 1996) part ofthe Little Ice Age woodlands were 

more open with the trees either found in savannas or 

confined to scattered fire-protected sites (Wigand and others 

1995). 

Throughout the Little Ice Age, the vegetation ofthe Great 

Basin has been represented by a matrix of nontree-dominated communities with pockets of woodlands and individual trees scattered through it. This appears to have been 

a dynamic equilibrium maintained by many factors including a cold, somewhat dry climate (Woolfenden 1996) and a 

higher fire frequency. These high fire frequencies did not 

occur everywhere. Maybe as much as one-fourth of the 

present woodlands fire return intervals may have been in 

centuries, rather than decades. 

Overall, the geographic range of woodland trees during 

the Little Ice Age was close to what now exists, but the 

abundance within those areas was less. Interestingly, this is 

a pattern that is typically seen during the early stages of 

invasion by a new species. The advance does not occur as a 

solid front but first occurs as pockets or small populations 

establishing in scattered locations across the landscape. The 

scattered advance is then followed by a filling-in of the 

intervening spaces and eventual dominance ofthe area. The 

processes of this last step is what has been occurring in the 

woodlands since the end of the Little Ice Age. 

Recent: 150 Years B P to the Present 

The beginning ofthis period coincides with several important changes in the environment that occurred simultaneously. The most important of these changes were (1) 

cessation ofthe hunting, gathering, and burning by populations of indigenous people that had occurred during the 

Little Ice Age (Creque 1996), (2) a change in climate with 

rising temperatures (Ghil and Vautgard 1991; Woolfenden 

1996), (3) the period of heaviest livestock use of the region 

following European settlement with its effects on plant 

competition and fire potential, (4) a decrease in wildfire 

frequency along with increasing wildfire suppression efforts 

in the latter part ofthe period (Bunting 1994), (5) increasing 

atmospheric CO2 levels that are changing community competitive interactions (Farquhar 1997) and favoring the dominance of large woody perennials (Polley and others 1996), 

and (6) an increasing availability of nitrogen from air 

pollution. 

Whatever the combination offactors were that had maintained the Little Ice Age prevalence of a scattered distribution of trees , they changed with the mid nineteenth century 

end of the Little Ice Age. With those changes, the ability of 

the trees to successfully establish into and dominate many 

new communities increased. Movement of woodlands into 

higher elevations, as well as to lower elevations, has accompanied these recent changes (Blackburn and Tueller 1970; 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Miller and Rose 1995; Tausch and others 1981; West 1984; 

Wigand and others 1995). Dense, tree-dominated woodlands 

are now possibly as much as three times as common as at the 

end of the Little Ice Age (Tausch and others 1981). 

Key to this expansion is the ability of the tree species to 

establish into many new communities (Chambers and others, this proceedings). They clearly have effective methods of 

seed dispersal that results in a sufficient number ending up 

in sites suitable for germination. Once germinated, many of 

the tree seedlings become established into the invaded 

communities and successfully compete with, and eventually 

dominate, the other plant species present (Nowak and others, this proceedings). With their longevity topping 500 

years, the last ice advance ended only a few score generations ago for both pinyon andjuniper (Betancourt and others 

1993). This implies that the increased establishment rate is 

not a new adaptation by the trees, but the result of recent 

environmental changes. 

For the last several thousand years, woodlands throughout the southwest have also been significantly affected by 

direct human manipulation (Denevan 1992; Kohler 1992) 

and the role of humans in past woodland dynamics must be 

considered (Betancourt and others 1993). The major differences between prehistoric management, and management 

occurring following European settlement, have been important contributors to the recent changes in the distribution, 

structure, and composition of the woodlands. 

Current Situation ------------------------ Knowledge of woodland history helps in understanding 

the woodlands oftoday in many ways. About half ofthe plant 

taxa present today in the Great Basin are found scattered 

through the woodrat midden and pollen paleorecord of the 

last 30,000 plus years (Thompson 1990; Nowak and others 

1994a,b). All the associations of plant species with each 

other, and with the communities represented, have changed 

considerably and continuously. This is also true over the last 

4,000 to 6,000 years and has included the distribution and 

density of both pinyon and juniper. These changes have 

occurred too frequently for clear links between soils and 

vegetation to form on a regional basis in Great Basin pinyonjuniper woodlands (West and others 1998). 

Recent management activities have been largely based on 

a view that woodlands are the matrix, and imbedded within 

it are all the species assemblages found in the understory. 

This is a view based on what has been visible over only the 

last halfto three-quarters ofa century. With the full perspective of Holocene history, plant species found in the understory oftoday's woodlands, and in the majority oflocations, 

have generally existed in a variety of shrub and grassdominated communities for far longer periods of time than 

they have in tree-dominated communities. Because treedominated woodlands have been much more temporary or 

transitory, it is the nontree-dominated communities that 

are the matrix within which are imbedded pockets of woodlands of various successional stages. 

Despite the similarity in appearance, pinyon-juniper woodlands of the Great Basin do not represent a single natural 

geographic division or natural land type. Both pinyon and 

juniper have large ecological amplitudes. Species of both 

USDA Forest Service Proceedings RMRS-P-9. 1999 

genera can be found growing with other species ranging from 

Joshua trees at the lower elevations to limber pine and 

bristlecone pine at the upper elevations. Because pinyonjuniper woodlands of the Great Basin represent such a large 

area, they are an assemblage of many ecosystems at more 

regional and local levels that are dominated by one or more 

of the woodland tree species. 

Many of the individual shrub taxa present in Great Basin 

communities can also have wide ecological amplitudes (West 

and others 1978; West 1984; West and others 1998). Although not as large as those for the trees, their range of 

occurrence still must be considered as reflecting real differences in broad-scale environments across the region that 

could be important for management. The same is true for 

many dominant perennial grasses. If the trees were not 

present, the Great Basin area now covered by woodlands 

would be an array of many different communities. This is 

consistent with the size of the region, the range of environmental conditions, and the species diversity present over the 

Great Basin. 

One contribution to our lack of recognition of the shrubgrass communities in tree-dominated areas probably comes 

from a comm unity interpretation where disturbance is something abnormal and external to, or separate from, the community. Although they are suppressed by the dominance of 

the trees, these communities are still largely there. All the 

environmental differences their presence represents are 

still important. The understory is central to the understanding of the ecology and ecosystem function of a site. This is 

probably why there are no species clearly identified with 

tree-dominated pinyon-juniper woodlands as can occur in 

many more mesic forest types. All other species present in 

the woodlands were also part of the sagebrush-grass dominated communities that preceded the trees. The trees can be 

a component of many communities, but history shows their 

dominance only represents one possible stage in the successional cycles of those communities. Thus, for most areas, 

and appropriate time scales, dominance by trees has been 

transitory. 

The location in the basin, the topography, the soils, and 

the climate that dictates the differences between these 

communities still influence how the sites respond to changes, 

even when tree-dominated. The outcome of management 

activities, the affects of introduced exotics, and the types and 

successional patterns following fire are generally independent of the appearance of similarity in the structure in the 

tree layer. Understory community differences are more 

indicative of finer scale environmental controls and carry 

more information on how a specific site will respond if the 

trees are removed by some disturbance. 

Additional community variation occurs because individual 

mountain ranges in the Great Basin are not independent. 

Their relative sizes and, in particular, their orientations to 

each other significantly affect each other's environment as 

they interact with storm system development and movement. These interactions between mountain ranges also 

affect how climate and vegetation change with position on a 

mountain. The environment and vegetation found at a 

specific location on one mountain can vary depending on the 

size, shape, and orientation of adjacent mountains. Interactions between altitude and physiographic position can also 

modify the effects of both latitudinal and longitudinal 

15 
zonation. Because of the general north-south orientation, 

some very long ranges can encompass a considerable range 

of environments. 

The same abiotic component may have a different influence in one species mix than in another, and in one location 

than in another, both between and within mountain ranges. 

Changes in the surrounding landscape can drive changes at 

the site level even if that site has seen minimal change. All 

interact through time to affect and drive future community 

changes. The level of influence that topography, soils, and 

environment have on ecosystems in the Great Basin varies 

with latitude and with altitude in complex interactions. 

Within the context of the entire Great Basin, these variations are present as repetitive mosaics across the landscape. 

This complexity can be both increased and obscured by the 

many successional stages of each community. For example, 

long-term, self-reproducing woodland climax states have 

not existed except in very localized, specialized situations. 

They have been the exception. Functioning woodland and 

non woodland ecosystems and their respective successional 

stages have been connected on a landscape basis at multiple 

levels in complex heterogenous ways. Much ofthis variation 

is now being concealed by tree dominance. In the future, this 

complexity of communities and their interconnections will 

not be exact repeats of what occurred in the past 

(presettlement or Little Ice Age) , particularly because of 

ongoing climate change, the introduction of exotic annuals, 

and the increasing atmospheric CO2. Attempts by management to restore those communities will usually not be 

successful (Millar 1997, Tausch 1996). How large an area is, 

its position on the landscape, the larger context of the 

associated communities in the surrounding the area, the 

presence of introduced species, and the potential interactions with those systems all need to be considered. Because 

no system exists in isolation, how a particular system responds to management is determined in many ways by its 

relationships with those systems that surround it. 

Future Trends 

The next step is to look ahead to what past trends and 

present conditions mean for future trends. There are direct 

implications in the history oflong-term, ongoing changes in 

the successional processes of sites dominated by pinyon and 

juniper that are important for management. Most of what 

has been written about successional changes in pinyonjuniper dominated areas has the stated, or more often 

unstated, assumption that all sites where trees become 

established will end up tree-dominated and then stay that 

way. However, this assumes a stable climate and it ignores 

long-term historic fire patterns which have not been constant, but very different for different for past time periods 

preceding the Little Ice Age. These patterns can be expected 

to change again into the future as the Little Ice Age is left 

further behi'nd. For example, as growth and successional 

patterns in the woodlands have changed over the last several decades, their susceptibility to fire, and the types of fire 

that occur, has changed. Evidence is now accumulating that 

the recent tree expansion and the successional changes 

involved are setting up the conditions for a new set of 

changes driven by large, stand-replacing crown fires that 

16 

will take place over the next 150 plus years (Gruell, this 

proceedings; Tausch, this proceedings). 

With the expansion of the woodlands, and an increased 

density and crown size of pinyon and juniper, distances 

between individual tree crowns have been decreasing. The 

result has been a steady increase in the evenness of crown 

fuels across larger and larger areas, particularly on more 

productive sites formerly dominated by sagebrush-grass 

communities. From the increase in crown fu~ls comes a 

steadily increasing risk oflarge crown fires that can rapidly 

cover those large areas. Such fires appear to be increasing in 

frequency, as well as size, as more and more woodland area 

matures to this condition and the contiguous areas involved 

become larger (Gruell this proceedings). Under the right 

conditions, many thousands of acres of mature woodland can 

now burn in a day. 

In the woodland areas that were savannas during the 

Little Ice Age, the older trees, particularly juniper, have 

sometimes been observed to have several fire scars (Gruell, 

this proceedings). With the tree density increases of the last 

century, many of these former savanna sites often have an 

ingrowth of a high density of increasingly larger, younger 

trees, usually pinyon. Heat levels and flame lengths now 

being generated by these denser tree stands, particularly in 

areas with deeper soils, permit fire to carry up through many 

of the more open woodlands on the steeper adjacent slopes. 

These are some of the locations where fires often did not go 

when fire return intervals were more frequent. After more 

than a century of no fire, when fires do occur in these areas, 

they generally leave no surviving trees. This is the outcome 

from the greatly increased fire intensity that follows over a 

century of climate change, settlement impact, and tree 

expansion in the presence of a reduced fire frequency. 

A large part ofthe historic establishment appears to have 

taken place in areas with deeper, more productive soils. 

These are sites in canyon bottoms and swales, and on 

alluvial fans where the available evidence appears to indicate that during the Little Ice Age, tree establishment and 

growth never got very far before they were removed by fire. 

Now, however, as a result of successful tree establishment, 

large areas of deeper soils are becoming dominated by trees. 

As a result, there are probably more acres of woodland, and 

a greater proportion of the total woodland area, now at risk 

for crown fire than at any time since the Neoglacial, and 

possibly longer. The amount of area in this condition is also 

steadily increasing. 

The worst-case outcome ofthese changing community and 

associated fire patterns is that larger and larger areas of 

woodland could potentially cease to exist as more of the 

woodland area in the Great Basin becomes at risk and then 

burns. Currently, the area of woodland reaching tree dominance each year exceeds the amount burned. This may not 

long be the case, and the next 150 years could eventually see 

the area of the Great Basin that is dominated by woodlands 

decline. They will, in turn, be replaced by new shrubperennial grass-dominated communities, or in the worse 

case, exotic annual-dominated communities. 

Local topography, soils, associated species, environmental conditions, and disturbance types and frequencies can 

likely cause major changes in the way sites respond to a 

disturbance such as fire. Even on the more fire-protected 

types of areas, the relative proportions of various seral 

USDA Forest Service Proceedings RMRS-P-9. 1999 
stages can be much different than what was present during 

the higher fire return frequencies that existed during the 

Little Ice Age. Control of reestablishment patterns after fire 

can be dependent on the composition of the understory 

community present prior to the fire. Clearly pre-identification of these areas by the understory communities and their 

different functional relationships will be necessary for determining proper management actions following fire. 

Because of the extensive area of the Great Basin now 

dominated by trees, only on a small portion will it be possible 

to take management action to alter these trends. In the 

majority of the existing and future tree-dominated areas, it 

will be necessary to develop management strategies to deal 

with the results that follow these large fires. In burned areas 

where native shrub and perennial grass-dominated communities return following fires, the return of the woodlands is 

possible. Where the woodlands are being replaced following 

fire by communities dominated by exotic annuals, the return 

of the woodland could take several centuries or longer. 

Despite the changes, there are areas that have been in the 

past, that are, and that are likely to remain in the future, 

generally immune to fire. These sites result in stands oftrees 

that are more open or scattered and have a more sparse 

understory, and generally support a preponderance of the 

existing old-growth woodlands (Miller and others, this proceedings). In these stands, successional processes are often 

an internal patch dynamics type of regeneration. 

The balance between tree and non tree-dominated communities has always been dynamic. Each has always been 

present and each has always had an important ecosystem 

role. Heavy dominance by one or the other, but particularly 

a monoculture of the trees, seems to have always been an 

unstable situation. We are only beginning to recognize the 

full complexity of the large array of communities that comprise Great Basin woodlands. Relatively little is known 

about the basics of that complexity, the range of future 

changes in woodland ecology, or of the range of possible 

management options that are likely in the future as conditions continue to change. 

Composition changes, community type changes, and 

changes in species locations were dynamic throughout the 

Holocene. The pattern of woodland distribution and successional stage has never been random, but differed with the 

size, intensity, and frequency of fire interacting with differences in environment, topography, and soils. The higher fire 

frequencies of the past were also not uniform over time or 

across the landscape (Woolfenden 1996). But despite these 

continual disturbance and composition changes, a general 

pattern of a mosaic of variously interconnected communities 

and successional stages across the landscape appears to 

have remained. This is a dynamic state that Great Basin 

ecosystems appear to often develop, and which our management activities have often disrupted or simplified (Tausch, 

this proceedings). When this disruption or simplification of 

large areas of Great Basin ecosystems occurs, be it upland or 

riparian, unintended changes and consequences often result. When large-scale increases in community homogeneity 

happen, ecosystem function appears to be restricted or 

limited by the loss of the multiple interconnections between, 

and a reduction in, the range of communities and successional stages that are present. Usually, these unintended 

changes from ecosystem simplification, and the larger areas 

USDA Forest Service Proceedings RMRS-P-9. 1999 

potentially affected by any disturbance, appear to be detrimental to long-term management goals. 

Ecosystems occur at multiple levels of integration and 

nestedness. To be effective management must also occur at 

multiple levels of nested geographic scales. It requires awareness of landscape-scale non equilibrium dynamics 

(Betancourt and others 1993; Sprugel 1991; Tausch and 

others 1993) where both slow localized successional and 

large disturbance-related episodic changes in community 

composition and dynamics are present. Because ecosystems 

are spatially arranged and vertically nested, with complex 

relationships among the hierarchies, we need to provide a 

synthesis of information based on the interrelationships 

across each area or region of a landscape. In acquiring this 

information, it must be remembered that ecosystem boundaries are more open in the Great Basin than almost anywhere else (Bailey and others 1994). 

To be successful, management in these woodlands needs 

to be on a landscape to regional scale that considers the 

heterogeneous, non equilibrium mix of disturbance and 

recovery situations they include. Central to this management of such heterogenous mixing of communities in the 

Great Basin will be a clarification of the definition of what is 

woodland what is not, where woodland is dominant and will 

remain so, and where it either is not or will not remain 

dominant. Such a revised definition needs to include the 

range of disturbance types and disturbance frequencies and 

how they change between communities and over time as 

environmental conditions change. It will be necessary, for 

example, to identify areas where the more frequent fires did 

or did not go in the past. To do this it will be necessary to 

identify the environment (particularly climate), topography, and community characteristics that have controlled the 

past fire patterns and frequencies. Some objective way of 

resolving definitions of woodland versus other communities 

that is dynamic and accounts for longer term patterns and 

cycles of disturbance needs to be found. Finally, because 

many aspects offuture climate and plant community compositions and dynamics will be both new and unknown (Millar 

1997, Tausch 1996), successful management can only occur 

by adequately monitoring the changes and responding 

accordingly. 

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19 
Distribution, Composition, and 

Classification of Current Juniper-Pinyon 

Woodlands and Savannas Across Western 

North America 

Neil E. West 

Abstract-Pinyon -juni per woodlands involve vegetation dominated 

by about seven species of Pinus and 17 species of Juniperus scattered over more than 75 million acres of the Southwestern United 

States and Mexico. Thejunipers are more widespread latitudinally, 

longitudinally, and elevationally than the pinyons. The understory 

is much more diverse and reflects largely local climatic patterns. 

Grasslands and shrub steppes have succ~ssionally preceded pinyon-juniper savanna to woodland on sites with gentle slopes and 

fine soil textures. Excessive livestock grazing and direct fire control 

are the major factors which have led to present tree dominance. 

Tree dominance can be regarded as a sign of ecosystem degradation 

on sites formerly occupied by native herbs and shrubs. On many 

si tes, trees will be even tually replaced by in trod uced herbs following 

fire storms unless proactive management is undertaken. 

Tausch (this volume) has outlined how pinyon-juniper 

woodlands came to be. My task is to outline where these 

woodlands and savannas are presently found and how they 

currently vary in tree dominance and understory composition across the western half of the North American midsection. I will conclude with suggestions of how this information 

can be applied in land management. 

Longitudinal and Latitudinal 

Patterns of Tree Dominance -----

I am considering here all hinds with semiarid climates 

west of 103° W.long. in North America currently occupied by 

at least one drought-tolerant juniper (section Sabina) and! 

or one drought-tolerant pine (subsection Cembroides = the 

Pinyons). According to Kuchler (1970), this amounts to 

about 75 million acres in the United States (Fig. 1) and an 

unknown additional area within Mexico. Juniper-Pinyon 

woodlands and savannas as a whole are a very coarse 

category, only useful when comparing nationally or regionally to other coarse (internally heterogeneous) categories 

such as yellow pine forests or sagebrush steppe. 

The most obvious way to begin finer subdivision of these 

lands is to consider what the dominant trees are. Table 1 

indicates the distribution of the major tree species in juniper-pinyon savannas and woodlands across western North 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Neil E. West is Professor, Department of Rangeland Resources, Utah State 

University, Logan, UT 84322-5230. 

20 

America. Junipers are much more widespread than pinyons. 

The furthest north that self-sown pinyon occurs is in extreme southern Idaho. Thus, juniper only woodlands and 

savannas occur north of there. Pure pinyon woodlands, 

dominated by Pinus monophylla, exist only in extreme 

western Nevada and adjacent California where summer 

precipitation is minimal. From about 38° N lat. southward, 

pinyons, junipers, and oaks (Quercus spp.) become intimately intermingled (West 1998). 

Figure 1-Geographic distribution of juniper-pinyon 

woodlands in the Western United States (according 

to KOchler 1970) with J's indicating pure stands of 

Juniperus occidentalis in the Pacific Northwest and 

J. scopulorum in the Northern Rocky Mountains and 

Great Plains. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 1-Distribution of principal tree species in juniper-pinyon savannas in various sections of western North America. Nomenclature follows Flora 

of North America Editorial Committee 1993. 

Area 

British Columbia and Alberta 

Interior Pacific Northwest (Oregon, Washington, Idaho) 

Northern Rocky Mountains and adjacent Plains 

(Montana, Wyoming) 

Pines Junipers 

Juniperus scopulorum 

J. occidentalis 

J. scopulorum 

J. osteosperma 

J. virginiana 

Others 

Eastern and Central Great Plains 

Great Basin 

Colorado Plateau 

Pinus monophylla 

P. edulis 

J. osteosperma 

J. osteosperma 

Southern Great Plains and J. ashei 

Edwards Plateau 

Mogollon Rim P. edulis 

J. pinchotii 

J. monosperma 

J. deppeana 

Cupressus arizonica 

Baja California Norte (Sierra Juarez) 

Sierra Madre Occidental 

Big Bend-Trans Pecos 

P. quadrifolia 

P. cembroides 

P. cembroides 

J. californica 

J. coahulensis 

J.deppeana 

J. flaccida 

Quercus spp. 

Quercus spp. 

Sierra Madre Oriental P. cembroides J. coahulensis 

J. flaccida 

Quercus spp. 

J. monosperma 

Serranias Meridionales del 

Altiplano Potosino 

P. ayachuite 

P. cembroides 

P. joharinis 

J. flaccida Quercus spp. 

Sierra Madre del Sur 

Sierra Madre de Chiapas 

Elevational Patterns of Tree 

Dominance 

P. teocote 

-------------------------------- Elevational segregation is usual in regions where both 

pinyons and junipers occur. Pinyons, being less tolerant of 

drought and cold than junipers, usually dominate in the 

middle elevations where both occur. Junipers tend to dominate both the higher and lower elevations of the woodland 

belt of Intermountain mountain ranges. 

Within a given region, the density of woodland, both 

historically and currently, is strongly related to topoedaphic 

gradients. The trees persisted throughout past centuries on 

steeper, rockier, and thus less burned sites. Less steep sites, 

especially those with finer textured soils are where savannas, grasslands, and shrub steppes have occurred in the 

past. Various densities of younger trees now occur on such 

sites, largely because of new fire and grazing regimes recently imposed by Euroamericans. Understanding these 

dynamic relationships is a key to managing the current 

situations. For instance, Creque and others (this volume) 

USDA Forest Service Proceedings RMRS-P-9. 1999 

J. comitana 

J. gamboana 

J. monticola 

describe the vegetational and environmental changes in 

semiarid portions of upper Tintic Valley, Utah. They delineated ecological sites based on soils, topography, and 

vegetational history. These stratifications can then focus 

local managerial actions to where it is most justified and 

responsive. 

Patterns in Understory 

Juniper-pinyon savannas and woodlands have understories that are both floristically and structurally more variable 

than the overstory. Generally the understory is compositionally similar to that of adjacent grasslands, shrub steppes, 

chaparral and forests (West and others 1975; West and 

Young 1998). For instance, in the western juniper woodlands and savannas ofthe Pacific Northwest, the understory 

is mostly a mixture of sagebrushes (Section Tridentatae of 

Artemisia) and cool season bunchgrasses. The relatively wet 

winters and dry summers there favor plants that can either 

complete their growth before midsummer, like the cool 

21 
season grasses, or utilize deep soil moisture, as do the trees 

and shrubs (Flanagan and others 1992). 

South and east of the Pacific Northwest, the portion of 

warm season bunch and sod grasses increases and the 

amount of shrubs declines as the fraction of total annual 

precipitation received during the summer increases. Juniper and pinyon stands of New Mexico, Texas, and northern 

Mexico thus have more half-shrubs (suffrutescents), such as 

Senecio longilobus, Gutierrezia spp., Brickellia spp., Haplopappus spp., and Salvia spp. and succulents, such as various 

cacti and monocots (for example, Agave spp., Nolina spp., 

Yucca spp., Dasylirion spp.) than true shrubs. Warm season, 

C4 grasses which dominate are from the nearby semidesert 

grasslands or southern mixed and shortgrass prairies, incl uding species ofAristida, Digitaria, Eragrostis, Bouteloua, 

Hilaria, Sporobolus, Muhlenbergia, Schizachyrium, Botriochloa, Lycurus, Piptochaetum, and Leptochloa, where not 

excessively grazed (Moir 1979; Pieper 1992). 

Forbs associated with juniper-pinyon savanna or woodlands also display distinctive geographic distributions. Understory forbs injuni per stands ofthe Pacific Northwest and 

Great Basin are derivatives of the tree-dominated Arctotertiary Geoflora (Axelrod 1976). Principal genera are Lupinus, Penstemon, Castelleja, Balsamorhiza, Allium, etc. On 

the Colorado Plateau and south and east ofthat region, forbs 

associated with juniper and pinyons are mostly derivatives 

of the Madro-tertiary Geoflora (Axelrod 1958), a heat-tolerant group of plants. Example genera are Croton, Euphorbia, 

Ipomea, Solanum, Polygala, and herbaceous Salvia (Pieper 

1992; Romero Manzanares and others 1998). Abundance of 

annuals varies greatly from year to year (Treshow and Allan 

1979) making them oflittle value as indicators of other than 

near term climatic influences. 

Vegetation Dynamics 

The foregoing "sna pshot" of how we currently findj uni perpinyon dominated vegetation is incomplete without considering the dynamics of the vegetation on several scales in 

time and space. Tausch (this volume) covered the "deep" 

past. Focus on the more recent and local can be found in 

GrueH, Young, and Harper (this volume). Rather than repeating their stories, all I will offer here is the fact that the 

current conditions are far from the pre-Euroamerican situation when much more savanna (grassland or shrub mosaic 

with scattered trees) and less woodland (trees are the dominant matrix) and forest (where numerous tree crowns touch) 

existed. 

The local plant community structure where junipers and 

pinyons are involved shows at least two phases (Fig. 2); a 

tree-centered phase where microclimates and soils are controlled by the trees; and a non-tree dominated open interspace where some mixture of shrubs, grasses, and forbs 

prevail. Everett and others (1983) add a third phase, the 

drip-line. As trees have become the matrix, many attributes 

ofthese ecosystems, such as the hydrologic and fire regimes, 

native animal and microbial communities have been altered 

as well (West 1998). Full expression of tree dominance, 

because it leads to diminished understory, has a negative 

influence on floristic and faunistic richness (West 1998). 

Long periods of exclusion oflivestock grazing do little to aid 

22 

Pre-European 

Savannah: 

dependent on 

frequent ground 

fire; least 

amount of 

erosion 

Turn of 20th 

Century: livestock grazed 

away grass 

fuels; left 

unprotected 

interspaces; 

beginning of 

accelerated 

erosion and 

shrub invasion 

Present: larger 

trees; shrubs 

died; no 

understory 

except microphytes; 

continuing 

accelerated 

erosion in 

the interspaces 

Future: all 

perennials. 

killed by midsummer fire 

storms. replaced 

by cheatgrass 

and other 

introduced 

annuals; 

reburns 

frequently; 

accelerated 

erosion 

when bare 

Diversity declines ----------------~-­

Sustainability declines ----------------i __ 

Aesthetics decline -------------------

Figure 2-Depiction of how juniper-pinyon woodland structure changes through successional time 

(earlier to left, later to right). Broken lines are outer 

limits of tree roots. 

recovery of the understory. Increased elk, feral horses, and 

jackrabbits can keep the diminished understory in check 

(Yorks and others 1994). 

Whether these trends toward tree dominance are 

degradational or aggradational is a much disputed topic. 

One's conclusions on this issue determines whether proactive or custodial management is to be favored. While conservation biologists (for example, Belsky 1996) favor hands-off 

management of these woodlands, many others, myself included, regard the changes on most ecological sites as 

degradational (West 1998), and thus meriting proactive 

management. 

Numerous forces have independent influences on tree or 

interspace-dominated phases of juniper-pinyon savannas 

and woodlands (Table 2). Causes of vegetational change are, 

however, rarely singular or simple. Synergistic interactions 

are the norm. The major compound effect is how livestock 

reduced the fine continuous fuel when savannas prevailed 

and along with both direct and indirect reductions in fire, 

allowing the trees to increase. Trees now control most sites 

and accelerated erosion prevails where slope and surface soil 

texture allow (Davenport and others1997). 

Management Implications 

The future holds increased probability of crown-fires, 

invasion by introduced annuals and short-lived perennials, 

and then repeated burning and permanent site degradation 

unless seeding of desirable understory takes place expeditiously. Different portions of the vast juniper-pinyon type 

have and will change differently. Each ecological site presents different potential in response to both passive and 

active management. Winward (this volume) tells you how 

we can recognize these differences and use them for guiding 

management activities. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 2-Summary of forces changing the balance between trees and 

perennial grasses in pinyon- juniper woodlands. P = pinyons, 

J = junipers, + means that the growth form increases when 

the given variable increases, - means that the growth form 

decreases when the given variable increases. 

Forces Trees Grasses 

Climate 

cool, wet (P) + 

warm, dry (J) + 

increasing CO2 in atmosphere + 

Grazing 

Extinct browsers + 

Livestock + 

Elk + 

Feral horses + 

Saw flies + 

Fire + 

Tree harvest 

Animals 

Jays and nutcrackers (P) + 

Chipmunks and ground squirrels (P) + 

Thrushes (J) + 

Rabbits and hares (J) + 

Livestock + 

Parasites + 

Pathogens + 

References --------------------------------- Axelrod, Daniel. 1958. Evolution of the Madro-tertiary Geoflora. 

Botanical Review 24:433-509. 

Axelrod, Daniel I. 1976. History of the coniferous forests, California 

and Nevada. Berkeley, CA University of California Publications 

in Botany 70. 

Belsky, A J. 1996. Western juniper expansion: Is it a threat to arid 

northwestern ecosystems? Journal of Range Management 27: 

91-96. 

Davenport, D. W.; Breshears, D. D.; Wilcox, B. P.; Allen, C. D. 1998. 

Viewpoint: Sustainability of pinyon-juniper ecosystems: A 

USDA Forest Service Proceedings RMRS-P-9. 1999 

unifying perspective of soil erosion thresholds. Journal of Range 

Management 51: 231-240. 

Everett, R L.; Sharrow, S. H.; Meeuwig, R O. 1983. Pinyon-juniper 

woodland understory distribution patterns and species associations. Bull. Torrey Bot. Club 110: 454-463. 

Flanagan, L. B.; Ehleringer, J. R; Marshall, J. D. 1992. Differential 

uptake of summer precipitation among co-occurring trees and 

shrubs in a pinyon-juniper woodland. Plant Cell and Environment 15: 831-836. 

Flora North America Editorial Committee. 1993. Flora of North 

America, Vol. 2, Pteridophytes and Gymnosperms. New York, 

Oxford University Press. 

Kuchler, Arthur W. 1970. Potential natural vegetation map (map at 

scale of1:7 ,000,000) In: The national atlas of the U.S.A pp. 90-91. 

Washington, D. C., Government Printing Office. 

Moir, W. H. 1979. Soil vegetation patterns in the central Peloncillo 

Mountains, New Mexico. American Midland Naturalist 102 (2): 

317-33l. 

Pieper, R D. 1992. Species composition of wood land communities in 

the Southwest. In: Ffolliott, P. F.; Gottfried, G. J.; Bennett, D. A; 

Hernandez, V. M.; Ortega-Rubio, A; Hamre, R H. tech. coords. 

Proceedings-Symposium on ecology and management of oak and 

associated woodlands: Perspectives in the southwestern U.S. and 

northern Mexico. Ft. Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station Gen. Tech. Rep. RM-218. 

Romero Manzares, A; Garcia Moya, E.; Oyama Nakagawa, K.; 

Passini, M.-F. 1998. Los inventarios floristicos y la inerciaresiliencia en los pinon ares meridinonales de San Luis Potosi. 

Boletin Sociedad de Mexico (in press). 

Treshow, M.; Allan, J. 1979. Annual variations in the dynamics of 

a woodland plant community. Environmental Conservation 6: 

231-236. 

West, N. E.; Rea, K. H.; Tausch, R J. 1975. Basic synecological 

relationships in juniper-pinyon woodlands. pp. 41-53 In: Gifford, 

G. F.; Busby, F. E. eds. The pinyon-juniper ecosystem. A symposium. Utah Agriculture Experiment Station, Logan, UT. 

West, N. E. 1998. Juniper-pinyon savannas and woodlands of 

western North America In: Anderson, Roger C.; Baskin, Jerry C. 

eds. Vegetation of Savannas and Barrens of North America. New 

York: Cambridge University Press (in press). 

West, N. E.; Young, J. A 1998. Vegetation of inter mountain valleys 

and lower mountain slopes In: Barbour, M. A; Billings, W. D. eds. 

North American Terrestrial Vegetation. Second Edition. New 

York: Cambridge University Press. 

Yorks, T. P.; West, N. E.; Capels, K. M. 1994. Changes in pinyonjuniper woodlands in western Pine Valley between 1933-1989. 

Journal of Range Management 47: 359-364. 

23 
Historical and Modern Roles of Fire in 

Pinyon-Juniper 

George E. Gruell 

Abstract-Fire history investigations were carried out in three 

widely separated Great Basin pinyon-juniper woodlands in eastcentral Nevada, southeastern Oregon and northwestern Nevada, 

and western Nevada. Study results suggested frequent fires on 

deep soils that produced an abundance offine fuels and infrequent 

fires on shallow soils and rocky sites where fuels were sparse. 

Decades of intensive livestock grazing and successful fire suppression in pinyon-juniper woodlands have resulted in a shift from low 

intensity fires to high intensity fires. This shift has been the result 

oflarge increases in woody fuels and introduction of exotic grasses. 

Considering the extent of fuel buildup, severe wildfires in the 

Great Basin will continue and perhaps become more frequent. 

Charred wood and tree stems bearing fire scars indicate 

that historically fire influenced succession in pinyon-juniper woodlands. Researchers investigating pinyon-juniper 

ecology have noted the importance of fire as a historic 

disturbance agent (Arnold and others 1964; Humphrey and 

Mehrhoff 1958; Miller and Rose 1995; West 1988;). Past 

fires can be dated by study of fire scars on tree rings. 

However, in contrast to mixed conifer forests where firescarred ponderosa pine (Pinus ponderosa) or Jeffrey pine 

(P. Jeffreyi) are common; the relatively low number of fire 

scars in pinyon-juniper woodlands and their restriction to 

sites that did not readily burn, limits our ability to accurately determine fire history (Gruell 1997a). The few fire 

history studies carried out in pinyon-juniper woodlands 

show variations in fire frequency. Young and Evans (1981) 

concluded that between 1600 and 1850, there were periods 

of up to 90 years that western juniper (Juniperus occidentalis) growing on low sagebrush (Artemisia arbuscula) sites 

of northeastern California showed no evidence offire scars. 

Burkhardt and Tisdale (1976) reported average fire intervals ofless than 20 years in climax western juniper on the 

Owyhee Plateau of southwestern Oregon. Chappel (1997) 

reports a mean fire interval of 50 years for four pinyonjuniper sites on Monroe Mountain south of Richfield, Utah 

and she considered this to be a conservative estimate of the 

fire interval. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

George E. Gruell is a retired U.S. Department of Agriculture, Forest 

Service, Research Wildlife Biologist, 1959 Ash Canyon Road, Carson City, 

NV 89703. 

24 

Study Areas and Methods 

Between 1990 and 1997, I investigated fire frequency in 

pinyon-juniper woodlands at three widely separated localities ofthe Great Basin. They incl uded Great Basin National 

Park in east-central Nevada, Hart Mountain-Sheldon Refuge complex in southeastern Oregon and northwestern 

Nevada, and the Walker River Watershed Project area in 

western Nevada. Fire-scarredpinyon(P. monophylla), Utah 

juniper (J. osteosperma) and western juniper were cut with 

a chainsaw following careful search of study areas. Surfaces of cross-sections were later sanded smooth and annual rings were counted under magnification to determine 

the approximate year of scarring. This procedure did not 

include dendrochronological cross-dating as described by 

Stokes and Smiley (1968). The fortuitous presence of ponderosa or Jeffrey pine provided a unique opportunity to 

collect more definitive data in each of the study areas. 

Ponderosa and Jeffrey pine are excellent recorders offire 

since they are long-lived, fire resistant, have clear annual 

growth rings, and occupy sites that were fire susceptible. 

Great Basin National Park 

This study entailed removal of fire scars from 23 pinyon 

and three juniper in four locations representative of variations in pinyon-juniper woodlands in Great Basin National 

Park (G BNP), a 30,840 ha (77,100 acre) portion ofthe South 

Snake Range in east-central Nevada (Gruell and others 

1994). Increment coring of73 pinyon was also carried out to 

determine the approximate ages of post-fire regeneration. 

Intact fire scars were found on or near 16 of20 macro plots 

that had previously been established for purposes of classifying Potential Native Plant Communities (Eddleman and 

Jaindl 1994). Although singleleaf pinyon, Utah juniper, 

and curlleaf mountain-mahogany (Cercocarpus ledifolius) 

all showed scarring, pinyon yielded the best scar samples. 

The probability of locating sound fire scars was low because: (1) a majority of trees in the study area were too 

young to bear scars of pre-1900 fires, (2) most trees old 

enough to bear fire scars were growing in the protection of 

boulders or on sites where fuels were sparse (areas unlikely 

to burn), and (3) some fire scars had been destroyed by 

carpenter ant excavations. 

Hart Mountain and Sheldon Refuges 

The historic influence of fire on plant succession, plant 

communities, and wildlife habitat was studied during 

1994-95 at Hart Mountain National Antelope Refuge 

(HMNAR), Oregon and Sheldon National Wildlife Refuge 

(SNWR), Nevada (Gruell1995). These refuges are situated 

USDA Forest Service Proceedings RMRS-P-9. 1999 
in the volcanic plateau region of the Great Basin. Vegetation composition in this shrub steppe community is dominated by mountain big sagebrush (A. tridentata subsp. 

vaseyana). Western juniper covers less than 4 percent of the 

area. Field studies included aging of curlleaf mountainmahogany and western juniper, collection of fire scars from 

trees, and repeat photography. 

The opportunity to evaluate historic fire frequency on 

HMNAR and SNWRwas severely limited by the scarcity of 

trees that survived and recorded past fires by scarring. 

Analysis of 36 multiple scarred aspen provided no definitive information on fire return intervals. Only nine trees 

were old enough to have recorded fire before 1880. Of these, 

two were scarred. Six trees were scarred in the 1890's, 

apparently by causes other than fire. 

Insight on the frequency of historic fires was made 

possible by the presence of scarred ponderosa pine in a 

12 ha (30 acre) stand growing in association with western 

juniper at Blue Sky on the lower east slope of Hart Mountain. No other ponderosa pine occur on the refuges excepting scattered individuals at high elevations at HMNAR and 

several trees in an isolated stand growing on bare mineral 

soil at SNWR. The Blue Sky stand is almost entirely 

composed of second-growth (Simonson 1975) that regenerated following cutting of nearly all trees in 1866-67 by the 

U.s. Cavalry for construction material and fuel at Fort 

Warner (Shaver and others 1905). A few large pines were 

not cut, including a "catfaced" tree with multiple scar 

wounds. A cross-section was removed from this tree and 

from a stump that contained multiple fire scars. 

Walker River Watershed Project Area 

This study was conducted in the Walker River Watershed Project (WRWP), an area encompassing 157,100 ha 

(392,750 acres) inclusive ofthe east slope of the Sweetwater 

Mountains, the Pine Grove Hills, and the west slope of the 

Bodie Hills (Gruell 1997b). Pinyon dominates the landscape. Scattered juniper is intermixed with pinyon, being 

primarily found on south slopes and dry sites at lower 

elevations. 

A collection of fire scars from 22 pinyon and Jeffrey pine 

was made during June-July 1997 in the Little Frying Pan 

and Desert Creek drainages ofthe Sweetwater Mountains, 

Nye Canyon and a nameless canyon on the northeast side 

of Bald Mountain in the Pine Grove Hills, and the Masonic 

Gulch area in the Bodie Hills. Random searches were made 

until three or more trees bearing fire scars were located. 

The size of the search area varied according to fire scar 

availability. Few fire-scarred pinyons were found in areas 

where the trees were young (less than 130 years of age). 

Those bearing fire scars were widely distributed on fire 

resistant sites. Except for two trees in isolated stands in the 

Pine Grove and Bodie Hills, fire-scarred Jeffrey pine were 

confined to the Little Frying Pan drainage where scattered 

stands grew on sites susceptible to fire. Trees with welldeveloped scars were sampled by removing a cross-section 

from each with a chain saw. Between four and nine samples 

were collected from each area. 

Emphasis was placed in the Little Frying Pan area 

because the Jeffrey pine intermixed with pinyon and 

USDA Forest Service Proceedings RMRS-P-9. 1999 

juniper exhibited a highcomplementoffire scars. Although 

Jeffrey pine grows in association with pinyon-juniper on 

the lower east slope of the Sierra Nevada, they are not 

normally present in Great Basin woodlands. Six fire-scarred 

Jeffrey pine (four live trees and two stumps) and three 

pinyon were sampled. Although the cambial ring year of the 

stumps was unknown, historical accounts (Kerston 1964; 

Paher 1970) suggest these trees were cut in the 1860's. An 

1868 cutting date was assigned to the stumps after synchronizing their most recent fire scars with those on nearby 

live trees (Arno and Sneck 1977). 

A master fire chronology was developed for the Little 

Frying Pan area according to the geographical position of 

sample trees. Questionable fire years were adjusted with 

those considered to be the most probable years of scarring 

(Arno and Sneck 1977). The probability of false rings, 

missing rings, and the deteriorated state of counting surfaces reduced the accuracy of ring counts on portions of 

some samples. 

Thus, the fire history statistics are considered reasonably accurate, but no exact. A master fire chronology was 

not prepared for the Desert Creek, Bald Mountain and 

Masonic areas because of the minimal number of fire scars 

on the samples collected. 

Three historical photographs taken during the period 

1899-1906 were rephotographed in the Bodie Hills and the 

east slope of the Sweetwater Mountains. These scenes 

aided interpretations of plant succession by providing 

visual evidence of composition and structure during early 

stages of EuroAmerican settlement (Gruell 1997b). 

Results __________ _ 

Great Basin National Park 

Data and field observations demonstrated that fire played 

a major ecological role in pinyon-juniper woodlands of 

G BNP over the past several hundred years. Insight into fire 

frequency in the 1800's and 1700's within four macroplot 

complexes was provided by fire scar samples. These data 

showed a com plex and variable fire history tha t largely took 

place before 1860. Pooling of 35 datable fire scars revealed 

that 3 percent of the fires occurred in the 1900's, 76 percent 

in the 1800's, and 21 percent in the 1700's or earlier. Pre1900 fire frequencies varied considerably depending on 

aspect, topography, and ignition source. Apparently fires 

occurred at close intervals on north-facing slopes, in canyon 

bottoms, and in other localities where fine fuels were 

sufficient to carry fire. Quantitative evidence suggested 

that north-facing slopes in the Snake Creek and Strawberry Creek drainages burned on the order of 15-20 years 

(Gruell and others 1994). This figure may be conservative 

considering the low number of scars in the sample. 

Close fire intervals were apparently the product oflightning and Indian ignitions. Indians intentionally set fire to 

vegetation for a variety of reasons including production of 

grass seed and other food plants, stimulation of willow 

(Salix spp.) shoots used in basket-making, immobilizing 

crickets and grasshoppers, drivingjackrabbits (Lepus spp.), 

clearing campsites, and signaling between bands (Cooper 

1961; Gruell1985; Lewis 1985; Moore 1972; Stewart 1963). 

25 
Intentional or escaped fires could have spread from the 

valley or canyon bottoms to adjacent slopes wherever fuel 

continuity allowed. 

Contrastingly, on rocky landscapes containing localized 

patches of flammable fuels, it appeared that fires of any 

appreciable size occurred infrequently. The limited fire 

scar evidence suggests that fire return intervals were 50 to 

100 years or longer. These areas included the drier southfacing slopes and some west-facing slopes on the west and 

south end of the Snake Range. Under extreme conditions, 

fire apparently spotted into available fuels, thereby creating a mosaic of burned and unburned landscape. 

By design, fire scar sampling was confined to pinyon and 

juniper trees at previously established macroplots which 

did not support ponderosa pine. Ponderosa pine was present, 

however, in some localities at higher elevations where they 

are associated with pinyon and juniper. Because ofponderosa pine's proclivity to scar, a sample was taken from a 

stump at about 2,500 m (8,200 ft) on the Lehman Creek 

Scenic Highway west of Baker, Nevada. This tree had been 

scarred 8 times in a 124-year period for a mean fire return 

interval of 18 years. The longest interval was 29 years, 

while the shortest was 8 years. The locality in which the 

stump was located had burned periodically as evidenced by 

charred wood and multiple fire-scarred trees and stumps. 

These data are consistent with the fire-scarred pinyon, 

which suggest vegetation occupying deep soils on GBNP 

burned frequently before settlement by EuroAmericans. 

Fire has not been a significant factor in the Snake Range 

since EuroAmerican settlement. As recalled by Wayne 

Gonder, a local rancher, the largest fire in the South Snake 

Range in modern times took place between 1908-1910 

covering an area of80-120 ha (200-300 acres). U.S. Department of Agriculture, Forest Service fire reports during the 

29 year period between 1959-1988, show an average ofless 

than 3 fires a year (total 83 ) suppressed in the Snake Range. 

Nearly all fires were less than 1 ha, excepting three that 

were between 4 and 24 ha (10 and 60 acres). Lightning 

ignited nearly 90 percent of all fires. Although significant 

fires have not occurred in this century, these woodlands 

ha ve the potential to fuel high intensity fires during periods 

of hot temperatures and strong winds. 

Hart Mountain and Sheldon Refuges 

Collectively, samples cut for purposes of aging included 

48 mountain-mahogany, 43 western juniper and six ponderosa pine. Thirty-eight mahoganies at HMNAR averaged 

81 years old and ranged between 54 and 109 years. This 

suggested that current stands were composed mainly of 

trees that established after 1880. Ten cross-sections removed from varying diameter mahogany growing on deep 

soils on Badger Mountain (SNWR), showed an average age 

of 89 years (range 55-137). A previous study that included 

aging of mahogany on Badger Mountain suggested that tree 

age ranged from 30-145 years (Tiedemann and Furniss 1985). 

Collectively, 94 percent of the juniper associated with 

mountain big sagebrush were of post-1900 origin. These 

trees averaged 82 years old (range 59-110). Junipers associated with low sagebrush exhibited a greater average age 

(143 years) and greater variance in age (range 63-289 

years) compared to juniper associated with mountain big 

26 

sagebrush. These data suggest that fuels on the more 

productive big sagebrush sites supported a fire regime that 

burned more often than that in low sagebrush where fuels 

were light and discontinuous. Hence, tree encroachment of 

big sagebrush communities was inhibited, while on low 

sagebrush sites that burned infrequently and at low intensity, trees were able to persist. 

Analysis of the scar data from Blue Sky showed that the 

two sample trees had recorded a total of 9 fires within an 

area ofless than 20 ha (50 acres) during the 10 I-year period 

1760-1861. This suggested a composite mean fire-return 

interval of 13 years (Arno and Sneck 1977). Fire intervals 

ranged from 3 to 32 years. This record appears conservative 

considering the limited number of old pine (greater than 

200 years of age) that had potential to record fire before 

EuroAmerican settlement. It was also likely that the two 

trees sampled did not unerringly record every fire because 

of variations in fuel loading . Furthermore, the cross-section 

from the scarred stump did not contain a complete record of 

the original fire scars due to rot. 

The short mean fire interval indicated by the Blue-Sky 

data suggested grass dominance on deep soils. Recent 

prescribed fires in the vicinity of Blue Sky demonstrate the 

potential for dominance of a grass sere following fire in the 

shrub steppe. Abundant grass fuels would have been receptive to recurrent burning upon being ignited by lightning or 

Indians. Further evidence of frequent fires in the shrub 

steppe is indicated by the expansion of woody vegetation 

since the late 1800's. There is almost a complete absence of 

snags, stumps, and charred wood within existing stands of 

pine, juniper, and mahogany growing on deep soils. Had 

woody vegetation comprised significant cover historically, 

residual material would be very apparent in these tree 

stands today. Substantial increases of juniper and mahogany on HMNAR and SNWR was also documented by 

retake of five historical photographs (Gruell 1995). 

Modern wildfire was not a significant disturbance factor 

on SNWR until 1988 when 840 ha (2,100 acres) burned on 

Bald Mountain. Between 1945 and 1967, 9 of 10 fires 

suppressed burned less than 1 acre. One fire in sagebrush 

reached 40 ha (100 acres). During this era heavy utilization 

of fine fuels by livestock had essentially removed the potential of fires to spread. Fire occurrence at HMNAR has 

followed the same trend except that three fires ranging in 

size from 2,400 ha (6,000 acres) to 6,400 ha (16,000 acres) 

(the later being an escaped prescribed fire) occurred between 1954 and 1985. A decline in livestock grazing, followed by recent removal oflivestock from both refuges has 

increased the potential for large wildfires. Despite a major 

suppression effort, 3,000 ha (7,500 acres) of sagebrush and 

mountain-mahogany burned on Badger Mountain in 1994. 

Walker River Watershed Project 

The samples from the six Jeffrey pine and three pinyon 

pine in the Little Frying Pan area produced a 208-year 

master fire chronology dating from 1687 to 1895. A total of 

51 fire scars formed on the nine trees during this period. At 

least 27 different fire years are represented. Sample trees 

recorded from 1 to 5 fire scars during each of these 27 fire 

years. This suggests that fires burned somewhere within 

the less than 40 ha (100 acre) study area every 8 years. Fire 

USDA Forest Service Proceedings RMRS-P-9. 1999 
scars on five of the six Jeffrey pine samples suggested 

extensive burning in 1857. Extensive burning is also indicated in 1864, 1844, 1801, and 1785 when three trees were 

scarred in each of these years. Fires were particularly 

frequent during the 1840's, 1850's, and 1860's when 17 of 

the 51 scars formed. 

Fire scarred pinyons in the Little Frying Pan area verified fire occurrence, but were not a reliable indicator of fire 

frequency. The three pinyon sampled had been scarred one 

time ea - h, while the six Jeffrey pine carried between 3 and 

12 fire scars each (total 48). This marked contrast in fire 

frequency reflects major differences in fuel loading on sites 

occupied by pinyon compared to those occupied by Jeffrey 

pine. The fire scarred pinyons were able to persist in 

microsites where fuels were sparse, and as a result they 

seldom were exposed to lethal heat. In contrast the Jeffrey 

pine grew on productive microsites that supported fine 

fuels of sufficient volume to carry fire. Moreover, pinyon 

needle litter is not as combustible as the long-needle litter 

of Jeffrey pine. 

Ten of the 14 pinyon collected in the four sample areas 

were over 300 years of age, while three exceeded 400 years. 

Excepting one, these trees recorded only one fire each; this 

demonstrates an extremely low susceptibility to scarring. A 

low susceptibility to scarring was also indicated by the 

length of time since the last fire (range 82-248 years). 

The repeat ofthree photographs taken between 1899-1906 

indicated substantial increases in the density of pinyonjuniper in the Walker River Watershed Project (Gruell 

1997b). However, they are not considered representative of 

pre-European settlement conditions. As suggested by the 

fire history data, the absence of fire for 2 to 4 decades or 

longer had probably allowed an increase in tree cover by the 

turn of the century when the original photos were taken. 

Pre-settlement fire intervals averaging only 8 years in 

the less than 40 ha (100 acre) Little Frying Pan study area 

provide strong evidence that low intensity spreading fires 

ignited by lighting and Indians were a common occurrence 

within the WRWP prior to EuroAmerican settlement. The 

high frequency and apparent' low intensity of these fires 

suggested that they were fueled by abundant perennial 

grass, the remnants of which are present today. Sites 

capable of producing contiguous surface fuels, including 

north slopes, canyon bottoms, and gentle topography were 

particularly susceptible to frequent fire. The relatively 

young age of trees and low incidence of charred wood 

(fragments), the presence of which required burning of 

heavy fuels, provide further evidence offrequent low intensity fires on these sites. Tree establishment would have 

been inhibited since trees less than 50 years old are very 

susceptible to being killed by fire (Young and Evans 1981). 

Infertile shallow soils and rocky sites seldom burned since 

they did not produce sufficient fuel to allow fire spread. 

Thus, the prevailing presettlement fire regime maintained 

a savanna-like landscape composed of groups and single 

trees interspersed by large openings with grass being the 

primary ground cover. 

Judging from the presence of down tree trunks, localized 

stand replacement fires apparently occurred during extreme conditions. These fires appear to have been uncommon, however, because concentrations of down tree trunks 

are lacking in these woodlands. Fire scar records indicate 

USDA Forest Service Proceedings RMRS-P-9. 1999 

that pinyon-juniper woodlands of the WRWP were fire 

maintained until the beginning of EuroAmerican settlement. Soon afterwards fire became infrequent, probably 

due to removal of light fuels by livestock, and later by 

aggressive fire suppression. 

By the 1930's, fire suppression strategy placed emphasis 

on aggressive attack of all fires. Since 1960, 266 wildfires 

have been suppressed in the Walker River Watershed 

Project area. Ninety percent of these fires have been held 

under one-quarter acre. Only five of these have been over 

40 ha (100 acres). The largest, 360 ha (900 acres), occurred 

in 1996. 

Modern Fire in the Great Basin 

USDA Forest Service, Intermountain Region fire reports 

covering Nevada, Utah, southern Idaho and western 

Wyoming show an apparent trend. During the 58 year 

period 1930-1978 there were two years when 40,000 ha 

(100,000 acres) or more burned in the Intermountain 

Region. In contrast, in 9 of the past 18 years 100,000 or 

more acres burn in the Intermountain Region. In 1988 and 

again in 1994 over 200,000 ha (500,000 acres) burned. 

Although these data reflect a wide range offuel types, they 

show a significant increase in the occurrence of wildfire in 

the Intermountain Region over the past 76 years. 

Fire reports at the Boise Interagency Fire Center, show 

that many Intermountain Region wildfires have occurred 

in pinyon-juniper woodlands. In the 15 year period 1970-

1985 suppression action was taken on 1,744 of these fires. 

Twenty-eight reached 40 ha (100 acres) or more. The largest of these was 14,000 ha (35,000 acres). The fire report 

record for the 1986-96 fire seasons is incomplete. This was 

a period of many high intensity wildfires. In 1995 and 1996 

alone, 24 fires reached or exceeded 40 ha (100 acres). Some 

of these were between 2,000 ha (5,000 acres) and 6,400 ha 

(16,000 acres). Fire reports covering suppression actions in 

a larger area of pinyon-juniper woodlands administered 

by USDI Bureau of Land Management (BLM) were not 

available. Wildfire occurrence on BLM lands has paralleled 

that on lands administered by the Forest Service. Over 

100,000 ha (250,000 acres) burned in western Utah in 1996. 

A majority of these lands are administered by the BLM and 

include considerable acreage in pinyon and juniper. 

Management Implications 

The results of fire history studies summarized in this 

paper suggest that in the presettlement era, fires were 

common in pinyon-juniper woodlands of the Great Basin. 

Fire frequency varied greatly because of marked differences in fuel continuity. Fire scar evidence suggests that 

fire was frequent on soils that supported sufficient fuels to 

allow fire spread. It was infrequent and did not readily 

spread on thin soils or rocky sites where fuels were sparse 

or absent. Considering these variables, it appears that fire 

burned in irregular patterns, producing a mosaic of burned 

and unburned landscape. This fire regime was severely 

altered by EuroAmericans. Many decades of heavy livestock grazing and fire suppression in the Great Basin 

allowed an enormous increase in density and crown cover of 

27 
pinyon-juniper (Christensen and Johnson 1964; Cottam 

and Stewart 1940; Eddleman and Jaind11994; Tausch and 

others 1981; West 1984). Buildup of woody fuels and increase in fine fuels coincident with marked reductions in 

livestock grazing has resulted in a shift from low intensity 

fires to high intensity fires. Considering the enormity of 

fuel buildup, it is evident that high intensity wildfires will 

continue and perhaps increase. This presents a major 

resource management challenge. 

Fire has played a major role in the ecology of pinyonjuniper woodlands. The challenge facing society is one of 

deciding whether to treat fire as an essential disturbance 

agent or as a destructive force that should be suppressed. 

The ultimate outcome will be decided on the reliability of 

information that reaches the public. It is likely that a 

knowledgeable public would support a program that emphasizes fuel reduction by harvesting excess trees and 

application of prescribed fire in priority areas. Considering 

long-term costs and resource values, it is abundantly evident that this would be highly beneficial to future generations, both environmentally and economically. 

Acknowledgments 

The author thanks Dr. Lee Eddleman, Ray Jaindl, Bill 

Pyle, Blythe Brown, Bill Bryant and Stu Volkland for their 

logistical support during the course of these studies. Critical reviews and helpful suggestions by Dr. Steven Arno, Ed 

Smith, and Bill Pyle improved the structure and organization of this manuscript. 

References __________________ __ 

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in coniferous forests in the Mountain West. Gen. Tech. Rep. INT42. Ogden, Utah: U.S. Department of Agriculture, Forest Service, 

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of Arizona: effects of grazing, fire, and tree control. United 

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Richfield, Utah. 24 p. 

Christensen, E. M.; Johnson H. B. 1964. Presettlement vegetation 

and vegetation change in three valleys in central Utah. Provo, 

UT: Brigham Young University Science Bulletin, Biology Series. Vol. 4, No.4. 16 p. 

Cooper, C. F. 1961. The ecology of fire. Scientific American. 204: 

150-156. 

Cottam, W. P.; Stewart G. 1940. Plant succession as a result of 

grazing and of meadow desiccation by erosion since settlement 

in 1862. Journal of Forestry. 38: 613-626. 

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vegetation analysis. U.S. Department oflnterior, National Park 

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R W. technical coordinators. Proceedings-symposium and 

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Experiment Station: 68-74. 

Gruell, G. E. 1995. Historic role of fire on Hart Mountain National 

Antelope Refuge, Oregon, and Sheldon National Wildlife Refuge, Nevada. A report submitted to U.S. Department ofInterior 

Fish and Wildlife Service, Lakeview, Oregon. 58 p. 

Gruell, G. E. 1997a. Influence of fire on Great Basin wildlife 

habitats. 1996 Transactions of the Western Section of the 

Wildlife Society. 32: 55-61. 

Gruell, G. E. 1997b. Historical role of fire in pinyon-juniper 

woodlands. Walker River Watershed Project: A report submitted to U.S. Department of Agriculture , Forest Service, HumboldtToiyabe National Forest, Bridgeport Ranger District, Bridgeport, California. 20 p. 

Gruell, G. E.; Eddleman, L. E.; Jaindl, R 1994. Fire history of the 

pinyon-juniper woodlands of Great Basin National Park. U.S. 

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Experiment Station: 75-80. 

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grasslands 1835-1890. Ph. D. thesis documentary in historical 

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501-505. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Seed Dispersal and Seedling Establishment 

of Pinon and Juniper Species within the 

Pinon-Juniper Woodland 

Jeanne C. Chambers 

Eugene W. Schupp 

Stephen B. Vander Wall 

Abstract-Understanding the prehistoric and historic dynamics of 

pinon-juniper woodland requires knowledge of the seed dispersal 

mechanisms and seedling establishment requirements of the tree 

species. Here, the types and effectiven-ess of the different seed 

dispersers and the environmental requirements for seedling establishment are compared and contrasted for the various pinon and 

juniper species within the woodlands. The importance of longdistance vs. short-distance dispersal and the roles of ecotones and 

disturbance in woodland dynamics are discussed. Recommendations for future research are given. 

The distribution of pinon and juniper species within the 

woodlands has undergone dramatic changes in both prehistoric and historic times. Since the end of the Wisconsin Ice 

Age 12,000 years ago, some species have moved upward in 

elevation as much as 1,000 to 1,500 m and northwards as 

much as 6° latitude. For example, singleleafpinon (P. monophylla) has migrated from the warm deserts of southern 

Arizona and New Mexico and northern Mexico northwards 

through the Great Basin as far as southern Idaho. Colorado 

pinon (P. edulis) has migrated over most of the Colorado 

Plateau and southern Rockies (Betancourt 1987). Recent 

expansions of the woodlands appear to be influenced by 

human activities. Prior to settlement ofthe West in the early 

1800's, fires burned through much ofthe woodlands as often 

as every 50 to 100 years, resulting in a mosaic of early seral 

grasses, mid-seral shrublands, and late seral woodlands 

(West and Van Pelt 1987). However, overgrazing by livestock and a severe reduction in fire frequency has resulted in 

an increase in relatively unpalatable and fire-intolerant 

shrub and tree species throughout the woodland (West and 

Van Pelt 1987; Miller and others 1994). Trees are expanding 

into adjacent grasslands and shrub lands throughout their 

range (Johnsen 1962; Tausch and others 1981; Miller and 

Rose 1995), and tree density is increasing within existing 

stands (Tausch and others 1981). 

Information on seed and seedling ecology of the tree 

species is essential for understanding both the long- and 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Jeanne C. Chambers is Research Ecologist, USDA Forest Service, Rocky 

Mountain Research Station, 920 Valley Road, Reno, NV 89512. Eugene W. 

Schupp is an Assistant Professor of PI ant Ecology, Department of Rangeland 

Resources, Utah State University, Logan, UT 84322. Stephen B. Vander Wall 

is an Assistant Professor of Biology, Department of Biology, University of 

Nevada, Reno, NV 89512. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

short-term dynamics of pinon-juniper woodlands. Despite 

the fact that seed dispersal and seedling establishment 

processes are critical determinants of both the prehistoric 

migration and historic expansion of the woodlands, relatively little research has focused on this area. Here, we 

provide an overview of the state of our knowledge of seed 

dispersal and seedling establishment of pinon and juniper 

species within the woodlands. We then discuss the importance of long-distance versus short-distance dispersal and 

the roles of ecotones and disturbance in woodland expansion. Finally, we suggest areas for future research. 

Seed Dispersal Processes ___ _ 

To understand plant dispersal processes, information on 

both the types and behaviors of the seed dispersers and the 

effectiveness of dispersal for plant establishment is necessary. Disperser effectiveness has been defined as "the contribution a disperser makes to the future reproduction of a 

plant" population (Schupp 1993). Effectiveness has a quantitative component (the number of seeds dispersed) and a 

qualitative component (the likelihood that a dispersed seed 

will survive to produce a new plant in the population). Here, 

we examine the information on both the types and behaviors 

of the animals that disperse pinon and juniper and the 

effectiveness of those dispersers. 

Seed dispersal of both pinon and juniper is probably much 

more complex than the literature to date indicates. We have 

the best information on seed dispersal of pinon pines by 

birds. Pinon pines are dispersed by several species of corvids 

(jays and nutcrackers) that store seeds in shallow caches in 

the soil (Vander Wall and Balda 1981; Vander Wall 1990). 

Pinon pine cones and seeds are well adapted for dispersal by 

birds. The seeds are large and nutritious (Botkin and Shires 

1948), and the cones are weakly constructed so that the 

seeds can be easily extracted by corvids with long pointed 

beaks, such as Clark's nutcracker (Nucifraga columbiana) 

and pinon jays (Gymnorhinus cyanocephalus). Seeds are 

enclosed in deep pockets and held by thin flanges so that they 

do not fall readily from the cones. Unlike many conifers, 

cones are primarily pointed to the side and upward, which 

not only retards seed loss, but increases the visibility and 

availability of the seeds to avian dispersers. 

Birds typically disperse seeds from several meters to 5 km 

(Vander Wall and Balda 1981). Differences in dispersal 

distances exist among different bird species with the more 

solitary scrub jays (Aphelocoma coerulescens) seldom 

dispersing seeds more than 1 km, the gregarious pinonjays 

29 
carrying seeds slightly farther, and Clark's nutcrackers 

carrying seeds as far as 22 km. Whilejays typically place one 

seed in each cache site, nutcrackers cache from one to 10 

seeds with a mean of about four seeds per cache. The total 

number of seeds cached can be phenomenal. Individual 

Clark's nutcrackers scatter hoard between 22,000 to 33,000 

Colorado pinon seeds (Vander Wall and Balda 1977) or 

17,900 singleleaf pinon seeds (Vander Wall 1988) in a good 

seed crop year. Ligon (1978) estimated that a flock of 250 

pinon jays could cache about 4.5 million Colorado pinon 

seeds over 5 months. 

Seed caching by corvids has important consequences for 

the fates of pinon pine seeds. It can be quantitatively 

effective for pinon pine as large numbers of seeds are cached 

and, especially in large seed crop years, many are left 

unrecovered to germinate and possibly establish. Some 

aspects of bird dispersal are qualitatively effective while 

others are not. Pinons almost always require burial for 

establishment, and birds bury the seeds 2 to 4 cm in the soil 

(Vander Wall, personal observation). However, pinons also 

have a fairly strict nurse plant and shading requirement, 

and birds tend to place most seeds in interspace environments, not in more favorable microhabitats under trees or 

shrubs (Vander Wall, personal observation). 

The importance of seed caching of pinon pine by rodents 

has been largely ignored and probably vastly underestimated. Most rodents, unlike the corvids, forage for seeds on 

the ground after the seeds have fallen from the tree. In the 

Pine Nut Range of Nevada, deer mice (Peromyscus maniculatus), pinon mice (Peromyscus truei), Great Basin pocket 

mice (Perognathus parvus), and Panamint kangaroo rats 

(Dipodomys panamintinus) all scatter hoard singleleaf pinon 

seeds (Vander Wall 1997). Of 1,000 labeled seeds placed 

under five source trees, 69 percent were taken by rodents 

and 24 percent were scatter hoarded 5 to 30 mm deep. 

Rodents placed 36 percent of these scattered caches under 

shrubs, 39 percent in the open and the rest (25 percent) at the 

edge of shrub canopies. At other locations chipmunks, such 

as cliff chipmunk (Tamias dorsalis) and Panamint chipmunk (T. panamintinus), are probably important dispersers 

of pinon seeds. Rodents are qualitatively effective seed 

dispersers in that they bury the seeds and place most of them 

(about 60 percent) under or adjacent to shrubs. However, 

many of the seeds that are harvested are placed in larders 

where they have little or no chance of establishment (Vander 

Wall 1990). From a quantitative perspective, they may be 

less important because, except in heavy seed crop years, 

most seeds do not fall to the ground before they are harvested 

by birds. 

Relatively little is known about dispersal of juniper species within the woodland. In general, most species of juniper 

have been assumed to be bird dispersed. Unlike bird dispersal of pinon in which the seeds are scatter hoarded, bird 

dispersal of junipers is by frugivory in which the seeds are 

ingested and passed through the gut track. Many bird 

species are involved injuniper dispersal. At least 12 species 

of birds feed on fruits and potentially disperse seeds of 

westernj uni per (J. occidental is) (Maser and Gashwiler 1978), 

13 species are known to disperse Ashe juniper (J. ashei) 

(Chavez-Ramirez and Slack 1994), and 52 species have been 

observed feeding on eastern red-cedar (J. virginiana) 

(Van Dersal 1938). Of the wide diversity of bird species 

30 

involved, the most important for juniper dispersal are probably members ofthe highly frugivorous subfamily Turdinae 

(Muscicapidae) such as bluebirds (Sialia mexicana and S. 

currucoides), Townsend's solitaire (Myadestes townsendi), 

and American robin (Turdus migratorius), and two members of the family Bombycillidae, the waxwings Bombycilla 

garrulus and B. cedrorum (Gabrielson and Jewett 1940; 

Salomonson 1978; Holthuijzen and Sharik 1985; ChavezRamirez and Slack 1994). The rounded and more or less 

fleshy cones of junipers are well suited for frugivorous 

dispersal, especially by birds (Salomonson and Balda 1977; 

Salomonson 1978). 

Fruits are conspicuously colored blue or reddish and are 

easily accessible on the outer layers ofthe foliage. The fleshy 

portion of a one-seed juniper (J. monosperma) cone has an 

energy content of 1.32 kJ making it a reasonably rich energy 

source. Also, the thick hard seed coat allows seeds to pass 

undamaged through the guts of most birds and mammals. 

Dispersal distances and patterns vary depending on the bird 

species and the juniper species (Holthuijzen and Sharik 

1985; Chavez-Ramirez and Slack 1994). The effectiveness of 

birds as dispersal agents varies among species of junipers. 

For species such as western juniper, birds appear to disperse 

the majority of the seeds and, thus, are quantitatively 

important. Bird dispersal is often qualitatively effective as 

most birds deposit seeds primarily in more favorable under 

shrub or tree microhabitats and only occasionally carry 

seeds to open microsites. Also, seeds tend to be deposited 

singly or in small groups and, thus, may be less likely to die 

from density-dependent seed predation or competition 

(Chavez-Ramirez and Slack 1993; Schupp 1993). However, 

some bird species, such as cedar waxwings, travel in flocks 

and use the same perches repeatedly resulting in high seed 

densities under single trees. Another limitation of bird 

dispersal is that seeds are deposited on the soil surface and 

are dependent on other mechanisms of burial. 

Mammals, considered to be unimportant dispersers of 

juniper seeds in the past, may be quite important for certain 

juniper species. Mammals that consume and disperse juniper seeds include woodrats (Neotoma spp.), Virginia opossum (Didelphis virginiana), Nuttalls cottontail (Sylvilagus 

nuftallii), desert cottontail (S. auduboni), black-tailed jackrabbit (Lepus californicus), coyote (Canis latrans), red fox 

(Vulpes vulpes), gray fox (Urocyon cinereoargenteus), black 

bear (Ursus americanus), ringtail (Bassariscus astutus), 

racoon (Procyon lotor), mule deer (Odocoileus hemionus), 

white-tailed deer (0. virginianus), and assorted livestock 

(Miller 1921; Parker 1945; Martin and others 1951; Johnsen 

1962; Maser and Gashwiler 1978; Salomonson 1978; ChavezRamirez and Slack 1993; Willson 1993; Schupp and others 

1997a, b). All species pass at least some seeds intact and, in 

some cases, seed germination is increased (Miller 1921; 

Johnsen 1962; Schupp and others 1997a). 

Mammals may be quantitatively more important for some 

species of juniper than others. Western juniper is dispersed 

by several different bird species, but coyotes appear to be one 

of the few important mammalian dispersers (Schupp and 

others 1997b). In contrast, Utah juniper (J. osteosperma) 

appears to be dispersed primarily by cottontail rabbits and 

jackrabbits, and less so by birds (Schupp and others 1996; 

1997a). This would seem to indicate that for the fleshier, 

moister species of junipers, coyotes and, perhaps in some 

USDA Forest Service Proceedings RMRS-P-9. 1999 
species, foxes are the major mammalian dispersers. These 

are also the species fed on mostly by birds. In contrast, the 

woodier, drier juniper species may be dispersed largely by 

rabbits. In general, mammalian endozoochorous dispersal 

may not be effective for plant establishment. Seeds are 

deposited on the soil surface, often in high densities, and 

usually in the open and not in more favorable shaded 

environments. One advantage of mammalian seed dispersal 

is that passage through the gut track can be relatively slow 

resulting in long transport distances. 

As for pifion pines, the role of scatter hoarding rodents in 

the dispersal of juniper has probably been greatly underestimated. Rodents commonly cache tree seeds (Vander Wall 

1990; 1997), and clumps of juniper seedlings have been 

observed emerging from caches in the spring (Vander Wall 

1990; Schupp unpublished data). In west-central Utah, a 

minimum of 16 to 33 percent of all natural Utah juniper 

recruits less than or equal to 2.0 m tall emerged from rodent 

caches. To quantify the role of rodents in the dispersal of 

Utah juniper, 500 labeled seeds were placed under four 

different source trees in the Pine Nut Range, Nevada, and 

seed fates were monitored (Vander Wall unpublished data). 

Slightly less than half of the seeds were taken (41 percent) 

and of those 27 percent were found in caches. Although a 

relatively low percentage of seeds were cached, the study 

was conducted in mid-summer when other, possibly more 

desirable shrub and forb seeds were available. 

In general, the low preference for juniper seeds may result 

in low recovery of cached juniper seeds and, thus, a high 

potential for seed germination and establishment. Also, 

many juniper seeds are available under the trees on a yeararound basis potentially resulting in more caching activity 

than this single study indicates. As described for pifion pine, 

seed caching by rodents may be highly effective in that many 

of the seeds are placed in favorable environments and have 

a high potential for establishment. 

Seedling Establishment 

Processes 

Both the seed characteristics and the types ofmicrohabitats in which seeds are placed are important in determining 

seed fates after dispersal. In general, pifion pines have 

short-lived seeds with little innate dormancy (Meewig and 

Bassett 1983). Thus, they form only a temporary seed bank 

with most seeds germinating the spring following dispersal. 

Density of seeds in the seed bank is highly dependent on the 

current year's cone crop. Pifion pines exhibit regionwide 

synchrony in cone production with singleleafpifion masting 

every 2 to 3 years and Colorado pifion every 5 to 7 years 

(Tueller and Clark 1975). The potential for a large temporary seed bank is high during mast years, especially since 

many seeds probably remain unrecovered by animals. During nonmast years, the seed bank is probably quite sparse. 

For pifion, germination and establishment are most likely 

when favorable growing season conditions follow a mast 

year. 

In contrast to pifion pines, junipers often have long-lived 

seeds. Tests of stored juniper seeds showed that 45-year old 

Utah juniper still had 17 percent germination, 21-year-old 

one-seedjuni per had 54 percent germination, and 9-year-old 

USDA Forest Service Proceedings RMRS-P-9. 1999 

alligator juniper (J. deppeana) had 16 percent germination 

(Johnsen 1959). The long-lived seeds are often highly dormant with germination being delayed by impermeable seed 

coats, immature embryos, embryo dormancy, or the presence of inhibitors (Fisher and others 1987). Consequently, 

junipers have highly persistent seed banks with germination of a single seed cohort extending over many years. 

Although seed production is highly variable among both 

individuals and years, junipers exhibit less pronounced 

masting than pifion. The result is a more or less continuous 

input of seeds into the seed bank. For juniper, germination 

and establishment can occur whenever favorable environmental conditions exist. 

A common assumption concerning the establishment of 

pifion and juniper is that they require a nurse plant for 

establishment. However, there is little establishment data 

that directly follows the fates ofpifion or juniper seedlings. 

Most establishment studies have examined the locations of 

seedlings in communities with varying tree and shrub cover 

without considering the pattern or effectiveness of dispersal 

or the requirements for establishment. Usually, higher 

numbers of pifion and juniper seedlings are found under 

shrubs or adult trees than in interspace environments 

(Johnsen 1962; Burkhardt and Tisdale 1976; Everett and 

others 1986a.; Eddleman 1987; Callaway and others 1996). 

In fully stocked stands of one-seed juniper, singleleafpifion, 

and western juniper, higher number of seedlings occur 

under trees than in interspace environments (Johnsen 1962; 

Everett and others 1986a; Miller and Rose 1995). However, 

in areas where western j uniper is expanding into sagebrush 

communities, higher numbers of seedlings occur under sagebrush (52 to 65 percent) than under trees (17 to 31 percent). 

A more detailed examination reveals large differences in 

the nurse plant requirement both among and within species. 

Pifion seedlings rarely establish in inters paces or open 

environments (Everett and others 1986a; Callaway and 

others 1996). This is well illustrated by the total lack offirstyear survival of singleleaf pifion seedlings in interspace 

microhabitats in the Pine Nut Range, Nevada (Chambers 

unpublished data). In contrast, juniper seedlings are capable of establishing in these environmen ts under the proper 

conditions. First-year survival of Utah juniper seedlings in 

the Pine Nut Range in interspace microhabitats was less 

than in undertree sites, but was as high or higher than in 

under sagebrush sites (Chambers unpublished data). In 

Tintic Valley, Utah, emergence of Utah juniper seedlings 

differed among open, shrub, and tree microhabitats and also 

among years (Schupp and Gomez, unpublished data). The 

undershrub microhabitat had the highest emergence in one 

year, the lowest in a second, and was intermediate in two 

other years. Survival differed for only one emergence year, 

being least under shrubs and highest under trees. In expanding western juniper populations, 18 to 47 percent of 

established seedlings occurred in interspaces (Burkhardt 

and Tisdale 1976; Miller and Rose 1995). For Utah juniper 

on stabilized Lake Bonneville sand dunes in Utah, most of 

the few natural seedlings occurred in interspaces (Schupp 

unpublished data). Also, in the Southwestern grasslands 

and shrublands, juniper seedlings readily establish in open 

environments (Johnsen 1962; Salomonsen 1978). Differences between pifion andjuniper in the nurse plant requirement may be related to their physiological characteristics. 

31 
J uni per species have greater drought tolerance and a higher 

capacity to obtain water resources for interspace microhabitats and shallow soils (Nowak and others, proceedings). This 

may enable seedlings to establish in unshaded inters paces 

with higher soil temperatures. 

Higher establishment of juniper in open or interspace 

environments in the southwestern portion of the woodlands 

may be due to differences in precipitation patterns. While 

much of the Great Basin and more northern areas receive 

most precipitation during winter, the southwestern grasslands and shrublands receive moderate winter precipitation 

and monsoonal summer rains. Summer precipitation in the 

Southwest may offset the beneficial microenvironmental 

effects of nurse plants for seedling establishment in the 

Great Basin and more northern areas. 

In those ecosystems with little summer rainfall, undertree 

and shrub microhabitats appear to p~ovide favorable conditions for establishment of both pinon and juniper. Many 

environmental characteristics under trees and shrubs are 

more favorable for seedling establishment than those in 

inters paces. Shrubs and trees in arid or savanna ecosystems 

have been described as "islands of fertility." The microhabitats under both shrubs and trees often have higher concentrations of limiting nutrients, higher organic matter and 

total nitrogen, lower bulk densities, higher infiltration and 

soil water holding capacities, and higher rates of nutrient 

cycling (Everett and others 1986b; Doescher and others 

1987; Klopatek 1987). They are also characterized by lower 

irradiance and soil temperatures (Stark 1994) - microenvironmental conditions favorable for many conifers. Although 

these areas receive less effective precipitation than interspace areas, they experience higher relative humidity and 

delayed dry down relative to open areas and grasslands 

(Johnsen 1962; Vetaas 1992; Stark 1994). 

Although nurse plants facilitate seedling establishment, 

they also compete for available resources. Lowered seedling 

growth rates may be a tradeoff for favorable microenvironmental conditions beneath nurse plants. Pinon and juniper 

seedlings exhibit higher seedling survival under artificial 

shading (Meagher 1943), but seedlings in full sun have 

higher growth rates than those beneath shrubs (Burkhardt 

and Tisdale 1976; Miller and Rose 1995; Callaway and 

others 1996). Favorable water relations may also increase 

seedling survival underneath adult trees or nurse plants. 

Seedlings of western juniper have tighter stomatal control 

over water use than adult trees and are more responsive to 

environmental changes (Miller and others 1992). Singleleaf 

pinon seedlings associated with sagebrush exhibit reduced 

stomatal conductance as the summer progresses, while 

sagebrush water use continues to increase reaching levels 

up to five times greater (per unit leaf area) than associated 

pinon (Drivas and Everett 1988). 

The effects of competition from grasses and other herbaceous vegetation on pinon and juniper seedling establishment are not clear because ofthe lack of experimental data. 

It appears that competition from annual forbs and grasses 

can red uce the seedling survival ofU tahj uni per and singleleaf 

pinon during the first year after emergence (Chambers, 

personal observation). Also, competition from established 

grasses red uces the ini tial establishment of one-seedj uni per 

(Salomonson 1978). However, once seedlings are established 

(that is, greater than 1 or 2 years old) competition appears 

32 

to have little effect on subsequent survival. In western 

Oregon, westernjuniper seedlings were capable of establishing into the community regardless of grass cover or range 

condition (Miller and others 1994) 

Short-Distance Versus 

Long-Distance Dispersal 

Highly effective seed dispersal and seedling establishment processes have been key elements in both the longdistance migration and local expansion of pinon and juniper 

species within the woodlands. Recently, it has been suggested that local population growth, short-distance dispersal, and long-distance migration are all interdependent 

(Clark and others 1998). Although rapid migration is driven 

by occasional, long-distance dispersal events, the likelihood 

of such long-distance events occurring increases with seed 

availability at the existing front. The greater the local population growth and the greater the seed production, the higher 

the probability that some seeds will be dispersed long distances. Thus, it is important to consider both the local component of seed dispersal that is responsible for local population 

growth and expansion, and the long-distance component of 

seed dispersal that is responsible for species migration. 

In pinon and juniper, different classes of dispersers are 

responsible for local versus long-distance dispersal. In pinon, 

relatively short-range dispersal is accomplished largely by 

rodents, scrub jays, Mexicanjays, and pinon jays that often 

or always cache seeds within a few hundred meters of the 

source tree (Vander Wall and Balda 1981; Vander Wall 

1997). Unrecovered caches produce new recruits, resulting 

in population growth and local range expansion. Relatively 

long-range dispersal is achieved by birds that often carry 

seeds long distances to new habitats. These birds include 

nutcrackers, pinon jays, and Steller's jays. Seed dispersal 

out of the pinon-juniper woodland introduces the species to 

habitats that mayor may not be suitable for establishment. 

Ifsuitable, the cached seeds can establish a founding colony 

from which a new stand may eventually arise. 

The two extreme spatial scales of dispersal are not as 

obvious for juniper as for pinon. Depending on the juniper 

species, local dispersal within stands leading to seedling 

recruitment is probably due to birds, lagomorphs, and scatter hoarding rodents. Most birds have short gut-retention 

times and, thus, dispersal is probably within or near the 

woodland. Birds frequently fly only short distances to perches 

where they sit and process fruit before returning to the same 

tree or moving to a nearby fruit source (Schupp 1993). 

Although rodents and lagomorphs are capable of moving 

seeds hundreds of meters, they probably cache or deposit 

most seeds within or near the woodland (Schupp and others 

1997b). Long-distance dispersal of junipers is likely by birds 

and large frugivorous mammals. Although most seed dispersal by birds is probably local, some seeds are potentially 

dispersed longer distances by flocks of robins, bluebirds, and 

waxwings, which are widely ranging in fall and winter 

(Gabrielson and Jewett 1940). Large frugivorous mammals 

are likely candidates for long-distance dispersal because 

they have long gut-retention times and can travel long 

distances over diverse terrain (Willson 1993; Clark and 

others 1998). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Role of Ecotones ------------------------

Ecotones between woodlands and adjacent shrublands 

and grasslands frequently provide favorable microhabitats 

for seedling establishment and are often particularly active 

zones of seed dispersal. Because shrubs provide favorable 

establishment microhabitats, expansion into shrublands 

along ecotones or transitional areas is common. Most juniper 

and pinon seedlings occur under shrubs and, as trees mature, they over-top the shrubs and the shrubs die. In southwestern grasslands, grasses may inhibit initial seedling 

establishment, but once established seedlings experience 

little competition. In contrast, in fully stocked stands most 

seedlings establish under adult trees forming "seedling 

banks" with little chance of maturing unless the adult tree 

is removed or dies. 

Ecotones are often used by animal dispersers that occur 

exclusively in one area or the other as well as by those that 

occur in both areas. Following fire in pinon and juniper 

woodlands in Nevada, ecotonal areas had the highest rodent 

species diversity (richness), were actively used by frugivorous mammals, and had the highest bird use (Mason 1981). 

Even rodent species such as pinon mice that depend on the 

presence of trees and species such as Great Basin pocket 

mice and chipmunks (such as, Tamias spp.) that prefer some 

tree or shrub cover use ecotones once vegetation has established. Species such as deer mice that prefer more open 

habitats occur in both the woodlands and ecotonal areas. 

Frugivorous mammals frequently forage 100s of meters out 

of the woodland, and lagomorphs are known to deposit seeds 

in grasslands up to 1.6 km from the nearest woodland 

(Schupp and others 1997b). Important avian dispersers of 

pinon, such as the corvids, depend on the woodlands, but 

utilize the ecotonal areas (Mason 1981). Because avian 

dispersers of juniper, such as the Turdinae and waxwings, 

are more likely to use larger trees or snags as perches, they 

may be more important for dispersal within the woodlands 

or after disturbances that leave some trees in place. 

Importance of Disturbance ___ _ 

In pinon-juniper woodlands, as in other ecosystems, characteristics of the disturbance and life history attributes of 

the species determine establishment probabilities of seeds 

and seedlings. Most tree seedlings are killed by fire, but 

seeds of both pinon and juniper, especially those that are 

cached, have a reasonable probability of survival depending 

on cache microhabitat. Undershrub and tree microhabitats 

often experience higher soil temperatures than interspace 

areas, especially ifthe entire shrub or tree and the duffburn 

(Wells and others 1979) and would be expected to exhibit the 

highest seed mortality after fires. 

Mechanical disturbances such as chaining have a much 

different effect on seed and seedling fates than fires. Tree 

seedlings frequently survive mechanical disturbances, and 

because a significant "seedling bank" can exist under mature trees, they can be released from competition after 

overstory removal. Seeds that have already arrived on the 

soil surface are left in place, although redistribution or 

burial may occur due to the equipment. Establishment 

USDA Forest Service Proceedings RMRS-P-9. 1999 

probabilities depend on the characteristics of the microhabitats after treatment. If downed trees and understory 

shrubs are left in place, more shaded microhabitats and 

nurse plants for seedling establishment will be available. If 

trees are piled and burned and understory shrubs are 

removed, fewer desirable microhabitats for seedling establishment will remain. 

Disturbances that remove both trees and understory shrubs 

in pinon-juniper woodlands have a relatively greater effect 

on the establishment of pinon than juniper. Because pinons 

have short-lived seeds and a nurse plant requirement, pifion 

seeds and seedlings that survive the disturbance have a 

minimal chance of survival. In contrast, because junipers 

have long-lived seeds and less strict nurse plant requirements, their seeds and seedlings have a higher probability of 

establishment. Also, pinon seedlings appear to be less tolerant of competition from grasses and other herbaceous vegetation thanjuniper seedlings (Burkhardt and Tisdale 1976; 

Miller and Rose 1994). Consequently, initial establishment 

of juniper seedlings is frequently higher than that ofpifion 

seedlings following disturbance in the singleleaf pinonwestern juniper woodland (Tausch and others 1981) and 

probably other woodland types. 

Future Research 

Several areas relating to the seed dispersal and seedling 

establishment of pinon and juniper require additional research if we are to understand the dynamics of the woodlands. We need more information on: (1) types and behaviors 

of rodent dispersers of pinon and of all dispersers of juniper; 

(2) effectiveness of different types of animal dispersers for 

seedling establishment; (3) environmental requirements for 

seedling establishment; and (4) the differences in seed dispersal and seedling establishment among species and regions. Ecotones appear to be particularly promising for 

increasing our understanding of ecosystem disturbance and 

woodland dynamics. 

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Parker,K. W.1945.Junipercomes to the grasslands. Why it invades 

southwestern grassland; suggestions and control. American Cattle 

Producer 27 (November): 12-14,30-31. 

Salomonson, M. G. 1978. Adaptations for animal dispersal of oneseed juniper seeds. Oecologia. 32: 333-339. 

Salomonson, M. G.; Balda, R P. 1977.Winter territoriality of 

Townsend's solitaires (Myadestes townsendi) in a pinon-juniperponderosa pine ecotone. Condor. 79: 148-16l. 

Schupp, E. W. 1993. Quantity, quality and the effectiveness of seed 

dispersal by animals. Vegetatio. 107/108: 15-29. 

Schupp, E. W.; Fuentes, W.; Gomez, J. M. 1996. Dispersal of Utah 

juniper (Juniperus osteosperma) seeds by lagomorphs. In: West, 

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Conress, Vol. 1. Denver, CO: Society for Range Management: 

496-497. 

Schupp, E.W.; Gomez, J. M.; Jimenez, J. E.; Fuentes, J. 1997a. 

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frugivorous mammals on Juniper Mountain, southeastern 

Oregon. Great Basin Naturalist. 57: 74-78. 

Schupp, E. W.; Heaton, H. J.; Gomez, J. M. 1997b. Lagomorphs and 

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Press: 255-284. 

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G. F.; Busby, F. E., eds. The Pinyon-Juniper Ecosystem: a Symposium. Logan, UT: Utah State University: 27-39. 

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Vander Wall, S B. 1997. Dispersal of singleleaf pinon pine (Pinus 

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181-191. 

Vander Wall, S. B.; Balda, R P. 1977. Coadaptation of the Clark's 

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USDA Forest Service Proceedings RMRS-P-9. 1999 
Ecophysiological Patterns of Pinyon 

and Juniper 

Robert S. Nowak 

Darrin J. Moore 

Robin J. Tausch 

Abstract-Although species that dominate over 30 million ha may 

be expected to have aggressive ecophysiological traits, pinyon and 

juniper generally are conservative in their acquisition and use of 

resources when measured on a per gram offoliage basis. Assimilation rates of pinyon and especially of juniper are very uniform over 

different types and scales of environm~ntal gradients. Although 

pinyon and juniper often intermix, some subtle ecophysiological 

differences exist between the two genera that appear to influence 

plant distribution. These conservative ecophysiological traits help 

pinyon and juniper dominate the landscape in two ways: first, they 

allow the conifers to support a much greater amount of foliage 

biomass than co-occurring shrubs, given the same amount of resources; and second, when coupled with distinct ecophysiological 

differences betweenjuvenile and adult plants, they help pinyon and 

juniper establish under, then tolerate, and ultimately outsize and 

outlive their shrub-steppe nurse plants. 

Pinyon-juniper woodland are a major vegetation assemblage in southwestern North America. Pinyon and juniper 

occur on approximately 30 million ha (West, this volume), 

which is a 50 percent increase from estimates near 20 million 

ha in 1986 (Buckman and Wolters 1987). Three of the more 

common juniper species are one-seed juniper (Juniperus 

monosperma), western juniper (J. occidentalis), and Utah 

juniper (J. osteosperma), and two of the more common 

pinyon species are pinyon pine (Pinus edulis) and singleleaf 

pinyon (P. monophylla). Although many parts of this woodland type have one species of juniper co-dominant with one 

of pinyon, a single juniper or pinyon species can dominate 

particular sites, to the exclusion of other tree species. 

Invasive species are often thought to have aggressive, 

opportunistic ecophysiological traits such as high photosynthetic rates, high growth rates, and rapid responses to 

changes in resource availability (Bazzaz 1986). For example, 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Robert S. Nowak is Professor of Plant Physiological Ecology and Darrin J. 

Moore was Graduate Research Assistant in the Department of Environmental and Resource Sciences / MS 370, University of Nevada-Reno, Reno, NV 

89557; current title and address for Moore are: Research Technician, University of Georgia Marine Institute, Sapelo Island, GA 31327. Robin J. Tausch is 

Project Leader, USDA Forest Service, Rocky Mountain Research Station, 920 

Valley Road, Reno, NV 89512. Support for this paper came, in part, from the 

U.S. Department of Energy's Program for Ecosystem Research 

(DE-FG03-93ER61668), the USDA Forest Service (including INT-90518-

RJVA), and the Nevada Agricultural Experiment Station. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

two of the most successful invasive exotics in western North 

America are cheatgrass (Bromus tectorum) and saltcedar 

(Tamarix ramosissima). Both species share a number of 

traits that may account for their aggressive invasiveness, 

such as flexibility in life history attributes, ability to germinate over a wide range of environmental conditions, rapid 

growth, and high allocation to root growth during plant 

establishment (Smith and others 1997). 

The primary purpose ofthis paper is to provide a summary 

review of the physiological ecology of pinyons and junipers 

with the ultimate goal to understand how their ecophysiologlcal traits may explain plant distribution, population 

dynamics, and the ability of these species to invade and 

ultimately dominate shrub communities. First, we summarize ecophysiological information about carbon gain and 

water relations of pinyons andjunipers. In many cases, data 

on only one or a limited number of species are available. 

Next, ecophysiological traits of pinyon and juniper will be 

contrasted with each other, then contrasted with another 

major dominant of semiarid lands in the West, sagebrush 

(Artemisia tridentata), to investigate possible sources of tree 

dominance. 

Ecophysiological Traits 

Carbon Gain 

Assimilation Rates-Diurnal changes in assimilation 

rates for western juniper (Miller and others 1992) follow a 

pattern similar to those of other Great Basin plants (Smith 

and Nowak 1990). During spring and early summer when 

soil moisture is plentiful, assimilation rates typically track 

irradiance (Miller and others 1992). Assimilation rate increases during the morning as the sun rises higher into the 

sky, stays near maximum rates for about six hours during 

the middle part of the day, then declines rapidly at the end 

of the day as irradiance decreases. As soil moisture decreases, assimilation rates peak earlier in the day, and a 

large midday depression in assimilation occurs. By the end 

of summer, assimilation often peaks within 2-3 h of sunrise 

and declines to near zero by early afternoon. 

The maximum rate of assimilation that occurs during the 

day does not vary greatly from spring through fall (fig. 1A). 

During winter, maximum assimilation rates are very close 

to zero, which is similar to other Great Basin species such as 

crested and bluebunch wheatgrass (Nowak and Caldwell 

1984). By April, maximum assimilation rates are relatively 

high and decline only slightly until fall, when maximum 

rates decline more rapidly. Presumably, cold air and leaf 

temperatures during fall and winter are the primary reason 

35 
20 

..- • 

'm 15 

'0) 

• (5 10 E 

.s )( 

... 

E 5 

<{ 

0 ..-

-u 

«;"0) 300 

(5 

.. t-! western JUniper ! , 5. 200 

<{ 

>-

1ii 1oo 

Cl 

0 

;- 20 '0) 

0) 15 .s 

Z 

- 10 n:I 

Q) 

-I 5 

J FM A M J J AS 0 N 

Figure 1-(A) Maximum assimilation rate 

during the day; (9) total daily carbon gain; and 

(C) nitrogen content of foliage on different 

dates during the year for western juniper 

(closed symbols, solid lines) and Utah juniper 

(open symbols, dashed lines). Error bars are 

standard errors. Different symbol shapes indicate sources of data: circles are data from 

Miller and others (1992: fig. 3, table 2), triangles are unpublished data of the authors, 

and squares are data from Ehleringer and 

others (1986: fig. 5). Although lines 'are from 

polynomial curve fitting, they are meant primarily as a guide to general trends of data. 

A 

B 

c 

D 

for low maximum rates of assimilation during these time 

periods . 

The total amount of carbon gained during the day follows 

a seasonal pattern similar to that for maximum assimilation 

rates except for an earlier decline in fall (fig. 1B). Daily 

carbon gain is low in winter, relatively high for much of the 

time period from April through August, then declines rapidly during fall. Both water stress and air temperature 

interact to produce this seasonal pattern of carbon gain, but 

the importance of temperature becomes apparent when 

comparisons are made at different elevations. Daily carbon 

gain of western and Utah junipers at low elevations tend to 

be highest earlier in the year and lower in the fall (table 1). 

In contrast at high elevations, daily carbon gain gradually 

increases from spring to its largest value in fall. Relatively 

cooler temperatures at higher elevation appear to decrease 

daily carbon gain in spring relative to that at lower elevation, even though both elevations had adequate soil moisture. However, despite these differences in the temporal 

pattern of when maximum daily carbon gain occurred, the 

average rates over the entire growing season were remarkably similar: 151 )lmol g-l d-1 for plants at low elevation sites 

and 147 )lmol g-l d-1 at high elevation sites. 

The similarity in seasonal carbon gain extends to a regional scale of geography (fig. 2). Based on estimates of 

carbon gain over the entire time period from spring through 

fall, results from six mountain ranges sorted into 2 statistical groups despite large differences in climate: a 

north-northwest group of three ranges (Juniper Mountain, 

Virginia Mountains, and Monitor Range) and a 

south-southeast group of three ranges (Sonora Pass, Snake 

Range, and Spring Mountains). What is especially striking 

about both groups is that both contain one mountain range 

that has western juniper and two ranges that contain Utah 

juniper. Thus, even though climatic influences on carbon 

gain are relatively small, climatic influences appear to be 

more important than taxonomic influences. 

Dependence of Assimilation on Environmental 

Factors-Patterns of assimilation response to irradiance 

and temperature for western juniper (Miller and others 

1995) are similar to those for other Great Basin species 

Table 1-Mean total carbon assimilation (Ilmol g-1 d-1

) over the 10-hour daylight 

period from 8 AM to 6 PM for Utah and western juniper. Measurements were 

made at 2-hour intervals with a LiCor 6200 (Lincoln, NE) under ambient 

conditions for each of 12 trees at a low elevation site and at a high elevation 

site on each of six mountain ranges. Low elevation sites were near the lower 

elevational limit of juniper on the particular range and high elevation sites 

were near the upper elevational limit. Measurements were made on two 

mountain ranges that had western juniper (Juniper Mountain and Sonora 

Pass) and on four ranges that had Utah juniper (Virginia Mountains, Monitor 

Range, Snake Range, and Spring Mountains). 

Elevation Late-May Mid-July Mid-September 

Western juniper 

Low elevation 185 200 103 

High elevation 126 152 154 

Utah juniper 

Low elevation 155 129 152 

High elevation 139 108 199 

36 USDA Forest Service Proceedings RMRS-P-9. 1999 
Bridgeport, CA Sutcliff, NV 

F M A M J J A 5 a N 

30 

25 

'<;" C) 

(5 20 

E b 

E 

~ 15 

iU 

c 

~ 10 

10 

Q) 

en 5 

o f--'-----'--

3 ~ vvestern juniper 

~ 

E 

"0 2 E 

S 

w 

::> 

~1 

!.:.: ... :.:.:.:.:.:.:.:.:., utah juniper 

a Oregon 

a 

Sonora Pass 

California 

Figure 2-Climatic and leaf gas exchange data for six mountain ranges along three cross-basin transects. 

At the top are climate diagrams (sensu Walter and others 1975) for the climate station closest to each 

mountain range. Climate stations are ordered left to right based on increased annual drought severity; 

drought severity is estimated as the difference between the two types of shaded areas in the climate 

diagram. For each climate diagram, one line and left y-axis are mean monthly temperature, the other line 

and right y-axis are precipitation, area shaded with vertical lines represent periods during the year when 

precipitation is sufficient for plants, and solid area represents periods when water deficits occur. The two 

lower-left panels are carbon gain over and daily water use efficiency during the time period from mid-May 

through September. Ranges that include western juniper are indicated by open bars and those with Utah 

juniper are shaded. Ranges are ordered to correspond with their respective climate diagram. Data are 

unpublished data of the authors. Locations of each mountain range (bold text, solid symbols) and climate 

stations (open diamonds) are shown on the map, which also shows all study plot locations for western 

(triangles) and Utah (circles) juniper cross-basin transects of the authors. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Idaho 

IIGreat Basin 

Natl.Pari< 

~I ~~ :.+-16 I 

f:o" 

~ ~'I 

f:o~<¥- ~-

"t!J~ I 

V -) 

~~ " \ <ii'''' " ~ Arizona 

37 
. . 

(Smith and Nowak 1990). For adults trees, assimilation 

rates are saturated at an irradiance level approximately 

equivalent to one-half solar irradiance, that is approximately 1.1 mmol m-2 S-l photosynthetic photon flux density 

(PPFD). The light compensation point is relatively low for C3 

plants at approximately 0.05 mmol m-2 S-l PPFD. Western 

juniper appears to have a rather broad temperature optimum for assimilation; assimilation rates were within 80 

percent of maximum values over a leaf temperature range of 

15-35 C. Low temperature compensation point is near 0 C, 

and high temperature compensation point is near 45 C. 

Assimilation rates decline with increased plant water 

stress for both pinyon and juniper species (fig. 3). The 

declines for pinyon pine and singleleaf pinyon are very steep, 

with assimilation rates near zero at leaf water potentials 

between -1.5 and -2.5 MPa. Assimilation rates of Utah and 

one-seed juniper foliage do not reach zero until leaf water 

potentials ofapproximately-3.3 and-4.5 MPa, respectively. 

Assimilation and Leaf Nitrogen-Because nitrogen is 

essential for constructing enzymes, leaf nitrogen content is 

often related to assimilation rate. Leaf nitrogen content of 

both pinyon and juniper increase with nitrogen fertilization 

(Lajtha and Barnes 1991; Marshall and others 1994; Miller 

and others 1991). However, seasonal variations in leaf 

nitrogen content are small for both Utah and westernjunipers (fig. 1C). 

100 

80 

60 

E 

:J 

E 40 

.~ 

E 20 

-

0 

~ e..... 

0 

c:::: 

0 80 ~ 

'E 60 'w 

m « 40 

20 

A 

8 

one-seed juniper .,/" .,/" 

.,/" . .,/" . 

~ ~ 

/ 

/ ./ 

/ 

.,/" 

.,/" 

/ 

• •• •• Utah juniper 

0 

-5 -4 -3 -2 -1 

Predawn leaf \}' (MPa) 

Figure 3-Relationship between assimilation 

rate (expressed as a percentage of maximum) 

and predawn leaf water potential for: (A) singleleaf pinyon (closed circles, solid line) and pinyon pine (dashed line); and (B) Utah juniper 

(closed circles, solid line) and one seed juniper 

(dashed line). Data for singleleaf pinyon and 

Utah juniper are from Delucia and Schlesinger 

(1991: fig. 1), with solid lines as regressions of 

their data; dashed lines are second order and 

first order regression equations for pinyon pine 

and one-seed juniper, respectively, as reported 

by lajtha and Barnes (1991: table 1). 

38 

o 

As with many C3 plants (Field and Mooney 1986), assimilation rate of pinyon pine increases linearly with increased 

leaf nitrogen (fig. 4A). Thus, fertilization of pinyon plants 

leads to increased leaf nitrogen and consequently increased 

assimilation rates; in other words, increased availability of 

nitrogen in soil benefits pinyon pine through increased 

assimilation rates. The linear relationship between assimilation and leaf nitrogen content holds during both dry and 

wet portions of the year, although the slope of the relationship is much less during the dry portion of the year. Interestingly, results for fertilized and non-fertilized plants are 

along the same regression line for a particular part of the 

year (dry or wet). Thus, soil water availability, but not soil 

nitrogen availability, fundamentally changes the functional 

relationship between assimilation and leaf nitrogen. 

Evidence for a linear relationship between leaf nitrogen 

content and assimilation is mixed for juniper. Lajtha and 

Barnes (1991) did not find a significant linear relationship 

between assimilation rate and leaf nitrogen content for 

one-seeded juniper (fig. 4B). Although Marshall and others 

(1994) report a significant linear relationship for Utah 

juniper, the slope of the relationship for Utah juniper is 

120.------------------------------------. 

100 

80 

~60 

'm 

..... 40 '0) 

A 

~ 

rf 

~ o ~. ... 

pinyon pine 

" 

" 

(5 20 't:J 'V Dry season E Cb ~----; ..s 0 1--_-----'---C....--=--=-"-"-_WJ--"-w-=---_v-'---J~'__ __ \l__'__ __ _'__ _ ___1 

c:::: 

o 

~100 

:~ 80 m 

m 

« 60 

40 

8 

/ 

'<'I0~ .~~\'y 

. .\\.~~~ d' . 20 .I Sl ~~ n'1 _ one-see IUniper ~VVetseason 

o '--_-----' __ ~ __ ~~_~_=D~s~a~so~n~_'___~ 

o 5 10 15 20 25 

Leaf N (mg g-1) 

Figure 4-Relationship between assimilation and 

leaf nitrogen content for: (A) pinyon pine; and (B) 

Utah and one-seed junipers. For reference, the 

regression line for a number of other vascular 

plants from Field and Mooney (1986: fig. 1.2) 

(dot-dash line) is also shown in both panels. Data 

for pinyon pine and one-seed juniper are from 

Lajtha and Barnes (1991: fig. 3); closed symbols 

and solid line are data from the wetter portion of 

the year, open symbols and dashed lines are from 

the dryer portion, circles are from trees under 

natural soil nitrogen conditions, and triangles are 

from trees that were fertilized with nitrogen. Data 

for Utah juniper (open squares) are from Marshall 

and others (1994: fig. 2). All lines are first order 

regressions. 

30 35 

USDA Forest Service Proceedings RMRS-P-9. 1999 
much smaller than that reported by Field and Mooney 

(1986) for a number of plant species as well as for pinyon pine 

(fig. 4B). Thus, increased soil nitrogen availability, at best, 

only marginally increases the assimilation rate of junipers. 

Water Relations 

Plant Water Potential-Diurnal changes in leafwater 

potential (\}') occur for most plants, including pinyon and 

juniper. For Utah juniper in spring, \}' decreased from 

approximately -0.7 MPa to -1.7 MPa over the 4 hour time 

period from 6 AM to 10 AM, then remained near -1.7 MPa 

to about 1 PM (Ehleringer and others 1986). Between 1 and 

5 PM, leaf water status improved slightly to -1.5 MPa, but 

after 5 PM the rate of recovery increased greatly. By the end 

of summer, however, diurnal changes in \}' were very small 

for Utah juniper: \}' was between ~1.5 and -1.7 MPa for 

almost the entire time period from 8 AM to 6 PM. Diurnal 

measurements of \}' for singleleaf pinyon over 2 years at 

three different sites indicate a very rapid decrease in \}' from 

predawn measurements (Jaindl and others 1995). Typically, 

\}' of single leaf pinyon dropped to near its minimum value by 

7 or 8 AM, then was relatively constant until 3 PM. Unfortunately, measurements were not made after 3 PM, and thus 

we do not know how rapidly leaf water status recovered 

during late afternoon and evening. Malusa (1992) also observed a very rapid drop in \}' during early morning for 

pinyon pine and California pinyon (Pinus californiarum). 

Seasonal variation in \}' are relatively small for pinyon and 

juniper. Average values for predawn or midday measurements of \}' vary by approximately 1 MPa for Utah juniper 

over the summer (fig. 5A). For example, predawn \}' measurements averaged -1.8 MPa during midsummer in southern Utah, but averaged -0.6 MPa after a rainstorm at the 

end of summer. However, tree-to-tree variation under drought 

conditions was much larger than the seasonal variation: 

minimum and maximum predawn measurements in midsummer were -4.2 and -0.7 MPa, respectively, whereas 

those after the rainstorm wer.e -1.0 and -0.5 MPa, respectively (Marshall and Ehleringer 1990). Seasonal variation in 

\}' for westernjuniper is larger than that ofUtahjuniper: the 

difference between minimum and maximum predawn and 

midday \}' measurements during the year were approximately 2.0 MPa (Miller and other 1992). Seasonal variations 

in \}' for pinyon pine and California pinyon are generally less 

than 1.0 MPa for predawn measurements and quite small 

for midday measurements (figs. 5C, 5D). 

A key characteristics that is used to distinguish groups of 

pinyon pines is the number of needles per fascicle, and this 

feature has been hypothesized to have physiological, and 

hence evolutionary, significance. Neilson (1987) speculated 

that number of needles per fascicle in pinyons follows a 

gradient in summer precipitation, with four-needle Parry 

pine (Pinus quadrifolia) and five-needle Sierra Juarez pinyon (P. juarezensis) occurring at the conjunction of two 

summer moisture gradients whereas singleleaf pinyon is 

confined primarily to the Great Basin, which receives predominately winter precipitation. The rational for this speculation is that lack of summer precipitation induces greater 

water stress on plants with a greater number of needles per 

fascicle, and hence selects for plants with fewer needles. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

J F M A M J J A S 0 N 0 

0 

• -1 Predawn 

-2 ~ ~D __ .tJ 

-3 a --r - Midday 0 0 0 

-4 

A Utah juniper ~ ~~--~~--~--r--r--~~--~--r-~~ 

-1 

-2 

_-3 

<U 

~-4 a to. 

B western juniper ~ ~~~~~~~~~--~~--~~--~~~ ... . . ~ ~ 

-1 .------..------e ~ 0 

<L-2--(r-"t--..a.--~\J--O -2 0 (/ 

-3 

-4 

C pinyon pine ~ ~~--~~--._--r__.--~-.--_.--~-.~ 

-1 

-2 

-3 

-4 

o California pinyon 

~ ~----------------------------------~ 

Figure 5-Changes in predawn (closed symbols, 

solid lines) and midday (open symbols, dashed 

lines) plant water potential during the year for: (A) 

Utah juniper; (8) western juniper; (C) pinyon pine; 

and (D) California pinyon. Different symbol shapes 

indicate sources of data: for Utah juniper, circles are 

unpublished data of the authors and squares are 

from Ehleringer and others (1986: fig. 3) and Marshall 

and Ehleringer (1990: table 1); for western juniper, 

circles are unpublished data of the authors and 

triangles are from Miller and others (1992: fig. 6); for 

both pinyon species, data are from Malusa (1992: 

fig. 2). Error bars are standard errors. Although lines 

are from polynomial curve fitting, they are meant 

primarily as a guide to general trends of data. 

However, Malusa (1992) did not find any significant differences in midday \}' between the single-needle California 

pinyon and the double-needle pinyon pine over 2 years. 

Although significant differences in predawn \}' occurred, the 

trend was contrary to expectations: results from 

double-needle trees indicated less water stress than 

single-needle trees. 

Leaf Conductance and Transpiration-Water loss 

through transpiration ultimately is controlled by stomata, 

but few researchers have measured changes in stomatal 

conductance with changes in environmental factors for 

pinyon and juniper. Angell and Miller (1994) successfully 

simulated leaf conductance of western juniper by relaying 

39 
primarily on three environmental factors: soil temperature, 

soil water content, and vapor density deficit. In spring when 

soils are relatively moist, conductance increases as a hyperbolic function of soil temperature. Conductance is near its 

maximum value when soil temperature at 10 cm depth is 

above approximately 10 C, but conductance drops rapidly 

with decreased soil temperature to nearly complete stomatal closure when soil temperature is near 0 C. 

The relationship between conductance and soil water 

content is more complex: conductance is at its maximum 

value when soils are near field capacity, but conductance 

drops as a logistic function of soil water. Similarly, Miller 

and others (1995) found a curvilinear relationship between 

conductance and plant water potential for western juniper: 

conductance is near its maximum value when plant 'I' is 

above approximately -1 MPa, but drops to less than 20 

percent of its maximum value at plant '¥ less than -4 MPa. 

Finally, conductance linearly decreases with vapor density 

deficit: as relative humidity decreases and air becomes 

progressively dryer, stomata close. These patterns of stomatal response to environmental factors are not unlike 

400 

A - 350 en • 

"7 

0) 300 

0 

E 250 • 

.6 

Cl) 200 

0 

c: 

co 150 

-0 

:::J 

"'C 100 • c:: 

() 

0 50 Utah juniper H....I~~i 

0 

B 

1.4 

"7 (/) 1.2 

E 

E 

'-"' 1.0 

Cl) 

0 0.8 c: 

co 

-0 0.6 :::J 

"'C 

c:: 0.4 0 

() 

0.2 

0.0 

J F M A M J J A S 0 N D 

those noted in other Great Basin species (Smith and Nowak 

1990). 

As with assimilation, diurnal variation in conductance 

occurs for Utah juniper, western juniper, and singleleaf 

pinyon (Ehleringer and others 1986; Miller and others 1992; 

Jaindl and others 1995). Maximum conductance almost 

always occurs in morning, and often conductance peaks 

within 2-3 hours after sunrise. As soil water availability 

decreases during the year, the amplitude of the diurnal 

change in conductance decreases markedly .. In addition, 

singleleafpinyon has a general pattern of decreased diurnal 

amplitude of conductance with decreased soil water availability where variation in soil water availability occurred 

along an environmental gradient (Jaindl and others 1995). 

Variation in conductance over the year is somewhat larger 

than that of assimilation (figs. 6A, 6B). Conductance is 

highest in spring and early summer, then drops rapidly to a 

minimum value in late summer or early fall. Interestingly, 

both westernjuniper and singleleafpinyon exhibit increased 

conductance in late fall, with or without significant fall 

precipitation in the case of juniper (Angell and Miller 1994) 

- 200 ~ 

"7 175 

0) 

0 150 

E 

E 125 '-"' 

Cl) 100 en 

:::J 

~ 75 Cl) 

-

~ 50 

~ 25 'm 

0 0 

J F M A M J J A S 0 N D 

- 50 

0) 

~ 

'-"' 

(/) 

~ 40 :::J 

0 

...c 

ex) 30 ~ 

Cl) 

> 

0 20 Cl) 

(/) 

:::J 

'- 10 Cl) 

1ii 

~ 

20 40 60 80 100 

3 Canopy volume (m ) 

Figure 6-(A) Maximum conductance during the day for western (closed symbols, solid line) and Utah 

(open symbols, dashed line) junipers; (8) maximum conductance for singleleaf pinyon; (C) total daily 

water use for junipers; and (D) relationship between canopy volume of singleleaf pinyon and water use 

over the eight-hour period from 8 AM to 4 PM. Error bars are standard errors. Different symbol shapes 

in (A) and (C) indicate sources of data: circles are from Miller and others (1992: fig. 5); triangles are 

unpublished data of the authors. Data in (8) are from Jaindl and others (1995: figs. 4, 5). Regression 

line in (D) is from DeRocher and Tausch (1993: table 1). Except for (D), lines are meant primarily as 

a guide to general trends of data, even though they are from polynomial curve fitting. 

40 USDA Forest Service Proceedings RMRS-P-9. 1999 
or without significant fall precipitation in the case of pinyon 

(Jaindl and others 1995). 

The total amount of water transpired by a leaf over the 

entire day does not follow the same seasonal pattern as 

conductance. Leafwater use reaches a maximum in mid- or 

late summer for western and Utahjunipers (fig. 6C), whereas 

conductance tends to peak earlier (fig. 6A). This lag between 

conductance and transpiration occurs largely because vapor 

gradients have different effects on conductance and transpiration: everything else being constant, increased vapor gradients induce stomatal closure, but lead to increased transpiration rates. Although similar analyses have not been 

conducted for pinyons, whole tree water use over the day for 

singleleaf pinyon increased as amount of foliage increased 

(fig. 6D). As tree size increases, greater self-shading and 

stratification of the light environment within the canopy 

occur, and the exchange of water vapor from within the 

canopy to bulk air decreases, which in turn lead to the 

nonlinear relationship between tree size and water use 

(DeRocher and Tausch 1994). Thus, the amount of water 

used per unit of needle biomass was over six times greater for 

the smallest seedling than for the larger trees. In addition, 

number of resin canals greatly improved regressions between foliage biomass and whole tree water use' however 

the functional significance of the increased number ofresi~ canals to plant water use is not clear. 

Water Use Efficiency-The effects of drought conditions on water use efficiency are not consistent for either 

pinyon or for juniper. Daily water use efficiency, as calculated from daily carbon gain divided by daily water loss, is 

highest in spring and fall and lowest in midsummer and 

winter for junipers (fig. 7 A). During the year, lower water 

use efficiency tends to occur when plants experience greater 

water stress, unlike other Great Basin species that tend to 

increase water use efficiency with increased water stress 

(Toft and others 1989). However, results from sites across 

regional or elevational environmental gradients are not 

consistent with this inverse relationship between water use 

efficiency and drought stress. Daily water use efficiency was 

not significantly different among 6 mountain ranges that 

included either Utah or western juniper (fig. 2) nor was it 

significantly different between high and low elevations 

within each mountain range (unpublished results of authors). In further contrast, results from carbon isotope 

composition, which represents a long-term measure of water 

use efficiency, suggests the opposite trend for singleleaf 

pinyon, pinyon pine, and one-seed juniper: water use efficiency tends to be greater at low elevation sites (fig. 7B), 

which are assumed to represent sites with increased water 

stress. Jaindl and others (1993) corroborated this trend with 

irrigation treatments: more water decreased carbon isotope 

content, which indicates lower water use efficiency. Unfortunately, instantaneous measurements of water use efficiency do not help resolve the relationship between drought 

and water use efficiency. Instantaneous water use efficiency 

showed little variation as plant ~ decreased in pinyon pine, 

but for one-seed juniper, it increased gradually from -0.5 to 

-3.5 MPa, then declined rapidly as ~ decreased further 

(Lajtha and Barnes 1991). 

USDA Forest Service Proceedings RMRS-P-9. 1999 

-;_ 4 

'0 

E 3 

15 

E 

-S2 

w 

::> 

!:1 

~ 

'm A 

o O~~ __ ~~ __ ~ __ L-~ __ J-~ __ -L __ L-~~ 

J FM AM J J AS 0 N 0 

-22 r-----------------------------------~ 

singleleaf pinyon ---'-

o (irrigated) . - . - . - . ---. -23 

:) ~p~ f, ~nyon . ~ pine -24 

~ 

7.0 

-25 f one-seed juniper 

B 

-26 

1800 2000 2200 2400 2600 2800 

Elevation (m) 

Figure 7-(A) Daily water use efficiency for western 

(closed symbols, solid line) and Utah (open symbols, 

dashed line) junipers during the year. Different symbol shapes indicate sources of data: circles are data 

from Miller and others (1992: fig. 12) and triangles 

are unpublished data of the authors. (8) Carbon 

isotope composition of singleleaf pinyon (squares, 

dot-dash line), pinyon pine (circles, solid line), and 

one-seed juniper (diamonds, dashed line) for plants 

on study sites located at different elevations. For 

singleleaf pinyon, results are also shown for an 

irrigated plot at the lower elevation (open square). 

Data for singleleaf pinyon are from Jaindl and others 

(1993: table 2), and data for pinyon pine and one-seed 

juniper are from Lajtha and Getz (1993: table 2). For 

both panels: error bars are standard errors, and lines 

are meant primarily as a guide to general trends of 

data, even though they are from polynomial curve 

fitting. 

Comparative Ecophysiology 

Pinyon Versus Juniper 

Assimilation-Pinyon appears to have a greater potential for carbon gain than juniper. Maximum assimilation 

rates of pinyon pine are greater than those of one-seed 

juniper as measured under both controlled environment and 

natural, field-grown plants (Lajtha and Barnes 1991). Maximum rates for pinyon pine were 26-38 nmol g-1 S-1 in the 

controlled environment and slightly less under natural 

conditions. Maximum values for one-seed juniper were 

13-28 nmol g-1 S-1 in the controlled environment, but did not 

exceed 20 nmol g-1 S-1 in the field. As noted above (fig. 4), 

N fertilization greatly increases assimilation of pinyon pine, 

41 
but the response of assimilation to fertilization in one-seed 

juniper is very small. 

Although pinyon has a greater potential for carbon gain, 

the photosynthetic apparatus of juniper is more tolerant of 

water stress than that of pinyon. Assimilation for pinyon 

pine and singleleafpinyon drop much more rapidly with leaf 

\!' than for one-seed and Utah junipers (fig. 3). Whereas 

pines have essentially lost their ability for positive carbon 

assimilation at a leaf\!' of -2 MPa, assimilation is still at 35-

50 percent of capacity for junipers. 

Instantaneous water use efficiency of one-seed juniper 

were greater than those of pinyon pine under drought 

conditions, although they were similar under low water 

stress conditions (Lajtha and Barnes 1991). However, contrary to expectations, long-term water use efficiency as 

indicated by carbon isotope composition were slightly greater 

for pinyon pine than for one-seed juniper (fig. 7B) as well as 

greater for singleleafpinyon than for Utahjuniper (DeLucia 

and Schlesinger 1991); note that species comparisons of 

carbon isotope composition can be confounded by other 

factors, and direct interpolation to water use efficiency 

should be done cautiously. Interestingly, conflicting results 

have also been observed in studies of the effect of nitrogen on 

water use efficiency. Nitrogen fertilization increased instantaneous water use efficiency for pinyon pine whereas it did 

not affect that of one-seed juniper, but N fertilization did not 

affect long-term water use efficiency as indicated by carbon 

isotope composition in pinyon pine whereas it significantly 

increased that for one-seed juniper (Lajtha and Barnes 

1991). 

Water Relations-In addition to a greater tolerance of 

its photosynthetic apparatus to water stress, additional 

data also suggest that juniper has more favorable water 

relations than pinyon. In measurements of plant \!' over an 

elevational gradient, Barnes and Cunningham (1987) noted 

that \!' of one-seed juniper was less negative than that of 

pinyon pine when soils were wet, but more negative when 

soils were relatively dry. Hence, when water is plentiful, 

juniper has lower levels of water stress than pinyon; but as 

soils dry, juniper has a greater capability to tolerate water 

stress. Furthermore, this shift in relative ranking of \!' for 

these two species is due to the small seasonal variation in \!' 

for pinyon pine relative to that of one-seed juniper. Little 

variation in predawn \!' for pinyon pine also occurs across a 

seral gradient, whereas \!' of one-seed juniper becomes more 

negative as seral development nears climax (Schott and 

Piper 1987). Finally, water potential components such as \!' 

at the turgor loss point are good indicators of drought 

tolerance, and \!' at the turgor loss point was more negative 

for Utah juniper (mean over two sampling dates was -4.1 

MPa) than for pinyon pine (mean was -3.7 MPa) (Wilkins 

and Klopatek 1987). 

Recent evidence also suggests that one-seed juniper is 

better able to extract soil moisture from areas between 

canopies than pinyon pine (Breshears and others 1997). In 

a well-developed stand of pinyon-juniper woodland, 

Breshears and others (1997) documented a small, but significantly greater, difference in soil moisture in the area 

between tree canopies than that under tree canopies. By 

carefully measuring soil moisture content and both plant 

and soil 'f' under natural and irrigated conditions, they 

42 

determined that one-seedjuniper made better use of shallow 

soil moisture between canopies than pinyon pine. 

Responses of Juveniles Versus Adults-Both pinyon 

and juniper have dimorphic foliage that is associated with 

plant growth stage, but the physiological importance of 

juvenile versus adult foliage has only been investigated for 

western juniper. The physiological performance of juvenile 

foliage differs from adult foliage when soil moisture is 

relatively plentiful (Miller and others 1995). The maximum 

assimilation rate during the day of juvenile foliage is significantly greater than that of adult foliage from April to July 

(fig. 8A). This difference is maximum assimilation is partially due to increased stomatal conductance (fig. 8B). The 

greater assimilation rates of juvenile foliage results in a 28 

percent increase in carbon gain over the period from April to 

October, which likely aids in the rapid establishment of 

juvenile plants (Miller and others 1995). 

Unfortunately, the strategy of juvenile foliage to increase 

assimilation by increasing conductance has the cost of increased water use. The increased water use does decrease 

instantaneous water use efficiency of juvenile foliage with 

respect to adult foliage in late-summer (fig. 8C). However, 

water use efficiency ofthe two types offoliage does not differ 

during late spring and early summer, and water use efficiency of juvenile foliage is actually greater than that of 

adult foliage in early spring. None-the-Iess, increased water 

use does impact plant water status: midday \!' of juvenile 

foliage was lower than that of adult foliage over the entire 

measurement period of April through October, and predawn 

\!' of juvenile foliage was lower than that of adult foliage from 

July through October (fig. 8D). Thus, although increased 

water use of juvenile foliage only decreased water use 

efficiency in late summer, juvenile foliage experienced greater 

water stress over much of spring, summer, and fall. The 

more negative predawn \!' are especially intriguing: they 

suggest that juvenile western juniper depletes soil moisture 

faster than adults and/or have a smaller rooting volume. 

Juvenile and adult plants also differ in how they allocate 

their resources: juvenile plants allocate a larger proportion 

of their biomass to belowground tissues. Both the root:shoot 

ratio and the ratio of fine root:foliage are larger for juvenile 

westernjunipers than for sub-adults (fig. 8E). Although this 

greater allocation to roots likely helps juvenile junipers 

acquire soil moisture, greater allocation does not completely 

mitigate greater water use of juvenile foliage, as evidenced 

by more negative 'f' of juvenile foliage. The greater allocation 

to roots may also increase the ability of juvenile plants to 

compete with co-occurring species. 

Contrasts with Sagebrush 

Carbon Gain and Water Relations-The potential for 

carbon gain on a per gram of foliage basis are much lower for 

both juniper and pinyon than for co-occurring shrub-steppe 

species such as sagebrush. For example, maximum assimilation for sagebrush is approximately an order ofmagnitude 

greater than that for Utah juniper and about six times 

greater than that for singleleaf pinyon (fig. 9A). When 

expressed on a per unit nitrogen basis, differences between 

sagebrush and the conifers decrease, but sagebrush is still 

six and four times greater than Utah juniper and singleleaf 

USDA Forest Service Proceedings RMRS-P-9. 1999 
25~----------------------------------

20 

15 I.I..~ __ ""'I"" 

0.8 

"70) 

'0 0.6 

E 

.s 

0) 0.4 

~ ~ 0.2 

A 

B 

0.0 I------.J------'--------'------'--------'-------'-------j 

c 

A M J J A s o 

o~------------------------------~ 

m 

Q.. -1 

~ 

15 

~ -2 

i -3 Q) 

~ -4 

1: 

m 

a:: -5 

A 

o 

M J J A S o 

1.0 ~------------------rE 

0" '!::-o 

0.8 'f..'?3 ~oo 

o 0.6 

iii 

0::: 0.4 

0.2 

0.0 

Juvenile Small adult 

Figure 8-(A) Maximum assimilation rate during the day; (8) maximum stomatal conductance 

during the day; (C) instantaneous water use efficiency; (D) predawn (circles) and midday (inverted 

triangles) plant water potentials; and (E) root:shoot (solid bar~) and fine rootfoliage (o~en b~rs) 

ratios for juvenile and adult western juniper. Closed symbols In panels (A)-(D) are for Juveniles, 

and open are for adults. Error bars are standard errors. Data are from Miller and others (1995: 

tables 1, 3) except for data in (E), which is from Miller and others (1990: table 5). 

pinyon, respectively. In addition, stomatal conductance, leaf 

nitrogen content, and leaf phosphorous content of sagebrush 

are also significantly greater than those for the conifers 

(DeLucia and Schlesinger 1991). 

Assimilation of sagebrush is also more drought tolerant 

than that of the conifers. The drop in assimilation with 

increased drought stress is more gradual for sagebrush than 

for one-seed and Utah junipers, and much more gradual 

than for singleleaf pinyon and pinyon pine (fig. 9B). To 

extend comparisons made above: when predawn 'l' is near 

-2 MPa, assimilation rates of the 2 pinyon species are near 

zero, that of Utah juniper is approximately 1;3 of maximum, 

that of one-seed juniper is near Y2 of maximum, while that of 

sagebrush is near % of maximum. Interestingly, water use 

efficiency of sagebrush is less than that of the conifers. 

However, high water use efficiency under competitive, 

water-limited conditions may not confer a large ecological 

advantage (DeLucia and Schlesinger 1991): during the first 

USDA Forest Service Proceedings RMRS-P-9. 1999 

part of the growing season when water-limited condit~ons 

have yet to occur, water that is not used by the more efficIent 

conifers will likely be used by co-occurring species. 

Water and Nitrogen Sources-Pinyon pine and Utah 

juniper are more dependent on the episodic availability of 

water near the soil surface than sagebrush. Using the stable 

isotope deuterium in water, Flanagan and others (1992) 

demonstrated that pinyon pine and Utah juniper have a 

greater reliance on summer precipitation than sa~e~ru~h. 

They measured the deuterium content (3D) ofprecipitatlOn 

at their study site (closed diamonds and solid line in fig. IDA). 

If 3D of water in xylem of plants is near or above this 

precipitation line, then the plant is predominantly utilizing 

current precipitation as its water source. In April, all three 

species had similar 3D values, which means that all three 

species were utilizing similar sources of water (current 

precipitation as well as water stored in the soil profi.le). 

However, from late spring to midsummer, the two comfer 

43 
00r-----------------------------------' 

A 

Ramsey Mine Virginia Mountains 

_100r---------------------~~--.. --~--, 

~ 00 _: .; J" B 

- •• -;::ry / o .........- •. . 

~ 60 ,.....V) : f/ ~ ,..... /:/' .- •• ~ / I ]! e,..... /. 'E20 ,..... / A 

~ Jumo""" Juo.s./ / Pied /1 Pimo 

OL-----~------~----~~----~------~ 

-5 -4 -3 -2 -1 0 

Predawn leaf \}' (MPa) 

Figure 9-(A) Maximum assimilation (solid 

bars) and photosynthetic nitrogen use efficiency 

(shaded bars) for sagebrush and Utah juniper 

at two study sites and for singleleaf pinyon at 

the second study site. (8) Relationship between assimilation rate (expressed as a percentage of maximum) and predawn plant water 

potential for sagebrush (circles and solid line), 

contrasted with those for junipers (dashed lines; 

Jumo = one-seed juniper and Juos = Utah 

juniper) and pinyons (dot-dash lines; Pied = 

pinyon pine and Pimo = singleleaf pinyon). 

Lines are first order regressions, and lines for 

junipers and pinyons are the same as shown in 

figure 3. Data in (A) and for sagebrush in (8) are 

from Delucia and Schlesinger (1991: table 1, 

fig. 1). 

species had 8D values near or above the precipitation line 

whereas 8D of sagebrush was substantially below the line. 

Hence, the two conifers had greater reliance on current 

precipitation during late-spring to midsummer time period. 

Even by late summer, when 8D of sagebrush suggests use of 

current precipitation, the relative ranking of the three 

species suggest that a greater proportion of water for the 

conifers came from shallow soils. These results plus measurements of plant water potential suggest that the conifers 

have a greater proportion of their active roots in shallow 

soils than sagebrush (Flanagan and others 1992). This 

greater proportion of roots in shallow soils for the conifers 

does not necessarily imply that they are more able to exploit 

summer precipitation than sagebrush: in a year with a dry 

spring and early summer, roots of sagebrush were more 

responsive to small precipitation events during summer 

than Utah juniper (Flanagan and others 1992). 

Utah juniper appears to receive a large proportion of its 

nitrogen from shallow soils. Evans and Ehleringer (1994) 

44 

used measurements of the nitrogen stable isotope content 

(815N) of plant tissues to determine the source of nitrogen for 

Utah juniper, pinyon pine, and sagebrush. 815N of nitrogen 

fixed by ni trogen fixation, incl uding that fixed by cryptobiotic 

crust at their study site, is zero (fig. lOB). If 815N of plant 

tissues is near zero, than the plant acquires most of its 

nitrogen from nitrogen fixation; as 815N increases, the proportion of nitrogen from nitrogen fixation decreases. 815N of 

Utahj uni per was very close to zero, whereas those for pinyon 

pine and sagebrush were greater than zero, although similar 

to each other (fig. lOB). Thus, Utah juniper appears to 

acquire most of its nitrogen from nitrogen fixation by the 

cryptobiotic crust, and the portion of the root system that is 

most active in nitrogen uptake must be in close proximity to 

the cryptobiotic crust. 

Community-level Foliage Biomass-For sites with 

the same potential resources, foliage biomass of singleleaf 

pinyon communities greatly exceeds that of shrub communities. Total foliage biomass per unit ground area of both 

singleleaf pinyon and sagebrush dominated communities 

have significant positive relationships with site potential 

(Tausch and Tueller 1990). In addition, total foliage biomass 

-60 

• 

A 

-80 

_8 

<L0 

c.o -100 

J FM AM J J AS 0 NO 

2 .-----------------------.------------, 

N-fixation = 0 B 

Figure 10-(A) Deuterium stable isotope 

content (8D) of precipitation (solid diamonds, 

solid line) and of xylem water from pinyon 

pine (open circles), Utah juniper (opsn inverted triangles), and sagebrush (open 

squares) during the year. Line is a second 

order regression of the precipitation data, 

and error bars are standard errors. Data are 

from Flanagan and others (1992: fig. 1, 

table 1). (8) Nitrogen stable isotope content 

(815N) of foliage from Utah juniper, pinyon 

pine, and sagebrush. Data are from Evans 

and Ehleringer (1994: table 1). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
of shrub-dominated communities has a significant positive 

relationship with that of adjacent singleleaf pinyon-dominated communities with the same site potential (fig. 11A). 

However, this relationship is heavily weighted in favor ofthe 

trees. Furthermore, the relationship is not uniform over the 

range of site potential: foliage biomass of pinyon exceeds 

that of the sagebrush-dominated community by a factor of 

25 on low potential, drier sites but only by a factor of 12 on 

the sites with the highest potential (fig. lIB). Thus, given 

the same water and nutrient resources on a site, pinyon is 

able to sustain considerably more foliage biomass than 

sagebrush. The lower nutrient content of pinyon foliage 

likely contributes to the ability of pinyon to support much 

more foliage per unit ground area on any particular site. 

Although the physiological performance of sagebrush exceeds that of pinyon when measured on a per unit foliage 

basis, the greater foliage biomass per unit ground area for 

the conifers appears to compensate for their conservative 

ecophysiology. The average increase in foliage biomass over 

the range of sites in figure lIB was about 16. Thus, even 

though the assimilation rate per unit foliage of sagebrush 

is four to six times greater than that of pinyon, the 

'i'~ ~ 100 

0)..2 

- Q. 1/)'0 

I/) CD raE ~ 0'-

:c~ 

&"9 

ra..c 

:..::::J 

o ~ 

-~ - I/) J!!c 0'-

~ 

..c 

:::J 

80 

60 

40 

20 

600 

A 

• 

800 1000 1200 1400 

Total tree foliage biomass (g m-2

) 

in tree~ominated plots 

1600 

~ 30~--------------------------------~ I/) 

iU 

CD 

~ 25 o 

:p 

~ 

I/) 20 I/) 

ra 

E 

.Q 15 ..c 

CD 

0) 

8 

• 

.!!! 1 0 ~ ______ -J... _______ -'--______ --'-______ --' 

;f 6 789 

Site potential index 

Figure 11-(A) Relationship between total foliage 

biomass of singleleaf pinyon in plots dominated by 

pinyon and total foliage biomass of all species in 

plots dominated by shrubs for paired plots on sites 

with different site potential. (8) Relationship between site potential, as indicated by a site index 

based upon tree height at age 200 years, and the 

ratio of foliage biomass of pinyon in plots dominated by pinyon to foliage biomass of all species in 

plots dominated by shrubs. For both (A) and (8), 

lines are linear regressions. Redrawn from Tausch 

and Tueller (1990; figs 4 and 5). 

USDA Forest Service Proceedings RMRS-P-9. 1999 

10 

pinyon-dominated community has the potential to assimilate at least two to three times more carbon than 

sagebrush-dominated communities when measured on a 

ground area basis. The differences in foliage biomass in 

figure lIB were determined at peak biomass in early to mid 

summer. During late-fall, winter, and early-spring, sagebrush and associated perennial grasses lose a large proportion oftheir foliage, whereas pinyon loses almost none. Thus, 

during these time periods, and especially in early spring 

when growth starts, the potential for carbon gain by pinyon 

is even greater than the 2-3 times indicated above. Water 

use would follow an analogous pattern: greater foliage biomass per unit ground area of pinyon overcompensates for 

more conservative water use per unit foliage, with the 

difference between pinyon and the shrub-steppe community 

enhanced during earlier spring when water availability is 

near its peak. However, the extent that these differences in 

phenology and size confer a competitive advantage for pinyon needs a thorough investigation. N one-the-Iess, these 

opposite differences in ecophysiology and foliage biomass 

between sagebrush and pinyon appear to be important for 

community changes. Tausch and West (1995) found that the 

period of rapid increase in tree dominance and in understory 

suppression began when pinyon foliage biomass was over 

twice that ofthe sagebrush community on a unit ground area 

basis, which corresponds with the time that potential carbon 

gain as well as potential water use of pinyon on a per unit 

ground area is roughly equivalent to that ofthe shrub-steppe 

community. Interestingly, the shift in species dominance 

also occurs after the pinyons have largely lost their juvenile 

foliage. 

Discussion -------------------------------- The generally conservative ecophysiological traits of pinyon andjuniper appear to be at odds with its ability to alm~st 

triple its dominance of the landscape over the last 20 years. 

If sagebrush has superior ecophysiological traits, then why 

have the conifers been so successful at invading shrub-steppe? 

Clearly, ecophysiological traits do not provide, by themselves, the mechanism for success. However, these conservative traits may benefit the conifers in at least two major 

ways. First, accumulating evidence that nurse plants are 

important for establishment of juniper and almost essential 

for pinyon (Chambers and others, this volume) suggests one 

important role. Although nurse plants likely moderate microclimate for pinyon andjuniper seedlings, the conifers still 

must be able to tolerate reduced resource availability as well 

as compete effectively for resources. Interestingly, the ecophysiological performance of singleleaf pinyon seedlings is 

generally better when growing under sagebrush plants than 

when they grow in the open or in a location where sagebrush 

has been removed (Callaway and others 1996). A generally 

conservative ecophysiology as well as the attributes ofjuvenile foliage likely enhance the establishment and growth of 

pinyon and juniper under nurse plants. 

Second, their conservative ecophysiology, especially the 

low nutrient content per unit foliage, allow the conifers to 

produce much more foliage biomass per unit ground area 

than sagebrush. Thus, the conservative ecophysiological 

traits of these conifers coupled with their greater longevity 

45 
:." 

allow pinyons and junipers to establish, maintain growth 

under competitive conditions, and ultimately outsize and outlive their nurse plants and other shrub-steppe competitors. 

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transpiration in Juniperus occidentalis. For. Sci. 40:5-17. 

Barnes, F. J.; Cunningham, G. L. 1987. Water relations and productivi ty in pinyon -j uni per habi tat types. In: Everett, R L., compiler. 

Proceedings-pinyon -j uni per conference. 1986 Jan. 13-16, Reno, 

NV. Gen. Tech. Rep. INT-GTR-215. Ogden, UT: U.S. Department 

of Agriculture, Forest Service, Intermountain Research Station: 

406-411. 

Bazzaz, F. A. 1986. Life history of colonizing plants: Some demographic, genetic, and physiological features. In: Mooney, H. A; 

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Breshears, D. D.; Myers, O. B.; Johnson, S. R; Meyer, C. W.; 

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Juniperus"monosperma. J. Ecol. 85:289-299. 

Buckman, R E.; Wolters, G. L. 1987. Multi-resource management 

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Artemisia tridentata on desert vs. montane pines. Ecology 77: 

2130-2141. 

DeLucia, E. D.; Schlesinger, W. H. 1991. Resource-use efficiency 

and drought tolerance in adjacent great Basin and Sierran 

plants. Ecology 72:51-58. 

DeRocher, T. R; Tausch, R T. 1994. Predicting potential transpiration of single leaf pinyon: an adaptation of the potometer method. 

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Ehleringer,J. R; Cook, C. S.; TieszenL. L.1986. Comparative water 

use and nitrogen relationships in a mistletoe and its host. Oecologia 

68:279-284. 

Evans, RD.; Ehleringer, J. R 1994. Water and nitrogen dynamics 

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Flanagan, L. B.; Ehleringer, J. R; Marshall, J. D.1992. Differential 

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831-836. 

Jaindl, R G.; Doescher, P. S.; Eddleman, L. E. 1993. Influence of 

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Great Basin. For. Sci. 39:629-643. 

Jaindl, R G.; Eddleman, L. E.; Doescher, P. S. 1995. Influence of an 

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Range Manage. 48:224-231. 

Lajtha, K; Barnes, F. J. 1991. Carbon gain and water use in pinyon 

pine-juniper woodlands of northern New Mexico: field versus 

phytotron chamber measurements. Tree Physiol. 9:59-67. 

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northern New Mexico. Oecologia 94:95-101. 

46 

Malusa, J. 1992. Xylem pressure potentials of single- and 

double-needled pinyon pines. Southwestern Natur. 37:43-48. 

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Marshall, J. D.; Dawson, T. E.; Ehleringer, J. R 1994. Integrated 

nitrogen, carbon, and water relations ofaxylem-tapping mistletoe following nitrogen fertilization of the host. Oecologia 100: 

430-438. 

Miller, P. M.; Eddleman, L. E.; Kramer, S. 1990. Allocation patterns 

of carbon and minerals in juvenile and small-adult Juniperus 

occidentalis. For. Sci. 36:734-747. 

Miller, P. M.; Eddleman, L. E.; Miller, J. M. 1991. The response of 

juvenile and small adultwesternjuniper (Juniperus occidentalis) 

to nitrate and ammonium fertilization. Can. J. Bot. 69:2344-2352. 

Miller, P. M.; Eddleman, L. E.; Miller, J. M. 1992. The seasonal 

course of physiological processes in Juniperus occidentalis. For. 

Ecol. Manage. 48:185-215. 

Miller, P. M.; Eddleman, L. E.; Miller, J. M. 1995. Juniperus 

occidentalis juvenile foliage: advantages and disadvantages for a 

stress-tolerant, invasive conifer. Can. J. For. Res. 25:470-479. 

Neilson, R P. 1987. On the interface between current ecological 

studies and the paleobotany of pinyon-juniper woodlands. In: 

Everett, R L., compiler. Proceedings-pinyon-juniper conference. 1986 Jan. 13-16, Reno, NV. Gen. Tech. Rep. INT-GTR-215. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 93-98. 

Nowak, R S.; Caldwell, M. M. 1984. Photosynthetic activity and 

survival of foliage during winter for two bunchgrass species in a 

cold-winter steppe environment. Photosynthetica 18: 192-200. 

Schott, M. R; Pieper, R D. 1987. Water relationships of Quercus 

undulata, Pinus edulis, and Juniperus monosperma in seral 

pinyon-juniper communities of south-central New Mexico. In: 

Everett, R L., compiler. Proceedings-pinyon-juniper conference. 1986 Jan. 13-16, Reno, NV. Gen. Tech. Rep. INT-GTR-215. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 429-434. 

Smith, S. D.; Monson, R K; Anderson, J. A 1997. Physiological 

ecology of North American desert plants. Springer, New York. 

286 p. 

Smith, S.D.; Nowak, R S. 1990. Ecophysiology of plants in the 

Intermountain lowlands. In: Osmond, C. B.; Pitelka, L. F.; Hidy, 

G. M., eds. Ecological Studies, Vol. 80. Plant Biology of the Basin 

and Range. Springer-Verlag, Heidelberg: 179-241. 

Tausch, R J.; Tueller, P. T. 1990. Foliage biomass and cover 

relationships between tree- and shrub-dominated communities 

in pinyon-juniper woodlands. Great Basin Naturalist 50:121-134. 

Tausch, R J.; West, N. E. 1995. Plant species composition patterns 

with differences in tree dominance on a southwestern Utah 

pinon-juniper site. In: Shaw, D. W.; Aldon, E. F.; LoSapio, C., 

technical coordinators. Desired Future Conditions for 

Pinon-Juniper Ecosystems. 1994 August 8-12, Flagstaff Arizona. 

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Agriculture, Forest Service, Rocky Mountain Forest and Range 

Experiment Station: 16-23. 

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and carbon isotope composition of plants in a cold desert environment. Oecologia 80:11-18. 

Walter, H.; Harnickell, E.; Mueller-Dombois, D. 1975. 

Climate-diagram maps of the individual continents and ecological climatic regions of the earth. Springer-Verlag, Berlin. 

Wilkins, S. D.; Klopatek, J. M. 1987. Plant water relations in 

ecotonal areas of pinyon-juniper and semi-arid shrub ecosystems. 

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Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 412-417. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Harvesting Energy from 19th Century Great 

Basin Woodlands 

James A. Young 

T. J. Svejcar 

Abstract-The pinyon/juniper woodlands of the Great Basin were 

a vital source of structural wood and energy products for the mining 

industry from the 1860's to the 1930's. Pinyon and juniper were cut 

extensively for fuel wood and for the prod uction of charcoal, the only 

available fuel or energy source for the smelters of central Nevada. 

Firewood and fence post for ranches wexe also important uses of 

pinyon and juniper. Deforestation by cutting, promiscuous burning 

continued unabated until the 1920's and 1930's, when fossil fuels, 

substitute types of structural wood, and fire control combined to 

decrease disturbance in this vegetation type. 

This presentation is an updated adaptation of historical 

reviews first presented by Budy and Young (1979) and 

Young and Budy (1987). The vestiges of a once-flourishing 

wood products industry haunt the current managers of the 

pinyon-juniper woodlands. Land managers, users, and environmentalists alike suffer from a lack of historical perspective when they contend with management practices in 

pinyon-juniper woodlands. This is most apparent in the 

management of shrubs in pinyon-juniper woodlands as 

habitatformuledeer(Odocoileushemionussubsp.hemionus). 

The pinyon-juniper woodlands of the Great Basin are 

unique in how they relate to other types of vegetation. In 

the Rocky Mountains and the Southwest a forest of pine 

(often Pinus ponderosa) is usually located above the pinyonjuniper zone. In the central Great Basin, a mountain brush 

community occupies this site: The species composition of 

shrubs, forbs, and grasses in this community suggest a 

forest, but the trees are absent. In the Southwest, pinyonjuniper communities often merge with oak (Quercus) woodlands. Oaks are absent from central Nevada with the lower 

edge of the pinyon-juniper zone merging with Artemisia 

plant communities. Thus the central Great Basin was 

unique among nineteenth century mining areas where energy was a problem. Other portions of the west usually had 

some forest resources besides pinyon and juniper available 

for use. 

The mountain crest of the highest ranges of the Great 

Basin support five-needled pines, of which bristlecone (Pinus 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogd~n, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountam Research 

Station. 

James A. Young and T. J. Svejcar are Range Scientists, U.S. Department 

of Agriculture, Agriculture Research Service, Reno, NV and Burns, OR. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

longaeva) and limber pine (Pinus flexilis) are best known. 

Although the sparse forest were generally remote and 

limited in area, they were still heavily cut to supply mines 

with structural timbers and lumber. 

Mining in the West-Central Great 

Basin 

The mining era in Nevada was ushered in by discovery of 

the silver-rich Comstock Lode in 1859 and subsequent 

developments during the 1860's (Elliot 1973). As the mining 

districts on the Comstock grew in size, the supply of fire 

wood seldom met demand. The pinyon and juniper in the 

Virginia Range were removed in an ever expanding circle. 

In 1864, for example, several hundred American laborers 

were constantly cutting and hauling firewood from nearby 

woodlands. Chinese laborers followed the wood cutters, 

pulling up the brush, stumps, and roots from overcut hills. 

It was a common experience for boys growing up on the 

Comstock to spend their after-school hours searching mine 

dumps for discarded wooden candle boxes to feed the family 

heating stove (Galloway 1947). When 6 ft of snow covered 

the roads during the winter of 1866-1867, a cord of wood 

cost from $40 to $50. An estimated 120,000 cords offirewood 

were used in the district in 1866 (Lord 1883). The scant 

supply of pinyon and juniper on the neighboring hills was 

rapidly exhausted, and wood cutters moved to the eastern 

slopes of the Sierra Nevada, some 20 miles from the mines. 

Although the pine-fir forest ofthe eastside Sierra assured 

an abundant supply oftimber and fuel, transportation to the 

mines was expensive. The construction and maintenance of 

mountain roads became so costly that natural waterways 

were used whenever possible to move logs down to the mills 

in the valley below Virginia City. Because of the limited 

number and size of waterways, water transportation was 

not satisfactory until the 1870's when the V-flume was 

developed and proven practical. Then sawmills were erected 

in the mountains, and cordwood and timbers were transported down the flume from the Sierra. More than 700 cords 

of fuel wood and 500,000 board feet of mining timbers were 

transported down the Carson and Tahoe Lumber Company's 

flume daily (DeQuille 1889). Spring floods on the Carson 

River also were used for transporting wood. More than 

150,000 cords of wood were floated down the Carson in a 

typical season. 

Although the adjacent Sierra slope fulfilled much of the 

Comstock's demand for wood products, its use of pinyon and 

juniper was still extensive. The Comstock is located on the 

47 
edge of these woodlands in the Great Basin. Utah juniper 

extends north of the Comstock, but singleleafpinyon occurs 

south of a line running diagonally across Nevada, from 

Virginia City to the Idaho-Utah-Nevada corner (Beason 

1974). Mining operations along the Comstock Lode from the 

early 1860's until well into the present century drew upon 

this adjacent wood resource. As a result, more than 190,000 

acres of second-growth pinyon-juniper woodland now cover 

Douglas, Ormsby, and southernmost Washoe Counties 

(Wilson 1941). 

Use of wood in subsequent mining strikes and boomtowns 

in western Nevada and eastern California (for example, 

Aurora and Bodie) more or less followed the same pattern: 

transportation of fuel wood and timbers from the adjacent 

Sierra Nevada and secondary reliance on pinyon-juniper 

woodlands, especially for firewood. 

Mining in Central Nevada ___ _ 

In 1862 a former Pony Express rider who was cutting 

wood discovered silver ore in the Toiyabe Range, 175 miles 

east of Virginia City. This new find, around which grew the 

town of Austin and the Reese River Mining District, brought 

the wood energy crisis into sharp focus. Central Nevada was 

too far removed from the Sierra Nevada for the transportation of huge quantities of fuel. The pinyon-juniper woodlands alone had to sustain the mining industry. 

In contrast to the free-milling ores on the Comstock, the 

Reese River ores were called refractory or rebellious 

(Oberbillig 1967). The Reese River ores were dry crushed 

and roasted with salt to permit amalgamation with mercury. Although dry crushing was a terrible health hazard 

to the millworkers, it saved the cost of drying the crushed 

ore before roasting and prevented losses from oxidation of 

wet ores. The salt was harvested from playas in the desert 

valleys and often packed to the mines using camels (Young 

1982). 

During the 1860's, the Reese River mills used reverberatory furnaces in which the or~ was heated on hearths and 

roasted, with the flame passing across the top of the bed of 

ore. These furnaces took 7 hours to roast each charge of ore, 

consumed salt amounting to 8 or 10 percent of the ore 

volume, and burned a cord of wood per ton of capacity 

(Rossiter 1870). There was only one source of fuel for roasting the ore, and that was the pinyon-juniper woodlands. 

Roughly 60 percent of the expense of milling ore was for 

fuelwood. 

The efficiency of roasting was greatly improved by the 

development in 1869 of a new furnace by C. A. Stetefeldt. 

The principle of this furnace is that finely ground silver ore 

and salt are completely chloridized when they fall against a 

current of hot gas. The Stetefeldt furnace became the standard roasting mechanism for the central Great Basin until 

all amalgamation processes were replaced by the cyanide 

process early in the twentieth century (Oberbillig 1967). 

Only one-third as much wood was required with the 

Stetefeldt furnace as compared to earlier furnaces, and the 

labor requirement was greatly reduced. The technology 

developed on the Reese River Mining District provided the 

model for next three decades. 

48 

Charcoal Production -------------------- Despite savings in wood with the new technology, the 

energy source became very expensive once stands of pinyon and juniper adjacent to the mills were cut. There was no 

water transportation available in the arid mountains, so 

costs were reduced by carbonizing the raw wood to charcoal 

before transportation to the mills. 

The production of charcoal had a long history in Europe 

and was a part of all ancient civilizations. Industrial charcoal production, such as was practiced by the early iron 

smelting industry in Sweden, was a major cause of extensive 

deforestation. Spanish cultures had a long heritage of charcoal production from oak. Charcoal from oak was burned in 

California long before the gold rush. By carbonizing wood 

through controlled combustion, it was possible to obtain 

fairly high-energy-value fuel with a 60 percent savings in 

volume and about 80 percent savings in weight over raw 

cordwood. During the 1860's and 1870's, several million 

bushels of charcoal were produced in the northeastern United 

States for use in the manufacturing of iron (Hough 1878). 

The charcoal industry started in what became the United 

States with the construction of a kiln about 80 miles from 

Jamestown, Virginia in 1620 (Baker 1985). As the iron 

industry moved west to Pittsburgh, the demand for charcoal 

greatly increased. Charcoal iron production increased until 

1880, when about 800,000 tons were produced. 

Making charcoal from wood is essentially the process of 

partially burning the wood. The degree to which the wood is 

burned is controlled by regulating the amount of air admitted. Heat generated by burning the wood distills combustible vapors, which arise from wood surrounding the burning zone. The heat caused by the burning of these gases 

distills more gas from surrounding wood, and the zone of 

distillation moves progressively through the pile. Enough 

air is admitted to burn the gases, but not enough to burn the 

carbon residue, which is charcoal. If the burning process is 

correctly done, the result is good charcoal, relatively free 

from volatile and vaporous material (Anonymous 1943). 

A common industry in the eastern United States during 

the nineteenth century was the capture of and condensation 

of gases released by the charcoal burning process. Before 

petrochemical production, all industrial important organic 

chemicals were obtained from wood (Baker 1985). Most of 

these chemicals were obtained from hardwood-distillation. 

Longleaf pine (Pinus palustris) was important for the production of pine tars and oils from which turpentine was 

refined. Early miners in California and Nevada did distill 

pine oils from native trees. The sap of digger (Pinus sabiniana) 

and Jeffrey pine (Pinus jeffreyi) contain a volatile, explosive chemical which caused stills to explode (Mirov and 

Kraebel 1939). The precious metal milling and recovery 

industry in the Great Basin would have required large 

amounts of pine tar for waterproofing the largely hydraulic 

milling operations, but there is no record of singleleaf 

pinyon being distilled for pine tar production. 

Cutting singleleaf pinyon, Utah or western juniper for 

fuelwood is a miserable job. Mature pinyon and juniper 

trees seldom exceed 30 to 35 ft in height and 20 inches in 

diameter at the base. In addition to their small size, both 

species usually have poor growth form. Open grown trees 

USDA Forest Service Proceedings RMRS-P-9. 1999 
are often multi-stemmed and exceedingly bushy. Both species lack natural pruning, and thus retain branches right 

down to the ground. These characteristics make pinyon 

and juniper difficult to fell and buck into cordwood. We 

estimate that cutting a cord of pinyon wood required at least 

two or three times as much labor as cutting a cord of 

ponderosa pine. 

Pinyon logs were cut and allowed to dry before they were 

burned in earth-covered pits. The term charcoal pit is misleading. Although in the finished kiln the wood was completely covered with soil, the base was usually located at the 

soil surface. In construction of the pit, a center chimney was 

made, either by driving three poles into the ground and 

keeping them separate, or by building a triangular crib of 

wood in the center. The chimney was packed to part of its 

height with dry grass, twigs, or other loose combustible 

material. This material was used to start the fire. The 

chimney served as a support for the pile of wood and as a flue 

to aid the draft and carry off smoke. The charge of wood was 

piled around the central chimney, standing on end and 

leaning slightly toward the center. Top layers were put on 

flat, so the kiln was dome shaped. 

The entire mound, except for the central opening at the 

top, was covered with grass and pine needles to a depth of 

3 to 5 inches. This fine organic material was topped with 

2 to 5 inches of clay soil; sandy soil would not provide the 

correct seal. Care was taken to make the soil layer as air 

tight as possible. Small openings were left around the 

bottom for draft. The size of these holes was varied or 

controlled by putting in or taking out soil. 

Management of the burning process required considerable skill. The kiln was lit through the central chimney. 

Mter the fire was well started, the draft was reduced. 

Burning conditions were judged by the color of the smoke. 

The kiln had to be watched night and day, and wet clay was 

kept on hand to repair any cracks. A 100-cord pit kiln 

probably required from 3 weeks to a month to burn. 

When it was judged that all wood in the kiln had been 

completely burned, all openings were closed. The cooling 

process required a week to 10 days for large kilns. Opening 

the cooled kiln was a dangerous operation, best carried out 

when the wind was still. Unless it was completely cold, the 

kiln was always in danger of igniting the charcoal during 

the opening process. 

Utah juniper and curlleaf mountain mahogany (Cereocarpus ledifolius) were also converted to charcoal. These 

species required higher temperatures for conversion to 

charcoal than can be obtained with ground pits. To properly 

control overdrafts, beehive-shaped ovens were constructed 

from native stone (Grazeola 1969). Many perfectly symmetrical ovens remain today in isolated parts of Nevada 

as monuments to the back-breaking labor of a forgotten 

industry. 

The yield of cord wood from pinyon-juniper woodlands can 

vary from less than 1 cord to more than 12 cords per acre. 

A charcoal pit produced from 2,000 to 3,300 bushels of 

charcoal from a supply of 100 cords of wood. Therefore, 

roughly 10 to 100 acres of woodland had to be cut for each pit. 

Probably the lower yielding woodlands were too sparse for 

their use to be economical. A yield of 300 bushels of charcoal 

per acre may have been a reasonable average. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Eureka, about 60 miles east of Austin, Nevada, became 

important in the 1870's and 1880's. From 1869 to 1863 the 

Eureka District produced $60,000,000 of gold and silver 

and 225,000 tons of lead. Smoke from roasted ores was so 

severe, elongated stacks were run up the canyon walls and 

then vertically to vent the fumes from this Pittsburgh of 

the West. The major milling companies were processing 

750 tons of ore per day. The milling process required 25 to 

35 bushels of charcoal per ton of ore. An estimated 1.25 

million bushels of charcoal were consumed at Eureka in 

1875 (Anonymous 1875). 

The demand for charcoal was so great that deforestation 

became a severe problem. From our estimates of wood 

yield, 4,000 to 5,000 acres of woodland had to be cut annually 

to supply Eureka mills. By 1874 the mountain slopes around 

Eureka were denuded of pinyon and juniper for a radius of 

20 miles. The average hauling distance from pit to smelter 

was 35 miles (Anonymous 1875). 

Deforestation pushed shipping costs higher until the 

price of charcoal topped 30 cents per bushel. The standard 

transportation unit was 16- to 20-mule teams pulling four 

wagons, hitched in tandem, each loaded with 4 tons of sacked 

charcoal. 

Eureka is a well-documented, but not isolated, example of 

the use of pinyon-juniper woodlands. The spread of mining 

brought prospectors, with little and big boomtowns, to virtually every mountain range in Nevada (Paher 1970). 

In the far Northwestern Great Basin there is little evidence that western juniper (Juniperous oeeidentalis) was 

extensively cut during the settlement period (1870-1920) 

(Miller and Rose 1995). There was no large mining industry 

in eastern Oregon, and other wood resources were available 

through much of the region. It also appears the western 

juniper woodlands were limited in area compared to current 

conditions. Pre-settlement western juniper was often found 

on ridge-tops or on low sagebrush sites that were relatively 

safe from wildfires. In 1936 and 1937, during the establishment of the Squaw Butte Experimental Range near Burns, 

Oregon, crews traveled 40 miles to cut juniper posts to fence 

the range. Today, there are extensive western juniper woodlands on the experimental range. The pulse of western 

juniper establishment that has occurred in eastern Oregon 

is too recent to have provided wood resources during the 

early settlement period. 

Miners who operated north ofthe pinyon-juniper distribution in the Great Basin used drastic measures to obtain 

energy. The Dexter Mine at Tuscarora, Nevada, used sagebrush (Artemisia tridentata) to fire boilers. Sagebrush was 

cut and delivered to the mine for $2.50 per "cord." The 

hoisting woks smoked like a miniature Vesuvius and the 

entire area was covered with ashes (Paher 1970). 

In the early twentieth century, sagebrush was a major 

source offuel for settlers on the Minidoka irrigation project 

located in south-central Idaho. It was a mark of economic 

achievement when a family, trying to establish an irrigated 

farm in the desert reclamation project, could afford to switch 

from collecting sagebrush to purchased juniper or lodgepole 

pine (Pinus eontorta) as a source of fuelwood (Anonymous 

1924). 

49 
Other Uses of Pinyon-Juniper Wood 

Despite the huge demand for charcoal in mills, the use of 

pinyon and juniper wood in home heating and cooking may 

have had an even greater effect on the total woodland 

environment. The denuded area around Eureka, Nevada, 

accounted for a relatively small percentage of the pinyonjuniperwoodlands in the Great Basin. The 70-mile-diameter 

cutting circle contained roughly 2.5 million acres, of which 

0.6 million acres or 24 percent was pinyon-juniper woodlands; this equals 3.4 percent of the 17.6 million acres of 

this vegetation type in the Great Basin. Every isolated mine 

and ranch had to have wood as a source offuel and building 

material. The corrals, for example, at the Walti Hot Springs 

ranch in central Nevada are constructed of 3,000 juniper 

poles. Some 50 miles of barbed wire fence is supported by 

juniper posts, with 260 posts per mile. The woodlands above 

the ranch are laced with wagon roads among the stumps left 

from past use. One may multiply this example by the hundreds of ranches and thousands of mining prospects to estimate the true extent of use of the pinyon-juniper woodlands. 

When large ranches in the Humboldt Valley of Nevada 

were first fencing with barbed wire during the 1880's, they 

could buy redwood posts from California cheaper than 

juniper posts from the over-utilized woodlands of the Great 

Basin (Gordon 1880). Many ranchers employed Indian 

woodcutters to supply posts. Thirty Mile Charley was an 

enterprising Paiute resident of Montello, Nevada, who contracted with the giant ranches of the Utah Construction 

Company. His crews cut 3,000 to 4,000 posts per season 

(Bowman 1958). 

The accelerated use of pinyon-juniper woodlands also 

brought promiscuous burning. David Griffiths, a trained 

scientific observer, reported in 1902 that every mountain 

range in the northern Great Basin showed evidence of 

recent wildfires. He attributed most of the fires in areas 

remote from railroads to promiscuous burning. 

Sheep, cattle, and horses, Griffiths noted, heavily utilized 

the Great Basin ranges at the turn of the century. Domestic 

livestock did not eat the pinyon or juniper reproduction, but, 

by depleting the herbaceous understory vegetation, they 

favored the re-establishment of woody plants by reducing 

competition and changing the fuels available for wildfires. 

Depleted by promiscuous hunting to near extinction, mule 

deer herds grew at exponential rates during the first half 

of the twentieth century (Clements and Young 1997). This 

growth in mule deer populations paralleled the growth of 

shrub populations, especially in former pinyon-juniper woodlands. As trees re-established and eventually grew to dominance that depleted shrub populations, many mule deer 

populations have crashed. 

After World War I, the Great Basin gradually became 

dependent on fossil fuels for energy; first the cities and 

towns, and then, even more slowly, the rural areas. A 

declining rural population also helped to lessen use of 

pinyon-juniper woodlands. 

50 

References --------------------------------- Anonymous. 1875. Report of the state mineralogist. Carson City, 

NV; Appendix to the Journals of the Senate and Assembly, 

Seventh Session, Nevada State Legislature. 681. 

Anonymous. 1924. Federal reclamation by irrigation. A report 

submitted to the Secretary of the Interior by the Committee of 

Special Advisors on Reclamation. 68th Congress, 1st Session 

Document #92. GPO, Washington, DC. 104 p. 

Anonymous. 1943. How to make charcoal on the farm. Washington, 

DC; U.S. Department of Agriculture. 6 p. 

Baker, A. J. 1985. Charcoal industry in the U.S. A. In: Symposium 

on Forest Products Research International-Achievements and 

the Future: Vol. 5.1985 April 22-26: Pretoria, Republic of South 

Mrica. South African Council for Scientific and Industrial Research, National Timber Research Institute. 15 p. 

Beason, C. D. 1974. The distribution and synecology of Great Basin 

pinyon-juniper. M.S. Thesis, University of Nevada, Reno, NV. 95 p. 

Bowman, N. L. 1958. Only the mountains remain. Caxton Printers, 

Caldwell, ID. 93 p. 

Budy, J. D., and Young, J. A. Historical use of Nevada's pinyon! 

juniper woodlands. J. Forest History. 23: 112-121. 

Clements, C. D., and J. A. Young. A viewpoint: Rangeland health 

and mule deer habitat. J. Range Manage. 50:129-138. 

DeQuille, D. A 1889. History of the Comstock Silver Lode and Mines. 

F. BoogIe, Virginia City, NV. 127 p. 

Elliot, R. R. 1973. History of Nevada, University of Nebraska Press, 

Lincoln, NE: 62-65. 

Galloway, J. D. 1947. Early engineering works contributing to the 

Comstock. Geology and Mining Series No. 45. Nevada Bureau of 

Mines and Mackay School of Mines, University of Nevada, Reno, 

NV. 17 p. 

Gordon, C. Report on cattle, sheep, and swine: supplementary to 

enumeration of livestock on farms in 1880. Tenth Census ·of the 

United States, Vol. II, Washington, DC. 280 p. 

Grazeola, F. 1969. The charcoal burner's war of 1878: A study of 

Italian immigrants in Nevada. M.A. Thesis, University of 

Nevada, Reno, NV. 

Griffiths, D. 1902. Forage conditions on the northern borders of the 

Great Basin. Bulletin No. 15, Bureau of Plant Industry, U.S. 

Department of Agriculture. GPO, Washington, DC. 32 p. 

Hough, F. B. 1878. Report upon forestry, Vol. 1. GPO, Washington, 

DC: 127-128. 

Lord, E. 1883. Comstock mining and miners. U.S. Geological Survey; GPO, Washington, DC: 203-205. 

Miller, R. F. and J. A. Rose. 1995. Historic expansion of Juniperous 

occidentalis (western juniper) in southeastern Oregon. Great 

Basin Naturalist. 55: 37-45. 

Mirov, N. T. and Kraebel, C. J. 1939. Collecting and handling seeds 

of wildland plants. Civilian Conservation Corps, Berkeley, CA. 

Oberbillig, E. 1967. Development of Washoe and Reese River silver 

processes. Nevada Historical Society. 10: 30. 

Paher, S. 1970. Nevada ghost towns and mining camps. HowellNorth Books. Berkeley, CA. 492 p. 

Rossiter, R. 1870. Statistics of mines and mining in the states and 

territories west of the Rocky Mountains. GPO, Washington, DC: 

122-123. 

Wilson, R. C. 1941. Vegetation types and forest conditions of 

Douglas, Ormsby, and southwestern Washoe County, Nevada. 

California Forest and Range Experiment Station, Forest Service, 

U.S. Department of Agriculture, Forest Service Release No.2. 

Berkeley, CA. 1 p. 

Young, J. A. 1982. Camels on the western range. Rangelands. 4: 

248-251. 

Young, J. A. and Budy, J. D. 1987. Energy crisis in 19th century 

Great Basin woodlands. In: R. L. Everett. Proceedings-PinyonJuniper Conference. 1986 January 13-16 Reno, NV. Gen. Tech. 

Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Station: 23-29. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Biotic, Edaphic, and Other Factors 

Influencing Pinyon-Juniper Distribution 

in the Great Basin 

Kimball T. Harper 

James N. Davis 

Abstract-Drought and severe frost events during the growing 

season often limit the distribution of pinyon-juniper woodlands to 

relatively narrow altitudinal belts on mountain sides throughout 

the Great Basin and across the Colorado Plateau. Dramatic zone 

inversions may arise to confound more common patterns and place 

pinyon-juniper woodlands above the mountain brush zone. Such a 

zone inversion occurs on a grand scale in Spanish Fork Canyon, 

Utah County, Utah, where Utah juniper and Colorado pinyon have 

an ecological advantage over Gambel oak and associated mountain 

brush species. Utah juniper and associated pinyons are insensitive 

to differences in geologic parent materials and soils derived therefrom. Regional floristic patterns and climatic changes associated 

with differences in elevation exert a far stronger impact. Woodland 

successional processes proceed more quickly on deep deposits of 

volcanic ash and alluvium or lacustrine deposits than on soils 

derived in place from consolidated bedrock of volcanic or sedimentary origin. 

The pinyon-juniper forests of the Intermountain Region 

of western North America dominate literally millions of 

hectares of the landscapes of that area (West and others 

1975). In this paper, we evaluate the composition of pinyonjuniper forests growing on some of the most widespread 

and edaphically different geologic parent materials present 

in the Great Basin portions of Utah. 

Methods _________ _ 

Our sample has been gleaned from the files of the Utah 

Division of Wildlife Resources (DWR). For almost half a 

century, DWR personnel have monitored composition and 

health of big game winter ranges throughout the state. In 

our analysis of those records, we had three basic requirements for study site inclusion in this study: (1) geologic 

parent material at the site must be designated, (2) vegetational data must be quantified, and (3) soil physical and 

chemical characteristic must be reported. A total of29 sites 

were found in the DWR record file that satisfied all (or 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Kimball T. Harper is with the Department of Botany and Range Science, 

Brigham Young University, Provo, UT 84602. James N. Davis is with the 

Utah Division of Wildlife Resources Shrub Sciences Laboratory, 735N. 500 E., 

Provo, UT 84601. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

essentially all) of our requirements. In addition, we include 

some original data from our own work in Spanish Fork 

Canyon, Utah County, Utah. 

Vegetational data were taken along transects, each 270 m 

in length. Each transect line consisted offive transects 30 m 

in length. Transects alternated with 30 m segments that 

were not inventoried. Quadrats (1.0 m2) were placed at 3 m 

intervals along each transect beginning at the 0 point and 

alternating from the right to left sides of the survey tape. 

Cover was determined within each quadrat for each species 

using a slightly modified procedure from that described by 

Daubenmire (1959). Plant densities for grasses and forbs 

were determined by counting individuals rooted within the 

quadrats. Shrub densities were estimated along a 0.005 ha 

strip plot on each of the five transects centered over the 

survey tape. Frequencies for shrubs were based on occurrence within each of the 0.005-ha strips. Frequencies for 

forbs and grasses were based on species presence within any 

of the quadrats. Plant nomenclature follows Welsh and 

others (1993). Geologic stratigraphy in Spanish Fork Canyon has been taken from Hintze (1973, 1982). Climatic data 

were taken from National Oceanic and Atmospheric Administration (1992) summaries and from rain gauges maintained byus at Millforkduringthe frost-free seasons of1991-

1994. Soils were analyzed by the Soil and Plant Analysis 

Laboratory, Department of Agronomy and Horticulture, 

Brigham Young University using analytical methods recommended by Black and others (1965). Statistical analyses 

(analysis of variance, multiple range tests, and regression 

analyses) were made following procedures recommended 

by Sokal and Rohlf (1969). 

Results __________ _ 

Our sample represents pinyon-juniper woodlands growing on five major geologic parent materials in the Great 

Basin physiographic province of Western Utah (table 1). 

Each major parent material is represented by six or seven 

sites except for quartzite for which only three sites could be 

found and all of those lacked information on most chemical 

and physical characteristics of the soil. The study sites are 

similar with respect to elevation with sites on granite having 

the greatest average elevation (1,926 m) and those on sandstone the lowest elevations (1,341 m), but none of those 

differences are statistically significant at the p 0.05 level. 

Soil reaction averages were even more similar among sites 

(average values ranging from 7.5 to 7.7) (table 1). All soils 

were high in sand (41 to 57 percent). Soil skeletal (stone) 

content and available P were more variable. Sandstone 

51 
Table 1-Physical and chemical characteristics of pinyon-juniper sites and their soils on each of five different geologic parent materials in 

western Utah. Soil characteristics pertain to the surface 15 cm of the profile. Means followed by the same letter in superscript 

do not differ significantly. 

Parent material 

Characteristic Alluvium Granite Limestone Quartzite Sandstone 

No. of sites 7 6 7 3 6 

Average elevation (m) 1,709a 1,926a 1,824a 1,819a 1,341a 

Average soil pH 7.5a 7.5a 7.7a NA 7.5a 

Skeletal material (percent by vol.) 12a 24a 25a 43a 6a 

Sand (percent by wt.) 57b 46ab 41 a NA 43ab 

Available P (ppm) 73a 106a 31 a NA 71 a 

NA = not available 

sites had the least skeletal material (6 percent) in the upper 

soil profile, and quartzite sites had the most (43 percent). 

Available P was greatest (106 ppm) in soils derived from 

granite and least (31 ppm) in soils of limestone origin. 

However, since variances were great and sample sizes were 

small, none of the foregoing differences were statistically 

significant at the 0.05 probability level. 

Geologic substrate had ambiguous effects on vegetational 

characteristics of the pinyon-juniper woodlands examined 

(table 2). Because sample sizes are small and variances are 

large for all variables considered, almost none of the vegetational differences among parent material categories differed 

significantly (p < 0.05). Variables that did show some 

significant differences included proportions of species that 

were woody and proportions of species that were introduced. 

Woody species accounted for almost half of all species on 

sandstone parent materials and less than a quarter of 

the species on pinyon-juniper sites where soils were derived from limestone. Introduced species accounted for over 

20 percent of all species at pinyon-juniper sites on limestone, but both quartzite and sandstone soils had fewer than 

6 percent of their flora contributed by introduced species. 

Symphoricarpos oreophilus was a dominant understory species from sites above 1,800 m on quartzite parent material, 

but not on sites at similar elevations where parent materials 

were limestone or granite. 

The foregoing data show few indications that geologic 

parent materials alone have strong and predictable impacts 

on composition of vegetation in the pinyon-juniper zone in 

western Utah. In Spanish Fork Canyon, Utah County, Utah, 

however, strong differences in parent material do seem to 

interact with climatic differences to produce a major change 

Table 2-Characteristics of the vegetation of pinyon-juniper woodlands growing on various geological substrates in western Utah. Tree composition data were not tested for significance of differences because stands were at different successional stages. Other data were 

tested for Significance of differences among parent material groups. Means followed by the same letter do not differ significantly. 

Parent material 

Characteristic Alluvium Granite Limestone Quartzite Sandstone 

Percent sum-tree-density 

Juniperus osteosperma (percent) 90.5 67.1 84.9 100.0 60.2 

Pinus edulis (percent) 0.00 0.00 14.8 0.00 39.8 

P. monophylla (percent) 9.5 32.9 0.3 0.00 0.00 

Average No. species sampled per site 19.7a 29.6a 27.3a 23.0a 18.8a 

Proportion species that are woody (percent) 27.2ab 26.3ab 23.4a 32.1ab 45.4b 

Understory living cover (percent) 36.9a 29.2a 29.1a NA 23.3a 

Proportion of species that are: 

Annual (percent of all species) 18.3a 16.8a 14.6a 3.9a 14.5a 

Introduced (percent of all species) 15.0bc 18.3bc 21.5b 5.9ac 5.5ac 

Dominant species 1 

Shrub Artemisia A. tridentata Gutierrezia Artemisia nova, Ephedra viridis, 

tridentata sarothrae Symphoricarpos G. sarothrae, 

oreophilus Opuntia polyacantha 

Perennial grass Poa None Elymus Elymus spicatus, None 

secunda spicatus Sitanion hystrix, 

Stipa hymenoides 

Perennial forb None None None Cryptantha sp. Astragalus sp., 

Eriogonum sp., 

Penstemon sp. 

1Dominant species were here considered to be those that produce measurable cover in over half the stands considered in a geological subgroup. 

52 USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 3-Soil and site characteristics under pinyon-juniper woodlands in the Mill Fork area of Spanish Fork Canyon. For comparison, 

we also report soil and site characteristics reported for Gambel oak sites. Data are derived from literature references as noted. 

Data for pinyon-juniper woodlands near Mill Fork are taken from Farmer (1995). 

Dominant vegetation 

Characteristic Pinyon-Juniper Oak 

Elevation (m) 1,920 1,676-2,286 (Harper and others 1985) 

Soil pH 7.9 (Farmer 1995) 6.6 (Allman 1953) 

7.5 (Statewide ave., Bunderson 

and others 1985) 

7.4 (Yake and Brotherson 1979) 

circumneutral (Harper and others 1985) 

Clay (percent by wt. in mid-profile) 28 (Farmer 1995) 38 (Allman 1953) 

24 (Bunderson and others 1985) 25 (Yake and Brotherson 1979) 

Sand (percent by wt. in mid-profile) 44 (Farmer 1995) 39 (Allman 1953) 

46 (Statewide ave., Bunderson 

and others 1985 

24 (Yake and Brotherson 1979) 

in relative placement of the pinyon-juniper zone in the vegetational sequence along an altitudinal gradient. Normally 

pinyon-juniper woodlands occur between sagebrush-grass 

and mountain brush vegetation (Woodbury 1954), but at the 

mouth of Spanish Fork Canyon, the mountain brush zone 

borders sagebrush-grass vegetation along the Wasatch Front. 

Dominated by Gambel oak (Quercus gambelii), bigtooth 

maple (Acer grandidentatum), Vasey sagebrush (Artemisia 

tridentata var. vaseyana), and a large number of other 

montane shrubby species, the mountain brush zone prevails 

between the valley edge at about 1,585 m and roughly 1,750 

m elevation. At that general elevation, Green River Shale 

becomes the dominant parent material. Green River Shale 

supports pinyon-juniper woodlands of typical composition 

and structure over large areas at this location. Green River 

Shale gives way to the Colton Formation near Gilluly at 

roughly 2,000 m. The Colton material, however, is much like 

Green River Shale in terms of degree of consolidation, 

texture, and chemistry and vegetational response is similar 

on the two parent materials. Thus pinyon-juniper vegetation is apparent on steep, south-facing slopes almost to 

Soldier's Summit Pass at 2,275 m. In the middle of the 

elevational belt where Green River Shale occurs, pinyonjuniper woodlands are present on both south-facing and 

north-facing slopes. On north-facing slopes, Symphoricarpos 

oreophilus is the major understory shrub. That species is 

uncommon on south-facing slopes except above 1,900 m. 

Vasey sagebrush and Oregon grape (Mahonia repens) are 

other common understory shrubs on north-facing slopes. 

Characteristics of soils developed on Green River Shale in 

the Mill Fork area of Spanish Fork Canyon are presented 

in table 3. Results suggest that soils in that zone are more 

basic and coarser textured than soils that underlie Gambel 

oak communities at that elevation elsewhere in eastern 

Utah County. Bunderson and others (1985) statewide averages for pinyon-juniper woodland are close to those observed 

for Green River Shale at Mill Fork (table 3). Leonard and 

others (1987) summarized all published information concerning soil characteristics associated with Utah juniper, 

Colorado pinyon, and single-leaf pinyon in Utah. They report that all three species have broad tolerances, but are 

best represented on loamy to silt loam soils. Juniper and 

single-leaf pinyon are most often found on soils that contain 

15-35 percent skeletal material by volume. Colorado pinyon 

occurred most often on soils that had 35-60 percent skeletal 

material. Leonard and others (1987) concluded that Utah 

juniper and Colorado pinyon occurred "often" on strongly 

alkaline soils. 

The data show that a distinct rain shadow occurs in the 

Mill Fork area (table 4). The normal pattern is for precipitation to increase with elevation (Harper and others 1980), 

thus providing more precipitation at mid-elevations where 

Table 4-Precipitation and average annual temperature along an altitudinal gradient that parallels Spanish Fork Canyon. 

Data for Spanish Fork Power House, Birdseye, and Scofield Dam are from a 30 year summary published by 

National Oceanic and Atmospheric Administration (1992). Result for Mill Fork were either measured directly by 

Farmer (1995) or were estimated using a linear regression model based on elevation at the three sites reported 

by NOAA. 

Characteristic 

Elevation (m) 

May - Oct. precip. (cm) 

Nov. - Apr. precip. (cm) 

Mean annual precip. (cm) 

Mean annual temperature (C) 

Spanish Fork 

Power House 

1,439 

22.5 

30.0 

52.5 

10.9 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Birdseye 

1,750 

19.0 

25.5 

44.5 

6.1 

Location 

Mill Fork 

1,920 

21.8 (4 yr measured ave.) 

23.4 (estimated) 

45.2 

5.6 (estimated) 

Scofield Dam 

2,326 

17.9 

17.9 

35.8 

2.3 

53 
mountain brush vegetation normally occurs than at lower 

elevations where pinyon-juniper woodlands commonly occur. Near the mouth of Spanish Fork Canyon, however, high 

mountains (>3,000 m) form the western edge of the Wasatch 

Front immediately adjacent to the Utah Valley (elevation 

<1,525 m). Elevations to the east of that initial crest are 

almost everywhere lower all the way to Soldier's Summit 

(some 26 km to the east), the watershed divide between the 

Great Basin and the Colorado River drainage system. AB 

shown in table 4, precipitation steadily declines from Spanish Fork to Scofield Dam despite a consistent increase in 

elevation. The unexpectedly high precipitation at Spanish 

Fork apparently owes its existence to a phenomenon known 

as the approach effect. Daubenmire (1947) has described 

the approach effect as a situation in which approaching air 

masses driven before prevailing winds begin to ascend 

before they reach a mountain barrier more-or-Iess at right 

angles to the dominant winds. The ascending air cools to dew 

point and releases some of its vapor as liquid (or crystalline) 

precipitation. 

Discussion ---------------------------------

Our results support the assumption that regional dominants should be somewhat indifferent to geologic parent 

materials that may differ on a small scale within a common 

macroclimatic zone. Both pinyon and juniper occur on a 

variety of parent materials in the eastern Great Basin 

without conspicuous and predictable differences in vegetational structure or composition. 

Regional differences are apparent in the pinyon-juniper 

woodlands of Utah, but they are better correlated with 

macroclimatic and floristic province differences than with 

geologic parent materials. Among the tree species, P. edulis 

occurs primarily east of the Wasatch Front and the high 

plateau complex that forms a mountainous border between 

the Colorado Plateau and the Great Basin. In contrast, P. 

monophylla is largely confined to the Great Basin portions 

of western Utah. Cliffrose (Purshia mexicana) is a conspicuous component ofpinyon~juniper woodland in an area 

largely congruent with P. edulis, but it is replaced by bitterbrush (Purshia tridentata) in most of the Great Basin. 

Orthocarpus purpureo-albus is a common native annual in 

understories of woodlands of southeastern Utah, but it is 

absent in the Great Basin. Shepherdia rotundifolia, a striking shrub of the Colorado Plateau woodlands, is unknown 

in the Great Basin. 

The remarkable zone inversion in Spanish Fork Canyon 

apparently owes its existence to a chance occurrence of a 

strongly alkaline parent material (Green River Shale) in an 

area affected by a persistent rain shadow. Steep topography 

throughout the area dominated by pinyon-juniper woodlands ensures that erosional rates remain rapid enough to 

preclude or seriously interfere with soil development processes that would likely make the sites more favorable for 

mountain brush species. It is doubtful that the reversal of 

mountain brush and pinyon-juniper in the altitudinal sequence of vegetational types could occur without the cooccurrence of strongly alkaline parent material, reduced 

precipitation and rapid geologic erosion. The rarity of such 

a reversal in the landscapes of western United States would 

seem to indicate that the congruence of the causal agents 

noted above is uncommon. 

54 

Although our data show no consistent effects of geological 

parent materials on pinyon-juniper woodlands composition, 

cursory observations in southwestern Utah suggest that 

successional processes are faster on deep volcanic ash deposits. Such sites also support what appear to be the more dense 

pinyon-juniper woodlands in the region. Tree growth rates 

seem more rapid as well. Although we have inadequate data 

to evaluate these observations, we suggest that they may 

have management implications and deserve study. 

Acknowledgments 

Research was promoted through Federal Funds for Statewide Big Game Range Trend Studies, Pittman-Robertson 

Project W-135-R-18, and Wildlife Restoration, PittmanRobertson Project W-82-R Study, through the Rocky Mountain Research Station, Forest Service, U.S. Department of 

Agriculture. 

References _________ _ 

Allman, V. P. 1953. A preliminary study of the vegetation in an 

exclosure in the chaparral of the Wasatch Mountains, Utah. Utah 

Academy of Sciences, Arts and Letters Proceedings. 30: 63-73. 

Black, C. A.; Evans, D. D.; White, J. L.; Ensminger, L. E.; Clark, 

F. E. (eds.). 1965. Methods of soil analysis, part 1: Physical and 

mineralogical properties, including statistics of measurement 

and sampling. American Society of Agronomy, Inc. Madison, 

Wisconsin. 770 p. 

Bunderson, E. D.; Weber, D. J.; Davis, J. N. 1985. Soil mineral 

composition and nutrient uptake in Juniperus osteosperma in 17 

Utah sites. Soil Science. 139: 139-148. 

Daubenmire, R 1947. Plants and Environment. John Wiley and 

Sons, New York. 424 p. 

Daubenmire, R 1959. A canopy-coverage method of vegetational 

analysis. Northwest Science. 33: 43-66. 

Farmer, M. E. 1995. The effect of anchor chaining pinyon-juniper 

woodland on watershed values and big game animals in central 

Utah. Master's thesis, Brigham Young University, Provo, UT. 46 p. 

Harper, K. T. 1989. Soil pH beneath Gambel oak canopies in 

Spanish Fork Canyon, Utah County, Utah. Unpublished. 

Harper, K. T.; Wagstaff, F. J.; Kunzler, L. M. 1985. Biology and 

management of the Gambel Oak vegetative type: A literature 

review. U.S. Department of Agriculture, Forest Service, General 

Technical Report INT-179. 31 p. 

Harper, K. T.; Woodward, R A.; McKnight, K. 1980. Interrelationships among precipitation, vegetation, and streamflow in the 

Uinta Mountains, Utah. Encyclia. 57: 58-86. 

Hintze, L. F. 1973. Geologic history of Utah. The Department of 

Geology, Brigham Young University, Provo, UT. 181 p. 

Hintze, L. F. 1982. Geologic highway map of Utah, reprinted. 

Department of Geology, Brigham Young University, Provo, UT. 

National Oceanic and Atmospheric Administration, National Climatic Data Center. 1992. Monthly station normals of temperature, precipitation, and heating and cooling degree days: 1961-

1990, Utah. Climatography of the United States No. 81. 31 p. 

Sokal, R R; Rohlf, F. J. 1969. Biometry. W. H. Freeman and Co., 

San Francisco. 776 p. 

Welsh, S. L.; Atwood, N. D.; Goodrich, S.; Higgins, L. C. 1993. A 

Utah flora, 2nd ed., revised. Brigham Young University Print 

Services, Provo, UT. 986 p. 

West, N. E.; Rea, K. H.; Tausch, R J. 1975. Basic synecological 

relationships in juniper-pinyon woodlands. pp 41-53 In: Gifford, 

G. F. and Busby, F. E. (eds.). The pinyon-juniper ecosystem: A 

symposium. Utah State University, College of Natural Resources 

and Utah Agricultural Experiment Station, Logan. 

Woodbury, A. M. 1954. Principles of general ecology. McGraw-Hill 

Book Co., Inc., New York. 503 p. 

Yake, S.; Brotherson, J. D. 1979. Differentiation of serviceberry 

habitats in the Wasatch Mountains of Utah. Journal of Range 

Management. 32: 379-383. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Description of Pinyon-Juniper and Juniper 

Woodlands in Utah and Nevada From an 

Inventory Perspective 

Renee A. O'Brien 

Sharon W. Woudenberg 

Abstract-Forests composed mostly of pinyon and/or juniper species cover more than 45.3 million acres in the Intermountain West. 

About 40 percent (18.0 million acres) of that area is in Nevada and 

Utah, where roughly 71 percent of the total forest land is pinyonjuniper and juniper forest type. The net volume of pinyon and 

juniper species in the two States is estimated at over 10.3 billion 

cubic feet, or about 137.5 million cords. Juniper makes up 63 and 

47 percent of the pinyon-juniper volume in Utah and Nevada, 

respectively. Fifty-eight percent of the total number of pinyon and 

juniper trees in Nevada, and 49 percent in Utah are pinyon. About 

53 percent of pinyon-juniper and juniper stands in Utah and about 

67 percent in Nevada are estimated to be between 40 and 120 years 

old. Almost 20 percent of stands in Utah and 9 percent of stands in 

Nevada have an age over 200 years. Only about 6 percent of Utah 

stands and less than 1 percent of Nevada stands show evidence of 

chaining. 

The objective of this paper is to present an overview of 

composition, structure, and productivity of pinyon-juniper 

and juniper ecosystems, focusing on data from recent Utah 

and Nevada State inventories. This paper will also demonstrate the use oflarge-scale inventory data for planning and 

decision making. 

Forest types composed of pinyon and/or juniper species 

cover approximately 45.3 million acres in the western States 

of Montana, Idaho, Wyoming, Nevada, Utah, Colorado, 

Arizona, and New Mexico. The Interior West Resource 

Inventory, Monitoring, and Evaluation (IWRIME) Program 

of the U.s. Forest Service, Rocky Mountain Research Station, conducts forest land inventories in these eight States 

as part of its national Forest Inventory and Analysis (FIA) 

duties. About 40 percent of the pinyon-juniper and pure 

juniper ecosystems in the area inventoried by IWRIME 

occurs in Nevada and Utah, where roughly 71 percent of the 

total forest land is pinyon-juniper or pure juniper forest 

type. 

This paper will focus only on the pinyon-juniper and 

juniper forest types in Utah and Nevada, with special 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Renee A. O'Brien is Analysis Team Leader and Sharon W. Woudenberg is 

Supervisory Forester with the Interior West Resource Inventory, Monitoring, 

and Evaluation Program of the U.S. Forest Service, Rocky Mountain Research Station, Ogden, UT 84401. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

emphasis on Utah. Utah is the Interior West State with the 

most complete and current forest inventory data base. In 

the past, IWRIME did not usually inventory National Forest 

System (NFS) lands, obtaining the numbers instead from 

NFS inventories for State and regional reporting. However, 

a cooperative agreement and funding from the U.S. Forest 

Service Intermountain Region resulted in a comprehensive 

inventory of Utah's forests that included NFS lands and all 

reserved lands and was completed in 1995. A Utah State 

report is currently being prepared (O'Brien, in preparation). 

Nevada also has a fairly comprehensive State inventory, 

which was conducted between 1978 and 1982. An area 

update was done in 1989, and the results of the Nevada 

inventory were published in 1992 (Born and others). The 

number of field plots on pinyon-juniper and juniper forest 

types in Nevada was 1,104, and in Utah, 1,212 (fig. 1). 

Also shown in figure 1 are parts of six ecoregions that 

occur in Nevada and Utah, as described by Bailey (1995): 

(1) American Semi-Desert and Desert Province, (2) Colorado 

Plateau Semi-Desert Province, (3) Intermountain SemiDesert Province, (4) Intermountain Semi-Desert and Desert 

Province, (5) Nevada-Utah Mountains-Semi-DesertConiferous Forest-Alpine Meadow Province, and (6) Southern Rocky Mountain Steppe-Open Woodland-Coniferous 

Forest-Alpine Meadow Province. 

Figure 1-Utah and Nevada ecoregions and IWRIME 

pinyon-juniper or juniper field plots. 

55 
Table 1-Area and net volume with percent standard error for pinyon-juniper and juniper 

forest types in Utah 1993, and Nevada 1989. 

State Forest type Attribute 

Utah Pinyon-juniper Area 

Volume 

Juniper Area 

Volume 

Nevada Pinyon-juniper Area 

Volume 

Juniper Area 

Volume 

Sampling Procedures _____ _ 

IWRIME uses a two-phase sampling procedure for State 

inventories, described in detail by Chojnacky (1998). The 

first, or photo interpretive, phase is based on a grid of sample 

points systematically located every 1,000 m across all lands 

in a State. Forestry technicians use maps and aerial photos 

to obtain ownership and stratification information. Field 

crews conduct the second, or field, phase of the inventory on 

a subsample ofthe phase one points that occur on forest land. 

Field procedures for Utah are described in detail in USDA 

(1994), and in USDA (1982) for Nevada. 

For the most part, the IWRIME sampling intensity on 

lands outside NFS lands in the Interior West is one field plot 

every 5,000 m, or about every 3 miles. The sampling intensity on NFS lands in Utah was double that of outside lands. 

In Nevada, National Forest System lands were not field 

sampled. Most data summaries presented in this report for 

Nevada are based on the 6,526,784 acres that were actually 

sampled. Area estimates for the 2,312,752 acres of NFS 

lands were based on photo interpretation information, and 

volume estimates in tables 1 and 2 were developed using 

stratum means (field plots) fr9m other ownerships. 

The IWRIME sample was designed to meet national 

standards of precision for forest attributes at State and 

regional levels. Standard errors, which denote the precision 

of an estimate, were computed for State totals of area and 

volume of the pinyon-juniper and juniper types in Nevada 

and Utah, and are presented in table 1. Standard errors are 

usually higher for smaller subsets of the data. 

Forest Composition and 

Structure 

Area 

FIA differentiates pinyon-juniper forest type (stands that 

have juniper and any pinyon present) from juniper forest 

type (purely juniper). It is estimated that Nevada has 

7,155,970 acres of pinyon-juniper forest type, composed 

mostly of singleleaf pinyon (Pinus monophylla) in association with Utahjuniper (Juniperus osteosperma) or occasionally Rocky Mountain juniper (Juniperus scopulorum). Two 

needle pinyon (Pinus edulis) may also occasionally be found. 

Juniper occurs without pinyon on about 1,683,566 acres, 

56 

Area Volume Percent standard 

acres thousand error 

7,766,307 2.3 

5,365,955 3.2 

1,382,400 7.3 

660,683 8.9 

7,155,970 1.3 

3,498,881 2.9 

1,683,566 5.6 

560,305 7.7 

usually on drier and lower elevation sites. The total area 

of pinyon-juniper and juniper combined is 8,839,536. An 

additional 25,043 acres of pinyon-juniper is estimated to 

occur on reserved areas, for a total of 8,864,579, with about 

19 percent being pure juniper. Sixty-nine percent of the 

pinyon-juniper and juniper forests in Nevada are administered by the Bureau of Land Management (BLM), 26 percent 

by NFS, and 5 percent are privately owned. 

It is estimated that Utah has 7,766,307 acres of pinyonjuniper forest type composed mainly of two needle pinyon or 

occasionally singleleaf pinyon in association with Utah 

juniper or occasionally Rocky Mountain juniper. Approximately 1,382,400 acres are occupied by juniper species 

occurring without pinyon. The total area of pinyon-juniper 

and juniper combined is 9,148,707 acres, with 15 percent 

being pure juniper (fig. 2). Sixty-one percent of the pinyonjuniper and juniper forests in Utah are administered by 

the BLM, 15 percent by NFS, 10 percent by other public, and 

13 percent are privately owned. 

Number of Trees 

The composition of the forest by individual tree species is 

one measure of forest structure. In Utah, it is estimated 

that the number of pinyon and juniper trees is about equal 

10,000 

1'1 Utah 

(/) 8,000 [J Nevada Q) 

"-

C,) 

co 6,000 

"0 

C 

co 

(/) 4,000 ::J 

0 

..c 

I- 2,000 

° Pinyon-juniper Pure juniper Combined 

Forest type 

Figure 2-Area of pinyon-juniper and juniper foresttypes 

in Utah and Nevada. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
(49 and 51 percent). Utah juniper makes up 92 percent, and 

Rocky Mountain juniper makes up 8 percent of the juniper 

trees. Twoneedle pinyon makes up 78 percent, and singleleaf 

pinyon makes up 22 percent of the pinyon trees. Pinyon 

makes up more of the small trees, with juniper comprising 

more of the trees greater than 7 inches diameter at root 

collar (d.r.c.). Fifty-eight percent of the total number of 

pinyon and juniper trees in Nevada are pinyon, but more of 

the trees 11 inches d.r.c. or greater are juniper. 

Stand Density 

Stand density index (SDI), as developed by Reineke (1933) 

is a relative measure of stand density that quantifies the 

relationship between trees per acre, stand basal area, average stand diameter, and stocking of a forested stand. The 

concept was developed for even-aged stands, but can also be 

applied to uneven-aged stands (Long and Daniel 1990). SDI 

is usually presented as a percentage of the maximum SDI 

for the type. A maximum SDI value of 465 was used for 

pinyon-juniper, and 344 for purejuniper. SDI was computed 

for each plot using those maximums, and the results were 

grouped into three classes. Figure 3 shows the three classes 

of SDI for each State. A site was considered to be fully 

occupied at 35 percent of SDI maximum, which marks the 

onset of competition related stresses and slowed growth 

rates. IWRIME estimates that 53 percent of pinyon-juniper 

stands in Utah and 49 percent in Nevada are at or above 35 

percent of SDI maximum. 

Stand Age 

Age information is relatively difficult to obtain for pinyonjuniper stands because of tree form and the difficulty of 

counting growth rings. In Nevada, 3 trees reflecting the 

average or above average size in the stand were bored to get 

stand age. Junipers were not included because of perceived 

60 

Utah 

50 

ro 

(l) 40 ~ 

ro 

+-' 

c 30 (l) 

() 

~ 

(l) 20 a.. 

10 

0 

Understocked Fully-stocked Overstocked 

(0-34.9%) (35-59.9%) (60%+) 

Stand Density Index (SOl) class 

Figure 3-Percent area of combined pinyon-juniper 

and juniper forest types by SDI class, Nevada 1989 and 

Utah 1993. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

40 

III Utah 

ro 30 Q) 

~ 

ro 

...... 

c 

Q) 20 

() 

~ 

Q) 

a.. 

10 

o 

1-4041- 81- 121- 161- 201- 251- 300+ 

80 120 160 200 250 300 

Stand age class 

Figure 4-Percent area of combined pinyon-juniper and 

juniper forest types where ages were collected by stand 

age class, Nevada 1989 and Utah 1993. 

difficulty in boring, so ages on pinyon-juniper forest land in 

Nevada only came from pinyons. This represents a bias, 

because pure juniper stands were not aged. Age data were 

obtained for about 62 percent of stands sampled in Nevada. 

In Utah, only one woodland tree of any species reflecting the 

average of the stand (based on cruiser judgement) was aged, 

but cores were collected at all locations. Cores for all woodland trees sampled in Utah were sent into the office for aging 

and storage. 

Even though the two States had different protocols for tree 

selection, the pattern of age distribution was similar for both 

States. Based on this admittedly scanty age data, it is 

estimated that about 53 percent of the stands in Utah, and 

about 67 percent of the stands where age was sampled in 

Nevada were between 40 and 120 years old (fig. 4). Only 

about 20 percent of the stands in Utah and 9 percent in 

Nevada were over 200 years. A report on old growth, "Characteristics of Old-growth Forests in the Intermountain Region" (USDA 1993), defines old-growth criteria for pinyonjuniper forest types using trees per acre, tree diameters, 

and tree ages. Screening with a combination of just two of 

the criteria, stand age and stand-size class, showed that 

14 percent of all Utah stands had an age of 200 years or 

greater and a stand size of 9 inches (d.r.c.) or greater. 

Figure 5 presents the percent area ofpinyon-juniper and 

juniper forest types (combined) by stand age class and 

ecoregion, and gives a rough indication of the differences 

among ecoregions. For example, more of the pinyon-juniper 

and juniper forest types in the Colorado Plateau SemiDesert Province have a stand age between 161 to 300 years 

than in the other ecoregions. The American Semi-Desert 

and Desert Province has the most extreme differences by 

age class, due probably to the small number of plots in that 

ecoregion. 

Because 120 years is roughly the amount of time since 

significant impacts from mining and settlement would have 

first been felt in these areas, the data for stands 120 years old 

or less was separated from stands greater than 120 years for 

57 
B Colo Plat 

·9 Semi 

50% . Desert 

co 

40% -fr Nv-Ut Mtns. 

Q) 

S.Rockies 10-

co 30% +-' 

B- American c 

Q) 

20% () 

10-

Q) 

0... 

10% 

0% 

1-40 41- 81- 121- 161- 201- 251- 301 

80 120 160 200 250 300 + 

Stand age class 

Figure 5-Percent area of combined pinyon-juniper and 

juniper forest types by stand age class and ecoregion, 

Nevada 1989 and Utah 1993. 

additional analysis. About 71 percent of the pinyon-juniper 

stands sampled for age in Nevada, and about 57 percent in 

Utah are estimated to be less than 120 years old. Crews 

make a subjective field assessment of the predominant 

human or natural disturbance on each plot that impacts the 

entire condition. The percent of area with stand age 120 

years or less is compared to the percent of area with stand 

age greater than 120 years in terms of evidence of disturbance in figure 6. The overwhelming majority of pinyonjuniper or juniper stands have no visible evidence of disturbance in either State. One of the categories of disturbance 

was chaining, which was evident on about only 6 percent of 

Utah plots 120 years old or less, and about 1 percent of 

Nevada plots 120 years old or less. 

Volume ___________ _ 

The total volume of wood in live pinyon and juniper trees 

on all forest types in both States is estimated to be in excess 

of 10.3 billion cubic feet. This number divided by a standard 

FIA conversion factor of75 gives an estimate of the number 

of cords-137.5 million. Table 2 displays cubic foot volume 

by species, owner, and State. 

90 

80 • 1-120 years (UT) 

70 121+ years (UT) 

co 

Q) 60 III 1-120 years (NV) 10-

co 50 tEl 121+ years (NV) C 

Q) 40 () 

10-

Q) 30 0... 

20 

10 

0 

None Cutting Other Fire Chaining 

Type of disturbance 

Figure 6-Percent area of combined pinyon-juniper 

and juniper forest types in each age category by type 

of visible disturbance, Nevada 1989 and Utah 1993. 

Volume of all species on pinyon-juniper andjuniper forest 

types averages about 459 cubic feet (6.1 cords) per acre in 

Nevada, and 659 cubic feet (8.8 cords) per acre in Utah. 

Figure 7 shows the difference in cubic foot volume per acre 

between ecoregions. The range is from less than 200 cubic 

feet per acre in the American Semi-Desert and Desert 

Province to over 800 cubic feet per acre in the Southern 

Rocky Mountain Steppe-Open Woodland-Coniferous Forest-Alpine Meadow Province. These differences in average 

volume per acre may reflect the climatic and geographic 

differences among the ecoregions. These estimates include 

other species that might occur on pinyon-juniper andjuniper 

forest types. 

Growth and Mortality ____ _ 

Growth for pinyon and juniper species is characteristically low, and is difficult to measure. However, it is estimated that the gross growth rate for Nevada and Utah is 1 

percent or less per year. The total mortality observed was 

only about 5 percent of growth in Nevada, and 15 percent of 

growth in Utah. 

Table 2-Net volume of pinyon and juniper species by state and owner group, (thousand cubic feet). 

Owner 

State Species National forest Other public Private Total 

Utah Pinyon 501,116 1,536,240 258,148 2,295,504 

Juniper 694,610 2,800,847 491,095 3,986,552 

Nevada Pinyon 548,906 1,437,842 153,811 2,140,559 

Juniper 361,110 1,407,143 120,898 1,889,151 

Total 2,105,742 7,182,072 1,023,952 10,311,766 

58 USDA Forest Service Proceedings RMRS-P-9. 1999 
900 

CD 800 t5 

(lj 

Q; 

700 

Q. 600 

1i5 

2 500 

() 

:0 400 ::J 

.s. 300 CD 

E 200 ::J 

(5 100 > 

0 

Amer. Colo. Semi- Desert NV-UT S.Roe. 

Plat. des. Mtns. Mtns. 

Ecoregion 

Figure 7-Cubic foot volume per acre on combined 

pinyon-juniper and juniper forest types, by ecoregion in 

Nevada 1989 and Utah 1993. 

References ---------------------------------- Bailey, Robert G., compiler. 1995. Descriptions of the ecoregions of 

the United States. 2nd ed. Misc. Pub. No. 1391. Washington DC: 

U.S. Department of Agriculture, Forest Service, Washington, 

DC. 108 p. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Born, J. David; Tymcio, Ronald P.; Casey, Osborne E. 1992. Nevada 

Forest Resources. Resour. Bull. INT-76. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research 

Station. 64 p. 

Chojnacky, David C. 1998. Double sampling for stratification: a 

forest inventory application in the Interior West. Res. Pap. 

RMRS-RP-7. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 15 p. 

Long, James N.: Daniel, Theodore W.1990. Assessment of growingstock in uneven-aged stands. Western Journal of Applied Forestry 5(3):93-96 . 

O'Brien, Renee A. [In preparation]. Utah forest resources. Resour. 

Bull. Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Research Station. 

Reineke, L. H. 1933. Perfecting a stand-density index for even-aged 

forests. J. Agric. Res. 46:627-638. 

U.S. Department of Agriculture, Forest Service. 1982. Nevada 

forest survey field procedures. Unpublished field guide on file at: 

U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Research Station, Forestry Sciences Laboratory, Interior West 

Resource Inventory, Monitoring, and Evaluation Program, Ogden, 

UT. 

U.S. Department of Agriculture, Forest Service. 1993. Characteristics of old-growth forests in the Intermountain Region. Hamilton, 

Ronald C., compiler. Unpublished report on file at Ogden, UT: 

U.S. Department of Agriculture, Forest Service, Intermountain 

Region. 

U.S. Department of Agriculture, Forest Service. 1994. Utah forest 

survey field procedures, 1994-1995. Unpublished field guide on 

file at: U.S. Department of Agriculture, Forest Service, Rocky 

Mountain Research Station, Forestry Sciences Laboratory, Interior West Resource Inventory, Monitoring, and Evaluation Program, Ogden, UT. 232 p. 

59 
An Example of Pinyon-Juniper Woodland 

Classification in Southeastern Utah 

Robert M. Thompson 

Abstract-In a study on the Monticello Ranger District, MantiLaSal National Forest, a continuous process was used in vegetation 

cover type classification, plant community classification, and mapping. Included are guidelines for dividing and classifying, as well as 

mapping instructions. 

The pinyon-juniper woodland vegetative type occurs on 

about 21 percent of Manti-La Sal National Forest lands. This 

woodland type forms dense, closed stands on mesa tops, in 

canyon bottoms, on alluvial outslopes, and as scattered open 

stands on steeper side slopes and canyon walls. 

The pinyon-juniper woodland vegetative type occurs in 

the 8 to 18 inch precipitation zone and at elevations between 

5,000 and 8,500 ft. Soils within this type have a wide variety 

of textures and depths. Some of the soil groups are U stochrept, 

Ustorthents, and Molliceutroboralfs. Parent materials range 

from sedimentary, limestone, sandstone, and shales to igneous formations. 

Vegetative cover type classification, plant community 

classification, and mapping is a continuous process. This 

paper describes a method for mapping and classification of 

some pinyon-j uni per woodlands and plant communities found 

on the Monticello Ranger District, Manti-LaSal National 

Forest, UT. 

Study Area ________ _ 

The study area (fig. 1) sele<;ted for site-specific pinyonjuniper woodland classification and plant community type 

mapping is located on the western half of the Monticello 

Ranger District, Manti-LaSal National Forest (South Cottonwood assessment area), UT. Generally, it includes all of 

the South Cottonwood drainage, the Dark Canyon Wilderness area, and the North and South Elk Ridges. There are 

176,548 acres in this study area. Pinyon-juniper woodland 

covers 68,782 acres or 39 percent of the study area. 

Classification of the Pinyon-Juniper 

Woodlands _________ _ 

The pinyon-juniper woodlands within the study area 

were classified and mapped at three different levels: 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.s. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Robert M. Thompson is Range Conservationist, Manti-LaSal National 

Forest, Intermountain Region, U.S. Department of Agriculture, Price, UT 

84501. 

60 

Level 1-Pinyon-juniper (woodlands); Levei 2-Pinyonjuniper (associations); and LeveI3-Pinyon-juniper (plant 

communities). 

Level 1-Pinyon-Juniper Woodlands 

Pinyon-juniper woodlands can be divided into four broad 

types: (1) Pinyon-juniper mixed woodlands; (2) Utahjuniper 

woodlands; (3) Pinyon woodlands; and (4) Rocky Mountain 

juniper woodlands. 

Guidelines were developed to divide and classify the 

various woodland types. 

Data obtained from study plots and site ocular observations are used to determine the composition of the overstory 

trees. 

Woodland Classification 

Dominant tree species make up 90 to 100 percent of 

the overstory composition. 

Utah juniper trees dominate 

-Utah j uni per woodlands 

Pinyon pine trees dominate 

-Pinyon woodlands 

Rocky Mountain juniper trees dominate 

-Rocky Mountain juniper woodlands 

Dominant tree species make up 20 to 70 percent of 

the overstory composition. 

Mixed stands of pinyon and Utah juniper 

-Pinyon-juniper mixed woodlands 

Mixed stands with Rocky Mountain juniper 

Rocky Mountain juniper make up 50 to 70 

percent of the tree composition 

-Rocky Mountain juniper woodlands 

Rocky Mountain juniper make up 10 to 30 

percent of the tree composition 

-Pinyon-juniper mixed woodlands 

Level 2-Pinyon-Juniper Plant 

Association 

A plant association is a combination of the dominant 

overstory tree species with a dominant understory plant 

species. When combined, they form a characteristic ecologic 

association. 

Some plant species tend to give a dominant visual character to a site even though they are not the most abundant 

plant on the area. These plants may also be used to classify 

or determine a plant association. Introduced species should 

not be used. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Select those dominant plant species that are common to 

the site, soils, aspects, geologic formations, and elevations. 

Association Classification 

Existing dominant shrub species make up 70 to 100 

percent of the understory composition. 

Associated Dominant Understory Shrub Species 

Black sagebrush Artemisia nova (ARNO) 

Basin big Artemisia Tr. tridentata (ARTRT) 

sagebrush 

Mountain big 

sagebrush 

True mountainmahogany 

Littleleaf mahogany 

Bitterbrush 

Serviceberry 

Snowberry 

Roundleaf 

buffaloberry 

Artemisia Tr. vaseyana (ARTRV) 

Cercocarpus montanus (CEMO) 

Cercocarpus intricatus (CEIN) 

Purshia tridentata (PUTR) 

Amelanchier alnifolia (AMAL) 

Symphoricarpos oreophilus (SYOR) 

Sheperdia rountifolia (SHRO) 

Oakbrush Quereus gambelii (QUGA) 

Green ephedra Ephedra viridis (EPVI) 

Greenleaf manzantia Arctostaphylos patula (ARPA) 

Shrub species make up only 10 to 40 percent of the 

understory species composition. Several species may 

be present, none dominate. 

Mixed mountainbrush 

No understory shrub species present 

Use dominant understory ground 

cover plant species present. 

Level 3-Pinyon Juniper Plant 

Communities and Habitats 

A plant community is a combination of the overstory 

dominant tree species, shrub ·or dominant understory species, and dominant ground cover species three-layered. 

Study plot data and some visual observation can be used 

to determine the dominant ground cover species. Plant 

species that are common to the existing soils, geologic 

formations, aspects, and elevations should be the prime 

candidate for selection for community classification. 

Dominant species make up 40 to 100 percent of the 

ground cover species composition. 

Select most dominant plant 

species for community. 

Dominant species make up only 20 to 30 percent of the 

species composition. (Some once-dominant species that 

have been reduced to less than 5 to 20 percent of the 

composition, but are characteristic of a site, may be 

used to classify a type.) 

Select most representative plant 

species. 

No ground cover species present. 

Lichens present 

Annuals present 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Dominant Ground Cover Plant Species 

Rosses sedge Carex rossii (CARO) 

Dwarf lousewort Pedicularis centranthera (PECEN) 

Desert goldenrod Petradora pumila (PEPU) 

Western wheatgrass Agropyron smithii (AGSM) 

Salina wild ryegrass Elymus salinus (ELSA) 

Indian ricegrass Oryzopsis hymenoides (ORRY) 

Needlegrass Stipa comata (STCO) 

Galleta grass Hilaria jamesii (HIJA) 

Mutton grass Poa fondleriana (POFE) 

Sandberg bluegrass Poa secunda (POSE) 

Pinyon-Juniper Woodland Classification 

Using the three-level concept, a pinyon-juniper woodland 

site can be classified as follows: 

Pinyon-Utah Juniper Woodlands Type 

Level1-Pinyon-Utahjuniper mixed woodlands. 

Level 2-Pinyon-Utah juniper, black sagebrush 

(association). 

Level 3-Pinyon (PIED), Utah juniper (JUOS), black 

sagebrush (ARNO), western wheatgrass (AGSM), (plant 

community). 

Field Mapping and Plant Community Type Numbering 

Each community site was located on the ground and its 

boundaries delineated on the aerial photo. The site was then 

classified into its level of classification (woodland, association, or plant community), and a descriptive name was 

applied. 

Mapping Numbers 

For mapping purposes and ease of designating each plant 

community type, a numbering system was developed. (The 

pinyon-juniper type based on the old Range Survey and 

Range Analysis was designated as a "9" type. The number 

"9" is used as a prefix for coding all pinyon-juniper types in 

the study area.) 

The following woodland types, plant association, and 

plant communities were found within the study area. 

Woodland Types 

Map No. 

90 

91 

92 

93 

Map No. 

90 

91 

Type 

Pinyon-juniper (woodland) 

Utah juniper (woodland) 

Pinyon (woodland) 

Rocky Mountain juniper (woodland) 

Type 

Pinyon Utah juniper (woodland) 

This woodland type includes all sites where 

pinyon and Utah juniper occur in mixed stands. 

Tree composition may vary from 20 to 70 percent 

of either tree present on the site. It occurs mostly 

at the lower to mid elevations (6,000 to 7,500 ft), 

on rocky ridges, open bench lands, alluvial fans, 

and other slopes. 

Utah juniper (woodland) 

This woodland type is dominated by Utahjuniper 

(90 to 100 percent of the tree overstory is Utah 

juniper). It occurs mostly at the lower elevations 

61 
92 

93 

of the type (5,500 to 6,500 ft) and on rocky ridges, 

benchlands, and alluvial slope lands. 

Pinyon (woodland) 

This woodland type is domina ted by pinyon, with 

95 to 100 percent of the overstory being pinyon 

trees. It occurs at the mid to higher elevations of 

the woodland type (7,500 to 8,500 ft), on benchlands, mesa tops, and upper slope lands. 

Rocky Mountain juniper (woodland) 

This woodland type includes all of the sites 

dominated by Rocky Mountain juniper trees (50 

to 90 percent). Some pinyon may be present 

(5 to 20 percent), and at the lower elevations, 

some Utah juniper may be present (1 to 5 

percent). It occurs mostly at the mid elevations 

of the woodland type (7,000 to 8,000 ft), on 

benchlands and north slopes, along streams, 

and around some meadows and wet sites. 

Plant Association 

Map No. Type 

Pinyon-Utah juniper woodland plant association 

901 Pinyon-Utah juniper-black sagebrush 

902 Pinyon-Utah juniper-mountain big sagebrush 

903 Pinyon-Utah juniper-true mountainmahogany 

904 Pinyon-Utah juniper-bitterbrush 

905 Pinyon-Utah juniper-serviceberry/oakbrush 

906 Pinyon-Utah juniper-snowberry 

908 Pinyon-Utah juniper-roundleafbuffaloberry 

Utah juniper woodland plant association 

910 Utah juniper-black sagebrush 

Pinyon woodland plant association 

920 Pinyon-oakbrush 

921 Pinyon-serviceberry 

922 Pinyon-snowberry . 

923 Pinyon-mixed mountain brush 

Plant Communities 

Map No. Plant communities and habitats 

62 

901 Pinyon-Utah juniper-black sagebrush 

9010 Pinyon (PIED), Utahjuniper(JUOS), black 

sagebrush (ARNO), western wheatgrass 

(AGSM), Sandberg bluegrass (POSE) 

9011 Pinyon (PIED), Utahjuniper(JUOS), black 

sagebrush (ARNO), needlegrass (STCO), 

Indian ricegrass (ORHY) 

9013 Pinyon (PIED), Utah juniper (JUOS), black 

sagebrush (ARNO), blue grama grass 

(BOGR) 

9014 Pinyon (PIED), Utah juniper (JUOS), black 

sagebrush (ARNO), chained and reseeded 

9017 Pinyon (PIED), Utah juniper (JUOS), basin 

big sagebrush (ARTRW), squirreltail (SIHY) 

902 Pinyon-Utah juniper-mountain big sagebrush 

9020 Pinyon (PIED), Utah juniper (JUOS), big 

mountain sagebrush (ARTRV), western 

wheatgrass (AGSM) 

9023 Pinyon (PIED), Utah juniper (JUOS), 

mountain big sagebrush (ARTRV), 

needlegrass (STCO) 

9024 Pinyon (PIED), Utah juniper (JUOS), 

mountain big sagebrush (ARTRV), chained 

and reseeded (AGER, BRIN, AGIN) 

903 Pinyon (PIED), Utah juniper (JUOS), true 

mountainmahogany 

9032 Pinyon (PIED), Utah juniper (JUaS), true 

mountainmahogany (CEMO), needlegrass 

(STCO), Indian ricegrass (ORHY) 

9033 Pinyon (PIED), Utah juniper (JUaS), little 

leaf mahogany (CEIN), Rosses sedge 

(CARO), (slick rock) 

904 Pinyon (PIED)-Utah juniper (JUOS)-bitterbrush 

9040 Pinyon (PIED), Utah juniper (JUOS), bitter 

brush (PUTR), needlegrass (STCO), Indian 

ricegrass (0 RHY) 

9041 Pinyon (PIED), Utah juniper (JUOS), 

bitterbrush (PUTR), western wheatgrass 

(AGSM), Sandberg bluegrass (POSE) 

9042 Pinyon (PIED), Utah juniper (JUQS), 

bitterbrush (PUTR), western wheatgrass 

(AGSM) 

9043 Pinyon (PIED), Utah juniper (JUOS), 

bitterbrush (PUTR), chained and reseeded 

(AGCR, BRIN, AGIN) 

9044 Pinyon (PIED), Utah juniper (JUOS), 

bitterbrush (PUTR), cliff rose (COST), 

needlegrass (STCO), lichen 

908 Pinyon (PIED), Utah juniper (JUOS), roundleaf 

buffaloberry 

9081 Pinyon (PIED), Utah juniper (JUOS), 

roundleaf buffaloberry (SHRO), Sandberg 

bluegrass (POSE) 

USDA Forest Service Proceedings RMRS-P-9. 1999 
c 

(J) 

0 

» 

11 

0 

m 

!a. 

(J) 

CD 

< 

I / o· 

CD 

"1J 

a 

0 

CD 

CD 

a. 

s· 

<0 

en 

:0 

~ 

:0 

(J) 

I 

-b 

~ ~ G> <0 

<0 

<0 

9052 

1 o 

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50 

-~i[Q 9052 \ 

1 

Pinyon Juniper Plant Commun

(Sample Area) 

9056 Pinyon (PIED), Utah 

Brush Mixed grammanoid 

9052 Pinyon (PIED), Utah 

(AMAL), Ephreda (EPLI), San

9044 Pinyon (PIED), Utah 

(PUTR), Cliff rose (COST), Ne

9033 Pinyon (PIED), Utah 

mohogany(CIEN), Rosses Se

9023 Pinyon (PIED), Utah J

brush (ARTRV), Needlegrass 

9081 Pinyon (PIED), Utah 

buffaloberry (SHRO), Mixed M

(POSE) 

Other Plant Types 

o Barren 

40 Sagebrush 

62 Douglas Fir 

61 Ponderosa Pine 

50 Mtn. Brush 

90 Pinyon Juniper 

Data from MLNF 19

2 Miles 

~ Figure 1-Vegetative cover, South Cottonwood assessment area, Moab-Monticello Ranger Disrict, Manti-La Sal National Forest. 
Gradient Analysis of Pinyon-Juniper 

Woodland in a Southern Nevada Mountain 

Range 

Simon A. Lei 

Abstract-The environmental variables and distribution of 

singleleaf pinyon-Utah juniper woodland were examined along 

an elevational gradient in Lee Canyon of southern Nevada. 

TWINSP AN classification identified four primary species groups 

that were dominated by blackbrush, big sagebrush, singleleaf 

pinyon, and ponderosa pine, respectively, as elevation increased. 

DECORANA analysis indicated that the distribution of stand and 

species groups was strongly associated with elevation, soil moisture, air temperature, percent bare soil and rock cover, and soil 

depth. These attributes associated with changing elevation appeared to be important in organizing the current vegetation assemblages in southern Nevada. 

Creosote bush-bursage (Larrea tridentata-Ambrosia 

dumosa), blackbrush (Coleogyne ramosissima), singleleaf 

pinyon-Utah juniper (Pinus monophylla-Juniperus osteosperma), and ponderosa pine-white fir (Pinus ponderosaAbies con color) are four common vegetation types as elevation increases in southern Nevada. Previous studies in the 

mountain ranges of southern Utah and Nevada have been 

documented regarding changes in vegetation types that 

corresponded largely with abiotic factors (Beatley 1974; 

Bowns 1973; Bowns and West 1976; Turner 1982). Such 

factors include precipitation, soil moisture, soil depth, and 

air and soil temperatures. Soil moisture and cold winter air 

temperatures appear to control the distribution of pinyonjuniper trees at their lower and upper elevational boundaries, respectively, in Utah (Wright and others 1979). Shallow soils are typical of blackbrush shrublands due to the 

presence of caliche layers, and may partially determine the 

distribution and abundance of blackbrush shrubs in Utah 

(Callison and Brotherson 1985). Decreased air and soil 

temperatures, increased precipitation, and increased soil 

moisture were strongly associated with increasing elevation 

in the Spring Mountains (Lei and Walker 1995, 1997a,b). 

However, other abiotic factors that potentially influence the 

distribution of pinyon-juniper woodlands in southern Nevada are not properly understood. 

In this study, elevation was designed to determine 

which abiotic factors change with changing elevation. The 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Simon A. Lei is a Professor of Biology and Ecology at the Community 

College of Southern Nevada, 6375 West Charleston Boulevard, W2B, 

Las Vegas, NV 89102-1124. 

64 

objectives of this study were (1) to calculate relative density 

of woody perennial species, (2) to classify vegetation types, 

and (3) to investigate the relationships between stand and 

species groups and environmental variables. Examining 

environmental parameters help elicit the ecological requirements of woody plant species and the specific environment they occupy in a current pinyon-juniper vegetation 

zone in southern Nevada. 

Methods _________ _ 

Study Site 

The study was conducted in Lee Canyon (roughly 36°05' N, 

115°45' W), located 50 km northwest of Las Vegas, Nevada, 

on the east-facing slope of the Spring Mountains. The temperature and precipitation data were obtained from the 

nearest long-term weather station (record of climatological 

observations; National Weather Service) in Kyle Canyon, 

located approximately 15 km from Lee Canyon. Lee Canyon 

is an area of temperature extremes with a mean minimum 

January temperatures of -12°C ranging to 26°C for a 

mean July maximum. Winter months are frigid, often associated with strong winds, whereas summer months are cool 

with air temperatures rarely surpass 32 °C. 

The Precipitation patterns include summer storms and 

winter rains. Summer storms and rainfalls generally occur 

in July and August, and can sometimes be locally intense. 

Winter rainfalls tend to be mild, and may last several days. 

Snow is frequent at high elevations. Winter precipitation 

contributes significantly to the annual precipitation, which 

ranges from 300 to over 600 mm in the ponderosa-fir woodland, and usually less than 400 mm in the pinyon-juniper 

woodland. 

The bajada consists of benches interspersed by dry 

washes, which become more abundant and shallow when 

moving down slope near the bottom of the canyon. A nearly 

mono specific blackbrush shrubland occurs at mid-elevations on well-drained colluvial slopes. Caliche outcroppings 

are evident along the banks of washes on the bajada of 

the blackbrush zones. A pinyon-juniper woodland exists 

above the blackbrush shrublands, and a montane ponderosa 

pine-white fir forest occurs above the pinyon-juniper zone on 

relatively high mountain slopes in Lee Canyon. 

Field Surveys 

Vegetation and soil measurements were conducted at 

Lee Canyon in the Spring Mountains during the summer of 

1996. An elevational gradient was established that began in 

USDA Forest Service Proceedings RMRS-P-9. 1999 
the upper portion of the blackbrush shrubland, crossed the 

entire pinyon-juniper belt, and terminated in the lower 

portion of the montane ponderosa pine-white fir forest. 

Five 200-m2 (8.0 m radius) circular stands (plots) were 

established at 18 sample points, located at 65-m elevation 

increments between 1,700 and 2,600 m. The total elevational 

change was 900 m and 90 stands were measured. Topographies ofthe transect included bench terraces, hill slopes, and 

dry washes. However, when cliff and stream bed sites were 

encountered, a substitute stand was placed approximately 

50 m from the original transect at the identical elevation. 

Within each stand, all woody perennial plant species 

(>10 cm tall), including subshrubs (suffrutescent), were 

identified (Munz 1974) and counted. Elevation and aspect 

of each plot were recorded using an altimeter and a compass, respectively. Soil depth to hardpan was estimated by 

striking a steel rod into the undisturbed soils until the rod 

could no longer penetrate. Soil depth was estimated by 

averaging 10 random samples within each stand. Gravimetric soil moisture was determined by calculating the 

differences between the fresh and oven-dried mass. Air 

temperatures at 1.5 m above ground were recorded. The 

ground surface of each stand was characterized as cemented 

or non-cemented desert pavement, loose rocks, sandy, or 

sandy with boulders. Percent soil and rock cover were 

visually quantified, and were assigned a cover class using 

the following scales: 0 = <1 percent; 1 = 1-5 percent, 2 = 6-

25 percent, 3 = 26-50 percent, 4 = 51-76 percent, and 5 = 76-

100 percent. Each circular stand was located at least 50 m 

away from any main and secondary roads to eliminate 

direct and indirect road effects. 

Statistical Analyses 

Classification and ordination techniques were applied 

from the 90 sampled stands in Lee Canyon. The relative 

density of each species was calculated for each stand by 

dividing the number of individuals of a species by the total 

number of individuals, and multiplying by 100 (MullerDombois and Ellenberg 1974). Each species relative density 

was entered into a species-stand matrix and classified with 

TWINS PAN (Hill 1979a), a divisive hierarchical classification technique that yields a two-way classification of species 

and stands. The dichotomy was terminated when a group 

consisted of four or fewer plots (Kent and Coker 1992). 

For each sample location, the species relative densities 

and the environmental variables were ordinated with 

DECORANA (Hill 1979b), a method utilized for defining the 

environmental gradients within a set of vegetation data. 

The species relative densities were also subjected to 

DECORANA analysis that generated stand and species 

ordination diagrams where each point represented a stand 

and a species, respectively. Environmental parameters at 

each sample location included elevation, stand aspect, topography, soil depth, type of ground surface, as well as 

percent bare soil and rock cover. Each environmental parameter was then matched with axes 1 and 2 of the stand 

ordination scores acquired from DECORANA to determine 

correlations between stand groups and environmental factors (Analytical Software 1994). 

Results __________ _ 

Desert vegetation at upper elevations in Lee Canyon of 

the Spring Mountains consisted of 33 woody perennial 

species. The TWINSPAN classification suggested that 

these 33 species were organized into four primary species 

groups along the elevational gradient at Lee Canyon of 

southern Nevada (fig. 1; table 1). 

Species in grou p A were typical of monospecific blackbrush 

vegetation zone. Joshua tree, turpentine bush (Thamnosma 

LEE CANYON 

1.0 

EIGENVALUE 

A 

CORA: 

MESP 

TEAX 

THMO 

USDA Forest Service Proceedings RMRS-P-9. 1999 

ARTR 

EPVI 

GUSA 

YUBA 

B 

CELA: ATCA 

GACO CEGR 

CHNA 

COME 

OPBA 

SPECIES GROUPS 

C 

ABCO 

PIFL 

PIPO 

POTR 

Figure 1-Dendrogram of 

TWINSPAN analysis of 33 woody 

taxa surveyed in Lee Canyon of 

the Spring Mountains. The four 

major species groups are segregated by brackets, and are arranged from the lowest (Group A) 

to the highest (Group D) 

elevational groups. Species within 

each group are arranged alphabetically. Species abbreviations 

corresponded to the first two letters of the genus and species 

listed in table 1. 

65 
Table 1-Woody and suffrutescent taxa establishing at Lee 

Canyon of the Spring Mountains. Symbols of lifeforms: 

T = Tree; S = Shrub; Ss = Subshrub (suffrutescent); 

and Su = Succulent. 

Species Lifeform Abbreviation 

Abies conc%r T ABCO 

Artemisia tridentata S ARTR 

Atrip/ex canescens S ATCA 

Ceanothus greggii S CEGR 

Ceratoides /anata S CELA 

Cercocarpus /edifolius T CELE 

Chrysothamnus nauseosus S CHNA 

Co/eogyne ramosissima S CORA 

Cowania mexicana S COME 

Ephedra nevadensis S EPNE 

Ephedra viridis S EPVI 

Fallugia paradoxa S FAPA 

Gaura Coccinea S GACO 

Gutierrezia sarothrae Ss GUSA 

Juniperus osteosperma T JUOS 

Lycium andersonii S LYAN 

Menodora spinescens S MESP 

Mirabilis froebe/ii S MIFR 

Opuntia acanthocarpa Su OPAC 

Opuntia basilaris Su OPBA 

Opuntia echinocarpa Su OPEC 

Opuntia ramosissima Su OPRA 

Pinus flexi/is T PIFL 

Pinus monophylla T PIMO 

Pinus ponderosa T PIPO 

Populus tremu/oides T POTR 

Psorothamnus fremontii S PSFR 

Sa/azaria mexicana S SAME 

Tetradymia axil/aris S TEAX 

Thamnosma montana S THMO 

Yucca baccata S YUBA 

Yucca brevifo/ia T YUBR 

montana), and Mormon tea (Ephedra nevadensis) were 

some of the common associated species occurring at midelevation (fig. 1). Species in group B were typical of lower 

pinyon-juniper ecotone (fig. 1), with big sagebrush (Artemisia tridentata) as the dominant species in terms of density 

and total vegetation cover. Big sagebrush became less abundant and were an understory shrub in the pinyon-juniper 

woodland. Species in group C were characterized by pinyonjuniper woodland, with singleleafpinyon as the most abundant species (fig. 1). Pinyon-juniper woodland often shared 

a relatively broad lower ecotone with blackbrush. Species in 

group D were characterized by montane ponderosa-fir forest, and were established on desert mountain slopes at high 

elevations above the pinyon-juniper woodland. Limber pine 

(Pinus flexilis) and quaking aspen (Populus tremuloides) 

were the representative species (fig. 1). 

The DECORANAordination of the 90 stands on axes 1 and 

2 is shown in figure 2, and revealed the distribution of the 

four TWINSPAN-based vegetation types. The DECORANA 

analysis detected a significant stand group segregation 

along axis 1, but not along axis 2 (fig. 2), Results of Pearson's 

correlation analysis (table 2) showed that axis 1 of the stand 

ordination was significantly correlated with elevation, soil 

moisture, air temperature, percent bare soil, percent rock 

cover, and soil depth in descending order of significance. 

However, axis 2 was not significantly correlated with any 

66 

LEE CANYON. STANDS 

400 I 

I 

'-' GROUP 1 :0 300:-- 0 • 0 • • • GROUP 2 

io • • GROllP 3 0J '0 0 0 • 0 

:,.0 c:P x • GROUP 4 ~cP 0·. • « 2CJ « 

u a • • Cl • • • • 0 CJ • 100 • a :. 

. .~ CJ • • • • .. I 0 0 • 

c 

0 200 400 600 800 

DCA AXIS· 

Figure 2-DECORANA ordination of 90 stands in Lee 

Canyon of the Spring Mountains. Different symbols 

represent major groups delimited by TWINSPAN. 

Axis 1 of the stand ordination was significantly correlated with elevation, soil moisture, air temperature, 

percent bare soil and rock cover, and soil depth. Some 

points were eliminated to aid visualization. 

environmental variables (table 2). Ordination of the four 

TWINSPAN-based species groups and individual species on 

axes 1 and 2 is illustrated in figure 3, showing that different 

plant species occupied different elevations and vegetation 

zones in southern Nevada. 

Discussion __________ _ 

Significant correlations between the distribution of 

plant communities and environmental variables were detected at Lee Canyon of the Spring Mountains in southern 

Nevada. Blackbrush, big sagebrush, singleleafpinyon, and 

Table 2-Pearson's correlation coefficient (r-value) corresponding with the first and second axes of stand 

ordination scores acquired from DECORANA to 

various environmental factors. r-values were determined from the analysis of 90 sampled stands 

located at Lee Canyon of the Spring Mountains. 

Significance levels: *: p < 0.05; **: p < 0.01; ***: 

p < 0.001, and NS: Non-Significant. 

Factor 

Elevation 

Soil moisture 

Air temperature 

Percent soil cover 

Percent rock cover 

Soil depth 

Ground surface 

Topography 

Plot aspect 

Axis 1 Axis 2 

- - - - - - - -" -r- - -- - - - - --- -0.9T" -0.04NS 

0.95'" 0.16NS 

-0.89'" -0.08NS 

0.81'" -0.12NS 

-0.85'" 0.09NS 

0.83'" -0.06NS 

-0.37NS -0.29NS 

-O.17NS -0.38NS 

::;0.01 NS -0.42NS 

USDA Forest Service Proceedings RMRS-P-9. 1999 
ponderosa pine were the strong indicators of the species 

groups A, B, C, and D, respectively, distributed along a 

gradient of increasing elevation. The most important environmental factors associated with the distribution of stand 

and species groups were elevation, soil moisture, air temperature, percent bare soil and percent rock cover, and soil 

depth, in descending order of significance. 

TWINSP AN results revealed a major dichotomy between 

high and low elevation communities, with each community 

splitting into two elevational phases. The first TWINSPAN 

dichotomy segregated low elevational communities, with a 

high abundance of blackbrush and big sagebrush shrubs, 

from high elevational communities, with pinyon-juniper 

and ponderosa-fir trees (fig. 1). Precipitation and soil moisture are positively correlated with elevation, while air and 

soil temperatures are negatively correlated with elevation 

(Lei and Walker 1997b). The first dichotomy within species 

groups A and B separated species generally existing in the 

big sagebrush stands (upper blackbrush ecotone) from the 

nearly monospecific blackbrush vegetation, which had an 

increase in soil moisture and soil organic matter and a 

decrease in soil compaction and soil temperatures (Lei and 

Walker 1997b). 

Species in group B were characterized by big sagebrush 

shrubs with snakeweed (Gutierrezia sarothrae) as the most 

common associated species (fig. 1). Although Joshua tree 

may occur in abundance with creosote bush or Utah juniper, it frequently coexists with blackbrush in the Mojave 

Desert (Turner 1982). The dominance of Joshua tree is more 

visual than real and contributes little to the total stand 

composition and vegetation cover (Turner 1982). 

The second TWINSP AN dichotomy segregated species 

existing at the upper blackbrush ecotone (group C) from 

those existing at higher elevations (group D; fig. 1). 

Blackbrush vegetation zones often form relatively broad 

upper ecotones. Singleleaf pinyon was the most abundant 

species in group C, and frequently establishes above the 

upper blackbrush ecotones in southern Nevada. Species in 

group D (fig. 1) were typical of high mountain slope vegetation with frigid winter air temperatures accompanied by 

relatively strong winds. Precipitation is usually in the form 

of snow, which can remain on the ground for extended 

periods in the winter and early spring (Turner 1982). 

Axes 1 and 2 of the DECORANA stand and species 

ordination (figs. 2 and 3, respectively) were used to generate 

hypotheses in identifying probable environmental attributes on the distribution ofindividual stands and species. 

DECORANA ordination of the 90 sampled stands (fig. 2) 

revealed a significant stand group segregation along axis 1 

only. Zonation of woody desert vegetation with respect to 

elevation is conspicuous in Lee Canyon. Environmental 

attributes, such as temperature, precipitation, and associated 

soil development processes, are important in organizing 

the final groupings of stands and species. Ecological attributes associated with changing elevation largely determine species distribution and vegetation associations. 

Soil depth declined at mid-elevations and was typical 

blackbrush zones (Lei and Walker 1997a and b). The greatest root biomass in these shrubland is located between 10 to 

30 cm (Bowns 1973). The low root:shoot ratio is related to 

shallow soil depth, impeding by the presence of caliche 

layers (West 1983). Soil depth began to increase at the upper 

USDA Forest Service Proceedings RMRS-P-9. 1999 

blackbrush ecotone and increased considerably in each of 

the two vegetation zones above blackbrush (Lei and Walker 

1997a). Hence, shallowness of soils appeared to be an important feature of the blackbrush zones and may partially 

determine the presence and absence of black brush shrubs in 

southern Nevada (Callison and Brotherson 1985; Lei and 

Walker 1997a,b). Shallow soils do not store abundant water, 

and more water is stored in deeper soils which can support 

relatively large trees, such as limber pine, ponderosa pine, 

and white fir. Soil texture, air temperatures, and precipitation patterns are also an important influence on soil moisture storage. Persistent snow cover at higher elevation and 

slow melt later into the spring can lengthen the period of 

recharge and provide more soil water, which can permit 

larger and more productive individuals or species. 

The percent bare soil cover generally increased with 

elevation, while the percent rock cover decreased with elevation in Lee Canyon. Percent bare soil and rock cover are not 

likely to be causal agents in the vegetational mosaic. They 

are probably the consequence of vegetation cover, rather 

than a cause for vegetation patterns. Moreover, dense 

woodland vegetation normally does not establish well with 

abundant rocks on the soil surface (Lei 1994, 1995). Nevertheless, limited small pockets of soft materials may exist 

among the rock fragments where seedlings may grow and 

survive (Lei 1994, 1995). 

Implications and Future 

Directions --------------------------------- The results of classification and ordination analyses using 

vegetation and environmental data from Lee Canyon support previous studies in Utah and southern Nevada that 

certain abiotic factors limit the distribution of vegetation 

t"\j 

Vl 

x 

-< 

-< 

0 

c 

LEE CA'JYON, SPECIES 

600 r---...,Ic---.-------.---'I--,---1-..... 

400 

200 

0 

OPRA 

o 

:'YAN GUSA 

ECPO C • Q CEGR 

cO PSF'R 

EPNE 

• EPVI 

A~TR • 

Yl:BA • 

YUBR 

GACO 

• 

PIFL 

• Pl)JO 

o o ;UOS o MESP 

o~ CORA 0 

TE~~ C 0 

o B ~~~: ceME 

THMO 

MIFR 

o 

POTR 

: ABCO 

PIPO 

-200 L---_~ _ ___I. __ ..L._ __ __L. ___ ~ _ ____' 

-200 0 200 400 600 BOO 1000 

DCA AXIS 1 

Figure 3-DECORANA ordination of 33 species in Lee 

Canyon of the Spring Mountains. Different symbols represent major groups delimited by TWINSPAN. Species 

abbreviations are corresponded to the first two letters of 

the genus and species listed in table 1 . 

o GROUP A 

• GROUP B 

CJ GROUP C 

• GROUP D 

67 
zones (Beatley 1974; Bowns and West 1976). Plant assemblages in Lee Canyon may be representative of vegetation 

and landscape conditions at high mountain slopes throughout southern Nevada. However, relationships between environmental factors and the distribution of species are strictly 

correlative. Correlation between two variables does not 

necessary mean that a cause-effect relationship exists between them. Understanding additional ecological attributes 

or processes are essential for developing a local model that 

can accurately predict species and community distribution 

and abundance. Establishment oflong-term plots, as well as 

experimental, physiological, and ecosystem approaches are 

necessary to determine cause-effect relationships between 

the distribution ofthe Mojave Desert plant communities and 

associated abiotic factors in southern Nevada. 

Acknowledgments 

I gratefully acknowledge Yin-Chin Lei, Steven Lei, David 

Valenzuela, and Shevaum Valenzuela for collecting vegetation and environmental data. Critical review of the 

manuscript by John Bolling and Leslie Thomas is deeply 

appreciated. 

References ---------------------------------- Analytical Software. 1994. Statistix 4.1, an interactive statistical 

program for microcomputers. Analytical Software. 329 p. 

Beatley, J. C. 1974. Effects of rainfall and temperature on the 

distribution and behavior of Larrea tridentata (creosote-bush) in 

the Mojave Desert of Nevada. Ecology. 55: 245-261. 

Bowns, J. E. 1973. An autecological study of blackbrush 

(Coleogyne ramosissima Torr.) in southwestern Utah. Unpublished dissertation, Utah State Univ., Logan, Utah. 

Bowns, J. E. and N. E. West. 1976. Blackbrush (Coleogyne 

ramosissima Torr.) on southern Utah rangelands. Department 

of Range Science, Utah State University. Utah Agricultural 

Experimental Station, Research report 27. 

Callison, J. and J. D. Brotherson. 1985. Habitat relationship of 

the blackbrush community (Coleogyne ramosissima) of southern 

Utah. Great Basin Naturalist 45:321-326. 

68 

Hill, M. O. 1979a. TWINSPAN: A Fortran program for arranging 

multivariate data in an ordered two-way table by classification of 

individuals and attributes. Ecology and Systematics, Cornell 

University, Ithaca, New York. 

Hill, M. O. 1979b. DECORANA: A Fortran program for detrended 

correspondence analysis and reciprocal averaging. Ecology and 

Systematics, Cornell University, Ithaca, New York. 

Kent, M. and P. Coker. 1992. Vegetation description and analysis: 

a practical approach. Belhaven Press, London, United Kingdom. 

363 p. 

Lei, S. A 1994. Plants of the North American desert~. Unpublished 

research report, University of Nevada, Las Vegas. 

Lei, S. A 1995. A gradient analysis of Coleogyne ramosissima 

communities in southern Nevada. Unpublished master's thesis, 

University of Nevada, Las Vegas. 

Lei, S. A and L. R. Walker. 1995. Classification and ordination of 

Coleogyne communities in southern Nevada. Abstract of the 80th 

Annual Ecological Society of American Meeting. 158 p. 

Lei, S. A and L. R. Walker. 1997a. Classification and ordination 

of Coleogyne (blackbrush) communities in southern Nevada. 

Great Basin Naturalist. 57: 155-162. 

Lei, S. A and L. R. Walker. 1997b. Biotic and abiotic factors 

influencing the distribution ofColeogyne communities in southern Nevada. Great Basin Naturalist. 57: 163-171. 

Muller-Dombois, D. and H. Ellenberg. 1974. Aims and Methods of 

Vegetation Ecology. John Wiley and Sons, New York. 547 p. 

Munz, P.A 1974. A flora of Southern California. University of 

California Press, Berkeley, California. 1086 p. 

Smith, S. D.; [and othersl. 1995. Structure of woody riparian 

vegetation in Great Basin National Park. In: Roundy, Bruce A; 

McArthur, E. Durant; Haley,JenniferS.; Mann, David K., comps. 

1995. Proceedings: Wildland Shrub and Arid Land Restoration 

symposium; 1993 October 19-21; Las Vegas, NV. Gen. Tech. Rep. 

INT-GTR-315. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 246-251. 

Turner, R. M. 1982. Biotic communities of the American southwest-United States and Mexico. Geological Survey, U.S. Department of the Interior. 

West, N. E. 1983. Colorado plateau-Mohavian blackbrush semidesert. In: Temperate desert and semi-deserts. Elsevier Scientific 

Publishing Company, Amsterdam, Netherlands: 399-411. 

Wright, H. A.; 1. F. Neuenschwander, and C. M. Britton. 1979. 

The role and use of fire in sagebrush-grass and pinyon-juniper 

plant communities. USDA Forest Service. Gen. Tech. Rep. 

INT-58. Intermountain Forest and Range Experiment Station, Ogden, Utah. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Cheatgrass Frequency at Two Relic Sites 

Within the Pinyon-Juniper Belt of Red 

Canyon 

Sherel Goodrich 

Natalie Gale 

Abstract-Frequency of cheatgrass (Bromus tectorum) is reported 

for two relic sites within a belt of Colorado pinyon (Pinus edulis) 

and Utah juniper (Juniperus osteosperma), where non-Native 

Americans and their livestock are likely_ to have had little effect. 

Young and Tipton (1990) suggested the concept of 

cheatgrass spreading in a biological vacuum created by 

grazing may be somewhat misleading or overstated, and 

they cited two works from Washington that documented 

observations of cheatgrass successfully inserting itself into 

climax perennial grass/shrub communities that had been 

protected from fire and grazing for as long as 50 years. 

While livestock grazing is a factor in the spread of cheatgrass, 

other works collaborate the idea that livestock grazing and 

other human-induced disturbance are not the only factors. 

Kindschy (1994) reported the presence and increase of 

cheatgrass in southeastern Oregon's Jordan Crater Research Natural Area that has been protected from human 

activities including livestock grazing. Tausch and others 

(1994) found cheatgrass has displaced native perennial 

species on Anaho Island in Nevada despite a general absence of human-caused disturbance and fire. They attributed the increase to the competitive ability of cheatgrass. 

Knight (1994) reported the cheatgrass problem is not restricted to land managed for livestock, and he gave an 

example of an increase of cheatgrass following fire in Little 

Bighorn Battlefield National Monument in southern Montana. He suggested that managing vegetation of aN ational 

Monument so it reflects pre settlement conditions is a goal 

that may be impossible once certain introduced species 

become established. 

The sites of this study are located within a belt of 

Colorado pinyon (Pinus edulis) and Utahj uni per (Juniperus 

osteosperma) within the Green River corridor, Daggett 

County, Utah. They are located on steep, warm exposures 

within Red Canyon above the Flaming Gorge Reservoir at 

about 1,890 to 1,950 m (6,200-6,400 ft) elevation and about 

9.7 km (6 miles) west of Dutch John, UT, where data from 

the Flaming Gorge Weather Station indicates mean 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Sherel Goodrich is Forest Ecologist, Ashley National Forest, Forest Service, U.S. Department of Agriculture, Vernal, UT 84078. Natalie Gale is a 

Natural Resource Consultant, Minnies Gap, WY. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

annual precipitation for the area of 31.75 cm (12.50 

inches) (Ashcroft and others 1992). 

In the Bare (Bear) Mountain area of the Green River 

corridor, Smith (1992) and Greenwood and others (these 

proceedings) found older pinyon-juniper burns were highly 

preferred by bighorn sheep (Ovis canadensis). In these 

studies, bighorn sheep were also found to frequently use 

areas where fire (including recent fire) kept pinyon and 

juniper at low levels. However, these workers also found 

the sheep avoided moderate or dense stands of pinyonjuniper, and recent burns in dense stands ofpinyon-juniper 

where tree skeletons were still standing. Radio monitored 

sheep were found repeatedly in a pinyon-juniper burn site 

(Site 5-26) in which size and growth form of the trees that 

established since the fire indicate the burn to have been 

about 80 years old. Trees at the site were small and 

scattered and the site was dominated by grasses. Another 

site, which apparently had not been burned in the past 150 

years or more, had open tree cover (Site 5-18), and it was 

also used by bighorn sheep in preference to surrounding 

areas with greater canopy cover of pinyon-juniper. Rock 

debris covered about 50 percent of both sites, which were 

located below massive cliffs. These sites were visited in 

1988 and 1991 to monitor forage conditions in relation to 

bighorn sheep. The bighorn sheep herd is not expected to 

have played an important role in plant community dynamics and composition since this was a transplanted herd of 

1983 and 1984. 

Domestic livestock use is expected to have been minimal 

as the sites were protected by massive cliffs and steep 

slopes. The sites are within a large area that has been 

closed to permitted livestock grazing since the early 1960's. 

Methods and Results 

Frequency of plant species was determined in 100 quadrats of 50 by 50 cm at intervals of1.5 m (5 ft) along five belts 

of which each was 30.5 m (100 ft) long. Within these 

quadrats, presence of species was recorded in nested frequency plots of 5 by 5 cm, 25 by 25 cm, and 25 by 50 cm as 

well as the 50 by 50 cm quadrat. 

Table 1 shows quadrat frequency and nested frequency 

values. Sampling methods are those outlined by U.S. Department of Agriculture, Forest Service (1993) in which 

each species has a potential nested frequency score of 400. 

Other species oflow frequency (not listed in table 1) were 

also found on the sites. Ground cover was also determined 

by a point method that indicated 54 percent of the surface 

was covered by rock at both sites. Ground cover provided by 

vegetation and litter was about 30 percent at both sites, and 

69 
Table 1-Quadrat frequency percent (QF) and nested frequency (NF) score based on a potential 

score of 400. 

Species 

Cheatgrass (Bromus tectorum) 

Bluebunch wheatgrass (E/ymus spicatus) 

Hairy goldenaster (Heterotheca vil/osa) 

Louisiana wormwood (Artemisia /udoviciana) 

Brickellbush (Brickellia scabra) 

Plains mustard (Schoencrambe linifolia) 

Muttongrass (Poa fend/eriana) 

Prickleypear (Opuntia sp.) 

Tansy-mustard (Descurainia pinnata) 

Broom snakeweed (Gutierrezia sarothrae) 

Fringed sagebrush (Artemisia frigida) 

Needle-and-thread grass (Stipa comata) 

Sanddrop seed (Sporobo/us cryptandrus) 

Yellow-eye cryptanth (Cryptantha flavocu/ata) 

Indian ricegrass (Stipa hymenoides) 

Bottlebrush squirreltail (E/ymus e/ymoides) 

Black sagebrush (Artemisia nova) 

Big sagebrush (Artemisia tridentata) 

15 to 20 percent of both sites showed exposed soil and 

pavement (gravel fragments less than 2 cm or 0.75 inches 

in diameter). 

Discussion __________ _ 

Cheatgrass was by far the most frequent species at both 

study sites. Its high frequency indicates its high capacity to 

drive plant community dynamics for many years following 

fire in the pinyon-juniper belt on steep, south-facing, rocky 

slopes of Red Canyon in the absence of livestock and with 

little use by humans. It was also found with high capacity 

for spreading into areas without post-European settlement 

fires on these steep slopes. Bighorn sheep were known from 

the area in the past (Smith 1992), and presence of bighorns 

on the site represents use that predates European settlement. However, these sheep had been extirpated from the 

area for many years. The current presence of bighorn sheep 

is a function ofa transplant ofless than 10 years prior to the 

data taken from these sites. Little community change is 

expected from this use. 

The introduction of cheat grass to the American continent 

is a function of human activity. However, non-Native American influence has been low at these specific sites. The 

ability of cheatgrass to drive plant community dynamics 

where human and domestic livestock activities have been 

low is vividly demonstrated in Red Canyon. 

Management Implications ___ _ 

Within the past century, cheatgrass has become one of 

the most poten t ecological forces in parts of the West. Peters 

and Bunting (1994) have suggested the introduction of 

exotic annual grasses including cheatgrass into the Snake 

River Plain in Idaho may have been the most important 

event in the natural history of that region since the last 

glacial period. Catastrophic ecosystem change for the 

70 

Site 5-26 Site 5-18 

OF% NF Score OF% NF Score 

94 286 67 143 

53 110 2 6 

39 89 

23 50 

13 19 

8 19 

8 18 

7 16 

12 16 2 5 

4 12 6 14 

5 11 

5 11 

3 5 3 

5 9 

1 1 3 8 

3 9 

4 10 

5 9 

western Great Basin has been suggested by Billings (1994) 

as function of cheatgrass. Spread of this plant is often 

associated with disturbance by humans. However, it has 

inserted itself into and has dominated communities without human disturbance. 

Cheatgrass can be expected to be a major ecological force 

within its ecological amplitude, which includes some cold 

desert shrub, many sagebrush, pinyon-juniper, and mountain brush communities. Its influence is accelerated by 

disturbance. However, disturbance is often a matter of 

"when" more than a matter of "if." Management goals that 

do not include potential for disturbance are not realistic in 

many ecological settings. 

The concept of potential natural communities based only 

on native species is seriously challenged by cheatgrass. 

With reference to cheatgrass, Knight (1994) suggested: 

"Managing vegetation so it reflects pre settlement conditions is a goal that may be impossible once certain introduced species become established." The status of cheatgrass 

in Red Canyon and the reports in the literature cited in this 

text collaborate Knight's suggestion. Where cheatgrass is 

highly adapted, it might have to be recognized within 

potential. Refusing to do so will not red uce its presence, and 

this will not reduce its potential for dominance. 

However, the concept that preservation of native plant 

communities will prevent, eliminate, or control cheatgrass 

often prevails in planning, management, and legal maneuvering dealing with cheatgrass prone rangelands. Dynamics of plant communities of warm exposures in Red Canyon 

do not support this concept, and there seems to be little in 

literature dealing with cheatgrass to support this concept. 

References _________________ __ 

Ashcroft, G. L.; Jensen, D. T.; Brown, J. L. 1992. Utah climate. 

Logan, UT: Utah State University, Utah Climate Center. 125 p. 

Billings, W. D. 1994. Ecological impacts of cheatgrass and resultant 

fire on ecosystems in the western Great Basin. In: Monsen, S. B.; 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Kitchen, S. G., compilers. Proceedings-ecology and management of annual rangelands; 1992 May 18-21; Boise, ID. Gen. 

Tech. Rep. INT-313. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station: 22-30. 

Greenwood, C.; Goodrich, S.; Lytle, J. These proceedings. Response 

of bighorn sheep to burning in the Green River corridor, Daggett 

County, Utah. In: Monsen, Stephen B.; Stevens, Richard; Tausch, 

Robin J.; Miller, Rick; Goodrich, Sherel, comps. 1998. Proceedings: ecology and management of pinyon-juniper communities 

within the Interior West: 199715-18; Provo, UT. Proc. RMRSP-ooo. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 

Kindschy, R. R. (1994). Pristine vegetation of the Jordan Crater 

Kipukas: 1978-91. In: Monsen, S. B.; Kitchen, S. G., compilers. 

Proceedings-ecology and management of annual rangelands; 

1992 May 18-21; Boise, ID. Gen. Tech. Rep. INT-313. Ogden, UT: 

U.S. Department of Agriculture, Forest Service, Intermountain 

Research Station: 85-88. 

Knight, D. H. 1994. Mountains and plains: the ecology of Wyoming 

landscapes. New Haven, Conn., Yale University Press. 338 p. 

Peters, E. F.; Bunting, S. C. 1994. Fire conditions pre- and postoccurrence of annual grasses on the Snake River Plain. In: 

Monsen, S. B.; Kitchen, S. G., compilers. Proceedings-ecology and 

management of annual rangelands; 1992 May 18-21; Boise, ID. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Gen. Tech. Rep. INT-313. Ogden, UT: U.S. DepartmentofAgriculture, Forest Service, Intermountain Research Station: 31-36. 

Smith, T. S. 1992. The bighorn sheep of Bear Mountain: ecological 

investigations and management recommendations. Provo, UT: 

Brigham Young University. 425 p. Dissertation. 

Tausch, R. J.; Svejcar, T.; Burkhardt, J. W. 1994. Patterns of annual 

grass dominance on Anaho Island: implications for Great Basin 

vegetation management. In: Monsen, S. B.; Kitchen, S. G., compilers. Proceedings-ecology and management of annual rangelands; 1992 May 18-21; Boise, ID. Gen. Tech. Rep. INT-313. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 120-125. 

U. S. Department of Agriculture, Forest Service. 1993. Rangeland 

ecosystem analysis and management handbook. FSH 2209-21. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Region. 4 ch. 

Young, J. A.; Tipton, F. 1990. Invasion of cheatgrass into arid 

environments of the Lahontan Basin. In: McArthur, E. D.; Romney, E. M.; Smith, S. D.; Tueller, P. T., compilers. Proceedingssymposium on cheatgrass invasion, shrub die-off, and other 

aspects of shrub biology and management; 1989 April 5-7; Las 

Vegas, NV. Gen. Tech. Rep. INT-276. Ogden, UT: U. S. Department of Agriculture, Forest Service, Intermountain Research 

Station: 37-40. 

71 
A Comparison of Understory Species at 

Three Densities in a Pinyon-Juniper 

Woodland 

Darren Naillon 

Kelly Memmott 

Stephen B. Monsen 

Abstract-The relationship between pinyon-juniper density and 

associated understory were examined at three sites at Pigeon 

Hollow north of Ephraim, UT. Historically the study site was 

grazed from the turn of the century to -the 1980's when Utah 

Division of Wildlife Resources acquired the land. The area has 

since been used as critical winter range for wildlife with little 

livestock grazing, except for some trespass. All sites were north 

facing with 4 percent slope. Tree canopy cover was compared across 

three tree densities. Frequency and percent cover were reported 

across a gradient of pinyon-juniper densities. As pinyon-juniper 

tree density increases, associated understory and interspace herbaceous percent cover and diversity decreases. Decrease of perennial 

grasses amid tree interspaces was as significant as beneath tree 

canopy. 

The pinyon-juniper forest complex is an important component of the vegetation of the Intermountain West. This 

forest complex is mainly comprised of two leaf pinyon pine 

(Pinus edulis [Engelm.]), Utah juniper (Juniperus osteosperma [Torr.])~ one seed juniper (Juniperus monosperma 

[Engelm.]), and Rocky Mountain juniper (Juniperus scopulorum [Sarg.]). This community complex provides the 

majority wintering range for big game and associated animals in Utah (Stevens and Walker 1996). The pinyonjuniper woodlands comprise nearly 25 million ha (62 million 

acres) throughout the western United States (West 1986). 

Since settlement of the Great Basin, pinyon-juniper has 

expanded its range from steeper mountain slopes to alluvial 

fans and steppes. Increase of pinyon -j uni per is primarily due 

to suppression of fires and overgrazing by livestock during 

the last 100 to 150 years. Cottam (1961) reported western 

Utah's pinyon-juniper woodlands were among the most 

heavily impacted by domestic livestock during the period 

following settlement in the 1800's. The increased acreage of 

pinyon-juniper has led to problems in watershed management, loss of big game habitat, and reduced plant diversity. 

As the trees obtain dominance the remaining understory is 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Darren N aillon and Kelly Memmott are Ecologists, and Stephen B. Monsen 

is Botanist, Shrub Sciences Laboratory, Rocky Mountain Research Station, 

Forest Service, U.S. Department of Agriculture, Provo, UT 84606. 

72 

severely reduced (Dye and others 1995). Pinyon-juniper 

trees influence other plants in several ways: shading, litter 

accumulation under the tree canopy, interception and retention of rainfall by the branches and by the root system in the 

interspaces, and the development of an extensive, shallow, 

competitive root system (Schott and Pieper 1985). Junipers 

have a large lateral root system that extends well beyond the 

crown (Jameson 1967). The influence of individual trees on 

soil chemical properties has been demonstrated by many 

studies (Follet 1969; Garcia-Moya and Mckell 1970; 

Tiedemann and Klemmedson 1973; Zinke 1962). 

Arnold and others (1964) found conclusive reductions in 

the basal cover of grasses and forbs with the increase of 

canopy cover. Previous studies reveal a vast difference in 

herbaceous composition directly below the tree canopy and 

within the interspaces among trees (Armentrout and Pieper 

1988; Schott and Pieper 1985). The objective of this study 

was to determine if tree density and tree canopy cover 

influenced the composition and presence of understory species. The question then arises, if tree density is decreased 

through management will the understory become more 

diverse and percent ground cover increase? Also, at what 

tree density can one expect to meet management objectives 

for forage availability? Understanding this relationship 

with tree density and understory herbaceous composition 

will aid in management of pinyon-juniper woodlands. 

Study Site ________ _ 

The Pigeon Hollow study area is located in Sanpete 

County, Utah, approximately 8 km (5 miles) north of 

Ephraim (S 12, T 16, R 3). The elevation of the area ranges 

from 1,700 m (5,575 ft) to 1,900 m (6,235 ft). The average 

yearly precipitation is 321 mm, (12.6 inches) falling mostly 

during October and December. The average temperature 

ranges from 7.2 to 8.8 °C (45 to 47°F). Soils at Pigeon Hollow 

are excessively drained, gently sloping to very steep gravelly sandy loams that are 25.4 to 50.8 cm (10 to 20 inches) 

deep over limestone. Soils formed in colluvium, local alluvium, and residuum are derived from limestone on hillsides 

and ridges. They are of the Amtoft Series, most commonly 

associated with Sanpete and Sigurd soils (USDA, SCS, 

USDI, and BLM 1981). The Pigeon hollow area is owned by 

the Utah Division of Wildlife Resources and is managed as 

a wintering ground for wildlife. Habitat is provided for 

mule deer (Odocoileus hemionus [RafinesqueD and Rocky 

Mountain elk (Ceruus elaphus nelsoni [Bailey]), allowing 

both shelter and forage during the winter. All study sites 

USDA Forest Service Proceedings RMRS-P-9. 1999 
are located on north aspects with slopes of 4 to 5 percent. 

This area has not been grazed by livestock for 15 years 

except for periodic grazing by sheep. 

The prevalent grass species are: bluebunch wheatgrass 

(Pseudoroegneria spicata [Pursh]), Sandberg bluegrass 

(Poa secunda [Pres!.]), cheatgrass (Bromus tectorum), Indian 

ricegrass (Achnatherum hymenoides [Roem & Schult]), 

Needle-and-threadgrass(Hesprostipa [Trin.Rupr.] Barkw.), 

and bottle brush squirreltail (Elymus elymoides [Raf.] 

Swezey). The shrub component includes: big sagebrush 

(Artemisia tridentata [Nutt.]), narrowleaf low rabbitbrush 

(Chrysothamnus viscidiflorus [Hook]), winterfat (Ceratoides 

lanata [Pursh]), shadscale (Atriplex confertifolia [Torr. & 

Frem.]), and broom snakeweed (Gutierrezia sarothrae 

[Pursh]). Major forbs are: Hoods phlox (Phlox hoodii 

[Richards]), burr buttercup (Ranunculus testiculatus 

[Crantz]), aster species, and various annual mustards. 

Utah juniper, Two leaf, and pinyon pine are the main tree 

components. 

Methods _________ _ 

Three north facing slopes were chosen for sampling. 

Pinyon-juniper tree density decreased from east to west on 

each slope relating to the advancing front of a pinyonjuniper population. To sample different tree densities, each 

slope was divided into three tree density categories: high, 

moderate, and low. The assigned title to the categories does 

not necessarily represent exact or fixed densities but are 

high, moderate, and low, relative to one another. A 40 m2 site 

was sampled within each tree density category on each 

slope. All pinyon and juniper trees were counted in each 40 

m2 site to establish tree density. In addition, five stratified 

random points were selected in each plot for sampling 

herbaceous plant composition and tree canopy cover. A 

modified quarter method was used at each of these five 

points. In each cardinal quarter the distance to the nearest 

tree was measured and the species of tree identified. The 

quarter method and tree number counts were used at each 

site to calculate and verify tree density. Trees were classed 

into seedling, juvenile, adult, or decadent. Two 0.25 m2 

nested frequency frames were placed along the line connecting the sampling point and the nearest tree. One quadrat 

frame was placed under the tree canopy and another was 

placed in the tree interspace. The understory sample frame 

was placed midway between the trunk and canopy edge of 

each tree sampled. The interspace quadrat frame was placed 

within the nearest interspace along a line connecting the 

sampling point and the nearest tree trunk. To qualify as an 

interspace there could be no tree canopy cover within 2 m of 

the quadrat frame. Nested frequency data and eight cover 

points were recorded for each sample. Data were collected 

from 20 frames under the tree canopy and 25 frames in the 

interspace at each site. Summed frequency values were used 

to compare understory and interspace species. Smith and 

others (1987) have shown summed frequency values to be 

useful in comparing vegetation differences. A soil penetrometer was used at each sampling point to determine soil 

depth. Data were subject to analysis of variance using the 

General Linear Model (Ott 1984). Significant differences at 

p < 0.05 among means were determined using StudentN ewman-Kuels multiple range test on all main effect means. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Results And Discussion ____ _ 

Previous studies have demonstrated that as tree density 

increases understory decreases (Arnold and others 1964; 

Barney and Frishnecht 1974). In this study three categories 

of tree density were sampled to determine understory and 

interspace herbaceous composition at varying pinyonjuniper densities. The high and moderate tree densities 

contained 885 trees per ha (357 trees per acre) and 714 trees 

per ha (289 trees per acre). The low tree density contained 

394 trees per ha (159 trees per acre). The low tree density 

was significantly different from the moderate and high tree 

densities but moderate and high tree densities did not vary 

significantly from each other. A wider range of densities 

would have been helpful to separate moderate and high 

values. For this report high tree density will be compared to 

low tree density to examine the relationship between the 

undercanopy and interspace herbaceous composition. 

Four species consistently appeared in the sampling. The 

species included bluebunch wheatgrass, Sandberg bluegrass, cheatgrass and bur buttercup. These species are 

associated with pinyon juniper communities and serve as 

indicators of community health. Everett and Koniak (1981) 

found Sandberg bluegrass to be the most consistent perennial grass component in the understory of pinyon-juniper 

community, and cheatgrass was a common annual grass 

component. Figures 1, 2, and 3 report significant differences 

among understory and interspace frequency values for these 

species. 

Fewer species were encountered in the interspaces than 

in the understory. A total of 18 species were encountered 

in the understory while only 12 species appeared in the 

- 140 .S! 

:9 

t/) 120 

t/) 

0 

c. 100 

0 

~ 

N 80 -~ 

(.) 

c 60 

Q) 

::J 

C'" 40 

CI) 

~ 

'to- 20 E 

::J 

en 0 Pssp Pose Rate Brte 

Species 

D Understory II Interspace 

* Significant difference at p < 0.05 

Figure 1-Sum frequency at high tree density for bluebunch 

wheatgrass (Pssp), Sandberg bluegrass (Pose), bur buttercup (Rate), and cheatgrass (Brte). 

73 
-Q) 200 

:c 

en 

en 

0 

Co 150 

0 

III::t 

C\I 

-

>. 100 

0 

c:: 

Q) 

:J 

0-

Q) 50 ~ 

.... 

E 

:J 

en 0 Pssp Pose Rate Brte 

Species 

D Understory II Interspace 

* Significant difference at p < 0.05 

Figure 2-Sum frequency at moderate tree density for 

blue bunch wheatgrass (Pssp), Sandberg bluegrass (Pose), 

bur buttercup (Rate), and cheatgrass (Srte). 

interspace. Fewer annual species were recorded in the 

interspace than in the understory. 

At all tree densities, cheatgrass sum frequency values 

were significantly greater in the understory compared to the 

interspaces. At low tree density cheatgrass did not appear in 

the interspace but was limited entirely to the juniper understory. These findings are similar to reports of Everett and 

Koniaks (1981). Where cheatgrass is present it is closely 

associated with juniper canopy understory. 

Sandberg bluegrass had significantly higher sum frequency values in the understory of the low tree density than 

in the interspace (fig. 3). At the high tree density there was 

no difference between understory frequency and interspace 

frequency. The interspace was small enough and influenced 

by the tree density that herbaceous composition did not 

vary under the canopy or in the interspace. Sum frequency 

values were less for higher tree density indicating that as 

tree density increases Sandberg bluegrass decreases. There 

was less bur buttercup in the understory and interspace of 

the low tree density than the high tree density although not 

significantly less. 

Mean height of each juniper in the highest tree density 

area was 2.5 m. In the lowest tree density areas mean height 

was 3.01 m. Trees in the lowest tree density were 17 percent 

taller than those in the highest tree density areas. A decrease in average tree height may indicate competition for 

available resources among trees in the high density. Correlating with a decrease of tree height with increased tree 

density was a decrease in mean canopy cover by each 

individual tree as density increased. The mean canopy 

cover for the high density was 3.6 m2 as compared to 6.4 m2 

for the low density. Canopy cover was 47 percent less per 

individual tree in the high tree density compared to the low 

74 

- 200 ~ 

..c 

en 

en 

0 150 Co 

0 

III::t 

C\I 

->. 100 

0 

c:: 

Q) 

:J 

0-

Q) 50 ~ 

.... 

E 

:J 

en 0 Pssp Pose Rate Brte 

Species 

EJJJ Understory II Interspace 

* Significant difference at p < 0.05 

Figure 3-Sum frequency at low tree density for bluebunch 

wheatgrass (Pssp), Sandberg bluegrass (Pose), bur buttercup (Rate), and cheatgrass (Srte). 

tree density. The tree density significantly effected the tree 

size. The greater the tree density the smaller canopy cover 

of each tree. 

The data support the relationship of pinyon-juniper density to understory. In this sampling, as tree density increased understory and interspace herbaceous composition 

became less desirable and canopy cover declined. Considering this relationship very dense stands of pinyon-juniper 

woodlands are likely candidates for tree removal if management objectives warrant such an action. Low density 

pinyon-juniper woodlands can be more diverse and productive than very dense forest. 

References __________________ __ 

Armentrout, Susan M.; Pieper, R. D. 1988. Plant distribution 

surrounding Rocky Mountain pinyon pine and one-seed juniper 

in south-central New Mexico. Journal of Range Management. 

41(2): 139-143. 

Arnold, Joseph F. 1964. Zonation of vegetation around a Juniper 

tree. Journal of Range Management. 17: 41-42. 

Arnold, J. F.; Jameson, D. A.; Reid, E. H. 1964. The pinyon-juniper 

type of Arizona: effects of grazing, fire, and tree control. Production Res. Rep. No. 84. Fort Collins, CO: U.S Department Of 

Agriculture, Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 

Cottam, W. P. 1961. Our renewable wild lands~a challenge. Salt 

Lake City, UT: University of Utah Press. 

Barney, M. A.; Frischnecht, N. S. 1974. Vegetation changes following fire in the pinyon-juniper type of west-central Utah. Journal 

of Range Management. 27(2): 91-96. 

Dye, K. L., II; Ueckert, D. N.; Whisenant, S. G. 1995. Redberry 

juniper-herbaceous understory interactions. Journal of Range 

Management. 48: 100-107. 

Everett, R. L.; Koniak, S. 1981. Understory vegetation in fully 

stocked pinyon-juniper stands. Great Basin Naturalist. 41: 

467-475. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Follet, R. H. 1969. Zn, Fe, Mn and Cu in Colorado soils. Fort Collins, 

CO: Colorado State University. Dissertation. 

Garcia-Moya, E.; McKell, C. M. 1970. Contribution of shrubs to the 

nitrogen economy ofa desert-wash plant community. Ecology. 51: 

81-88. 

Jameson, D. A. 1967. The relationship of tree overstory and herbaceous understory vegetation. Journal of Range Management. 

20: 247-249. 

Ott, Lyman. 1984. An introduction to statistical methods and data 

analysis. Boston; PWS Publishers. 773 p. 

Schott, M. R.; Pieper, R. D. 1985. Influence of canopy characteristics 

of one-seed juniper on understory grasses. Journal of Range 

Management. 38: 328-331. 

Smith, S. D.; Bunting, S. C.; Hironaka, M. 1987. Evaluation of 

the improvement in sensitivity of nested frequency plots to 

vegetational change by summation. Great Basin Naturalist. 47: 

299-307. 

Stevens, R; Walker, S. C. 1996 Juniper-pinyon population dynamics over 30 years following anchor chaining. In: Barrow, Jerry, R; 

McArthur, E. Durrant; Sosebee, Ronald, E.; Tausch, Robin, J.; 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Proceedings: Shrubland ecosystem dynamics in a changing 

environment; 1995 May 23-25; Las Cruces, NM. Gen. Tech. Rep. 

INT-338. Ogden, UT: U.S. Department of Agriculture, Forest 

Service, Intermountain Research Station: 125-128. 

Tiedemann, A. R; Klemmedson, J. O. 1973. Effect of mesquite on 

physical and chemical properties of the soil. Journal of Range 

Management. 26: 27-29. 

U.S. Department of Agriculture, Soil Conservation Service and 

U.S. Department of the Interior, Bureau of Land Management. 

1981. In cooperation with Utah Agricultural Experiment Station 

and Utah State Department of Wildlife Resources. Soil survey of 

Sanpete Valley area, Utah; Parts of Utah and Sanpete Counties. 

179 p. 

West, N. E.; Van Pelt, N. S. 1986 Successional patterns in pinyonjuniper woodlands. In: Everett R L.; Proceedings: pinyonjuniper conference; 1986 Jan. 13-16; Reno, NV. Gen. Tech. Rep. 

INT-215. Ogden, UT: U.S. Department of Agriculture, Forest 

Service, Intermountain Research Station: 43-52. 

Zinke, P. T. 1962. The pattern of influence of individual forest trees 

on soil properties. Ecology. 43: 130-133. 

75 
Effects of Succession on Species Richness 

of the Western Juniper Woodlandl 

Sagebrush Steppe Mosaic 

Stephen C. Bunting 

James L. Kingery 

Eva Strand 

Abstract-The development of mature juniper woodlands has 

often been associated with decreases in the herbaceous and shrub 

components of the community. This study focused on changes in 

species richness and diversity along a successional gradient at both 

the community and watershed scale in the Owyhee Mountains in 

southwestern Idaho. Community species richness was relatively 

constant across the sere. Community species diversity changed as 

species became less equitably distributed when juniper dominated 

the site in the later stages of succession. Landscape-scale species 

richness is predicted to be greatest when all successional stages are 

represented in the watershed. 

Western juniper (Juniperus occidentalis subsp. occidentalis) dominates approximately 17 million ha in the northwestern portion of the Great Basin and southern Columbia 

Basin (West 1988). During the Pre-Euro-American period 

western juniper is thought to have primarily occurred as 

dense stands on the more dissected topography or to have 

occurred as open savanna-like woodlands on canyon slopes 

and more regular topography (Burkhardt and Tisdale 1969, 

1976, Miller and Rose 1994, Miller and Wigand 1994). 

Western juniper has primarily encroached into many adjacent vegetation types but the expansion of dominance has 

been most dramatic on the deeper soils (Young and Evans 

1981, Eddleman 1987, Miller 'and Rose 1994, Miller and 

Wigand 1994, Miller and others 1995). These types include 

those dominated by mountain big sagebrush (Artemisia 

tridentata subsp. vaseyana) steppe, aspen woodlands and 

Idaho fescue (Festuca idahoensis)/ bluebunch wheatgrass 

(Agropyron spicatum) grassland. Encroachment has also 

occurred into low sagebrush (Artemisiaarbuscula) dominated vegetation but the rate has been much lower due to the 

less productive site conditions. 

The causes of encroachment have been attributed to 

effects of overgrazing on plant competition by domestic 

livestock, climatic change and reduction wildfire occurrence 

by active suppression and livestock grazing (Blackburn and 

Tueller 1970, Burkhardt and Tisdale 1976, Young and 

In: Monsen, Stephen R; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogd~n, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountam Research 

Station. 

Stephen C. Bunting is Professor and James L. Kingery is Assistant 

Professor, Department of Range Resources and Eva Strand is GIS Analyst, 

Landscape Dynamics Lab, College of Forestry, Wildlife and Range Sciences, 

University ofIdaho, Moscow, ID 83844-1135. 

76 

Evans 1981, Gruell 1986, Miller and Wigand 1994). Research has shown that change in plant competition is probably not a factor in western juniper encroachment since 

plant composition did not affect the rate of establishment 

(Burkhardt and Tisdale 1976, Eddleman 1987, Miller and 

Rose 1994). However, heavy utilization of rangelands by 

livestock in the 19th and early 20th centuries would have 

facilitatedjuniper establishment through secondary effects. 

The resulting low fine fuel loads due to high forage utilization would have decreased fire occurrence (Miller and others 

1995) and increased sagebrush seedling establishment 

(Ellison 1960, Tisdale 1969). Increased sagebrush density 

provides greater availability of safesites for juniper since 

the majority of seedlings are found under sagebrush or other 

shrub canopies (Burkhardt and Tisdale 1976, Eddleman 

1987, Miller and Rose 1994, Miller and others 1995). 

Fire history studies in westernjuniper have indicated that 

pristine fire-free intervals (FFI) varied from 25-30 years 

(Burkhardt and Tisdale 1969, 1976) but may have been 

shorter than 25 years in associated mountain big sagebrush 

steppe (Bunting and others 1987, Miller and others 1995). 

Young and Evans (1981) estimated, based on the growth 

rate of young western juniper seedlings, that a fire every 

50 years would control the encroachment process in northern California. The encroachment of juniper usually reduces 

the herbaceous production on the site (Tausch and Tueller 

1990) and thereby greatly reduces fire potential (Bunting 

and others 1987, Everett 1987). In dense stands of mature 

juniper fires may burn only under the most severe weather 

conditions. 

The effects of encroachment are well documented for 

many juniper woodlands and are remarkably similar across 

the different juniper species and vegetation types. In general, there is a reduction in the herbaceous and shrub 

biomass production (Everett and Koniak 1981, Tress and 

Klopatek 1987, Wilson and Schmidt 1990, Vaitkus and 

Eddleman 1991). Other ecological changes which have been 

attributed to juniper encroachment include: increased soil 

erosion (Carrara and Carroll 1979), increased water use 

(Miller and Schultz 1987, Angel and Miller 1994, Miller and 

Wigand 1994), altered nutrient cycles (Klopatek 1987, 

Doescher and others 1987, Tiedemann and Klemmedson 

1995), reduced seed reserves (Koniak and Everett 1982) and 

reduced fire potential (Bunting and others 1987, Everett 

1987). 

Often associated with this reduction of herbaceous and 

shrub species is a reduction in plant and animal species 

diversity (Blackburn and Tueller 1970, West and others 

1979, Balda and Masters 1980, Koniak and Everett 1982, 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Severson 1986, Miller and others 1995). The effects of 

encroachment of western juniper woodlands into adjacent 

sagebrush steppe results in a decrease of herbaceous and 

shrub biomass production (Vaitkus and Eddleman 1991, 

Miller and Wigand 1994, Miller and others 1995). A reduction of plant species richness and species diversity has been 

documented for western juniper and other Great Basin 

woodlands (Blackburn and Tueller 1970, West and others 

1979, Koniak and Everett 1982, Miller and others 1994). 

Studies indicate that breeding bird density and species 

richness increases as western juniper stands become more 

mature and structurally diverse (Maser and Gashwiler 

1978, Sedgwick and Ryder 1987). Sedgwick and Ryder 

(1987) found that while bird densities decreased with juniper control, small mammals increased in response to greater 

herbaceous production. It seems most probable that in the 

process of conversion between juniper woodland and sagebrush steppe, some species will be affected positively and 

others negatively (Belsky 1996). The primary focus of this 

study is the landscape-scale influence of encroachment on 

vascular plant species diversity and richness. 

Methods _________ _ 

Two watersheds, Red Canyon Creek and Smith Creek, 

were selected for analysis (fig. 1). They are tributaries of the 

South Fork of the Owyhee River in southwestern Idaho and 

contain a variety of successional stages. The areas of Red 

Canyon Creek and Smith Creek watersheds are 63.7 and 

140.2 km2, respectively. Elevation varies from 1,500 to 

2,000 m. Domestic livestock have grazed the watersheds for 

over 100 years and currently cattle grazing occurs under a 

rest-rotation system. Less than 10 percent of each watershed has been treated with prescribed fire during the past 

20 years. 

Forty macroplots of approximately 0.25 ha within the 

western juniper-mountain big sagebrush mosaic were selected for sampling. These occurred over the successional 

gradient from herbaceous dominated (recently burned) to 

those dominated by stands of old juniper (greater than 500 

years in age). Sampling was limited to sites which currently 

or potentially may support sagebrush steppe vegetation in 

the successional sequence. This restriction was based on soil 

type and the presence of sagebrush plants or dead material. 

Macroplot vegetation was classified into one of9 structural 

stages based on composition and structure which were 

developed by the Interior Columbia Basin Ecosystem 

Management Project (ICBEMP) (Quigley and others 1996) 

(table 1). Macroplots were sampled for composition based on 

canopy coverage. The line intercept method was used to 

estimate shrub and tree coverage (Canfield 1941, Hanley 

1978). A modification of Daubenmire's (1959) cover class 

method was used to estimate coverage of the herbaceous 

species. A total macroplot inventory was done to determine 

the total number of species present on the site at the time of 

sampling. Species not included in the microplot or line 

intercept data were ranked from 0 to 5 based on foliar 

coverage and distribution. Sampling occurred near peak 

biomass production for the sites (late June-early July). 

Species richness was determined from a single inventory 

and was based on those species which occurred in the 

USDA Forest Service Proceedings RMRS-P-9. 1999 

II Western Juniper Woodland 

II Mountain Mahogany Woodland 

II Sagebrush Steppe 

2 4 6 miles 

o 2 4 6km 

Figure 1-Potential vegetation of Red Canyon Creek 

(lower) and Smith Creek (upper) watersheds which are 

tributaries of the South Fork of the Owyhee River in 

southwestern Idaho. Without disturbance, most of the 

upper portions of the watersheds will become dominated 

by western juniper vegetation. (Source: ICBEMP data) 

microplots and on the total macroplot search. The ShannonWeiner (Magurran 1988) and Simpson's diversity indices 

(Simpson 1949, Magurran 1988) were used to quantify 

differences in species diversity. 

Results __________ _ 

Consistent with previous research (Vaitkus and Eddleman 

1991, Miller and Wigand 1994, Miller and others 1995) 

development of western juniper woodland vegetation resulted in the reduction of shrub and herbaceous plant 

coverage (fig. 2). A reduction of plant species richness has 

been documented for sites dominated by western juniper 

and for other Great Basin juniper woodlands (Blackburn 

and Tueller 1970, West and others 1979, Koniak and Everett 

1982, Miller and others 1995), however, this did not occur in 

the watersheds studied in the Owyhee Mountains in Idaho. 

While there is a major change in plant community species 

composition with increasedjuniper dominance, species richness on a macroplot basis did not change across the successional gradient (fig. 3). This was true for species richness 

based on species sampled with microplots and for species 

77 
78 

Table 1-Description of structural stages used to classify vegetation within the mountain big sagebrush steppewestern juniper woodland mosaic of the Owyhee Mountains, Idaho. Structural stages used are 

modifications of those developed by ICBEMP. 

Structural stage 

Herbland 

Open shrubland 

Moderate cover shrubland 

Stand initiation woodland 

Stem exclusion woodland 

Understory re-initiation woodland 

Young multi-story woodland 

Old multi-story woodland 

Old single strata woodland 

Description 

Herbaceous cover <67 percent, shrub cover <5 percent 

Low and medium shrub cover <10 percent, tree cover <5 percent 

Low and medium shrub cover 10-67 percent, tree cover <5 percent 

Tree cover (all size classes) <5 percent, seedling-sapling cover >5 percent 

Large tree cover < 5 percent, small and medium tree cover >5 percent, 

seedling-sapling cover <5 percent 

Large tree cover <5 percent, seedling-sapling cover >5 percent 

Large tree cover 0-5 percent, small and medium tree cover 5-14 percent, 

seedling-sapling cover 5-14 percent 

Large tree cover 5-14 percent, other size classes 5-14 percent 

Large tree cover >5 percent, other size classes <5 percent 

60~------------------------------------------------------~ 

1 0 4---f'W;,['+---

o 

Herbland Open 

shrubland 

Moderate 

cover 

shrubland 

Stand 

initiation 

woodland 

Stem 

exclusion 

woodland 

Understory 

re-initiation 

woodland 

Young 

multi-story 

woodland 

Shrub steppe and woodland structural stage 

Old mUltistory 

woodland 

Figure 2-Data indicates that a reduction in the coverage of shrub and herbaceous species is associated with 

the development of western juniper woodlands. This is consistent with results from other juniper woodland 

studies from throughout the Great Basin and Southwest. 

Old single 

strata 

woodland 

USDA Forest Service Proceedings RMRS-P-9. 1999 
t/) 

Cl) 

'(3 

!. 

t/) 

'to0 

... 

Cl) 

.c 

E 

:J 

Z 

35.---------------------------------------------------~ 

30 

25 

20 

15 

10 

5 

o 

Herbland Open 

shrubland 

Moderate 

cover 

shrubland 

Stand 

Initiation 

woodland 

Stem 

exclusion 

woodland 

Understory Young 

re-initiation multi-story 

woodland woodland 

Shrub steppe and woodland structural stage 

Old multistory 

woodland 

Old single 

strata 

woodland 

Figure 3-Species richness did not change as a result of the development of juniper woodland 

development. Species richness 1 is based on those species encountered when sampling the stand. 

Species richness 2 is based on those species resulting from a one-time macroplot inventory. 

Table 2-Forb species associated with early to mid and late seral 

conditions within the mountain big sagebrush steppewestern juniper woodland mosaic in the Owyhee Mountains, Idaho. 

richness based on a complete macroplot inventory. Average 

species richness varied between 27-34 species for structural 

stages sampled across the successional gradient. The lowest 

average species richness occurred when young juniper began to dominate the site. At this stage many species found 

within sagebrush steppe were absent but those species 

associated with mature juniper woodlands had not become 

established. 

Species associated primarily 

with grassland and sagebrush 

steppe communities: 

Species associated primarily 

with old mature juniper 

woodland communities: 

Results indicated that many perennial herbaceous species are associated primarily with the early to mid seral 

communities and not found in the late seral communities 

(table 2). However, fewer instances of the reverse were 

evident. While late seral community species richness was as 

high as that of early and mid seral communities, the composition was comprised primarily of species that were also 

associated with other successional stages. In addition, due to 

the low perennial herbaceous plant cover, mature juniper 

communities contained high numbers of annual plants in 

the juniper interspaces. These included: cheatgrass (Bromus tectorum), Douglas knotweed (Polygonum douglasii), 

bl ue-eyed Mary (Collinsia parvi/lora), narrow -leafed collomia 

(Collomia linearis), Fremont's goosefoot (Chenopodium 

fremontii) and cryptantha (Cryptantha spp.). These annual 

species were also common in the early successional postburn communities. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Astragalus lentiginosus 

Calochortus nuttallii 

Castilleja applegatei 

Castilleja viscidula 

Eriogonum caespitosum 

Eriogonum heracleoides 

Eriogonum ovalifolium 

Eriogonum sphaerocephalum 

Eriogonun umbellatum 

Geranium viscosissimum 

Geum triflorum 

Fritillaria pudica 

Unum perenne var. lewisii 

Unum micranthum 

Mertensia longiflora 

Paeonia brownii 

Penstemon perpulcher 

Penstemon procerus 

Agastache urticifolia 

Aster chilensis 

Habenaria unalascensis 

Hackelia cusickii 

79 
Structural stages were grouped into 4 physiognomic types, 

grassland, sagebrush steppe, young juniper woodland and 

mature juniper woodland. Total species richness, those 

species found in at least 1 macroplot, for all physiognomic 

types was also similar across the successional gradient. 

Combined species richness for grassland, sagebrush steppe, 

young juniper woodland and mature juniper woodland 

macroplots was 65,65,60 and 70 species, respectively. These 

data indicate that highest landscape species richness (133 

species) of the watersheds would occur when all structural 

stages were present on the landscape. 

Since species richness did not change across the successional gradient, the changes in species diversity resulted 

primarily from differences in relative species abundance 

within the community. As mature juniper woodland develops, greater amounts of the community's total plant coverage and biomass is concentrated into fewer species. The 

number of species represented by only a few individuals in 

the macroplot tended to increase and species abundance 

becomes less equitable. This resulted in an increase in 

Simpson's Index and a decrease in the Shannon-Weiner 

Index as mature juniper woodland developed (fig. 4). 

Cl) 

::J 

ca 

> 

>< 0> 

" .5 

~ 'Ci) 

tO> 

> 

C 

2.5 

2 

1.5 

1 

0.5 

o 

Herbland Open 

shrubland 

Moderate 

cover 

shrubland 

Stand 

initiation 

woodland 

Conclusions _________ _ 

Although major changes in species composition and total 

plant coverage occurred, community species richness remained relatively constant across the successional gradient 

within the western juniper woodland-mountain big sagebrush steppe mosaic in southwestern Idaho. Changes in 

species diversity resulted as species became less equitably 

distributed within the communities as succession occurred. 

Maximum landscape species richness and specIes diversity 

occurs when all structural stages are represented within the 

watershed emphasizing the need to include disturbance 

such a fire as a process in landscape dynamics. 

Acknowledgments 

This research has been supported by the University of 

Idaho Forest, Wildlife and Range Experiment Station, Harold 

and Ruth Heady Professorship of Rangeland Ecology, and 

University of Idaho Landscape Dynamics Lab. We are also 

grateful for the assistance given by personnel ofthe Bureau 

of Land Management, Owyhee Resource Area. 

Ii Simpson's 

• Shannon-Weiner 

Stem Understory Young 

exclusion re-initiation multi-story 

woodland woodland woodland 

Old multistory 

woodland 

Old single 

strata 

woodland 

Shrub steppe and woodland structural stage 

80 

Figure 4-Changes in the Shannon-Weiner and Simpson's species diversity indices associated with western 

juniper woodland development in southwestern Idaho. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
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81 
Pinyon-Juniper Woodland Classification 

and Description in Research Natural Areas 

of Southeastern Idaho 

Steven K. Rust 

Abstract-Pinyon-juniper and juniper woodland vegetation occurs at the northern extent of its range in Idaho. In a nationwide 

study Idaho-endemic woodland communities are recognized as 

both the most rare and most poorly understood. To assist with their 

identification and description, and assess.ment of their conservation status, pinyon- and juniper-dominated woodland communities 

were sampled in Bureau of Land Management and National Forest 

System ecological reference areas. Pinyon-juniper vegetation observed at 12 Research Natural Areas and associated sites within 

southeastern Idaho is classified on the basis of perceived natural 

potential. Four series are recognized: singleleafpinyon (Pinus monophylla), Rocky Mountainjuniper (Juniperus scopulorum), Utahjuniper (Juniperus osteosperma), and curlleaf mountain-mahogany 

(Cercocal'pus ledifolius) on the basis of potential for dominance and 

relative tolerance of environmental stress. Twenty-three plant 

associations are identified. Community composition, distribution, 

and environmental relations are summarized. This information on 

stand composition and structure provides a baseline for conservation planning and ecosystem management. 

Pinyon-juniper and juniper woodland vegetation occurs 

at the northern extent of its range in Idaho (Cronquist and 

others 1972). Principle descriptive work on plant communities 

dominated by Utah juniper (Juniperus osteosperma), Rocky 

Mountain juniper (Juniperus scopulorum), and singleleaf 

pinyon (Pinus monophylla) has occurred in the southern 

Rocky Mountains and Great Basin (for example, Blackburn 

and others 1969, Baker 1984, and others). (To ease discussion, all vegetation in which singleleafpinyon, Utah juniper, 

and/or Rocky Mountain juniper are constituent species 

will be referred to in this paper as 'pinyon-juniper woodland.') Assessment of the conservation status, and development of effective habitat conservation strategies for pinyon-juniper woodland communities in Idaho is constrained 

by a lack of basic ecological descriptive work. For example, 

in a nationwieD study (Grossman and others 1994), seven 

pinyon-juniper woodland communities are recognized as 

occurring exclusively in Idaho; all are ranked most rare. 

These Idaho-endemic pinyon-juniper woodland communities are also all considered most poorly understood. 

In: Monsen, Stephen B.; Stevens, Richard, camps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Steven K. Rust is Ecologist, Conservation Data Center, Idaho Department 

of Fish and Game, 600 South Walnut, P.O. Box 25, Boise, ID 83707. 

82 

Research Natural Areas are established to provide a 

baseline reference against which the effects of intensive 

management may be assessed and evaluated. As well, an 

important objective of plant community conservation is to 

provide a coarse-filter by which the populations and habitats 

of multiple common and rare species may be captured. To 

effectively attain these goals and objectives information is 

needed on plant community composition, structure, and 

function. 

The objectives of this project are: (1) to assist with the 

identification and description of reference stand conditions 

in pinyon-juniper woodland communities on Bureau of 

Land Management and National Forest System lands in 

the Snake River Basalts, Northwest Basin and Range, and 

Overthrust Mountains ecological regions of Idaho (McNab 

and Avers 1994) and (2) to assist in the determination of 

their conservation status. The purpose of this paper is to 

present an initial classification of the pinyon-juniper vegetation observed in Research Natural Areas and other 

selected sites in southeastern Idaho and to summarize 

composition, distribution, and environmental relations. 

Methods -------------------------------------

Pinyon-juniper woodlands were sampled at proposed and 

designated natural areas and other selected sites within the 

southern portion of the range of pinyon-juniper woodland 

vegetation in Idaho. To the extent possible, stands present 

within each sampling site were delineated based on stand 

environmental features (topography and elevation) and 

apparent structure and composition (using aerial photography interpretation). Field sampling efforts were stratified 

within these reference stands. Ecology plots were selected to 

capture the range of conditions in stand structure and 

composition. Plots were placed within vegetation patches 

that are homogeneous in structure and composition. 

Basic environmental parameters (slope aspect, gradient 

and horizon; elevation; micro and macro topography; for 

example), plant cover, and the density and size distribution 

oflive and standing dead trees were determined on a standard (fixed) one-tenth acre circular ecology plot (Bourgeron 

and others 1991; USDA Forest Service 1992). Plant cover 

data were taken by ocular estimate for all vascular plant 

species. Ocular estimates of the cover of tree species were 

differentiated by strata (height/diameter class). Tree 

canopy height was determined for each height/diameter 

class. Live and standing dead tree stems present within the 

fixed area plot were tallied by species and size class (using 

the diameter at root crown). Soils and geology were documented from maps and, where necessary, verified and qualitatively described in the field. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Multivariate classification and ordination analytical 

techniques were employed in the description of plant communities and assessment of environmental factors. 

TWINS PAN (Hill 1979b) and DECORANA (Hill 1979a) 

were used interactively to derive an initial classification of 

the plot data through progressive decomposition of the 

data to smaller, more similar groups. This classification was 

refined and environmental correlations were developed 

through the use ofCANOCO (ter Braak 1991), again using 

an approach of progressive decomposition. Data analysis 

was aided through the use ofECOAID (Smith 1993), a data 

manipulation and summary package. 

Results and Plant Community 

Characterization 

Pinyon-juniper woodland sites visited during the 1995 

and 1996 field seasons are listed in table 1. All formally 

designated natural areas on Snake River Resource Area 

and National Forest System lands known to encompass 

stands of pinyon -j uni per woodland were visited. Previously 

unrecognized pinyon-juniper woodlands were visited at 

Burton Canyon RNA. Sampling also occurred at four sites 

which occur throughout the range of singleleaf pinyon in 

Idaho, including City of Rocks RNA, Jim Sage Canyon RNA, 

Pine Knob, and Slide Canyon. Information regarding the 

biological and physical characteristics and protection and 

stewardship status of these sites is available from Idaho 

Conservation Data Center upon request. 

Pinyon-juniper vegetation observed in this study is classified on the basis of perceived natural potential. Four series 

are recognized: singleleafpinyon, Rocky Mountain juniper, 

Utahjuniper, and curlleafmountain-mahogany on the basis 

of potential for dominance and relative tolerance of environmental stress. The 23 plant associations identified 

within these series are listed in table 2. 

The singleleaf pinyon, Rocky Mountain juniper, Utah 

juniper and curlleafmountain:-mahogany series occur on an 

apparent environmental gradient of moisture availability 

and temperature. These environmental gradients are reflected in differences in elevation, substrate characteristics 

and parent materials, and slope aspect and exposure. 

In the vegetation descriptions that follow, Federal Geographic Data Committee (1996) national vegetation classification terminology is used to the extent possible. The Federal Geographic Data Committee (1996), however, is not 

repeatedly cited. Tree stem size classes referred to in the 

discussion are defined as follows: seedling, trees <4.5 ft tall; 

sapling, trees <4.9 inch diameter at root crown height (and 

>4.5 ft tall); pole, 5.0-8.9; medium-sized tree, 9.0-20.9; largesized tree, 21.0-32.9; and very large-sized tree, ~33.0 inch 

diameter at root crown height. Plant species abundance 

classes referred to in the text are defined as follows: present, 

>0 percent cover; common, ~1 percent cover; well represented, ~5 percent cover; and abundant, ~25 percent cover. 

Curlleaf Mountain-mahogany 

Series -------------------------------------- Curlleafmountain-mahogany occurs over a wide range 

of environmental conditions within the study area. Curlleaf 

mountain-mahogany-dominated vegetation was sampled 

only in stands adjacent to singleleaf pinyon-, Rocky Mountain juniper-, or Utah juniper-dominated stands. Thus 

the range of variation in curlleaf mountain-mahoganydominated vegetation discussed here is limited. Curlleaf 

mountain-mahogany is apparently seral to singleleaf pinyon and Rocky Mountain juniper. The successional and 

environmental relationships of curlleafmountain-mahogany 

and Utah juniper are less clear. Utah juniper was not 

observed reproducing successfully in the understory of 

curlleafmountain-mahogany as were singleleafpinyon and 

Rocky Mountain juniper. 

Data for a limited number of stands which represent lateseral curlleaf mountain -mahogany woodland were collected 

at Burton Canyon. These samples are classified as curlleaf 

mountain -mahogany/mountain snowberrylbl uebunch wheatgrass (Cercocarpus ledifolius / Symphoricarpos oreophilus / 

Agropyron spicatum). This plant association is compositionally and environmentally similar to plant associations described here as singleleaf pinyon-curlleaf mountainmahoganylbush oceanspraylbasin wildrye (Pinus monophyllaCercocarpus ledifolius / Holodiscusdumosus / Elymus cinereus), 

Rocky Mountain juniper-curlleaf mountain-mahogany/ 

mountain snowberrylbluebunch wheatgrass (Juniperus 

Table 1--Research Natural Areas and associated sites representing pinyon-juniper 

vegetation in southeast Idaho. 

Site Quadrangle Township Range Sec. 

Big Juniper Kipuka Rattlesnake Butte 6S 27E 36 

Burton Canyon Grace 9S 41E 33 

City of Rocks Almo 15S 24E 19 

Gibson Jack Pocatello South 7S 34E 23 

Goose Creek Mesa Ibex Peak 16S 21E 20 

Jim Sage Canyon Jim Sage Canyon 15S 25E 15 

Elba 15S 25E 15 

Pine Knob View 12S 24E 3 

Sand Kipuka Lake Walcott East 8S 27E 10 

Slide Canyon Cache Peak 14S 23E 1 

Trapper Creek Severe Spring 15S 21E 6 

Two Mile Canyon Malad City East 14S 36E 25 

W Fork Mink Creek Clifton Creek 8S 34E 2 

USDA Forest Service Proceedings RMRS-P-9. 1999 83 
Table 2-Classification of pinyon-juniper woodland communities in Research Natural Areas of southeastern Idaho. Plant associations are listed 

by series with the abbreviated name, scientific name, and common name. 

Abbreviation 

CELE/SYOR/BASAIAGSP 

JUOS-CELE/SYOR/AGSP 

JUOS/SYOR/ AGSP 

JUOS/ARTRW/STCO 

JUOS/ARTRV/FEID 

JUOS/ARTRV/AGSP 

JUOS/ARTRV/ORHY 

JUOS/ARAR/FEID 

JUOS/ARAR/AGSP 

JUOS/ARNO/AGSP 

JUOS/ ARNO/POSE 

JUSC-CELE/SYOR/AGSP 

JUSC/ARTRV-SYOR/ELCI 

JUSC/ARTRW-CHMI 

JUSC/ARTRW 

JUSC/HODU 

JUSC/HANA 

PI MO-CELE/HODU/ELCI 

Scientific Name 

Curlleaf Mountain-mahogany Series 

Cercocarpus ledifoliuslBalsamorhiza sagitta tal 

Agropyron spicatum 

Utah Juniper Series 

Juniperus osteosperma-Cercocarpus ledifoliusl 

Symphoricarpos oreophiluslAgropyron spicatum 

Juniperus osteospermaiSymphoricarpos 

oreophHuslAgropyron spicatum 

Juniperus osteospermaiArtemisia tridentata 

wyomingensislStipa comata 

Juniperus osteospermaiArtemisia tridentata 

vaseyanaiFestuca idahoensis 

Juniperus osteospermaiArtemisia tridentata 

vaseyanal Agropyron spicatum 

Juniperus osteospermaiArtemisia tridentata 

vaseyanalOryzopsis hymenoides 

Juniperus osteospermaiArtemisia arbuscula 

arbusculaiFestuca idahoensis 

Juniperus osteospermaiArtemisia arbuscula 

arbusculal Agropyron spicatum 

Juniperus osteospermaiArtemisia arbuscula 

novaiAgropyron spicatum 

Juniperus osteospermaiArtemisia arbuscula 

novalPoa secunda 

Rocky Mountain Juniper Series 

Juniperus scopulorum-Cercocarpus ledifoliusl 

Symphoricarpos oreophiluslAgropyron spicatum 

Juniperus scopulorumlArtemisia tridentata vaseyanaSymphoricarpos oreophiluslAgropyron spicatum 

Juniperus scopulorumlArtemisia tridentata 

wyomingensis-Chamaebatiaria millifolium 

Juniperus scopulorumlArtemisia tridentata 

wyomingensis 

Juniperus scopulorumlHolodiscus dumosus 

Juniperus scopulorumlHaplopappus nanus 

Singleleaf Pinyon Series 

Pinus monophylla-Cercocarpus ledifoliusl 

Holodiscus dumosuslElymus cinereus 

PIMO-CELE/SYOR-BERE/AGSP Pinus monophylla-Cercocarpus ledifolius/ 

Symphoricarpos oreophilus-Berberis repensl 

Agropyron spicatum 

PIMO-CELE/POSE 

PIMO-JUOS/ ARTRV/AGSP 

PIMO-JUOS/AGSP 

PI MO-JUOS/ ARNO/POSE 

84 

Pinus monophylla-Cercocarpus ledifoliuslPoa secunda 

Pinus monophylla-Juniperus osteospermaiArtemisia 

tridentata vaseyanaiAgropyron spicatum 

Pinus monophylla-Juniperus osteospermal 

Agropyron spicatum 

Pinus monophylla-Juniperus osteospermaiArtemisia 

arbuscula novaiPoa secunda 

Common Name 

curlleaf mountain-mahogany/arrowleaf 

balsamrootlbluebunch wheatgrass 

Utah juniper-curlleaf mountain-mahogany 

mountain snowberry/bluebunch wheatgrass 

Utah juniper/mountain snowberry/bluebunch 

wheatgrass 

Utah juniperlWyoming big sagebrush/needleand-thread 

Utah juniper/mountain big sagebrush/Idaho 

fescue 

Utah juniper/mountain big sagebrush/ 

bluebunch wheatgrass 

Utah juniper/mountain big sagebrush/indian 

ricegrass 

Utah juniper/low sagebrush Idaho fescue 

Utah juniper/low sagebrush bluebunch 

wheatgrass 

Utah juniper/black sagebrush bluebunch 

wheatgrass 

Utah juniper/black sagebrush/Sandberg 

bluegrass 

Rocky Mountain juniper-curlleaf mountainmahogany/mountain snowberry/bluebunch 

wheatgrass 

Rocky Mountain juniper/mountain big 

sagebrush-mountain snowberry/bluebunch 

wheatgrass 

Rocky Mountain juniperlWyoming big 

sagebrush/desertsweet 

Rocky Mountain juniperlWyoming big 

sagebrush 

Rocky Mountain juniper/bush oceanspray 

Rocky Mountain juniper/dwarf goldenweed 

singleleaf pinyon-curlleaf mountain-mahogany/ 

bush oceanspray/Great Basin wild rye 

singleleaf pinyon-curlleaf 

mountain-mahogany/mountain snowberry 

Oregongrape/bluebunch wheatgrass 

singleleaf pinyon-curlleaf mountain-mahogany 

Sandberg bluegrass 

singleleaf pinyon-Utah juniper/mountain big 

sagebrush/bluebunch wheatgrass 

singleleaf pinyon-Utah juniper/bluebunch 

wheatgrass 

singleleaf pinyon-Utah juniper/black 

sagebrush/Sandberg bluegrass 

USDA Forest Service Proceedings RMRS-P-9. 1999 
scopulorum-Cercocarpus ledifolius / Symphoricarpos oreophilus / Agropyron spicatum), and Utah juniper-curlleaf 

moun tain -mahogany/mountain snow berry/bl uebunch 

wheatgrass (Juniperus osteosperma-Cercocarpus ledifolius / 

Symphoricarpos oreophilus / Agropyron spicatum). Late-seral curlleaf mountain-mahogany-dominated woodland was 

also observed in ridge top positions on north-facing aspects 

at City of Rocks. Additional work is needed in these curlleaf 

mountain-mahogany-dominated plant communities. 

Rocky Mountain Juniper 

Series 

Upland Rocky Mountain juniper-dominated woodlands 

occur on the Wapi Flow, within the Snake River Plain; south, 

on lower-slope positions, in the Goose Creek drainage; and 

east, with increasing extent, on lower- and upper-slope 

positions, in the Bannock, Portneuf, and Bear River ranges 

and on basalt flows ofthe PortneufRiver valley of southeastern Idaho. 

Rocky Mountain juniper-dominated woodlands were 

sampled at relatively few sites. The plant associations identified here typically have a relatively narrow distribution 

among the sites sampled. These data may not represent the 

ecological variability of Rocky Mountain juniper-dominated 

woodlands within the study area. Rocky Mountain juniper 

plant communities observed range from dense woodlands of 

the northern Bear River Range which posses high understory cover of mountain shrub species and are characterized 

by the co-dominance of curlleafmountain-mahogany, to very 

open, sparsely vegetated woodlands ofthe Wapi Flow, on the 

southern end of the Great Rift system. 

Rocky Mountainjuni per-dominated woodlands occur with 

a bimodal elevational distribution. Stands were sampled at 

both the highest and the lowest elevations. Stands are often 

associated with bedrock outcrops. Bedrock may serve an 

ameliorative function, by reducing evaporative soil moisture 

loss and dampening soil temperature extremes, in an otherwise hot, dry upland rooting environment. Rock structures 

may also serve to funnel and catch precipitation run-off. 

Rocky Mountain Juniper-Curlleaf 

Mountain-mahogany/Mountain Snowberry/ 

Bluebunch Wheatgrass Plant Association 

Distribution-Rocky Mountain juniper-curlleaf mountain -mahogany/mountain snowberrylbl uebunch w heatgrass 

was sampled in stands located at one site, Burton Canyon, 

on the northern end of the Bear River Range. Based on 

cursory reconnaissance, the association is expected to be 

extensive in the vicinity and may occur south in the Wasatch 

Range in Utah and east toward the Salt River Range in 

Wyoming. 

Vegetation-This vegetation is an open (extremely 

xeromorphic) evergreen woodland (Federal Geographic Data 

Committee 1996). Rocky Mountain juniper and curlleaf 

mountain-mahogany are co-dominant; the later species usually being the more abundant. Mountain snow berry is present 

and may be abundant. Oregongrape (Berberis repens) is 

often well represented. Mountain maple (Acer glabrum) 

USDA Forest Service Proceedings RMRS-P-9. 1999 

and western serviceberry (Amelanchier alnifolia) are common, but not consistently present. The herbaceous understory is diverse. Arrowleafbalsamroot (Balsamhoriza sagittata) and bluebunch wheatgrass (Agropyron spicatum) are 

well represented to abundant. 

Environment-This association was observed on mixed 

miogeosynclinal substrates. It is often associated with bedrock outcrops, but not consistently. It is located within the 

upper drainages oflow, mountainous terrain, on mid- and 

lower-slope positions with southwesterly aspects. The mean 

elevation (± standard deviation) of sample plots was 6,907 

(±234) ft. 

Other Studies-Similar Rocky Mountainj uniper-curlleaf 

mountain-mahogany-dominated vegetation is described for 

the eastern portion of the Beaverhead Mountains ecoregional 

section in Montana by Cooper and others (1995). Additional 

work is needed to draw conclusions about the similarities 

and differences in Rocky Mountain juniper-curlleaf mountain-mahogany-dominated vegetation within the region. 

Rocky Mountain Juniper/Mountain Big 

Sagebrush-Mountain Snowberry/Basin 

Wildrye Plant Association 

Distribution-Rocky Mountain juniper/mountain big 

sagebrush-mountain snowberrylbasin wildrye (Juniperus 

scopulorum / Artemisia tridentata vaseyana-Symphoricarpos oreophilus / Elymus cinereus) was sampled on four plots 

located at one site, West Fork Mink Creek RNA, within the 

Bannock Range. The association is expected to occur in 

similar habitats in the Bannock and Portneuf ranges and 

may also be present farther east. 

Vegetation-The vegetation is (microphyllous) evergreen 

shrubland. The average cover oftrees is <25 percent and less 

then the average sum of shrub, herb, and grass cover. Midseral occurrences were sampled; represented by the adventitious establishment of Rocky Mountain juniper within 

mountain big sagebrush (Artemisia tridentata vaseyana), 

western serviceberry and mountain snowberry co-dominated shrubland. Oregongrape is often well represented, but 

not consistently. A rich assemblage of mesic forbs are present, 

characterized by giant-hyssop (Agastache urticifolia) and 

Wyeth buckwheat (Eriogonum heracleoides). Basin wildrye 

(Elymus cinereus) is well represented to abundant. Douglasfir (Pseudotsuga menziesii) may eventually become established as a late-seral species in these stands (though this 

was not observed). The time period for succession to Douglasfir occupancy may be longer, however, then the interval 

between fire disturbance events which would eliminate 

Douglas-fir establishment. 

Environment-This association was sampled on mixed 

carbonate substrates. Rocky Mountain juniper/mountain 

big sagebrush-mountain snowberrylbasin wildrye occurs on 

the upper slopes of low, mountainous terrain, within concave draws in mid- and lower-slope micro-topographical 

positions, often at the toe of rock outcrop or talus formations. 

The mean elevation (± standard deviation) of sample plots 

was 6,359 (±161) ft. 

Other Studies-Similar vegetation is (or contained within 

associations) described by Cooper and others (1995), Hess 

and Alexander (1986), and Johnston (1987). This association 

85 
incorporates stands incorrectly identified by Grossman and 

others (1994) as Utahjuniperlbitter-brush-mountain snowberrylbluebunch wheatgrass (Juniperus osteosperma / 

Purshia tridentata-Symphoricarpos oreophilus / Agropyron 

spicatum). Additional work is needed to draw conclusions 

about the similarities and differences in this vegetation 

within the region. 

Rocky Mountain JuniperlWyoming Big 

Sagebrush-Fern-bush Plant Association 

Distribution-Rocky Mountain juniperlWyoming big 

sagebrush-fern-bush (Juniperus scopulorum/Artemisia 

tridentata wyomingensis-Chamaebatiaria millifolium) was 

only observed on the Wapi Flow. All of the data for this plant 

association were collected in the vicjnity of Sand Kipuka 

RNA, on the southern end of the Wapi Flow. The community 

was also observed in the vicinity of Big Juniper Kipuka, on 

the northern end of the Wapi Flow. Similar vegetation may 

occur on mafic volcanic flow substrates on the Snake River 

Plain and in the PortneufValley. 

Vegetation-The vegetation is characterized by an open 

woodland structure of (typically) large diameter, broad, 

limby Rocky Mountain juniper. Shrub understory is patchy 

and dense in association with multiple medium sized fissures to highly fractured basalt. Shrubs include fern-bush 

(Chamaebatiaria millifolium), Wyoming big sagebrush (Artemisia tridentata wyomingensis), bitterbrush (Purshia tridentata), and syringa (Philadelphus lewisii). Sandberg's 

bluegrass (Poa secunda) is common. Understory regeneration of Rocky Mountainjuniper is usually present in a range 

of age and size classes. 

Environment-Rocky Mountain juniperlWyoming big 

sagebrush-fern-bush occurs on mafic volcanic flow substrates. The sites are highly fractured, undulating basalt 

basins of collapsed lava tubes. The comm uni ty tends to occur 

on northeast and easterly aspects, adjacent to (downslope of) 

Rocky Mountainjuniperlbush oceanspray (Juniperus scopulorum/ Holodiscus dumosus) on lava and Rocky Mountain 

juniperlWyoming big sagebrush (Juniperus scopulorum / 

Artemisia tridentata wyomingensis) at the contact of lava 

and kipuka sand. The mean elevation (± standard deviation) 

of sample plots was 4,368 (±12) ft. 

Other Studies-Woodland stands on the Wapi Flow 

were previously described as Utahj uniper-dominated. Rocky 

Mountain juniperlWyoming big sagebrush-fern-bush is not 

described in other studies. 

Rocky Mountain Juniper/Bush 

Oceanspray Plant Association 

Distribution-Rocky Mountainjuniperlbush oceanspray 

was only observed on the Wapi Flow. The community was 

sampled at both the northern and southern end of the flow. 

Similar vegetation may occur on mafic volcanic flow substrates on the Snake River Plain. 

Vegetation-This is sparse (needle-leaved or microphyllous) evergreen dwarf-shrubland vegetation. Rocky Mountainjuniper density is low and the tree canopy is very open. 

86 

Many sites sampled on the northern Wapi Flow are earlyseral. This vegetation is developing in the vicinity of Pillar 

Butte, north of Big Juniper Kipuka, throughprimarysuccession. Stands in the south are characterized by low growing, 

wind trained Rocky Mountain juniper. Bush oceanspray 

(Holodiscus dumosus) is typically associated with few, large 

fissures on these sites. Dwarf goldenweed (Haplopappus 

nanus) is often well represented and occurs with hot-rock 

penstemon (Penstemon deustus) on multiple fine crevices. 

Moss and lichen are usually abundant. Sandberg's bluegrass is often growing in thick mosslleaf litter mats which 

occur in the understory of Rocky Mountain juniper. 

Environment-Rocky Mountainjuniperlbush oceanspray 

occurs on mafic volcanic flow substrates. The sites are of 

convex micro-topography, dry, and well drained. The plant 

association is usually located on south and southeast aspects 

on the crest of lava pressure ridges. Few large tension 

fissures are present with many to numerous small crevices. 

The mean elevation (± standard deviation) of sample plots 

was 4,858 (±316) ft. Rocky Mountain juniper/dwarf 

goldenweed (Juniperus scopulorum / Haplopappus nan us) 

and Rocky Mountain juniper-Wyoming big sagebrush-fernbush are adjacent, respectively, on sites with fewer large 

fissures and highly fractured basalt basins. 

Other Studies-Woodland stands on the Wapi Flow 

were previously described as Utahjuniper-dominated. Rocky 

Mountainjuniperlbush oceanspray is not described in other 

studies. 

Rocky Mountain Juniper/Dwarf 

Goldenweed Plant Association 

Distribution-Rocky Mountain juniper/dwarf goldenweed was only observed on the Wapi Flow. The community 

was sampled at both the northern and southern end of the 

flow. Similar vegetation may occur on mafic volcanic flow 

substrates on the Snake River Plain. 

Vegetation-This is (needle-leaved or microphyllous) 

evergreen dwarf-shrubland vegetation. The average cover of 

trees is less then the average sum of shrub, herb, and grass 

cover. Rocky Mountain juniper/dwarf goldenweed is structurally intermediate to Rocky Mountain juniperlbush 

oceanspray and Rocky Mountain juniper-Wyoming big 

sagebrush-fern-bush. Rocky Mountain juniper tree density 

is low and canopy cover is low. Dwarf goldenweed, prickly 

phlox (Leptodactylon pungens) and hot-rock penstemon are 

common, though typically not well represented. Mosses and 

lichens are usually abundant. As described for Rocky Mountain juniper/bush oceanspray, early-seral occurrences of 

this association are on the northern end of the Wapi Flow; 

late-seral occurrences, the southern. 

Environment-Rocky Mountain juniper/dwarf goldenweed occurs on mafic volcanic flow substrates. The sites are 

variable in configuration and slope position. This plant 

association typically occurs on basalt surfaces with multiple medium to fine fissures; rather than with large crevices 

or highly fractured basalt. These relatively flat, smooth 

bedrock substrates occur on both pressure ridgelines and 

within basins formed through the collapse oflava tubes. The 

mean elevation (± standard deviation) of sample plots was 

USDA Forest Service Proceedings RMRS-P-9. 1999 
4,663 (±335) ft. Rocky Mountain juniperibush oceanspray 

and Rocky Mountain juniper-Wyoming big sagebrushfern-bush are adjacent communities. 

Other Studies-Woodland stands on the Wapi Flow 

were previously described as Utahjuniper-dominated. Rocky 

Mountain juniper/dwarf goldenweed is not described in 

other studies. 

Rocky Mountain JuniperlWyoming Big 

Sagebrush Plant Association 

Distribution-Rocky Mountain juniperlWyoming big 

sagebrush was sampled within Sand Kipuka on two plots. 

The association is common on the Wapi Flow where winddeposited sand has the capability to support Rocky Mountain juniper. Similar vegetation likely occurs northeast of 

the Wapi Flow, within the Snake River Plain (The Nature 

Conservancy and others 1987). 

Vegetation-This is (microphyll us) evergreen shrub land 

vegetation. The average cover of trees is less then the 

average sum of shrub, herb, and grass cover. Mid-seral 

occurrences were sampled. These stands are represented by 

the adventitious establishment of Rocky Mountain juniper 

within, otherwise, Wyoming big sagebrush-dominated shrubland. Rocky Mountainjuniper density and tree canopy cover 

are low. Wyoming big sagebrush is well represented with 

green rabbitbrush (Chrysothamnus viscidifiorus). Pricklypear (Opuntia polyacantha) is common. Sand wildrye (Elymus fiavescens) is characteristically well represented. 

Environment-This plant association occurs on stabilized, windblown sand deposits within mafic volcanic flow 

formations on basin bottom and toe-slope positions immediately adjacent basalt bedrock. 

Other Studies-Woodland stands on the Wapi Flow 

were previously described as Utahjuniper-dominated. Rocky 

Mountain juniperlWyoming big sagebrush is not described 

in other studies. 

Singleleaf Pinyon Series 

Singleleafpinyon is known in Idaho from the Albion, Jim 

Sage, and Black Pine mountains. Stands were sampled at 

four sites within the extent of its range in Idaho. Singleleaf 

pinyon is co-dominant in this woodland vegetation with 

curlleafmountain-mahogany and Utah juniper. Plant communities range in character from open, savanna-like woodlands with an open grassy understory to dense stands with 

abundant, continuous shrub cover. Singleleafpinyon woodlands are located in upslope positions on the spur ridges of 

moderately high mountainous terrain. 

Singleleaf Pinyon-Curlleaf Mountainmahogany/Bush Oceanspray/Basin 

Wildrye Plant Association 

Distribution-Singleleaf pinyon -curlleafmountain-mahoganyibush oceansprayibasin wildrye was sampled at City 

of Rocks RNA, on the southern end of the Albion Range. The 

association is well represented at this location but has not 

been observed elsewhere in Idaho. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Vegetation-This plant association is (rounded crowned 

temperate or subpolar needle-leaved) evergreen forest. 

Singleleafpinyon and curlleafmountain-mahogany are codominant, the later usually being the most abundant. Rocky 

Mountain juniper is common, but rarely abundant. The 

understory is characterized by abundant cover of mountain 

shrub species (in order of importance): bush oceanspray, 

Oregongrape, and mountain snowberry. Mountain big sagebrush and squaw current (Ribes cereum) are often present, 

but not abundant. Few understory herbaceous species occur 

in these forest/woodlands. Basin wildrye is consistently 

present but only common. 

Environment-Singleleaf pinyon-curlleaf mountainmahoganyibush oceansprayibasin wildrye is only observed 

on granitic substrates within the Albion Mountains. The 

plant association occurs on lower ridge spurs of moderately high elevation mountainous terrain in upper-slope 

positions on relatively dry, steep, convex north- to east- to 

south-facing slopes. The soil surface is usually bouldery. The 

mean elevation (± standard deviation) of plots was 6,873 

(±249) ft. Stands sampled show moderate to high woody fuel 

accumulations. 

Other Studies-Singleleaf pinyon-curlleaf mountainmahogany-dominated vegetation is described by Heize and 

others (1962) from the Steptoe watershed in Nevada. The 

association described here incorporates stands identified by 

Caicco and Wellner (1983a) as singleleaf pinyon/Utah 

juniperibasin wildrye (Pinus monophylla/Juniperus osteosperma/ Elymus cinereus) and singleleafpinyonlUtahjuniper/chokecherry (Pinus monophylla / Juniperus osteosperma / 

Prunus virginiana). The more refined singleleaf pinyoncurlleafmountain -mahoganyibush oceansprayibasin wildrye 

plant association has not been described elsewhere. 

Singleleaf Pinyon-Curlleaf Mountainmahogany/Mountain SnowberryOregongrape/Bluebunch Wheatgrass 

Plant Association 

Distribution-Singleleaf pinyon-curlleaf mountainmahogany/mountain snowberry-Oregongrapeibluebunch 

wheatgrass (Pinus monophylla-Cercocarpus ledifolius / 

Symphoricarpos oreophilus-Berberis repens / Agropyron 

spicatum) was observed in the west-central and southern 

Albion Mountains. The association is expected to have at 

least a moderately extensive distribution within the range of 

singleleaf pinyon, but this has not been determined. 

Vegetation-This is (rounded-crowned temperate or subpolar needle-leaved) evergreen forest vegetation. Early- to 

mid-seral occurrences were sampled. In these conditions 

curlleafmountain-mahogany is dominant in the overstory. 

Singleleaf pinyon is often present in the overstory and is 

consistently present in the understory. The understory shrub 

structure is similar to that of singleleaf pinyon-curlleaf 

mountain-mahoganyibush oceansprayibasin wildrye. Mountain shrub species are consistently well represented to 

abundant, including: Oregongrape and mountain snowberry. Mountain big sagebrush and squaw current are often 

present, but usually with low cover. Bush oceanspray is 

usually absent. A good number of herbaceous species may 

be present. Grass species are well represented. Bluebunch 

wheatgrass and spike fescue (Leucopoa kingii) are common 

and relatively constant. 

87 
Environment-The plant association is observed on both 

carbonate and granitic substrates. Sites are located on lower 

ridge spurs of moderately high elevation mountainous terrain in mid- and upper-slope positions on relatively dry, 

steep, convex east- to south- to west-facing slopes. Fuels are 

characteristically fine herbaceous materials with some dead 

stemwood. Singleleaf pinyon -curlleaf mountain-mahogany/ 

mountain snowberry-Oregongrapelbluebunch wheatgrass 

is adj acent singleleaf pinyon -curlleaf mountain-mahogany/ 

bush oceanspraylbasin wildrye on more southwesterly aspects and is often upslope of singleleaf pinyon-curlleaf 

mountain-mahogany/Sandberg's bluegrass (Pinus monophylla-Cercocarpus ledifolius / Poa secunda). The mean elevation (± standard deviation) of samples was 7,090 (±298) ft. 

Other Studies-Singleleaf pinyon-curlleaf mountainmahogany-dominated vegetation is described by Heize and 

others (1962) from the Steptoe watershed in Nevada. The 

association described here incorporates stands identified by 

Caicco and Wellner (1983a) as singleleafpinyonlUtahjuniperlcurlleaf mountain-mahoganylbig mountain sagebrush! 

bluebunch wheatgrass (Pinus monophylla/Juniperus osteosperma / Cercocarpus ledifolius / Artemisia tridentata 

vaseyana / Agropyron spicatum). The singleleaf pinyoncurlleaf mountain-mahogany/mountain snowberryOregongrapelbluebunch wheatgrass plant association has 

not been described elsewhere. 

Singleleaf Pinyon-Curlleaf Mountainmahogany/Sandberg's Bluegrass Plant 

Association 

Distribution-Singleleaf pinyon -curlleaf mountain -mahogany/sandberg's bluegrass was observed on 18 plots located in the west-central and southern Albion Mountains, at 

Slide Canyon, and City of Rocks, respectively. The association is expected to have at least a moderately extensive 

distribution within the range of singleleaf pinyon, but this 

has not been determined. 

Vegetation-This vegetation is classified by current national standards as rounded-crowned temperate or subpolar 

needle-leaved evergreen woodland. In stands sampled, 

singleleaf pinyon and curlleaf mountain-mahogany are codominant in often nearly equal proportions. Mountain snowberry and mountain big sagebrush are often present and 

may be well represented. Sandberg's bluegrass is consistently well represented. Cheatgrass (Bromus tectorum) is 

usually abundant. 

Environment-The plant association is observed on both 

carbonate and granitic substrates. Sites are located on lower 

ridge spurs of moderately high elevation mountainous terrain in mid- and upper-slope positions on relatively dry, 

moderately sloped, undulating south-facing slopes. The soil 

surface is rocky. The mean elevation (± standard deviation) 

of sample plots was 6,738 (±234) ft. Fuels on sites sampled 

were fine herbaceous materials with some dead stemwood. 

Other Studies-Singleleaf pinyon-curlleaf mountainmahogany-dominated vegetation is described by Heize and 

others (1962) from the Steptoe watershed in Nevada. The 

Singleleafpinyon-curlleafmountain-mahogany/Sandberg's 

bluegrass has not been described elsewhere. 

88 

Singleleaf Pinyon-Utah Juniper/Big 

Mountain Sagebrush/Bluebunch 

Wheatgrass Plant Association 

Distribution-Singleleafpinyon -Utahj uniperlbig mountain sagebrushlbluebunch wheatgrass (Pinus monophyllaJuniperus osteosperma / Artemisia tridentata vaseyana / 

Agropyron spicatum) was sampled on nine pl~ts located in 

the Jim Sage Mountains and in the northwestern and 

west-central Albion Mountains, at Jim Sage Canyon, Pine 

Knob, and Slide Canyon, respectively. 

Vegetation-This vegetation is rounded-crowned temperate or subpolar needle-leaved evergreen woodland (using 

national standards). Singleleafpinyon and Utahjuniper are 

co-dominant often with nearly equal cover. Stands are open, 

with a mix of medium to large sized mature trees and 

seedling, sapling and pole sized regeneration. Mountain big 

sagebrush is well represented in the relatively sparse shrub 

layer. Bluebunch wheatgrass is consistently well represented; Sandberg's bluegrass is present. 

Environment-Singleleaf pinyon-Utah juniper/big 

mountain sagebrushlbluebunch wheatgrass occurs on carbonate, felsic pyroclastic, and sandstone substrates. The 

plant association is located on lower and upper ridge spurs 

of mountainous terrain in ridge top and upper-slope microtopographical positions. Moderately steep slopes are undulating; north to northwest and east to southeast facing. The 

mean elevation (± standard deviation) of plots was 6,420 

(±589) ft. 

Other Studies-The plant association described here may 

be similar in part, or contained by, the singleleaf pinyonlUtah 

juniper (Pinus monophylla / Juniperus osteosperma) association described by Blackburn and others (1968a) for the 

Mill Creek watershed in north-central Nevada. Their stands 

are early- to mid-seral and are in a disturbed ecological 

condition. As well, geographical floristic change makes 

comparison difficult. The singleleaf pinyonlUtah juniper 

association described by Blackburn and others (1968b) for 

the Duckwater watershed, however, appears less similar. 

The association was identified by Caicco and Wellner (1983a 

and b) for City of Rocks and Jim Sage Canyon, Idaho (as 

reported by Grossman and others 1994). This plant association does not occur at the City of Rocks site. Rather, those 

stands are classified here as singleleaf pinyon-curlleaf 

mountain-mahogany/bush oceanspray/basin wildrye, 

singleleaf pinyon-curlleaf mountain-mahogany/mountain 

snowberry-Oregongrape/bluebunch wheatgrass, and 

singleleaf pinyon-curlleaf mountain -mahogany/Sandberg's 

bluegrass. The more refined singleleafpinyon-Utahjuniperl 

big mountain sagebrushlbluebunch wheatgrass plant association described here has not been described elsewhere. 

Singleleaf Pinyon-Utah Juniper/Bluebunch 

Wheatgrass Plant Association 

Distribution-Singleleaf pinyon -U tahj uni perlbl uebunch 

wheatgrass (Pinus monophylla-Juniperus osteosperma / 

Agropyron spicatum) was only observed in the Jim Sage 

Mountains, at Jim Sage Canyon RNA. Data was collected 

on seven plots. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Vegetation-The vegetation is an (rounded -crowned temperate or subpolar needle-leaved) evergreen woodland. Utah 

j uni per is the dominant tree species in the early-to mid -seral 

occurrences observed. Medium to large sized trees occur 

with moderate density. Singleleafpinyon and Utah juniper 

are present as seedling, sapling, and pole regeneration. 

Bluebunch wheatgrass is abundant in the open, parklike 

woodland. 

Environment-Singleleaf pinyon-Utah juniper/ 

bluebunch wheatgrass was only observed on felsic pyroclastic substrates. Sites are located on upper ridge spurs in 

mountainous terrain, on mid- to upper-slope micro-topographical positions. Slopes are primarily south- and southwest-facing, straight and relatively gentle. The soil surface 

is stony with fine, porous, continuous herbaceous fuels. The 

mean elevation (± standard deviatiqn) of sample plots was 

7,001 (±142) ft. 

Other Studies-The singleleafpinyonlUtahj uniperlblack 

sagebrushlbluebunch wheatgrass (Pinus monophylla/Juniperus osteosperma / Artemisia arbuscula nova / Agropyron 

spicatum) association described by Blackburn and others 

(1968a) for the Duckwater watershed in north-central Nevada is intermediate to singleleaf pinyon-Utah juniper/ 

bluebunch wheatgrass and singleleafpinyon-Utahjuniper/ 

black sagebrush/Sandberg's bluegrass (Pinus monophyllaJuniperus osteosperma / Artemisia arbuscula nova / Poa secunda) as described here. The singleleafpinyon-Utahjuniperlbluebunch wheatgrass plant association described here 

has not been described elsewhere. 

Singleleaf Pinyon-Utah Juniper/Black 

Sagebrush/Sandberg's Bluegrass Plant 

Association 

Distribution-Singleleaf pinyon-Utah juniperlblack 

sagebrush/Sandberg's bluegrass was observed in the Jim 

Sage Mountains and the northwestern Albion Mountains, at 

Jim Sage Canyon RNA and Pine Knob, respectively. Data 

were collected on nine plots. 

Vegetation-The vegetation is classified as roundedcrowned temperate or subpolar needle-leaved evergreen 

woodland. Singleleafpinyon and Utah juniper are co-dominant. Stands are open and moderately dense. Pole, sapling, 

and seedling sized singleleaf pinyon and U tahjuni per regeneration occurs in the understory of large and medium size 

trees. Understory shrub cover is sparse. Low sagebrush 

(Artemisia arbuscula arbuscula) and black sagebrush (Artemisia arbuscula nova) may both be present; the later species 

is consistently more abundant. Herbaceous cover is typically 

well represented; herbaceous species composition is not 

consistent. Bluebunch wheatgrass is often present, though 

not abundant. Sandberg's bluegrass is consistently well 

represented. 

Environment-Singleleaf pinyon-Utah juniperlblack 

sagebrush/Sandberg's bluegrass was observed on carbonate and sandstone substrates. Sites are located on lower 

ridge spurs in mountainous terrain, on mid-slope microtopographical positions. Dry east-, southeast-, south-, and 

southwest-facing slopes are straight and moderately 

USDA Forest Service Proceedings RMRS-P-9. 1999 

gentle. The stony soil surface is with fine, porous, continuous herbaceous fuels. The mean elevation (± standard deviation) of sample plots was 5,811 (±313) ft. 

Other Studies-The singleleafpinyonlUtahjuniperlblack 

sagebrushlbluebunch wheatgrass association described by 

Blackburn and others (1968a) for the Duckwater watershed 

in north-central Nevada is intermediate to singleleaf pinyon-U tahjuni perlblack sagebrush/Sandberg's bluegrass and 

singleleaf pinyon-Utah juniperlbluebunch wheatgrass as 

described here. The more refined singleleaf pinyon-Utah 

juniperlblack sagebrush/Sandberg's bluegrass plant association described here has not been described elsewhere. 

Utah Juniper Series 

In Idaho, Utah juniper-dominated woodlands occur in the 

South Hills, east to the Malad and Bannock ranges and 

north across the Snake River Plain to the southern end of the 

Lost River and Lemhi ranges. Stands were sampled at six 

sites within the southern portion of this distribution. Vegetation within the series ranges from open woodland to 

dwarf-shrubland and shrubland (almost grassland) with 

dispersed trees. Utah juniper-dominated woodlands occur 

on upper-slope and ridge top positions in mesa and moderate 

elevation mountainous terrain. Ten plant associations are 

recognized here. 

Utah Juniper-Curlleaf Mountainmahogany/Mountain Snowberry/ 

Bluebunch Wheatgrass Plant Association 

Distribution-Utah juniper-curlleaf mountain-mahogany/mountain snowberrylbluebunch wheatgrass was 

observed on the north end ofthe Bear River Range and in the 

Bannock Range. This plant association is probably more 

widely distributed and extensive, though it is represented 

here by only two plots. Sufficient data are not available to 

adequately describe the species composition and environmental relations ofthis apparently distinct plant association. 

Other Studies-DeVelice and Lesica (1993) describe 

Utah juniper-curlleaf mountain-mahogany-dominated 

vegetation from the Pryor Mountains of Carbon County, 

Montana. 

Utah Juniper/Mountain Snowberry/ 

Bluebunch Wheatgrass Plant Association 

Distribution-Utah juniper/mountain snowberry/ 

bluebunch wheatgrass (Juniperus osteosperma/ Symphoricarpos oreophilus / Agropyron spicatum) was observed in the 

South Hills, Jim Sage Mountains, and the Malad Range. 

This association may be present throughout the southern 

range of Utah juniper in Idaho. 

Vegetation-This vegetation is rounded-crowned temperate or subpolar needle-leaved evergreen woodland. An 

open canopy of medium- and large-sized Utah juniper typically occurs with moderate shrub cover and abundant grass 

cover. Mountain big sagebrush and mountain snowberry are 

89 
characteristic shrub species. Numerous herbs are observed 

on Utahjuni per/mountain snowberrylbl uebunch wheatgrass 

sites, few with great constancy. Lupine (Lupinus spp.) and 

prickly-pear are fairly constant. Bluebunch wheatgrass is 

usually abundant; Sandberg's bluegrass is often present. 

Environment-The plant association occurs on carbonate, felsic pyroclastic, and sandstone substrates. Utah 

juniper/mountain snowberrylbluebunch wheatgrass sites 

are on mesa and upper ridge spurs of moderately high mountainous terrain on mid- to upper-slope micro-topographical 

positions. Southeast-, south-, and southwest-facing slopes 

are straight and gentle. The mean elevation (± standard 

deviation) of sample plots was 6,798 (±413) ft. 

Other Studies-The Utahjuniper/mountain snowberry/ 

bluebunch wheatgrass plant association has not been described elsewhere. 

Utah JuniperlWyoming Big Sagebrush/ 

Needle-and-Thread Plant Association 

Distribution-Utah juniperlWyoming big sagebrush! 

needle-and-thread (Juniperus osteosperma/Artemisia tridentata wyomingensis / Stipa comata) was observed only in 

the Goose Creek drainage, adjacent Goose Creek Mesa RNA. 

It is expected that the plant association is more widely 

distributed; additional occurrences were not documented. 

The existing data essentially document a single stand; 

additional information is needed to describe the variability 

of this distinctive vegetation. 

Other Studies-Blackburn and others (1971) describe a 

similar plant association from stands located in the Rock 

Springs watershed, Nevada. 

Utah Juniper/Mountain Big Sagebrush/ 

Idaho Fescue Plant Association 

Distribution-Utah juniper/mountain big sagebrush! 

Idaho fescue (Juniperus osteosperma/Artemisia tridentata 

vaseyana/ Festuca idahoensis) was observed in the South 

Hills at both Trapper Creek and Goose Creek Mesa. It is 

expected to occur throughout the eastern portion of the 

South Hills, but with low areal extent. 

Vegetation-This is an evergreen microphyllus shrubland. The modal abundance oftrees is <25 percent cover and 

is less then the modal sum of shrub, herb, and grass abundance. Utah juniper/mountain big sagebrush!Idaho fescue 

stands are open, with an even (and relatively high) density 

of medium and large sized trees. Mountain big sagebrush is 

typically well represented. Bitterbrush is often present. 

Herbs are usually well represented; important species include arrowleaf balsamroot, Hood's phlox (Phlox hoodii), 

and prickly-pear. Bluebunch wheatgrass is often well 

represented. Idaho fescue (Festuca idahoensis) is usually 

abundant. 

Environment-The plant association was observed on 

felsic pyroclastic and sandstone substrates. Sites are located 

on mesa tops and upper ridge spurs of moderately high 

mountainous terrain, in ridge top and upper-slope microtopogra phi cal posi tions. N ortheast-facing slopes are straight 

90 

and gentle. The mean elevation (± standard deviation) of 

plots was 6,178 (±150) ft. 

Other Studies-The Utah juniper/mountain big sagebrushlIdaho fescue plant association has not been described 

elsewhere. 

Utah Juniper/Mountain Big Sagebrush/ 

Bluebunch Wheatgrass Plant Association 

Distribution-Utah juniper/mountain big sagebrush! 

bluebunch wheatgrass (Juniperus osteosperma/ Artemisia 

tridentata vaseyana/Agropyron spicatum) was observed in 

the southern South Hills, Malad Range, and Bannock Range. 

This plant association probably occurs at additional sites 

within these geographical extremes. 

Vegetation-This is a rounded-crowned temperate or 

subpolar needle-leaved evergreen woodland. Medium- and 

few large-sized Utah juniper contribute to a tree canopy of 

20-50 percent closure. Pole-, sapling-, and seedling-sized 

Utah juniper regeneration is moderately dense. Mountain 

big sagebrush is well represented, often with bitterbrush. 

Numerous herbs occur in these woodlands. Arrowleaf 

balsamroot is most constant, and often is abundant. 

Bluebunch wheatgrass is well represented to abundant. 

Environment-The plant association occurs on carbonate, felsic pyroclastic, and sandstone substrates. Sites are 

located on upper ridge spurs of moderately high mountainous terrain, in (ridge top) upper- to lower-slope microtopographical positions. Dry south- and west-facing slopes 

are moderately steep. The mean elevation (± standard deviation) of sample plots was 6,350 (±290) ft. 

Other Studies-The Utah juniper/mountain big sagebrushlbluebunch wheatgrass plant association has not been 

described elsewhere. 

Utah Juniper/Mountain Big Sagebrush/ 

Indian Ricegrass Plant Association 

Distribution-Utah juniper/mountain big sagebrush! 

Indian ricegrass (Juniperus osteosperma/ Artemisia tridentata vaseyana / Oryzopsis hymenoides) was only observed at 

Goose Creek Mesa. The plant association is expected to occur 

in similar habitats within the South Hills. 

Vegetation-This is a rounded-crowned temperate or 

subpolar needle-leaved evergreen woodland. Utah juniper 

tree canopy cover ranges from 20-40 percent. Very large-, 

large-, and medium-sized trees contribute to a moderate 

stem density of 10 trees per acre. Relatively little pole- and 

seedling-sized regeneration is present. Mountain big sagebrush and bitterbrush are common. Relatively few herbaceous species are observed; prickly phlox and basin-butterweed (Senecio multilobatus) are common and constant. 

Bluebunch wheatgrass, Sandberg's bluegrass, and Indian 

ricegrass (Oryzopsis hymenoides) are common and characteristic species. Bluebunch wheatgrass is most abundant. 

Environment-The plant association was observed on 

felsic pyroclastic and sandstone substrates. These sites are 

located in upper- and middle-slope micro-topographical positions within mesa terrain. Dry, southwest- and west-facing 

USDA Forest Service Proceedings RMRS-P-9. 1999 
slopes are straight and steep. Utah juniper/mountain big 

sagebrushlIndian ricegrass occurs on raveling colluvium; 

cobbles, stones, and gravel are abundant on the soil surface. 

The mean elevation (± standard deviation) of samples was 

6,070 (±106) ft. 

Other Studies-Blackburn and others (1968b) describe 

Utah juniperlbig sagebrushlIndian ricegrass from stands 

located in the Duckwater watershed, Nevada. Comparison 

is difficult as the authors describe early- to mid-seral stands 

typically in a disturbed ecological condition. 

Utah Juniper/Low Sagebrush/Idaho 

Fescue Plant Association 

Distribution-Utahjuniperllow sagebrushlIdaho fescue 

(Juniperus osteosperma/Artemisia -arbuscula arbuscula/ 

Festuca idahoensis) was sampled at Goose Creek Mesa and 

Trapper Creek. This plant association is expected to occur 

throughout the South Hills in Idaho. 

Vegetation-This vegetation is needle-leaved or 

microphyllus evergreen dwarf-shrubland with needle-leaved 

evergreen trees. Utahjuniperllow sagebrush/Idaho fescue is 

open woodlandldwarf-shrubland. Tree, low shrub, and grass 

components often occur in equal proportions. Observed very 

large-, large-, and medium-sized tree density was low to 

moderate (12 trees per acre), relative to other Utah juniper 

associations. Understory regeneration was relatively low, 

with an average of two trees per acre pole-, sapling-, and 

seedling-sized Utah juniper. Low sagebrush is well represented and often abundant in the understory with bitterbrush and black sagebrush. Numerous herbaceous species 

are observed; few are very constant. Cushion buckwheat 

(Eriogonum caespitosum) and prickly-pear are important 

herbs. Idaho fescue, Sandberg's bluegrass, and blue bunch 

wheatgrass are important grass species. Idaho fescue is 

usually well represented to abundant. 

Environment-The plant association was observed primarily on felsic pyroclastic substrate, but also on sandstone. 

Sites are located on basalt mesa tops, in ridge top and upperslope positions. Dry, well drained north- and southeastfacing slopes are straight, and gentle (or flat). The soil 

surface is gravelly. The mean elevation (± standard deviation) of sample plots was 6,312 (±110) ft. 

Other Studies-The Utahjuniperllow sagebrush/Idaho 

fescue plant association has not been described elsewhere. 

Utah Juniper/Low Sagebrush/Bluebunch 

Wheatgrass Plant Association 

Distribution-Utah juniperllow sagebrushlhluebunch 

wheatgrass (Juniperus osteosperma / Artemisia arbuscula 

arbuscula/Agropyron spicatum) was observed in the South 

Hills, Jim Sage Mountains, and Bannock Range. The association may also occur in the Cotterel Mountains, Sublett 

Range, and Deep Creek Mountains. 

Vegetation-This is rounded-crowned temperate or subpolar needle-leaved evergreen woodland vegetation. Observed very large-, large-, and medium-sized tree density 

USDA Forest Service Proceedings RMRS-P-9. 1999 

was low (nine trees per acre) relative to other Utah juniper 

associations. Understory regeneration is moderately high, 

with an average of seven trees per acre pole-, sapling-, and 

seedling-sized Utah juniper. The understory is occupied by 

abundant low shrubs, herbs, and grasses. Low sagebrush is 

consistently well represented to abundant. Mountain snowberry is usually present but not well represented. Arrowleaf 

balsamroot is consistently present and usually well represented. Prickly-pear is also an important herb. Bluebunch 

wheatgrass and Sandberg's bluegrass are both consistently 

present, the former being most abundant and well represented to abundant. 

Environment-The association was observed on felsic 

pyroclastic, mixed carbonate, and (primarily) sandstone 

substrates. Sites are located on mesa tops and upper ridge 

spurs of moderately high mountainous terrain, most frequently in upper-slope micro-topographical positions. Dry, 

southeast-, south-, and southwest-facing slopes are horizontally convex, vertically straight, and moderately gentle. 

Utah juniperllow sagebrushlhluebunch wheatgrass often 

occurs in association with fragmented bedrock. Large rock 

fragments (boulders, cobbles, and stones) occupy between 15 

and 45 percent cover. The mean elevation (± standard 

deviation) of sample plots was 6,577 (±292) ft. 

Other Studies-This association incorporates stands 

identified by Grossman and others (1994) as Utah juniper/ 

bitter-brush-mountain snowberrylbluebunch wheatgrass 

(Juniperus osteosperma / Purshia tridentata-Symphoricarpos oreophilus / Agropyron spicatum). The Utahjuniperllow 

sagebrushlhluebunch wheatgrass plant association has not 

been described elsewhere. 

Utah Juniper/Black Sagebrush/Bluebunch 

Wheatgrass Plant Association 

Distribution-U tahjuniperlblack sagebrushlhl uebunch 

wheatgrass (Juniperus osteosperma / Artemisia arbuscula 

nova/Agropyron spicatum) was observed in the Jim Sage 

Mountains and Bannock Range. This plant association is 

probably repeated in similar ridge top habitats in the Cotterel 

Mountains, Sublett Range, and Deep Creek Mountains but 

not with large, extensive occurrences. 

Vegetation-This vegetation is needle-leaved or 

microphyll us evergreen dwarf-shrub land with needle-leaved 

evergreen trees. Utah juniper large- and medium-sized 

trees occur with moderate density (15 trees per acre). Understory regeneration is relatively abundant (compared to other 

Utah juniper associations) with 15 trees per acre. The tree 

canopy is very open. Low shrubs, and grasses are abundant 

in the understory. Black sagebrush and low sagebrush are 

both present, the former dominant and well represented to 

abundant. Hood's phlox is a common and characteristic 

herb. Bluebunch wheatgrass and Sandberg's bluegrass are 

both consistently present. Bluebunch wheatgrass is well 

represented to abundant. 

Environment-The association was sampled primarily 

on felsic pyroclastic substrate, but also occurs on sandstone. 

Sites are located on upper ridge spurs of moderately high 

mountainous terrain, most frequently in upper-slope microtopographical positions. The mean elevation (± standard 

91 
deviation) of sample plots was 7,120 (±211) ft. Gentle, dry, 

well drained, south- and west-facing slopes are horizontally 

convex and vertically straight. Cobbles and stones are well 

represented to abundant. 

Other Studies-The broadjuniperwoodland community 

identified by Knight and others (1987) for Bighorn Canyon 

National Recreation Area, Wyoming, is similar to (or contains) the Utah juniperlblack sagebrushlbluebunch wheatgrass plant association described here. Blackburn and others(1971)describe Utahjuniperlblacksagebrushlbluebunch 

wheatgrass as occurring in the Rock Springs watershed, 

Nevada. Utahjuniper is less abundant (8.8 versus 11.5-16.4 

percent cover) and black sagebrush and bluebunch wheatgrass are more abundant (20 versus 6.1-7.8 and 32 versus 

3.8 percent cover, respectively) in reference area stands 

compared to the seral, disturbed Rock Spring stands. Caicco 

and Wellner (1983c) identify the assoCiation as occurring in 

the southern Lemhi Range. Bourgeron and Engelking (1994), 

however, group the southern Lemhi Range stands in the 

broader Utah juniperlblack sagebrush (Juniperus osteosperma I Artemisia arbuscula nova). 

Utah Juniper/Black Sagebrush/Sandberg's 

Bluegrass Plant Association 

Distribution-Utahj uni perlblack sagebrush/Sandberg's 

bluegrass (Juniperus osteosperma I Artemisia arbuscula 

noval Poa secunda) was observed in the South Hills. The 

extent of the association within the area and adjacent 

areas is not known. 

Vegetation-This vegetation is needle-leaved or 

microphyll us evergreen dwarf-shrubland with needle-leaved 

evergreen trees. Utahjuniper canopy cover ranges from 1-25 

percent. Dwarf-shrub species are the dominant life form. 

Black sagebrush is usually abundant; low sagebrush is often 

present. Slenderbush buckwheat (Eriogonum microthecum), 

cushion buckw heat, and Hooker's balsamroot (Balsamorhiza 

hookeri) are common and characteristic herbs. Sandberg's 

bluegrass is consistently well represented. 

Environment-Utahjuniperlblacksagebrush/Sandberg's 

bluegrass was only observed on felsic pyroclastic substrates. 

Sites are located on mesa tops, most frequently in ridge top 

micro-topographical positions. Gentle slopes occur with a 

range of aspects and micro-configurations. The mean elevation (±standard deviation) of sample plots was 6,430 (±89) ft. 

These sites are very rocky. Large- to medium-sized rock 

fragments (cobbles, stones, and gravel) may occupy 45-70 

percent of the surface. 

Other Studies-The Utahjuniperlblack sagebrush/rock 

(Juniperus osteosperma I Artemisia arbuscula novalRock) 

plant association described by Blackburn and others (1968b) 

for the Duckwater watershed, Nevada, is similar to Utah 

juniperlblack sagebrush/Sandberg's bluegrass plant association described here. 

Conclusions -------------------------------

Research Natural Areas are identified and established to 

provide a baseline reference for evaluation of intensive 

92 

resource management affects. This paper presents an initial classification of pinyon-juniper vegetation observed in 

Research Natural Areas of southeastern Idaho. The 

composition, distribution, and environmental relations of 

23 pinyon-juniper plant associations is summarized. This 

information provides a baseline for conservation planning 

and ecosystem management. 

The results of this study assist with the identification and 

description of reference stand conditions in pinyon-juniper 

woodland vegetation of the northern Great Basin region. 

Determination of the relationships of plant associations 

identified here to similar vegetation within the region is (in 

some cases) difficult due to the availability and presentation 

of existing information. These questions will be resolved as 

more work from within the region becomes available. The 

data presented here, as well, need further testing within the 

subregional scale ofthe study area. These developments will 

make important contributions to determination of the conservation status of pinyon-juniper woodland vegetation of 

the northern Great Basin region. 

Acknowledgments 

This project was conducted through cooperative agreements between Idaho Department ofFish and Game; Burley 

Field Office, Bureau of Land Management; and USDA Forest Service, Rocky Mountain Research Station. Thanks to 

Jim Tharp, Paul Makela, John Augsburger, and Bob Moseley 

for their logistical support and review of initial drafts ofthis 

paper. Thanks to Angela Evenden and Alma Winward for 

their support of the identification and use of ecological 

reference areas. 

References _________ _ 

Baker, W. L. 1984. A preliminary classification of the natural 

vegetation of Colorado. The Great Basin Naturalist 44(4): 

647-676. 

Blackburn, W. H.; Tueller, P. T.; Eckert, R. E. Jr. 1968a. Vegetation 

and soils of the Mill Creek Watershed. Nevada Agricultural 

Experiment Station Bulletin R-43. Reno. 69 p. 

Blackburn, W. H.; Tueller, P. T.; Eckert, R. E. Jr. 1968b. Vegetation 

and soils of the Duckwater Watershed. Nevada Agricultural 

Experiment Station Bulletin R40. Reno. 76 p. 

Blackburn, W. H.; Eckert, R. E. Jr.; Tueller, P. T. 1969. Vegetation 

and soils of the Churchill Canyon Watershed. Nevada Agricultural Experiment Station Bulletin R-45. Reno. 157 p. 

Blackburn, W. H.; Eckert, R. E. Jr.; Tueller, P. T. 1971. Vegetation 

and soils of the Rock Springs Watershed. Nevada Agricultural 

Experiment Station Bulletin R-83. Reno. 116 p. 

Bourgeron, P. S.; DeVelice, R. L.; Engelking, L. D.; Jones, G.; 

Muldavin, E. 1991. WHTF site and community survey manual. 

Version 92B. Western Heritage Task Force, Boulder. 24 p. 

Bourgeron, P. S.; Engelking, L. D. 1994. A preliminary vegetation 

classification of the Western United States. The Nature Conservancy, Western Heritage Task Force, Boulder. 

Caicco, S. L.; Wellner, C. A. 1983a. Research Natural Area recommendation for City of Rocks. Unpublished report prepared for 

USDI, Bureau of Land Management, Burley District, Idaho by 

Idaho Natural Areas Coordinating Committee. On file at Idaho 

Conservation Data Center, Boise, Idaho. 12 p. 

Caicco, S. L.; Wellner, C. A. 1983b. Research Natural Area recommendation for Jim Sage Canyon, BLM, Burley District, ID. 

Unpublished report prepared for USDI, Bureau of Land Management, Burley District by Idaho Natural Areas Coordinating 

Committee. On file at Idaho Conservation Data Center, Boise, 

Idaho. 12 p. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Caicco, S. 1.; Wellner, C. A 1983c. Research Natural Area recommendation for Southwest Lemhi Range. Unpublished report 

prepared for USDI, Bureau of Land Management, Burley District 

by Idaho Natural Areas Coordinating Committee. On file at 

Idaho Conservation Data Center, Boise, Idaho. 14 p. 

Cronquist, A; Holmgren, A H.; Holmgren N. H.; Reveal, J. 1. 1972. 

Intermountain flora: vascular plants of the Intermountain West, 

USA Vol. 1. Hafner Publishing Company, Inc., New York. 270 p. 

Cooper, S. V.; Lesica, P.; McGarvey, J. T. 1995. Classification of 

southwestern Montana plant communities with emphasis on 

those of Dillon Resource Area, Bureau of Land Management. 

Montana Natural Heritage Program, Helena, MT. 152 p. 

DeVelice, R. L.; Lesica, P. 1993. Plant community classification for 

vegetation on BLM lands, Pryor Mountains, Carbon County, 

Montana. Montana Natural Heritage Program, Helena, MT. 78 p. 

Federal Geographic Data Committee-Vegetation Subcommittee. 

1996. Vegetation Classification and Information Standards. USDI, 

Geological Survey, Reston. 35 p. 

Grossman, D. H.; Goodin, K. 1.; Reuss, C. L., editors. 1994. Rare 

plant communities of the coterminous United States - an initial 

survey. Prepared for the USDI Fish and Wildlife Service. The 

Nature Conservancy, Arlington, VA 620 p. 

Heize, D. H.; Eckert, R. E.; Tueller, P. T. 1962. The vegetation and 

soils of the Steptoe Watershed. Unpublished report prepared for 

the USDI Bureau of Land Management. 40 p. 

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and Roosevelt National Forests in north central Colorado: A 

habitat type classification. USDA Forest Service Research Paper 

RM-266. Rocky Mountain Forest and Range Experiment Station, 

Ft. Collins, CO. 48 p. 

Hill, M. O.1979a. DECORANA-a FORTRAN program for detrended 

correspondence analysis and reciprocal averaging. Ecology and 

Systematics, Cornell University, Ithaca. 36 p. 

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Hill, M. O. 1979b. TWINS PAN-a FORTRAN program for arranging multivariate data in an ordered two-way table by classification of individuals and attributes. Ecology and Systematics, 

Cornell University, Ithaca. 60 p. 

Johnston, B. C. 1987. Plant associations of Region Two. Edition 4. 

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429 p. 

Knight, D. H.; Jones, G. P.; Akashi, Y.; Myers, R. W. 1987. Vegetation ecology in the Bighorn Canyon National Recreation Area. 

Unpublished report prepared for the USDI National Park Service 

and the University of Wyoming-Nat. Park Service Research 

Center. 114 p. 

McNab, W. H.; Avers, P. E., comps. 1994. Ecological subregions of 

the United States: Section Descriptions. Administrative Publication WO-WSA-5. Washington, DC: U.S. Department of Agriculture, Forest Service. 267 p. 

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and guide. USDA Forest Service, Pacific Northwest Region, 

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Wageningen, The Netherlands. 95 p. 

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1987 National Natural Landmark Project, Pacific Northwest 

Region, National Park Service; Including classification of the 

following ecological themes: Western Juniper, Utah and Rocky 

Mountain Juniper Woodlands, Lowland and Valley Grassland, Canyon Grasslands, and Montane Coastal Refugium 

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Guide (7/92). Northern Region, Missoula, MT. 

93 
Tree Size and Ring Width of Three Conifers 

in Southern Nevada 

Simon A. Lei 

Abstract-The sizes and ring widths of singleleaf pinyon, ponderosa pine, and white fir were investigated along an elevational 

gradient in the Spring Mountain Range of southern Nevada. The 

mean height and stem diameter of ponderosa pine were generally 

taller and larger relative to singleleaf pinyon and white fir. All 

three conifers exhibited greater mean stem diameter on northfacing relative to south-facing slopes. Ring widths from trees on 

lower elevations were most variable. The ~idest rings were generally formed on south-facing slopes, while the narrowest rings were 

formed on north-facing slopes. Differences in tree sizes and ring 

widths were a function of variations in climate, elevations, and slope 

exposures in the Spring Mountain Range of southern Nevada. 

The singleleaf pinyon-Utah juniper (Pinus monophyllaJuniperus osteosperma) woodland ranges from approximately 

1,250 to 2,600 m in elevation on dry mountain slopes in 

southern Nevada. On south-facing slopes, the woodland is 

generally more open, Utah juniper predominates and the 

understory vegetation consists of mixed shrubs with some 

grasses. On north-facing slopes, the canopy is largely closed, 

singleleafpinyon predominates and the understory is mostly 

of grasses. The montane ponderosa pine-white fir (Pinus 

ponderosa-Abies concolor) forest ranges from approximately 

2,200 to 2,900 m in elevation in the Spring Mountains of 

southern Nevada. The pinyon-juniper woodland and ponderosa-fir forest are considered climax species because they 

maintain relatively stable populations without progressive 

replacement by other woody taxa (Luken 1990). 

The greatest changes in tree characteristics of conifers 

growing on relatively high desert mountain slopes are related to the topographic and elevational differences in the 

site (Fritts 1976, 1991). The significance of topography and 

slope exposure is due to the influence on the moisture, air 

temperature, incident radiation, and orientation of prevailing wind regimes, which may become limiting to the growth 

of trees (Schweingruber 1989; Fritts 1965, 1991). Fritts 

(1969) proposed that on the dry south-facing exposures, 

some tree rings are absent or partially present, the pattern 

of ring widths is strongly correlated within and between 

trees, and chronologies are more variable. The environment 

is most limiting to ring-width growth at low elevational 

sites, particularly on south-facing slopes in the White 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Simon A. Lei is a Biology and Ecology Professor at the Community 

College of Southern Nevada, 6375 West Charleston Boulevard, W2B, 

Las Vegas, Nevada 89102-1124. 

94 

Mountains of southern California (Fritts 1969). Subtle differences in relief, slope exposure, microclimate, and soil 

properties would lead to changes in stand density and 

composition. 

A correlation existed between precipitation and ring 

widths of trees growing on arid or low elevational sites 

(Fritts 1976, 1991). Chronologies are not always easily dated 

beca use many rings may be small, or in extremely arid years, 

the cambium may fail to grow and no ring is formed 

(Fritts 1969). Tree-ring chronologies from lower elevations, 

south-facing slopes, and from areas ofless snow accumulation exhibit the most chronologic variability and contain the 

most information regarding past climates in southern 

California (Fritts 1969, 1991). Drought reduces net photosynthesis, which limits the accumulation of reserved food. 

With less food, growth is slow and a narrow ring is formed 

(Fritts 1969, 1991). Dry conditions due to high air temperatures or low precipitation of late summer or autumn may 

also reduce the amount of accumulated food, and thus 

influence the width of the following season's ring (Fritts 

1969, 1976). Severe drought influences tree ring characteristics, including ring widths for several years, and drought 

can even cause the tree mortality. 

Three common conifers-singleleaf pinyon, ponderosa 

pine, and white fir-occupy relatively high desert mountain 

slopes in the Spring Mountain Range of southern Nevada. 

The objectives of this study were to quantitatively examine 

the tree size, ring width, and to correlate variations in ring 

width of three conifer species with variations in elevation, 

climatic parameters, and slope exposures in Lee Canyon of 

southern Nevada. 

Methods ------------------------------------

Study Area 

Field studies were conducted in spring 1996 in Lee Canyon (36°05' N, 115°15' W; elevation 2,000 to 2,900 m) of the 

Spring Mountains, located approximately 50 km northwest 

of Las Vegas, Nevada (fig. 1). Lee Canyon was chosen based 

on the accessibility to the pinyon-juniper woodland and 

montane ponderosa-fir forest. The tree samples were obtained from sites representing differences in climate, elevation, and slope exposure. The pinyon-juniper woodland is 

found at elevations ranging from 1,250 to 2,600 m in the 

Spring Mountains. Vegetation is characterized by Utah 

juniper, singleleafpinyon, and big sagebrush. The montane 

ponderosa-fir forest extends from approximately 2,150 to 

2,900 m. This montane forest consists ofa mixture ofponderosa pine, white fir and, to a lesser extent, limber pine (Pinus 

flexilis) and quaking aspen (Populus tremuloides). The narrow drainage has an eastern descent with steep slopes 

having north and south aspects. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
N 

I 

Nevada 

"" Lee Canyon 

Spring Mountains~ ~ . Las Vegas 

~nia 

'L_. __ --rUtah 

Arizona 

o 100 200 I , I 

Kilometers 

Figure 1-Map of the study area showing Lee Canyon 

of the Spring Mountains located in the southwestern 

United States. The city of Las Vegas lies to the southeast of the Spring Mountains. 

The winter climate of pinyon-juniper woodland and ponderosa-fir forest is cold with frequent snowfall, while the 

summer climate is cool. The temperature and precipitation 

data in southern Nevada were acquired from the nearest 

long-term weather station (record of climatological observations; National Weather Service) in Kyle Canyon, located 

approximately 15 km from Lee Canyon. Air temperatures 

were frequently in the subzero range from December through 

early April. At 2,000 m elevation and above, summer temperatures are cool and rarely surpass 30 oC, while in the 

winter, snow and below-freezing temperatures are common. 

Minimum air temperatures on the average are above freezing from June through September, and minimum temperatures during winters are seldom below-25 °C. Occasionally, 

snow is present at higher elevations in midsummer. Precipitation varies considerably from year to year. Annual precipitation of the pinyon-juniper woodland is generally less than 

400 mm, and montane ponderosa-fir woodland ranges from 

300 to over 600 mm. This variation in precipitation is largely 

related to a combination of topography, elevation, and slope 

exposure. Most of the precipitation occurs in winter storms 

or in late summer thunderstorms in southern Nevada. 

Field Surveys 

Two (150 m * 150 m) square plots were established at each 

of the 10 elevations along a gradient ranging from 2,000 to 

2,900 m with a fixed elevational interval of100 m. A total of 

20 plots were evenly distributed on both north- and southfacing slopes. Some pine and fir saplings were detected along 

this elevational gradient but were not measured. Saplings 

were generally more abundant on the north-facing than 

south-facing slopes. Living barks completely encircled the 

USDA Forest Service Proceedings RMRS-P-9. 1999 

stems (full bark) in many trees. I cored through at least 

one-half of the stem diameters of the trees containing pith. 

Trees were selected from north- and south-facing exposures 

only for intensive study. Some partial rings were formed, 

especially at the lower elevational (arid) sites. For this 

reason, four incremental cores were extracted systematically based on four compass directions (north, south, east, 

and west) along the radii from each tree at breast height to 

reduce tree-ring error and to allow analysis ofthe variations 

within trees. Cores were extracted without major faults, 

such as fire scars, rotten spots, frost cracks, insect damage, 

and woodpecker holes. The trees were selected from a relatively small homogenous group to minimize variability arising from diverse soil types and factors. The yearly ring 

widths were crossdated among all radii within a stem and 

among different trees in sampled stands. The tree-ring 

widths of singleleaf pinyon, ponderosa pine, and white fir 

were determined with the aid of a stereoscope and a millimeter ruler after extracting cores from tree stems. One ring 

was assumed to equal 1 year's growth. Only rings for the 

past 15 years were examined. Height and stem diameter 

(d.b.h. or 1.5 m from the ground) of each tree were measured. 

Tree height was estimated by triangulation. 

Statistical Analyses 

One-way Analysis of Variance (ANOV A) was used to 

detect differences in tree characteristics (height and stem 

diameter) along the elevational gradient. ANOVA was also 

employed to detect differences in mean ring widths within a 

tree stem, between low and high elevational sites, and 

between different slope exposures. A Tukey's multiple 

comparison test was used to compare the mean height and 

stem diameter of three conifer species from the same elevation on both slope aspects, and to compare mean ring 

widths when significant slope and elevation effects were 

detected. Pearsons correlation analysis was conducted to 

correlate variations in ring widths of three conifer species 

with variations in abiotic (climate, elevation, and slope 

exposure) factors. Mean values in ring width were expressed 

with standard errors, and statistical significance was determined at p::; 0.05 (Analytical Software 1994). 

Results --------------------------------- From casual observations, both singleleaf pinyon and 

ponderosa pine exhibited relatively little regeneration, while 

white fir was the dominant understory species present 

within the study area. In general, ponderosa pine trees had 

a significantly larger stem diameter (p < 0.001; tables 1 

and 2) than white fir and singleleafpinyon. All three conifer 

species showed larger stem diameters on north-facing than 

on south-facing slopes. Ponderosa pine trees were significantly (p < 0.001) taller than white fir and singleleafpinyon 

on both slope exposures. Both white fir and ponderosa pine 

had significantly greater mean diameter, and were significantly taller than singleleaf pinyon regardless of slope 

exposures (p < 0.001; tables 2 and 3). 

The widest rings were detected in trees establishing on the 

south-facing slopes. Trees establishing on the south-facing 

slopes displayed more missing and partial rings with more 

95 
96 

Table 1-Total abundance (number of individuals), mean stem diameter (d.b.h.), and mean height of three conifer species establishing on the north-facing slopes from elevations of 2,000 to 2,900 m in the Spring Mountains. Mean values in rows under the 

same category (diameter and height) followed by different letters are significantly different at p ~ 0.05. 

Total abundance Stem diameter Height 

Elevation Pinyon Ponderosa Fir Pinyon Ponderosa Fir Pinyon Ponderosa Fir 

m - - - - - - - - - -cm - - - - - - - - - - -----------m-----------

2,000 79 46.7 20.3 

2,100 66 46.1 21.4 

2,200 62 12 9 48.2a 65.3b 67.2b 21.7a 37.1b 38.4b 

2,300 49 20 17 57.8a 68.1b 75.6c 25.8a 42.9b 38.7b 

2,400 37 15 41 55.2a 73.7b 74.9b 23.7a 46.5c 42.1b 

2,500 29 10 91 50.1a 77.2c 72.8b 23.6a 48.5c 42.9b 

2,600 12 19 108 47.3a 77.7c 67.6b 22.7a 45.9c 40.5b 

2,700 17 69 83.9a 74.4b 47.4a 39.9b 

2,800 12 32 81.4a 71.3b 45.1a 38.9b 

2,900 8 102 69.1a 78.4b 44.2a 37.4b 

Table 2-Total abundance (number of individuals), mean stem diameter (d.b.h.), and mean height of three conifer species establishing on the south-facing slopes from elevations of 2,000 to 2,900 m in the Spring Mountains. Mean values in rows under the 

same category (diameter and height) followed by different letters are significantly different at p ~ 0.05. 

Elevation 

m 

2,000 

2,100 

2,200 

2,300 

2,400 

2,500 

2,600 

2,700 

2,800 

2,900 

Total abundance Stem diameter Height 

Pinyon Ponderosa Fir Pinyon Ponderosa Fir Pinyon Ponderosa Fir 

- - - - - - - - - -cm - - - - - - - - - - -----------m-----------

69 42.3 20.1 

51 43.0 18.3 

63 12 37 41.9a 73.6b 75.7b 21.5a 

72 20 17 43.1a 68.1b 73.5c 19.8a 

51 12 9 46.4a 65.3b 67.2b 18.2a 

14 8 45 42.2a 78.3c 69.0b 19.4a 

6 7 149 47.7a 74.2b 79.9c 17.7a 

2 44 81.9a 72.0b 

7 14 74.8a 77.0a 

2 5 72.5a 65.8b 

Table 3-Relative ring widths (mean ± SE) of singleleaf pinyon, ponderosa pine, and white fir 

in the Spring Mountains. Low elevational sites included 2,000 to 2,300 m in the 

pinyon-juniper woodland, while 2,200 and 2,500 m in the montane ponderosa-fir 

forest. Mean values in columns followed by different letters are significantly different 

at p ~ 0.05. 

Sample 

North-facing slope 

Low elevation 

High elevation 

South-facing slope 

Low elevation 

High elevation 

Ring width (mm) 

Singleleaf pinyon Ponderosa pine White fir 

- - - - - - - - - - - - - - - - - - - - - - mm - - - - - - - - - - - - - - - - - - - - - -

0.78 ± 0.05 a 

0.66 ± 0.04 b 

0.86 ± 0.08 a 

0.72 ± 0.07 b 

0.80 ± 0.07 a 

0.54 ± 0.05 b 

0.87 ± 0.06 a 

0.64 ± 0.05 b 

1.19 ± 0.09 a 

0.97 ± 0.05 b 

1.35 ± 0.11 a 

1.04 ± 0.06 b 

37.1b 38.4b 

42.3b 40.7b 

46.5c 42.3b 

48.5c 43.9b 

45.8c 39.5c 

51.4a 39.4b 

46.9a 38.6b 

45.4a 38.9b 

USDA Forest Service Proceedings RMRS-P-9. 1999 
variations in ring widths regardless of species (data not 

shown). On the contrary, the narrowest rings were generally detected in trees on north-facing slopes (table 3). In this 

study, 2,000 to 2,300 m were regarded as low elevational 

sites in the pinyon-juniper woodland, while 2,200 to 2,500 m 

represented low elevational sites in the montane ponderosa-fir forest. Within the same slope aspect, ring width 

from trees existing on low elevational sites was wider and 

more variable compared to trees existing on high elevational 

sites (table 3). Among the three conifers, white fir showed 

the greatest ring width. Variations in ring widths reflected 

differences in elevation, climatic variables, and slope aspects (table 3). 

No significant differences (p > 0.05) were detected in 

ring widths within the tree stem in all three conifer species 

although some trees exhibited slight ring-width variations. 

A sharp boundary occurred between rings on stems, and the 

ring boundary represented the abrupt change in cell size 

between two growing seasons. Moreover, ring widths of 

three conifer species exhibited a significant positive correlation with mean annual air temperature, but exhibited a 

significant negative correlation with elevation, mean annual precipitation, and slope exposure (table 4). Narrow 

rings were significantly correlated with low air temperatures and high precipitation. 

Discussion ----------------------------------- Sizes and ring widths of singleleaf pinyon, ponderosa 

pine, and white fir trees on relatively high desert mountain 

slopes were examined at Lee Canyon in Spring Mountains of 

southern Nevada. White fir dominated on both slope aspects 

in the mixed ponderosa-fir vegetation zone. The ring widths 

oftrees near the species' lower elevationallimits would yield 

the most reliable climatic information. Tree-ring width and 

growth are chiefly dependent upon environmental factors, 

such as variations in elevation, topography, temperature, 

precipitation and slope exposure in southern Nevada. 

Topography and slope exposure modify incident radiation, air temperature, wind pattern, and soil moisture which 

may indirectly limit the growth of trees. On the moist, cool 

north-facing slope where denser stands of pine and fir trees 

occur, chronologies including ring width are less variable, 

fewer rings are absent, and contained the least amount of 

information on past climates in southern California (Fritts 

1969). Large differences in tree-ring characteristics associated with variation in topography and slope exposure are 

evident. If the sites are less extremes, the rings do not vary 

greatly in width, and ring-width variability is a function of 

site aridity (Fritts 1976, 1991), which corresponds with my 

study. Fritts (1976, 1991) further suggested that slope 

exposure, degree of slope, and orientation to prevailing wind 

are prime factors controlling moisture relations and ringwidth patterns in bristlecone pine (Pinus longaeva) in the 

White Mountains of California. 

A correlation existed between ring widths and moisture 

conditions of the previous summer and autumn, as well as 

temperature of the winter (Fritts 1991). Narrow rings were 

found to be correlated with climatic conditions, such as low 

air temperatures and high precipitation (LaMarche 1976). 

At low elevations and latitudes, variations in ring width 

often are highly and positively correlated with variations 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Table 4-Results of Pearsons correlation analysis 

by matching the ring widths of singleleaf 

pinyon, ponderosa pine, and white fir to 

abiotic factors. Air temperature and precipitation were averaged over an interval of 1 year. r is the coefficient of linear 

correlation. Significance levels: *:p < 

0.05, **: p < 0.01, ***:p < 0.001, and NS: 

non-significant. 

Factor 

Singleleaf pinyon 

Elevation 

Annual Temperature 

Annual Precipitation 

Slope exposure 

Ponderosa pine 

Elevation 

Annual temperature 

Annual precipitation 

Slope exposure 

White fir 

Elevation 

Annual temperature 

Annual precipitation 

Slope exposure 

-0.91'" 

0.88'" 

-0.85'" 

-0.93'" 

0.90'" 

-0.89'" 

-0.83'" 

-0.92'" 

0.8T" 

-0.86'" 

-0.74'" 

in precipitation and negatively correlated with variations in 

air temperature (Fritts 1976). However, at high elevations 

and latitudes, correlation between ring width with precipitation becomes weak and negative, while correlation between ring width and air temperature becomes strong and 

positive (Fritts 1976). 

Moreover, crossdating, including examining yearly ring 

widths among all radii within a stem and matching of ringwidth patterns among trees, is necessary because the same 

or similar environmental conditions have limited the ring 

widths in large number of trees. The year-to-year fluctuations in limiting environmental factors that are similar 

throughout an area appears to produce synchronous variations in ring structure (Fritts 1976). The fact that crossdating can be obtained is evidence that some climatic or 

environmental information were common to the sampled 

trees from a particular stand (Fritts 1976). 

Precipitation in the pinyon-juniper and montane ponderosa-fir vegetation zones is usually in the form of snow, and 

freezing air temperatures in winters are frequent as elevation ascends. When spring arrives, the melting snow pack 

seeps into the ground and serves as moisture for plants 

(Lei 1994). The precise ages of pine and fir trees were 

difficult to determine because they exhibited little or no net 

growth during extremely arid spring seasons with more 

missing and partial rings and more chronologic variation. 

Nevertheless, two fairly abundant seasonal rainfalls may 

lead to two distinct tree-ring growth within a single year. 

In order to accurately determine the absolute ages of pine 

and fir trees, distinct annual rings must be present from an 

active growing season. For these reasons, the absolute ages 

of pine and fir trees were not determined in this study. 

Furthermore, extreme drought during the most active 

growing period in May and June would limit photosynthesis 

and would highly correlate with narrow rings of trees 

97 
(McGinnies 1963). On the contrary, drought in late summer 

and autumn appear to have less correlation with narrow 

rings oftrees (McGinnies 1963). The influence ofa favorable 

or unfavorable year may be observed in not only the current 

tree-ring width, but also in the ring widths for the following 

3 years in northern Arizona (Fritts and others 1965; BaIlie 

1982; Stokes 1974). 

Schulman (1956) suggested that rates of photosynthesis is a function of air temperature. Mean annual air 

temperatures decrease with ascending elevation in southern Nevada (Lei 1994, 1995). The severity of winter air 

temperatures may influence photosynthesis in trees growing at high elevations. Cold winters may result in a prolonged inactive period and in a depletion of food reserves 

(Schulman 1941, 1956). While air temperatures during the 

winter may limit growth, air temperatures at other seasons 

interact with the moisture regime to produce differences in 

net photosynthesis, food reserves, and ring-width growth 

(Fritts 1969). On the more mesic, north-facing slopes, the 

physiological processes, such as photosynthesis, respiration, and cambial activity, are not as frequently limited by 

climate, and therefore the tree-ring widths are less variable 

in northern Arizona (Fritts and others 1965). Trees on the 

moist sites formed denser stands and were generally taller 

since moisture stress was less directly related to tree-growth 

responses. 

Implications and Future 

Directions ---------------------------------- The results of this study reveal that tree size and ring 

width can be utilized to examine the growth response of 

various tree species to their environment. Ring widths from 

trees are positively correlated with air temperature, while 

negatively correlated with elevation, precipitation, and slope 

exposure. Ring width variability is indicative of environmental stress of the tree site. Subtle or significant climatic 

change at the local and regional scales in the future would 

influence the density and abundance of both pine and fir 

trees. Once ring width chronologies in the pinyon-juniper 

and ponderosa-fir vegetation zones are developed from progressively drier sites and properly dated, one can provide an 

accurate, long-term record of climatic patterns. When the 

climatically "sensitive" arid-site trees with some partial 

rings are appropriately dated, their ring-width chronology 

may be used to analyze, characterize, and reconstruct the 

climatic fluctuations of the past in southern Nevada. 

98 

Acknowledgments 

Valuable field assistance provided by Steven Lei, David 

Valenzuela, and Shevaum Valenzuela was gratefully acknowledged. Climatic records of Lee Canyon of southern 

Nevada provided by Steven Brittingham was deeply 

appreciated. Helpful comments by David Charlet and 

Leslie Thomas greatly improved the manuscript. 

References --------------------------------- Analytical Software. 1994. Statistix 4.1, an interactive statistical 

program for microcomputers. Analytical Software, Minnesota. 

329 p. 

Ballie, M. G. L. 1982. Tree-ring dating and archaeology. University 

of Chicago Press, Chicago, Illinois. 274 p. 

Conkle, T. M. 1970. Growth data for 29 years from the California 

elevational transect study of ponderosa pine. Forest Science. 19: 

31-39. 

Fritts, H. C., D. G. Smith, J. W. Cardis, and C. A. Budelsky. 1965. 

Tree-ring characteristics along a vegetational gradient in northern Arizona. Ecology. 46: 393-401. 

Fritts, H. C. 1969. Bristlecone pine in the White Mountains of 

California. The University of Arizona Press, Tucson, Arizona. 

44 p. 

Fritts, H. C. 1976. Tree Rings and Climate. Academic Press, 

New York. 567 p. 

Fritts, H. C. 1991. Reconstructing Large-scale Climatic Pattern 

from Tree-Ring Data. The University of Arizona Press, Tucson, 

Arizona. 286. p. 

LaMarche, V. C. 1974. Paleoclimatic inferences from long tree-ring 

records. Science. 183: 1043-1048. 

Lei, S. A. 1994. Plants of the North American deserts. Unpublished 

research report, University of Nevada, Las Vegas, Nevada. 64 p. 

Lei, S. A. 1995. A gradient analysis of Coleogyne communities in 

southern Nevada. Unpublished masters thesis, University of 

Nevada, Las Vegas, Nevada. 117 p. 

Lewis, T. E. 1995. Tree rings as indicators of ecosystem health. CRC 

Press, Boca Raton, Florida. 210 p. 

Luken, J. 1990. Directional Ecological Succession. Chapman and 

Hall, London, United Kingdom. 251 p. 

McGinnies, W. G. 1963. Dendrochronology. Journal of Forestry. 

61: 5-11. 

Schulman, E. 1941. Some propositions in tree-ring analyses. 

Ecology. 22: 193-195. 

Schulman, E. 1956. Dendroclimatic changes in semiarid America. 

University of Arizona Press, Tucson, Arizona. 142 p. 

Schweingruber, F. H. 1989. Tree Rings. Kluwer Academic Publishers, Boston, Massachusetts. 276 p. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Host-Parasite Relationship Between Utah 

Juniper and Juniper Mistletoe in the Spring 

Mountains of Southern Nevada 

Simon A. Lei 

Abstract-The infection of Utah juniper by parasitic juniper 

mistletoe was quantitatively investigated at a blackbrush-Utah 

juniper ecotone in Pine Creek of southern Nevada. Juniper 

mistletoes significantly reduced the vigor, viability, and reproductive success of their host. The abundance of juniper mistletoe was 

significantly and positively correlated -with the height of Utah 

juniper. Diurnal and seasonal leaf water potentials of juniper 

mistletoe were significantly lower than leaf water potentials of 

adjacent, uninfected juniper trees. Heavy mistletoe infestation 

significantly increased host-plant water stress, and low host-plant 

water potentials might limit long-term mistletoe infection success. 

Infestation was beneficial for juniper mistletoe but harmful to 

Utah juniper. 

Mistletoes (Phoradendron spp.) are dwarfhemiparasites 

which once established, rely entirely upon their hosts for the 

supply of water and mineral nutrients (Hollinger 1983). 

Juniper mistletoe (Phoradendronjuniperinum) is a native 

plant that grows on Utah juniper (Juniperus osteosperma) 

and other gymnosperm hosts. Its range includes southern 

Nevada, southwestern Utah, southeastern California, southwestern Arizona, northern Baja California, Sonora, and 

Sinaloa (Haigh 1996; Benson and Darrow 1981). Previous 

studies of host-mistletoe relationships include Blumer 

(1910), Shreve and Wiggins (1964), Walters (1976), Daniel 

and Butterwick (1992), and Haigh (1996). Phoradendron 

villosum, a closely related species to juniper mistletoe, 

revealed a clumped dispersion pattern on several oak 

(Quercus spp.) hosts in California (Hollinger 1983). In general, juniper mistletoe shows significantly more negative 

leafwater potentials than its Utah juniper host, and infected 

host trees experience lower leaf potentials than uninfected 

trees through a growing season under a range of environmental conditions (Ehleringer and others 1986; Fisher 

1983). In the Mojave Desert, water potentials of host plants 

can become extremely negative during summer months. 

California mistletoe (Phoradendron californicum) reveals 

lower water potential values, averaging 1.4 MPa below its 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Simon A. Lei is a Biology and Ecology Professor at the Community 

College of Southern Nevada, 6375 West Charleston Boulevard, W2B, 

Las Vegas, Nevada 89102-1124. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

catclaw (Acacia greggii) and creosote bush (Larrea tridentata) hosts during the 1996 drought in the Granite Cove of 

southern California (Dean Jordan, personal communication). 

Although juniper mistletoe is not common throughout 

southern Nevada, it commonly parasitizes Utah juniper in 

Pine Creek. The objectives of this article were four-fold: 

(1) to address the spatial pattern of juniper mistletoe infection of Utah juniper trees; (2) to compare the height, vigor, 

viability, and reproductive success of the parasitized and 

unparasitized Utah juniper trees; (3) to examine the water 

relations of mistletoe and its host; and (4) to investigate 

mistletoe infection success between slightly and heavily 

parasitized trees during a severe drought in Pine Creek of 

southern Nevada. 

Methods __________ _ 

Study Area 

The field study was conducted from spring to fall of 1996 

in the Pine Creek portion of the Red Rock National Conservation Area (36°05' N, 115°40'W; elevation 1,400 m), 

located approximately 50 km west of Las Vegas, Nevada. 

Pine Creek was selected on the basis of mistletoe infection 

success and various infection stages (early, middle, and late) 

on Utah juniper trees. The vegetation is transitional between blackbrush (Coleogyne ramosissima) shrubland and 

Utah juniper woodland, with Utah juniper being considerably more abundant along an intermittent stream with 

water running only during parts of the year. This surface 

stream is often dry during the peak of summer season from 

June through August, unless it is recharged by moderate to 

heavy rainfalls. The precipitation in southern Nevada includes summer storms and winter rains, averaging 250 mm 

annually. Summer rain typically occurs in July and August, 

and can be locally intense. Winter rain is widespread and 

may last several days (Rowlands and others 1977). Much of 

the 1996 year was extremely dry with a total amount of 

precipitation falling well below the annual average. Relative 

humidity of 20 percent or less is common with high evaporation in the summer months. 

Blackbrush and Utah juniper share a relatively broad 

ecotone in southern Nevada (Lei 1994, 1995). Singleleaf 

pinyon-Utah juniper (Pinus monophylla-Juniperus osteosperma) woodland is often established on high desert mountain slopes above the blackbrush shrubland in southern 

Nevada. Utah juniper is typically more abundant at the 

lower elevations, with a homogeneous mixing of singleleaf pinyon and Utah juniper at the middle elevations of 

the pinyon-juniper vegetation zone (West and others 1975). 

99 
Dispersion of Juniper Mistletoe 

The study site covered approximately 3.5 ha., and all 85 

Utah juniper trees within this area were surveyed for the 

presence and distribution of juniper mistletoes. The evergreen j uni per mistletoe was easily visible among the bare 

and nearly bare branches of its juniper host, appearing as a 

slightly lighter green or brownish-green patch on Utah 

juniper trees. I counted and recorded the number of 

juniper mistletoes and measured the height on juniper 

trees for an analysis of the spatial dispersion pattern. The 

dimensions of juniper mistletoe were not measured, and sex 

could not be accurately determined. 

The Utah juniper trees sampled ranging in height from 

0.75 to 7 m, and included individuals without any visible 

juniper mistletoes (control) and individuals with mistletoes 

(infected trees). Within the infected trees, uninfected stems 

were segregated from infected stems. Uninfected stems did 

not show any visible mistletoes on the stem all the way back 

to the main trunk. Infected stems had mistletoes on the 

secondary branches. 

Vigor, Viability, and Reproductive 

Success of Utah Juniper 

The amount of host tree branches covered with green 

leaves was visually estimated in ten percentage point increments. The viability of parasitized and unparasitized Utah 

juniper trees was determined by coring through at least 

one-half of the stem diameter containing pith. Incremental 

cores were extracted from main trunks at 1.0 m above 

ground and from five Utah juniper individuals that were 

randomly selected in each of the three height categories 

(0-2, 2-4, and 4-7 m). The size of fruits (berry diameter) 

between parasitized and unparasitized trees was measured. 

The number offruits (berries) produced by Utahjuniperwas 

visually estimated. 

Water Potential Measurements 

A total of 20 Utah juniper trees and a juniper mistletoe 

on each parasitized (light and heavy infections) tree were 

randomly selected and tagged with yarn before water potential measurements to facilitate repeated sampling throughout the day. Five replicates were made in each of four 

treatments (mistletoe, uninfected Utah juniper, infected 

and uninfected stems on mistletoe-infected juniper tree). 

Water potentials of juniper mistletoe and its Utah juniper 

host were obtained using a portable pressure chamber and 

nitrogen gas. Once the leaves were incised, they were 

immediately placed in zip-Ioc plastic bags and housed on ice 

in the dark until pressurization, which was rapidly conducted at the field site. Water potentials were measured on 

10-15 cm long terminal leaves at predawn and then at 3-hour 

intervals throughout the day. Diurnal water potential data 

were collected twice, once in March and once in July 1996. 

Routine analysis of predawn and midday water potentials of 

mistletoes and juniper trees was conducted at 8-week 

intervals from April through October of 1996. 

100 

Statistical Analyses 

The Poisson distribution was used to determine the type 

of spatial dispersion pattern (random, uniform, or clumped) 

that populations of juniper mistletoe exhibited on Utah 

juniper. One-way analysis of variance (ANOVA) was employed to detect differences in diurnal and seasonal water 

potentials among the four treatments. Students t-tests were 

performed to compare the height, vigor, viability, and reproductive success between the parasitized and uhparasitized 

Utah juniper trees. Statistical significance was determined 

at p::; 0.05. 

Results and Discussion 

Eighty-five Utahjuniper trees were sampled in Pine Creek 

for an analysis of the spatial dispersion. The occurrence of 

juniper mistletoes was on Utah juniper trees only. Juniper 

mistletoes did not infect blackbrush or other common shrubs 

nearby, such as banana yucca (Yucca baccata), big sagebrush (Artemisia tridentata), cheesebush (Hymenoclea 

salsola), and yerba santa (Eriodictyon angustifolium), at 

the blackbrush-Utah juniper ecotone. A majority of juniper 

trees had either no juniper mistletoe growth (35.3 percent 

or 30 of 85 trees) or had more than five mistletoe individuals (48.2 percent or 41 of 85 trees; fig. 1). Only 16.5 percent 

(14 of85) of trees fell between these two classes (fig. 1). The 

distribution of individual mistletoes was clumped (p < 0.05), 

which corresponds with Hollinger'S (1983) study. Mistletoe 

fruits are fleshy, producing a single seed with sticky viscou~ 

layer (Calder and Bernhardt 1983). Mistletoe seeds tend to 

50 

U) 40 IJ.I 

IJ.I 

0::: 

I0::: 

IJ.I 30 Cl.. 

Z 

::J 

, 

u.. 

0 20 

0::: 

IJ.I 

m 

~ 

::J 10 z 

o 

NUMBER OF MISTLETOES PER JUNIPER 

Figure 1-Distribution of juniper mistletoes on 85 Utah 

juniper individuals in Pine Creek of the Red Rock Canyon 

National Conservation Area in southern Nevada. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
200 

b 

LU 

0 

~ 

LU 150 ...J 

~ 

en 

~ 

LL.. 

0 100 0:::: 

W 

[]J 

::I: 

::> 

z 

z 50 

< w 

:i 

o 

0-2 2-4 4-7 

HEIGHT OF JUNIPER TREE (m) 

Figure 2-Number of juniper mistletoe (mean ± S.E.) 

growing on Utah juniper trees with variable heights in 

Pine Creek of the Red Rock Canyon National Conservation Area in southern Nevada. Height of Utah juniper 

trees was divided into three categories: 0-2 (n = 6), 2-4 

(n = 25), and 4-7 m (n = 24). Different letters at the top of 

columns represent statistical significant at p s; 0.05. 

stick to birds, and mistletoe is usually spread from host to 

host by birds, which ingest the seeds and later defecate them 

onto a branch (Haigh 1996). Birds, including northern mockingbird (Minus polyglottos), appear to roost in specific areas 

which would clump mistletoes in these areas where they 

roost and subsequently defecate. The distribution of many 

species, including parasitic organisms, is generally contagious, but is seldom regular in nature (Postlethwait and 

Hopson 1995). 

Juniper mistletoes grew on Utah juniper trees ranging 

from a height of 0.75 to 7.0 m (fig. 2). The abundance of 

juniper mistletoe was significantly and positively correlated (p < 0.001; r = 0.81) with the heights of Utah juniper 

hosts. Juniper mistletoe was most numerous on taller host 

trees, although two of the hosts that were approximately 

6.0 m tall were not infested by mistletoes. Mistletoe-infested 

juniper trees were significantly taller (p < 0.01; table 1) than 

adjacent, uninfested trees. In general, the taller trees were 

older than the shorter trees (data not shown). Yet, the 

precise ages of host trees were difficult to determine due to 

the possibility of partial, missing, and double annual rings. 

Biseasonal rainfalls may produce double annual rings, 

while severe droughts during the growth periods may show 

a partial or missing ring within a single year . 

Various stages of juniper mistletoe infections on Utah 

juniper trees were evident in Pine Creek. The high levels of 

mistletoe infestation of greatly influenced the vigor, viability, and reproductive success of juniper trees regardless of 

their size. The amount of berry production and green leaves 

on branches in the infested juniper trees were significantly (p < 0.001; table 1) reduced. Conversely, no significant (p > 0.05; table 1) differences were detected in berry size 

(diameter) between the parasitized and unparasitizedjuniper trees, although the berry size was smaller in parasitized 

trees. Within the infected juniper trees, hosts with heavy 

infections (>25 mistletoes per tree) typically showed the 

smallest berry size, and showed the least amount of green 

leaves and berry production than juniper hosts with light 

infections. Low host vigor can lead to rapid mortality following severe drought and pest outbreak (Calder and Bernhardt 

1983). 

There are several potential explanations for the higher 

levels of juniper mistletoe infestation exhibiting a clumped 

distribution in taller and larger host trees. First, large tree 

size would provide a greater surface area (more secondary 

branches) available for mistletoe colonization. Increasing in 

tree size, along with a greater surface area, may increase the 

host susceptibility of mistletoe colonization and infestation. 

Second, many taller trees were older with a greater stem 

diameter than shorter trees. This phenomenon may indicate 

a time dependent mistletoe colonization rate. The number of 

mistletoe may increase with increasing tree age. Third, 

some birds may prefer taller and larger trees by visiting 

infested trees to feed on the mistletoe's fruits, and then 

remain on the infested trees long enough to deposit the 

seeds on the same trees. Dispersal of mistletoes may also be 

influenced by arboreal mammals and by gravity, but these 

are likely to be minor mechanisms (Calder and Bernhardt 

1983). 

Both juniper mistletoe and Utah juniper plants were 

significantly (p < 0.001; fig. 3) more water stressed in July 

than in March. Water potentials of mistletoes and itsjuniper 

hosts were significantly (p < 0.001; fig. 4) more negative 

during midday than predawn hours through the growing 

season. Conversely, no significant differences (p > 0.05; 

fig. 3 and 4) were detected in juniper leaf water potentials 

between the infected and uninfected stems on the mistletoeinfected trees in both diurnal and seasonal measurements. 

Table 1-A comparison of height, vigor, and reproductive success (berry size and production) between 

mistletoe-infested and adjacent, uninfested (control) Utah juniper trees (mean ± S.E., n = 85). The 

amount of host tree branches covered with green leaves (vigor) is expressed in percentage. Mean 

values in columns followed by different letters are significantly different at p s; 0.05. 

Tree group 

Infested tree 

Uninfested tree 

Height 

m 

4.8 ± 0.7 a 

3.2 ± 0.4 b 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Percent green leaves 

47.2 ± 19.7 a 

86.5 ± 9.8 b 

Berry diameter 

7.8 ± 0.2 a 

8.4 ± 0.1 a 

Berry number 

217.9 ± 69.2 a 

355.4 ± 50.5 b 

101 
.... :, 

0 

A. March, 1996 • Mistletoe 

.... Infected stem 

,--. • 0 Uninfected stem 0... -1 ::2 .... Control '---/ 

---1 

~ 

fz 

w 

ra -2 -~ .. 0... 

0::: 'II 

W 

f-« 

3: 

Z 

« 

w -3 :2 

J 

6 9 12 15 

HOUR OF DAY 

0 

B. July, 1996 • Mistletoe 

.... Infected stem 

,,-... • 0 Uninfected stem D- -1 

L .... Control '--"" 

~ 

« 

i= 

z 

W 

fa -2 DO::: 

W 

f-

« 

S 

z 

« 

w -3 :2 

-4 ~ ______ ~ ______ L-____ ~ ______ ~ ______ ~ 

6 9 12 

HOUR OF DAY 

Figure 3-Diurnal water potentials (mean ± S.E.) 

of juniper mistletoes, leaf tissues from infected 

stems and uninfected stems of the Utah juniper hosts, 

and from an adjacent, uninfected (control) juniper 

hosts in March (A) and July (8), 1996. Measurements 

(n = 5 per treatment in each hour) were made at 

3-hour intervals starting from early morning through 

mid-afternoon. 

102 

15 

0 

A. Predawn 

,.-., -1 0 

0... 

::2 

'-" 

~ 

« 

i= -2 z 

w 

fa 

Q.. 

0::: 

w -3 r-« • MisLletoe 5; 

'7 « .... Infected stem w 

:2 -4 • Uninfected stem 

.... Control 

-5 

APRIL JUNE AUGUST OCTOBER 

MONTH OF YEAR (1996) 

0 

B. Midday • Mistletoe 

.... Infected stem 

r--.. -1 • Uninfected stem 0 

DL .... Control ---' 

~ 

~ / 

« 

i= -2 z 

w 

fa 

DO:::: 

w -3 r-

« 

S 

z 

« 

w 

L 

-4 [_ 1 

-5 

APRIL JUNE AUGUST OCTOBER 

MONTH OF YEAR (1996) 

Figure 4-Seasonal water potentials (mean ± S.E.) 

of juniper mistletoe, leaf tissues from infected 

stems and uninfected stems of the Utah juniper 

hosts, and from an adjacent, uninfected (control) 

juniper hosts. Measurements (n = 5 per treatment 

in each month) were made during predawn (A) and 

midday (8) hours through the growing season from 

April to October, 1996. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Leaf water potentials of juniper mistletoe tissues were 

considerably more negative than Utah juniper tissues of 

either infected stems or uninfected stems (fig. 3 and 4). 

Leafwater potentials of mistletoe tissues were significantly 

(p < 0.001) lower than leaf water potentials of adjacent, 

uninfectedjuniper trees (fig. 3 and 4). Mistletoes are characterized by extremely low water use efficiencies and must 

maintain more negative water potentials than their hosts in 

order to obtain water (Dean Jordan, personal communication). My results generally concur with Ehleringer and 

others' (1986) study, indicating that mistletoe-infected trees 

consistently have leaf water potentials lower than adjacent, 

uninfected trees, and that juniper mistletoe was imposing a 

significant water stress on Utah juniper. 

Because of the higher rates of water loss associated with 

mistletoe parasitism, infected Utahjunipertrees experience 

significantly lower leafwater potentials than do uninfected 

juniper trees (Ehleringer and others 1986). In leafy mistletoes, the inability of stomata to respond to environmental 

stress may largely account for considerable water loss in 

massive infections (Fisher 1983). During stress, stomata of 

mistletoe remain open and transpiration rates of mistletoe 

remain higher than its Utah juniper host. Photosynthesis is 

curtailed in Utah juniper trees because of stomatal closure 

in response to environmental stress (Fisher 1983). Several 

aspects of Utah juniper water relations (leaf conductance, 

leaf water potential, and water use efficiency) are worsened 

by the presence of juniper mistletoe (Ehleringer and others 

1986). Host with heavy infections generally revealed lower 

leaf water potential than hosts with light infections in this 

study. Increased infestation can aggravate this water stress 

situation, but since whole plant water balances were not 

measured in this study, the magnitude of this effect on host 

productivity cannot be accurately determined (Ehleringer 

and others 1986). 

From casual observations, Utahjuniper hosts with light to 

moderate infections may benefit juniper mistletoes, as evidenced by a slightly larger berry size and by a greater foliage, 

flower, and fruit production (biomass). As infection intensifies over time, however, the mortality of established juniper 

mistletoes became evident when a portion of host tree 

branches was dead. Within a single host, the live secondary 

branches supported abundant mistletoes, while the dead 

secondary branches revealed dead mistletoes regardless of 

tree size. Hence, juniper mistletoes may not be a successful 

parasite because, after several years of colonization and 

infestation, mistletoes can kill their hosts, leading to their 

own death. 

Southern Nevada in recent years experienced severe 

droughts, resulting in widespread plant water stress and 

in an increased mortality of established juniper mistletoe 

infections. Substantial juniper mistletoe mortality on its 

Utah juniper host was observed during the 1996 drought. 

More mistletoes died from hosts with heavy infections than 

with light infections, partially due to an increase in water 

stress of host plants during the drought. Mistletoes showing heavy infections generally have leaf water potentials 

0.2-0.7 MPa lower than mistletoes showing light infections 

(data not shown), presumably due to an intense resource 

competition among mistletoe individuals. Low host-plant 

USDA Forest Service Proceedings RMRS-P-9. 1999 

water potentials with massive infections during severe 

droughts may limit long-term mistletoe infection success 

(Dean Jordan, personal communication) irrespective to host 

tree size. 

Parasitic mistletoes live in close physical association 

with host to obtain nourishment and may weaken or kill its 

host (Postlethwait and Hopson 1995). The final outcome is a 

net gain in mistletoe foliage, which occupies more and more 

of the host canopy as the infection intensifies (Fisher 1983). 

In juvenile trees, infection greatly reduces root growth and 

the ability to survive drought and insect outbreak (Fisher 

1983). All mistletoes show some degree of parasitism or 

dependence on a host plant, and all use the xylem sap of the 

host to provide water and mineral nutrients (Fisher 1983). 

In this study, mistletoes can be considered a water parasite 

because mistletoe-infectedj uniper trees, irrespective to their 

size, consistently exhibited greater water stress (lower water potentials) than adjacent, un infected trees. 

Conclusions _________ _ 

Results of this study indicated that many Utah juniper 

individuals exhibited no or severe infestation by parasitic 

juniper mistletoes, and that populations of juniper mistletoes revealed a clumped dispersion pattern among Utah 

juniper trees. Taller juniper trees were significantly more 

likely to be parasitized than shorter trees. The higher 

colonization rate and infection level of mistletoes in taller 

and larger host trees appeared to be a combination of tree 

size, age, and seed dispersal by some bird species. Heavy 

mistletoe infestation severely limited host's vigor, viability, 

and reproductive success regardless of host size. Juniper 

mistletoes are not likely to be a successful parasite since 

heavy infestation during the severe 1996 drought would 

lower their host-plant water potentials, which might limit 

mistletoe's long-term infection success. Trees without juniper mistletoes were significantly less water stressed than 

trees with mistletoes. However, no significant differences 

were detected between the infected and uninfected stems of 

mistletoe-infected Utah juniper trees. 

Acknowledgments 

I gratefully acknowledge the valuable field work conducted 

by Steven Lei, David Valenzuela, and Shevaum Valenzuela. 

David Charlet and Leslie Thomas provided critical review of 

this manuscript. 

References ________________ _ 

Analytical Software. 1994. Statistix 4.1, an interactive statistical 

program for microcomputers. Analytica Software, Tallahassee, 

Florida. 329 p. 

Benson, L. and R. A. Darrow. 1981. Trees and shrubs of the 

southwestern deserts. Univ. of Arizona Press, Tucson, Arizona. 

416 p. 

Blumer, J. C. 1910. Mistletoe in the Southwest. Plant World. 13: 

240-246. 

Fisher, J. T. 1983. Water relations of mistletoes and their hosts. In: 

Calder, M. and P. Bernhardt, editors. The Biology of Mistletoes. 

Academic Press, New York: 146-184. 

103 
Ehleringer, J. R, C. S. Cook, and L. L. Tieszen. 1986. Comparative 

water use and nitrogen relationships in a mistletoe and its host. 

Oecologia. 68: 279-284. 

Haigh, S. L. 1996. Saltcedar (Tamarix ramosissima), an uncommon 

host for desert mistletoe (Phoradendron californicum). Great 

Basin Naturalist. 56: 186-187. 

Hollinger, D. Y. 1983. Photosynthesis and water relations of the 

mistletoe, Phoradendron villosum, and its host, the California 

valley oak, Quercus lobata. Oecologia. 60: 396-400. 

Lei, S. A. 1994. Plants of the North American Deserts. Unpublished 

research report, Univ. of Nevada, Las Vegas, Nevada. 64 p. 

Lei, S. A. 1995. A gradient analysis of Coleogyne communities in 

southern Nevada. Unpublished masters thesis, Univ. of Nevada, 

Las Vegas, Nevada. 117 p. 

Odum, E. P. 1971. Fundamentals of Ecology. W.B. Sanders Company, New York, New York. 574 p. 

104 

Postlethwait, J. H. and J. L. Hopson. 1995. The Nature of Life. 

McGraw-Hill, Inc., New York, New York. 406 p. 

Rowlands, P. G., H. Johnson, E. Ritter, and A. Endo. 1977. The 

Mojave Desert. In: M. Barbour and J. Major, editors, Terrestrial Vegetation of California. John Wiley and Sons, New York, 

New York. 1002 p. 

Shreve, F. and 1. L. Wiggins. 1964. Vegetation and flora of the 

Sonoran Desert. Volume 1. Standford Univ. Press, Palo Alto, 

California. 840 p. 

Walters, J. W. 1976. A guide to mistletoes of Arizona and New 

Mexico. USDA Forest. Service, Southwestern Region, Forest 

Insect and Disease Management. 7 p. . 

West, N. E., K. H. Rea, and R J. Tausch. 1975. Basic synecological 

relationships in pinyon-juniper woodlands. The pinyon-juniper 

ecosystems: a symposium, p. 41-52. Utah State Univ., Logan, 

Utah. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Utah Juniper Herbaceous Understory 

Distribution Patterns in Response to Tree 

Canopy and Litter Removal 

Chad S. Horman 

Val Jo Anderson 

Ahstract-A 3-year field study was conducted to determine the 

effects of Utah juniper (Juniperus osteosperma) canopy and litter 

removal on native and seeded plant distribution patterns. Two 

zones were identified surrounding Utah juniper, one beneath the 

canopy and the second in the interspace. Plant abundance and 

seedling emergence were higher in the canopy zone. Canopy removal caused a decrease in plant abundance and seedling emergence in the canopy zone and had no effect in the interspace. Litter 

removal had almost no effect on plant abundance, except for annual 

forb abundance, which increased following litter removal. Effect 

of litter removal on seeded species was species dependent. 

The pinyon-juniper woodland is an important ecosystem 

of the western United States, comprising of approximately 

60 million acres throughout Nevada, Utah, Colorado, New 

Mexico and Arizona, with two leaf pinyon pine (Pinus edulis) 

as the principal pine species. Common juniper species include Utah juniper (Juniperus osteosperma), alligator juniper(Juniperusdeppeana),oneseedjuniper(Juniperusmonosperma) and Rocky Mountainjuniper(Juniperus scopulorum) 

(Hurst 1987). In pre-settlement days, juniper was most 

abundant in southwestern U.s., but distinct populations 

could be found on rocky mid-elevation foothills of the Great 

Basin. Since the mid 1800's juniper has slowly encroached 

into the valleys of the Great Basin. As juniper has become 

the dominant species in these communities, elements of both 

the biotic and abiotic environments have been modified 

(Tausch and others 1981). This has been a serious problem 

for land managers, because as these trees come to dominance on a site the herbaceous understory is severely reduced (Dye and others 1995; Schott and Pieper 1985; Young 

and Evans 1981; Barney and Frischknecht 1974; Clary 

1971). Increased precipitation runoff and soil erosion has 

been reported as a result of this community shift (Farmer 

1995). Many ideas have been forwarded to explain the recent 

juniper invasion. The most commonly stated ideas are 

(1) lack of periodic fires which would normally kill many 

young trees (Hurst 1987; Young and Evans 1981; Burkhardt 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Chad S. Horman is a Restoration Ecologist, Environmental Science and 

Research Foundation, Inc., P.O. Box 51838, Idaho Falls, ID 83405-1838. Val 

Jo Anderson is an Associate Professor of Range Science, Department of 

Botany and Range Science, Brigham Young University, 493 WIDB, P.O. Box 

25228, Provo, UT 84602-5228. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

and Tisdale 1976), (2) spreading of seed by livestock 

(Burkhardt and Tisdale 1976), (3) overgrazing by livestock, 

which reduces grass competition with juniper seedlings 

(Hurst 1987) and (4) a climatic shift that favors woody 

species (Johnsen 1962). These postulates suggest explanations as to why junipers are able to establish themselves, but 

not how they are able to maintain dominance on a site. 

Junipers may be able to dominate a site and maintain that 

dominance by way of (1) increased canopy cover which 

creates shading and precipitation interception (Schott and 

Pieper 1985; Anderson and others 1969; Skau 1964; Johnsen 

1962), (2) deep litter accumulation (Horman and Anderson 

1996; Schott and Pieper 1985; Everett and Koniak 1981; 

Jameson 1966; Johnsen 1962), (3) allelopathy (Peterson 

1972; Jameson 1970a; Jameson 1961), (4) changes in the soil 

nutrient composition (Doescher and others 1987; Klopatek 

1987; Brotherson and Osayande 1980) and (5) competition 

for soil moisture (Evans and Young 1985; Young and Evans 

1981' Jameson 1970b; Johnsen 1962). 

It has been shown that the canopy of one seed juniper 

(Armentrout and Pieper 1988; Schott and Pieper 1985; 

Arnold 1964), redberry juniper (Juniperus pinchotii) (Dye 

and others 1995; McPherson and others 1991), eastern red 

cedar (Juniperus virginiana) (Engle and others 1987), westernjuniper(Juniperusoccidentalis) (Vaitkus and Eddleman 

1991) and Utah juniper (Everett and Koniak 1981; Barney 

and Frischknecht 1974; Clary 1971) all affect understory 

distribution. These negative effects have been attributed to 

shading, rainfall interception or litter accumulation. Schott 

and Pieper (1985) determined that in younger stands of one 

seedj uni per, shading, ca used by the characteristically dense, 

low hanging canopy, was the leading cause oflow understory 

production. Anderson and others (1969) stated that understory vegetation is more responsive to differences in 

throughfall precipitation than differences in light. Juniper 

canopy is reported to intercept about 10-20 percent of 

precipitation (Skau 1964). This amount of interception may 

explain why some species can not survive. 

Litter accumulation has been studied as a deterrent of 

understory growth either due to its depth (Horman and 

Anderson 1996; Everett and Koniak 1981; Jameson 1966; 

Johnsen 1962) or to allelopathic properties (Peterson 1972; 

Jameson 1970a; Jameson 1961). Jameson (1966) stated that 

litter accumulation from one seed juniper was more detrimental than shading in the mature stand that he studied. He 

found that blue grama (Bouteloua gracilis) basal area and 

production were not affected by the roughly 40 perce?t 

shading, but that litter accumulation did adversely affect It. 

Horman and Anderson (1996) reported that while not affected by allelochemic properties, antelope bitterbrush 

105 
(Purshia tridentata) and bluebunch wheatgrass (Pseudoroegnaria spicata) emergence were negatively affected by 

increasing Utah juniper litter depth. 

Litter not only affects plant emergence but also plant 

distribution. Everett and Koniak (1981) reported three litter 

zones under Utah juniper canopies in Nevada. The first was 

closest to the trunk and constituted litter cover >90 percent 

at a depth >0.5 cm. This zone had practically no vegetation. 

The second was under the majority of the canopy and had 

litter cover of20-90 percentatadepth>0.5cm. This zone had 

increasing amounts of vegetation. The last was near the 

canopy edge and contained the most vegetation. It consisted 

oflitter cover <20 percent at a depth of <0.5 cm. They agreed 

with Jameson (1966) that litter depth was the leading 

deterrent of understory growth. This zonation pattern was 

similar to that found by Armentrout and Pieper (1988) 

around one seed juniper trees. They reported an increase in 

basal cover on understory vegetation from <1 percent near 

the trunk to 7 percent under the canopy and finally 12 percent 

in the interspace. 

Juniper trees are also competitive due to their shallow 

root zones that extend out a distance that is two or three 

times the tree height for some species (Johnsen 1962). This 

allows the juniper to compete very effectively for any available moisture (Young and Evans 1981; Jameson 1970b; 

Johnsen 1962). It has also been suggested that junipers may 

have phytotoxic root exudates (Jameson 1970b). 

The majority of juniper literature has focused on juniper 

species other than Utah juniper and little has been done in 

the foothill environment of central Utah. A field study was 

conducted in a foothill Utahjuniper woodland community in 

central Utah that focused on the influence of Utah juniper 

canopy on the understory and interspace vegetation. The 

effects ofU tahj uni per canopy on six seeded species were also 

tested. The objectives of this study were to determine the 

effect of Utah juniper canopy removal and litter removal on 

the native plant community as well as some commonly 

seeded species. 

Study Site and Methodology 

The study site was located in a pinyon-juniper woodland 

between Water Hollow and Tie Fork Canyon in Spanish 

Fork Canyon, Utah Co., UT. Three sites with southern 

exposure, located at least 1.5 km apart, were chosen in this 

area. At each site, 10 mature juniper trees were selected that 

had a minimum of one meter of canopy interspace at least 

halfway around it. Underneath each tree, four vegetational 

transect lines were placed with equal spacing between them. 

The lines ran from the trunk to the canopy edge and out into 

the middle of the tree interspace (not to exceed 3 m). Along 

each transect, three zones were identified. The trunk zone 

extended from the trunk to mid point of the canopy radius. 

The mid canopy zone extended from the mid point of canopy 

radius to the dripline (dripline was defined as the furthest 

reaching branch over the transect). The interspace zone, 

consisted of the area that extended beyond the drip line 

(Armentrout and Pieper 1988). 

A 25 x 50 cm quadrat, using a modified Daubenmier 

method of seven cover classes (Daubenmier 1959), was 

placed contiguously along each line. At each placement, 

percent cover was recorded for total vegetation, perennial 

106 

grass, annual grass, perennial forb, annual forb, shrub, 

litter, rock, bare ground and cryptograms. Nested frequency 

values were also recorded for total vegetation, perennial 

grass, annual grass, perennial forb, annual forb and shrub. 

Litter depth was also measured in the center of each quadrat. Finally, at each site, three 61 m line intercept transect 

were evaluated to determine canopy overstory cover. 

Following the baseline vegeta tion inventory (August 1995), 

five of the ten trees at each site were randomly selected, cut 

down, and removed from the site with as little disturbance 

to the ground cover as possible. At the same time, the litter 

was removed from half of the area underneath both intact 

and removed trees. This created four treatments; (1) tree 

canopy with intact litter (control), (2) tree canopy with litter 

removal, (3) tree removal with intact litter and (4) tree 

removal with litter removal. 

Following tree and litter removal, six species were planted 

in the fall of 1995. The species used were bluebunch wheatgrass (Pseudoroegnaria spicata (Pursh) Love 'Secar'), bottlebrush squirreltail (Elymus elymoides (Raf.) Swezey), orchardgrass (Dactylis glomerata L. 'Pia ute'), Lewis flax (Linum 

lewisii Pursh 'Appar'), small burnet (Sanguisorba minor 

Scop. 'Delar') and antelope bitterbrush. All six species were 

planted on the half with intact litter and all six on the half 

without litter. Each halfwas divided into six equal areas and 

each area was broadcast seeded with one ofthe six species at 

a rate of 10 lb./acre pure live seed, except for antelope 

bitterbrush. It was planted in five caches of five seeds at 

equal distances (Vander Wall 1994). Seedling density was 

monitored for two years (summers of 1996 and 1997). 

Experimental design consisted of a split-split plot design, 

with site being the main effect, tree and litter treatments as 

subplots and zone pattern as sub-subplot. Percent cover and 

recruitment data were arcsine transformed prior to analysis. ANOVA was performed using the Statistical Analysis 

System (SAS) computer program and a Fisher's protected 

LSD was used for mean separation (Ott 1993). Differences 

were deemed significant when P < 0.05 unless otherwise 

indicated. 

Results __________ _ 

The study area had a combined Utah juniper and pinyon 

pine overstory cover of31.9 percent. Utah juniper cover was 

20.5 percent and pinyon pine cover was 11.4 percent. Average understory vegetation and cryptogram cover throughout the area were both very low at 8 percent and 1.5 percent, 

respectively. The understory composition consisted of 44.2 

percent perennial grass, 1.8 percent annual grass, 31.2 

percent perennial forb, 12.3 percent annual forb and 10.6 

percent shrub. Litter cover was the highest at 61 percent. 

Bare ground and rock were 24.8 percent and 4.5 percent, 

respectively. 

Significant differences were found among the three zones 

with respect to litter depth. The trunk, mid canopy and 

interspace zones had mean ± SD litter depths of5.1 ± 2.5 cm, 

1.0 ± 0.8 cm and 0.1 ± .08 cm, respectively. Three distinct 

zones were also found with respect to litter cover. Litter 

cover decreased significantly from 89 percent in the trunk 

zone to 76 percent in the mid canopy zone and finally to 

26.6 percent in the interspace. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Vegetative cover was very low throughout the study and 

was not sensitive to the treatments or zone patterns. The 

observed differences due to zone and treatments were negligible, in many cases less then 1 percent. These differences 

were deemed insignificant from both a biological and land 

management stand point and were therefore not reported in 

this study. Nested frequency, by design, was more sensitive 

to the abundance of rare species and was useful in determining treatment effects. 

Nested frequency values were recorded from 0 to 5 with 5 

indicating the highest abundance. Zonation patterns were 

apparent around juniper trees (table 1). In some cases these 

patterns were influenced by whether or not tree or litter 

removal occurred. A significant (P = 0.06) tree by zone interaction was found with respect to total vegetation abundance 

(fig. 1). Abundance was higher beneath the canopy than in 

the interspace around living trees. On sites where tree 

removal occurred, total vegetation abundance did not differ 

among the three zones. Abundance of perennial and annual 

grasses were found to be significantly higher beneath the 

canopy compared to the interspace. A significant tree by 

zone interaction (P = 0.04) (fig. 2) and litter by zone interaction (P = 0.005) (fig. 3) occurred with respect to annual forb 

abundance. On the tree control sites, annual forb abundance 

was higher beneath the canopy than in the interspace. 

However, on the sites where juniper removal occurred, 

annual forb abundance was similar among all three zones. 

The litter by zone interaction indicated that annual forb 

abundance was similar among the three zones where the 

litter was left intact. Following litter removal, annual forb 

abundance increased in the trunk and mid canopy zones and 

decreased in the interspace. Perennial forb and shrub abundance did not differ among the three zones. 

Tree removal had differing effects on plant abundance 

(table 2). The tree by zone interactions of total vegetation 

and annual forb abundance indicated that abundance in the 

canopy zones decreased sharply following tree removal, 

while abundance in the interspace showed a slight decline or 

remained unchanged. Perennial grass and forb abundance 

significantly decreased following tree removal , while annual 

grass and shrub abundance remained unchanged. 

Litter removal had a limited effect on plant abundance 

(table 2). Abundance of total vegetation, annual grasses, 

perennial forbs and shrubs were not affected by litter removal. Perennial grass abundance significantly decreased 

where litter removal occurred. As mentioned above, a litter 

Table 1-Nested frequency values for vegetation groups according to three zones surrounding 

individual Utah juniper trees in Spanish Fork Canyon, UT. 

Total Perennial Annual Perennial Annual 

Zone vegetation grass grass forb forb Shrub 

Trunk SI 0.8 a* 0.2 a 0.7 a SI 0.1 a 

Mid canopy SI 0.9 a 0.2 a 0.9 b SI 0.4 a 

Interspace SI 0.5 b 0.1 b 0.7 a SI 0.2 a 

* Values in columns followed by a different letter were significantly different at P < 0.05 using a protected Fisher's LSD. 

SI = A significant interaction occurred with either tree removal or litter removal, main effects not shown. 

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1 

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~ •. £t. 

\' 

\\ 

-1 c;. \'. 

\\ 1.3 ...... 

'~ ~:~ Control Remove 

Tree Treatment 

Figure 1-lnfluence (P = 0.06) of Utah juniper 

canopy removal and zonation patterns on 

total vegetation nested frequency values 

(0-5) collected in a pinyon-juniper woodland 

in Spanish Fork Canyon, UT, 

Zone 

~ 

Trunk 

--9-

Mid Canopy 

• Interspace 

USDA Forest Service Proceedings RMRS-P-9. 1999 

0.6 ('\~ 

~ Q) 

:J 0.5 

~ 

~ 0.4 c: 

'" , 

O.~ 

Q) 

:J 

C" 

~ 0.3 

u.. 

'0 

Q) 

- 0.2 (J) 

Q) 

z 0.2 

0.1 0.1 ------ -----·~B.4-

Control Cut 

Tree Treatment 

Figure 2-lnfluence (P = 0.04) of Utah juniper 

canopy removal and zonation patterns on annual forb nested frequency values (0-5) collected in a pinyon-juniper woodland in Spanish 

Fork Canyon, UT. 

--- Trunk 

-..,-

Zone 

Mid Canopy 

• Interspace 

107 
0.6 u.o 

Q) 0.5 :J 

ro 

> 

>. 0.4 u 

c: 

Q) 

:J 0.3 C" 

~ u. 0.2 "C 

Q) 

en 0.1 Q) 

z 

./ • u . .) 

1"\ ,.,: / ~.v:,~ / 

'/ 

1j(U.-r 

.. U.-I 

o 

Control Remove 

Litter Treatment 

Figure 3-lnfluence (P = 0.005) of Utah juniper 

litter removal and zonation patterns on annual 

forb nested frequency values (0-5) collected in 

a pinyon-juniper woodland in Spanish Fork 

Canyon, UT. 

Zone 

... 

Trunk 

-.- Mid Canopy 

• Interspace 

Table 2-Nested frequency results for five vegetation groups in response 

to Utah juniper canopy and litter removal from three sites in 

Spanish Fork Canyon, UT. 

Tree treatment Litter treatment 

Groups Control Removal Control Removal 

Total vegetation SI SI 2.1 a* 1.3 a 

Perennial grass 0.8 a 0.6 b 0.8 a 0.6 b 

Annual grass 0.2 a 0.2 a 0.2 a 0.1 a 

Perennial forb 0.9 a 0.6 b 0.8 a 0.8 a 

Annual forb 0.9 a 0.6 b 0.8 a 0.8 a 

Shrub 0.2 a 0.3a 0.2 a 0.3 a 

"Treatment values in rows followed by a different letter were significantly 

different at P < 0,05 using a protected Fisher's LSD. 

SI = A significant interaction occurred with zone pattern, main effects not 

shown. 

Table 3-Percent recruitment of seeded species according to three 

zones surrounding individual Utah juniper trees in Spanish 

Fork Canyon, UT. 

Zone 

Species Trunk Mid canopy Interspace 

- - - - - - - - - Percent -----------

Bluebunch wheatgrass SI SI SI 

Orchardgrass 0.4 a* 0.2 a 0.0 a 

Bottlebrush squirreltail SI SI SI 

Lewis flax SI SI SI 

Small burnet 0.0 a 0.0 a 0.0 a 

Antelope bitterbrush 1.2 a 4.6 b 6.3 b 

" Values in rows followed by a different letter were significantly different at 

P < 0.05 using a protected Fisher's LSD. 

SI = A significant interaction occurred with either tree removal or litter removal, 

main effects not shown. 

108 

by zone interaction occurred with respect to annual forb 

abundance. Litter removal led to an increase in abundance 

in the trunk and mid canopy areas. 

As with plant abundance~ zonation patterns were found 

around juniper trees with respect to seedling recruitment 

(table 3). In some cases these patterns were again influenced 

by whether or not tree or litter removal occurred. Recruitment patterns of blue bunch wheatgrass and Lewis flax both 

exhibited similar interactions (P = 0.02 and P = 0.003, 

respectively) between zone and tree removal (fig. 4, 5). 

Underneath intact tree canopies, recruitment was higher in 

the trunk and mid canopy zones than in the interspace zone . 

In the tree removal areas, there was no difference among any 

of the zones. 

1. 0.9 

0.8 

-

"#. 

- 0.6 C 

(1) 

E 

.-t= 0.4 :J 

~ 

0 

\ 

\ 

\ 

\ 

"',.0.4 \ " '\ 

(1) 

0:: 0.2 

, '\ 

'" \ n 1 

0 0,0 ", §:§ 

Control Remove 

Tree Treatment 

Figure 4-lnfluence (P = 0.02) of Utah juniper 

canopy removal and zonation patterns on 

bluebunch wheatgrass seedling recruitment 

(percent) seeded in a pinyon-juniper woodland 

in Spanish Fork Canyon, UT. 

0.8 

-

~ 0.6 C 

Q) 

E 

+J 

'5 0.4 ~ 

0 

(1) 

0:: 

0.2 

I~ u.~ 

\ 

\ 

\ 

\ 

- - \ --~ . .) 

-. \ -- , \ .... 

0 n() 

"" I I M:~ 

Control Remove 

Tree Treatment 

Figure 5-lnfluence (P = 0.003) of Utah juniper 

canopy removal and zonation patterns on Lewis 

flax seedling recruitment (percent) seeded in a 

pinyon-juniper woodland in Spanish Fork Canyon, UT. 

Zone 

... 

Trunk 

-,,-

Mid Canopy 

Interspace • 

Zone 

.... 

Trunk 

-. Mid Canopy 

• Interspace 

USDA Forest Service Proceedings RMRS-P-9. 1999 
A significant litter by zone interaction (P = 0.02) was found 

with respect to bottlebrush squirreltail recruitment (fig. 6). 

On areas with intact litter, seedling recruitment decreased 

with distance from the trunk. However, on areas where the 

litter was removed no difference was found among the three 

zones. 

Antelope bitterbrush recruitment in the trunk zone was 

significantly lower than in the mid canopy and interspace 

zones (table 3). Orchardgrass and small burnet recruitment 

patterns were not apparent due to the lack of recruitment 

that occurred. 

Tree removal had a more pronounced effect on seedling 

recruitment than it did on native vegetation abundance 

(table 4). Seedling recruitment of bluebunch wheatgrass, 

bottlebrush squirreltail, Lewis flax and antelope bitterbrush were all lower where tree removal occurred. In the 

case of blue bunch wheatgrass and Lewis flax, tree removal 

only caused a significant reduction in the area beneath the 

canopy. Recruitment values in the interspace were not 

different between control and tree removal areas. The effects 

2.5 

,. ..... 

2 ..-

'(fl. 

"-

1.5 ..... 

c: 

Q) 

E 

..... 1 ':; 

~ 

(.) 

Q) 

a:: 

0.5 

\."" 

~ 

~ 

\ 

,.0.2 \ 

\. l~ U.I 

...... ,,~ 

0 4 ·0.1 v .... 

Control Remove 

Litter Treatment 

Figure 6-lnfluence (P = 0.02) of Utah juniper 

litter removal and zonation patterns on bottlebrush squirreltail seedling recruitment (percent) 

seeded in a pinyon-juniper woodland in 

Spanish Fork Canyon, UT. 

~ 

Trunk 

-yZone 

Mid Canopy 

• Interspace 

of tree removal on orchardgrass and small burnet were inconclusive due to the lack of recruitment on both treatments. 

Litter removal did not have a very strong effect on seedling 

recruitment (table 4). Bottlebrush squirreltail was the only 

species that demonstrated any response to litter removal 

(fig. 6). This response was limited to area beneath the tree 

canopy. Canopy areas with litter had higher recruitment 

than did canopy areas without litter. 

Discussion --------------------------------- Zonation patterns around juniper trees have been reported by several authors. Armentrout and Pieper (1988) 

reported three zones around one seed juniper in Arizona. 

They found a steady increase in basal vegetative cover 

occurred as one moved out from the trunk into the interspace. Dye and others (1995) also reported three vegetation 

zones around redberry juniper trees. They found that vegetative basal cover increased with distance from the trunk. 

Everett and Koniak (1981) reported opposite findings in the 

Utah juniper stands that they studied in Nevada. They 

found that the trunk and mid canopy areas produced more 

cover than did the interspace, with the mid canopy zone 

being the most productive. 

The findings of this study tend to support those of Everett 

and Koniak (1981). Zonation patterns were apparent in this 

area based on plant abundance, litter depth and litter cover. 

Significant decreases in litter depth and cover from the 

trunk out to the interspace supported the hypothesis ofthree 

zones around an individual tree (Dye and others 1995; 

Armentrout and Pieper 1988; Everett and Koniak 1981). 

Plant abundance results differed, because two zones were 

identified instead of the expected three. In most cases, the 

trunk and mid canopy areas formed one zone and the 

interspace formed the second. Greater vegetation abundance was found beneath the canopy than in the interspace. 

Total vegetation abundance was significantly different 

between the tree canopy area and the interspace, even 

though among the separate vegetation classes such patterns 

were not consistent. Among the five vegetation grou ps abundance was consistently lower in the interspace compared to 

the canopy areas, although the differences were not always 

significant. 

Table 4-Percent recruitment of seeded species in response to Utah juniper canopy and 

litter removal from three sites in Spanish Fork Canyon, UT. 

Tree treatment Litter treatment 

Groups Control Removal Control Removal 

Bluebunch wheatgrass SI SI 0.2 a* 0.1 a 

Orchardgrass 0.0 a 0.0 a 0.0 a 0.0 a 

Bottlebrush squirreltail 0.9 a 0.3 b SI SI 

Lewis flax SI SI 0.1 a 0.1 a 

Small burnet 0.0 a 0.0 a 0.0 a 0.0 a 

Antelope bitterbrush 7.5 a 1.2 b 4.3a 3.1 a 

• Treatment values in rows followed by a different letter were significantly different at P < 0.05 using 

a protected Fisher's LSD. 

SI = A significant interaction occurred with zone pattern, main effects not shown. 

USDA Forest Service Proceedings RMRS-P-9. 1999 109 
Seeding recruitment was extremely low and from a practical standpoint probably of little value. Nevertheless, the 

response to the treatments were significant in some cases. 

These results can be seen as possible indications of what may 

happen under more favorable circumstances. There were 

two potential causes for the low seeding response. The first 

was that the spring and summer of 1996 (growing season 

following the fall seeding) were unusually dry (11 ± 3.9 cm of 

summer precipitation was recorded in the area). This was 

about 40 percent of the 5 year average of 17.6 ± 4.6 cm. The 

drought that year not only affected the seeding response, but 

probably also negatively affected the existing native vegetation. The second potential cause for low response was likely 

poor seed to soil contact because the seed was broadcast and 

not covered. The reason for not artificially covering the seed 

was to attempt to simulate what might happen as a result of 

natural seed dispersal. Unfortunately, this choice resulted 

in three potential problems. The first being that adequate 

seed to soil contact probably did not occur. Even ifit did, the 

seed was on the surface and thus subject to the greater 

temperature and soil moisture fluctuations which can lead 

to lower germination (Wilson and others 1970). The second 

problem with not covering the seed was that it left them 

exposed to movement by the wind. The final problem was 

that of seed predation due to insects, birds and mammals 

(Clements and Young 1996; Vander Wall 1994). All of these 

factors probably contributed to the very low recruitment. 

Zonation patterns of the seeded species were apparent. 

Three ofthe six species, bluebunch wheatgrass, bottlebrush 

squirreltail and Lewis flax, exhibited decreasing emergence 

with increasing distance from the trunk. Bluebunch wheatgrass and bottlebrush squirreltail both demonstrated the 

two zone pattern, consisting of tree canopy and interspace. 

Lewis flax emergence showed three zones instead of two, 

with highest emergence in the trunk zone, followed by mid 

canopy and then the interspace. Antelope bitterbrush demonstrated an opposite trend with higher germination in the 

mid canopy and interspace than near the trunk. No differences were found among zon~s for orchardgrass or small 

burnet. This was most likely again due to the lack of recruitment that occurred for these two species. 

The findings of this study were contrary to those of a 

majority of studies that have reported on the effects of 

juniper on understory communities (Dye and others 1995; 

Schott and Pieper 1985; Young and Evans 1981; Clary 1971). 

The differences observed in this study as compared to previous ones may be due to differences among various juniper 

species or differences in local environments (locales other 

than foothills of central Utah). 

In this study, it appeared Utah juniper had a positive 

effect on vegetation beneath the canopy and little influence 

on the interspace vegetation. Similar findings were also 

reported by Everett and Koniak (1981) on Utah juniper 

stands in Nevada and by Vaitkus and Eddleman (1991) in 

western juniper stands. 

Work done by Jackson and Caldwell (1993) with spatial 

patterns around bluebunch wheatgrass and mountain big 

sagebrush (Artemisia tridentata var. vaseyana) indicated 

that "islands offertility" often occur around perennial plants. 

These islands are created due to increased amounts of 

organic ma tter and nutrients that occur near the plant while 

110 

the interspace is left essentially barren. On the scale of an 

individual Utahjunipertree, in this area, it would seem that 

such islands occur, due to increased plant abundance and 

seedling recruitment beneath the canopy compared to the 

interspace. 

The interspace, around these "islands", appeared to be a 

more hostile environment. Several things can occur in the 

interspace to make it a harsh environment. One such possibility, that has been forwarded by several researchers, is 

that competition for water and nutrients can occur in the 

interspace. Arnold (1964) believed that the low production in 

the interspace around one seed juniper was due to competition for water. This competition can occur due to the extensive lateral roots of juniper trees, which have been found to 

extend out two or three times the height ofthe tree (Johnsen 

1962). Young and Evans (1981) working with westernjuniper reported that even though the aerial canopy was not 

closed, excavation of the interspace revealed that it was full 

of juniper roots which in their opinion " ... effectively closed 

the stand." Johnsen (1962) reported similar findings around 

one seed junipers in Arizona. He found that lateral roots 

occupied much ofthe interspace soil. He also reported one of 

the highest concentrations of rootlets to be at the ends of the 

lateral roots in the interspace. Further evidence of this 

competition was reported by Evans and Young (1985). They 

found an increase in available soil moisture following control 

of western juniper. 

Another important factor is the difference in temperature 

and humidity between the canopy and the interspace. Johnsen 

(1962) reported that both diurnal temperature and relative 

humidity fluctuations were higher in the interspace than 

beneath the canopy. Burkhardt and Tisdale (1976) reported 

that average soil surface temperatures beneath western 

juniper reached 26° C while average soil surface temperatures in direct sunlight in the interspace averaged 60° C. 

Another difference that has been reported between the 

canopy and the interspace is that of water infiltration, soil 

nitrogen (N) content. Klopatek (1987) determined that soils 

beneath Utahjuniper in Arizona had a coarser texture, better 

water retention and more available nutrients than did interspace soils. It has been reported that N, organic matter, Ca 

and K are all higher under the canopy than in the interspace 

(Doescher and others 1987; Brotherson and Osayande 1980). 

Thus, competition for moisture and nutrients, more extreme 

temperature and relative humidity fluctuations, differences 

in soil moisture retention and soil nutrients all combine to 

create a less hospitable environment for plant growth in the 

interspace as compared to the canopy. 

Of the above possibilities, it is most likely that the effect 

of extreme temperature and soil moisture fluctuations were 

the reasons for low plant response in the interspace in this 

area. Higher plant abundance and seedling recruitment 

beneath the canopy may have been due to less extreme 

fluctuations there than in the interspace. The observed 

effects oftree removal tend to support this. Plant abundance 

and seedling emergence in the canopy area generally decreased to levels similar to that of the interspace following 

tree removal, indicating that when the canopy is removed, 

the understory area is subjected to the same extreme fluctuations in temperature and soil moisture that characterize 

the interspace zone. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Juniper litter accumulations beneath the canopy have 

been found to deter emergence of understory vegetation. 

Horman and Anderson (1996) reported that antelope bitterbrush and bluebunch wheatgrass emergence decreased as 

Utah juniper litter depth increased. Likewise, Jameson 

(1966), working with Utah juniper, and Johnsen (1962), 

working with one seed juniper, both reported that juniper 

litter reduced emergence of blue grama. It was expected 

that following litter removal that plant abundance and 

seedling recruitment would increase. As seen in the results, 

the response was somewhat mixed. Overall, there was little 

response to litter removal. Annual forb was the only exception to the generally low response. Annual forb abundance 

did show a significant increase in the canopy areas following 

litter removal, indicating that deep litter accumulations 

may inhibit growth of some species beneath Utah juniper. 

The low response, particularly the decrease in perennial 

grass abundance, was probably due to the actual process of 

litter removal. During the raking to remove the litter enough 

perennial grasses may have been inadvertently removed. 

Koniak and Everett (1983) observed that the area underneath the canopy can act as a seed trap and was an important source of seed reserves. Even though a more favorable 

microsite had been developed with the litter removal there 

simply may have been no seeds to adequately exploit it. 

Seedling recruitment either showed no response to litter 

removal, as was the case for bluebunch wheatgrass, or a 

decrease in recruitment as did bottlebrush squirreltail, 

Lewis flax and antelope bitterbrush. This agrees with the 

results of Evans and Young (1970) and Young and Evans 

(1977). Evans and Young (1970) found that some species, 

such as cheatgrass (Bromus tectorum) and medusahead 

(Taeniantherum asperum), had higher emergence under 

litter than on bare ground. Young and Evans (1977) reported 

that bottlebrush squirreltail emergence was poor on sites 

where it was not covered whether by litter or bare soil. Litter 

can act as a mulch which reduces temperature and moisture 

fluctuations (Evans and Young 1970). It appeared that in 

this study litter was ofbenefi~ to some ofthe seeded species. 

Conclusions ------------------------------- This study classified two zonation patterns associated 

with Utah juniper in central Utah, namely a canopy and 

interspace zone. Total vegetation, perennial and annual 

grasses and annual forb all had greater plant abundance 

beneath the tree canopy than in the interspace. Perennial 

forb and shrub abundance did not vary among zones. 

Several of the seeded species exhibited higher emergence 

beneath the canopy than in the interspace, these included 

bluebunch wheatgrass, bottlebrush squirreltail and Lewis 

flax. Antelope bitterbrush response differed in that higher 

emergence was observed in the interspace and canopy edge 

than near the trunk. Tree removal had no effect on annual 

grass and shrub abundance. Tree removal did affect abundance of total vegetation and perennial grass, perennial and 

annual forbs, along with seedling recruitment. These effects 

were tied closely to changes in zonation patterns. Following 

tree removal, total vegetation and annual forb abundance 

and seedling recruitment beneath the canopy decreased to 

levels found in the interspace, leading to the idea that 

USDA Forest Service Proceedings RMRS-P-9. 1999 

canopy cover was of benefit to the understory vegetation. 

When the canopy was removed, the area was exposed to 

greater fluctuations in temperature and soil moisture than 

when the canopy was present. 

Litter removal had a limited effect on plant abundance. 

Nested frequency values indicated that annual forb abundance increased with litter removal while perennial grass 

abundance decreased. Litter removal findings were somewhat inconclusive because ofthe actual process of removing 

the litter by raking. During litter removal, some perennial 

plants, particularly grasses, were uprooted and some of the 

seed reserves in the litter may have been removed. 

Seeded species response to litter removal was somewhat 

unexpected. Recruitment of bluebunch wheatgrass, Lewis 

flax, and antelope bitterbrush showed no response to litter 

removal. Bottlebrush squirreltail seedling recruitment decreased significantly where litter removal occurred. A dry 

year in 1996 and the seeding method of broadcasting and not 

covering it contributed to an extremely low seeding response. 

This study indicated that under certain conditions, such 

as a drought, that Utah juniper canopy cover may actually 

act as a nurse plant for the understory species. However, to 

better understand the effect of Utah juniper canopy and 

litter removal on understory species this study needs to be 

continued to observe understory response over a wide range 

of environmental conditions. 

References __________________ __ 

Anderson, R. C.; Loucks, O. L.; Swain, A M. 1969. Herbaceous 

response to canopy cover, light intensity, and throughfall precipitation in coniferous forests. Ecology. 50:255-263. 

Armentrout, S. M.; Pieper, R. D. 1988. Plant distribution surrounding Rocky Mountain pinyon pine and one seed juniper in southcentral New Mexico. Journal of Range Management. 41: 139-143. 

Arnold, J. F. 1964. Zonation of understory vegetation around a 

juniper tree. Journal of Range Management. 17:41-42. 

Barney, M. A; Frischknecht, N. C. 1974. Vegetation changes following fire in the pinyon-juniper type of west-central Utah. Journal 

of Range Management. 27:91-96. 

Brotherson, J. D.; Osayande, S. T. 1980. Mineral concentrations in 

true mountain mahogany and Utah juniper in associated soils. 

Journal of Range Management. 33:182-185. 

Burkhardt, J. W.; Tisdale, E. W. 1976. Causes of juniper invasion in 

southwestern Idaho. Ecology. 57:472-484. 

Clary, W. P.1971. Effects of Utah juniper removal on herbage yields 

from springerville soils. Journal of Range Management. 24: 

373-378. 

Clements, C. D.; Young, J. A 1996. Influence of rodent predation on 

antelope bitterbrush seedling. Journal of Range Management. 

49:31-34. 

Daubenmier, R. 1959. A canopy-coverage method of vegetational 

analysis. Northwest Science. 33:43-64. 

Doescher, P. S.; Eddleman, L. E.; Vaitkus, M. R. 1987. Evaluation 

of soil nutrients, pH and organic matter in rangelands dominated 

by western juniper. Northwest Science. 61:97-102. 

Dye, K. L. II.; Ueckert, D. N.; Whisenant, S. G. 1995. Redberry 

juniper-herbaceous understory interactions. Journal of Range 

Management. 48:100-107. 

Engle, D. M.; Stritzke, J. F.; Claypool, P. L. 1987. Herbage standing 

crop around eastern red cedar trees. Journal of Range Management.40:237-239. 

Evans, R. A; Young, J. A 1970. Plant litter and establishment of 

alien annual weed species in rangeland communities. Weed 

Science. 18:697-703. 

Evans, R. A; Young, J. A 1985. Plant succession following control 

of western juniper (Juniperus occidentalis) with Picloram. Weed 

Science. 33:63-68. 

111 
Everett, R L.; Koniak, S. 1981. Understory vegetation in fully 

stocked pinyon-juniper stands. Great Basin Naturalist. 41: 

467-475. 

Farmer, M. E. 1995. The effects of anchor chaining pinyon-juniper 

woodland on watershed values and big game animals in central 

Utah. Master Thesis, Brigham Young University. Provo, UT. 

Horman, C. S.; Anderson, V. J. 1996. The effects of juniper litter 

depth and allelopathy on native species. Journal of Office of 

Research and Creative Activities. @Www.byu.edultmcbucs/tti 

journ95.htm 

Hurst, W.D. 1987. Management strategies within the pinyonjuniper ecosystem. In Everett (compiler). Proceedings- Pinyonjuniper conference. Reno, NV. 13-16 Jan. 1986. USDA For. Servo 

Gen. Tech. Rep. INT-215. Ogden, UT. pg. 391-396. 

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heterogeneity around individual perennial plants. Journal of 

Ecology. 81:683-692. 

Jameson, D. A 1961. Growth inhibitors in native plants of northern 

Arizona. USDA For. Serv., Rocky Mountain Forest and Exp. Sta. 

Res. Note 61, pg. 1-2. 

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Jameson, D. A 1970a. Degradation and accumulation of inhibitory 

substances from Juniperus osteosperma (Torr.) Little. Plant and 

Soil. 33:213-224. 

Jameson, D. A 1970b. Juniper root competition reduces basal area 

of blue grama. Journal of Range Management. 23:217-218. 

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McPherson, G. R; Rasmussen, G. A; Wester, D. B.; Masters, R A 

1991. Vegetation and soil zonation associated with Juniperus 

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and alligator juniper cover types of northern Arizona. Forest 

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phytomass production in a western juniper woodland. Great 

Basin Naturalist. 51:236-243. 

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34:501-506. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Resurvey of the Vegetation and Soils of 

Fishtail Mesa: A Relict Area in Grand 

Canyon National Park, Arizona 

N. J. Brian 

P. G. Rowlands 

D. A. Jameson 

The vegetation and soils of Fishtail Mesa in Grand Canyon National Park, Arizona, were studied in May 1958 by 

Jameson and others (1962) to provide management information and comparison for similar, grazed areas on the mainland's Forest Service lands. Fishtail Mesa is a 1,084 acre 

relict site at an elevation of about 6,000 feet, located in 

Grand Canyon National Park. It is characterized by two 

major plant communities: a pinyon pine-Utahjuniper woodland and a sagebrush-mutton grass shrubland or steppe. A 

resurvey was conducted in May 1996 to compare vegetative 

change after 38 years and to evaluate the site for long-term 

surveillance of ecological change. Seven and a half, permanent 800 foot "elbs" or line-strip transects were established 

in 1958; three and a half in the woodland and four in the 

shrubland. Vegetative methodology included line intercept, 

Parker loop data, tree data (including stem mapping, height, 

and canopy spread within a 20 foot strip centered over the 

transect) for all life stages, and three foot square plots 

located every 100 feet along the line intercept. A soil survey, 

landscape rephotography, comparison of historic aerial photography, estimates of mule deer population, floristic inventory, and preliminary faunal survey of the mesa were also 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

N. J. Brian is with the Science Center, Grand Canyon National Park, 

Grand Canyon, AZ. P. G. Rowlands is with Resources Management, Organ 

Pipe Cactus National Monument, Ajo, AZ. D. A. Jameson (retired) was with 

the Rocky Mountain Range and Experiment Station and currently lives in 

Trinidad, CO. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

completed. Global Positioning System coordinate data were 

collected to document the elb locations. 

The resurvey was made with participation of Jameson, 

using the same methodologies. Direct comparisons with the 

first survey are difficult due to the loss of the original field 

data. Only the 1962 journal article summary is available. 

Vegetation has not changed appreciably. On all elbs, a 

minor increase was detected for both pinyon and juniper. 

There is an apparent increase of pinyon seedling establishment. On the shrubland elbs, sagebrush has declined and 

mutton grass has increased, though the latter may reflect a 

difference in the minimum measurement unit from 0.1 inch 

in 1958 to 0.5 inch in 1996. Other species like joint-fir, 

prickly pear, and snakeweed have decreased. No recent 

evidence of wildfire was observed, though small groups of 

standing dead junipers suggest that fires did occur 80 to 100 

years ago. 

This information along with field data, photography, and 

herbarium samples will be archived in the Grand Canyon 

National Park Museum Collection. We recommend the site 

be established as a Federal Research Natural Area. 

113 
Diversity with Successional Status in the 

Pinyon-Juniper/Mountain Mahogany/ 

Bluebunch Wheatgrass Community Type 

Near Dutch John, Utah 

Allen Huber 

Sherel Goodrich 

Kim Anderson 

Abstract-Alpha and beta diversity and vegetative cover for 

Colorado pinyon (Pinus edulis Engeltn.) and Utah juniper 

(Juniperus osteosperma [Torr.] Little) understories of northerly 

exposures are compared at varying successional stages before and 

after disturbance. Plant diversity and species richness are highest 

in seral communities of alder-leaf mountain mahogany and 

bluebunch wheatgrass where pinyon and juniper canopy cover does 

not exceed 20 percent. Following disturbance at these sites, the 

response of native understory species was rapid and vigorous. 

Timely disturbance within the pinyon-juniper woodland sere appears necessary in order to maintain a responsive, productive, and 

diverse native understory. These studies indicate that pinyonjuniper canopy cover of about 20 percent is a critical point for the 

maintenance of native understory species. 

In the Great Basin, Everett (1987) noted that as pinyonjuniper crown cover increases, cover, productivity, and density of understory species decrease. In the Green River 

corridor of Daggett County, UT, similar relationships are 

evident. On many northerly exposures in the area, plant 

diversity and species richness are highest in seral communities where alder-leaf mountain mahogany (Cercocarpus 

montanus Raf.) and bluebunch wheatgrass (Elymus spicatus 

[Pursh] Gould) are commonly associated with approximately 

50 other vascular plants. Where crown cover of pinyonjuniper is less than 20 to 25 percent, response of these 

native understory species is rapid and vigorous following 

fire. When crown cover exceeds 30 percent, the understory 

trends toward depletion and the initial response following 

fire is slower and less vigorous. At 40 percent or more crown 

cover, many of the understory plant species have been 

purged from the community. Established stands of closed 

pinyon-juniper severely deplete understory seed reserves. 

Succession following fire in closed stands where crown cover 

of pinyon-juniper exceeds 40 percent is largely dependent 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Allen Huber is Range Technician, Duchesne District, Ashley National 

Forest, Duchesne, UT 8402l. Sherel Goodrich is Forest Ecologist, Ashley 

National Forest, Vernal, UT 84078. Kim Anderson is a Doctorate Student at 

Brigham Young University, Provo, UT 84602. 

114 

on seed migration to the site, creating ideal conditions 

for cheatgrass (Bromus sps.) and other invasive exotic species. Fire intervals frequent enough to maintain alder-leaf 

mountain mahogany and bluebunch wheatgrass communities in the Green River corridor are indicated to maintain 

native plant communities of high diversity and vigor. 

Eventual disturbance in closed stands of pinyon-juniper 

where understory communities have been depleted or 

purged will likely result in site occupation by invasive 

weeds or species seeded by land managers. 

Study Sites ________ _ 

The study sites are located within the Green River corridor in Daggett County of northeastern Utah. The corridor is 

within the Uinta Mountain Section defined by McNab and 

Avers (1994). The sites are within a land type composed ofa 

series of ridges and ravines formed by an alternate underlay of resistant Precambrian quartzite and highly erosive 

shales. Within the Green River corridor, continuous and 

many closed stands of Colorado pinyon (Pinus edulis Engelm.) 

and Utah juniper (Juniperus osteosperma [Torr.] Little) 

cover approximately 20,000 acres (8,100 ha) on the Ashley 

National Forest, and these stands extend eastward well 

beyond the National Forest boundary. Historically, seral 

communities were maintained by wildfire. However, fire 

suppression since the early 1900's has maintained areas 

already supporting mature pinyon and juniper trees and 

has allowed pinyon and juniper to invade other areas dominated by herbaceous plants and shrubs. Prescribed fire has 

been used in the Green River corridor during the 1980's and 

1990's to maintain viable and productive seral pinyonjuniper communities and to improve overall forage and 

habitat for big game animals. Livestock grazing was discontinued at the study sites in the mid-1960's. 

The land type on which the studies are located consists of 

two phases that are primarily influenced by exposure. On 

southerly exposures, native grass-forb communities are 

common in the early seral stage and are later succeeded by 

rubber rabbitbrush (Chrysothamnus nauseosus [Pallas] 

Britt.) and mountain big sagebrush (Artemisia tridentata 

var. pauciflora Winward and Goodrich). However, the potential for cheatgrass (Bromus tectorum L.) invasion and 

dominance on these exposures following disturbance is 

high, especially if pinyon-juniper crown closure existed 

prior to disturbance (Goodrich and Gale, these proceedings, 

Goodrich and Rooks, these proceedings). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 1-Site information for three study sites treated with 

prescribed fire. 

Study site number 

6-1 6-2 

Seral statusa Late Mid 

Stand age (years)a 300 80 

Year burned 1989 1993 

aSeral status and approximate stand age prior to prescribed burning. 

Table 2-Site information for five study sites not treated with 

prescribed fire. 

Study site number 

6-21 

Mid 

N/A 

1985 

6-24B 6-24C 6-24E 6-24G 6-24H 

Seral status 

Stand age (yrs) 

Mid 

70 

Mid 

150 

Late 

215 

Late 

140 

Mid 

N/A 

On northerly exposures, early seral native grasses and 

forbs are succeeded by a diverse shrub component consisting of alder-leaf mountain mahogany, low rabbitbrush 

(Chrysothamnus viscidiflorus [Hook.] Nutt.), snowberry 

(Symphoricarpos oreophilus Gray), serviceberry CAmelanchier alnifolia N utt.), and mountain big sagebrush. Approximately 50 native vascular plants are associated with 

this community. Bluebunch wheatgrass is the principal 

understory species. Cheatgrass is also present but generally at a much lower frequency than found on southerly 

exposures. 

This study includes eight study sites that are within 

3.5 miles (north-northwest) of Dutch John, UT and are no 

further than 2 miles apart. All are located on northerly 

exposures with gradients between 20 and 35 percent. 

Elevations for the sites range between 6,600 and 6,800 ft 

(2,012 and 2,073 m). Mean annual precipitation for the 

Dutch John area as indicated by the Flaming Gorge 

Weather Station is 12.50 inches (31.75 cm), of which 63 

percent is from April through September (Ashcroft and 

others 1992). 

Three of the eight study sites were burned by helitorch 

and aerial seeded in a cooperative project between the Utah 

Division of Wildlife Resources and the Ashley National 

Forest. Both northerly and southerly exposures were burned. 

The intensity and spread of fire was sufficient to achieve 

essentially 100 percent mortality of pinyon and juniper 

within the perimeter of each burn. Ring counts of pinyon and 

juniper trees at most ofthe study sites were used to approximate stand age (tables 1 and 2). 

Methods and Results 

A total of one hundred 19.69 by 19.69 inch (50 by 50 cm) 

sample plots were established along five permanently 

marked 30.5 m (100 ft) beltlines at each of the study sites. 

Quadrat frequency was determined for all plant species at 

most of the study sites as outlined by the U.S. Department 

of Agriculture, Forest Service (1993). Alpha (number of 

species per quadrat) and beta (total number of species) plant 

diversity was determined from quadrat frequency. Four 

hundred point samples were read at each study site to 

determine ground cover. Crown cover of woody species was 

also measured by line intercept along each of the five 

beltlines. Pre-burn and post-burn data was obtained from 

study sites 6-1 and 6-2 (tables 3 and 4). 

Data was taken from study site 6-2 before burning (1993) 

and 2 and 4 years after burning (1995 and 1997). Initial 

response of native understory species following fire at 

study site 6-2 was rapid and vigorous. Nearly all native 

species present before the burn were present after the burn. 

Of the shrubs, only mountain big sagebrush was absent 

following fire. A noticeable increase in alpha and beta was 

observed 4 years after burning. Some ofthe increase in beta, 

and possibly alpha, is due to the presence of seeded and 

annual species (table 4). All but two of the grass species 

increased in frequency from 1995 to 1997. Bluebunch wheatgrass was found with the highest frequency. Seeded grasses 

are present but are not dominant components at the site. 

Four years after burning, ground cover reached 85 percent 

of pre-burn potential and alder-leaf mountain mahogany 

recovered to nearly 85 percent of its pre-burn crown cover. 

At study site 6-1, where crown cover of pinyon-juniper 

was about 60 percent before burning, the understory community had been reduced by pinyon and juniper compe~ition. 

Initial response of native species after fire was sluggIsh at 

best. The increase in plant diversity is due to the presence 

Table 3-Comparison of diversity, ground cover, and woody species crown cover pre-fire and post-fire at study sites 6-2 and 6-1. 

Diversity Ground Woody species crown coverS 

Study Year Alpha Beta cover P-J CEMO AMAL SYOR ARTR CHVI 

- - - - - - - - - - - - - - - - - - - - - - - - - - Percent - - - - - - - - - - - - - - - - - - - - - - - - - -

6-2 1993 7.9 51 95 11.2 11.4 4.4 8.8 10.9 0.6 

6-2 1995 7.6 55 48 0.0 7.5 1.6 8.4 0.0 3.4 

6-2 1997 8.3 68b 74 0.0 9.5 2.6 10.5 0.0 2.0 

6-1 1989 1.4 17 84 62.3 1.0 0.0 0.0 0.0 0.0 

6-1 1993 4.7 38c 57 0.0 0.0 0.0 0.0 0.0 0.0 

ap-J = pinyon-juniper, CEMO = Cercocarpus montanus, AMAL = Amelanchier alnifolia, SYOR = Symphoricarpos oreophilus, ARTR = Artemisia 

tridentata, CHVI = Chrysothamnus viscidiflorus. 

bSixteen of the 68 species were either seeded or were annuals. 

CEighteen of the 38 species were either seeded or were annuals. 

USDA Forest Service Proceedings RMRS-P-9. 1999 115 
Table 4-Comparison of number of species pre-fire and post-fire at study sites 6-2 and 6-1. 

Number of species 

Study Year Graminoids Forbs Shrubs Seeded Annuals 

6-2 1993 10 31 8 0 5 

6-2 1995 13 36 6 6 9 

6-2 1997 18a 43c 7 6 10 

6-1 1989 4 10 2 0 0 

6-1 1993 11 b 25d 3 6 12 

·Ot the 18 graminoid species, four were seeded and two were annuals. 

bOf the 11 graminoid species, five were seeded and one was an annual. 

cOt the 43 torbs species, two were seeded. 

dOt the 25 forb species, one was seeded. 

of seeded and annual species. Seeded grasses and annuals 

recorded high frequencies in 1993. AIder-leaf mountain 

mahogany and bluebunch wheatgrass are represented (frequency values of 2 and 1) at the study site but are minor 

components in the present community. Ground cover was 

nearly 70 percent of pre-burn potential. 

Data obtained from eight study sites indicate that as 

crown cover of pinyon-juniper increases, alpha and beta 

diversity and crown cover of alder-leaf mountain mahogany 

decrease (table 5). Alpha and beta values were high and 

remained stable to 20 to 25 percent pinyon-juniper crown 

cover. Under these conditions, alder-leaf mountain mahogany increased in crown cover. Alpha and alder-leaf 

mountain mahogany crown cover showed decline at about 

30 percent pinyon-juniper crown cover. At 50 percent crown 

cover, alpha and beta were significantly reduced, and alderleaf mountain mahogany had been essentially purged from 

the community. 

Discussion and Management 

Implications ________ _ 

Initial response of native understory species following fire 

correlates closely with the per'Cent crown cover of pinyon 

and juniper trees. Our studies indicate that the understory 

is most productive, diverse, and responsive to disturbance 

when pinyon-juniper crown cover is at or below 20 percent. 

Initial response following fire at study site 6-2 was rapid 

and vigorous. The annual stage described by Barney and 

Frischknecht (1974) was essentially bypassed, and the perennial grass-forb stage was relatively short (approximately. 

2 years). Alpha and beta had recovered to pre-burn levels. 

Most of the shrubs present at the site sprouted after fire, 

and alder-leaf mountain mahogany had nearly reached 

pre-burn crown cover in only 4 years. 

When pinyon-juniper crown cover exceeds 20 to 30 percent, thinning of the understory seems to accelerate. The 

data indicate that beta remains stable but alpha begins to 

decline. Beyond 30 percent, there is a rapid decline in 

understory species and substantial decrease in alder-leaf 

mountain mahogany crown cover. By the time pinyonjuniper crown cover reaches 50 percent, the understory and 

soil seed reserves have been depleted, and many plant 

species have been purged from the community. Crown cover 

of alder-leaf mountain mahogany appears to be a positive 

indicator for vascular plant diversity while crown cover of 

pinyon and juniper appear to be negative indicators. 

Our studies indicate that succession and management of 

pinyon-juniper woodlands of the Green River corridor can 

be correlated with percent crown cover of pinyon and 

juniper trees. Age of stand appears to be a less reliable 

indicator (compare stand ages and pinyon-juniper crown 

cover percentages for study sites 6-24C, 6-24E, 6-24G, and 6-

1). Fire intervals that keep pinyon-juniper crown cover 

below 20 to 25 percent is indicated to maintain responsive, 

productive, and diverse alder-leaf mountain mahogany 

and bluebunch wheatgrass communities. Our findings 

Table 5-Alpha and beta diversity and crown cover of shrubs and alder-leaf mountain mahogany (CEMO) 

in relation to crown cover of pinyon and juniper (P-J). 

Diversity Total shrub Crown cover 

Study site Year Alpha Beta crown cover CEMO P-J 

- - - - - - - - - - - - Percent - - - - - - - - - - - -

6-2 1993 7.9 51 36.4 11.4 11.2 

6-2 1995 7.6 55 21.1 7.5 0.0 

6-2 1997 8.3 68 24.8 9.5 0.0 

6-21 1993 9.1 49 23.0 12.1 0.0 

6-248 1997 7.2 62 38.7 29.6 18.5 

6-24H 1997 N/A N/A 27.5 22.9 27.1 

6-24C 1997 4.5 50 21.6 12.7 29.2 

6-24E 1997 3.2 37 0.9 0.9 53.9 

6-24G 1997 2.7 30 0.2 0.0 62.1 

6-1 1989 1.4 17 1.0 1.0 62.3 

6-1 1993 4.7 38 0.6 0.0 0.0 

116 USDA Forest Service Proceedings RMRS-P-9. 1999 
concur with Doughty (1987) who reported that understory 

species begin to decline when trees reach one-third of their 

climax potential (approximately 20 percent crown cover). 

Where understory species have been depleted or purged 

from the community, invasive species such as cheatgrass 

can be expected to occupy these sites after disturbance if 

seeding is not used to control their invasion. 

References ---------------------------------- Ashcroft, G. L.; Jensen, D. T.; Brown, J. L. 1992. Utah climate. 

Logan, UT: Utah State University, Utah Climate Center. 125 p. 

Barney, M. A.; Fischknecht, N. C. 1974. Vegetation changes following fire in the pinyon-juniper type of west-central Utah. Journal 

of Range Management. 27(2): 91-96. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Doughty, J. W. 1987. The problems with custodial management of 

pinyon-juniper woodlands. In: Everett, R. L., compo Proceedingspinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. 

Tech. Rep. INT -215. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station: 29-33. 

Everett, R. L. 1987. Plant response to fire in the pinyon-juniper 

zone. In: Everett, R. L., compo Proceedings-pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 152-157. 

McNab, W. H.; Avers, P. E., comps. 1994. Ecological subregions of 

the United States: Section descriptions. Administrative Pub!. 

WO-WSA-5. Washington, DC: U.S. Department of Agriculture, 

Forest Service. 267 p. 

U.S. Department of Agriculture, Forest Service. 1993. Rangeland 

ecosystem analysis and management handbook. FSH 2209-2l. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Region. 

117 
Diseases and Environmental Factors of the 

Pinyon-Juniper Communities 

D. J. Weber 

E. D. Bunderson 

J. N. Davis 

D. L. Nelson 

A. Hreha 

Abstract-The pinyon-juniper woodland is the dominant ecosystem in Utah. While it is a very successful ec()system, it is not without 

its disease problems. The limiting soil nutrients appear to be 

nitrogen, phosphorous, and potassium. Temperature and moisture 

gradients are limiting factors in the growth of pinyon and juniper. 

Juniper decline appears to be related to drought and temperature stress and increased salts. A number of pathogens occur on 

Pinus edulis and Juniperus osteosperma. The most frequent pathogens on junipers are the rust fungi. Mistletoe was more common on 

pinyon than juniper but mistletoe infection has an impact on both. 

The pinyon-juniper woodland is a widespread vegetation type in the Southwestern United States that is estimated to cover from 40 to 50 million hectares (Allred 1964; 

Tausch and Tueller 1990). The pinyon-juniper vegetation 

provides a source of fuel, building materials, charcoal, pine 

nuts, Christmas trees, and folk medicines (Cronquist and 

others 1972; Gallegos 1977; Hurst 1977; Lanner 1975; 

Tueller and others 1979). About 80 percent of the acreage is 

grazed by livestock and wildlife (Bunderson and others 

1986b; Clary 1975). In Utah, this ecosystem is a large 

component (62,705 km2 or 28.6 percent) of the vegetation 

(Kuchler 1964). The pinyon-juniper woodlands are valued 

for their watershed, aesthetic, and recreational values 

(Gifford and Busby 1975). The pinyon-juniper woodlands 

also have a range of diseases. They range from non-pa thogen 

types (environmental factors) to specific pathogens. Both 

types will be discussed in this paper. The purpose of this 

manuscript is to review the non-pathogenic factors and 

pathogens present in pinyon-juniper woodlands. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 Septeinber 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.s. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

D. J. Weber is with the Department of Botany and Range Science and 

E. D. Bunderson (deceased) was with the Department of Instructional 

Science, Brigham Young University, Provo, UT 84602. J. N. Davis and D. L. 

Nelson are with the USDA Forest Service, Rocky Mountain Research 

Station, Shrub Sciences Laboratory, Provo, UT 84606. A. Hreha is with the 

Red Butte Botanical Garden, University of Utah, Salt Lake City, UT 84112. 

118 

Influence of Environmental 

Factors ___________ _ 

Soil and Mineral Factors 

Soil samples and foliage samples (255 trees) were collected from 17 pinyon-juniper sites throughout Utah (fig. 1, 

table 1). Mineral analysis of soils and leaf samples were 

determined. The mineral concentration was correlated with 

the mineral concentrations of the leaves at the different 

sites. Statistical and factorial analyses suggested that the 

primary limiting soil nutrients in the native soils were 

nitrogen, phosphorous, and potassium. The linear correlation coefficient of foliage mineral composition and soil mineral composition was 0.66 for nitrogen and potassium 

and 0.49 for sodium and phosphorous. Rotated orthogonal 

Figure 1-Location of the 17 pinyon-juniper study 

sites in Utah. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 1-Specific names of the 17 primary 

pinyon-juniper study sites in Utah. 

Number Site name 

Jackson Springs 

2 Tobin Bench 

3 Peters Point 

4 Alkali Ridge 

5 Cyclone Flat 

6 Indian Peak 

7 Ephraim 

8 Manti 

9 Black Mountain 

10 Triangle Mountain 

11 Beaver Ridge 

12 Gordon Creek 

13 Dutch John 

14 Taylor Flat 

15 Rabbit Gulch 

16 Henry Mt (Stevens Narrows) 

17 Henry Mt (Airplane Flat) 

factors from varimax factor analysis were 0.79 for nitrogen, 

0.73 for phosphorous and 0.50 for potassium. Correlation of 

factors greater than an absolute value of 0.25 are significant 

(Bunderson and others 1986a). Increased concentration of 

sodium resulted in decreased growth of junipers which 

would indicate that J. osteosperma is a salt-sensitive species. Temperature and moisture gradients were also distinct 

growth limiting factors in this ecosystem (Bunderson and 

others 1985). 

Juniper Decline, a Non-Pathogenic Disease 

Juniper decline is common in southwestern Utah. The 

characteristic symptom is for the distal foliage to become 

chlorotic and die. Mortality progresses along twigs until 

whole branches or the entire tFee dies. While juniper decline 

was observed in Natural Bridges National Monument and 

Needles area of Canyon land National Park, no pathogenic 

agent appeared to be responsible for the decline problem. 

There did not appear to be any high correlation between 

high or low amounts of minerals in the soil. It is suggested 

that the juniper decline is a combination of drought and 

temperature stress which reduces the water resources. The 

increased uptake of salts result in complexing of the iron, 

magnesium and calcium to form complex crystals in the 

leaves which are characteristic of the decline symptoms 

(Weber and others 1995). 

Diseases Caused by 

Organisms _________ _ 

Diseases Reported for Pinyon Pine 

The printed literature was searched by computer and 

manual searches of several western disease herbariums 

were done. The States covered by the herbarium searches 

were Arizona, Colorado, Idaho, Nevada, New Mexico, Oregon, 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Utah, Wyoming, and Washington. The reported pathogens 

on Pinus edulis were: 

Acanthophysium albida (Gilbertson and others 1974) 

Armillaria mellea (Plant Disease Index 1960) 

Arceuthobium campylopodum (Peterson 1961) 

Arceuthobium divaricatum (Hreha and Weber 1979) 

Coleosporium crowellii (Christenson and Peterson 1961) 

Coleosporium jonesii (Gilbertson and McHenry 1969) 

Coleosporium ribicola (Peterson 1962) 

Cronartium occidentale (Plant Disease Index 1960) 

Dacryobolus karstenii (Gilbertson and others 1975) 

Heterobasidion annosum (Tegethoff 1973) 

Leptographium wageneri (Landis and Helburg 1976) 

Phellinus pini (Plant Disease Index 1960) 

Phoradendronjuniperinum (Hreha and Weber 1979) 

Tomentella chlorina (Gilbertson and others 1974) 

Verticicladiella sp. (Wagener and Mielke 1961) 

Verticicladiella wagenerii (Walters and Walters 1977) 

Diseases Reported for Junipers 

The reported pathogens on Juniperus osteosperma (Utah 

Juniper) were: 

Antrodia ferox (Hawksworth 1950) 

Daedaleajuniperina (Gilbertson 1975) 

Diplomitoporus rimosus (Hedgecock 1912) 

Fomesjuniperinus (Bethel 1918) 

Gymnosporangium harknessianum (Plant Disease 

Index 1960) 

Gymnosporangium inconspicuum (Bethel 1918) 

Gymnosporangiumjuvenescens (Goodding 1919) 

Gymnosporangium kernianum (Bethel 1918) 

Gymnosporangium multiporum (Bethel 1918) 

Gymnosporangium nelsonii (Bailey 1970) 

Gymnosporangium speciosum (Bethel 1918) 

Poria rimosa (Gill 1941) 

Pyrofomes (Fomes) demidoffii (Gilbertson 1974) 

Trametes sepium (Hawksworth 1950) 

Uredo phoradendri (Hawksworth 1952) 

Correlation of Diseases and 

Environment 

Pathogens and Physiological Diseases 

The diseases present on J. osteosperma was determined 

on 17 sites in Utah (fig. 1). The most frequent pathogen on 

the research sites was Gymnosporangium (rust fungi). 

Gymnosporangium inconspicuum was the most common 

rust fungus followed in frequency and severity by G. nelsonii, 

G. kernianum and G. speciosum. Mold-mildew type of diseases were correlated with high summer temperature and 

fall precipitation. Wood rot was common and correlated 

with low winter temperatures and low soil nitrate. Needle 

blight, shoot dieback, and needle cast symptoms were common and considered abiotic in origin. Needle blight was 

correlated with higher soil salinity. Mistletoe, Phoradendron 

juniperinum was present in seven sites (Bunderson and 

others 1986b). 

119 
Table 2-Percent infection comparing pinyon 

and juniper on rim, forest, and burned 

areas of the south rim of the Grand 

Canyon. 

Pinyon 

Juniper 

Rim 

32.3 

46.8 

Forest 

30.6 

31.8 

Burned 

0.02 

0.02 

Mistletoe on Pinyon and Juniper 

The distribution and effects of mistletoes on the pinyonjuniper vegetation along the south rim ofthe Grand Canyon 

was determined (Hreha and Weber 1979). Arceuthobium 

diuaricatum, which infects Pinus edulis, is spread by a 

forced ejection mechanism of the mistletoe. Juniperus osteosperma is infected by Phoradendronjuniperinum, which 

is spread by birds. Fire was the most effective factor in 

limiting the spread of the mistletoes. The trees that had 

regrown in the burned areas were the only areas devoid of 

mistletoe infection (table 2). The incident of infection increases as trunk diameter and height increases in both 

pinyon and juniper (Hreha and Weber 1979). 

While in some cases, the non-pathogenic factors and the 

pathogens cause death of the trees, no control measures are 

used. On the other hand, the replacement seedlings appear 

to be more than adequate to replace lost trees. 

References ---------------------------------- Allred, B. W. 1964. Problems and opportunities on U.S. grasslands. 

American Hereford Journal. 54: 70-72. 

Author not listed. 1960. Index of Plant Diseases in the United 

States. U.S. Dept. Agric. Handbook. No. 165. Washington, DC. 

531 p. 

Bailey, H. E. 1970. Gymnosporangium nelsonii Arth. on Junipe1'lls 

osteosperma (Torr.) Little. U. Calif., Berkeley Herb. No. 1450623. 

Bethel, E. 1918. Fomesjuniperinus (Schrenk) Sacco & Syd. in Sacco 

on Juniperus osteosperma (Torr.) Little. Rocky Mtn. For. & Ran. 

(Colo.) Herb. No. 4242-G. 

Bethel, E. 1918. Gymnosporangium inconspicuum Kern on Junipe- rus osteosperma (Torr.) Little. Rocky Mtn. For. & Ran. (Colo.) 

Herb. No. 4851-P. 

Bethel, E. 1918. Gymnosporangium Iwrnianum Bethel on Juniperus osteosperma (Torr.) Little. Shrub Sciences Laboratory, Provo, 

UT. Herb. No. 186. 

Bethel, E. 1918. Gymnosporangium multiporum Kern on Junipe- rus osteosperl1la (Torr.) Little. Shrub Sciences Laboratory, Provo, 

UT. Herb. No. 220. 

Bethel, E. 1918. Gymnosporangiul1l speciosum Peck on Juniperus 

osteosperma (Torr.) Little. Rocky Mtn. For. & Ran. (Colo.) Herb. 

No. 4358-P. 

Bunderson, E. D.; Weber, D. J. 1986a. Foliar nutrient composition 

ofJ uniperus osteosperma and environmental interactions. Forest 

Science. 32: 149-156. 

Bunderson, E. D.; Weber, D. J.; Nelson, D. L. 1986b. Diseases 

associated with Juniperus osteosperma and a model for predicting their occurrence with environmental site factors. Great Basin 

Naturalist. 46: 427-440. 

Bunderson, E. D.; Weber, D. J.; Davis, J. N. 1985. Soil mineral 

composition and nutrient uptake in Juniperus osteosperma in 17 

Utah sites. Soil Science. 139: 139-148. 

Christenson, J. A.; Peterson, R. S. 1961. Coleosporium c/'Owellii 

Cummins on Pinus edulis Engelm. Shrub Sciences Laboratory, 

Provo, UT. Herb. No. 979. 

Clary, W. P. 1975. Present and future multiple-use demands on 

the pinyon-juniper type. In: The pinyon-juniper ecosystem: A 

symposium. Utah Agri. Exper. Station. 194 p. 

Cronquist, A.; Holmgren, A. H.; Holmgren, N. H.; Reveal, J. L. 1972. 

Intermountain flora. vol. 1. New York Botanical Garden, New 

York: Hafner Publishing. 

120 

Gallegos, R. R. 1977. Forest Practices needed for the pinyon-juniper 

type. In: Ecology, uses and management of pinyon-juniper 

woodlands. USDA Forest Service General Technical Report 

RM-39. 48 p. 

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Gilbertson, R. L. 1974. Fomes demidoffii (Lev.) Cooke on Juniperus 

osteosperma (Torr.) Little. Univ. Ariz. Herb. No. RLC 7090 

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Gilbertson, R. L.; Burdsall, H. H., Jr.; Larsen, M. J. 1975. Notes 

on wood rotting hymenomycetes in New Mexico. Southwest 

Naturalist. 19: 359-360. 

Gilbertson, R. L.; Martin, K J.; Lindsey, J. P. 1974. Annotated check 

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USDA Forest Service Proceedings RMRS-P-9. 1999 
Methods in Historical Ecology: A Case Study 

of Tintic Valley, Utah 

Jeffrey A. Creque 

Neil E. West 

James P. Dobrowolski 

Abstract-Through use of repeat photography, archival research, 

and field observation to reconstruct landscape vegetation patterns 

and changes across a 120 year period in the upper Tintic Valley of 

central Utah, researchers found significant changes in landscape 

vegetation pattern over time, including change in pinyon-juniper 

woodland area. Previously reported massive woodland harvest 

associated with early mining, domestic and agricultural activities 

elsewhere in the Intermountain West also took place in Utah. The 

impact on woodland area of the agricultural "bull" fence alone 

was significant. More recent study area woodland expansion also 

occurred. Because intensive industrial activity associated with 

development of the Tintic Mining District occurred prior to the 

taking of the study's 1911 photographs, those photos failed to 

reflect presettlement, or even early settlement, vegetation conditions. Overall, results suggest that historical ecological studies 

must employ a range of overlapping methodologies to accurately 

interpret the nature and direction oflandscape vegetation change. 

Such information is useful for managing regional ecosystems now 

and into the future. 

This study was undertaken to provide a historical context for proposed long-term watershed research in pinyonjuniper woodlands in Tintic Valley, Juab County, Utah. The 

study objective was to describe and, where possible, quantify 

landscape changes occurring in the study area from the 

time of Euroamerican settlement to the modern period. 

Reported here are results pertaining specifically to historic 

impacts on the pinyon-juniper woodlands of the study area. 

Ecological histories have been widely used to characterize 

changes in vegetation cover over time (Bahre 1991; Hadley 

and Sheridan 1995; Hastings and Turner 1965). Such studies can be a useful point of departure for managers seeking 

guidelines for managing regional ecosystems now and into 

the future. Because the historical ecological record is commonly fragmented, a variety of techniques are generally 

employed to achieve research objectives. In this study, no 

single methodology was able to provide a complete picture 

of change in the study area. Repeat photography, archival 

research, oral histories, field observations and the regional 

ecological literature all provided clues for understanding 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Jeffrey A. Creque is a Land Stewardship Consultant, P.O. Box 1004, 

Bolinas, CA 94924. Neil E. West and James P. Dobrowolski are Professor and 

Associate Professor, respectively, Department of Rangeland Resources, Utah 

State University, Logan, UT 84322-5230. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

changes in the Tintic landscape over time. The results of 

this study support the view that historical ecological studies must employ a range of overlapping methodologies to 

accurately interpret the nature and direction of landscape 

change. 

Materials and Methods -----------------

Archival Research 

This study included an intensive survey of archival materials for references to Tintic Valley vegeta tion, records of ore, 

fuelwood and charcoal production, smelting and milling 

activities, and human population in the Valley in the era of 

biomass fuels. From this information, estimates of early 

settlement era (1870-1900) industrial, agricultural, and 

domestic fuel wood consumption were derived. 

Oral Histories and Field Observations 

Oral histories, maps, field measurements, and historical 

photographs were employed to quantify the settlement era 

use of juniper trees for livestock fencing ("bull fence") within 

the study area. 

Domestic fuelwood consumption was estimated from 

population figures for the area (USDC 1910, USDI 1900, 

1890, 1880), using an assumed fuelwood consumption rate 

of one cord per person, per year (Bahre 1991; Hadley and 

Sheridan 1995). 

Quantities of cordwood and charcoal consumed in Tintic 

Valley mills and smelters in the biomass fuel era (1869-

1880) were estima ted using published figures for ore prod uction (Butler and others 1920; Heikes 1919) and fuel consumption for the era (Raymond 1873). 

Estimates of woodland area cleared for fuelwood were 

derived from published estimates of cordwood yields from 

pinyon-juniper woodlands (Young and Budy 1986, 1979). 

Wood used in agricultural fence construction was similarly 

translated to hectares cleared using woodland density estimates derived by applying a plotless density technique 

(Bonham 1989; Cottam and Curtis 1956) to witness tree data 

from the 1872-1874 General Land Office Survey of the study 

area (Gorlinski 1874). 

Paired Photographs 

1911 photographs of portions of the study area (Lindgren 

and Loughlin 1919), obtained through the national archives of the U.S. Geological Survey, were rephotographed 

in 1995, using methods outlined in Rogers (1982) and 

Rogers, Malde and Turner (1984). 

121 
Results __________ _ 

Woodland Harvest 

Domestic Fuelwood-Domestic fuelwood consumption 

for the 1870-1900 period was estimated to have been 74,000 

cords, as follows: 

Decade: 1870-79 1880-89 1890-99 

Cords: 12,250* 19,520* 42,230 

* incomplete data 

Industrial Fuels-Assuming 12 cords of wood or 33 

bushels of charcoal required to process 10 tons of ore under 

favorable conditions (Raymond 1873), roughly one cord of 

wood or its charcoal equivalent was consumed per ton of ore 

processed. With 132,500 tons of ore processed within the 

District between 1870 and 1890, (Raymond 1873) a conservative estimate of cordwood consumed in processing Tintic's 

ores in that decade is 132,500 cords. Note that this figure is 

both conservative with respect to ore processing and ignores 

the use of wood fuels for brick making, industrial purposes 

other than ore processing, and the preprocessing of ores by 

small, independent operators. 

Non-Fuel Uses-Figure 1 shows a bull fence located 

within or immediately adjacent to the study area at the 

Homansville Mill site (Seamons 1992). Field measurements 

of bull fence remnants in the study area yielded a mean of 

3.9 trees per meter offence. Measurements derived from this 

photograph yielded an estimate of 7.7 stems per meter. At 

least 40.65 km of McIntyre Ranch boundary fence in or 

near the study area are known to have been fenced in this 

manner (Mr. Steele McIntyre, personal communication, 

August 1995), resulting in an estimate of 158,500 stems 

used in fencing the McIntyre Ranch alone. Note that this 

figure does not include cross fencing with bull fence, which 

field observation also revealed, nor does it include posts used 

to support wire fence erected elsewhere in the study area. 

The figure also ignores other uses of the District's woodland 

trees; as mine timbers, or ties for narrow gauge railways 

associated with the District's mines. Consequently, while 

the figure of 158,500 stems was used as an estimate of the 

number of trees harvested for non-fuel uses in the Tintic 

area in the early settlement era, it is believed to be an 

extremely conservative estimate. 

Total W oodland Harvest-Total woodland harvest for 

the 1870-1910 period is estimated to have been between 

9,795 and 86,397 hectares, as follows: 

Industrial fuels 4,469-53,620 ha 

Domestic fuels 2,497 -29,960 ha 

Other uses 2,830 ha 

Total 9,795-86,397 ha 

The wide range in estimated harvest area is due to the range 

in estimated cordwood yields (1-12 cords per acre or 2.47-

29.64 cords per ha) from pinyon-juniper woodlands (Young 

and Budy 1979). 

Photographic Pairs 

Figures 2 through 11 are paired photographs showing 

vegetation changes in the East Tintic Mountains across 84 

years. Captions are based upon those of Lindgren and 

Loughlin (1919). Each photograph's USGS archive number 

follows Loughlin's name. 

122 

Figure 1-Bull fence, Homansville Mill, 1870's. 

(Seamons 1992). 

Without exception, these photographs show an increase in 

the areal extent and/or density of woodland vegetation 

across the 84 year interval. Particularly dramatic is the 

increase in woodland cover in the north end of the Valley as 

seen in figure 2 and in the saddle of Quartzite Ridge, 

figure 3. Significant increase in woodland cover is also 

apparent on the south-facing slopes north of Ruby Hollow, 

above the site of Silver City (fig. 4-6). 

The dynamic nature of Tintic Valley's vegetation across 

the 1911-1995 interval can be seen in figures 7 and 8. In both 

the 1911 and 1995 photographs, the west slope of Sunrise 

Peak is dominated by non-woodland vegetation. Rather 

than reflecting stasis in vegetation physiognomic type on 

this site, however, these apparently similar vegetation patterns bracket a period of woodland establishment, crown 

closure, catastrophic fire and management intervention. On 

this site in 1911, a young woodland stand can be seen on the 

lower slopes of the mountain. By 1994, the entire slope was 

covered with a dense stand of juniper, which burned in a fire 

in August of that year. By the time the photograph was 

retaken in 1995, the area had been chained and seeded to 

crested wheatgrass, at least superficially recreating vegetation conditions reflected in the 1911 photograph. Note the 

standing dead trees visible on the steeper upper slopes ab.ove 

the chaining. Thus, a complete cycle of woodland estabhshment and elimination by crown fire occurred within the 

temporal interval of this set of photographs. 

These photographs cover that part of the study area in 

which towns and mines were concentrated and where several early smelters and mills were also located (Creque 

1996). Vegetation patterns visible in the distance in figures 2 and 4, suggest, however, that the increase in woodland extent and density from approximately 1911 to 1995 

has been generally the case across the Valley. 

Discussion and Conclusions __ _ 

In this study, an exhaustive archival survey failed to 

identify useful landscape photographs ofthe study area prior 

to a set of USGS photographs taken in 1911 (Loughlin 1911). 

While repeat photographs taken over 80 years later (Creque 

1996) show a clear increase in woodland cover and tree 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Figure 2-Foothills northwest of Eureka and head of Tintic Valley. Above: 1911 (Loughlin 18). Below: 1995. 

USDA Forest Service Proceedings RMRS-P-9. 1999 123 
Figure 3-East-west fault south of the saddle east of Quartzite Ridge. Above: 1911 (Loughlin 19). Below: 1995. 

124 USDA Forest Service Proceedings RMRS-P-9. 1999 
Figure 4-East Tintic Mountains, looking north from Treasure Hill across Ruby Hollow. Above: 1911 

(Loughlin 6). Below: 1995. 

USDA Forest Service Proceedings RMRS-P-9. 1999 125 
Figure 5-East Tintic Mountains, looking north from Treasure Hill across Ruby Hollow. Above: 1911 (Loughlin 5). Below: 1995. 

126 USDA Forest Service Proceedings RMRS-P-9. 1999 
Figure 6-East Tintic Mountains, looking north from Treasure Hill across Ruby Hollow. Above: 1911 (Loughlin 4). 

Below: 1995. 

USDA Forest Service Proceedings RMRS-P-9. 1999 127 
Figure 7-Sunrise Peak, looking south from Treasure Hill. Above: 1911 (Loughlin 9). Below: 1995. 

128 USDA Forest Service Proceedings RMRS-P-9. 1999 
Figure a-Volcano Ridge, looking south from Treasure Hill. Above: 1911 (Loughlin 10). Below: 1995. 

USDA Forest Service Proceedings RMRS-P-9. 1999 129 
Figure 9-Mammoth and surrounding mountains. Above: 1911 (Loughlin 22). Below: 1995. 

130 USDA Forest Service Proceedings RMRS-P-9. 1999 
Figure 10-Mammoth and surrounding mountains. Above: 1911 (Loughlin 23). Below: 1995. 

USDA Forest Service Proceedings RMRS-P-9. 1999 131 
Figure 11-Mammoth and surrounding mountains. Above: 1911 (Loughlin 24). Below: 1995. 

132 USDA Forest Service Proceedings RMRS-P-9. 1999 
density, interpretation of pre- and post-settlement vegetation dynamics from these photographic pairs alone could 

easily lead to erroneous conclusions (Lanner 1977, 1981). 

Because intensive industrial activity associated with development of the Tintic Mining District occurred prior to the 

taking of the 1911 photographs employed in this study, 

those photographs failed to reflect presettlement, or even 

early settlement, vegetation conditions. Rather than revealing presettlement conditions of the study area landscape, 

Loughlin's photographs reflect conditions after 40 years of 

intensive resource exploitation associated with the early 

industrial development of one ofthe West's most productive 

mining Districts. For the first decade ofthat period, biomass 

constituted the only fuel available for operation of some 30 

mills and smelters in the District, many of which were 

located on or near sites shown in Loughlin's photographs. 

In the same decade, a rapidly growing human population 

depended exclusively on biomass fuels for domestic purposes, and biomass fuels continued to meet a significant 

proportion of industrial and domestic fuel needs into the 

20th century (Creque 1996). Livestock fencing, timbering 

requirements-particularly for the smaller mines and ties 

for the District's narrow gauge railroads-similarly drew 

heavily upon the District's woodlands. 

While paired, multitemporal photographs provide indisputably valuable information regarding site or landscape 

changes across the temporal interval of the photographic 

pairs, a number of factors contribute to render interpretation of the ecological significance of vegetation changes 

documented by repeat photography alone problematic 

(Lanner 1977, 1981). These include the fact that early photography rarely records pre-Euroamerican settlement 

landscape conditions, either because such settlement and 

attendant land use changes predated the advent of photographic technology, or because landscape conditions did not 

capture the attention of the early photographer(s) of a 

particular region. Early photography tended to focus upon 

images of daily life in and around settlements, with the 

surrounding landscape playing an incidental role, if any, in 

the photographic image. Even where the landscape or plant 

communities were the subjects of interest, it was common for 

the photographer to limit his range of focus to those areas 

immediately adjacent to transportation corridors, such as 

roadsides or railroad corridors. 

This study reveals the magnitude of early agriculture, 

domestic acti vi ties and biomass-fueled ind ustry on the woodlands of Tintic Valley. Though not, to the knowledge of 

these investigators, previously reported, the impact of the 

bull fence, a common feature of early Intermountain 

ranches, was alone found to be an important factor in postsettlement reduction in tree cover. While these historical 

impacts on the pinyon-juniper woodlands of Tintic Valley 

appear extreme, they are consistent with reports from 

mining districts elsewhere in the region (Lanner 1981; 

Young and Budy 1979). 

The study contributes to an improved understanding ofthe 

historic-era dynamics ofthe Tintic landscape and provides 

a point of reference for current and future management of 

USDA Forest Service Proceedings RMRS-P-9. 1999 

the Valley landscape ecosystem. In a broader context, the 

study underscores the need for multiple lines of investigation in historical ecological research. 

References --------------------------------------- Bahre, c. J. 1991. A legacy of change: historic human impact on 

vegetation in the Arizona borderlands. University of Arizona 

Press, Tucson, Arizona, U.S.A. 

Bonham, C. D. 1989. Measurements for terrestrial vegetation. John 

Wiley & Sons. NY, NY, U.S.A. 

Butler, B. S., G. F. Loughlin, V. C. Heikes and others. 1920. The ore 

deposits of Utah. USDI Geological Survey 111. US. GPO, Washington, DC, US.A. 

Cottam, G. and J. T. Curtis. 1956. The use of distance measures in 

phytosociological sampling. Ecology 37(3):451-460. 

Creque, J. A. 1996. An ecological history of Tintic Valley, Juab 

County, Utah. Unpublished doctoral dissertation. Department of 

Rangeland Resources, Utah State University, Logan, Utah, U.S.A. 

Gorlinski, J. 1872-1874. Field Notes. General Land Office Survey, 

Townships 9,10 and 11S, Ranges 2,3,4 and 5 W, Salt Lake 

Meridian, Utah. Microfiche USDI Bureau of Land Management, 

Salt Lake City, Utah, US.A. 

Hadley, D. and T. E. Sheridan. 1995. Land use history of the San 

Rafael Valley, Arizona (1540-1960). USDA Forest Service. Rocky 

Mountain Forest and Range Experiment Station General Technical Report RM-269. Fort Collins, Colorado, US.A. 

Hastings, J. R. and R. M. Turner. 1965. The changing mile. University of Arizona Press. Tucson, Arizona, U.S.A. 

Heikes, V. C. 1919. History of mining and metallurgy in the Tintic 

district. Part II, pp. 105-117 in W. Lindgren and G. F. Loughlin, 

editors. Geology and ore deposits of the Tintic Mining District, 

Utah. USDI Geological Survey Professional Paper 107. US. 

GPO, Washington, DC, U.S.A. 

Lanner, Ronald M. 1977. The eradication of pinyon-juniper woodland. Western Wildlands. Spring: 13-17. 

Lanner, Ronald M. 1981. The Pinon Pine. University of Nevada 

Press, Reno, NV. 208 pp. 

Lindgren, W. and G. F. Loughlin. 1919. Geology and ore deposits of 

the Tintic mining district. USDI Geological Survey Professional 

Paper 107. U.S. GPO, Washington, DC, U.S.A. 

Raymond, R. W. 1873. Statistics of mines and mining in the states 

and territories west of the Rocky Mountains. Fifth Annual Report. Forty-second Congress, Third Session. Ex. Doc No. 210. U.S. 

GPO, Washington, DC, US.A. 

Rogers, G. F. 1982. Then & now. University of Utah Press. Salt Lake 

City, Utah. 

Rogers, G. F., H. E. Malde, and R. M. Turner. 1984. Bibliography of 

repeat photography for evaluating landscape change. University 

of Utah Press, Salt Lake City, Utah, U.S.A. 

Seamons, M. L. 1992. More precious than gold. Community Press, 

Salt Lake City, Utah, U.S.A. United States Department of the 

Interior. 1880. Tenth Census of the United States. U.S. GPO, 

Washington, DC, U.S.A. 

United States Department of the Interior. 1890. Eleventh Census of 

the United States. U.S. GPO, Washington, DC, U.S.A. 

United States Department of the Interior. 1900. Twelfth Census of 

the United States. US. GPO, Washington, DC, U.S.A. 

United States Department of Commerce. 1910. Thirteenth Census 

of the United States. U.S. GPO, Washington, DC, U.S.A. 

Young, J. A. and J. D. Budy. 1979. Historical use of Nevada's pinyonjuniper woodlands. Journal of Forest History (23):112-121. 

Young, J. A. and J. D. Budy. 1986. Energy crisis in 19th century 

Great Basin woodlands. Pages 23-28 in R. L. Everett, compiler. 

Proceedings, Pinyon-Juniper Conference, Reno, Nevada, USDA 

Forest Service Intermountain Forest and Range Experiment 

Station General Technical Report INT-215. US. GPO, Washington, DC, U.S.A. Ogden, Utah, U.S.A. 

133 
Calorimetric Study of the Effects of Water 

and Temperature on the Respiration and 

Growth of Small Burnet and Alfalfa 

Angela R. Jones 

Bruce N. Smith 

Lee D. Hansen 

Stephen B. Monsen 

Richard Stevens 

Abstract-The relative degree of drought tolerance was studied for 

six populations of small burnet CSanguisorba minor), and six cultivars of alfalfa (Medicago sativa) grown in common gardens under 

natural conditions and in the laboratory with different levels of 

moisture. Metabolic heat rate (q) and respiratory rate (RC02) were 

measured weekly on fresh leaf tissue from field-grown plants from 

early April to early August 1997. Both species grew best in early 

spring but remained green and active throughout the summer. 

Small burnet was more drought tolerant than alfalfa. Further 

studies may allow specific selections of populations and cultivars to 

be made for growth on particular sites. 

Desert plants have adapted to dry climates, but differ in 

the degree of adaptation among species and cultivars or 

populations. Plants that better tolerate conditions of low 

water and high temperature stay green longer into a hot 

summer, and can be used effectively in green belts and 

forage projects. Small burnet (Sanguisorba minor) and alfalfa (Medicago sativa) are two such species that grow in the 

Great Basin. Small burnet is a perennial recently introduced 

from Eurasia into Utah for erosion control at altitudes 

between 1,525 and 2,135 m (Welsh and others 1987). Alfalfa 

was also introduced from the Old World, possibly into 

California by the Spanish, and is now one of the most 

important forage crops in the United States (Stechman 

1986; Welsh and others 1987). Both species are tolerant of 

heat and drought, making them candidates for green belts 

and forage projects in dry areas, but each species has 

different cultivars or populations that differ in their degrees 

of tolerance to drought and heat. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Angela R. Jones is a Graduate Student and Bruce N. Smith a Professor in 

the Department of Botany and Range Sciences, and Lee D. Hansen a Professor 

in the Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602. Stephen B. Monsen is a Botanist at the Rocky 

Mountain Research Station, Forest Service, U.S. Department of Agriculture, 

Shrub Sciences Laboratory, Provo, UT 84606. Richard Stevens was a Project 

Leader (retired) with the Utah Division of Wildlife, Great Basin Experiment 

Station, 540 North Main, 32-7, Ephraim, UT 84627. 

Acknowledgments: Funds provided in part through the Federal Aid to 

Wildlife Restoration, Pittman-Robertson Project 82-R. 

134 

Calorimetry can be used to rapidly evaluate the tolerance 

limits of a cultivar, accession, or species because it can 

quantitate the stress response of metabolism. Hansen and 

others (1994) have shown that simultaneous measurements 

of metabolic heat rate (q) and respiratory CO2 rate (RC02) can 

be used to calculate growth rate and substrate carbon 

conversion efficiency as a function of conditions. Predictions 

about relative fitness can be made by comparing the growth 

rates and efficiencies of different plants at specific conditions. Plants can then be selected to match environmental 

conditions at specific sites. Calorimetry offers advantages 

over traditional field studies by saving time and providing 

insight into the mechanism of the stress response. 

In the model developed by Hansen and others (1994), the 

specific growth rate is defined as: 

(Eq. 1) 

whereyp is the average oxidation state ofthe substrate carbon, 

~H02 is a thermodynamic constant equal to -455 kJ mol-I O2 

and ~HB is the total enthalpy change associated with the 

conversion of one mole of substrate carbon into one mole 

of biomass carbon. Assuming that yp is equal to 0 (that is, 

that carbohydrate is the substrate) and that ~HB is a 

constant, the relative specific growth rate (RsG~HB) can be 

calculated from measurements of q and RC02' When q and 

RC02 are measured as functions of environmental variables, 

growth rate can then be calculated as a function of the same 

variables. 

The substrate carbon conversion efficiency (E) can be 

calculated from the same parameters used to calculate the 

relative specific growth rate. The ratio of metabolic heat 

rate to respiratory CO2 rate (q/Rc02 ) is an indicator of 

substrate carbon conversion efficiency. 

q/Rc02 = 455(1 - y/4) - [(£1(1- E)]~HB (Eq.2) 

Substrate carbon conversion efficiency (E) ranges from 0 to <1. 

Val ues of q/RC02 are typically between 300 and 450 kJ mol-I. In 

this range a lower value of q/RC02 may indicate a higher 

efficiency although changes in yp and/or ~HB can also affect 

the ratio. Under conditions where the substrate being 

burned in respiration is carbohydrate (yp = 0), and ~HB is 

endothermic, that is positive, the value of q/Rc02 cannot 

exceed 455 kJ mol-I, but the val ue of q/Rc02 is often observed 

to exceed 455 kJ mol-I. If q/Rc02>455 kJ mol-Ieither the 

substrate being burned is no longer carbohydrate (that is, 

yp has changed to a positive value), or the biomass being 

USDA Forest Service Proceedings RMRS-P-9. 1999 
produced has changed (that is, i1HB has changed to a negative value), or both. Either option indicates that a change in 

the biochemical pathways has occurred, either the substrate 

being burned has changed, or the product biomass composition has changed. 

Arrhenius plots of metabolic heat rate versus reciprocal 

absolute temperature (In(q) vs, T-I ) can be used to describe 

the temperature dependence of q over a temperature range. 

The temperature coefficient, Ilq, is obtained from the slope of 

the Arrhenius plot. Likewise, the temperature coefficient of 

the respiratory CO2 rate, IlC02, is the slope of the Arrhenius 

plot of the respiration rate versus reciprocal temperature 

(In(Rco2) vs. T-I). Ilq and IlC02 provide physiological data on 

the effect of temperature on the metabolism. Differences in 

the temperature dependency of q and Rco2 can be used to 

predict the effects of temperature on the growth of different 

populations or cultivars. 

The purpose of this study is to use respiratory heat and 

CO2 rates to select the most drought and heat tolerant 

populations of small burnet and cultivars of alfalfa. Criddle 

and others (1997) have shown that calorimetry can be used 

to rapidly measure metabolic heat rate and respiration rate 

at different temperatures. 

Methods 

Field Experiment 

Six populations of small burnet were grown in two common gardens maintained by the Utah Division of Natural 

Resources near Ephraim and Nephi, UT. The variety U13 or 

Delar is commercially released while the others were 

grown from imported seed (Moore 1995): B10 (Yugoslavia), 

B28 (Russia), B30 (Spain), B34 (Russia), and B51 (Iran). 

Five cultivars of alfalfa-Henry Mt., Nomad, Ranger, 

Spreader II, and Ladak 65-were grown in plots in the 

garden at Ephraim, UT. Plants in the common gardens grew 

on shallow limestone soils and were not irrigated. One 

cultivar of alfalfa, Magnum, 'was grown % mile from the 

Ephraim common garden in deep soils and was irrigated and 

fertilized. Magnum plants were 3 years old and were Medicago sativa, the others were 2 years old and were hybrids of 

Medicago sativa and Medicago {alcata. 

Young leaf tissue from small burnet was collected once a 

week between April 2 and August 7, 1997, and between 

April 29 and July 10, 1997 for alfalfa. Samples were kept in 

an ice chest or refrigerated until measurements were made. 

Laboratory Experi ment 

Seeds from five of the populations of small burnet, B10, 

B28, B30, B34, and B51, and seven cultivars of alfalfa, 

Henry Mt., Nomad, Ranger, Spreader II, Ladak 65, Magnum, and Yellowhead, were planted in sandy loam on laboratory growth carts. Plants were grown with a 13/11 hour 

light/dark schedule at a constant 21 cC. At approximately 

60 days, plants were subjected to three different watering 

regimes. Plants were watered to field capacity, % field 

capacity, and % field capacity. Metabolic heat rates and 

respiratory CO2 rates were measured between 70 and 77 

days. Measurements were taken on two plants from each 

treatment. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Calorimetry 

Metabolic heat rate and respiratory CO2 rate were measured with a Hart Scientific model 7707 Differential Scanning Calorimeter operated in isothermal mode (Criddle 

and others 1997). Approximately 100 mg fresh weight of 

young leaf tissue was used for each measurement. Respiratory CO2 rates were determined using the method described 

in Criddle and others (1997). After measurement of metabolic heat rate, a small vial with 40 III of 0.4 M NaOR was 

placed into the calorimeter ampule with the tissue. As the 

CO2 and NaOH react in solution, heat is produced and the 

increase in heat rate is proportional to the rate of CO2 

evolution. The heat of reaction for carbonate formation 

(-108.5 kJ mol-I) was used to convert the heat rate into the 

rate of CO2 evolution. 

Results __________ _ 

Small 8 urnet 

Table 1 lists the flowering and growth data for field-grown 

small burnet. U13 and B34 had flowering stems and red 

flowers the earliest (May 13) followed by B30 and B51 which 

had flowering stems and red flowers on May 19, and then 

B10 and B28 which had flowering stems on May 19 and red 

flowers on May 27. U13 had the slowest growth while B10 

and B34 have slow growth early in the season, but growth 

increases in June. B28, B30, and B51 show the greatest 

production, with B51 showing the greatest growth early, 

maintaining good growth longer. 

Both small burnet and alfalfa grow well early in the 

spring. During the first portion of the growing season, 

respiration rate (Rco2) and efficiency (E) are high, that is, 

q/Rco2 is low (table 2). There were no significant differences in respiratory properties between the populations of 

small burnet grown in Nephi and those grown in Ephraim. 

Also, the q and Rco2 values obtained did not change with 

sampling date except a few days following flower maturation. Therefore all data before and after this ontological 

Table 1-Field growth data on small burnet. Early flower is when 

flowering stems first appear, mature flowers appear red. 

Flowering dates on Ephraim plants, growth descriptions 

based on Nephi plants. 

Population Early flower Mature flower Growth 

B51 May 19 May 19 Best growth 

early and late 

B30 May 19 May 19 Good growth early 

slows down in June 

B10 May 19 May 27 Poor growth early 

good late growth 

B28 May 19 May 27 Poor growth early 

good late growth 

B34 May 13 May 13 Poor growth early 

fair late growth 

U13 May 13 May 13 Poorest growth 

early and late 

135 
Table 2-Values for q, RC02, q/Rc02, and RSG~HB for each population of small burnet at 15 and 25°C early in the season (before late Mayor early 

June when a drop in metabolic rates occurred) and late in the season. 

Pop. qat 15° RC02 at 15° q/Rc02 at 15° RSGMiB at 15° qat 25° RCo2 at 25° q/Rc02 at 25° RSGMiB at 25° 

Early in the season 

810 3.5 13.7 273 2.7 

828 3.9 14.3 292 2.6 

830 4.0 15.4 267 3.0 

834 3.7 13.3 298 2.4 

851 4.1 14.8 284 2.7 

U13 3.8 12.6 313 2.0 

Late in the season 

810 2.2 7.8 288 1.3 

828 2.6 7.7 381 0.9 

830 2.6 6.5 412 0.4 

834 2.6 6.7 401 0.4 

851 2.6 7.1 381 0.6 

U13 1.7 3.8 510 0.0 

event were averaged to obtain two data points, one describing heat and CO2 rates before the maturation event and one 

after. A few days after flowering, in late Mayor early June, 

a decrease in metabolic rate occurs (fig. 1) and q/RC02 

increases (table 2). Not all populations flowered at the 

same time nor was the time-course of metabolism identical 

for the populations (table 2). The decrease in metabolic 

activity occurred during the week following May 27 for B51, 

B30, and B28, but not until the week following June 2 for 

BI0 and B34, and the week following June 9 for U13. 

While a change from 15 to 25°C increased the respiration rate (Rcoz) by about a factor of 2, efficiency decreased 

(see q/Rcoz values in table 2). That is, more of the available 

18 

16 

c 14 

0 

+= 

CO 

'- 12 

a. 

en 

C1> 

a: 10 

8 

6 

8.9 26.0 361 2.9 

9.8 27.1 365 2.6 

10.0 30.4 348 3.8 

9.7 26.7 377 2.4 

10.3 28.4 374 2.7 

9.4 25.6 380 2.2 

5.8 14.4 376 0.7 

6.8 14.7 506 -0.1 

6.2 12.4 525 -0.5 

6.2 14.0 467 0.1 

7.1 15.2 481 -0.2 

4.5 13.5 442 1.7 

Table 3-Temperature coefficient of q and RC02 for 

different populations of small burnet. 

Population J.lq J.lC02 

810 8.0 7.2 

851 8.1 6.2 

U13 8.1 5.9 

830 8.0 5.6 

834 7.8 5.5 

828 7.9 5.4 

metabolic energy was lost as heat and was thus unavailable 

for growth at the higher temperature. 

The temperature coefficient for heat rate (Ilq) was essentially the same for all populations, while the coefficient for 

respiration rate (IlC02) was much higher for BI0 and B51 

than for other populations (table 3). 

In the laboratory drought experiment differences in metabolism were observed between the low, medium, and high 

watering treatments. As shown in table 4, heat rate, respiration rate, efficiency, and predicted growth at 15°C are all 

negatively correlated with increasing levels of water. Small 

burnet did better at 1fs offield capacity than at higher levels 

of watering. 

Table 4-Laboratory drought experiment for small burnet. Data for all populations 

pooled. High water treatment is field capacity, medium water treatment 

0 10 20 30 40 is % field capacity, and low water treatment is % field capacity. 

Days 

Figure 1-Schematic of the metabolic change occurring 

in small burnet during a few days in late Mayor early 

June 1997. Respiration or RC02 in pmol mg-1

s- 1 versus 

time in days. 

136 

Water 

treatment 

Low 

Med 

High 

qat 15° RC02 at 15° q/RC02 at 15° RSGMiB at 15° 

(jJWmg-1) (pmol mg-1s-1) (kJ mol-1) (jJWmg-1) 

2.9 9.8 305 1.6 

2.4 7.0 373 0.8 

1.9 4.9 443 0.4 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 5-Average values for q, RC02, q/RC02' and RSGLlHs for cultivars of alfalfa at 15 and 25 °e. 

Cultivars qat 15° RC02 at 15° q/Rc02 at 15° RSGMiB at 15° qat 25° RCo2 at 25° q/Rc02 at 25° RSGMiB at 25° 

Henry Mt. 4.0 11.5 425 0.9 

Nomad 4.4 12.0 411 0.6 

Magnum 6.4 18.5 332 2.2 

Ranger 4.6 12.7 363 1.2 

Spreader II 4.8 14.9 333 2.0 

Ladak 65 4.6 13.2 367 1.2 

Alfalfa 

All alfalfa cultivars had a QlO for respiration (RC02) greater 

than 2 (table 5). Efficiency (q/Rc02 ) was better at 15 than 

25 °e for four of the cultivars but showed little difference 

with temperature for Henry Mt. a-nd Nomad. Predicted 

growth (RsGL1HB) was better at 15 °e for all cultivars, except 

for Magnum. 

The temperature coefficient for heat rate (Ilq), while more 

variable for alfalfa cultivars than for small burnet populations, was essentially the same for all cultivars (table 6). By 

contrast the temperature coefficient for respiration (IlC02) 

showed differences among the cultivars. 

Pooled data for all cultivars of alfalfa from the laboratory 

drought experiment (table 7) showed no trends with watering treatment. 

Discussion --------------------------------- The spring and summer of 1997 were unusually wet and 

cool. It proved to be a poor year to try to assess the effects of 

drought in the field. This study should be repeated over 

several seasons to gain a true understanding of response in 

the field to temperature and soil moisture of populations of 

small burnet and cultivars of alfalfa. However, some conclusions can be drawn from this small beginning. 

While both small burnet and alfalfa remain green and 

active all summer, they both .grow best in the cool, moist 

spring months. The decrease in metabolism and growth a 

few days after flowering (fig. 1) may signal seed set and 

represent a shift from active growth to partial dormancy in 

order to survive the usual dry, hot summer months in the 

Great Basin. The strategy may be to conserve energy during 

the harsh summer months and grow more rapidly during 

better, even though cooler, conditions. This can be seen 

best with small burnet (table 2). The QlO for respiration 

remains the same during the shift from early to late season, 

but the respiration rate decreases and q/RC02 increases. 

These changes may indicate a shift in efficiency or in biochemical pathways, either in the respiratory substrate, or 

Table 6-Temperature coefficients of q and RC02 for 

cultivars of alfalfa. 

Cultivar Ilq IlC02 

Nomad 8.1 8.1 

Magnum 8.1 7.0 

Ranger 8.7 7.0 

Henry Mt. 8.5 6.5 

Ladak 65 8.1 6.3 

Spreader" 7.9 5.3 

USDA Forest Service Proceedings RMRS-P-9. 1999 

10.7 23.2 433 0.4 

11.4 26.5 435 0.7 

16.6 43.3 395 3.1 

11.5 25.5 470 0.1 

12.1 29.5 395 1.5 

11.8 27.8 458 0.9 

Table 7-Laboratory drought experiment for alfalfa. Data for all cultivars pooled. 

Water 

High water treatment is field capacity, medium water treatment is % 

field capacity, and low water treatment is Y3 field capacity. 

qat 15° RC02 at 15° q/Rc02 at 15° RSG~B at 15° 

treatment (JlWmg-1) (pmol mg-1s-1) (kJ mol-1) (JlWmg-1) 

Low 3.0 11.0 395 2.0 

Med 2.6 6.2 453 0.3 

High 3.0 9.0 357 1.1 

the composition of the biomass being produced. In growing 

tissues, rates of catabolism are known to depend on rates of 

anabolism. The story is similar for alfalfa (table 5). 

At 15 °e the populations of small burnet (table 2) ranked 

from highest predicted growth rate (RscL1HB) to lowest were: 

B30>B51=B10>B28>B34>U13. 

The alfalfa cultivars similarly ranked (table 5) by RSGL1HB 

were: 

Magnum>Spreader Il>Ranger=Ladak65>Henry Mt.>Nomad. 

Conclusions _________ _ 

Small burnet and alfalfa have higher relative specific 

growth rates and higher efficiency (that is, lower values of 

q/Rc02) at 15 than at 25 °e. Thus the rate of energy storage 

in structural biomass is faster at lower temperatures. 

Populations of small burnet and cultivars of alfalfa that 

show a decrease in metabolic rate later in the season will 

grow slowly but remain green longer. 

Small burnet seems to be more drought-resistant than 

alfalfa. 

References --------------------------------- Criddle, R S.; Smith,B. N.; Hansen, L. D.1997. A Respiration Based 

Description of Plant Growth Rate Responses to Temperature. 

Planta. 201: 441-445. 

Hansen, L. D.; Hopkin, M. S.; Rank, D. R; Anekonda, T. S.; 

Breidenbach, R W.; Criddle, R S. 1994. The Relation Between 

Plant Growth and Respiration: A Thermodynamic Model. Planta. 

194: 77-85. 

Moore, K. D. 1995. Effects of Seed Size on Germination and Emergence of Burnet (Sanguisorba) Scop. (Rosaceae) and Variation in 

Drought Tolerance Within and Among Ecotypes of Small Burnet 

(Sanguisorba minor) Scop. (Rosaceae). Master of Science Thesis. 

Brigham Young University. 76 p. 

Stechman, J. V. 1986. Common Western Range Plants: Their 

Fundamental Structure, Growth, Value and Management. 3rd 

ed. California Polytechnic State University Foundation. 

Welsh, S. L.; Atwood, N. D.; Goodrich, S.; Higgins, L. C. 1987. A 

Utah Flora: Great Basin Naturalist Memoir #9. Brigham Young 

University Press. 

137 
Changes in Plant Composition within a 

Pinyon-Juniper Woodland 

Dennis D. Austin 

Ahstract-Vegetal composition and photo comparisons were determined during 1974,1984, and 1997 on seven permanent 50 m2 plots 

within a mature pinyon-juniper community in northeastern Utah. 

Data and photo comparisons showed few changes over 23 years. 

Within the Intermountain Region, pinyon-juniper habitat 

provides a major proportion of big game and livestock winter 

ranges. While it is clearly recognized that available forage of 

shrubs and other species declines as density and cover of 

pinyon-juniper increases, few longitudinal studies have defined the rate of change, particularly in mature woodlands. 

This paper presents data and supporting photographs defining the slow rate of successional change. 

Methods __________ _ 

Data were collected in the exact methodology during 1974, 

1984, and 1997 (Austin 1987), with the only exception that 

data collected in 1997 were taken only from selected plots 

with photo points. 

Each plot measured 5.5 x 9.1 m and was marked by steel 

reinforcement rods on all corners. Plot boundaries were 

defined by connecting the four corners with a string or tape. 

All perennial plant species within the plot were counted and 

recorded by species. To assure that individual plants were 

not missed on these large plots, a separate search was made 

for every perennial species, previously identified in the area. 

Mature trees were defined with height greater than 120 cm. 

Annual plants were not considered in this report. 

Results and Discussion 

Changes in plant community composition were not detected during the 23 year interval (table 1). The number of 

mature U tahj uni per (J unipe r osteosperma) and pinyon pine 

(Pinus edulis) were unchanged. A single juvenile Utah 

juniper became established but later died. An additional 

four juvenile pinyon pines were recorded suggesting slow 

change towards pinyon dominance. A numerical increase in 

the number oflow sagebrush (Artemisia arbuscula) was due 

to a number of small seedlings established within the last 

one to three years. The number of dead shrub skeletons 

declined numerically during the three periods. The number 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Dennis D. Austin is a wildlife biologist with the Division of Wildlife 

Resources and is associated with the Department of Rangeland Resources, 

Utah State University, Logan, UT 84322-8430. 

138 

Table 1-Number of plants per seven permanent, 50 m2 plots. 

Species Year 

Trees 1974 1984 1997 

Juniperus osteosperma - mature 22 22 22 

Juniperus osteosperma - juvenile 16 17 16 

Pinus edulis - mature 6 6 6 

Pinus edulis - juvenile 2 6 6 

Shrubs 

Artemisia arbuscula 52 63 86 

Artemisia tridentata 13 11 15 

Ephedra viridis 76 74 80 

Gutierrezia sarathrae 56 77 68 

Other shrubs 9 10 14 

Shrubs-Dead skeletons 84 67 34 

Perennial Grasses 

Poa secunda 8 19 6 

Sitanion hystrix 13 8 11 

Perennial Forbs 

Aster arenosus 249 286 193 

Cryptantha spp. 110 99 40 

Erysimum spp. 88 48 81 

Gilia congesta 34 19 9 

Opuntia spp. 5,366 4,468 4,444 

Penstemen spp. 35 99 110 

Petradoria pumila 259 244 241 

Physaria chambersii 14 25 8 

Sisymbrium linifolium 215 154 104 

Townsendia incana 14 6 4 

Other Forbs 15 22 18 

of perennial grass and forb species varied by individual 

species during the three measurement periods, but no distinct changes in population by species could be defined. 

Photo points confirmed no measurable changes in the 

plant community. Figures 1-6 are representative of the 

woodland during 1974, 1984, and 1997. All photos were 

taken between June 15 and July 5. Figures 1A and 2A were 

taken in 1974 and compared with photos taken in 1997, 

figures 1B and 2B, respectively. Likewise, figures 3A, 4A, 

5A, and 6A were taken in 1984 and compared with photos 

taken in 1997. 

A few notes: Mter 23 years all reinforcement rods marking 

the plot corners, and after 13 years all reinforcement rods 

marking the photo positions were intact. The photo points 

established in 1974 were not marked by reinforcement rods. 

Comparing figures 1A and 1B, note the increase in size of the 

Ephedra (Ephedra viridis) in the center of the photos. 

Increase or decrease in size of individual Ephedra plants or 

clumps was variable. Comparing figures 2A and 2B, note the 

dead sagebrush skeleton next to the rock in the lower left 

corner in 1997, but absent in 1974. Establishment and death 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Figure 1A-1974 plot 19. 

Figure 2A-1974 plot 20. 

Figure 3A-1984 plot 21. 

of individual sagebrush plants was common during the 

periods. Comparing figures 3A and 3B, note the consistency 

in density ofthe small perennial desert aster (Aster arenosus). 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Figure 18-1997 plot 19. 

Figure 28-1997 plot 20. 

Figure 38-1997 plot 21. 

Although found on few plots, once established this species, 

like most perennial forb species, persisted. Comparing figures 4A and 4B, note the fire scarred stump in the center of 

139 
Figure 4A-1984 plot 8. 

Figure 5A-1984 plot 26. 

Figure 6A-1984 plot 28. 

the photos. Very little change or decomposition for dead 

limbs oftrees was found. Comparing figures 6A and 6B, note 

the increase in the size of diameter of the pinyon on the left. 

Growth rates of height and diameter for pinyon pine were 

about 1.0 em/year. 

140 

Figure 48-1997 plot 8. 

Figure 58-1997 plot 26. 

Figure 68-1997 plot 28. 

Reference --------------------------------- Austin, D. D. 1987. Plant community changes within a mature 

pinyon-juniper woodland. Great Basin Naturalist. 47: 96-99. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Soil Seed Banking in Pinyon-Juniper Areas 

With Differing Levels of Tree Cover, 

Understory Density and Composition 

Clare L. Poulsen 

Scott C. Walker 

Richard Stevens 

Abstract-With removal of competitive pinyon-juniper overstory, 

endemic vegetation is released allowing germinating seed within 

the soil seed bank to establish. Density of seedlings is closely 

correlated with the density and composition of the understory 

community and tree cover. Considerable effort and costs are generally put into seeding areas following tree removal. If the amount and 

type of viable seed in the soil could be accurately estimated, seeding 

costs and effort could be adjusted. Studies were conducted on soil 

seed banking at two pinyon-juniper sites in central Utah. At each 

site, areas were studied ranging from closed pinyon-juniper stands 

with minimal understory to open stands with excellent understory 

communities. Seed density and composition within the soil varied 

with tree cover and understory community differences. 

As pinyon -j uni per stands mature, canopy cover increases, 

and a decrease in the understory community density and 

composition occurs. The correlation between decreasing 

understory species and increasing tree canopy cover on the 

soil seed bank is poorly understood. By quantifying composition and viability of seeds existing in the soil seed bank, more 

effective treatment of pinyon-juniper stands could occur. 

Studies have looked at various influences and aspects of 

the soil seed bank; fire (Valbuena and Trabaud 1995); 

grazing (Kinucan and Smeins 1992); grasslands (Cofin and 

Lauenroth 1989); forest lands (Chambers and others 1991); 

and cultivated fields (Dessaint and others 1991). These 

studies show that a soil seed bank with sufficient quantity 

and viability of seeds can provide the needed seed reserves 

for community regeneration. However, it has not been identified how tree canopy cover affects the number of species 

and volume of viable seed in the soil seed bank. This study 

was established to identify the density of seeds in a soil seed 

bank at different percent canopy cover of pinyon-juniper. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Clare L. Poulsen, Scott C. Walker are Research Biologists and Richard 

Stevens was Project Leader (retired), Utah Division of Wildlife, 540 N. Main 

32-7, Ephraim, UT 84627. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Methods _________ _ 

Two study sites were on Utah Division of Wildlife land 

6 miles north of Ephraim, UT. The area is 1,800 min elevation 

with Amtoft flaggy loam and Quaker silty clay loam soils. 

Annual precipitation for the area is 32.1 cm. The sites had 

an average slope of 18 percent. The southern site has a west 

aspect and the northern site has a north aspect. Each study 

site contained three areas with distinctive pinyon-juniper 

canopy cover classes; (1) >60 percent tree canopy cover with 

depleted understory community; (2) >30 percent to <60 

percent tree canopy cover with moderately depleted understory community; and (3) <30 percent tree canopy cover with 

nondepleted understory community present. These three 

cover class areas were adjacent to each another with similar 

slope, soils, and exposure. 

Within each canopy cover class area on each site one 25 x 

25 m plot was identified. Within each plot five 25 m long 

transects were randomly established. At every meter mark 

along each transect one 0.25 m2 quadrat was placed. Within 

each quadrat species density and cover was determined for 

grasses, forbs, and shrubs. Five soil samples were randomly 

obtained along each transect for a total of 25 samples per 

plot. Each soil sample consisted ofthe removal of all soil and 

material from a 7 x 7 x 2.5 cm deep area (Cabin 1996 and 

Garcia 1995). Soil samples were washed through a series of 

three sieves (4 mm, 2 mm, and 250 Jlm) (Gross 1990). Sieved 

soil samples were dried for 24 hours in a heated seed 

germinator. Sieved samples were ocularlyinspected using a 

lOx microscope. Filled seed was then removed and identified to species or group and recorded. Every tree in each plot 

was measured for height and crown diameter. From the 

diameter, the area was calculated for each tree. Percent tree 

canopy cover per plot was calculated by total area of all 

trees in a plot divided by total plot area. 

Understory and seed bank species were placed in groups 

by life form to simplify the analysis. The understory composition, vegetation life form mean density, and seed density 

was analyzed using a one-way analysis of variance (ANOV A). 

Life form groups were analyzed separately to ensure that the 

outcome reflected changes in composition not overall abundance. The understory composition was collected by using a 

modified Daubenmire (1959) cover class. The seven classes 

are: (1) 0.01 to 1 percent, (2) 1.1 to 5 percent, (3) 5.1 to 25 

percent, (4) 25.1 to 50 percent, (5) 50.1 to 75 percent, (6) 75.1 to 

95 percent, (7) 95.1 to 100 percent. Cover class midpoints of 

0.5,3,15,37.5,62.5,85, and 97.5 were used to calculate the 

mean cover. Results for vegetation life form per ha and seed 

density per m2 were calculated and analyzed. 

141 
Results 

J... 100 Q) 

> 90 0 

() 

J... 80 

Q) 

a. 70 

c: 60 ::l 

" 

c: 50 

0 

~ 40 

c: 

a. 30 +of 

c: 20 

Q) 

(.) 10 J... 

Q) 

a. 0 

depleted mod. depleted nondepleted 

• Percent Cover Density per ha 

Figure 1-Percent pinyon-juniper cover and numbers of trees associated 

with the three understory vegetation classes. 

1000 

ca 

800 J: 

J... 

Q) 

a. 

600 ~ 

== t/) 

c: 

Q) 400 C 

Q) 

Q) 

200 ~ 

0 

----------------------------------- understory vegetation was highest. Shrub, grass, and forb 

cover was significantly higher with fewer trees present. 

Percent tree cover and number oflive trees per ha for the 

depleted, moderately depleted, and nondepleted understories were 69 percent cover with 864 trees per ha; 51 percent 

cover with 576 trees per ha; and 8 percent cover with 128 

trees per ha respectively (fig. 1). The understory percent 

cover was significantly (P < 0.05) higher in the nondepleted 

site as compared to the depleted site (fig. 2). Litter and rock 

cover was lower in the areas w here the canopy was open and 

In the depleted understory 31 species were present. The 

most common species were annual and perennial forbs. Both 

moderately depleted and nondepleted understory had 27 

species each. The vegetation shifted from annual and perennial forbs in the depleted understory to perennial grasses 

and shrubs in the moderately depleted and nondepleted 

understories (fig. 3). The most common perennial forbs 

present with a high pinyon -j uni per canopy were phlox (Phlox 

142 

J... 

Q) 

> 0 

(J 

+of 

c: 

Q) 

(.) 

J... 

Q) 

a. 

40 

A 

30 

20 

10 

o 

depleted 

• Shrubs 

D Rock 

mod. depleted nondepleted 

Forb/grass D Litter 

• Bare ground 

Figure 2-Percent cover of understory composition in three understory 

vegetation classes. *Columns for same understory component within a 

series with same letter are not significantly different (P < 0.05). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
ctI 7000 .c 

..... 

ci 6000 '-CI) 

c. 5000 

>-

'ii) - 4000 

c: 

CI) 3000 0 

-c: 2000 ctI 

a:: 

c: 1000 ctI 

CI) 0 ::E depleted mod. depleted nondepleted 

• Annual Forbs • Perennial Forbs D Annual Grasses 

Perennial Grasses • Shrubs 

Figure 3-Mean plant density of understory species by life form per 0.1 ha. 

*Columns for same life form within a series with same letter are not 

significantly different (P < 0.05). 

spp.), goldenweed (Haplopappus spp.), and cryptantha 

(Cry ptantha spp.). With a more open tree canopy, astragalus 

(Astragalus spp.), globe mallow (Sphaeralcea coccinea), and 

primrose (Oenothera spp.) were the prominent perennial 

forbs. With a closed canopy cover broom snakeweed 

(Gutierrezia sarothrae) was the common shrub. The shrub 

component shifted to low rabbitbrush (Chrysothamnus viscidi{lorus), shadscale (A trip lex confertifolia), and big sagebrush (Artemisia tridentata) with a more open tree canopy. 

Seed density in the soil seed bank was significantly greater 

in the moderately depleted and nondepleted understory 

compared to the depleted understory (fig. 4). The greatest 

density of seeds was in the moderately depleted understory 

with 7,240 seeds per m2 (table 1). The depleted and 

nondepleted areas had 3,884 and 6,236 seeds per m2 respectively. Seeds for 15, 12, and 14 species were found in the soil 

seed bank for the depleted, moderately depleted, and nondepleted communities respectively. The greatest number of 

grass seeds was in the nondepleted understory (fig. 4 and 

table 1). Perennial forbs, annual forbs, and tree seeds were 

the most frequent in the moderately depleted community. 

Density of understory vegetation with number and seeds 

found in the soil was highly correlated with an R2 = 0.905 

(fig. 5). 

6000~------------~~~--------~--------------~ 

N 

E 5000+-------------~ 

'-CI) 

~ 4000+-------------~­ CI) 

CI) 

~ 3000 

o 

'-CI) 

~ 2000 ~ 

z 

1000 

o 

• Annual Forbs 

mod. depleted 

Perennial Forbs D Annual Grasses 

Perennial Grasses • Trees 

Figure 4-Extrapolated total number of seeds in the soil seed bank by life 

form per m2• *Columns for same life form within a series with same letter 

are not significantly different (P < 0.05). 

USDA Forest Service Proceedings RMRS-P-9. 1999 143 
144 

Table 1-Number of species and number of seeds per species in the soil seed bank by life form 

and understory vegetation class. Percent of total is included in parentheses. 

Understory vegetation class 

Life form Depleted Mod. depleted Nondepleted 

Life form class - - - - - - - Number of species (percent)- - - - - - -

Annual forbs AF 6 (40) 3 (25) 4 (29) 

Perennial forbs PF 1 (6) 2 (17) 2 (14) 

Annual grasses AG 1 (6) 1 (8) 1 (7) 

Perennial grasses PG 5 (33) 4 (33) 6 (43) 

Woody W 2 (13) 2 (17) 1 (7) 

Total 15 12 14 

Individual species present - - - - - - - - Number of seeds (percent)- - - - - - - -

Bur buttercup AF 1,892 (49) 5,352 (74) 3,364 (54) 

Mustard species AF 1,420 (37) 340 (5) 976 (16) 

Composite species PF 0 224 (3) 4 (0.1) 

Cryptantha PF 112 (3) 12 (0.2) 4 (0.1) 

Cheatgrass AG 280 (7) 496 (7) 1,212 (19) 

Bluebunch wheatgrass PG 16 (0.4) 296 (4) 352 (6) 

Indian ricegrass PG 40 (1 ) 20 (0.3) 68 (1) 

Needle-and-thread PG 0 0 4 (0.1) 

Sanberg bluegrass PG 4 (0.1 ) 308 (4) 168 (3) 

Squirreltail PG 12 (0.3) 0 4 (0.1) 

Western wheatgrass PG 0 16 (0.2) 16 (0.3) 

Juniper W 72 (2) 168 (2) 48 (0.8) 

Pinyon W 16 (0.4) 4 (0.1) 0 

Other species 20 (5) 4 (0.1) 16 (0.3) 

Total 3,884 7,240 6,236 

6000 

+ 

5000 

C\I 

E 

'-

Cl) 4000 D. 

"'C 

;;;rV V + 

/" 

V 

Cl) 

Cl) 

en 3000 ~ 

0 

/ 

V + 

/" 

V '-

Cl) 

.c 2000 

E 

::J 

Z 

1000 

/ V 

./ V 

7 V 

/V 

V+ , 

W# o 

o 1000 2000 3000 4000 5000 6000 7000 

Mean Plant Density per 0.1 ha 

Figure 5-Understory species density per 0.1 ha and number of seeds per m2 in the soil seed 

bank regression (R2 = 0.902). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Conclusions ------------------------------- A direct correlation was found between pinyon-juniper 

canopy cover, density and composition of understory vegetation, and number of seeds in the soil seed bank. As tree 

cover increased, the understory vegetation and number of 

seeds in the soil seed bank decreases. Further research is 

needed to look more closely into the correlation between the 

canopy cover, understory vegetation and soil seed bank. 

Refinements are also needed in techniques to reduce the 

time requirements to separate soil and seed. As work continues in this area, the understanding of the correlation 

between tree canopy cover and soil seed bank will allow the 

use of more effective seed mixes. Seeding rates and cost of 

seeding should decrease with increasing abundance of seed 

in the soil seed bank. 

Acknowledgments 

Funds were provided through Federal Aid on wildlife 

restoration project W-82-R, project 3 and Rocky Mountain 

Research Station, Forest Service, Provo, UT. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

References __________________ __ 

Cabin, R J. 1996. Genetic comparisons of seed bank and seedling 

populations of a perennial desert mustard, Lesquerella fendleri. 

Evolution. 500: 1830-1842. 

Chambers, J. C.; MacMahon, J. A.; Hafner, J. H. 1991. Seed 

entrapment in alpine ecosystem: effects of soil particle size and 

diaspore morphology. Ecology. 72:1668-1678. 

Cofin, D. P.; Lauenroth, W. K. 1989. Spatial and temporal variation 

in the seed bank of semiarid grassland. American Journal of 

Botany. 76: 53-59. 

Dessaint, F.; Chadeuf, R; Barralis, G. 1991. Spatial pattern analysis of weed seeds in the cultivated soil seed bank. Journal of 

Applied Ecology. 28: 721-730. 

Garcia, M. A. 1995. Relationships between weed community and 

soil seed bank in a tropical agroecosystem. Agri. Eco. And Envrio. 

50: 139-146. 

Gross, K. L. 1990. A comparison of methods for estimating seed 

numbers in the soil. Journal of Ecology. 78: 1079-1093. 

Kinucan, R J.; Smeins, F. E. 1992. Soil seed bank of a semiarid 

Texas grassland under three long-term (36-years) grazing regimes. American Midland Naturalist. 128: 11-21. 

Valbuena, L.; L. Trabaud. 1995. Comparison between the soil seed 

banks of a burnt and unburnt Quercus pyrenaica Willd. Forest. 

Vegetatio. 119: 81-90. 

145 
Distribution of Pinyon-Juniper in the 

Western United States 

John E. Mitchell 

Thomas C. Roberts, Jr. 

Abstract-The extent of pinyon-juniper woodlands in the Western 

United States, as determined from advanced very high resolution 

radiometer (A VHRR) data, has been appraised at approximately 

55.6 million acres. There is presently no complete national inventory to which this total can be compared; however, Forest Service 

plot-based estimates and independent GAP predictions are consistent with the A VHRR acreage in Utah where adequate inventory 

data exist. An assessment by the Bureau of Land Management 

has yielded higher pinyon-juniper coverage for their own lands 

than that derived from A VHRR data. Spatial discrepancies remain 

between the AVHRR and GAP coverages, however. The importance of algorithms in classifying remotely sensed data is noted. 

The Government Performance and Results Act (GPRA) 

of 1993 requires all Federal agencies, including USDA 

Forest Service and USDI Bureau of Land Management 

(BLM), to prepare recurring strategic plans. In order to 

carry out any strategic plan, agencies must have an adequate understanding of the conditions of lands under 

their jurisdiction. National assessments are used to provide the information needed for understanding the rangeland situation in the United States (Joyce 1989). Included in 

most assessments for land management agencies are estimations ofthe extent of and shifts in major rangeland cover 

types, including pinyon-juniper. In this paper, reference to 

pinyon-juniper includes both pinyon-juniper and juniper 

woodlands. 

Given the relative disparities among previous appraisals 

of pinyon-juniper coverage in the Western United States 

(West and others 1975, USDA Forest Service 1989), we 

needed a better estimate of its distribution to support 

GPRA strategic plans due in the years 2000 and 2003. To do 

so, we used several data sources, including reports from 

Forest Inventory and Analysis (FIA) surveys, two different 

estimation methods utilizing advanced very high resolution 

radiometer (A VHRR) data, and GAP data to evaluate one 

AVHRR estimator of nationwide pinyon-juniper distribution. In addition, we compared these estimates to pinyonjuniper acreages provided by BLM for their lands. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

John E. Mitchell is Rangeland Scientist, USDA Forest Service, Rocky 

Mountain Research Station, Fort Collins, CO 80524. Thomas C. Roberts, Jr., 

is Range Conservationist, USDI Bureau of Land Management, Washington, 

DC 20240. 

146 

Methods 

We used a digitized forest type map, developed from 

AVHRR data by the Forest Service's Southern Forest Experiment Station in 1992, as a baseline estimator to assess 

the extent of pinyon-juniper woodlands, by Federal ownership categories, in the Western United States (Powell and 

others 1994). This classification (USFS-AVHRR) differed 

from an earlier one produced by U.S. Geological Survey 

(USGS-AVHRR; Loveland and others 1991) in three ways: 

• It combined A VHRR and Landsat TM classifications to 

create a "forest density" map that filtered out non-forest 

pixels. 

• It used thermal Landsat bands. The USGS classification used only composite maximum greenness timeseries images to separate vegetation types-a process 

which may not have been effective in arid environments. 

• It was validated by FIA plot-based data. 

Using ARC/INFO, we partitioned an Albers (equal area) 

projection of the USFS-A VHRR pinyon-juniper distribution map by Forest Service, BLM, other Federal, and nonfederal land ownership, and calculated the acreage in each 

category. 

The Forest Service estimations for pinyon-juniper coverage, by state, were compared with FIA statistics for Utah 

and Nevada, where extensive FIA plot-based inventory 

data exist (O'Brien and Woudenberg, this proceedings). 

Although FIA state-level estimates include all land ownerships within the Intermountain region, for the most part 

National Forest Systems (NFS) provided the data for NFS 

lands. Data for forests and woodlands not on NFS lands, 

including most BLM lands, were collected by FlA. In 1991, 

FIA carried out a statewide inventory of all forest lands 

across all ownerships in Utah, including reserved (O'Brien 

1999). 

We also compared estimates ofpinyon-juniper abundance 

on BLM lands, by state, with acreages reported by USDI 

Bureau of Land Management (1993). 

Finally, we were interested in ascertaining how similar 

the USFS-A VHRR approximation for Utah was to the coverage of pinyon-juniper from the vegetation layer in the Utah 

GAP program (Edwards and others 1995). The Utah GAP 

program followed a complex vegetation classification system 

that used Landsat TM imagery at 30-m pixel resolution for 

a base map, but was modified by visual photo interpretation 

of aerial photography and digitizing of existing vegetation 

maps (Scott and others 1993). Thus, the two protocols would 

be based upon a substantially different pixel size, l-km for 

USFS-A VHRR and 30-m for the GAP analysis. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
• Pinyon-juniper 

1992 AVHRR data 

Figure 1-Distribution of pinyon-juniper woodland in the western United States (from Powell and others 1994). 

Results __________ _ 

The Forest Service AVHRR estimate of national pinyonjuniper coverage is portrayed in figure 1 and is presented 

numerically in table 1 by state and land ownership. The 

five states of Nevada, Utah, Colorado, Arizona and New 

Mexico account for 46.3 million acres or about 83 percent of 

all U.S. lands dominated by pinyon and/or juniper. We 

estimate the total U.S. area occupied by pinyon-juniper to be 

55.6 million acres. 

Forest Inventory and Analysis plot data summarized in 

this document report that Nevada has 8.839 million acres 

of pinyon-juniper woodland with a standard error of 

187,300 acres (O'Brien and Woudenberg, this proceedings). 

Likewise, Utah is estimated to have 9.149 million acres of 

pinyon-juniper woodland with a standard error of 279,500 

acres. The AVHRR estimate for Utah of9.439 million acres 

shown in table 1 is contained within an 80 percent confidence interval for the FIA estimate. For Nevada, the A VHRR 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Table 1-Area of pinyon-juniper woodlands, by state and ownership, 

for 10 western states. From a Forest Service classification 

of AVHRR data (Powell and others 1994). 

Acres {Thousands} 

State USFS BLM Other Fed Nonfederal All lands 

Ariz. 3,634 964 3,322 1,708 9,628 

Calif. 3,179 793 435 494 4,901 

Colo. 2,248 1,827 500 2,021 6,596 

Idaho 828 594 123 187 1,732 

Nev. 2,754 4,635 414 303 8,106 

N.M. 4,276 1,459 2,184 4,642 12,561 

Ore. 350 134 117 186 787 

Texas 0 0 85 1,562 1,647 

Utah 3,696 4,064 551 1,128 9,439 

Wyo. 125 12 0 66 203 

Total 21,090 14,482 7,731 12,297 55,600 

147 
148 

Table 2-Area of "woodlands" on 

BLM land by state for nine 

western states as reported 

by USDI Bureau of Land 

Management (1993). 

State Acres (Thousands) 

Arizona 

California 

Colorado 

Idaho 

Nevada 

New Mexico 

Oregon 

Utah 

Wyoming 

Total 

1,240 

387 

3,534 

385 

6,210 

1,721 

286 

6,418 

207 

-20,400 

; "H . .. ' .. 

estimate of 8.106 million acres is not within the 80 percent 

confidence interval of 8.600 million acres to 9.079 million 

acres derived from FIA data (O'Brien and Woudenberg 

1999) (table 1). 

Table 2 portrays area of pinyon-juniper for BLM lands 

alone, based upon surveys from USDI Bureau of Land 

Management (1993). The BLM acreages greatly exceed the 

A VHRR estimates for lands under the jurisdiction of BLM 

except for California, Idaho and New Mexico (table 1). The 

largest dissimilarities are for Utah, Colorado "and Nevada. 

One explanation for the somewhat high BLM estimates 

for Utah and Colorado would be their inclusion of oakmountain mahogany woodlands within the woodland category (Kuchler 1964). 

A comparison of the two classifications of A VHRR data 

for the extent of pinyon-juniper in the state of Nevada is a 

pertinent example of how much variation can ensue from 

two algorithms that process the same raw data. The 1990 

USGS protocol detected a total of 2.4 million acres of 

"western woodland" in Nevada, of which 319,000 acres was 

classified as pinyon-juniper woodland (fig. 2). The 1992 FS 

1990 A VHRR data 

• Western Woodlands 

(Pinyon-juniper) 

II Western Coniferous 

Forest (Ponderosa pine) 

D Western Mixed Forest 

(mixed aspen-conifer) 

Figure 2-Distribution of pinyon-juniper woodland in Nevada, derived from a U.S. Geological Survey 

algorithm of AVHRR data (see Loveland and others 1991). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
classification distinguished 8.1 million acres of pinyonjuniper woodland in Nevada, an estimate much closer to the 

8.8 million acres obtained from FIA plot data (O'Brien and 

Woudenberg, this proceedings) (fig. 3). 

The differences between the 1990 USGS-A VHRR and 

USFS-A VHRR estimates of pinyon-juniper acreages in 

Nevada can be visualized by examining a smaller area 

within the state. We arbitrarily selected an area just inside 

Nevada's border with Utah, primarily in White Pine and 

Lincoln Counties, to compare the visual effect of the two 

classifications. The results are obvious and profound (fig. 4 

and 5). 

The assessment for pinyon-juniper coverage in the state 

of Utah comparing USFS-A VHRR and GAP analysis is 

revealing. The two estimates for total cover are extremely 

close, 9.439 million acres to 9.596 million acres, respectively. 

Nonetheless, the spatial distributions are different in both 

locale and density (fig. 6 and 7). We had expected the larger 

pixel size of the USFS-AVHRR map to result in a less 

fragmented portrayal of pinyon-juniper, but the opposite 

actually occurred. The indication of differences in locale can 

be seen by comparing stand distributions using county lines, 

particularly in the south-central part of the state. 

To quantify this apparent lack of consensus between the 

USFS-A VHRR and GAP analysis maps, we tested for overlap of the pinyon and/or juniper polygons in the ARCIINFO 

vector files from the two respective approaches. Only 3.92 

million acres in Utah were jointly classified as pinyonjuniper, pinyon or juniper by the two methods. That means 

each of the methods classified approximately 5.5 million 

acres as pinyon-juniper woodland that the other did not. In 

other words, the USFS-A VHRR and GAP analysis data 

collectively identified a total of more than 15 million acres as 

being dominated by pinyon-juniper, but less than 4 million of 

1992 A VHRR data 

• Pinyon-juniper 

II Coniferous forests 

[] Hardwood forests 

Figure 3-Distribution of pinyon-juniper woodland in Nevada, derived from a USDA Forest 

Service algorithm of AVHRR data (see Powell and others 1994). 

USDA Forest Service Proceedings RMRS-P-9. 1999 149 
150 

I 

r 

• .- :!.r 

.Jtt 

t 

r-

." 

~ .. 

. " 

" .. 

• 

.., 

... 

~:I' 

J 

.J,.II 

~ .#. K t .. II&' 

. . 

.. 

1990 A VHRR data 

Kilometers 

0 10 20 30 40 50 

II Western Woodlands 

(Pinyon-juniper) 

II Western Coniferous 

Forest (Ponderosa pine) 

[J Western Mixed Forest 

(mixed aspen-conifer) 

Nevada 

Figure 4-Distribution of various forest and woodland cover types in eastern Nevada, 

derived from a U.S. Geological Survey algorithm of AVHRR data (see Loveland and 

others 1991). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
.. 

.. . . 

'." :i-. h 

... .. .. 

'-= .-.,.t II- .... .. 

• 

.. 

4 

I .. . .... 

1992 A VHRR data 

Kilometers 

o 10 20 30 40 50 

II Pinyon-juniper 

(I Coniferous forests 

[j] Hardwood forests 

Nevada 

Figure 5-Distribution of various forest and woodland cover types in eastern 

Nevada, derived from a USDA Forest Service algorithm of AVHRR data (see 

Powell and others 1994). 

USDA Forest Service Proceedings RMRS-P-9. 1999 151 
152 

~ . 

\0. .. l.I ..... 

. :.... 

_ ..... . 

. -;: ..... i;l 

.. :{' ~ I 

, 

.~. 

" 

' . .... ,i::. \:. 

J 

.. 

Data Source: 

1992 A VHRR data 

. , . 

. '

Legend 

II Pinyon-Juniper rzl County lines 

Figure 6-Distribution of pinyon-juniper woodland in Utah using AVH RR data with a 1-km2 pixel size 

(see Powell and others 1994). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Data Source: 

USGS BioI. Res. Div. 

II Pinyon 

111 Pinyon 

Legend 

Juniper EJ Juniper 

Ii2I County lines 

Figure 7-Distribution of pinyon-juniper woodland in Utah using GAP data with a 900-m2 pixel size 

(see Edwards and others 1995). 

USDA Forest Service Proceedings RMRS-P-9. 1999 153 
those acres were classified in that category by both methods. 

Based upon the close agreement among FIA, USFS-A VHRR, 

and GAP predictions for the extent of pinyon-juniper 

woodland in Utah, we conclude that the actual coverage is 

about 9.5 million acres. However, its precise spatial distribution remains inconclusive. 

Discussion ---------------------------------- Broad inconsistencies exist between the various sources 

of land-cover data for pinyon-juniper woodlands. In general, the BLM's estimates for their own land exceed that 

provided by remote sensing. The difference in total woodland area on BLM lands, 20.4 million acres versus 14.5 

million acres from the AVHRR estimate, cannot be totally 

accounted for by considering woodJands not containing 

juniper. Moreover, the agreement between the FIA data 

and USFS-AVHRR maps for Utah imply that the BLM 

estimates may be somewhat high. FIA estimates tend to 

track the USFS-AVHRR totals for pinyon-juniper for those 

states where comprehensive plot data are available across 

major landowner categories. 

The relationship between the USFS-A VHRR and Utah 

GAP estimates for pinyon-juniper land cover demonstrate 

the importance of scale (pixel size) and algorithms for defining land cover types when evaluating different protocols. 

Research is obviously needed to develop ways for rectifying 

incompatible attributes of regional and national monitoring 

systems. 

The most efficient monitoring system for making national 

and regional assessments may incorporate both remotelysensed data and data from a systematic structure of ground 

observations. At a minimum, a multi-stage sampling procedure involving plot data could more easily validate cover 

type misclassification of remotely-sensed data. 

Acknowledgments 

We are indebted to Stella Todd and Jock Blackard for 

performing the ARC/INFO analyses. 

154 

References ---------------------------------- Edwards, T.C.,Jr.; Homer, C.G.; Bassett, S.D.; Falconer, A.; Ra msey, 

RD.; Wight, D.W. 1995. Utah GAP Analysis: an environmental 

information system. Technical Report 95-1. Logan, UT: Utah 

State University, Utah Cooperative Fish and Wildlife Research 

Unit. 1189 p. + 2 CD-ROM. 

Joyce, Linda A. 1989. An analysis of the range forage situation in 

the United States. General Technical Report RM-180. Fort 

Collins, CO: U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Forest and Range Experiment Station. 137 p. 

Kiichler, AW. 1964. Potential natural vegetation of the conterminous United States. Special Publication 36. New York, NY: 

American Geographical Society. 116 p. + map. 

Loveland, Thomas R; Merchant, James W.; Ohlen, Donald 0.; 

Brown, Jesslyn F. 1991. Development of a land-cover characteristics database for the conterminous U.S. Photogrammetric Engineering & Remote Sensing. 57:1453-1463. 

O'Brien, Renee. 1999. Comprehensive inventory of Utah's forest 

resources, 1993. RMRS-RB-1. Ogden, UT: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Research Station. 

105 p. 

O'Brien, Renee A.; Woudenberg, Sharon W. 1999. Description of 

pinyon-juniper woodlands in Utah and Nevada from an inventory perspective. In: Monsen, Steven B.; Stevens, Richard; 

Tausch, Robin J.; Miller, Rick. Proceedings: ecology and management of pinyon-juniper communities in the interior West. 

Proc. RMRS-P-OO. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Research Station. 

Powell, Douglas S.; Faulkner, Joanne L.; Darr, David R; Zhu, 

Zhiliang; MacCleery, Douglas W. 1994. Forest resources of the 

United States, 1992. USDA Forest Service General Technical 

Report RM-234 (Revised). Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 132 p. + map. 

Scott,J.M.; Davis, F.; Csuti, B.; Noss, R; Butterfield, B.; Groves, C.; 

Anderson, H.; Caicco, S.; D'erchia, F.; Edwards, T.C.,Jr.; Ulliman, 

J.; Wright, RG. 1993. GAP analysis: a geographic approach to 

protection of biological diversity. Wildlife Monographs. 123.41 p. 

USDA Forest Service. 1989. An analysis of the land base situation 

in the United States: 1989-2040. USDA Forest Service General 

Technical Report FM-181. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 76 p. 

USDI Bureau of Land Management. 1993. Forests: our growing 

legacy. Washington, DC: U.S. Department ofInterior, Bureau of 

Land Management. 19 p. 

West, N.E.; Rea, K.H.; Tausch, RJ. 1975. Basic synecological 

relationships in juniper-pinyon woodlands. In: Gifford, G.F.; 

Busby, F.E. (ed.). The pinyon-juniper ecosystem: a symposium. 

Logan, UT: Utah State University: 41-53. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
155 

Resource 

Values 

Ecology and Management of Pinyon-Juniper 

Communities Within the Interior West: 

Overview of the "Resource Values Session" 

of the Symposium 

James E. Bowns 

Abstract-This paper summarizes 17 excellent, detailed papers 

presented during the section of the symposium on the resource 

values of the pinyon-juniper woodlands. James E. Bowns captures 

the salient points of each paper, a formidable task that required that 

most of the detail be left out. The reader is encouraged to read the 

complete papers for additional details. 

Past, Present, and Potential Uses of 

Pinyon-Juniper 

Pinyon-juniper species are a sizable wood fiber resource 

for products that can be made from smaller, irregular stems 

and those that can capitalize on the unique physical and 

chemical characteristics of these species. 

Firewood obtained from pinyon andjuniper has been used 

longer and more extensively than any other product. This is 

still the main fuel in many rural areas as well as urban use 

in wood burning stoves and fireplaces. These species have 

excellent fuel wood characteristics of heat content, ignition, 

flaming, and fragrance. 

Juniper posts have historically been used because of their 

easy access and natural durability. A good post can last 60 

years, and the diameter ofthe heartwood is the determining 

criterion for durability. Juniper is also used for stub posts in 

power and telephone lines and highway guard rails. Young 

and intermediate aged stands provide the best posts. Pinyon 

is not favored for posts because they are not of suitable form 

or durability. 

Pinyon andjuniper and not widely used for sawn products 

because of the poor growth form and small size. Other 

problems include high wood density and grit in the bark that 

causes excess saw wear and resin build up. 

Railroad ties and mine timbers are some of the usable 

products and are superior to those obtained from local 

softwoods. Furniture and novelty items (book ends, lamp 

bases, clocks, jewelry boxes, and small chests) capitalize on 

the unique fragrance, color, and grain patterns of these 

woods. 

Particle board can be made from both pinyon andjuniper. 

Juniper is somewhat better because of its specific gravity, 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

James E. Bowns is Range Ecologist, Southern Utah University, Cedar 

City, UT 84720. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

texture, color, and fragrance. Markets still need to be developed for these products. 

Cement board can be made with cement, wood fiber, and 

water. It is fire resistant, relatively unaffected by water, and 

can be worked like particle board. 

Charcoal can be made from all species of pinyon and 

juniper; however, more dense woods such as gambel oak are 

superior. Charcoals made from pinyon and juniper were 

used as smelter fuel in early mining operations. 

Although some species of juniper have proven satisfactory 

for pulp, it produces low yields. Other problems are that the 

pulp is too difficult to bleach for white paper, too weak for 

unbleached high-grade bag and wrapping paper, and too 

soft for corrugating board. Economic feasibility for pulping 

pinyon-juniper in the region is questionable. 

Pinyon wood contains large quantities of oleoresin or gum. 

Products obtained from the resin include spirit, linseed oil, 

tung oil varnishes, ester gum, and zinc resinate. The Zuni 

Indians use the resin for an antiseptic, pottery glaze, and for 

burning in religious ceremonies. 

Juniper woods contain large quantities of oily fragrant 

extractives rich in cedrol and associated essential oils. Other 

compounds should include terpene and sesquiterpene. J uniper foliage also contains fragrant oily extractives. 

Other important products include pine nuts and Christmas trees. Nut production is highly variable from area to 

area and year to year, which ca uses problems for nut brokers 

and processors. Pinyon Christmas trees are favored by many 

residents of the Interior West. The single needle pinyon is 

generally favored because it is more symmetrical. 

Role of Pinyon-Juniper Woodlands 

in Aboriginal Societies 

Resources such as food, shelter, tool construction, tinder, 

and preferred settlement locations are available in the 

pinyon-juniper woodlands. These woodlands provided aboriginal peoples some of the most basic raw materials for 

sustaining life. 

Food 

Pine nuts were one ofthe most important foods of the early 

inhabitants ofthe Great Basin and Colorado Plateau. These 

nuts were gathered in large quantities and were considered 

the single most important food species where they occurred. 

The nuts are high in both protein and fats, the proportions 

157 
varying among species. The fat content exceeds that of chocolate and contains all 20 essential amino acids. Nuts provide 

tryptophan, which is deficient in diets of corn farmers. 

Nut production varies from year to year, area to area, and 

age of the tree stand. Pinus monophylla is more productive 

and predictable than P. edulis. A casual relationship has been 

proposed between the unpredictability of pinyon pine nuts 

with the high residential mobility of the Great Basin people. 

Nuts were harvested in the early fall at about the time of 

the first frost and eaten raw or toasted, hulled, winnowed, 

and ground into paste for making a pine nut soup or gruel. 

Soup was sometimes mixed with meat to add flavor and 

Navajos made nut butter, which was spread on corn cakes. 

Nuts were stored in pits or other storage facilities that 

were lined with rocks, grass, or juniper bark and covered 

with bark, branches, dirt, and more rocks. This kind of 

storage ensured that the nuts would tast at least all winter. 

Juniper "berries" were occasionally used for food. Apaches 

ate them fresh or pounded them for bread or juniper tea. 

Utes ate the pulp fresh or dried, or used them as an ingredient in bread or stews. Great Basin people used juniper 

"berries" sparingly, but they were occasionally eaten in the 

fall and winter after they were boiled. 

Medicinal Uses 

The use of pinyon as medicine was limited, but the pitch 

and gum were boiled in water and drunk to purge worms and 

other parasites. Juniper leaves were used in teas for the 

treatment of colds and coughs. 

Construction and Other Uses 

Pinyon and juniper were used for house construction, 

hogans, sweathouses, ramadas, fences, corrals, drying racks, 

and storage facilities. These trees were also used for fire 

material or kindling wood. 

J uni per bark was an integral element in roof construction, 

fiber for mats, diapers, menstrual pads, and cushioning and 

protective lining for storage pits. 

Pitch was used to line basketry water jugs as a sealant, as 

glue for ceramic vessels, and as a mastic for attaching 

projectile points or stone tools. 

Wildlife 

Habitat values ofpinyon-juniper woodlands often receive 

little consideration because they appear so extensive that 

there seems little possibility of exhausting the supply, and 

the aridity and lack of vegetation diversity seems inconsistent with highly productive wildlife habitat. Also, land 

managers may consider mature pinyon-juniper undesirable 

or at least less desirable than earlier seral stages because of 

the lack of understory vegetation. 

Birds 

These woodlands support rich and distinctive bird communities and make substantial contributions to landscapelevel avian diversity. In northeastern Utah pinyon-juniper 

158 

ranked second in percentage of obligate and semiobligate 

species, third in total number of individuals counted, and 

fourth in species richness and diversity. Only riparian areas 

had a higher percentage of obligate or semi obligate species. 

Of seven upland forest habitats studied, pinyon-juniper 

ranked second in total individual birds and third in species 

richness and diversity. In general, the number of species and 

individuals tended to decrease with increasing elevation. 

Consideration of more than simply the number of species 

is important because an area that supports· a few rare 

species can be as important as one that supports many 

common species. 

Studies show that chaining can negatively affect the 

abundance of cavity nesters, timber gleaners, aerial foragers, and species that forage in or next to the foliage. Birds 

that nest or forage on the ground use both treated and 

untreated areas. Woodland treatments are not necessarily 

bad for birds, and creating a mosaic of seral stages provides 

the best balance of habitat features sought by birds. Shrubdependent and edge-associated species benefit from welldesigned treatments. Sites with high edge-to-interior ratios 

should be selected, and more trees should be left standing 

near the edge. This will add structural complexity and thus 

compensate for the loss of overstory. 

Managers should also consider habitat values of mature 

woodlands when meeting watershed and forage production 

objectives. The best option appears to be a landscape designed to include functional patches of all seral stages. 

In another study, 53 bird species, using pinyon-juniper 

woodlands for breeding, were observed on seven pinyonjuniper sites. Only two species, blue-gray gnatcatcher and 

black-throated gray warbler, occurred on all seven sites, and 

77 percent were neotropical migrants. Researchers conclude 

that pinyon-juniper forests are important for the continued 

breeding success ofthese two species and the gray flycatcher. 

Pinyon-juniper forests provide important food, cover, and 

nesting habitat for at least nine neotropical migrants, and 

the pinyon-juniper type supports a greater variety of birds 

than had been anticipated. However, the total number of 

species depending entirely on this type for breeding is low 

compared to other habitat types. 

Sagegrouse depend upon sagebrush steppe throughout 

their distribution. The lack of fine fuels and more mineral 

soil has generally decreased fire frequency, although intensity has increased in some areas. 

Sagegrouse populations have declined in much of their 

former range, and these declines are most notable where 

habitat limitations including loss, fragmentation, and degradation of sagebrush ecosystems have occurred. 

Some sites have been treated with the brush beating of 

short (less than 1 m) pinyon and juniper trees, sagebrush, 

and associated deciduous shrubs. Taller trees were cut with 

chain saws, and some hand cutting removed trees from lek 

sites. 

These treatments doubled sagegrouse populations, and 

the increase was attributed to the decreased mortality of 

males during the breeding season and improved survival of 

both males and females. Prior to the treatments raptors had 

hunted from the trees adjacent to the lek sites, and all 

documented sagegrouse mortality was attributed to predation by raptors. However, the effect of cutting trees was 

confounded because sagebrush beating also occurred at the 

USDA Forest Service Proceedings RMRS-P-9. 1999 
lek sites, which increased the ability of the sage grouse to 

detect predators at greater distances. Pinyon and juniper 

trees were avoided from June through August, at which time 

sagegrouse selected treated areas that had an abundance of 

succulent forbs. 

I t seems remarkable that sagegrouse populations respond 

so quickly to treatments designed to solve an immediate 

local problem. Outside of predation, mortality of this population appeared low and no hunting was allowed. It appears 

that tree removal can increase usable habitat size by at least 

100 percent. 

Mammals 

Small mammals are affected by juniper encroachment, 

conversion, and subsequent impact§) of community structural change. An estimated 341 animal species are found in 

the southeastern Oregon juniper steppe. 

The number of captures is usually higher on cut sites. 

Captures are higher on shrub sites than old-growth woodlands, and the structure provided by robust understory 

vegetation and overhanging juniper skeletons provides superior security and forage in the cut and dropped sites. 

Leaving blocks of unchained vegetation should maintain 

woodland-dependent species while providing increased total numbers of small mammals in treated areas. Total 

captures and number of species are higher in cut sites than 

in uncut sites. This concurs with other studies that show 

that small openings can benefit a variety of wildlife. 

Cut sites have preferred structure, which is provided by 

~ncreased vigor (cover and height) of herbaceous species, 

Increased seed production on cut sites, greater species richness, and juniper slash. Cut sites generally provide increased security and forage for small mammals. 

Opening stands of western juniper and leaving trees or 

thinnings does not substantially affect small mammals. The 

Great Basin pocket mouse appears to be the most sensitive 

species to the loss of shrubs during the latter seral stages. 

Some species such as wood rats are favored by trees. For 

maximum structural diversity shrub steppe communities 

should be managed through early-to-mid-seral woodlands. 

In late and closed woodlands, structural complexity and 

plant diversity results in shifts in small mammal population 

dynamics. 

Fuel wood harvesting results in immediate, drastic, and 

abrupt habitat changes. Small mammals have intricate 

roles in ecosystem function, so they are a key component of 

pinyon-juniper woodlands. 

Slash left on the ground results in an increase of some 

rodent population regardless of overs tory condition. This 

also affects microsite nutrient cycling, understory production, and regeneration of overstory species. 

Overstory removal and slash accumulation seems to have 

more beneficial effects for deer mice specifically and other 

species as well. However, these two effects were detrimental 

to the pinyon mouse. Overstory is important to pinyon mice, 

and burning is of further detriment to this species. 

Burning of slash is considered detrimental and may offset 

the beneficial effects of the slash. Small mammal populations 

are related to overstory adjustments or slash composition. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Mature Utah juniper "berries" are the most commonly 

taken food by gray fox in terms of percent relative frequency 

of occurrence and mean percent of volume in scats. Chemical 

analysis of juniper "berry" hulls indicates that they provide 

the basic supply of nutrients and minerals. Mature juniper 

"berries" are low in moisture, which concentrates more 

energy and nutritional content into the hulls, therefore 

providing more value per unit weight than immature berries 

with high moisture content. The hulls alone provide the 

minimum gross energy needed for gray fox maintenance and 

then some. There may also be some zoopharmacological 

benefits of secondary compounds in purging external parasite loads. 

Mammalian prey, mostly rodents and leporids, represent 

the majority of the diet not consisting of juniper "berries." 

The addition ofthe mammalian prey likely supplements any 

nutritional deficiencies. 

Gray fox contribute to community, structure, dynamics, 

and function of Utah juniper dominated ecosystems. Gray 

fox are efficient foragers that specialize in an interesting mix 

of vegetal and animal matter. The gray fox is the only 

mammal known to forage extensively on the hulls of juniper 

"berries." The hulls comprised a large part of their diets 

during all seasons studied. 

Mature juniper "berries" exist in large quantities and provide a large volume of readily available nutrition throughout the year. "Berries" ripen on the tree and persist for up 

to 2 years. Gray fox are adept at climbing trees and use 

junipers for a food source, resting, and escape cover. 

Juniper seeds pass through the digestive system intact, 

and the metabolic residue in the scat provides the seeds with 

a natural mulch of nitrogen and other minerals. This possibly provides a valuable benefit to juniper community dynamics in the form of seed dispersal. An alternative view 

may be that this seed dispersal is detrimental because it 

increases the spread of juniper that may be interpreted as 

undesirable. 

Apparently gray fox do not actively feed on pinyon pine 

nuts and acorns, which would require the breakdown of the 

shell or husk before they could obtain any nutritional benefit. 

Rocky Mountain Bighorn sheep show a high preference for 

burned areas within pinyon-juniper and ponderosa pine 

communities, especially those burns located within or adjacent to steep, rocky habitat within core use areas. This 

positive response occurs in small or large burns. 

Bighorn sheep generally avoid areas with a high density 

of live or standing dead trees, which reduce visibility to 

intolerable levels. In addition to high visibility, bighorns 

prefer older burns dominated by grass, which constitutes 

79 percent oftheir diet. Early seral stages are more valuable 

to bighorns than tree dominated areas. Therefore, maintenance of bighorn habitat is highly dependent on repeated 

burning or bighorn densities will be low. 

Amphibians and Reptiles 

The distribution, abundance, and habitat affinities of amphibians and reptiles have been documented in pinyonjuniper woodlands. Four species of amphibians and 26 species of reptiles were found. Of the reptiles, 50 percent were 

snakes. The speckled rattlesnake and striped whipsnake 

159 
were the only snakes common throughout the zone, but the 

distribution of most snakes is still poorly understood. Seven 

species of reptiles extended into the bristlecone-limber pine 

zone. 

Toads, frogs, skinks, and salamanders are found near 

springs, ponds, and seeps. This emphasizes the importance 

of wet areas for these species. The generally unrecognized 

diversity of herptofauna in these woodlands, along with 

specific research and management needs, have been 

documented. 

Endemic and Endangered 

Plants 

Nearly all plants of Utah and other Western States that 

are listed as threatened, endangered, or sensitive are narrow endemics, which are defined as plants restricted to one 

or a few counties in one or perhaps two States. 

Within the pinyon-juniper thermal belt plant generalists 

are found on nearly all geologic strata and soil types, but 

pinyon-juniper and desert shrub communities also support 

most of the narrow endemics in Utah. 

Edaphic control of vegetation by geologic formations is 

greatest where geologic strata are exposed, and the area 

must be xeric in order for the substates to be controlling. 

Dessication is apparently necessary for the ultimate expression of edaphic control, and this is not as common at higher 

precipitations. Water tends to override the influence of 

geology. Xeric conditions are also associated with steep 

slopes, clifffaces, and wind swept slopes where plant specialists are protected from the competition of generalists. Relatively few narrow endemics are found where the area is well 

mantled with vegetation. Therefore, Utah, with much exposed geology and xeric conditions, supports numerous, 

relatively narrow endemic plants. 

Specific taxa have been arranged into three categories of 

apparent relationships to pinyon-juniper. Each taxon is 

named, the geology and soils !1re discussed, and notes are 

made on each species. These categories are (1) obligatory or 

semiobligatory to pinyon-juniper, (2) apparent associates 

mostly in the interspaces of trees and exposed geologic 

substrates, and (3) incidentals, which are found within the 

pinyon -j uni per but extend below into the sal t desert shrub or 

above the pinyon-juniper on wind swept slopes and ridges. 

Apparently, narrow Utah endemics have evolved where 

geology and erosion are the primary drivers of plant community composition or dynamics, and these plants are unable to 

compete with generalists on well-developed soils. Narrow 

endemic plant population densities are often low, and survival is more a function of adaptation to harsh substrates 

and dry conditions than their ability to compete. 

Semibarren habitats, which have low potential for vegetation manipulation, are occupied by these narrow endemics, 

and these species can be used as indicators of these low 

potential sites. Sites better suited for the high production of 

shrubs and herbaceous species are unsuitable for narrow 

endemics. 

The strong relationship between highly erosive, geologic 

strata, and narrow endemics indicates an evolutionary situation dependent on harsh conditions and high rates of 

160 

erosion. This condition predates the advent of Europeans 

and their livestock by thousands of years. 

Most potential conflicts can be resolved where there are 

well-documented inventories and an understanding of the 

habitat requirements and biology of narrow endemics. 

Old-Growth Pinyon and Juniper 

Woodlands _________ _ 

Old-growth pinyon-juniper woodlands do not fit the typical image of old-growth coniferous forests. However, some of 

the oldest stands throughout the Intermountain West are 

low statured, open, semiarid woodlands. 

Old woodlands usually differ in structure and function 

from postsettlement woodlands, thus adding diversity at the 

community and landscape levels. Concern over the rapid 

expansion of these woodlands during the 20th century has 

overshadowed the presence and values of presettlement 

woodlands. In addition, wildlife studies have generally not 

separated postsettlement from pre settlement stands. 

Pinyon-juniper woodlands should be defined on the basis 

of tree age and stand structure and function. One age 

separation may be on the basis oftree establishment prior to 

European settlement. In the Great Basin rapid expansion of 

these woodlands coincided with settlement in the late 1860's 

and 1870's. Old growth can also be based on the structural 

characteristics of the trees. With age, canopy morphology 

shifts from a cone shaped to a rounded top. As trees age they 

may exhibit broad asymmetrical tops, deeply furrowed bark, 

twisted trunks or branches, dead branches and spiked tops, 

large lower limbs, narrow strips of bark, hollow trunks, large 

diameter to height ratios, and bright yellow lichens on the 

branches. Western and Utah juniper ages can exceed 1,000 

years and pinyon 600 years. 

At the community level, old-growth woodlands should be 

described on the basis of the presence of old trees and 

structural characteristics such as standing and down dead, 

decadent living trees, cavities,and lichen-covered branches. 

The pinyon-juniper type has been described as climax with 

woodlands shifting to grasslands or shrub steppe only following a disturbance such as fire. In the absence of a 

disturbance, these communities will eventually return to 

woodland. Old-growth woodlands occur over a wide range of 

parent materials, soils, aspect, slope, elevation, climate, and 

disturbance regimes. 

Ecological provinces may provide a first separation in the 

classification of old-growth woodlands. A current system 

considers: (1) community type based on ecological province, 

land form, dominant shrubs and grasses, soils, and topography; (2) tree age composition and structure; and (3) understory composition. Age classes are subdivided under 

presettlement and postsettlement categories. 

Researchers have described 13 old-growth woodland types 

of prehistoric and presettlement distribution and changes, 

extent and proportion of old growth, soils, species composition, wildlife values, and other attributes. 

What should old-growth stands be managed for? These 

old-growth woodlands make up only a small percentage of 

pinyon-juniper woodlands, and they are structurally and topographically more complex than the younger, more abundant 

USDA Forest Service Proceedings RMRS-P-9. 1999 
woodlands. Old-growth is esthetically pleasing and provides 

recreational, cultural, and spiritual opportunities. 

Fire policies influencing these old stands should be evaluated for both suppression and let burn. Fuelwood cutting has 

been considered wasteful unless cutting is designed to remove postsettlement trees and restore presettlement stand 

structure. 

Studies are needed to determine and describe the range of 

old-growth woodlands. It is also important to evaluate 

presettlement and postsettlement changes in community 

structure and composition, define desired future conditions, 

and develop management plans for restoring or maintaining 

old-growth woodlands. These old stands are an important 

landscape component that support many plant and animal 

species, and interact with adjacent community types. 

Pinyon and Juniper 

Watersheds 

Erosion and Deposition 

When juniper canopies begin to mature and close, 

microtopographic elements become more pronounced. Coppice dunes or mounds beneath the trees are evident. These 

dunes are higher under the trees than in the interspaces. 

Within the interspaces, the soil surface can be as much as 

1 m lower than at the trunk and are usually covered with 

gravel. Under the trees the soils are relatively fine-textured 

and incorporated with leaf litter. The dunes or coppices 

absorb the energy of flowing water and restrict the sediment 

delivery downslope. 

One question is ifsites dominated by maturejuniper trees 

represent degraded or degrading systems. One postulation 

that juniper successional trajectories are currently in place 

and are likely to continue for centuries due to the longevity 

of these trees, resulting in a self-destructing system. Therefore, it is necessary to identify sediment source and sink 

relationships, which will help identify the need for custodial 

or active management. 

Soil under the trees has an organic horizon that is absent 

in the interspaces. A petrocalcic horizon appears to restrict 

the downward growth of roots and impede water percolation 

and vertical nutrient flux. This horizon is deeper under the 

coppice dune and nearer the surface in the sparsely vegetatedinterspace. The sagebrush fluve has a weakpetrocalcic 

layer. 

Preliminary findings suggest that horizonation is different between coppice dunes, interspaces, and sagebrush 

fluves, which might influence the distribution of vegetation. 

Further studies of this problem are ongoing. 

Hydrology and Spring Occurrence 

Removal of junipers has altered the hydrologic regime of 

several small watersheds, resulting in large increases in 

springs and water yields. A Coordinated Resource Management Plan was developed for the purpose of increasing and 

maintaining the availability and duration of surface flows, 

enhance ground water recharge, increase and maintain 

USDA Forest Service Proceedings RMRS-P-9. 1999 

plant diversity, and structure and provide quality habitat 

for wildlife and livestock. 

Chaining and seeding, wildfires, and prescribed burning 

have resulted in numerous seeps, wet meadows, and perennial springs emerging. Previously dry stream channels are 

developing into riparian areas. However, some negative 

effects are slope instability and seepage erosion. 

The hypothesis proposed for this phenomenon is that most 

springs occur at points of subsurface flow concentration 

where a shallow soils mantle exists over low permeability 

bedrock such as shale or where water may flow through a 

confined aquifer of fractured bedrock or bedrock containing 

solution cavities. Flow might also be controlled by structural 

features such as faults. 

Preliminary results suggest that most subsurface flow is 

through fractured bedrock that might create discrete packets of infiltration, transfer, and discharge. Unique geology of 

a site may force ground water to the surface, allowing 

increases in water yield to be readily exploitable. 

Watershed Scale Research 

New research is being developed to address the problems 

encountered when dealing with extremely variable site 

conditions and protracted time scales. 

The specific objectives are to (1) establish a long-term 

watershed-scale research site on semi-desert and upland 

climate zones and (2) perform mechanistic research in pinyon-juniper woodlands that will study ecosystem dynamics 

such as energy flow, water and nutrient cycling, organismal 

structure and function, and sediment source/sink relationships. At the same time, the project will address the more 

pragmatic concerns associated with management objectives, the effects of drastic disturbances and the results of 

custodial management. 

The design utilizes small watersheds and spatial nesting 

of tributary basins and provides integration of spatial and 

temporal variability on a realistic scale. Potential treatments will include (1) mosaic thinning, (2) simulated wildfire, (3) mechanical manipulation (chaining), and (4) an 

untreated control for evaluating carbon sequestration, 

seed dispersal and population dynamics, and social 

considerations. 

Watershed Values and Conditions 

Pinyon-juniper woodlands are of significant economic 

value for spring-fall livestock grazing and big game winter 

range. This has led to vegetation manipulations to improve 

these values. Fire is a natural disturbance, and its frequency 

and timing are major factors in vegetation dynamics. Precipitation is often inadequate for high plant cover, but is 

often of sufficient intensity to produce localized runoff and 

erosion. Plant composition and structure is extremely important for preserving soil resources because of its basis for 

all other values. 

The hydrology ofthese watersheds is a function ofprecipitation amount, intensity and seasonality, the geology as it 

relates to topography, subsurface porosity, and surface soils 

and understory-overstory vegetation dynamics. When trees 

161 
are dominant, there is a high transpiration component and 

high exposure of surface soils between trees that are major 

sources of runoff and erosion. Geologic parent materials are 

mainly sedimentary rocks such as limestones, dolomites, 

shales and sandstones, and igneous rocks. These woodlands 

are found on mesas, foothills, breaks, mesa edges, escarpments, and depositional areas. Soil surveys indicate that 

pinyon and juniper occur on almost all textural groups, and 

these woodlands are not necessarily limited by texture, 

stoniness, or depth. 

It is difficult to characterize pinyon and juniper sites 

hydrologically because of the great variability in soils, geological substrate, slopes, and precipitation patterns. Studies 

have shown that evapotranspiration is the major process of 

water loss, and runoff is less than 10 percent of the water 

budget. This usually results in little water yield in the form 

of runoff or ground water recharge. -There are still many 

cases oflocalized runoff, erosion, down stream flooding, and 

deposition from pinyon-juniper dominated drainages. The 

combination of s ufficien t preci pitation (usually over 450 mm 

per year) and an impermeable layer can create a zone of 

saturation, and the resulting interflow may be sufficient to 

feed springs and streams. 

Fire occurs in pinyon-juniper when there is sufficient 

understory to carry it from tree to tree, or when tree canopies 

"close up" enough for fire to spread from crown to crown. 

Evergreen pinyon and juniper trees have the ability to 

accumulate carbon slowly and efficiently by more active 

year-round photosynthesis than associated herbs and shrubs. 

This, coupled with their tree growth form, allows the trees to 

build large above and below ground structures for capturing 

resources. Under these semiarid conditions, much of the 

limited precipitation is taken up by the tree's extensive root 

systems and transpired through their canopies. Tree-root 

exploitation of water and nutrients from the interspaces 

often results in the eventual purging of the understory 

plants in the absence of fire or other tree-killing disturbances. 

Prior to European settlement, pinyon-juniper woodlands 

were open, sparse savannahs or were confined to rock, 

ridges, and shallow soils where fine fuels were too low to 

carry fires. The highest period of tree establishment beginning in the mid-1800's was downward in elevation and 

resulted in reduced understory fuels necessary to carry 

fires. The change in fire frequency came about initially with 

heavy understory grazing and removal of fine fuels in the 

late 1800's to early 1900's, and later with fire suppression 

following World War II. 

Geologic substrate, soil, and climate interact to affect 

hydrologic responses and interactions. Parent materials 

produce soils with different infiltration, water-holding capacity, and fertility. Volcanic soils, with high fertility, support the most rapid invasion ofpinyon-juniper in the absence 

of fire. Interspace erosion associated with the loss of nutrients, mycorrhizal fungi, cryptogams, and water-holding 

capacity can result in permanent loss of understory potential. Such sites may remain as degraded woodlands with 

little diversity and high runoff potential. This erosion may 

also result in the loss of archeological values. 

Pinyon and juniper woodlands have been subjected to a 

range of environmental and human-induced disturbances 

over the years. During the precontact period there were 

162 

natural and Native American-induced fires and climatic 

fluctuations. After the mid-1800's came grazing, logging, 

and fire control. The loss of herbaceous forage and increases 

in woody vegetation led to the development of brush control 

and revegetation technologies applied to pinyon-juniper, 

sagebrush, and other rangelands. It is important to remember the site and situation-specific nature of responses to 

vegetation manipulations. Resource management is both a 

science and an art and requires experience and familiarity 

with specific conditions and responses to specific management. 

Tree control projects are usually conducted to increase 

forage yield, to improve watershed conditions, to increase 

water yield, and to improve wildlife habitat. The most 

critical is to improve watershed conditions. Most control 

projects were conducted from the 1940's through the 1960's 

but dropped off in the 1970's. 

The traditional view is that pinyon and juniper communities, especially on invasion sites, will degrade hydrologically 

and ecologically unless periodic fire or other tree reductions 

and associated natural revegetation or seeding allow for 

increased herbaceous and shrub cover. Proponents of this 

view are concerned that continuing fire control and lack of 

other tree control measures are threatening the soils and 

associated resources. The counter position is that maturing 

woodlands are not eroding and degrading, and land managers may be using unfounded hydrologic or other benefits to 

increase forage for livestock. Others may be using similar 

selective interpretations and self-serving speculations to 

prevent tree control practices. Proponents of both views 

seem to agree that grazing and site-specific conditions have 

affected hydrologic responses and that tree dominance can 

deplete understory vegetation and seed banks. 

There are enough pinyon-juniper woodlands (about 30 

million ha or 74 million acres) that we can be selective in 

vegetation management to improve wildlife habitat, increase forage for livestock, and benefit hydrologic processes. 

Multiple Use Management Based on 

Diversity and Capabilities 

The determination of which uses to provide and where to 

provide them must be based on the land's capabilities and 

human and wildlife preferences. 

The capacity ofpinyon-juniper to dominate plant communities has been termed "super dominance" in reference to 

their ability to greatly oppress understory species and outlive the seed banks of these species. Successional stages of 

pinyon-juniper woodlands are not necessarily discreet, isolated stages but merely points along a continuum. The use 

ofthe term "stages" is used to facilitate communication. The 

following are stages often used to describe successional 

processes. 

• Fire and Skeleton Woodland-In the first stage, live 

crown cover is reduced to or near zero, and the community looks totally devastated. If burning occurs before 

the closure of pinyon-juniper has purged the understory, the black surface persists only until sprouting 

species appear or seeds germinate from seed banks. If 

the understory has been purged and the site not seeded, 

the invasive species such as cheatgrass occupy the site. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
• Annual Stage-This stage may be skipped if the burn 

occurred before the understory had been purged. Rapid 

crown cover of annuals is greatly facilitated by cheatgrass. This annual stage can be perpetuated by frequent 

fires that are fueled by cheatgrass. This stage can 

persist for 20 years and on southerly exposures up to 80 

years. 

• Perennial GrassIForb-This community can follow 

directly after fire if the perennial understory had not 

been purged by pinyon-juniper closure. Seeding has 

been successful in establishing good ground cover within 

5 years postfire where understory has been purged. 

Without seeding, cheatgrass can delay dominance of 

this community for 20 or more years. 

• Shrub/Grass-This community can also follow immediately after a burn where sprouting shrubs and herbaceous species had not been purged. Where pinyonjuniper crown cover has been as high as 60 percent prior 

to burning, the shrub cover is often less that 2 percent 

10 years postfire. In the absence of sprouting shrubs, 

crown cover may reach 20 percent or more in about 30 

years postfire. This stage persists for about 50 years. 

• Shrub/Open Tree-In this stage, crown cover of pinyon-juniper increases to about 20 percent. There is often 

a linear decrease in understory cover at about 5 to 20 

percent pinyon-juniper crown cover. A prominent feature of this stage is the dense tree limbs extending to the 

ground level. Trees of various ages contribute to structural diversity, and this stage appears to be the most 

complex or diverse structural canopy in the sere. Ground 

cover is high for soil and watershed protection, and this 

stage is common for about 60 to 100 years postfire. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

• Tree/Shrub Stage-This stage is sometimes not distinguished from the previous stages. Tree cover increases from 20 to 40 percent with a pronounced decrease in shrubs and herbaceous species. Understory 

species of previous stages begin to be purged. This stage 

is common for 100 to 200 years postfire. 

• Mature Pinyon-Juniper-At this stage, tree crown 

cover is typically greater than 40 percent. The crowns 

are larger and more open than in previous stages, and 

lower branches are pruned off over time. Shrub and 

herbaceous layers are complete1Y purged by this time. 

Cheatgrass remains at low levels, and its nearly ubiquitous distribution indicates that it will dominate the 

future early seres. Bare inters paces develop and persist 

in which rills and sheet erosion reach the highest levels 

except for the skeleton stage. This stage persists for 

about 200 years or until the next disturbance. 

Capabilities and Values 

Capabilities are a function of climate, geology, soils, gradient, aspect, plant taxa, variability of sera I and plant communi ties, and other ecological features specific to the site. Values 

are a function of animal reaction to these features and the 

human perception and preference for points of a sere. Each 

seral stage is capable of supporting a different set of needs and 

desires. Each plant community has intrinsic value, and the 

value of each stage can vary widely within a diverse public. 

Therefore, a mix of successional stages facilitates multiple 

use and a diversity of values. Higher resource values can be 

expected where the mix is taylored to the capabilities and 

values of specific ecological units within the landscape. 

163 
Multiple Use Management Based on 

Diversity of Capabilities and Values Within 

Pinyon-Juniper Woodlands 

Sherel Goodrich 

Abstract-Different wildlife species respond differently to different seral stages of pinyon-juniper ecosystems. People also have 

widely different preferences and uses associated with different 

stages of succession. Bighorn sheep prefer early seral communities, 

while forage values for elk and mule deer are much higher in early 

to mid seral stages, and mature stands provide hiding and thermal 

cover. Trees used as Christmas trees are more common from young, 

open stands. Some birds require older stands for seed. Pinyon seed 

crops are important commercially and for personal use. Some 

wildlife species are cavity nesters and require large trees in mature 

stands. Firewood and cedar posts come from mature stands. Watershed values can also vary with seral stage. Visual and intrinsic 

preferences vary greatly among individuals. To integrate such 

diverse values into management for multiple uses, managers use 

tools that include an inventory of ecological units, and studies and 

recorded observations for each ecological unit, to understand capabilities and values of separate units within landscapes. Application 

of such an inventory to multiple use management is explored. 

Under the Multiple use Sustained Yield Act of 1960 and 

the Environmental Policy Act of 1970, management for a 

diversity of values is appropriate for National Forest lands. 

Legal, Congressional, or administrative mandates aside, 

providing a diversity of uses on public land seems appropriate. Determination of which uses to provide and where to 

provide them must be based on the land's capabilities and 

human and wildlife preferences for various landscape features. Within pinyon-juniper ecosystems, the sum ofsuccessional stages or the sere is a major component of capability. 

Capabilities of a sere vary with ecological units. 

Pinyon and juniper trees themselves are obvious and 

meaningful indicators of values related to different seral 

stages. However, mature stands of these trees can obscure 

variability in capabilities related to other successional stages. 

The capacity of pinyon-juniper to dominate plant communities is so complete that West and Van Pelt (1984) used the 

term "super dominance" in reference to their ability to 

greatly oppress understory species and outlive the seed 

banks of these species. Thus, describing potential uses of 

pinyon-juniper ecosystems in terms of climax vegetation 

(pinyon-juniper overstory with depleted understory) is 

In: Monsen, Stephen B.; Stevens, Richard, camps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Sherel Goodrich is Forest Ecologist, Ashley National Forest, Vernal, UT 

84078. 

164 

unsatisfactory because it gives little indication of what other 

vegetative mixes can occur in the sere (Hironaka 1987), and 

therefore what other values could be provided. Use of geology, geomorphology, gradient, aspect, vegetation, soils and 

other features as descriptors of ecological units provides a 

broad base for classification and inventory (Wertz and Arnold 

1972) that is not dependent on climax vegetation. Such an 

approach to classification and inventory has been used in the 

Green River corridor of Daggett County, Utah, which is the 

focus of this paper. 

Pinyon-Juniper Successional 

Stages of the Green River 

Corridor 

To facilitate a discussion of capabilities and values, I 

present some features of different successional stages. The 

successional sequence is patterned after Erdman (1970), 

Everett (1987), and Barney and Frischknecht (1974). This 

sequence appears to be highly applicable to pinyon-juniper 

woodlands of the Green River corridor. Successional patterns explained by Everett (1987)-including depletion of 

the understory with increase in pinyon-juniper cover and 

eventual purging of the understory when mature pinyonjuniper reach potential crown closure-are highly applicable in the Green River corridor (Huber and others, these 

proceedings). West and VanPelt (1987) noted that successional stages are not isolated stages but points along a 

continuum. However, the concept of stages can facilitate 

communication. Features given are those observed and 

measured in the Green River corridor and are not necessarily those given in the above cited works. 

Fire and Skeleton Woodland 

Crown cover-Live crown cover is reduced to zero or 

nearly so. 

Structure-Pinyon -j uni per are red uced to skeletons wi th 

fines less than 1 or 2 cm in diameter mostly removed. Pinyon 

begin to fall within the first 10 years after fire, while many 

juniper skeletons remain standing for three or more decades. Herbaceous species and many shrubs are consumed 

to near ground level or nearly so. 

Plant composition-The community looks totally devastated without apparent composition. 

Years-If burned before closure of mature pinyonjuniper has purged the understory, the blacked surface of 

USDA Forest Service Proceedings RMRS-P-9. 1999 
the skeleton woodland persists only until precipitation and 

warm temperatures activate sprouting species and the seeds 

of seed banks. Where closure of pinyon-juniper has purged 

the understory and where the site is not seeded, the black 

and desolate appearance might persist for 1 to 2 years while 

invasive species, including cheatgrass (Bromus tectorum), 

respond to the open site. 

Annual 

This stage is essentially skipped over where stands are 

burned before the understory has been greatly reduced by 

pinyon-juniper closure. 

Crown cover-Crown cover of exponentially increasing 

annuals including cheatgrass increases rapidly. Long-lived 

seed banks such as those of a few mustards (Brassicaceae) 

and annual chenopods (Chenopodiaceae) add to crown cover 

in some stands. Crown closure of 60 to 80 percent can be 

achieved in 5 to 10 years. This rapid crown closure of ann uals 

is greatly facilitated by cheatgrass. 

Structure-Structure is limited to the skeletons of the 

trees and the annual herbaceous layer. 

Plant composition-Annuals dominate the community. 

These incl ude cheatgrass, Japanese chess (Bromusjaponicus 

Thunb.), tansy mustard (Descurainia pinnata [Walt.] Britt.), 

false flax (Camelina microcarpa Andrz. in DC.), Jim Hill 

mustard (Sisimbrium altissimum L), prairie pepperweed 

(Lepidium densifolium Schrad.), narrow leaf goosefoot (Chenopodium leptophyllum (Moq.) Wats.), wild tobacco (Nicotiana attenuata Torr. ex Wats.), knotweed (Polygonum 

douglassii Greene), floccose gilia (Gilia inconspicua [Smith] 

Sweet), Russian thistle (Salsola spp.), annual cryptanths 

(Cryptantha spp.), blue-eyed Mary (Collensia parviflora 

Lind!.), and western stick seed (Lappula occidentalis [Wats.] 

Greene). Biennials and short-lived perennials such as hoary 

aster (Machaerathera canescens [Pursh] Gray) are sometimes also a part of this early successional stage. 

Of the seed bank species: wild tobacco is particularly 

noteworthy. Where it has not been seen prior to burning, it 

has expressed itself in abundance the year after fire. Within 

3 years of abundant expression after fire, this plant is 

commonly not seen again. This indicates the production of a 

seed bank that is activated only by fire or perhaps other 

disturbance. Life ofthe seed bank for this species is indicated 

to be at least several decades and possible up to 200 years. 

Also, invasive species with highly mobile seeds are able to 

colonize these communities. Mobile seeds and aggressive 

colonization are features of prickly lettuce (Lactuca serriola 

L.), and introduced thistles including Canada thistle (Cirsium 

arvense [L.] Scop.) and musk thistle (Carduus nutans 1.) 

which are classed as noxious weeds in several Western 

States. 

Ground cover-Ground cover is reduced to near zero 

percent with fire. Were high percent crown closure of pinyonjuniper was associated with a purged understory, ground 

cover is comparatively slow to develop and is much a function cheatgrass and other annuals and the litter they produce. Cheatgrass can be quite effective in producing ground 

cover, but the quality of this cover for watershed protection 

is of somewhat lower value than that of perennial species. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Years-With highly competitive species such as 

cheatgrass, this stage can persist for 20 years and much 

longer where the perennial understory had been purged by 

closure of mature pinyon-juniper stands. On southerly exposures of the Green River corridor, cheatgrass has been found 

as the dominant 80 years postfire (Goodrich and Gale, these 

proceedings) where it appears it can persist as the dominant 

until pinyon and juniper return as dominants. This annual 

stage can also be perpetuated by frequent fires that are 

fueled by an abundance of cheatgrass. 

Perennial Grass/Forb 

This community can follow directly after fire where closure of mature pinyon-juniper has not purged perennial, 

understory plants. 

Crown cover-This remains a function of herbaceous 

species. 

Structure-Structure is limited to the skeletons of the 

trees and the herbaceous layer. 

Plant composition-Bluebunch wheatgrass (Elymus 

spicatus [Pursh] Gould) with as many as 40 other herbaceous species form communities on northerly (cool) exposures. Communities with fewer species form on warm (southerly exposures). These include: Indian ricegrass (Stipa 

hymenoides R. & S.), bluebunch wheatgrass, Ross sedge 

(Carex rossii Boott), needle-and-thread grass (Stipa comata 

Trin. & Rupr.), Sandberg bluegrass (Poa secunda Pres!.), 

and hairy golden aster (Heterotheca villosa [Pursh] Shinn.). 

Ground cover-Quality and quantity (including dispersion) of ground cover rapidly improves to provide adequate 

soil and watershed protection where closure of preburn 

pinyon-juniper communities had not greatly impaired the 

understory. Seeding has been highly successful in establishing high percent ground cover within 5 years postfire where 

the understory had been purged. Quality and quantity of 

ground cover is a function of numerous fine-stemmed, closely 

spaced perennial plants and the litter they produce. 

Years-Rapidity of development of perennial grass/forb 

communities highly depends upon closure ofpinyon-juniper 

prior to burning and the dynamics of cheatgrass and other 

invasive species after burning. Heavy infestations of 

cheatgrass especially on warm exposures can delay the 

dominance of these communities for 20 or more years and 

much longer where they are not seeded. Many of the other 

annuals decrease rapidly with the development of perennial 

communities. Without seeding and with little or no cheatgrass 

competition, this community is usually well developed within 

3 years postfire. With seeding this communities can be well 

developed within 2 years postfire even with strong presence 

of cheatgrass. 

Shrub/Grass 

Shrub/grass communities can develop immediately after 

fire where closure of mature pinyon-juniper have not purged 

the understory of sprouting shrubs and herbaceous species. 

Crown cover-Crown cover rapidly increases where 

sprouting shrubs and herbaceous species were not purged by 

165 
closure of mature pinyon-juniper stands prior to fire. Crown 

cover of sprouting shrubs can be near preburn levels within 

seven growing seasons after fire where combined crown 

cover of pinyon and juniper was only about 10 to 15 percent 

prior to fire (Huber and others, these proceedings). Where 

combined cover of pinyon-juniper was as high as 60 percent 

prior to fire, shrub crown cover is often less than 2 percent 

10 years postfire. In the absence of sprouting shrubs, shrub 

recovery is slower with crown cover sometimes reaching 20 

percent or more in about 30 years postfire. 

Structure-Tree skeletons and especially those ofjuniper provide some structure. Shrub layers become more 

complex with taller shrubs such as alder-leaf mountain 

mahogany (Cercocarpus montanus Raf.) and serviceberry 

(Amelanchier alnifolia Nutt.) overtopping big sagebrush 

(Artemisia tridentata Nutt.), snowberry (Symphoricarpos 

oreophilus Gray), yellowbrush (Chrysothamnus viscidiflorus 

[Hook.] N utt.), and other lower shrubs with an understory of 

herbaceous species. Bitterbrush (Purshia tridentata [Pursh] 

DC.) increases in some places usually after big sagebrush. 

Plant composition-Herbaceous species are the same 

as for the perennial grass/forb stage with shrubs including 

those listed above becoming more dominant. 

Ground cover-Ground cover has generally reached 

potential prior to this stage, and it remains at or near 

potential through out this stage. With numerous finestemmed perennial plants closely spaced, quality and quantity of ground cover are of high value for soil and watershed 

protection. 

Years-This stage persists for up to 50 or more years 

postfire with some minor return of trees where crown cover 

of these trees remains less than 3 percent. 

Shrub/OpenTree 

Crown cover-In this stage crown cover of pinyonjuniper increases to about 20 percent. Everett (1985) found 

a linear decrease in cover of understory species from about 

5 to 20 percent crown cover of pinyon-juniper. However, 

visual appearance of crown cover of shrubs and herbaceous 

species remains about the same as for the shrub/grass stage 

until pinyon-juniper crown cover reaches about 10 percent. 

Structure-Structure of the shrub and herbaceous layers remains diverse. A prominent feature of this stage is 

trees with dense limbs that extend to ground level. These 

young trees add another tall layer, and they contribute to the 

diversity of lower layers of structure. Return of trees is 

typically uneven aged, and thus trees of various ages contribute to structural diversity. This appears to be the most 

complex or diverse structural canopy stage in the sere. 

However, it does not provide large boles and soft wood of 

decay needed by cavity users to excavate cavities. Also, this 

stage does not provide tall trees with large limbs preferred 

by some birds including raptors. 

Plant composition-Other than the addition of pinyonjuniper, composition remains similar to the previolls stage. 

Although some understory species decrease, few are forced 

out of the community. 

166 

Ground cover-Ground cover remains at high value for 

soil and watershed protection. 

Years-This stage is common from 60 to 100 years postfire. 

Tree/Shrub Stage 

This stage is not separated from the previous stage by 

Erdman (1970) or by Barney and Frischknecp.t (1974). It is 

separated in this paper for management implications. Fire 

or other treatment applied to the previous stage will maintain a more resilient understory than if applied to this stage. 

Crown cover-Combined crown cover of pinyon and 

juniper increases from about 20 to 40 percent with a pronounced decrease in crown cover of shrubs and herbaceous 

species. Sagebrush often becomes decadent while bitterbrush, alder-leaf mahogany, serviceberry, and snowberry 

persist longer with greater apparent vigor, but they also 

show reduced numbers, crown size, and vigor. 

Structure-Tree structure incl udes dense limbs to near 

ground level with larger bole and limbs than in the previous 

stage, but still hardly of size and sufficient decay to be 

selected by cavity nesting species and larger birds for nest 

sites. However, due to the uneven age oftrees, some begin to 

provide this larger structure. During the latter part of this 

stage, pruning of lower limbs of juniper and especially 

pinyon is generally initiated, and some trees begin to appear 

mature. Structure of the shrub and herbaceous layers declines. Return of trees is typically uneven aged, and thus 

trees of various ages contribute to structural diversity. 

Skeletons of trees continue to provide some structure, but 

they become less conspicuous as they fall and as live trees 

increase. 

Plant composition-Understory species present in previous stages begin to be purged from the community. Purging continues throughout this stage during which sagebrush 

and other species can be eliminated or nearly so. 

Ground cover-As the understory is purged, quality and 

quantity of ground cover is decreased partly as a function of 

lower dispersion of ground cover. As trees mature, they draw 

more resources of the site into the area of their crowns. 

Plants in interspaces begin to thin and bare soil is exposed. 

Litter is increasingly confined to directly beneath the trees. 

Years-This stage is common from about 100 to 200 years 

postfire. 

Mature Pinyon-Juniper 

Crown cover-Combined crown cover of pinyon-juniper 

is typically greater than 40 percent and can be as high as 60 

percent or more. 

Structure-Structure is largely a function of trees with 

large boles, large limbs, and more open and larger crowns 

than in previous stages. Also, decay within large boles 

increases with age, which is important to cavity using 

wildlife species. Some younger or smaller trees persist. 

However, large and small trees are usually pruned oflower 

branches over time. Purging of shrub and herbaceo us layers 

USDA Forest Service Proceedings RMRS-P-9. 1999 
is completed in this stage with sagebrush generally going 

first and bitterbrush and mountain brush species persisting 

longer. 

Plant composition-Purging of the understory is carried to a high degree with relatively few individuals of 

comparatively few species remaining. Shrubs are often totally purged. Remaining herbaceous species include Sandberg 

bluegrass, Ross sedge, rock goldenrod (Petradoria pumila 

[Nutt.] Greene), and pussy toes (Antennaria microphylla 

Rydb). Cheatgrass remains in the community at low levels. 

The nearly ubiquitous distribution of this species indicates 

it will dominate the early part offuture seres throughout the 

pinyon-juniper belt of the Green River corridor. 

Ground cover-Interspaces become nearly void of plant 

and litter cover especially on southerly aspects. Where sites 

are productive enough to support -dense trees with the 

crowns essentially continuous, a nearly continuous duff 

layer can develop. However, more commonly large, bare 

interspaces develop and persist in this stage in which rills 

and sheet wash reach the highest levels in the sere except for 

the fire and skeleton stage. 

Years-This stage persists from about 200 years postfire 

and until the next disturbance. 

Capabilities and Values 

Capabilities are a function of climate, geology, soils, gradient, aspect, plant taxa, variability of seral and mature 

plant communities, and other ecological features particular 

to a specific site. Values are a function of animal reaction to 

these features and human perception and preference for 

points of a sere. 

The sere is a major expression of capabilities. Each stage 

of succession is capable of supporting a different set of needs 

for wildlife and other values. Wildlife might also be used to 

define capabilities. However, composition and percent crown 

cover and structure of vegetation and forage provided by 

vegetation function well to define wildlife capabilities, for 

these are features to which wildlife species respond. Some 

species also respond to geologic structure such as rock 

outcrops. Visual values are also a function of geologic features as well as vegetation, and they should be included in 

an evaluation ofland capabilities. With a broad spectrum of 

geological substrates, soils, aspects, and seral communities, 

pinyon-juniper woodlands present a wide array of capabilities and values. 

Breeding bird surveys from the Green River corridor show 

a relatively high value of mature pinyon-juniper woodlands 

for high diversity of species, total number of birds, and for 

obligate and semiobligate species (Paulin and others, these 

proceedings). Other workers have also found similar pinyonjuniper obligates and semiobligates (Cherry 1982; Balda 

and Masters 1980; Fitton 1989). These include bark-gleaning, cavity-nesting insectivores such as chickadees (Parus 

spp.) and plain titmouse (Parus inormalus) and those dependent on seeds of pines and junipers for food. Some small 

mammals such as pinyon mice (Peromyscus truei) have been 

found in pinyon-juniper dominated stands and not in early 

seral communities (Sedgwick and Ryder 1987). Mature 

stands also provide hiding and thermal cover for mule deer 

USDA Forest Service Proceedings RMRS-P-9. 1999 

(Odocoileus hemionus) and elk (Cervis canadensis). However, without forage openings, pinyon-juniper ecosystems 

are oflow value for deer and elk and thus for large predators 

such as cougars (Felis concolor). Also high val ues for fuelwood 

and fenceposts are associated with mature pinyon-juniper 

stands. Some recreational activities (picnicking and summer camping) are greatly facilitated by shade of mature 

stands. 

Bighorn sheep (Ovis canadensis) in the Green River corridor strongly favor early seral stages without visual obstructions of trees and tall shrubs (Smith 1992; Greenwood and 

others, these proceedings). However, these sheep also prefer 

steep slopes with a presence of cliffs and ledges that they use 

to escape predators. Thus, early seral communities in and 

adjacent to this essential escape habitat have high value for 

bighorn sheep while such communities at a distance from 

this essential escape terrain have low value. Pronghorn 

antelope (Antilocarpa americana) are also ungulates of open 

places that avoid cover of woodlands and forests. However, 

in contrast to bighorn sheep, pronghorn prefer low gradient 

plains and plateaus. Pronghorn have also responded positively to early seral communities maintained by fire within 

the Green River corridor. Sage grouse (Centrocercus urophasianus) highly favors shrub/grass/forb communities. As 

pinyon -juni per replace sagebrush communities, habitat val ue 

for these birds is greatly decreased. Some small mammals, 

such as deer mice (Peromyscus maniculatus), are more 

common in early successional communities (Sedgwick and 

Ryder 1987). The abundance ofthese animals can be important to birds of prey and other predators. 

Value of yearlong and especially winter range for elk and 

mule deer is greatly increased by the presence of shrubs wi th 

stature that exceeds snow depths and have higher levels of 

protein and other nutrients than do grasses and forbs in 

winter. Highest value deer and elk range includes shrub/ 

grass and shrub/open tree communities or mid seral stages 

intermingled with patches of mature trees that provide 

thermal cover. Although some birds prefer mature pinyonjuniper communities, others including hawking or foliage 

gleaning, cup-nesting insectivores such as the blue-gray 

gnatcatcher (Polioptila caerulea), black-throated gray warbler (Dendroica petechia), and gray flycatcher (Empidonax 

wrightii) (Ehrlich and others 1988) are favored by presence 

of shrubs. Vesper sparrow (Pooecetesgramineus) and Lazuli 

bunting (Passering amoena) are also associated with mountain shrub species of mid seral communities. Also birds 

typical of sagebrush formations are also found in stages with 

an abundance of sagebrush such as the sage sparrow 

(Amphispiza belli) and Brewer sparrow (Spizella breweri) 

(Behle 1981). A shrub component can increase abundance of 

insects used by many bird species including jays (often 

considered seedeaters) to feed their nestlings. 

Trees most likely to be selected for Christmas trees are 

most likely to be found in shrub/open tree and tree/shrub 

communities. 

Seeds of pinyon and juniper have value for a number of 

wildlife species including birds ofthe Corvidae family (Balda 

1987). Pinyon nuts have value for personal and commercial 

use. Generally, seeds are not part ofthe sere until the shrub/ 

open trees stage. They are most abundant in the tree/shrub 

and mature pinyon-juniper stages. 

Recreation and visual values can be expected to vary with 

individuals and their various activities. Bird watching and 

167 
study of birds are indicated to be at highest value in tree/ 

shrub and mature stages. Viewing and hunting bighorn 

sheep, elk, deer, and antelope will be facilitated by maintenance of early and mid seral communities. Personal use 

Christmas tree harvest is a form of recreation for which 

shrub/open tree and tree/shrub stages are of highest value. 

Visual qualities can be expected to be highly variable with a 

diverse viewing public. Perhaps a diversity of stages across 

the landscape will address this value. Sometimes values 

expressed by humans run opposite to those favorable for 

some wildlife species. People often object to standing dead 

trees left after fire. However, these dead trees provide some 

cover and structure for wildlife. Also, this human view is not 

well supported by the ecological history of pinyon-juniper 

ecosystems that included standing, burnt trees. Objections 

are also expressed for the blackened and desolate look 

following fire and the broken debris- following mechanical 

treatments. However, habitat for early and mid seral wildlife and plant species cannot be maintained without treatments t~at reduce trees. The debris left in place following 

mechamcal treatments can have high value for watershed 

protection (Farmer 1995). 

Erosion hazard is related to successional stages. In the 

perennial grass/forb stage and midseral stages, the ground 

IS covered by many fine stems of vegetation that are closely 

spaced and by litter that has a high dispersion value. Mature 

pinyon-juniper stands tend to have large interspaces of high 

percent bare ground. This condition is especially noticeable 

on steep, southerly (warm) exposures in the Green River 

corridor (Goodrich and Reid, these proceedings). The warm 

aspects have potential for higher value for mule deer and elk 

forage in winter than cool exposures due to less depth and 

duration of snow cover. However, mature stands have much 

lower value for forage for these animals than do early and 

mid successional stages. Thus, both watershed and ungulate 

forage values for these slopes can be higher at early and 

midseral stages than at the mature stage. 

Vigor and diversity of understory communities remains 

quite high thorough the shrlJb/open tree stage and then 

declines thorough the tree/shrub stage, and it is greatly 

reduced in the mature stage (Huber and others, these 

proceedings). Vigor of the understory community is critical 

t~ the resilience of native plant communities following 

dIsturbance. Recovery of native communities can be quite 

rapid following fire in the perennial grass/forb through the 

shrub/open tree stages. Recovery of native plant communi-

~ies. is much slower following disturbance in mature pinyonJumper communities. This feature of pinyon-juniper woodlands h~s become critical with the advent of cheatgrass, 

musk thIstle, and other highly invasive introduced species. 

COl~pled with the nature ofpinyon-juniper to greatly oppress 

native understory species and outlive the seed banks of 

these species (West and Van Pelt 1987), the explosive ability 

of cheatgrass to increase after disturbance (Young and 

Evans (1978) presents a scenario in which it is difficult to 

apply a concept of native plant communities. Disturbance is 

us ually a matter of "w hen" more than of "if." When disturbance comes to mature and old stands of pinyon-juniper, the 

stands are left wide open to the invasion of cheatgrass and 

other invasive weeded species by the general lack of native 

understory species, which is a function of pinyon-juniper 

stand closure (Everett 1987; West and Van Pelt 1987). 

168 

Diverse plant communities develop in early and mid seral 

stages of succession where in dense mature stands of pinyonjuniper understory communities are often of low diversity 

and members of these communities are of low frequency. 

However, mature and old stands provide structural features 

not found in earlier stages. 

Intrinsic values are sometimes raised as an issue. Each 

plant community has intrinsic value, and the value of each 

stage can vary widely within a diverse public. This ambiguous value is included in the other more specific values 

addressed above. 

Ecological Units 

Management for diversity of values will be well served by 

an understanding of capabilities. Hironaka (1987) suggests 

the trees themselves do not provide a bases for classification 

and their suppression of understory species often prohibit~ classification based on the understory. Classification, inventory, and documentation of community features based on 

more than the end point of a sere are critical to understanding values and capabilities. 

A Land Systems Inventory has been developed for part of 

the Green River corridor based on geology and geomorphology with gradient, aspect, soils, vegetation, and other features also used as descri ptors of ecological uni ts (Wertz and 

Arnold 1972). Classification is an inherent part of this 

inventory. The inventory also includes some information on 

capabilities and values of different ecological units. As more 

information is acquired through studies, research, observations, and experience, this is added to the inventory. Such a 

"living inventory" seems vital to adaptive management. 

This paper and other papers referenced in this paper dealing 

with the Green River corridor can be used as a part of the 

database of the Land Systems Inventory. 

Managing for various values can be greatly facilitated by 

information about the capabilities of various land units 

within a landscape. Without specific examples this concept 

seems to remains rather empty. Thus, specific examples 

from the Green River corridor are used in the following 

discussion. 

In this area, soils, vegetation, visual values, and wildlife 

habitat are much a function of geologic features. These 

features are basic to an evaluation ofland capabilities. Basic 

to management of the pinyon-juniper belt is the considera tion of how much of each successional stage is desired and 

where on the landscape these stages should be emphasized. 

A equal portion of each stage or some other mix of stages as 

suggested by Amundson (1996) may be satisfactorily defined 

in a conceptual or programmatic manner without considering where on the landscape each stage is to be emphasized. 

However, a random assignment of succession stages to 

actual parts of the landscape without regard to inherent 

capabilities of different ecological units within the landscape does not appear to be the most effective way to achieve 

a desired mix. 

An evaluation of lands within the context of the Land 

Systems Inventory indicates different successional stages 

may be more appropriate for different land units. Based on 

a dominant feature of ridge and ravine topography as a 

function of differential weathering of geologic strata at the 

USDA Forest Service Proceedings RMRS-P-9. 1999 
flank of the Uinta Mountain uplift, a landtype association 

referred to as "Structural Grain" was identified in the Land 

Systems Inventory. The Red Canyon gorge of the Green 

River was identified as "Red Canyon" LandtypeAssociation. 

Nearly all of the Structural Grain Landtype Association and 

southerly exposures of the Red Canyon Landtype Association support pinyon-juniper communities or have the capacity to do so. Landtypes within these associations have been 

identified by number. This inventory is consistent with the 

concept of ecological units as defined within a National 

Hierarchical Framework of Ecological Units that has been 

adopted by U.S. Department of Agriculture, Forest Service 

as discussed by McNab and Avers (1994). They also fall 

within the concepts of Godfrey (1977), Godfrey and Cleaves 

(1991), and Wertz and Arnold (1972). A discussion of all 

ecological units identified for the pinyon-juniper belt of the 

Green River corridor is beyond page limitations for this 

paper. Following are three examples ofthese ecological units 

and management implications based on capabilities and 

values. 

Structural Grain Landtype 2 Ecological 

Unit 

Features-The landtype consists of ridge and ravine 

topography underlain by the Uinta Mountain Group, which 

includes shale and quartzitic sequences. The shale and other 

more easily eroded units have been eroded to produce the 

ravines, while the more resistent beds form ridges. The 

ridge/ravine sequence has a general east-west direction with 

northerly (cool) and southerly (warm) exposures of about 20 

to 40 percent slope. The shrub/open tree stage of the cool 

exposures incl udes alder-leaf mountain mahoganylbluebunch 

wheatgrass communities with as high as 40 or more herbaceous plant species and often five or more shrub species 

(Huber and others, these proceedings). Within the Green 

River corridor, this diverse community is nearly unique to 

the Structural Grain Landtype Association. Earlier stages 

of succession on southerly exposures su pport Indian ricegrass, 

bluebunch wheatgrass, and a few other herbaceous species 

followed by mountain big sagebrush and rubber rabbitbrush. Seral communities of both cool and warm aspects can 

be essentially purged under mature stands of pinyon-juniper. The soil surface of cool aspects is well mantled by 

vegetation and litter through the shrub/tree stage and often 

by a layer of duff under the dense canopy of mature pinyonjuniper. The soil surface of warm aspects is moderately to 

highly protected by vegetation and litter in the perennial 

grass/forb through the shrub/open tree stage. However, as 

pinyon-juniper increase, the understory is depleted and 

ground cover decreases to the duff found under the canopies 

of trees with the interspaces nearly barren. Low watershed 

values can be associated with mature and old pinyon-juniper 

stands on the warm aspects (Goodrich and Reid, these 

proceedings) . 

These warm slopes can have comparatively high value for 

wild ungulate forage in winter because depth and duration 

of snow cover is less here than on cool exposures. However, 

the shrub stages of the cool exposures also have high value 

for wintering wild ungulates due to the abundance of taller 

shrubs including alder-leaf mountain mahogany and serviUSDA Forest Service Proceedings RMRS-P-9. 1999 

ceberry. Much of the landtype is far enough removed from 

high value bighorn sheep escape terrain that it generally has 

low value for these animals. However, parts ofthe landtype 

are close enough to escape terrain to be of high value for 

bighorn sheep. 

Management Implications-The diversity and uniqueness of shrub/grass and shrub/open tree stages indicate high 

value for maintaining these stages on this land type. These 

communities have high value for wintering mule deer and 

elk and for some birds and small mammals favored by 

shrubs. Long-term occupancy of mature pinyon-juniper 

stands deplete and eventually purge the understory. Where 

shrub/open tree communities are now present on the landscape, maintenance of the understory is indicated as high 

priority for management. Maintenance will require fire or 

other disturbance that reduces trees before shrubs, grasses, 

and forbs lose the ability to rapidly recover. Some stands 

where the understory is already purged include large boles 

and crowns in the structure. These serve to provide overall 

diversity and values associated with mature stands. 

The apparent high value for winter forage for wild ungulates of early to mid successional stages of the warm, southerly exposures coupled with the erosive nature of some of 

these slopes under mature pinyon-juniper indicate high 

value for perennial grass through the shrub/open tree stages. 

Capabilities and values of this ecological unit strongly 

indicate primary emphasis for early to mid seral communities. This emphasis should not preclude some mature stands. 

A fire return interval of 100 to 150 years is indicated to 

maintain these seral stages (Goodrich and Barber, these 

proceedings) . 

Structural Grain Landtype 7 Ecological 

Unit 

Features-High frequency of scarp and dip slopes is 

typical of the landtype. The scarp slopes (of southerly exposure) often include cliff faces. The dip slopes (of northerly 

exposure) frequently have bed rock at or near the surface. 

Many pinyon-juniper trees are large and 200 to 300 years 

old. Some are over 400 years old. Understory vegetation is 

sparse. The highly diverse mountain brush com~unities ~f 

Structural Grain Landtype 2 are generally lackmg on thIS 

landtype. However, bitterbrush is often present, and it 

increases with reduction in tree cover. 

Currently nearly all of this ecological unit supports mature and old stands of pinyon-juniper. Ponderosa pine (Pinus 

ponderosa Laws.) is also occasionally to locally common on 

the landtype, which provides another layer of canopy a~d 

another dimension to woody structure. Large trees of pmyon, juniper, and ponderosa pine indicate high value for 

cavity nesting species. The large crowns and diverse layers 

of canopy provided by these trees indicate high value for 

many bird species and some small mammals. High percent 

rock at the soil surface and in the profile provide stable 

watershed conditions under mature stands of trees. A large 

unit of the landtype is adjacent to Flaming Gorge Dam. It is 

dissected by a National Scenic Highway (Highway 191) and 

by power transmission corridors. It is also near the town of 

169 
Dutch John. These features indicate difficulty for prescribed 

burning and other management practices. 

Management Implications-Inherent and imposed features of this ecological unit strongly indicate emphasis for 

mature and old stands. Old trees on the landtype indicate a 

fire return interval of greater than 200 years to be an 

inherent part of the ecological history of the landtype. 

Increased recreation use associated with Flaming Gorge 

Reservoir presents a higher potential for fire than that 

under which these stands developed. Fire suppression could 

be helpful and seems appropriate in maintaining greater 

than a 200 year fire return interval. 

Red Canyon Landtype 1 Ecological Unit 

Features-The gorge of Red Canyon carved by the Green 

River is the prominent feature of this landtype. It includes 

massive cliffs of Pre cambrian q uartzitic materials and shales 

of the Uinta Mountain Group. Also included are steep, rocky 

slopes of mostly greater than 40 percent slope. Southerly 

(warm) exposures dominate the landtype. Daytime temperatures well above freezing are common in midwinter on 

some of these slopes. Abundance of escape terrain and 

aspects that are warm in winter indicate high value for 

bighorn sheep. Smith (1992) and Greenwood and others 

(these proceedings) found warm aspects of Red Canyon to be 

highly selected by bighorn sheep. Such aspects are also 

conducive to abundance of cheatgrass (Goodrich and Gale, 

these proceedings). The winter annual habit of cheatgrass 

indicates high forage value of this plant for bighorn sheep. 

These sheep have been observed in winter on the landtype 

with green muzzles from feeding on wintergreen cheatgrass. 

However, cheatgrass does not provide nutritional needs in 

all seasons ofthe year. Maintenance of a diverse forage base 

will better meet the needs of these animals. Timely use offire 

and seeding perennial species are important to maintain a 

balanced forage base. Evidence of past fire is common on the 

landtype. However, in many places rock cover is high and 

density of vegetation is sparse. In these areas fire frequency 

and size are expected to be low due to rock cover. 

Management Implications-Pinyon and juniper have 

the ability to displace all other plant communities in the 

absence of fire or other disturbance. The high value of this 

landtype for bighorn sheep indicates emphasis for early 

seral communities with low presence oftrees and tall shrubs. 

A fire return interval of less than 80 years is indicated for 

achieving and maintaining high value habitat for bighorn 

sheep. 

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171 
Watershed Values and Conditions 

Associated with Pinyon-Juniper 

Communities 

Bruce A. Roundy 

Jason L. Vernon 

Abstract-Pinyon-juniper watersheds are important seasonal 

transition areas for grazing and wildlife habitat. Tree control to 

improve habitat and hydrologic responses have been questioned 

because low precipitation, high evapotranspiration, and coarse 

surface soils of many sites suggest that runoff, erosion, and 

subsurface water yield should be minimal anyway. Lack of measured data and highly variable site conditions prevent applying 

these generalities to all sites. Invasion sites with high soil erosion 

potential may quickly degrade when a small decrease in interspace 

vegetation cover and water storage capacity increases connectedness of runoff pathways during intense summer thunderstorms. 

Tree control practices which leave downed trees and debris in 

place and increase interspace vegetation cover may help save such 

sites from permanent degradation. 

Pinyon (Pinus spp.) and juniper (Juniperus spp.) plant 

communities have been of major interest from a watershed 

stand point because of their extensive distribution and 

location in the semiarid Intermountain West. Variations of 

these communities are distributed on about 30 million 

hectares mainly across Arizona, Colorado, Nevada, New 

Mexico, Texas, and Utah, with lesser distributions in California, Idaho, and Oregon (West and others 1975). Their 

wide range elevationally from about 1,000 to 3,000 m and 

topographically on alluvial f:;lns and bajadas, foothills, 

terraces, mesas, and mountain slopes (West and others 

1975; Evans 1988) has made these communities extremely 

important for their resource values. Watershed concerns 

and values center around 1) their importance as transitional areas for livestock forage and wildlife habitat, 2) 

their potential for water yield, 3) the effects of their potential surface runoff and sediment on downslope, offsite 

values, and 4) their potential onsite erosional degradation. 

These lands are transitional between lower elevational 

lands that are topoedaphically more arable under irrigation and higher elevational mountain shrub and coniferous 

forest lands with more dependable precipitation. This extent and topographic position results in significant economic value of these lands for spriGg-fall livestock grazing 

and for winter range of big game such as mule deer 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Bruce A. Roundy is Professor of Range Management and Jason L. Vernon 

is Research Assistant, Department of Botany and Range Science, Brigham 

Young University, Provo, UT 84602. 

172 

(Odocoileus hemionus) and elk (Cervus elaphus) and has 

led to vegetation manipulations to improve these values 

(Roundy 1996). There has been a major concern over the 

hydrologic and ecological impacts of these vegetation 

manipulation practices. 

Droughts in the 1950's led to studies to increase water 

yield from pinyon-juniper woodlands and other forests 

(Wilcox 1994). Such potential has been strongly questioned 

for pinyon-juniper lands because of their low precipitation. 

Also, the location of these woodlands on slopes just above 

alluvial fans and valleys with more gentle slopes has made 

them sources of flooding and debris flows from summer 

thundershowers to some ofthe towns in the Intermountain 

area located at the base of these slopes (Stevens 1997). A 

major large-scale off-site concern for the hydrology of these 

lands is their potential contribution to salt and sediment in 

the Colorado River drainage (Rasley and Roberts 1991). 

There is also a major concern for the onsite erosional 

degradation ofthese woodlands and especially former grass 

and shrublands downslope considered to be invaded by 

these trees in the absence of fire. These lands have a 

semiarid climate with 200 to 500 mm annual precipitation 

in the form of winter snows and light rains but also potentially-intense summer thunderstorms (West and others 

1975). Therefore, the nature of the precipitation, seasonal 

aridity, surface hydrology, and soil moisture are the major 

determinants of interacting ecological and hydrological 

processes. As in many other seasonally dry plant communities world wide, fire occurs as a natural disturbance and its 

frequency and successional timing have a major affect on 

vegetation dynamics (Wright and Bailey 1982). The precipitation on many of these lands is inadequate to produce 

high plant cover, but is of sufficient intensity during summer thundershowers to produce localized runoff and erosion (Baker and others 1995). The composition and structure of these plant communities relative to hydrologic 

function is therefore an extremely important concern to 

land managers who want to preserve soil resources as the 

basis for all other values. 

In this paper, we review the hydrology of pinyon pine and 

juniper lands relative to their function and ecology and 

discuss watershed responses to vegetation manipulations 

as a basis for more informed management of these lands. 

Hydrologic Relationships ___ _ 

The hydrology of pinyon and juniper watersheds is a 

function ofthe precipitation amount, intensity and seasonality, the geology as it relates to topography, subsurface 

porosity, and surface soils, and understory-overstory 

USDA Forest Service Proceedings RMRS-P-9. 1999 
vegetation dynamics as affected by disturbance regime. 

Because pinyon and juniper compositional variants occur 

across a wide range of climatic conditions and elevations, 

they also vary widely in the interaction ofthese major factors 

and therefore in their hydrology (Hawkins 1987). Common to 

the hydrology of many of these communities when trees are 

dominant are a relatively high evapotranspirational component of the water budget (fig. 1) and high exposure of surface 

soils between trees that are potentially major sources of runoff 

and erosion. However, a lack of hydrologic data in general 

(Schmidt 1987), and lack of data for specific sites 

requiresthatmanagement-oriented predictions of hydrologic 

responses for a given site be based on a good understanding of 

the interaction of these major factors. 

Geology and Physiography 

An understanding of the geological substrate, including 

it's effect on surface soil and associated infiltration, it's 

effect on soil fertility and associated vegetation dynamics, 

and it's subsurface porosity and associated effects on drainage and water yield are essential in understanding pinyonjuniper site hydrology. The Basin and Range and Colorado 

Plateau physiographic provinces contain over 70 percent of 

Evapotranspiration 

68-96% 

the land area occupied by pinyon andjuniper communities 

(West and others 1975). Geologic parent materials consist 

mainly of sedimentary rocks such as limestones, dolomi tes, 

shales, and sandstones, formed from Paleozoic, Mesozoic 

and Cenozoic sediments, and igneous rocks from Tertiary 

and Quaternary vulcanism (Hunt 1967; Hintze 1988). 

In the Basin and Range province, pinyon and juniper grow 

on the shallow rocky slopes and escarpments ofthe mountain 

ranges, as well as on lower mountains, foothills, and depositional areas. In the Great Basin, these mountains were block 

faulted during the Tertiary and Quaternary periods and are 

mainly complexly deformed Paleozoic sedimentary rocks of 

limestone, sandstone, siltstone, and shale (Hunt 1967). Some 

of the mountain ranges formed from Precambrian metamorphic rocks of gneiss, schist, and quartzite, or, in some cases, 

Precambrian sedimentary deposits. 

Tertiary vulcanism produced localized granitic intrusions in the Basin and Range Province, as well as in the 

Colorado Plateau. Examples of these igneous intrusions in 

the form of stocks and laccoliths into older sedimentary 

layers include the Henry, Abajo, and La Sal Mountains in 

southeastern Utah (Stokes 1988). Tertiary vulcanism also 

produced major extrusive igneous rocks in the form of 

basalt flows and cinders as well as rhyolite flows, ash or 

Interception 

17-290/0 

~------------------~ 

Runoff 

1-23% (usually 

4 to < 8%) 

Deep 

Seepage 

0% 

Change in 

Soil Moisture 

Storage 4-6% 

Figure 1-Hydrologic budget components of pinyon and juniper watersheds from estimates or 

compilations of Gifford (1975), Young and others (1984), Hawkins (1987); Lane and Barnes (1987), 

Eddleman and Miller (1992), and Wilcox (1994). 

USDA Forest Service Proceedings RMRS-P-9. 1999 173 
breccia (Stokes 1988; Hintze 1997). These volcanic materials make up many of the mountain ranges in the Basin and 

Range Province in south central Nevada, and include major 

areas where the Basin and Range and Colorado Plateau 

Provinces meet in Arizona and especially in south central 

Utah (Hintze 1997). Quaternary vulcanism associated with 

Basin and Range faulting has also produced localized lava 

flows and cinder cones (Chronic 1990). 

Pinyon and juniper woodlands are found on the mesas, 

foothills, breaks, mesa edges, escarpments and depositional areas of the Colorado Plateau (Dortignac 1960). The 

predominate sedimentary rocks of the plateau formed from 

vast inland seas or sandy deserts during the Paleozoic and 

Mesozoic eras, and also from depositions in large, freshwater lakes during the early Tertiary period (Stokes 1988). 

Because of highly varied geology and physiography, pinyon and juniper communities occur across a wide range of 

surface soils from stony, cobbly, and gravelly sandy loams 

to clay loams (Springfield 1976). An analysis of 100 soil 

surveys in Nevada, New Mexico, and Utah indicated that 

various species of pinyon and juniper occur on almost all 

textural groupings (Leonard and others 1987). The predominant textural groups in the particle size control section of the profile were coarse loamy and fine loamy and 

surface horizons were predominately gravelly or stony. Soil 

depth ranged from < 0.5 to > 1.5 m- deep but were shallower 

for soils described in Nevada and Utah compared to New 

Mexico. Leonard and others (1987) suggested that soils in 

New Mexico were described for all occurrences of pinyon 

and juniper while soils in Nevada and Utah were only 

described for shallow or skeletal sites with lower understory production and less fire potential. This study helps 

confirm that pinyon and juniper distribution is not necessarily limited by soil texture, stoniness, or depth, and 

suggests that a knowledge of the soils on a site is necessary 

for appropriate management (table 1). 

Hydrologic Componel1ts 

The great variability in soils, geological substrate, slopes 

and precipitation patterns make it difficult to uniquely 

characterize pinyon and juniper communities hydrologically (Hawkins 1987). Schmidt (1987) has lamented the 

lack of hydrologic data for pinyon and juniper watersheds 

and the misapplication of existing site-specific data to 

support general conclusions. It appears that the reverse is 

also true, sometimes generalizations are used to conclude 

or predict responses on specific sites. Wilcox (1994) summarized watershed and hillslope studies of the 1960's and 

1970's, most of which were set up to evaluate the effects of 

vegetation manipulation on runoff and water yield. He 

concluded that in general, evapotranspiration is the major 

process of water loss; that runoff is less than 10 percent of 

the water budget; that streamflow is ephemeral and generated by intense summer thunderstorms, prolonged frontal 

storms, and melting snow; and that groundwater recharge 

is limited due to high evapotranspiration. The temporal 

and spatial variability of data in Wilcox's (1994) own study 

in New Mexico led him to state that hypotheses proposed for 

other semiarid systems are also true for pinyon andjuniper 

woodlands. These include that runoff varies with scale and 

decreases as the size of the contributing area increases, 

that infiltration capacity is seasonally dynamic and highly 

dependent on soil moisture content and frost, and that 

erodibility follows the seasonal infiltration capacity. 

Rangeland watershed research has shifted emphasis 

from measuring effects of management treatments to measuring processes at a range of relevant scales in order to 

more accurately predict hydrologic responses (Blackburn 

and others 1994). Research of this magnitude and intensity 

has been recommended for the pinyon and juniper zone 

(Schmidt 1987). Dobrowolski (1997) is setting up multiscale 

studies on juniper sites in the Clover Creek area of the 

Onaqui Mountains in Utah. Similar studies are under way 

at the Los Alamos National Laboratory's Environmental 

Research Park in north-central New Mexico (Wilcox 1994; 

Wilcox and others 1996a; Davenport and others 1998). 

Such studies are important, since watershed responses 

involving interactions among time, land, and water input, 

transport, and output processes do not scale up linearly 

(Hawkins 1987). 

Because oflow precipitation, Hawkins (1987) characterized 

pinyon and juniper hydrology as dominated by surface phenomena. He concluded that 95 percent of the precipitation 

becomes soil moisture, much of which is lost to evapotranspiration. Other authors have also characterized the hydrologic 

Table 1-Geologic parent materials and properties of soils associated with 

pinyon-juniper communities in Arizona and New Mexico (Springfield 

1976). 

Infiltration Moisture holding 

Parent material capacity capacity Fertility 

Jurassic sandstones High Low Low 

Supai sandstones Medium Medium Low 

Coconino sandstones High Low Low 

Kaibab limestone High Low Low 

Redwall limestone Medium Medium Medium 

Triassic shales Low High Low 

Mesa Verde formation Medium Medium Medium 

Tertiary volcanics (basalt) Medium High High 

Quaternary volcanics Medium to high Low to high Low to high 

Granite High Low Low 

Sand and gravel High Low Low 

174 USDA Forest Service Proceedings RMRS-P-9. 1999 
budget as being dominated by interception and 

evapotranspirational water losses, with little water left 

over for runoff or deep drainage (fig. 1). Newman and others 

(1997) found that soil water evaporation was mainly from 

the upper 10 cm of soil in both ponderosa pine (Pinus 

ponderosa) and pinyon -j uni per communities in New Mexico. 

Hawkins (1987) considered storm runoff from pinyon-juniper communities to be rare and limited in volume. He 

expected that limited runoff, combined with the usual stony 

surfaces of pinyon and juniper land would produce modest 

erosion. He also went through a major exercise to show that 

some applied hydrological methods widely used by land managers were inaccurate for predicting responses under conditions of threshold runoff, especially when local data were 

lacking for calibration. It is important to point out that, 

although some studies have measured various hydrologic 

variables such as precipitation, interception, soil water change, 

and even runoff, no studies have carefully measured all 

components of the hydrologic cycle on a specific pinyonjuniper site. Thus estimates of high evapotranspiration, ~ow 

runoff, and limited deep drainage may make sense, but are not 

backed up by needed measured data over a range of scales on 

different sites and geological substrates. 

While the generalizations may apply, there are still cases 

oflocalized runoff, erosion, downstream flooding, and deposition from pinyon and juniper watersheds (Stevens in 

press). For example, the town of Manti, Utah historically 

never developed on the southern end because of frequent 

flooding and deposition from upslope pinyon and juniperdominated drainages (Stevens 1997). Other towns in the 

Great Basin, such as Ely, Nevada have experienced similar 

flooding from surrounding pinyon and juniper watersheds. 

Pinyon and juniper landscapes are subject to high-intensity summer thunderstorms (Schmidt 1987). Even if these 

rarely occur, they can cause considerable damage when 

they do occur. In the absence of hydrologic measurements 

for specific sites, application of generalizations, rather 

than an understanding of hydrologic interactions for the 

specific site can lead to incorrect management predictions 

and decisions. 

A component of the hydrologic budget that has often been 

overlooked for semiarid watersheds is interflow (Wilcox 

and Breshears 1997) . Where the combination of sufficient 

precipitation (usually over 450 mmiyear), and an impermeable layer create a zone of saturation, the resulting interflow 

may be a source for streamflow (Wilcox and Breshears 

1997). Downward movement of water through the soil 

profile was much less for a ponderosa pine site with a clayey 

subsurface soil horizon than it was for a nearby pinyonjuniper site with lower subsoil clay content (Newman and 

others 1997). Although low precipitation and high evapotranspiration of pinyon-juniper communities generally results in very little deep groundwater recharge, there may 

still be many sites where a shallow impermeable layer 

allows short seasonal saturation and sufficient interflow to 

feed local springs and streams. 

While sophisticated models for wildland hydrology 

prediction are being developed, a simple conceptual model 

may help to explain the response of pinyon and juniper 

woodlands to intense thunderstorms and help to guide management decisions. This conceptual model has been used to 

illustrate the relationship of wind and water erosion to bare 

USDA Forest Service Proceedings RMRS-P-9. 1999 

ground and vegetation cover (Branson and others 1981). 

Baker and others (1995) recently applied a modified form of 

this model (Heathcote 1983) to pinyon and juniper lands. 

The model shows a major potential increase in water 

erosion of bare surfaces compared to those with vegetation 

cover where annual precipitation exceeds 400 mm. The 

important point is that annual precipitation for the pinyon 

and juniper zone is insufficient to produce enough vegetation cover to prevent erosion, but is sufficient, especially 

with short-term thunderstorms of high intensity (Schmidt 

1987) to produce water erosion. Therefore the amount and 

type of soil cover and the soil-holding abili ty of root systems 

are major determinants of erosion control for these areas. 

Wood (1988) has explained how pattern and density, in 

addition to cover of vegetation in semiarid areas have a 

major effect on infiltration and erosion. He suggested that 

for a given plant cover, a greater density and perhaps 

dispersion of plants offers greater soil protection. Large, 

bare, connected interspaces between trees have much lower 

infiltration rates than tree mounds and can become major 

source areas for sediment and pathways for runoff. Wilcox 

and Wood (1989) also determined that vegetation cover, 

especially that of shrubs, was important in decreasing 

interrill erosion. Lack of cover and organic matter inputs, 

coupled with raindrop impact may result in low aggregate 

stability and the formation of surface crusts with low 

infiltration rates on semiarid interspace soils (Blackburn 

1975; Roundy and others 1990). In contrast, subcanopy 

inputs from drip and stem flow (Young and others 1984) 

should be expected to infiltrate the well-aggregated, littercovered soils beneath the trees (Blackburn 1975; Roundy 

and others 1978) unless stopped by an excessive unwettable 

layer (Scholl 1971). Davenport and others (1996) found 

little difference in soil morphological properties between 

interspace and canopy areas on a rhyolitic pinyon-juniper 

site in New Mexico. This suggests that runoff-erosion responses in pinyon-juniper communities are not associated 

with the physical effects of tree roots on soil morphology, 

but rather a result of biological interactions (Breshears and 

others 1997). Although it has been difficult to measure, 

determination of hydrologic source-sink relationships for 

canopy and interspace zones is needed to better understand 

pinyon and juniper runoff and soil movement at the landscape scale (Wilcox and Breshears 1995). 

Wilcox and Breshears (1995) suggested a conceptual 

framework, scales, and functional units and hypotheses of 

hydrologic differences and connections for each scale for 

field studies of pinyon-juniper woodlands and other semiarid systems (fig.2). At the woodland, intercanopy, and 

herbaceous patch scales, they hypothesized that most runoff and erosion would come from interconnected, bare 

interspaces, but that herbaceous patches could serve as 

sinks for water and sediment. This framework serves well 

to organize future hydrologic research on semiarid lands. 

Davenport and others (1998) have integrated many of the 

foregoing ideas into a conceptual model of soil erosion in 

pinyon-juniper systems. Their work in New Mexico (Wilcox 

and others 1996a; 1996b) suggests that soil erosion for a 

site is a product of the interaction of soil erosion potential 

(SEP, a function of climate and edaphic factors) and cover 

conditions. A threshold of accelerated erosion occurs when 

ground cover in intercanopy areas is reduced to the point 

175 
Mesa top 

Herbaceous 

patch scale 

I 

Plateau scale 

North 

Woodland scale 

Figure 2-Conceptual model of hydrologic 

processes for the Pajarito Plateau showing 

functional units at each scale (WilCOX and 

Breshears 1995). 

176 

Intercanopy scale 

Herbaceous 

patches Bare 

patches 

that precipitation runs off through connected interspaces 

when storage capacity is exceeded. For sites with high SEP 

due to such factors as fine soil texture, high rainfall intensity, and higher slopes, a small reduction in intercanopy 

ground cover can result in substantially accelerated erosion. Davenport and others (1998) suggested that the range 

of site conditions associated with high SEP are limited for 

the pinyon-juniper woodland, but that sites with these 

particular conditions could cover large areas. 

Vegetation Dynamics 

Fire occurs in pinyon and juniper communities when 

there is sufficient understory to carry it from tree to tree, or 

when tree canopies "close up" enough for fire to spread from 

crown to crown (Lotan and Lyon 1981). The ability of 

evergreen pinyon andjuniper trees to slowly and efficiently 

accumulate carbon by more active year-round photosynthesis than associated herbs and shrubs, coupled with their 

tree growth form, allows them to build large above and 

below ground structures for resource capture (Johnsen 

1962; Tausch and Tueller 1977; Evans and Ehleringer 

1994; Martens and others 1997; West in press). Under 

semiarid conditions, much of the limited precipitation is 

taken up by the extensive root systems of the trees (Foxx 

and Tierney 1987; Evans 1988) and transpired through 

their canopies. Recent research of Breshears and others 

(1997b) has shown that shallow soil layers between tree 

canopies can be wetter than canopy areas when canopies 

receive less precipitation due to interception. Breshears 

and others (1997a) also determined that pinyon and especially juniper trees depleted soil moisture in intercanopy 

areas and that they transpire through the winter (Breshears 

1993). The resulting lack of water and nutrient availability 

from tree-root exploitation of interspaces can result in 

eventual mortality of understory plants in absence of fire or 

other tree-killing disturbances. 

Prehistorically and historically the range of pinyon and 

juniper dominance has been controlled by climate and fire 

frequency (Miller and Wigand 1994). Ranges expanded 

with increasing winter precipitation and contracted with 

drier periods. Relict woodlands, tree age-class ratios, fire 

scars, and historical documents generally indicate that 

pinyon and juniper woodlands before European settlement 

were open, sparse savannahs or confined to rocky ridges 

and shallow soils such as low sage (Artemisia) flats where 

fine fuels were too low to carry fire. In some cases, native 

Americans set fires which may have controlled tree expansion (West in press). Tausch and others (1981) surveyed 486 

stands of pinyon and juniper in the Great Basin and found 

that trees were younger than 120 years in half of the stands 

and that the highest period of tree establishment for these 

stands occurred between 1870 and 1920 when settlement 

impacts were greatest. They also noted that expansion of 

trees was downward in elevation and that this expansion 

reduced understory fuels necessary to carry fires. This and 

numerous other studies and observations cited in reviews 

of pinyon and juniper succession (West 1984a; West and 

Van Pelt 1987) substantiate the role of fire in controlling 

pinyon andjuniper expansion from upland sites with naturally low fire frequency to lower elevational sites with 

deeper soils, higher understory production, and potentially 

USDA Forest Service Proceedings RMRS-P-9. 1999 
high fire frequency. The change in fire frequency came 

initially with heavy understory grazing and removal of fine 

fuels in the late 1800's to early 1900's, and subsequently 

with fire suppression after World War II (Miller and Wigand 

1994). It is important to understand the fire disturbance 

ecology ofpinyon-juniper and associated potential invasion 

sites downslope, because these invasion sites may behave 

hydrologically very different when domina ted by trees than 

when dominated by shrubs and grasses. Also tree-invasion 

sites may function differently hydrologically than treedominated, fire-safe sites upslope. 

Interactions 

Geologic substrate, soils, and climate interact with pinyon and juniper vegetation dynamics, which affect hydrologic responses and subsequent interactions. Geologic parent materials produce soils with different infiltration and 

water-holding capacities, and fertility (Springfield 1976, 

table 1). Slopes of Precambrian or Cambrian quartzite have 

shallow soils that support limited understory and limit 

canopy closure of trees. These may be fire-safe sites for 

pinyon and juniper as are other sites with shallow, rocky, 

and infertile soils. Tertiary and Quaternary volcanic soils 

with high fertility support the most rapid invasion of 

pinyon and juniper in the absence of fire (Harper 1997). 

Tree canopies may close up enough to allow crown fires on 

these soils long after loss of understory fuels. On these soils 

and other sites with fewer rocks where trees have matured 

and the understory seedbank is depleted (Koniak and 

Everett 1982), severe crown fires could open the community 

to annual weed invasion and permanently degrade the site 

(West 1984b; Billings 1994; West in press). Wind erosion 

(Baker and others 1995) may also degrade former pinyon 

and juniper communities when vegetation structure is lost 

as annual weeds dominate with high fire frequency. Where 

pinyon and juniper have invaded coarse-textured alluvial 

soils which once supported sagebrush steppe, interspace 

erosion may remove surface soils until an armor of rocks 

halts additional erosion. The associated loss of nutrients 

(Baker and others 1995), mycorrhizal fungi, cryptogams, 

and water-holding capacity on these soils can result in 

permanent loss of understory productive potential. These 

sites will not close up enough for crown fires to carry and 

will remain as degraded woodlands with very limited diversity and high potential runofffrom intense storms. On some 

sites subject to surface erosion, archaeological values may 

even be lost (Traylor and others 1990; Chong 1993). Rasley 

(1997) has even observed that tree-dominated sites with 

highly erodible soils from sandstone parent materials may 

erode enough to expose tree roots and endanger the persistence of the trees themselves. Tree dominance to the point 

of understory exclusion on finer-textured, shallow soils of 

sedimentary materials such as the Green River shales in 

central Utah, results in substantial runoff and erosion from 

interspaces (Farmer 1995). 

The subsurface water yield of burned pinyon and juniper 

sites mayor may not be higher than that of similar sites 

with much higher tree cover and evapotranspiration, depending on subsurface geology. Reduced evapotranspiration could produce increased flow from springs or streams 

associated with impermeable sedimentary layers below 

USDA Forest Service Proceedings RMRS-P-9. 1999 

fractured or permeable sedimentary rocks (Fetter 1988). 

Such increased flow is a function of total and effective 

precipitation in relation to surface and subsurface water 

budgets. Greater water yield from most forests can be 

expected when evapotranspiration is reduced through fire, 

logging or other tree reductions in areas of higher precipitation, although water yields have been highly variable and 

situation specific (Satterlund and Adams 1992). Generally, 

most pinyon and juniper communities have insufficient 

precipitation to increase water yield by decreasing evapotranspiration (Hibbert 1979). However, where there is a 

subsurface impermeable layer, reduced evapotranspiration after tree control could permit a zone of saturation and 

interflow to feed nearby springs and streams. Also, reduced 

evapotranspiration from pinyon and juniper zones receiving subsurface flow from higher elevations could increase 

water yield locally, given suitable geology. Fires above and 

within the upper juniper zone of the Clover Creek watershed in the Onaqui Mountains of Utah have resulted in new 

stream and spring flows (Dobrowolski 1997). These mountains are composed of sandstones, shales, quartzites and 

mainly limestone (Hintze 1997), and the annual precipitation in the upper juniper zone is about 450 mm. Juniper 

management and hydrology are important locally in this 

area, not only because juniper control provides forage, but 

also because increased freshwater subsurface flow may be 

necessary to prevent salt water intrusion into wells in 

western Rush Valley. 

Intrusive igneous and metamorphosed crystalline rocks, 

as well as some sedimentary layers, have little primary 

porosity and will not take in subsurface water unless 

fractured by faulting or other changes in crust pressure 

(Fetter 1988). Extrusive igneous rocks such as lava flows 

and cinder beds may have high porosity, while that of ash 

beds can be much less (Fetter 1988). Dortignac (1960) 

suggested that watersheds of sandstone would yield the 

most runoff while those of basalt would yield the least. 

Watersheds of deep consolidated sandstone in the Colorado 

Plateau take in water readily but produce little spring or 

stream flow. Deep deposits of volcanic ash or quartz sand 

produce large areas of coarse-textured soils in southwestern Utah and northwestern Arizona. Tree reductions on 

these deep soils and porous substrates should not be expected to increase stream or spring flows (Harper 1997). 

Some finer-textured deep volcanic ash and sedimentary 

soils in Utah readily take in water but hold most of it as 

surface soil moisture. Reduced tree transpiration on these 

soils would be expected to produce greater herbaceous or 

shrub growth with increased soil moisture availability, but 

not greater water yield (Harper 1997). Similar, but shallower soils, especially in areas of low precipitation, would 

be poor candidates for revegetation and should not be 

targeted for tree reduction programs. Where limestone 

substrates on gentle slopes have weathered to produce 

mature soil profiles with substantial clay, water-holding 

capacity is high and unless precipitation is higher than 500 

mm, increased streamflow should not be expected with tree 

removal (Harper 1997). 

Fractured deep rock cores of Cambrian quartzite or 

Tertiary volcanics have deep percolation that feed springs 

and streams. An example of the former are the Stansbury 

Mountains in Utah where such fractures produce the springs 

177 
on the east side of the range and the big springs in Skull 

Valley on the west side. Examples of the latter are Monroe 

Mountain and the Fish Lake Mountains in southern Utah. 

These geological situations have the greatest potential to 

increase spring and stream flow with tree removal and 

reduced evapotranspiration (Harper 1997). 

Pinyon and juniper associations with various understory 

species cover roughly 13 million hectares of the Colorado 

Plateau in the Colorado River drainage system (Hibbert 

1979; Bentley and others 1977). Some of these soils formed 

in place or as alluvial depositions from sandstone, siltstone, 

and shale sedimentary layers and are highly erodible. As 

part of the Colorado River Basin Rangeland Salinity Contro I Proj ect, an interagency, in terdisci plinary resource team 

evaluated a number of basins and watersheds that ultimately drain into the Colorado River (Rasley and Roberts 

1991; Rasley and others 1991a,b; Rasley and others 1996). 

They used a revision (Rasely 1991) of the Pacific Southwest 

Interagency Committee (PSIAC) system to estimate sediment yields on rangeland plant communities in the Colorado River drainage, including pinyon andjuniper communities. They suggested that a typical rangeland watershed 

would have 7 to 15 percent ofthe area in a severely eroding 

condition due to past or present management practices 

(Rasely and Roberts 1991). They considered that this erosion accounted for 75 to 90 percent of the accelerated 

sediment loads yielded to the Colorado River. Pinyon and 

juniper communities with little understory and large areas 

of bare ground were considered to be a major source of this 

sediment. Although these PSIAC estimations may make 

sense, they have never been checked against measured 

data from pinyon-juniper watersheds. 

Watershed Management of Pinyon 

and Juniper 

Pinyon and juniper lands have been subjected to a range 

of environmental and man-induced disturbances over the 

years. Imposed on the natural and native American-induced fire frequency and climatic fluctuations of the 

precontact period, came the grazing, logging, and fire control of western settlement after the mid 1800's (West in 

press). Effects of heavy grazing and fire reduction on loss of 

herbaceous forage and increases in woody vegetation led to 

the development of a variety of brush control and revegetation technologies applied especially to pinyon-juniper, sagebrush, and mesquite (Prosopis spp.)-dominated rangelands 

(Vallentine 1989). Chemical control of pinyon and juniper 

has been primarily used in northern Arizona and New 

Mexico (Evans and others 1975; Johnsen 1987; Baker 

1986). Mechanical methods have been used most extensively to control pinyon and juniper and, with prescribed 

fire, have the greatest potential effect on hydrologic variables (Blackburn 1983). 

Vegetation Manipulation Effects on 

Hydrology 

Effects of vegetation manipulation on hydrologic variables of pinyon and juniper communities have been reviewed by Clary and others (1974), Gifford (1975), Blackburn 

178 

(1983), Schmidt (1987), and Wilcox (1994), and will be only 

briefly summarized here. It is important to remember the 

kind and scale of measurements taken when interpreting 

and applying the results of any study. Drawing conclusions 

of response at a higher scale than that measured is risky. 

For example, conclusions about infiltration capacity at the 

intercanopy, woodland, or plateau (watershed) scales (fig. 

2) from infiltration rate measurements made at the patch 

scale could easily be incorrect since they do not account for 

the existence and interconnectedness of source-sink areas. 

Another caution is to remember the site and situationspecific nature of responses to vegetation manipulations. 

The interactions already mentioned of geology, soils, precipitation, vegetation dynamics, and resulting hydrologic 

responses are also greatly affected by management history, 

treatment practices and posttreatment management. This 

is one reason why natural resource management is a science and an art in practice and requires experience and 

familiarity with the specific environmental conditions and 

responses in specific management areas to be most successful. We are still far from the point of being able to accurately 

model responses to changing environmental conditions for 

the large range of sites of interest. Most lands have been 

subjected to a variety of grazing pressures and treatment 

procedures over the years. Responses on these sites over 

time and with changing management may differ greatly 

from measurements made during the first few years after 

a particular treatment. 

Watershed-scale studies conducted in Arizona at Beaver 

Creek and Corduroy Creek Basin in general found that tree 

removal had little effect on water yield, except in the case 

where runoff was increased by killing trees with herbicide 

and leaving them in place (Blackburn 1983, Baker 1986; 

Wilcox 1994). In the Beaver Creek study, juniper control by 

herbicide or cabling had no consistent effect on sediment 

yield (Blackburn 1983). Dortignac's (1960) comparison of 

the Beaver Creek data with that from experimental watersheds in New Mexico also concluded that little usable water 

yield could be expected from pinyon andjuniper manipulations. He was rightly concerned that treatments to improve 

water yield by increasing overland flow would also accelerate erosion. Increasing water yield by increasing more 

controlled and reliable subsurface flows to established 

drainages would be much more desirable for land managers. Skau (1964) noted in initial studies of Beaver Creek 

that pits left from cablingjuniper trees would trap overland 

flow. 

Hill-slope scale studies summarized by Wilcox (1994) 

suggest that cover conditions after tree control affect runoff 

and erosion. Runoff was increased by tree control when 

slash and debris were removed or windrowed, but was 

lower when trees were left on site (Gifford 1973; Wood and 

Javed 1994). Gifford (1973) concluded that debris left in 

place after chaining acted as retention and detention 

storage and minimized runoff. In that study, areas disturbed by chaining and windrowing produced 1.6 to 6 

times more sediment than untreated areas while chained 

areas with the debris left in place produced similar 

sediment as untreated areas. After burning juniper on 

steeper slopes in central Texas, runoff and sediment loss 

increased until major regrowth occurred and soil cover 

increased (Wright and others 1976). Intercanopy-scale 

USDA Forest Service Proceedings RMRS-P-9. 1999 
plots on chained, debris -in-place, revegetated areas had 5 

times less runoff and 8 times less sediment than those on 

nearby bare interspaces of a closed pinyon and juniper 

community on Green River shale sandy clay loam and clay 

loam soils in Utah (Farmer 1995). 

Wilcox (1994) reported a hill-slope scale study of runoff 

and erosion from upper elevational pinyon and juniper in 

New Mexico. Soils were shallow from volcanic tuff with 

loamy or sandy clay loam surface textures and a clay to clay 

loam argillic horizon at 10 cm. Runoff accounted for up to 18 

percent on plots with intact vegetation and up to 28 percent 

of precipitation on plots that had all vegetation removed 4 

years previously. Runoff from the plots as a percentage of 

precipitation for the 2 summers and winters measured was 

higher than that reported in the literature, but was highly 

variable yearly. Large runoff events were much less frequent than small events, and occurred with summer thunderstorms. Some runoff was produced from most storms 

during the period of highest thunderstorm activity, probably because soil infiltration capacity was decreasing as 

soil moisture from previous storms was increasing. Plot 

runoff from winter snowmelt was not observed in drainage 

channels downslope, suggesting that it was redistributed 

among source and sink areas. Most of the erosion was from 

initial heavy summer thunderstorms when soils were loose 

from spring thawing. Runoff and erosion were highest from 

plots with vegetation previously cleared. 

Subsequent studies of Wilcox and others (1996a,b) at the 

hillslope and catchment scale compared runoff and erosion 

from both stable and rapidly-eroding pinyon-juniper communities in New Mexico. Runoff was mainly produced by 

summer thunderstorms, but also occurred with snowmelt. 

The rapidly-eroding site produced more runoff and substantially more erosion than the stable site. This led Davenport and others (1998) to conclude that the rapidlyeroding site had crossed a threshold where intercanopy 

cover had been reduced enough to allow runoff through 

connected interspaces. In such a case where intercanopy 

infiltration and storage capacity are exceeded, greatly increased erosion can occur as runoff coalesces into increasingly larger channels from intercanopy to hillslope to watershed scales. Davenport and others (1998) observed that 

under conditions of high soil erosion potential, a small loss 

in interspace cover can result in a major increase in erosion. 

Rainfall simulation studies have been conducted on small 

plots to compare infiltration and sediment production of 

untreated areas with areas that have been burned (Roundy 

and others 1978), chained (Blackburn and Skau 1974), or 

cabled (Williams and others 1969; Gifford and others 1970; 

Williams and others 1972). Although infiltration rates 

decreased and sediment production increased on tree and 

shrub mounds after burning, interspace areas with lower 

infiltration rates were less affected (Roundy and others 

1978). Infiltration rates on these coarse-loamy and loamyskeletal soils in Nevada were still high enough after burning to suggest that runoff and erosion would be minimal. 

Two sites chained and seeded to crested wheatgrass (Agropyron desertorum) in Nevada had similar infiltration rates 

and sediment production as untreated areas (Blackburn 

and Skau 1974). In extensive studies on numerous cabled 

and untreated areas of Utah, Williams and others (1969) 

and Gifford and others (1970) generally found no 

USDA Forest Service Proceedings RMRS-P-9. 1999 

differences in infiltration rates and sediment loss between 

treated and untreated areas. Both infiltration rates and 

sediment loss were higher or lower for treated than untreated areas of certain sites. This variability led Williams 

and others (1972) to use site variables to try to statistically 

predict infiltration and soil loss. They concluded that responses were site specific and that no consistent relationships were found across all sites that would allow them to 

make accurate predictions among different sites. More 

process-oriented research using simulated rainfall methods is currently being conducted to improve infiltration and 

erosion prediction (Wilcox 1994; Blackburn and others 

1994; Spaeth and others 1996). 

A few studies have been conducted to evaluate soil loss 

over time in pinyon and juniper communities. Based on 

tree-root exposure dates, Carrara and Carroll (1979) concluded that soil loss from a northwestern Colorado site was 

400 percent more in the last century than in the previous 3 

centuries. Price and others (1995) estimated soil loss between pinyon and juniper trees. Assuming the soil line at 

the base of the trees was an accurate measurement for soil 

height at the time of tree invasion, they concluded that soil 

erosion had accelerated after invasion. Differences in soil 

height under and in between trees are a function of aggradation and degradation processes (West in press; Davenport and 1998) so that it is difficult to strictly attribute them 

to one or the other. Lack of differences in soil morphology 

between canopy and intercanopy patches on a site at Los 

Alamos, New Mexico (Davenport and others 1996) suggest 

that the trees do not directly increase the erodibility of a 

si te by physical effects of roots on the soil itself. 

Management Perspectives on Hydrologic 

Response to Tree Control 

Land owners, natural resource managers, and scientists 

have observed hydrologic responses of pinyon and juniper 

woodlands. Although there may be some bias about cause 

and effect in these observations, they are worthy of note 

because they give a much wider perspective oflarge-scale 

responses than has been measured or reported in the 

literature. Eddleman and Miller (1992) noted that land 

managers in central Oregon have reported loss of spring 

flow when western juniper (Juniperus occidentalis) dominates the landscape, as well as recovery of flow on some 

drainages where trees were controlled. Bedell (1987) reported a specific example of this where spring and stream 

flow increased and erosion decreased after pushing western juniper on the Bonneville Ranch in central Oregon. 

After a career ofrevegetating and observing pinyon and 

juniper lands in Utah, Stevens (in press) made a strong case 

for the beneficial hydrologic effects of chaining and seeding. 

He reported two notable cases at Ephraim and Manti, Utah 

which almost yearly received floods and debris flows from 

upslope pinyon and juniper areas until they were chained 

and seeded. He observed that summer thunderstorm runoff 

was generated from bare inters paces of unchained woodlands while chained and seeded areas nearby prod uced no 

runoff from the same storms. He also observed downslope 

treated areas to catch and hold runoff and debris from 

unchained areas upslope. He suggested that infiltration 

capacity across the landscape, rather than infiltration 

179 
rates were most important in understanding these hydrologic responses. Chaining operations that drop trees and 

leave them in place greatly increase protective soil cover 

and create detention and retention pits and depressions 

immediately after treatment. Thus when soils are just 

disturbed after chaining and most vulnerable to erosion, 

cover and detention storage is increased so that off-site 

runoff and erosion are controlled. Subsequent revegetation 

response from appropriate seeding techniques produce increased vegetation cover to control erosion as downed trees 

decompose and depression areas fill up over the years. 

Stevens' (in press) observation about chained areas catching runoff and sediment from unchained areas suggests 

that strip and pattern chainings, favored for wildlife habitat, could be sink areas at the hill-slope scale. Effectiveness 

of planted strips for controlling erosion from pinyon and 

juniper lands has been demonstrated by Heede (1990). 

Land Management Questionnaire 

To get a better understanding of the perspectives ofland 

managers relative to hydrologic responses of pinyon and 

juniper lands, we mailed a brief questionnaire to Bureau of 

Land Management, Forest Service, and Natural Resource 

Conservation Service personnel in Arizona, Colorado, New 

Mexico, Nevada, and Utah. Time constraints prevented a 

comprehensive survey of all personnel associated with 

pinyon and juniper management in these States. Basically 

we took the mailing list for this conference and sent questionnaires to anyone we thought might have pinyon and 

juniper stewardship. 

The majority of the 33 respondents which reported on 83 

sites, were from Colorado and Utah and were BLM and 

Forest Service personnel (table 2). Most of the sites reported were chained and aerial seeded, predominately with 

exotic grasses. Initial treatments were conducted at least 

20 years ago for 53 percent of the sites. Overall, treatments 

were perceived as reducing on-site erosion on more sites 

than in reducing off-site erosion, or as increasing water 

yield (table 3). Overall hydrologic success of treatments 

was considered to be good on 67 percent of the sites, with 

more Forest Service than BLM sites considered good. Comments ofland managers indicated that vegetation cover is 

the main measure used to informally assess hydrologic 

success. Erosion control and hydrologic success was perceived to have increased more on sites with clayey soils, 

than on sites with soils of loamy or coarser textures. 

Erosion was considered to be decreased and water yield 

increased by treatments on more Basin and Range and 

transition sites than on Colorado Plateau sites. The same 

trend for these variables was perceived at higher than 

lower precipitation sites. 

Table 2-Characteristics of sites represented by respondents to a questionnaire concerning watershed 

conditions and treatments of pinyon-juniper communities. Unless noted otherwise, values are 

percent of sites reported. 

Respondents (no.) 33 Soil Texture 

Total sites (no.) 83 Not reported 30 

Respondent affliation Loamy or coarser 58 

Bureau of Land Management (BLM) 39 Clayey 12 

US Forest Service (USFS) 29 Tree control 

State Wildlife Department 5 Not reported 5 

Natural Resource Conservation Service (NRCS) 11 Chained 60 

Other 17 Chained, burned 13 

State Burned 13 

Arizona 14 Other 9 

Colorado 30 Debris 

New Mexico 16 Not reported 70 

Nevada 7 Left in place 25 

Utah 31 Windrowed 5 

Other Revegetation 

Physiography Not reported 6 

Colorado Plateau 34 None 12 

Basin and Range 41 Aerial broadcast 64 

Transition 13 Drilled 8 

Other 12 Dribbler 4 

Slope Combination 6 

Not reported 18 Revegetation species 

5% 28 Not reported 20 

10% 22 Exotic grasses 42 

15-20% 22 Shrubs, forbs also reported 17 

25-45% 10 Native and exotic grasses 8 

Thunderstorm frequency None 12 

Not reported Years since treatment 

Frequent 17 Not reported 6 

Occassional 80 5 15 

Rare 10-15 8 

20-25 20 

> 30 33 

180 USDA Forest Service Proceedings RMRS-P-9. 1999 
A little less than half of the sites received no comment or 

indication on questions asking about erosion and water 

yield (table 3). This suggests that respondents either were 

not familiar with the sites for sufficient time to make an 

assessment, or that changes in these variables were not 

obvious. The perceived watershed condition of a site after 

treatment is affected by the amount of tree regrowth or 

reinvasion. Follow-up tree control was either conducted or 

considered necessary on about half of the BLM and Forest 

Service sites. A need to increase the area of original treatment was mentioned for only a few sites. The need to control 

animals better was mainly considered necessary in transition areas between the Basin and Range and Colorado 

Plateau physiographic provinces and on steeper slopes. 

Slope was generally not correlated with treatment response, except that hydrologic success after treatment of 

sites with the highest slopes (> 20 percent) was more 

frequent than for sites with lesser slopes. In general, 

responses to the questionnaire support the observations 

that pinyon-juniper watershed responses to tree control 

vary with certain site variables, and that on-site erosion 

control is a more typical response than off-site erosion 

control or increased water yield. The majority of the sites 

were considered to have improved hydrologic function after 

treatment. 

Conflicting Opinions Over Hydrologic 

Responses 

There appears to be a major disagreement in the views of 

some natural resource scientists and managers relative to 

pinyon and juniper management alternatives and associated ecological and hydrologic responses (Belsky 1996). 

Ecological understanding and substantial historical evidence support both the process and occurrence of pinyon 

andjuniper expansion and dominance with the reduced fire 

frequency that accompanied western settlement (West in 

press). What seems to be most in question is what the 

environmental consequences of that expansion really are, 

and if tree control practices will really bring proposed 

benefits. 

Tree control projects have usually been conducted by 

land managers to increase forage for domestic livestock, to 

improve watershed conditions, to increase water yield, and 

to improve wildlife habitat (Hurst 1976). The most critical 

of these purposes is the improvement of watershed 

conditions. Major tree control projects were conducted from 

the 1940's through the 1960's, but dropped offin the 1970's 

as multiple-use benefits of expensive mechanical treatments were questioned (Belsky 1996; West 1984a). 

The traditional view is that pinyon and juniper communities, especially on invasion sites, will degrade hydrologically and ecologically unless periodic fire or other tree 

Table 3-Watershed and management responses to tree control and revegetation of pinyonjuniper sites. Values are percent of sites reported from questionnaire respondents. 

A. Decreased runoff Rills, gUllies decreased 

and erosion Not reported None or sediment trapped 

All sites 43 11 46 

BLM 75 9 16 

USFS 30 9 60 

Others 15 15 69 

Colorado Plateau 75 4 22 

Basin and Range 31 16 53 

Transition 6 11 83 

Loamy or coarser soil texture 49 4 47 

Clayey 22 11 66 

Annual precipitation (mm) 

230-340 49 14 38 

350-400 52 8 40 

430-812 7 13 81 

Slope (percent) 

2-5 50 9 41 

6-10 44 0 56 

11-20 33 17 50 

21-45 22 33 44 

USDA Forest Service Proceedings RMRS-P-9. 1999 181 
B. Decreased off-site Less erosion, flooding 

erosion Not reported None or gullying 

All sites 46 29 18 

BLM 81 16 3 

USFS 13 67 20 

Others 33 11 56 

Colorado Plateau 75 18 7 

Basin and Range 32 26 42 

Transition 5 10 86 

Loamy or coarser soil texture 50 29 20 

Clayey 0 40 60 

Annual precipitation (mm) 

230-340 49 21 23 

355-400 48 36 16 

430-812 29 29 42 

Slope (percent) 

2-5 35 43 22 

6-10 50 17 34 

11-20 44 39 17 

21-45 44 11 44 

C. Increased water I ncreased stream or 

yield Not reported None spring flow 

All sites 48 26 27 

BLM 63 25 12 

USFS 46 38 16 

Others 31 15 54 

Colorado Plateau 71 29 0 

Basin and Range 32 18 50 

Transition 7 13 60 

Loamy or coarser soil texture 46 27 28 

Clayey 50 20 30 

Annual precipitation (mm) 

230-340 51 24 24 

350-400 56 28 16 

430-812 31 25 44 

Slope (percent) 

2-5 61 26 13 

6-10 50 17 34 

11-20 39 44 25 

21-45 33 33 33 

182 USDA Forest Service Proceedings RMRS-P-9. 1999 
D. General hydrologic 

success Not reported Fair Good 

All sites 12 22 67 

BLM 6 47 47 

USFS 8 12 80 

Others 22 0 77 

Colorado Plateau 4 57 39 

Basin and Range 15 6 80 

Transition 4 46 43 

Loamy or coarser soil texture 8 29 63 

Clayey 0 10 90 

Annual precipitation (mm) 

230-340 14 17 71 

350-400 10 29 62 

430-812 18 6 77 

Slope (percent) 

2-5 4 26 69 

6-10 6 34 62 

11-20 17 28 56 

21-45 0 11 89 

E. Other management Not reported Follow up Incease Control 

concerns or none Done Needed Total area animals 

All sites 36 19 26 45 4 4 

BLM 31 34 22 56 6 3 

USFS 38 13 33 46 0 4 

Others 41 7 19 26 4 8 

Colorado Plateau 18 39 32 71 4 4 

Basin and Range 44 12 21 33 3 6 

Transition 9 11 8 19 19 31 

Loamy or soil coarser texture 21 29 27 56 4 6 

Clayey 70 10 20 30 0 0 

Annual preciphation (mm) 

230-340 32 14 27 41 5 8 

350-400 32 40 16 56 4 0 

430-812 35 6 35 41 0 6 

Slope (percent) 

2-5 30 20 30 56 4 9 

6-10 39 39 17 56 0 0 

11-20 22 17 28 45 6 28 

21-45 34 0 33 33 11 22 

USDA Forest Service Proceedings RMRS-P-9. 1999 183 
reductions, and associated natural revegetation or seeding 

allow increased herbaceous and shrub cover (Doughty 1987; 

Wood 1988; West in press). Proponents of this view are 

concerned that continuing fire control and lack of other tree 

control measures are threatening the soils and associated 

resources of pinyon and juniper woodlands. West (1984b) 

suggested that most of the understory of Great Basin 

pinyon and juniper woodlands would be gone by the year 

2000. There is a concern that bare areas on many sites are 

increasing as trees established over 100 years ago are now 

maturing and as residual or newly established trees from 

earlier control projects are also maturing. Over 18 years 

ago, Hurst (1979) noted that for the 15 percent ofthe pinyon 

and juniper type that occurs on the National Forests (3.6 

million hectares in the 5 dominant States), 800,000 hectares were suitable for control treatments, and 283,000 

hectares had already been treated. More recently, the 

Forest Service has considered that 1.4 million hectares or 

35 percent of the pinyon and juniper woodland in the 

Southwestern Region are in unsatisfactory soil and watershed condition, prompting the development of active management guidelines and efforts directed at the woodlands 

(Spann 1993). 

During the period of most active control work between 

1960 and 1972 , the BLM chained 208,000 hectares, predominately in Utah (Aro 1975). Pinyon and juniper lands 

constitute approximately 17 percent or 54 million hectares 

of the 320 million hectares covered by BLM 's Vegetation 

Treatment Environmental Impact Statement (USDI 1991). 

BLM 's proposed area of vegetation treatments for all 

vegetation types and for all control methods is only 150,000 

hectares per year (USDI 1991). The BLM administers 61 

percent of the 2.2 million hectares of pinyon and juniper in 

Utah (Banner 1992). Of this, about 5 percent or 107,000 

hectares have been treated to restore herbaceous and 

shrubby vegetation. The case could be made that, if there 

are large areas dominated by pinyon andjuniper on public 

lands that are degrading, little is being done about it. West 

(1984a,b; West in press) has issued a number of calls to 

action and has helped develop guidelines for where, what, 

and how treatments should be imposed. Recent fires in the 

pinyon and juniper woodlands of Utah and Nevada have 

rekindled the concern about possible cheatgrass (Bromus 

tectorum) and other annual weed invasion into burned 

woodlands with depleted understory plants and seedbanks. 

The counter position to this concern is that maturing 

woodlands are not eroding and degrading (Belsky 1996). 

Some are concerned that land managers are using unfounded hydrologic benefits to justify tree control and 

revegetation practices that are really meant to increase 

forage for livestock. Schmidt (1987) has complained that 

selective interpretations of the literature and self-serving 

speculations have been used by some to justify type conversions. Perhaps such approaches have also been used by 

those who want to prevent tree control practices. The real 

question is to what extent, if any, are woodland sites 

eroding. References to lack of differences in infiltration 

rates or sediment production between small-scale plots on 

untreated and treated woodlands, as well as statements 

about the limited precipitation and runoff of pinyon and 

juniper woodlands have been used to conclude that erosion 

and degradation are not occurring. In fact, large, bare, 

184 

nonrocky soils of many sites are subject to intense thunderstorms that do have major erosion potential. That these and 

other potentially degrading conditions such as weed invasion are observed extensively by land managers and land 

owners (Goodloe 1993) familiar with their areas, as well as 

by scientists having a long history of extensive field work 

should bear considerable weight. 

West (1984a) has stated that there is no definitive proof 

that erosion rates have increased with tree dominance 

since it is too late to collect before and after data from the 

same site. Even if we had such data for a few sites, the site 

and soil-specific nature of hydrologic responses would prevent extrapolation to all other sites. Proponents of both 

positions agree that grazing and site-specific conditions 

have affected measured hydrologic responses. There seems 

to also be agreement that tree dominance can deplete 

understory vegetation and seedbanks. It seems rather 

obvious that understory loss has and will result in accelerated erosion on certain sites. The recent contributions of 

watershed research in New Mexico (Wilcox and others 

1996b; Breshears and others 1997b; Davenport and others 

1998) have shown the importance of spatial heterogeneity 

in pinyon-juniper woodlands, the importance of scale in 

assessing hydrologic responses, and the sensitivity of erosion to intercanopy cover, connectedness, and storage conditions. Tree invasion sites with high erosion potential 

should be identified and treated before a major erosion 

threshold is crossed. Tree control practices which leave 

downed trees and debris in place should reduce interspace 

connectedness, increase hillslope infiltration, and reduce 

runoff and erosion on sites with high SEP. 

On the other hand, land managers should not propose 

unreasonable hydrologic responses as justification for tree 

control projects. For example, on the majority of pinyon and 

juniper sites, the possibility and economic benefits of increased water yield are limited (Hibbert 1979; Brown 1987). 

Locally improved water yield is possible with suitable 

precipitation and geology, but should be considered a side 

benefit to projects which are already fully justified for 

erosion control and habitat improvement benefits. 

Most people do not oppose tree control practices that 

benefit wildlife as long as they are not damaging ecologically. Techniques that benefit wildlife such as strip-clearing, also show promise for erosion control (Heede 1990; 

Stevens in press). Mechanical methods of tree control 

should always be conducted to leave debris in place for most 

beneficial hydrologic responses on sites with high SEP. 

There are enough pinyon and juniper lands that we can be 

selective in vegetation management. We should not be so 

exclusive in land management that we totally accept or 

reject certain approaches. Rather, we should accept the fact 

that the varied conditions of our environments require a 

knowledge of specific situations and a range of management options. 

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West, N. E.; Rea, K H.; Tausch, R. J. 1975. Basic synecological 

relationships in juniper-pinyon woodlands. In: Gifford, G. H. 

and Busby, F. E. eds. The pinyon-juniper ecosystem: A symposium. 1975 May; Logan, UT. Utah State University: 41-52. 

West, N. E.; Van Pelt, N. A.; 1987. Successional patterns in pinonjuniper woodlands. In: Everett, R 1. compiler. ProceedingsPinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. 

Tech. Rep. INT 215. Ogden,UT: U. S. Department of Agriculture, Forest Service, Intermountain Research Station: 43-52. 

West, N. E.; Young, J. A. [In press.] Vegetation ofIntermountain 

valleys and lower mountain slopes. In: Barbour, M. G.; Billings, 

W. D. eds. Terrestrial vegetation of North America. Second 

edition. New York: NY: Cambridge University Press. 

Wilcox, B. P. 1994. Runoff and erosion in intercanopy zones of 

pinyon-juniper woodlands. Journal of Range Management. 47: 

285-295. 

Wilcox, B. P.; Breshears, D. D. 1995. Hydrology and ecology of 

pinon-juniper woodlands: Conceptual framework and field studies. In: Shaw, D. W.; Aldon, E. F.; LoSapio, C. technical coordinators. Desired future conditions of pinon-juniper ecosystems; 

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Collins, CO: U. S. Department of Agriculture, Forest Service, 

Rocky Mountain Forest and Range Experiment Station: 

109-119. 

Wilcox, B. P.; Breshears, D. D.1997. Interflow in semiarid environments: An overlooked process in risk assessment. Human and 

Ecological Risk Assessment. 3: 187-203. 

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Wilcox, B. P.; Newman, B. D.; Allen, C. D.; Reid, K D.; Brandes, D.; 

Pitlick, J.; Davenport, D. W. 1996a. Runoff and erosion on the 

Pajarito Plateau: Observations from the field. New Mexico 

Geological Society Guidebook, 47th Field Conference, Jemez 

Mountain Region: 433-439. 

Wilcox, B. P.; Pitlick, J.; Allen, C. D.; Davenport, D. W. 1996b. 

Runoff and erosion from a rapidly eroding pinyon-juniper 

hillslope. Advances in Hillslope Processes. 1: 61-77. 

Wilcox, B. P.; Wood, M. K 1989. Factors influencing interrill 

erosion from semiarid slopes in New Mexico. Journal of Range 

Management. 66:-70. 

Williams, G.; Gifford, G. F.; Coltharp, G. B. 1969. Infiltrometer 

studies on treated vs. untreated pinyon-juniper sites in central 

Utah. Journal of Range Management. 22: 110-114. 

Williams, G.; Gifford, G. F.; Coltharp, G. B.1972. Factors influencing infiltration and erosion on chained pinyon-juniper sites in 

Utah. Journal of Range Management. 25: 201-205. 

Wood, M. K 1988. Rangeland vegetation-hydrologic interactions. 

In: Tueller, P. T. ed. Vegetation science applications to rangeland analysis and management. Boston, MA: Kluwer Academic 

Publishers: 469-491. 

Wood, M. K; Javed, N. 1994. Hydrologic responses to fuelwood 

harvest and slash disposal in a pinyon pine and juniper dominated grassland. Trends in Hydrology. 1: 179-190. 

Wright, H. A; Bailey, A W. 1982. Fire ecology. New York, NY: 

John Wiley and Sons. 501 p. 

Wright, H. A; Churchill, F. M.; Stevens, W. C. 1976. Effect of 

prescribed burning on sediment, water yield, and water quality 

from dozed juniper lands in Texas. Journal of Range Management. 29: 294-298. 

Young, J. A.; Evans, R A; Easi, D. A 1984. Stem flow on western 

juniper (Juniperus occidentalis) trees. Weed Science. 32: 

320-327. 

187 
Watershed-Scale Research in a Juniper 

Ecosystem 

James P. Dobrowolski 

Abstract-Acquiring an understanding of the pinyon-juniper ecosystem challenges our current research technologies. Extremely 

variable site conditions and protracted time considerations result in 

a complex research environment. Utah State University has established a long-term watershed scale research site in the Clover Creek 

Management Unit near Tooele, UT. The objective is to perform 

mechanistic research in pinyon juniper ecosystem dynamics, for 

example, energy, water and nutrient cycling, organismal structure 

and function at relevant scales, sediment source/sink relationships, 

and so forth, while simultaneously addressing the more pragmatic 

concerns associated with management objectives, the effects of 

drastic disturbance and the results of custodial management. The 

project utilizes small watersheds and spatial nesting of tributary 

basins with uniform soils, slope, and aspect to provide integration 

of spatial and temporal variability and a more realistic scale for 

assessing the influence of land management activities. 

Juniper Dominated Watersheds _ 

Historically, land managers have associated canopy closure by pinyon and juniper with site degradation, measured by a reduction in desirable plant species and forage 

production for wildlife and livestock (Bedell 1987, Pieper 

1990, West 1984). A lack of management (that is, custodial 

management) is often identified with accelerated soil erosion. Other researchers have found little evidence to support the idea of environmental degradation. 

Once accepted as a sound rangeland rehabilitation program, the justification of pinyon-juniper type conversion is 

now raising concerns about disturbance of archaeological 

sites, conflicts with wilderness preservation, the recreational and economic importance of pinyon nuts, aesthetic 

values, wildlife ha.Jitat needs and the economics of brush 

management. Justification of active management by mechanical methods, chemical techniques and/or prescribed 

burning often demand answers that require a greater 

knowledge of the pinyon and juniper ecosystem than now 

exists in the available scientific literature. Soils of pinyonj uni per woodlands are typically shallow, well-drained, and 

have low fertility (see Lowe and Dobrowolski, this conference). As the trees mature, herbaceous cover declines. Due 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

James P. Dobrowolski is Associate Professor in the Department of Rangeland Resources and Acting Director, Watershed Science Unit, Utah State 

University, Logan, UT 84322-5230. 

188 

to little soil cover coupled with typically erodible soils, 

many land managers have come to the conclusion that 

pinyon and juniper invasion results in poor watershed 

condition (Bedell 1987). However, Heede (1987) found the 

microtopography produced by tree coppices (mounds that 

decrease in elevation from the trunk outward) to absorb the 

energy of flowing water and to restrict sediment delivery 

downslope. 

"Improvement" ofthe soil hydrologic condition by pinyonjuniper clearing is considered to be a fact in land management working documents and other publications (Johnsen 

and Raymond 1990). However, the concept's basis is rooted 

in an early U.S. Forest Service paper (Arnold and Schroeder 

1955) describing differences in active erosion between 

cleared and untreated areas. This conclusion was reached 

with field observations not subject to the rigors of scientific 

experimentation. 

Typically, many published studies focussed on different 

technologies to improve the forage resource and they only 

included ancillary observations of the treatment effects on 

soil hydrologic condition. Clary and others (1974) found no 

meaningful change in sediment yield after removing pinyon-juniper by cabling or the application of herbicides at 

Beaver Creek, Arizona. Measured salt concentrations produced from surface soils of pinyon-juniper sites are not 

cri tical to deli very of sal t wi thin maj or ri ver basins (Hessary 

and Gifford 1979). Gifford (1987) in Utah and Wood and 

Wood (1988) in New Mexico concluded that removal of 

pinyon-juniper by chaining does not reduce sediment 

production. 

Many erosion plot studies (sensu Buckhouse and Gifford 

1976, Busby and Gifford 1981) have relied on a limited 

number of rainfall events with the potential to produce 

overland flow. Standard erosion plots typically represent 

the spatial effects of only one tree and its associated intercanopy spaces. These plots often were installed prior to the 

collection of pretreatment data. When sample size is small, 

spatial interspersion is missing, and/or pretreatment data 

is lacking, the power of the statistical test can be substantially affected, risking the possibility of a Type II statistical 

error and the problems associated with it. An error of the 

second kind or Type II error is made when the experimenter 

accepts the null hypothesis and the alternative is true. The 

concept of a Type II error is particularly important in 

determining the sample size necessary to detect a difference of an a priori magnitude. 

Williams and Buckhouse (1993) measured the amount of 

sediment exported and overland flow differences from 10 

different ecosystems in eastern Oregon. Using runoff plots 

(1 x 5 m) treated with simulated rainfall,juniper dominated 

systems were found to have greater overland flow and 

higher potential for sediment export. However, Williams 

(personal communication) felt that efforts to distinguish 

USDA Forest Service Proceedings RMRS-P-9. 1999 
differences in sediment production from treated and undisturbed ponderosa pine ecosystems with the same runoff 

plot technology (Williams and Buckhouse 1993), was susceptible to a Type II error. 

A Self-Destructive Ecosystem? 

Researchers have postulated that successional trajectories currently in place and likely to carryon for future 

centuries due to tree longevity, result in a self-destructive 

system. Carrara and Carroll (1979) and others felt that a 

large portion of the pinyon-juniper type is exhibiting undesirable successional tree "superdominance" leading to site 

degradation due to loss of biodiversity, the threat ofa fire 

holocaust, in addition to accelerated soil loss. West and 

Van Pelt (1987) expressed a need to know where and why 

this was occurring, and felt these disturbing trends to 

contradict the prevalent idea that succession always leads 

to more stable, more diverse, and more economically valuable communities. Pinyon-juniper woodlands at higher 

elevations tend to follow the usual concept of linear plant 

succession. On sites when the time between regeneration 

events is longer than the lifespan of established trees, 

alternative steady states occur (Jameson 1987). The successional trajectory of pinyon-juniper sites subjected to 

drastic disturbance appears to depend upon the density 

and size of trees before disturbance (Schott and Pieper 

1987). Tausch (1977) found a steady reduction of understory cover and production beyond the fifth to eighth year 

after drastic disturbance, dependent upon site characteristics. 

It is imperative that land managers have the knowledge 

to anticipate what will happen with successional change 

and be able to recognize problems associated with unimpeded succession (Schott and Pieper 1986). 

Pinyon-Juniper Woodlands and 

Climatic Change: Source or Sink for 

Carbon? 

In addition to their potential influence on water cycling, 

these ecosystems might influence global temperature change 

most directly by acting either as a sink for excess CO2 or by 

giving up some of the CO2 currently stored, that is, act as a 

carbon "source" (Perry and others 1991). Net primary 

production (NPP) can increase and thereby sequester carbon or the decay of organic matter may be greater than 

NPP, or fire, insects and drought may reduce NPP leading 

to a release of CO2 , Destruction of forests and drastic 

disturbance have been linked to a 30 percent increase in 

atmospheric CO2 in this century. Little is known about the 

carbon cycling properties of a pinyon-juniper woodland. 

Efforts to investigate nutrient accumulation in pinyonjuniper woodlands were traditionally restricted to the fate 

of plant macronutrients after application of some management technology (DeBano and others 1987). With the recent interest in global climatic change and the concentration of greenhouse gases in the atmosphere, knowledge of 

the temporal dynamics of carbon cycling and feedback 

interactions in the pinyon-juniper ecosystem is essential 

USDA Forest Service Proceedings RMRS-P-9. 1999 

(Perry and others 1991). Productivity of pinyon pines and 

junipers as indexed by carbon gain was found to be highly 

correlated to some abiotic factors, particularly soil moisture (Barnes and Cunningham 1987). Klopatek (1987) 

found organic carbon contents of the soil beneath canopies 

to be statistically greater for mature pinyon-juniper canopies than stands recovering from historic fire. 

Scale Considerations 

Space 

New plot data have sparked further debate over the relationship between soil hydrologic condition and the pinyonjuniper ecosystem. These data might have limited statistical 

inference simply because of small plot size (1 x 3 m). Small 

plots, including the standard erosion plot (3 x 10 m) often 

neglect the spatial mosaic of soil hydrologic conditions typical 

of the pinyon-juniper ecosystem. Plots may only encompass 

the influence of one or possibly two pinyon or juniper trees. 

Heede (1987) determined that spatial variability imparted to 

the pinyon-juniper site by litter-produced hummocks reduced 

the slope gradients and diverted runoff. In this case Heede's 

experimental areas were 5 x 8 m "microwatersheds." Heede's 

microwatersheds, which add 10 square meters to the standard erosion plot, likely cannot escape the same criticism 

for a lack of spatial representation. 

A watershed-scale study integrates spatial and temporal 

variability and provides a more realistic scale for assessing 

the influence of land management activities. In addition, 

modelling scale-dependent problems such as a changing 

global climate requires the procurement of data at a variety 

of scales. Standard experimental watershed methodologies, such as the paired-watershed approach, often require 

two like watersheds and the calibration of flow from each 

watershed. These experimental procedures have been criticized for their high cost and for the apparent difficulty in 

extrapolation. Proper design, cautious planning and careful site selection can augment statistical inference from 

results and address the criticisms of an experimental watershed approach (Bosch and Hewlett 1982). 

Time 

The time scale for pinyon-juniper research is very difficult to realistically accommodate. Houghton (1969) states 

that it may take 30 years or more simply to determine 

average annual precipitation in the Great Basin. Pinyonjuniper, and other western woodlands tend to exhibit very 

low dynamism (Little 1987) and appear to be some of the 

most static of all western ecosystems (West and Van Pelt 

1987). These attributes exceed the life expectancy and 

attention span of most research efforts. Past research was 

conducted over a few years period, often coinciding with the 

availability of graduate student assistance. The long 

lifespans and time to maturity ofthe trees means that they 

are subject to significant environmental fluctuations and 

disturbances requiring patient observation, hence the minim urn requirement of a 10-year experimental horizon planned 

for the study proposed here. Long-term watershed studies 

189 
are needed to provide a frame of reference for shorter-term 

plot research (Schmidt 1987). 

Study Objectives ______ _ 

1. To establish a long-term, watershed-scale research 

site for applied and basic research into the dynamics of a 

Great Basin pinyon-juniper ecosystem. This effort will 

involve investigators from across the USU campus and be 

coordinated with other regional studies at Los Alamos 

National Laboratory, Oregon State University, and the 

University of Nevada, Reno. Utah Agricultural Experiment Station funds will be used to delineate the site and to 

promote the acquisition of development funding from other 

sources. It is hoped that a study at a watershed scale will 

eventually be assisted by long-term ec-ological reserve funding (LTER, partially funded by the National Science Foundation), representing a pinyon-juniper ecosystem in the 

Great Basin. 

2. To perform mechanistic research of pinyon-juniper 

ecosystem dynamics, such as, energy, water and nutrient 

cycling, organismal structure and function at relevant 

scales, sediment source/sink relationships, and so forth, 

while simultaneously addressing the more pragmatic concerns associated with management by objectives, the effects of drastic disturbance, or the results of custodial 

management. 

• Do sites that are dominated by mature, middle-aged, 

or young pinyon-juniper represent degraded or degrading 

sites? 

Sediment source / sink relationships, soil profile / organic 

carbon dating 

• Why might pinyon-juniper dominance influence 

biodiversity? How will understory plants respond to partial 

or complete removal of the pinyon-juniper overstory? How 

will the abundance of mammal and bird species change 

with shifting successional stage? 

Mechanical manipulation under best management 

practices, simulated catastrophic wildfire, mosaic 

thinning 

• How does the water balance of a pinyon-juniper ecosystem change when vegetation dominance shifts? 

Mosaic thinning, tree removal with an undisturbed 

understory 

• Does a pinyon-juniper ecosy..:;tem act as a source or 

sink for carbon? 

Ecophysiological studies of drastically disturbed and / or 

relatively undisturbed stands at different age classes 

• Why are pinyon and juniper trees considered to be 

invasive under some conditions? What are the dispersal 

mechanisms in the Great Basin? 

Pinyon-juniper population dynamics in drastically 

disturbed and / or relatively undisturbed environments 

190 

Pinyon-juniper research by Utah State University will 

attempt to define and resolve these critical ecological questions at the watershed scale. 

Study Design _______ _ 

We propose to use an overall study design that was 

successfully applied to answer geomorphic and ecologic 

questions in Australia, Great Britain, and the U.S., 

a nested-watershed approach (sensu Jarvis 1976, Neary 

1985). Spatial nesting of tributary basins with uniform 

soils, slope, and aspect is identified, and these tributary 

basins are instrumented as components of a larger watershed (fig. 1). Often the watershed measuring devices are 

located so that each drainage area monitored increases by 

an order of magnitude from one location to the next 

(Amphlett and others 1987). Nested subareas (1.2 to 

98.9 km2) of the Highland Water Catchment in Great 

Britain were used to analyze the difference in runoff depth 

and peak discharge between heath and woodland covered 

areas at several spatial scales (Gurnell and others 1990). 

Six nested watersheds provided the background for a study 

of the spatial and temporal variation in suspended sediment from different cropping systems in central Iowa 

(Hamlett and others 1987). At the variable scales common 

. ........ -......... --- --~'-- ............. 

I ..... , .. ,.,., 

Figure 1-Nested tributaries within a larger watershed (redrawn from Jarvis 1976). Potential treatments are indicted for illustrative purposes. 

CONTROL "' \ 

\ 

to a nested watershed study, Dickinson and others (1990) 

were able to show dramatic variations between annual 

sediment yields, and suggested that the common procedure 

of applying sediment ratings to fill data gaps on noninstrumented watersheds is not recommended. 

In our study, different land treatments will be applied to 

these small "nested" watersheds and the integrated effects 

assessed by the larger watershed (fig. 1). These studies of 

small watershed process, nested within a larger watershed 

require intensive efforts but can often make use of very 

simple techniques over short periods. A summary and 

review of 94 catchment experiments throughout the world 

revealed that paired, nested, or grouped catchment experiUSDA Forest Service Proceedings RMRS-P-9. 1999 
ments produced stronger evidence than less controlled 

studies (Bosch and Hewlett 1982). The nested approach 

will provide an opportunity to confirm or extrapolate smallscale findings (Nowson 1979). 

Theoretical Basis for Nested 

Watersheds 

The attributes that set this proposed research apart from 

earlier efforts to establish cause and effect include: 

1. Physically and biologically meaningful spatial scales 

that are integrated. 

2. A philosophy based upon the assumption that an 

understanding of processes (process-oriented research) provides greater power to predict system response to perturbation. Additionally, using a mechanistic approach, looking 

for mechanisms that can be explained in terms of physics 

and chemistry. 

3. A reasonably long time scale to obtain relevant results. 

4. A study design that is flexible enough to provide for 

statistical analyses and the application of deterministic 

modelling (Deschesnes and others 1985). 

Study Area ________ _ 

The Clover Creek Watershed is located in northeastern 

Tooele County approximately 32 km (20 miles) south of 

Tooele, Utah (St. John Quad, Sect. 35, T.6S, R.6E). The 

study area straddles the semidesert and upland climatic 

zones. Precipitation averages 32 cm (12.8 inches) each year 

with approximately 88 percent coming as snow and 12 

percent as spring and summer thunderstorms. Temperatures can range from -7°C to 38 °C (-19 to 101°F) 

throughout the year. Soils were formed from alluvial deposits and they are presently classified as loamy-carbonatic, 

mesic, aridic Petrocalcic Palexerolls of the Borvant series. 

The vegetation type is ajunipe-rwoodland thatinterdigitates 

with a shrub steppe. The overs tory is dominated by Utah 

juniper (Juniperus osteosperma) with an understory composed of microbiotic crusts and Indian ricegrass (Oryzopsis 

hymenoides), Sandberg's bluegrass (Poa secunda), 

bluebunch wheatgrass (Pseudorigneria spicata), and a mix 

of introduced grasses and forbs. Tree interspace dominants 

include Wyoming big sagebrush (Artemisia tridentata ssp. 

wyomingensis) and gray rabbitbrush (Chrysothamnus 

nauseosus), understory composition is similar to the juniper understory. 

Potential Treatments ------------------- Mosaic Thinning 

As canopies close, herb species appear to dwindle to a 

fairly stable set exhibiting shade tolerance. In long-lived 

tree stands with shade-tolerant herbs, some researchers 

feel that partial removal of the canopy can negatively 

influence the herb biomass (Papp 1977) and their relative 

importance (Metzger and Shultz 1984). However, Reader 

USDA Forest Service Proceedings RMRS-P-9. 1999 

and Bricker (1992) found partial canopy removal in a 

deciduous forest, to conserve the understory herbs. Herb 

species disappeared from undisturbed forest at about the 

same rate as partial canopy removal. These results suggest 

a "conserving function" that could be used to help preserve 

the forest understory. Manipulating the small watersheds 

at Clover Creek using a mosaic approach offers a unique 

opportunity to elucidate some of the processes producing 

these conflicting results. It will also add to a depauperate 

literature for selective removal of unmerchantable timber. 

Simulated Wildfire 

Canopy closure in the pinyon-juniper ecosystem appears 

to reduce the fine fuels available for surface fires, with the 

result that eventually, prescribed burning becomes an 

ineffective vegetation manipulation tool (Blackburn 1983). 

At the same time, the threat oflarge-scale destruction by a 

crown fire increases. Evaluation of the consequences of a 

severe wildfire through tree crowns is important to the 

understanding of ecosystem dynamics and risk analysis 

under custodial management (Tausch and West 1989). 

Application of a full-scale wildfire treatment with the 

in tensi ty necessary to reproduce the effects of a firestorm is 

not possible for obvious safety reasons. However, a portable 

propane plant burner, originally developed for use in evaluatingthe effects offire on individual plants, can be adapted 

to apply specific time-temperature heat treatments to the 

pinyon-juniper understory. Propane burners can be constructed in a variety of sizes, depending upon the species to 

be treated. According to Dr. Allen Rasmussen (personal 

communication), a burner unit capable of moving over the 

soil surface could be designed and used to simulate wildfire 

at a small watershed scale without the threats posed by 

na tural fire. 

Mechanical Manipulation 

When pinyon-juniper is uninhibited either by fire or by 

full-scale plant competition, the trees, with their resistance 

to herbivory and decay and greater physiological efficiency, 

permits thickening of their cover. That correlates, in most 

previous studies, with a further decline in understory 

productivity as they mature (West 1984). Dragging an 

anchor chain between two bulldozers or "chaining" has 

been used throughout the U.S. since the 1950's to remove 

unwanted woody vegetation. Typically, chaining was carried out in the most level portion of a pinyon-juniper 

dominated watershed. This heavy treatment produced an 

expected canopy cover shift from trees to seeded grasses, 

potentially lasting for at least 56 years. Disturbance levels 

and recovery times depend upon a myriad offactors. Disturbance levels are altered by the number of passes of the 

chain (for example, one-way versus two-way chaining), 

whether angle iron is welded to the chain, application 

season, and composition of the seeded mix. The permutations are numerous. Best management practices (BMP's) 

exist, taking slightly different forms for each management 

agency. These experimental studies are not intended to 

evaluate the efficacy of BMP's per se, though knowledge 

191 
about the effects of this type of disturbance on pinyonjuniper at Clover Creek under the established environmental and experimental conditions will be greatly enhanced. 

Untreated Control (Pre-existing and 

Existing Ecosystem Dynamics) 

Carbon Sequestration-A recent workshop about the 

natural sinks of carbon dioxide (Wisniewski and Lugo 

1992) proposed the hypothesis that temperate and tropical 

forests have the potential to sequester a part of the 

carbon emitted by the burning of fossil fuels not found in 

atmospheric and oceanic cycling. Terrestrial ecosystems 

supporting pinyon-juniper woodlands may be absorbing 

some of this misplaced carbon. As pinyon-juniper forests 

expand, increases in carbon storage may occur under similar circumstances as the increase in European forests since 

the industrial revolution. Glenn and others (1993) indicated that reversing the trend towards desertification by 

restoration and revegetation of degraded rangelands could, 

in part, result in net carbon sequestration. Annual biomass 

yields will need to be assessed that can produce values for 

net carbon uptake (sensu Sedjo 1989). Investigation of 

carbon residence times in soils supporting pinyon and 

juniper, likely significantly greater than forest soils, will 

require effort and coordination by cooperating scientists 

(Rick Miller, USDA-ARS, Burns, OR; David Breshears, and 

others, USDOE, Los Alamos). 

Seed Dispersal and Population Dynamics-Koniak 

and Everett (1982) assert that when closed canopies of 

pinyon-juniper are opened artificially, few native plants 

tend to recover, apparently because seed banks and seed 

sources have been lost. The proposed experimental manipulations may be too small to gain a reasonable understanding of how large-scale treatments affect patterns of 

seedfall and seed predation due to the proximity and influence of the surrounding matrix. However, since treatment 

manipulations may differentially affect shading, water 

availability, and competition, experimental studies can be 

designed to elicit how these factors influence the incorporation of seeds into the soil, germination and successful 

emergence, establishment, growth and survival of seedlings (Eugene Schupp 1997, personal communication). 

HistoricallEcological Relationships-See Creque, 

West, and Dobrowolski this proceedings. 

Social Considerations-The relatively recent and vocal concern over land improvement practices in pinyonjuniper woodlands fosters a need to understand public 

attitudes toward such practices as chaining, prescribed 

burning, and seeding. The Clover Creek Study Area offers 

an opportunity for social science research that might link 

general attitudes toward rangeland improvement practices with photographs of actual sites over a period of years. 

Lay persons can be asked to evaluate trade-offs among 

alternative management scenarios after viewing computersimulated photographs and hearing site-specific information about biodiversity, soil erosion, and other biophysical 

factors. 

192 

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U.S. For. Servo Gen. Tech. Rep. RM-149: 195-198. 

Hessary, I.K. and G.F. Gifford. 1979. Probable impacts of various 

range improvement practices on diffuse salt. J. Range Manage. 

32: 189-193. 

Houghton, J.C. 1969. Characteristics of rainfall in the Great Basin. 

Desert Res. Inst., Univ. Nevada, Reno. 205 p. 

Jameson, D.A. 1987. Climax or alternative steady states in woodland ecology. U.S. For. Servo Gen. Tech. Rep. INT-215: 9-13. 

Jarvis, M.J. 1976. Classification of nested tributary basins in 

analysis of drainage basin shape. Water Resour. Res. 12: 

1151-1164. 

Johnsen, T.N. and S.D. Raymond. 1990. Managing individualjuniper and pinyon infestations with pelleted tebuthiuron or picloram. J. Range Manage. 43: 249-252. 

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Tech. Rep. INT-215: 391-396. 

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USDA Forest Service Proceedings RMRS-P-9. 1999 
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47 years. U.S. Forest Servo Gen. Tech. Rep. INT-215: 65-68. 

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193 
Hydrogeology and Spring Occurrence of a 

Disturbed Juniper Woodland in Rush Valley, 

Utah 

Francis J. McCarthy III 

James P. Dobrowolski 

Abstract-Recent concerns over the quality of water delivered to 

domestic wells in Rush Valley have prompted an interest in 

water yields from tributary watersheds. Removal of juniper trees 

(Juniperus osteosperma) by wildfire and prescribed burning has 

altered the hydrologic regime of these small watersheds. The saturated areas and perennial springs that have emerged might offer 

direct benefits to humans, livestock and wildlife in the form of 

greater vegetation production later in the growing season and as 

more reliable wa ter sources. We are collecting baseline hydrogeologic 

data and investigating the emergence of springs. Specific objectives 

include the determination Qf subsurface flow paths to selected 

springs and computer modeling to predict potential spring occurrence. The study area near Tooele, UT, is geologically and hydrologically complex. Most of the springs appear to occur at points of 

subsurface flow concentration where a shallow soil mantle exists 

over shale, or where fractured and solution cavities in rock are 

exposed and these cavities are simultaneously underlain by impermeable shale. 

The removal of juniper trees (Juniperus osteosperma) has 

altered the hydrologic regime of several small watersheds in 

the Johnson Pass area of Rush Valley, Utah. Large increases 

in spring activity and water yields were observed after 

wildfires and prescribed burns removed junipers from tributary watersheds. Recent concern over watershed condition 

and the quality of water delivered to domestic wells in Rush 

Valley has prompted an interest in water yielded from 

upslope areas. Efforts to improve the watershed condition 

for wildlife and livestock, as well as the quantity and quality 

of the ground water within the valley, have led to the 

formation of the Clover Creek Coordinated Resource Management Plan (CRMP) (USDA 1997). The purpose of the 

CRMP is to increase and maintain the availability and 

duration of surface water flows, enhance ground water 

recharge, increase and maintain plant diversity and structure, and provide quality habitat for wildlife and livestock. 

The objectives will be met using a variety of management 

practices, primarily vegetation manipulation. The study 

area near Johnson Pass has been established by the Utah 

State University Department of Rangeland Resources and 

the Utah Agricultural Experimental Station. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Francis J. McCarthy III is Research Assistant and James P. Dobrowolski is 

Associate Professor, Department of Rangeland Resources and Acting Director, 

Watershed Science Unit, Utah State University, Logan, UT 84322-5230. 

194 

Over the past 100 years, fire suppression and overgrazing 

likely led to increased tree density and/or invasion of 

juniper trees into adjacent rangeland throughout the region (West 1989, USDA 1997). Oblique photographs from 

the 1880's show an area with much lower juniper tree 

density and aerial extent than in 1997 (fig. 1). Portions of 

the study area were chained and seeded with grasses in 

1974 and 1975 to remove the juniper and increase forage 

availability. In 1991, wildfires and prescribed burning 

removed additional junipers, especially on the upper portions of the watershed. Following the fires, numerous seeps, 

wet meadows and perennial springs emerged. Riparian 

areas are developing within previously dry stream 

channels. 

The purpose of this investigation is to provide baseline 

hydrogeological data for our study area and examine the 

emergence of springs. Specific objectives include the 

determination of subsurface flow paths to selected springs 

and computer modeling to predict potential spring occurrence. The Johnson Pass area is geologically and hydrologically complex (fig. 2). Several mechanisms for spring 

Figure 1-Top photograph was taken in the 1880's of the 

southern end of the Stansbury Mountains looking north into 

the Big Hollow area. Note small number of junipers on 

lower hillslopes when compared to the bottom photograph 

taken in November 1996 of the southern end of the 

Stansburys and northern Onaqui Mountains looking northwest into the Big Hollow and Johnson Pass areas. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Figure 2-Geologic map with the study area outlined by a black rectangle (after Croft 1956). 

USDA Forest Service Proceedings RMRS-P-9. 1999 

EXPLANATION 

SEDIMENTARY ROCKS 

>-

a:: 

4 

z 

a:: 

w 

I4 

~ 

o 

Sand 

-dun •• 

o 

Alluv j"ra 

H::::thF?1 Lak, Bonn.", III, troup 

If?fit~~J 

~:f;Q"i:j z Oq\tlrrh ormotion 

~ t,~~~;,r" i:~'~;;;"f" ~ Oquirrh ,,,,. Oquirrh tor.otio. 

>- AI~ .. 

~ 

~ Oquirrh ~ form.l,o. 

~ I" 

•••••• 

• ;;.. "1~;':.r:J' MTe°f~" "0' / ' 

y-! ~!I,!~'_~~~~ 

Z Great ~ Blu. Ilme5tan. 

~ 1'.1 sholl ~ 

~ 

(ii 

f.Q Humb"'Q formation 

~ f;i\~p~:t~1 

~[ 

~[ 

Gordn.r dolomlt. 

a D''Ionian unci/ rf 

o Lakefown dolamtf. 

Fi&I\Oy In dol Q mit. 

Swan 

~ 

~ P.ak qtlltt. 

SYMBOLS ~30 

Olp and Strike 

+30 

Strike and Dip af ov.rturnldb_d. 

Fautt- Ihawlng probable 

location wh.redalhld 

Foult-thowlnt r.latlv ... ovlment 

. 

M 

Thrult 

~ 

FQult- t •• th 

on overthrust block 

Hac:hur. on a contact art 

on thl lid. of th' younger 

oDd ov.rlapPlng dlpo&ita 

AntiCline-showing tract 

of GJ.i.a1 plane 

S),ncll".- Iho"ing IrDce 

of axial pion. 

~ YIOOOO 

Follil coiliction lacQUr, 

FQftal of f 11ft". I Dr adi' 

5pring 

ROG d • 

195 
limestor.le 

Faults 

Figure 3-(A) Subsurface flow over a soil mantle resulting 

in a spring where the soil pinches out. (8) Possible flow 

paths through confined layers or along faults overlain on 

part of cross section (after Croft 1956). 

emergence are possible. It is hypothesized that most of the 

springs occur at points of subsurface flow concentration 

where a shallow soil mantle exists over low permeability 

bedrock, such as shale, or other barrier to flow (fig. 3A) 

(Watson and Burnett 1995). Alternatively, water may flow 

through a confined aquifer of fractured bedrock or bedrock 

with solution cavities. The flow might be controlled by 

structural features such as faults which provide preferential 

flow zones or fracture the area into discrete packets of 

infiltration transfer and discharge across the site (fig. 3B). 

Study Area ________ _ 

The study area is located in a high valley in the transition 

zone between the northern Onaqui Mountains and the 

southern Stansbury Mountains. Elevations within the study 

area range from 1,524 to 2,408 m (5,000 to 7,900 ft) above sea 

level. Relief is moderate compared to the surrounding terrain. Temperatures range from below zero in the winter to 

over 40°C (-20 to 100+ OF) in the summer. Precipitation 

averages 480 mm (19 inches) per year (USDA 1988). 

Approximately 88 percent occurs as snowfall during the 

winter. Occasional monsoonal thunderstorms drop large 

amounts of precipitation on the area in short periods oftime. 

Vegetation in the area consists primarily of grasses and 

shrubs where the junipers have been removed. Soils are 

thin, generally less than 50 cm (20 inches), and poorly 

developed (USDA 1988). Few geologic studies have been 

conducted in the area. Previous mapping efforts focused on 

larger scale structures and formations (Croft 1956). Three 

geologic formations are present, the Mississippian Great 

Blue Limestone, the Mississippian and Pennsylvanian Manning Canyon Shale and the Pennsylvanian to Permian 

Oquirrh Formation. The Great Blue Limestone consists of 

massive, thick bedded, medium to dark gray limestone. It is 

resistant to erosion and forms the western ridge of the study 

196 

area. The majority of the study area is underlain by the 

Manning Canyon Shale. This is composed of three units: a 

lower black shale, a medial dark gray limestone unit and an 

upper black shale and quartzite unit (Rigby 1958). The 

shales are thin bedded and highly fissile. The shales are 

easily erodible and frequently buried. The medial quartzite 

outcrops very strongly across the study area and may be 

mapped as a marker bed. Quartzite layers are very hard and 

often have a scintillating appearance and visible cross bedding (Rigby 1958). The Oquirrh Formation outcrops strongly 

across the eastern side of the study area. It is primarily 

composed of hard, black to gray, well-bedded limestone with 

occasional clastic layers. Several strong structural features 

are evident across the area. The area is broadly warped into 

an anticline and syncline (fig. 3B) as part of a regional fold 

and thrust system. Numerous minor faults and folds occur 

within the area. Several periods of faulting have occurred. 

Ancient thrust faults were later dissected by strike-slip 

faulting and finally by Basin and Range normal faulting 

(Croft 1956). Muchofthethrustfaultingoccurred within the 

Manning Canyon Shale making the stratigraphy hard to 

map due to omission or repetition oflithologic units (Rigby 

1958). 

The hydrology ofthe area focuses on two perennial spring 

fed streams, Chokecherry Creek and Serviceberry Creek. 

Annual mean flows are estimated to be less than 0.14 m3/sec 

(5 ft3/sec (cfs)) and the streams have historically dried up 

during the summer months (Darrell Johnson, personal communication 1997). Recent increases in water yields have 

resulted in the streams flowing all year with the creation 

and extension of riparian areas. Several wet meadows have 

appeared where springs occur outside of stream channels. 

Methods _________ _ 

The investigation consists of a two-phased approach. The 

first phase consists of detailed Global Positioning System 

(GPS) assisted hydrologic and geologic mapping, including 

the construction of several piezometers to monitor potentiometric surface and map depth to bedrock. The second phase 

involves predicting the occurrence of springs and the potential for spring occurrence using a geographic information 

system and flow path analysis. 

Phase I efforts consisted of detailed mapping of streams, 

roads, springs, geological contacts, geological data points, 

water troughs, and numerous other points of interest utilizing a handheld GPS to produce high resolution, high accuracy maps. These data are then spatially corrected and 

incorporated into a GIS. Earlier mapping data also will be 

incorporated into the GIS. 

We are constructing stratigraphic and structural geologic maps to identify water bearing units and their orientation and lateral extent. Stratigraphic mapping consists of 

identifying and characterizing individual lithologic units 

and their vertical sequence. Geologic and structural mapping helps to determine the lateral extent and three dimensional orientation of each lithologic unit. Of special interest 

is the identification of folds and faults that might act as 

preferential flow paths. Field mapping will be supplemented 

by high resolution aerial photography. One to five thousand 

scale color infrared stereoscopic photographs will be acquired and used to assist surface mapping and the creation 

of high resolution digital terrain models (DTM's). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
From these mapping efforts, several sites will be selected 

for construction of5 cm (2 inches) piezometers to determine 

the potentiometric surface and monitor ground water levels. 

A 9.8 cm (3.87 inches) borehole will be drilled using a direct 

mud rotary technique. During drilling, information on 

soils, lithology, depth to bedrock, and depth to water will be 

collected and incorporated into the GIS. The piezometers 

will be completed with 5 cm PVC pipe with a screened 

interval ofl.5 to 3 m (5 to 10 ft). In areas with more than one 

water bearing unit nested piezometers will be screened to 

measure the potentiometric surface of each unit. 

Phase II involves GIS modeling to attempt to determine 

what parameters promote spring occurrence and to use 

these parameters to predict current spring locations where 

springs might appear and to predict spring development iff 

when the vegetation is manipulated. Preliminary efforts 

used standard 30 m x 30 m (98 x 98 ftrpixel size digital terrain 

models to examine the flow accumulation and the curvatures of the slope profile and planform to identify possible 

points of concentration in the topography where springs 

are likely to occur. Finer resolution DTM's will be created to 

determine drainage area, relief, aspect, slope length, curvature, and other topographic features related to each spring 

occurrence. These data will then be overlain with the GIS 

coverages of geology, potentiometric surface, depth to bedrock, and vegetation to identify the strongest influences on 

spring occurrence. If the model can be calibrated, it will be 

used to predict spring occurrence if the vegetation is 

manipulated. 

Preliminary Results and 

Discussion ------------------------------- At present, results show that GPS based mapping is very 

efficient and rapidly converted to GIS coverages. Most ofthe 

data collected is still of a qualitative nature, however, 

several strong features can be noted. Figure 4 shows the 

North 

,-" ._-------,,-._-_ .. _._-_._------=---.. _--_._---------- -----.~--~------.--.-. 

t 

Map of geology and spring ocurrence Southern 

Serviceberry Creek watershed. 

=-Crossection line _ Wet meadows , Spring - - - Fault 

- Streams ~.' Middle Gray Limestone of Manning Canyon Fm. 

Figure 4-Geographic Information System (GIS) based map of a portion oftheChokecherry 

Creek tributary watershed. 

USDA Forest Service Proceedings RMRS-P-9. 1999 197 
locations of springs, saturated areas, streams, watershed 

boundaries, roads, geological contacts, and outcrop locations. Only the distinct contacts between the Manning 

Canyon Shale upper and lower units and the medial limestone, and the contact between the Manning Canyon Shale 

and the Oquirrh Formation were mapped using the GPS. 

Numerous strike and dip points represented by the triangles were taken to determine the orientation of the lithology. The stratigraphy is interrupted by several faults and 

folds within the area making stratigraphic mapping difficult. However, by focusing on the shale-limestone contacts, 

it is possible to get a general picture of the structure and 

lateral extent of lithologic units. Springs mostly appear 

along the contact of the shales and limestones, especially 

where the Manning Canyon Shale contacts the Oquirrh 

Formation. 

The most apparent features mapped-are the wet meadows 

and other saturated areas. Several hectares of saturated soil 

are apparent all year. The limited infiltration of these areas 

from high antecedent moisture levels, might lead to greater 

runoff and a concomitant increase in hydrograph storm 

peaks (Betson 1964, Dunne and Black 1970). 

Slope instability and seepage erosion were observed in 

several locations across the site. Figure 5 indicates a fenced 

exclosure that was disturbed by failure of the slope. Strong 

seepage erosion appears to have undermined soil and bedrock creating spring sapping features such as streams emanating from steep semicircular slopes. Several areas across 

the site have similar features without flowing streams, 

indicating relict spring sapping features. These may provide 

additional insight to subsurface water flow in the area and 

might be incorporated into the predictive model. 

Initial stratigraphic mapping shows that the Great Blue 

Limestone contains abundant solution cavities which might 

act as an aquifer, however, few spring occurrences were 

observed in the formation. The Manning Canyon Shale is 

generally impervious, although some areas are highly fractured and have open calcite lined fractures capable of moving water (Arthur 1961). The quartzite within the Manning 

Canyon Shale often contains open fractures that also may 

act as conduits for flow. Whether the medial limestone acts 

Figure 5-Active seepage erosion occurring in one of 

the tributary watersheds. 

198 

Figure 6-Potential spring occurrence sites shown in 

grey-white based on slope curvature and flow accumulation. Actual springs are in black at 30 x 30 m (98 x 98 

ft) pixel sizes. 

N 

t 

as an aquifer or barrier to flow has yet to be fully determined. 

Many of the springs appear to emanate below this unit. 

Manning Canyon Shale medial limestone outcrop patterns suggest that numerous smaller folds exist across the 

area, as well as several unmapped faults. Detailed mapping 

should reveal continuation of previously mapped faults 

through the shale. These faults and folds might be important 

in controlling the behavior of many ofthe springs in the area. 

These structures might result in separate discrete zones of 

infiltration, transfer, and discharge with much ofthe transfer and discharge occurring along faults or areas where 

deeper soils pinch out. Movement through the soil mantle is 

likely, however, mapping suggests soils are too shallow 

and too laterally discontinuous to provide continuous flow 

paths. The geology of the site appears to inhibit deep penetration of ground water. Small changes in the water budget 

due to vegetation manipulation or climate change should be 

readily visible in the stream and springs. 

Initial efforts to model the flow accumulation and curvature of the slopes using low resolution (30 m, 98 ft) DTM's to 

identify zones of flow concentration where springs might 

occur indicated poor results (fig. 6). Most spring features are 

smaller than 30 m and are obscured by the grid. Higher 

resolution DTM's (2 m, 6 ft) should provide enough detail to 

parameterize the area. 

Conclusions ------------------------------

Preliminary results indicate that most subsurface flow is 

through fractured bedrock and that the structure might create 

discrete packets ofinfiltration, transfer and discharge across 

the site. Depth to bedrock, depth to water, and the potentiometric surface will be important to determining the flow 

paths to springs. The removal of juniper trees in this area 

increased water yields though there are a few negative side 

effects such as slope instability and seepage erosion. Further, the unique geology of the site forces ground water to 

the surface, allowing gains in water yield to be readily 

USDA Forest Service Proceedings RMRS-P-9. 1999 
exploitable. Initial modeling efforts are at too coarse a scale 

for adequate predictive modeling. Higher resolution DTM's 

are required to examine spring sapping and other topographic features related to modeling at our site. 

Acknowledgments 

Special appreciation to Darrell Johnson and family for 

field assistance, a verbal history of the study area, and use 

of their private land. Norm Evenstad and Carlos Garcia of 

the NRCS for technical reports, aerial photographs, and 

information. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

References --------------------------------- Arthur, W. J. 1961. Unusual solution cavities in the Manning 

Canyon Shale near Fairfield, Utah Geol. Soc. Am. Bull. 72: 

767-768. 

Betson, R. P. 1964. What is watershed runoff? J. Geophysical Res. 

69: 1541-1552. 

Croft, M. 1956. The geology of the Northern Onaqui Mountains, 

Unpublished M.S. Thesis, Brigham Young University, Provo, UT. 

Dunne, T. and R. D. Black. 1970. Partial area contribution to storm 

runoff in a small New England watershed. Water Resour. Res. 6: 

1296-1311. 

Rigby, J. K. 1958. Geology of the Stansbury Mountains, Tooele 

County, Utah. Guidebook to the Geology of Utah no. 13, Utah 

Geological Society, Salt Lake City, UT. 

United States Department of Agriculture, Soil Conservation Service and Forest Service. 1988. Shambip River Basin Study, 

USDA, Salt Lake City, UT. 

199 
Erosion and Deposition in a Juniper 

Woodland: The Chicken or the Egg? 

Theresa M. Lowe 

James P. Dobrowolski 

Abstract-Maturejuniperwoodlands are characterized by spatial 

variability in hydrological conditions and microtopography. Coppice dunes (syn-hummocks or mounds) often occur beneath trees. 

These microtopographic features, sometimes reaching elevations of 

greater than one meter above the surrounding interspaces, typically 

are characterized by superior organic matter content and relatively 

fine-textured soils. This research is an attempt to identify the 

mechanisms involved in the production of the microtopographical 

differences. Differences in soil morphology and plant distribution 

between coppice dunes and interspaces were observed in and 

around backhoe trenches exposing soils in the coppice dunes and 

interspaces. 

When juniper canopies begin to mature and close, 

microtopographic elements of a hillslope become more pronounced. Beneath trees, mounds or "coppice dunes" are 

evident. These coppice dunes appear to decrease in elevation 

from the tree trunk outward and they are composed of 

relatively fine-textured soils with incorporated leaf litter. 

Within interspaces, soil surfaces can be as much as one 

meter (3.25 ft) lower than at the tree trunk and are covered 

by gravel. Heede (1987) found that the microtopography 

produced by tree coppices absorbed the energy of flowing 

water and restricted the sediment delivery downslope. With 

the inability to effectively measure erosion, little erosion 

data exists to refute or substantiate the philosophical differences involving claims of site degradation and soil loss (Price 

and Ridd 1991). Do sites that are dominated by mature 

juniper trees represent degraded or degrading systems? 

Researchers have postulated that juniper succession trajectories are currently in place and are likely to continue for 

future centuries due to tree longevity, resulting in a selfdestructive system (Carrara and Carroll 1979; Evans 1988; 

West and others, 1979). 

The general objective of this study is to examine the 

processes occurring in a juniper ecosystem to identify sediment source or sink relationships towards answering the 

need for custodial or active management. It will begin with 

the attempt to identify the formation properties of juniper 

coppice dunes and how they differ or relate to the tree 

interspaces. The surface morphology of the juniper-covered 

hillslopes will be described and an attempt to model the 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Theresa M. Lowe is a Graduate Research Assistant and James P. 

Dobrowolski is an Associate Professor of Rangeland Resources, Department 

of Rangeland Resources, Utah State University, Logan, UT 84322-5230. 

200 

potential flow paths will be made. The specific objectives 

include: 

1. To describe the soil morphology beneath the juniper 

trees and within the interspaces and the relationship to the 

vegetation. 

2. To survey the hillslope surfaces for small scale elevation 

differences between tree coppice dunes and interspaces. 

Study Area ________ _ 

The Clover Creek Watershed is located in northeastern 

Tooele County approximately 32 km (20 miles) south of 

Tooele, Utah (St. John Quad, Sect. 35, T.6S, R.6W). Two 

3.24 ha (8-acre) exclosures were established on land leased 

by cooperator Darrell Johnson to investigate differences in 

soil chemical, physical and biological characteristics beneath juniper trees and in tree interspaces. The study area 

straddles the semi-desert and upland climatic zones. Precipitation averages 30.98 cm (12 inches) each year with 

approximately 71 percent coming as snow and 29 percent as 

spring and summer thunderstorms. Temperatures range 

from -7 to 38°C (-19 to 101°F) throughout the year (Utah 

Climate Center, Johnson Pass, 1996). Soils were formed 

from alluvial deposits derived dominantly from limestone 

and were mapped as loamy-skeletal, carbonatic, mesic, 

shallow Petrocalcidic Palexerolls (formerly Aridic Petrocalcic 

Palexerolls) of the Borvant series (Soil Survey Staff, 1996; 

TrickIer and others, in press). The vegetation type is a 

juniper woodland integrated with a shrub steppe. The overstory is dominated by Utah juniper (Juniperus osteosperma) 

with an understory composed of microbiotic crusts and 

various grasses. Tree interspace can be divided into two 

categories. One type had dominants that include Wyoming 

big sagebrush (Artemisia tridentata ssp. wyomingensis) and 

gray rabbitbrush (Chrysothamnus nauseosus) with over 50 

percent cover and the understory composition similar to the 

juniper understory. The second interspace type had sparse 

vegetation with various grasses, microbiotic crusts and 

gravel. 

Analysis of Soil Morphology 

Four clusters of five soil pits (twenty soil pits) were 

established immediately outside of the exclosures. The 

exclosures will have long term experiments and would 

have been severely disturbed by the excavation of the pits 

within the exclosure. In each soil pit cluster, two pits were 

excavated in coppice dunes after tree removal, two pits were 

cut into adjacent interspaces and one pit was established in 

a nearby sagebrush stand. Some interspaces contained living and dead sagebrush plants. Sagebrush also appeared to 

occur in small coppice dunes. However, coppice dunes of 

USDA Forest Service Proceedings RMRS-P-9. 1999 
dead sagebrush were observed to be eroding apparently by 

wind, water or both. 

Surface topography and geomorphology of the two 

exclosures were characterized using a GTS-3D Geodetic 

Total Station. Vertical resolution with this instrument was 

approximately 0.001 m, with spatial resolution of 0.005 m 

Where visible, microtopography reflecting coalescence of 

surface runoff was be noted on maps (fig. 1). 

Soil characteristics such as depth of each horizon, depth to 

petrocalcic layer, petrocalcic layer thickness, pore sizes and 

abundance were recorded. Changes in soil color, structure 

and particle sizes were used to detect differences in horizons. 

Field and laboratory analysis ofthe chemical characteristics 

such as pH by color indicators and calcium carbonate equivalen t will be cond ucted . Vegetation analysis will be cond ucted 

to determine percent coverage. 

Results __________ _ 

Detailed surface mapping (fig. 1) illustrated the interfluve 

surfaces with juniper trees and fluvial deposits covered 

primarily by living and dead sagebrush. In figure 1, the 

sagebrush interspaces, which will be called fluves, are found 

in the linear depressions identified by the solid arrows. 

Small-scale changes in elevation and individual coppice 

dunes were visible. Field observations during rainfall-runoff 

events and the presence oflitterdams suggested that visible 

micromorphological depressions provide paths for water 

flow across the landscape. The next step will be to model the 

overland flow on these exclosures with varying water depth. 

Soils were highly variable in the study area. In general, 

the soil under the juniper trees had an organic horizon 

(table la) that was absent in the interspace and the fluve. 

There was a petro calcic horizon that appeared to restrict 

the downward growth of roots and impede water percolation 

and vertical nutrient flux. This horizon was present in the 

three pedons but at different depths. The sparsely vegetated 

interspace had the petrocalcic horizon starting at 26 cm and 

extending to 149 cm (table lc). The petrocalcic horizon under 

the juniper coppice dune was deeper, starting at 37.5 cm 

and extending to 106.5 cm (table la). The sagebrush fluve 

hada weakpetrocalciclayerextendingfrom 68 to 87 cm with 

roots occurring in horizontal fractures throughout the horizon (table Ib). The differences in depth indicate that water 

will most likely infiltrate deepest in the fluve with the best 

possibility of vertical distribution of nutrients , depending on 

the amount of rain and the intensity of the storm. 

The A horizon was shallowest in the interspace (13 cmtable lc) while the A horizon extended 14 cm and 30 cm 

under thejuniper and in the fluve, respectively (table la,b). 

Soil color helped to distinguish between horizons and assisted in the identification of the differences in horizon 

properties between coppice dunes and tree interspaces. The 

pits in the sagebrush fluves had a deeper soil with evidence 

of multiple stages of deposition. The soil had a calcic or 

weakly developed petrocalcic horizon. Although Davenport 

and others (1996) concluded that pinyon and juniper trees 

had no significant influence on the soil morphology in New 

Mexico, it appears from the preliminary findings that 

horizonation is different between coppice dunes, interspaces 

and the fluves in the Great Basin. This difference might 

influence the distribution of vegetation. Further investigations of the linkages between soil morphology, specifically 

the properties of the petrocalcic layers in relation to plant 

establishment and erosion potential are being conducted. 

Figure 1-Three-dimensional surface plot of coppice dunes, interspaces and fluves. Arrows indicate fluves with 

sagebrush. Individual coppice dunes are evident in the lower right. 

USDA Forest Service Proceedings RMRS-P-9. 1999 201 
202 

Table 1 a-The representative soil pedon description for Plot 1-301 juniper coppice dune observed on 9/4/97. 

The pedon for plot 1-301 is located under a juniper tree in St. John Quad, NE 1/4 of NE 1/4 sec. 35, T.6S, R.6W at an elevation 

of 5580 ft. The landform is a dissected fan composed of alluvium from limestone. There are no surface stones or rock fragments 

at this site. The slope is 5 percent with a northeast aspect. This pedon is well-drained with a water table that is deep. The site 

has a climate of aridic/mesic and supports vegetation such as: juniper and perennial grasses. Colors are for dry soil unless 

otherwise noted. 

This soil is classified as a loamy-skeletal, carbonatic, mesic, shallow Petrocalcidic Palexeroll 

Oi 

A 

AB 

BA 

Bk 

Bkm1 

Bkm2 

2Bkm3 

3-0 centimeters; black (1 OYR 2/1) moist; partially decomposed root mat; loose; many fine and very fine roots; 

violently effervescent with a pH of 7.7; abrupt, smooth boundary. 

0-6.5 centimeters; grayish brown (10YR 5/2) sandy loam, very dark brown (1 OYR 2/2) moist; moderate fine 

granular structure; slightly hard, very friable, slightly sticky and slightly plastic; few medium, common fine 

and many very fine roots; many very fine, common fine and few medium tubular pores; gravel 5 percent; 

violently effervescent with a pH of 8.1; clear, smooth boundary. 

6.5-14 centimeters; grayish brown (10YR 5/2) sandy loam, dark brown (7.5YR 3/2) moist; moderate medium 

subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common coarse, medium, very fine 

and fine roots; common very fine, fine, medium and coarse tubular pores; gravel 1 percent; violently effervescent 

with a pH of 8.3; clear, smooth boundary. 

14-21 centimeters; brown (10YR 5/3) sandy loam, dark brown (1 OYR 3/3) moist; moderate medium subangular 

blocky structure; soft, friable, slightly sticky and slightly plastic; few coarse, medium, fine and very fine roots; 

common very fine, fine and medium tubular pores, few coarse tubular pores; gravel 10 percent with calcium 

carbonate seams (5 percent by voL); violently effervescent with a pH of 8.4; clear, smooth boundary. 

21-37.5 centimeters; light brownish gray (10YR 6/2) very cobbly sandy clay loam, brown (10YR 4/3) moist; 

moderate medium subangular blocky structure; hard, very firm, sticky and plastic; common coarse, medium, fine 

and many very fine roots; many very fine tubular pores, common fine, medium and coarse tubular pores; gravel 10 

percent with calcium carbonate in pores and on rock faces (5 percent by voL); violently effervescent with a pH of 

8.3; clear, smooth boundary. 

37.5-74 centimeters; white (10YR 8/1) very cobbly loamy sand, very pale brown (10YR 7/3) moist; massive; 

extremely hard, extremely firm, indurated; common coarse, medium, fine and many very fine roots; many 

very fine and fine tubular pores, common medium and coarse tubular pores; gravel 25 percent and cobbles 

30 percent; violently effervescent with a pH of 8.1; clear, smooth boundary. 

74-106.5 centimeters; white (10YR 8/1) very gravelly coarse sand, very pale brown (10YR 7/3) moist; massive; 

extremely hard, extremely firm, indurated; few very fine, fine and medium roots; common very fine pores; common 

very fine tubular pores; gravel 55 percent with calcium carbonate seams and coating rock faces (30 percent by 

voL); violently effervescent with a pH of 8.8; clear, smooth boundary. 

106.5-121 centimeters; white (1 OYR 8/1) gravelly coarse sand, pale brown (1 OYR 6/3) moist; moderate medium 

platy structure; extremely hard, extremely firm, indurated; few fine roots; many very fine tubular pores; gravel 25 

percent and cobbles 1 percent with calcium carbonate seams and on ped faces (25 percent by vol.); violently 

effervescent with a pH of 9.2; clear, smooth boundary. 

The diagnostic characteristics of this pedon include: petrocalcic horizon (37.5-106.5 cm); mollic epipedon. 

Table 1 b-The representative soil pedon description for Plot 1-3Ew sagebrush fluve observed on 8/11/97. 

The pedon for plot 1-3Ew is located in a sagebrush fluves in St. John Quad, NE 1/4 of NE 1/4 sec. 35, T.6S, R.6W at an 

elevation of 5580 ft. The landform is a dissected fan composed of alluvium from limestone. The surface stone and rock at this 

site is 10 percent gravel. The slope is 5 percent with an easterly aspect. This pedon is well-drained with a water table that is 

deep, >228 cm. The site has a climate of aridic/mesic and supports vegetation such as: dying big sagebrush and perennial 

grasses. Colors are for dry soil unless otherwise noted. 

This soil is classified as a loamy-skeletal, carbonatic, mesic Xeric Petrocalcid 

A 

BAtk 

Bk 

2Bkm 

0-8 centimeters; brown (1 OYR 5/3) fine sandy loam, dark brown (10YR 3/3) moist; weak fine granular structure; 

soft, very friable, slightly sticky and nonplastic; common very fine, fine, few medium and coarse roots; many fine 

interstitial pores; gravel 1 percent; violently effervescent with a pH of 8.2; abrupt, smooth boundary. 

8-30 centimeters; light brownish gray (1 OYR 6/2) loam, dark brown (1 OYR 3/3) moist; weak medium to fine 

subangular blocky parting to granular structure; soft to slightly hard, friable, slightly sticky and slightly plastic; 

common very· fine and fine, few medium and coarse roots; common very fine and fine tubular pores, few medium 

and coarse tubular pores; gravel 2 percent; violently effervescent with a pH of 8.3; clear, smooth boundary. 

30-68 centimeters; light gray (1 OYR 7/2) loam, pale brown (10YR 6/3) moist; massive; extremely hard, friable, 

slightly sticky and slightly plastic; few fine, medium and coarse roots; few fine, medium and coarse tubular pores; 

gravel <1 percent; violently effervescent with a pH of 8.4; clear, smooth boundary. 

68-87 centimeters; very pale brown (10YR 8/2) very gravelly; pale brown (10YR 6/3) moist; massive; indurated; 

common very fine, fine and few medium roots; common fine tubular pores; gravel 40 percent; roots between Bkm 

fractures mostly horizontal; violently effervescent with a pH of 9.3; abrupt, wavy boundary. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
2Bk 

3BCk1 

4BCk2 

5BCk3 

87-175 centimeters; very pale brown (10YR 7/3) loamy sand, dark yellowish brown (10YR 4/4) moist; massive; 

hard, firm, nonsticky and nonplastic; few fine roots; many very fine and fine interstitial pores and few fine tubular 

pores; gravels 5 percent with thin calcium carbonate seams (1 percent by voL); violently effervescent with a pH of 

9.9; clear, smooth boundary. 

175-183 centimeters; very pale brown (1 OYR 7/3) extremely cobbly loamy coarse sand, yellowish brown (10YR 5/ 

4) moist; massive; slightly hard, friable, nonsticky and nonplastic; few fine roots; few fine tubular pores; gravels 30 

percent and cobbles 40 percent with clay/silt balls (2-3 mm, <1 percent by voL); violently effervescent with a pH of 

9.7; clear, smooth boundary. 

183-206 centimeters; very pale brown (10YR 7/3) sandy loam, yellowish brown (10YR 5/4) moist; massive; 

slightly hard, very friable, nonsticky and nonplastic; few fine roots; few fine tubular pores; gravel 1 percent with 

calcium carbonate seams (1 mm, 5 percent by voL); violently effervescent with a pH of 9.8; abrupt, smooth 

boundary. 

206-228 centimeters; pale brown (1 OYR 6/3) extremely cobbly loamy sand, dark yellowish brown (1 OYR 4/4) 

moist; single grain; loose, nonsticky and nonplastic; few fine roots; common fine pores; gravel 50 percent and 

cobbles 35 percent; violently effervescent with a pH of 9.2. 

The diagnostic characteristics of the pedon include: petrocalcic horizon (68-87), ochric epipedon. 

Table 1 C-The representative soil pedon description for Plot 1-312 sparsely vegetated interspace observed on 8/11/97. 

The pedon for plot 1-312 is located in the sparsely vegetated interspace in St. John Quad, NE 1/4 of NE 1/4 sec. 35, T.6S, 

R.6W at an elevation of 5,580 ft. The landform is a dissected fan composed of alluvium from limestone. The surface stone and 

rock at this site is 50 percent gravel. The slope is 5 percent with a northeast aspect. This pedon is well-drained with a water 

table that is deep, > 149 cm. The site has a climate of aridic, mesic and supports vegetation such as: cryptograms, perennial 

grasses and sparse sagebrush. Colors are for dry soil unless otherwise noted. 

This soil is Classified as a loamy-skeletal, carbonatic, mesic Xeric Petrocalcid 

A 

BA 

Bw 

Bw2 

Btkm 

Bkm1 

Bkm2 

2Bkm3 

2Bkm4 

0-5 centimeters; pale brown (1 OYR 6/3) very gravelly loam, brown (1 OYR 4/3) moist; weak medium platy parting 

to granular structure; hard, friable, Slightly sticky and slightly plastic; few very fine roots; few very fine and fine 

tubular pores; many very fine interstitial pores; upper 1-2 cm very few fine and very fine tubular and vesicular 

pores; gravel 40 percent; violently effervescent with a pH of 8.3; clear, smooth boundary. 

5-13 centimeters; light brownish gray (10YR 6/2) loam/silt loam, brown (10YR 4/3) moist; weak medium 

subangular blocky parting to very fine granular structure; hard, friable, slightly sticky and slightly plastic; 

common fine, medium, few coarse and very few very coarse roots; common fine and medium tubular pores, 

few very coarse and coarse tubular pores; gravel 1 percent; violently effervescent with a pH of 8.2; clear, 

smooth boundary. 

13-19.5 centimeters; pale brown (10YR 6/3) loam/silt loam, brown (10YR 5/3) moist; moderate medium to fine 

subangular qlocky structure; hard, friable, slightly sticky and slightly plastic; common fine, few medium and coarse 

roots; common fine, few medium and coarse tubular pores; gravel 5 percent; petrocalcic fragments 1 percent; 

violently effervescent with a pH of 8.2; clear, smooth boundary. 

19.5-26 centimeters; very pale brown (10YR 7/3), loam/silt loam, brown (1 OYR 5/3) moist; very hard, friable, 

slightly sticky and slightly plastic; common fine roots, few medium and coarse roots; few fine, medium and 

coarse tubular pores; violently effervescent with a pH of 8.2; abrupt, smooth boundary. 

26-37.5 centimeters; white (1 OYR 8/1), very pale brown (1 OYR 7/3) moist; platy crumbling to fine subangular 

blocky structure; weakly cemented; very hard, firm; few fine roots; few fine tubular pores; gravel 5 percent; root 

layer at boundary; violently effervescent with a pH of 8.4; abrupt, smooth boundary. 

37.5-68.5 centimeters; white (1 OYR 8/1), very pale brown (1 OYR 7/3) moist; platy crumbling to medium 

subangular blocky structure; weakly cemented; extremely hard, extremely firm; few fine, few medium and few 

coarse roots; few fine, few medium and few coarse tubular pores; roots in pores and fractures; root layer of few 

medium and very fine roots at boundary; gravel 10 percent; violently effervescent with a pH of 8.5; abrupt, smooth 

boundary. 

68.5-77.5 centimeters; white (10YR 8/2), very pale brown (10YR 7/3) moist; massive; extremely hard, extremely 

firm, indurated; gravel 10 percent; root layer of few medium, coarse and many fine roots at boundary; violently 

effervescent with a pH of 9.0; clear, smooth boundary. 

77.5-92 centimeters; white (10YR 8/2), light gray (1 OYR 7/2) moist; massive; extremely hard, extremely firm, 

indurated; gravel (fine, medium and a few coarse) 40 percent; violently effervescent with a pH of 9.0; clear, 

smooth boundary. 

92-149 centimeters; white (10YR 8/1), very pale brown (10YR 7/3) moist; massive; extremely hard, extremely 

firm, indurated; gravel (coarse) 50 percent; violently effervescent with a pH of 9.3. 

The diagnostic characteristics of this pedon include: petrocalcic horizon (26-149 cm), ochric epipedon. 

USDA Forest Service Proceedings RMRS-P-9. 1999 203 
References __________________ __ 

Carrara, P. E.; Carroll, T. R. 1979. The determination of erosion 

rates from exposed tree roots in the Piceance Basin, Colorado. 

Earth Surface Processes and Landforms. 4: 307-317. 

Davenport, D. W.; Wilcox, B. P.; Breshears, D. D. 1996. Soil morphology of canopy and intercanopy sites in a pinon-juniper woodland. Soil Science Society of America Journal. 60: 1881-1887. 

Evans, Raymond A. 1988. Management of pinyon-juniper woodlands. Ogden UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. General Technical Report, INT-249. 

Heede, Burchard H. 1987. The influence of pinyon-juniper on 

microtopography and sediment delivery of an Arizona watershed 

Ogden UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station. General Technical Report, 

RM-149: 195-198. 

204 

Price, Kevin P.; Ridd, M. K. 1991. Detection of soil erosion within 

pinyon-juniper woodlands using thematic mapper (TM) satellite 

data. ACSMlASPRS/Auto Carto 10 Meetings. March 24-29, 

Baltimore MD. 

Soil Survey Staff. 1996. Keys to Soil Taxonomy, Seventh edition. 

USDA Natural Resources Conservation Service. US Government 

Printing Office, Washington, D.C. 

TrickIer, D. and others. [In press.] Tooele County Soil Survey. 

Utah Climate Center. 1996. Precipitation Data for Johnson Pass. 

Utah State University. 

West, Neil E.; Tausch, R. J.; Rea, K. H.; Tueller, P. T. 1979. 

Phytogeographic variation within juniper-pinyon woodl.ands of 

the Great Basin. In: Harper, K. T.; Reveal, J. 1. coordmators. 

Intermountain Biogeography: A Symposium. Great Basin Naturalist Memoirs No.2. Provo, UT: Brigham Young University 

Press: 119-136. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Response of Bighorn Sheep to PinyonJuniper Burning Along the Green River 

Corridor, Dagget County, Utah 

Charles L. Greenwood 

Sherel Goodrich 

John A. Lytle 

Abstract-Rocky Mountain bighorn sheep (Ovis canadensis canadensis) within the Green River Corridor have shown a high 

preference for burned areas within the pinyon pine (Pinus edulis) 

and juniper (Juniperus osteosperma and J. scopulorum) belt and 

within ponderosa pine (Pinus ponderosa) communities. Burns located within or adjacent to steep rocky habitat, and within core 

bighorn use areas, received significantly higher use than nonburned areas. Increased use of an area occurred where fire left more 

open areas with a reduced density of live or standing dead trees. 

Positive response has been found in small burns of 5 acres to large 

burns of 600 acres or more. Less significant use was observed on 

burn areas that were not within the core bighorn sheep area, or at 

sites with dense standing dead pinyon-juniper. Bighorn group size 

was significantly larger in burned areas. 

Rocky Mountain bighorn sheep (Ovis canadensis canadensis) were reintroduced on Bare Top (also known as 

Bear) Mountain along the Green River Corridor in 1983-

1984. Various habitat treatments have been applied to this 

area to improve and expand bighorn habitat. Historically, 

Native Americans used fire to maintain desired habitat for 

game species such as bighorn sheep, which they placed high 

value on as a resource. 

Smith (1992 and 1996) studied this bighorn herd in 1986-

1988, and in 1991. He found the most highly preferred 

habitats were burned areas dominated by grasses. He repeatedly found bighorn sheep in older burned areas and 

areas with sparse or intermediate cover of trees within the 

pinyon pine (Pinus edulis) and juniper (Juniperus 

osteosperma utahensis and J. scopulorum) belt, and at the 

interface of this belt with ponderosa pine (Pinus ponderosa) 

communities. Smith (1996) studied the response of Bare Top 

bighorns to clearcutting and prescribed burns applied to 

cliff-side habitat in 1989. He found that bighorns responded 

favorably to both habitat treatments by expanding range 

use and distributions into formerly unused areas, and that 

bighorns favored clearcuts twice as much as burned areas. 

Subsequent monitoring (1995-1997) by the Utah Division of 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Charles L. Greenwood is a Wildlife Biologist, Northeastern Region, Utah 

Division of Wildlife Resources, Vernal, UT 84078. Sherel Goodrich is Forest 

Ecologist, Ashley National Forest, Forest Service, U.S. Department of Agriculture, Vernal, UT 84078. John A. Lytle is Habitat Biologist, Utah Division 

of Wildlife Resources, Vernal, UT 84078. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Wildlife Resources (UDWR) continues to show a stronger 

preference for burned and open areas over those occupied by 

dense trees. 

Smith (1992) also looked for bighorn sheep in recently 

burned pinyon-juniper areas with a high density of standing 

dead trees. He found that the bighorns generally avoided the 

areas that had a high density oflive or standing dead trees. 

He considered a high density of live or standing dead trees 

to reduce the visibility of bighorns to intolerable levels. 

Study Area ________ _ 

The principal area of study is on and around Bare Top 

Mountain which is wi thin the Green River Corridor, Daggett 

County, Utah. The top ofthe mountain is comparatively flat 

with Red Canyon and Flaming Gorge Reservoir on the east, 

south, and west sides. Red Canyon is a deep canyon with 

associated side canyons. It was cut by the Green River which 

runs through the north flank of the Uinta Mountains. These 

steep rocky canyons which have been cut through Precambrian materials of the Uinta Mountain Group, Weber Sandstone, and other geologic formations, provide important 

habitat for bighorn sheep. Steep and cliffy canyon walls with 

warm exposures provide winter forage when snow is deep on 

the top. These steep areas are also important during the 

lambing season, and for escape cover (Smith 1992). Wild and 

prescribed fire has occurred on top of the mountain and 

along the canyon walls (fig. 1,2). Burns range in size from 5 

acres to over 600 acres. Clearcut logging also occurred in 

1989 on top of the mountain. 

Pinyon andjuniper are well adapted to the steep and rocky 

canyon walls with warm exposures. The density of pinyonjuniper is largely a function of fire history. Fire potential is 

dependent upon pinyon-juniper density and understory conditions. Many places along the canyon have intermediate 

densities of pinyon-juniper trees, where a high percent of 

exposed rock has reduced tree and understory densities 

necessary to carry fire. In other places fuel conditions have 

enabled fire to occur, indicating fire to be an important part 

of the ecology of the area. 

The top of the mountain contains ponderosa pine with 

associated mountain brush and grass communities of sagebrush (Artemesia tridentata wyomingensis), bitterbrush (Purshia tridentata), snowberry (Symphoricarpus spp.), ceanothus (Ceanothus spp.), wheatgrasses (Agropyron spp.), sheep 

fescue (Festuca spp.), and needlegrass (Stipa spp.). Pinyonjuniper also grows on top, however, dense stands have not 

commonly developed there. Fuels and other conditions have 

effectively carried fires and reduced pinyon-juniper presence. 

205 
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Figure 1-Bare Top bighorn sheep locations (1986-1991), in relation to pinyon-juniper burns, Daggett County, Utah (Smith 1992 and 1996). 
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". ._\ Figure 2-Bare Top bighorn sheep locations (1995-1997), in relation to pinyon-juniper burns, Daggett County, Utah. 

1-
Methods ----------------------------------- New pinyon-juniper areas were burned in 1992 in a 

cooperative effort with the U.S. Forest Service and the 

UDWR. Both burns were located in steep rocky habitat 

considered to be within the core bighorn use area. The core 

bighorn use area was from North Skull Creek west along Red 

Canyon and north to the Boars Tusk (fig. 1,2). Bighorn use 

of the new pinyon-juniper burn areas before and after 

burning was compared. Comparisons were made between 

1995-1997 bighorn location data, and 1986-1991 bighorn 

locations from Smith (1992 and 1996). 

Bighorn sheep were located primarily using radio telemetry from 1995-1997. Radio-collared bighorns were located 

from the ground, boat, and fixed-wing aircraft. Ground 

surveys were performed up to 3 times per month, and fixedwing surveys once per month. In addition, bighorn locations 

from helicopter trend counts and incidental observations 

were also used. Bighorn group size, classification (rams, ewes, 

and lambs), and burn category was documented for each 

observation. Bighorn locations and burns were digitized into 

a geographic information system (GIS). Smith (1992) also 

used radio telemetry for surveys from 1986-1988. Smith 

(1996) recorded visual observations of bighorns in 1991 made 

along an established walking transect (radio telemetry was 

not used during his 1991 walking transect survey). 

The hypothesis, that bighorn sheep use different age 

burns and non-burned areas in proportion to the area of 

occurrence, was examined using a chi-square goodness-of-fit 

test. Selection or avoidance of individual burned or nonburned areas was examined using Bonferroni normal statistics (Neu and others 1974). A comparison of mean bighorn 

group size between burned and non-burned areas was conducted using a Student's t-test. 

Results ------------------------------------

Bighorn sheep continued to use the more open, steep and 

rocky habitat during 1995-1997. Forty-three percent of all 

bighorn locations from 1995-1997 occurred in burned 

areas. Twenty-two percent ofthe bighorn locations occurred 

in the new burn areas. Smith (1992 and 1996) found less 

than 2 percent of his bighorn locations in these areas prior 

to burning. The Hideout burn is 581 acres and was seeded 

with a mix of grasses and forbs. The Lakeshore burn is 64 

acres, and was never reseeded. The core bighorn area was 

used to test the hypothesis that bighorns utilized burned 

areas of different ages, and non-burned areas, in exact 

proportion to their occurrence. Chi-square analysis (goodness-of-fit test) showed a significant difference between the 

observed and expected bighorn observations for burned and 

non-burned areas (X2 = 133.54 >X2 0.99 (4) = 13.27). Thus the 

hypothesis was rejected. Next, the analysis technique developed by Neu and others (1974) was used to determine 

preference or avoidance of burned and non-burned areas. 

Comparisons of the expected proportion of bighorn observations, to the 95 percent confidence interval on the observed 

proportions of bighorn observations, were made (table 1). 

Bighorns were observed in burns, ranging in age from the 

1970's to 1992, significantly more than expected (42 percent 

of the bighorn observations were in these more recent burns, 

although only 14 percent were expected). Old burns ranging 

in age from the 1920's to 1950's were used in proportion to 

their availability (1.5 percent of the bighorn groups were 

observed, with 2.0 percent expected). Non-burned areas 

were used significantly less than expected (57 percent of the 

bighorn observations occurred in non-burned areas, with 84 

percent expected). 

Bighorn group size comparisons between burned and nonburned areas found burned areas to have a mean (SE) group 

size of 8.3 (0.84) bighorns, and non-burned areas 5.0 (0.77) 

bighorns. Burned areas had a significantly higher bighorn 

group size than non-burned areas (t = 2.85, 71 df, P < 0.01). 

Discussion -------------------------------- Our study shows that bighorn sheep will use new pinyonjuniper burns given the right circumstances. The Lakeshore 

burn is located on the east side of the Thumb area next to 

Flaming Gorge Reservoir in cliffside habitat. Prior to burning, trees were cut and piled to increase fire transmission. 

After burning, few standing dead trees remained allowing 

good visibility for bighorns. The Lakeshore burn was located 

next to the Thumb area which already received concentrated 

bighorn use. 

The Hideout burn is located in steep rocky terrain, along 

Red Canyon, on the southwest side of Bare Top, within the 

core bighorn use area. In parts of the burn, pinyon-juniper 

trees were sparse enough that burned skeletons do not 

reduce visibility for bighorns. Most of the bighorn observations in the Hideout burn are on the west ridge which had 

a lower density of pinyon-juniper prior to burning. 

Table 1--0bserved and expected frequencies of bighorn observations in relation to pinyon-juniper burns, Bare Top Mountain, Daggett County, 

Utah,1995-1997. 

Burn Observed 

categories Acres N 

1992 Burns 650 44 

1980's Burns 190 13 

1970's Burns 578 28 

1920-50's Burns 201 3 

Non-Burned 8,381 115 

Total 10,000 203 

aOerived from the acres of each burn category. 

bFrom Neu and others (1974). 

Proportion (Pi) 

0.217 

0.064 

0.138 

0.015 

0.566 

1 

EXQected a 95 percent confidence Selection 

N Proportion interval on Pi b behaviorc 

13 0.065 0.143 < Pi < 0.291 Preferred 

4 0.019 0.020 < Pi < 0.108 Preferred 

12 0.058 0.076 < Pi < 0.200 Preferred 

4 0.020 - 0.007 < Pi < 0.037 Indifferent 

170 0.838 0.476 < Pi < 0.656 Avoided 

203 1 

cBurn categories preferred were used significantly more than expected; burn categories indifferent used as expected; burn categories avoided used significantly less. 

208 USDA Forest Service Proceedings RMRS-P-9. 1999 
Bighorns tend to avoid parts of the burn where the skeletons are dense. 

Smith (1992) recommended against using pinyon-juniper 

burns to create or enhance bighorn habitat. He found bighorn sheep had preference for areas which provide high 

visibility. The most highly preferred habitats were older 

burned areas dominated by grasses. He found bighorns 

avoided high and intermediate densities of pinyon-juniper 

stands. This avoidance included recently burned stands 

with high densities of standing dead trees. He observed that 

older burned areas with low densities of trees were preferred 

by bighorns. This was consistent with other studies that 

reported bighorns to seek burned areas. Smith (1992) also 

found the diets of bighorns in this area were comprised of 

79.2 percent graminoids, 6.9 percent forbs, 13.0 percent 

shrubs, and 1 percent conifers. The rim of Red Canyon was 

considered by Smith (1992) to be highly important habitat 

for the bighorns. He found that 95 percent of all observed 

bighorn activity was confined to steep cliff complexes or was 

within 300 meters of them. 

Smith (1996) found that bighorns responded favorably to 

both clearcut logging and prescribed burns by expanding 

range use and distributions into formerly unused areas. He 

found that bighorns favored clearcuts twice as much as 

burned areas. 

Three criteria must be met when planning pinyon-juniper 

burns to enhance bighorn use and expand habitat. First, new 

pinyon-juniper burns must be located within the core bighorn sheep use area. Second, new burns must be within or 

immediately adjacent (within 300 m) to steep rocky escape 

terrain. Third, part of the area to be burned should have a 

lower density of trees, so that the burned skeletons will not 

reduce visibility for bighorn sheep. 

Results of our study indicate that Bare Top bighorns did 

not significantly use new pinyon-juniper burns north and 

east of North Skull Creek during Smith's (1992) study 

primarily beca use these new burns were not within the core 

bighorn sheep area and remaining tree skeletons were dense 

and reduced bighorn visibility. Bighorns were not found to 

utilize these same burns during our study for the same 

reasons. It is hoped that as standing dead tree skeletons fall 

and decay, bighorn visibility and use will increase. 

Smith (1992) observed significant bighorn use on an old 

burn (from the 1920's) at the mouth of North Skull Creek. 

The Thumb area was burned in 1978 by a wildfire and 

received the highest concentration of bighorn use during 

Smith's study (1992). 

A significant shift in bighorn use to the new 1992 pinyonjuniper burned areas occurred. The Thumb continues to 

receive significant bighorn use. The new Hideout burn now 

receives comparable bighorn use to the Thumb. 

Conclusions ------------------------------- Small burns as well as larger burns were selected during 

all studies. Documented observations verify high bighorn 

selectivity for burned areas which result in early seral, open 

communities. Habitat values for bighorn sheep within the 

pinyon-juniper belt are much higher in early seral communities than in mature pinyon-juniper stands. Visibility is 

indicated to be a major factor in habitat selection. Conditions 

that favor greater visibility are also favorable conditions for 

quantity and quality of forage for the bighorns. The high 

USDA Forest Service Proceedings RMRS-P-9. 1999 

percentage of graminoids and low percentage of conifers in 

the diets of bighorns found by Smith (1992) are consistent 

with the concept that early seral communities are of greater 

value to bighorns than communities dominated by trees. 

Management Implications 

Valuable bighorn sheep habitat is associated with early 

seral plant communities in steep rocky terrain, characterized by good visibility, abundant grasses and grasslike 

plants, and low density of trees and tall shrubs. 

As pinyon-juniper have the capacity to dominate much of 

the landscape, fire or other disturbances will be required to 

maintain valuable bighorn habitat. Disturbance intervals 

short enough to prevent tree dominance is essential to the 

maintenance of this habitat. Studies in burned sites within 

the pinyon-j uni per belt of the Green River Corridor (Goodrich 

and Barber 1998, these proceedings) indicate a fire frequency of 50 or more years would likely keep tree density 

and stature at levels preferred by the bighorns. However, 

shorter intervals might be required to keep shrub density 

and stature within levels preferred by the bighorns. Fire 

intervals of 20-25 years (Houston 1973) and 10-40 years 

(Winward 1991) have been suggested within the inherent 

range of variability for montane sagebrush communities. 

Fire intervals of 20-25 years are indicated to keep density 

and stature of shrubs at levels favorable for bighorn sheep 

habitat. 

Burning outside core bighorn use areas in mature, dense 

stands of pinyon-juniper should not be expected to immediately increase available bighorn habitat. Re-burning such 

dense stands or using additional mechanical treatments, at 

appropriate intervals, will create and maintain open, early 

seral communities, increasing its value for bighorns. Expansion of habitat for bighorn sheep in this study area will 

depend largely on prescribed burning or other treatments 

that reduce the presence oflive pinyon andjuniper as well as 

tree skeletons remaining after fire. Maintenance of bighorn 

habitat will be highly dependent on repeated treatments. 

Bighorn sheep densities will be low without such actions. 

References --------------------------------- Goodrich, S.; Barber, B. This proceedings. In: Monsen, Stephen B.; 

Stevens, Richard; Tausch, RobinJ.; Miller, Rick; Goodrich, Sherel, 

comps. 1998. Proceedings: ecology and management of pinyonjuniper communities within the Interior West; 1997 September 

15-18; Provo, UT. Proc. RMRS-P-OOO. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Houston, D. B. 1973. Wildfires in northern Yellowstone National 

Park. Ecology. 54: 1111-1117. 

Neu, C. W.; Bryers, C. R.; Peek, J. M. 1974. A technique for analysis 

of utilization-availability data. J. Wildlife Manage. 

38: 541-545. 

Smith, T. S. 1992. The bighorn sheep of Bear Mountain: ecological 

investigations and management recommendations. Ph.D. Thesis, Brigham Young Univ., Provo, UT. 425 pp. 

Smith, T. S. 1996. Draft Publication: Response of Rocky mountain 

bighorn sheep to clear'cut logging and prescribed burning in 

Northeastern Utah. 22 pp. 

Winward, A. H. 1991. A renewed commitment to management of 

sagebrush grasslands. In: Miller, R. F., editor. Management of 

sagebrush steppe. Special Rep. 880. Corvallis, OR: Oregon State 

University Agricultural Experiment Station: 2-7. 

209 
Importance of Western Juniper Communities 

to Small Mammals 

Mitchell J. Willis 

Richard F. Miller 

Abstract: We investigated the composition and relative abundance 

of small mammals in western juniper (Juniperus occidentalis) 

woodlands of southeast Oregon in the spring of1993 and 1995-97 by 

snap trapping recently cut woodlands, shrub dominated sites, and 

adjacent uncut (both mid-successional and old-growth) juniper 

sites. The number of captures were almost. always higher in the cut 

sites than in the uncut sites, but results were mixed in the shrub/ 

tree comparisons. The number of species captured was higher in 

shrub sites compared to old growth woodland sites. We believe 

structure provided by robust understory vegetation and the overhanging juniper skeletons provided superior security and forage for 

small mammals in the cut and dropped sites. 

The issue of juniper (Juniperus sp.) encroachment, conversion, and subsequent impacts of community structural 

changes on small mammals has been of increasing interest 

by resource managers in recent years. Although research 

has been conducted on the direct effects of juniper on forage 

productivity, plant composition and structure, and impacts 

on big game, little has been directed toward small mammals 

associated with western juniper (J. occidentalis). 

Of the estimated 341 animal species found in southeastern Oregon (Maser and others 1984), 95 have been reported 

to occur in juniper steppe (Puchy and Marshall 1993). 

Juniper steppe is defined as western juniper woodlands, 

typically having a sagebrush (Artemisia sp.) understory. 

The westernjuniperlsagebrushlbunchgrass community had 

the third largest number of the 341 total wildlife species 

from the 16 general plant communities Maser and others 

(1984) described in southeastern Oregon. Puchy and Marshall 

(1993) also reported large numbers of wildlife use juniper 

steppe. However, both of these reports were based on minimal data and written as guidelines. These reports lumped a 

broad range of transitional phases of juniper succession in 

shrub steppe across a wide variety of environmental variables, both of which affect plant community structure, composition, and function (Miller and others, this symposium). 

Juniper-shrub steppe communities described in the literature are typically shrub-steppe communities in various 

stages of woodland conversion. Shrubs and some perennial 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Mitchell J. Willis is a Wildlife Biologist and Richard F. Miller is a 

Professor of Range Management, Eastern Oregon Agricultural Research 

Center, Oregon State University, HC71, 4.51 Hwy 205, Burns, OR 97720. 

210 

grasses and forbs are lost as woodlands approach full 

development, changing the structural characteristics of 

the understory (Miller and others, this symposium). 

Few studies have evaluated the effects of juniper woodland development or conversion in shrub steppe communities on nongame use, and most ofthese have been conducted 

in pinyon (Pinus sp.)-juniper communities. Baker and 

Frischknecht (1973) examined small mammal changes relative to clearing and seeding in pinyon-juniper communities 

in Utah. They found large increases in white footed deer 

mice (Peromyscus maniculatus) and Great Basin pocket 

mice (Perognathus parvus) in cut areas for the first three 

years after treatment, followed by a reduction to a population level still above that before treatment. Turkowski and 

Reynolds (1970) found 1.2-4.0 times as many rodents on 

treated (cut) plots over untreated plots three years after 

treatment in the same type on the Kaibab Platea u in Arizona. 

In pinyon-juniper woodlands of northeast Nevada, Mason 

(1981) found rodent numbers increased while species diversity decreased on burned pinyon-juniper sites during the 

first two years following treatment; both bird numbers and 

diversity increased on burned areas in these woodlands over 

comparable unburned areas. O'Meara and others (1981) 

noted small mammal abundance in Colorado was higher in 

chained pinyon -juni per woodland than in control plots. They 

suggested adverse effects on nongame wildlife could be 

minimized by favoring survival of shrubs and young trees, 

retaining selected cavity trees, and limiting widths of clearings when chaining. O'Meara and others (1981) also found 

higher bird densities in unchained areas than in chained 

areas. Sedgwick and Ryder (1987) found small mammal 

species richness and total captures greater on chained versus unchained plots of pinyon-juniper in Colorado. Seven of 

the 16 most common bird species in the area used the control 

plot more, while only one species used the chained plot more. 

Severson (1986) found total numbers of small mammal 

species significantly greater on all treated areas compared 

to untreated pinyon-juniper woodlands 13-18 years posttreatment. Individual species and groups responded differently to the tree removal manipulations and methods of 

slash disposal. Grassland rodents as a group were more 

abundant where the overstory and slash had been removed, 

however, wood rats (Neotoma sp.) and brush mice (Peromyscus boylii) were greatest where the slash remained on the 

site. Pinyon mouse (P. trueii) and rock mouse (P. difficilus) 

preferred the thinned site, where slash remained on site. 

Austin and Urness (1976) found few differences with respect 

to total rodent numbers and weight in a comparison among 

seven pinyon-juniper types. 

The apparent conflicting results of small mammal and 

bird responses to woodland treatment is probably largely 

due to the limited vegetation data collected in these studies. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Juniper and pinyon-juniper woodlands occur across a wide 

variety of spatial and temporal conditions in the Intermountain west (Miller and others, this symposium; Tausch and 

others, this symposium). Woodland structure and composition prior to treatment, and succession following treatment 

will likely significantly affect small mammal and avian 

populations. 

We investigated small mammal and bird composition and 

relative abundance in southeast and central Oregon, northwest Nevada, and northeast California in 1993 and 1995-97. 

In this paper, we compare small mammal populations between cut and uncut stands of mid-aged western juniper 

woodlands, old growth woodlands with adjacent shrubland, 

and also mid-aged stands with the old growth stands in 

southeast and central Oregon. 

Study Areas ________ _ 

Page Ranch: Closed Woodland vs. Cut 

The Page Ranch study area was located in Grant County, 

Oregon, along Warren Creek at about 4,600 ft with northwest 20 percent slopes. Treated sites were about 25 acres in 

size. Vegetation was a mountain big sagebrush (Artemisia 

tridentata ssp. vaseyana)/ Idaho fescue (Festuca idahoensis) 

community. The juniper stand was fully developed, about 

40 percent canopy cover, 100-130 trees/acre, with sparse 

understory shrubs. Perennial grasses and forbs had higher 

cover values in cut sites, but were common on both. Three 

treatment blocks were cut and the trees left in place during 

the fall of 1992. Sampling commenced in the spring of 1993, 

and was repeated in 1995-97. 

Krumbo Ridge: Mid-transitional JuniperShrub Steppe vs. Thinned 

The Krumbo Ridge study area was located at about 

5,000 ft on Steens Mountain, Harney County, Oregon. 

Slopes were generally northerly and less than 2 percent. The 

three uncut sites were mid-transitional woodlands with 

10-20 percent tree canopy cover and 100 trees/acre, 7-15 

percent shrub cover, and 5-10 percent perennial herbaceous 

cover. The three cut sites were thinned to 2-3 trees/acre 

(1-2 percent canopy cover) in the spring of1995. Understory 

vegetation was characterized by mountain big sagebrush 

and Idaho fescue. 

Juniper Mountain: Old Growth vs. Shrub 

Steppe 

The Juniper Mountain study area was located in Harney 

and Lake Counties at about 6,000 ft. All sites were on 

southeast aspects with 20 percent slopes. The woodland 

sites were old growth ranging from 400 to 1,000 years old 

and had 30-35 percent crown closure. Dead and down material was relatively abundant with many cavities. Shrub 

cover under the trees was less than 1 percent. The shrub 

sites had 35 percent cover of mountain big sagebrush. 

Abundant herbaceous plants were bluebunch wheatgrass 

(Agropyron spicatum), Thurber's needlegrass (Stipa 

thurberiana), and bottlebrush squirrel tail (Sitanian hystrix). 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Green Mountain: Old Growth Juniper 

Woodland vs. Shrub Steppe 

The Green Mountain study area was located in Lake 

County Oregon at 5,000 ft. Sites were southeast aspects 

with <5 percent slopes. The woodland canopy was more open 

with slightly less dead and down woody material and fewer 

cavities than Juniper Mountain. Tree canopy ranged from 

10-15 percent, shrub cover was <1 percent, and herbaceous 

cover 10 percent. The adjacent shrub sites burned about 

50 years ago. Shrub cover was 15 percent and herbaceous 

cover was 10-15 percent. 

Methods _________ _ 

Small mammal trapping was conducted in permanently 

marked grids centered within each site. Museum Special 

traps were set within 1 m of flags placed in a 10 x 10 array at 

5 m intervals totaling 100 traps/grid. Traps were baited with 

peanut butter and rolled oats. At each study area, treatments and controls were repeated three times resulting in 

3,000 trap-nights for each study area. Traps were set on day 

1, checked in the early morning on days 2-4, and pulled after 

checking on day 5. Trapping was conducted May-early July. 

The status of each trap was recorded daily. Captured mammals other than white footed deer mice were placed in plastic 

bags with plot number, treatment, station, and date recorded on the outside, cooled on ice, and later identified. 

White footed deer mice were removed from traps and left in 

the area in deference to hantavirus concerns. 

Museum Special snap traps were used in lieu oflivetraps. 

While capture selectivity may exist among trap types (Fowle 

and Edwards 1954), snap traps have been utilized extensively and effectively (Johnson and Keller 1983). Snap traps 

were found more effective than pitfall traps for deer mice and 

chipmunks (Tamias sp.) (McComb and others 1991), both 

common to juniper woodlands (Johnson and Keller 1983). 

Hayward and Hayward (1995) found capture rates between 

pit and snap traps were generally quite similar for the most 

common species in their work in central Idaho. We would 

have used pitfall and rat-traps as well, but logistics and 

finances limited effort to museum specials. 

Results __________ _ 

Fourteen species representing four orders of small mammals were captured (table 1) from the 30,000 trap-nights 

of study. We had 898 total captures (x = 34 trap-nights/ 

capture, range = 16-86). The white footed deer mouse was 

the most often captured species (n = 614; 68.4 percent), 

followed by yellow pine chipmunk (n = 122; 13.6 percent, and 

Great Basin pocket mouse (n = 81; 9 percent). 

Cut versus Uncut 

Seven trapping sessions were conducted comparing cut 

versus uncut sites (Page Ranch and Krumbo Ridge). Although the difference was not significant (P = 0.11), between 

cut and uncut sites across the two study locations, in all 

but one instance (Krumbo Ridge 1995), there were more 

211 
Table 1-Small mammals captured at Page Ranch, Krumbo Ridge, Juniper Mountain, and Green 

Mountain in Eastern Oregon, 1993, 1995-97. 

Location 1993 

Page Ranch (Uncut vs. cut) 

Long-tailed meadow mouse 0 0 

Montane meadow mouse 0 1 

Bushy-tailed wood rat 0 0 

Canyon mouse 0 0 

White-footed deer mouse 19 23 

Great Basin pocket mouse 1 

Yellow pine chipmunk 0 

U:t:rthern pocket gopher 0 

Western jumping mouse 0 

Krumbo Ridge (Uncut vs. Cut) 

Long-tailed meadow-mouse 

Montane meadow mouse 

White-footed deer mouse 

Great Basin pocket mouse 

Vagrant shrew 

Yellow pine chipmunk 

Mountain cottontail 

Northern pocket gopher 

Western jumping mouse 

Juniper Mountain (Shrub vs. Tree) 

Long-tailed meadow mouse 

Montane meadow mouse 

Ermine 

White-footed deer mouse 

Great Basin pocket mouse 

Yellow pine chipmunk 

Northern pocket gopher 

Green Mountain (Shrub vs. Tree) 

Ord kangaroo rat 

Desert wood rat 

White-footed deer mouse 

Great Basin pocket mouse 

Yellow pine chipmunk 

aSignificantly different. P = 0.005 

bSignificantly different. P = 0.0132 

cSignificantly different. P = 0.0001 

dSignificantly different. P = 0.0011 

eSignificantly different. P = 0.0476 

'Significantly different. P = 0.0047 

9Significantly different. P = 0.0187 

hSignificantly different. P = 0.0187 

iSignificantly different. P = 0.0457 

iSignificantly different. P = 0.0059 

kSignificantly different. P = 0.0122 

'Significantly different. P = 0.0086 

mSignificantly different. P = 0.0276 

nSignificantly different. P = 0.0005 

captures in the cut blocks (uncut x = 31.71, cut x = 57.43). 

The number of species encountered (species richness) in 

trapping sessions was greater three times in cut sites, two 

times in uncut sites, and tied twice. The greatest number of 

species encountered (uncut treatment at Page Ranch, 1995) 

was eight, and two was the lowest (2 other uncut treatments 

at Page Ranch, 1993,1997). Mountain pocket gophers 

(Thomomys talpoides) and western jumping mice (Zapus 

princeps) were not caught in cut sites. 

212 

1 

4 

0 

0 

1995 1996 1997 

1 0 0 0 0 0 

2 34a 0 5b 0 0 

1 0 0 0 0 0 

1 0 0 0 0 

36 86 C 35 72 d 9 18 

2 5 1 4 0 3 

1 158 1 f 11 2 3 

1 0 1 0 0 0 

0 0 0 0 0 0 

0 0 0 3 0 2 

1 1 1 1 0 1 

15 12 25 35 25 27 

2 1 8 6 6 3 

0 0 0 1 0 0 

5 8 13 8 3 4 

0 0 0 0 0 3 

1 0 2 0 0 0 

0 0 1 0 0 0 

0 0 3 0 

2 0 5 Oi 

0 0 1 0 

59 47 26 11 

9 29 12 1i 

3 4 1 16k 

1 0 0 1 

1 0 

0 1 

10 241 

12 2 m 

1 19n 

The lack of response of small mammals to cutting across 

the two areas is partially due to differences in woodland 

structures between the two locations. When evaluated within 

location, differences in small mammal abundance and 

diversity show up where the juniper woodland is fully 

developed and shrubs have been lost in the understory. 

Eight different species were captured over the four years 

of study in the closed post-settlement juniper woodland and 

adjacent cut plots at Page Ranch. Montane meadow mice, 

USDA Forest Service Proceedings RMRS-P-9. 1999 
white footed deer mice, and yellow pine chipmunks were 

significantly (P = 0.005, 0.0001, and 0.0476 respectively) 

more common in cut sites in 1995. This pattern held in 1996 

as well (P = 0.0132, 0.0011, and 0.0047). There were consistently (but non-significant, P = 0.125) more captures in the 

cut blocks (uncut x = 28.5, cut x = 71.5) over the four years 

of study. However, in the mid-transitional juniper-shrub 

steppe and thinned sites at Krumbo Ridge, no distinctions or 

consistent patterns were noted between treatments or 

years. Shrub-steppe structural characteristics were present 

in both treatments. Nine different species were captured 

over the three years of study. 

Shrub versus Woodland 

Three trapping sessions were conducted comparing shrub 

dominated sites with adjacent old growth juniper woodlands. There were significantly (P = 0.032) more mammals 

captured in shrub sites at Juniper Mountain (shrub x = 61 

captures, woodland x = 41 captures), while at Green Mountain, more were taken in woodland sites (shrub = 61 captures, 

woodland = 41 captures). Eight species were captured in 

shrub sites, and five in woodland sites. 

At the Juniper Mountain area, there were significantly 

more Great Basin pocket mice in the shrub sites in 1996 

(P = 0.0187). In 1997, there were significantly more montane meadow mice (P = 0.0457), Great Basin pocket mice 

(P = 0.0059), and fewer yellow pine chipmunks (P = 0.0122) 

in the shrub si tes. Although not significant, there were more 

white footed deer mice in the shrub sites both years (59 vs. 

47 captures in 1996, and 26 vs. 11 in 1997). 

At Green Mountain, fewer white footed deer mice (P = 

0.0086), more Great Basin pocket mice (P = 0.0276), and 

fewer yellow pine chipmunks were found in the shrub sites. 

Post-settlement versus Old Growth 

Juniper Woodland 

Five different species were captured in old growth sites 

and three in mid-successional sites in 1997. At old growth 

sites, there were significantly (P = 0.0001) more yellow 

pine chipmunks than in post-settlement woodlands in 1997 

(n = 5 mid, 35 old growth). There were generally more Great 

Basin pocket mice in the mid-successional woodland sites 

which contained a shrub understory (n = 6) than in the old 

growth In = 3). White footed deer mice were about equal 

between the two types (n= 34 and 35 for mid versus old 

respectively). 

Conclusions _________ _ 

Our capture rates were highly variable among sites within 

treatments, among years, and among areas. This undoubtedly caused the lack of significance among many comparisons. With four years of sampling at Page Ranch, we hoped 

to find trends in composition and abundance of small mammals post-cutting. We expected some sampling "noise" but 

not of the magnitude encountered. Sedgwick and Ryder 

(1986) encountered II-fold changes in capture rates among 

years in their pinyon-juniper sampling, and cited several 

USDA Forest Service Proceedings RMRS-P-9. 1999 

others who had documented similar results. We hope to 

periodically sample at least the Page Ranch site to search for 

longer term trends, as those found by Severson (1986) who 

reported total numbers higher in manipulated sites, but a 

variety of individual species responses in New Mexico 18 

years post-treatment. Baker and Frischknect (1973) snaptrapped a chained and seeded pinyon-juniper range, and 

concluded that deer mice and pocket mice populations increased through the second year post-treatment, and then 

dropped to levels still above uncontrolled. This pattern may 

have occurred at Page Ranch, but we couldn't separate 

population patterns from noise. O'Meara and others (1981) 

found higher small mammal abundance (but fewer species) 

in 1,8, and 15 year old chained sites over controls. They also 

pointed out that leaving blocks of unchained vegetation 

within pinyon-juniper control areas should maintain woodland dependent species while providing increased total numbers of small mammals in treated areas. 

The total captures and the number of species captured in 

our study were higher in the cut sites than in the uncut sites, 

comparable to the findings of Sedgwick and Ryder (1986) 

and Severson (1986), although their work was in pinyonjuniper, and the treatments were chainings. 

Although we have no data on optimal size of treatment 

area, our findings concur with others that small openings in 

pinyon-juniper woodlands (Albert and others 1994), and in 

aspen (Populus tremuloides) (Christian and others 1996), 

can benefit a variety of wildlife. Smallwood (1994) expressed 

concern that habitat fragmentation might increase site 

invasibility by exotic birds and mammals through decreased 

indigenous species richness and abundance. In the case of 

fragmenting young and mid-aged western juniper woodlands, our work with small mammals suggests that potential site invasibility by exotics may actually be diminished 

because of increased abundance and richness of indigenous 

species. 

We believe the cut sites, particularly at Page Ranch, had 

preferred structure to the uncut sites which was provided by 

increased vigor (cover and height) of herbaceous species, 

increased seed production in the cut sites (Bates and others 

in press), greater species richness, and juniper slash which 

has persisted five years without noticeable change in size 

and shape. We propose these sites generally provide increased security and forage for small mammals. The lack of 

differences at Krumbo Ridge was probably due to understory 

structure being similar between the two treatments. Woodland conversion had not progressed sufficiently to exclude 

shrubs. Old growth sites typically had a greater variety of 

species than young juniper woodlands. This may be attributable to the more structurally complex vegetation compared to closed post-settlement woodlands (Miller and others, this symposium). 

In our opinion, opening stands of western juniper in 

southeast Oregon by cutting down and leaving trees or 

thinning does not substantially affect the small mammal 

component in the area. The Great Basin pocket mouse 

appears to be the most sensitive species to the loss of shrubs 

during the latter stages of concern from shrub steppe to 

juniper woodland. However, other species such as wood rats 

are favored by the presence of juniper trees in the stand. For 

the maintenance of maximum structural diversity in postsettlement stands, shrub steppe communities should be 

213 
managed through early- to mid-woodland succession (Miller 

and others, this symposium). If conversion crosses a threshold, moving into late and closed woodlands, structural complexity and plant species diversity in the understory decline, 

resulting in shifts in small mammal population dynamics. 

Acknowledgments 

We appreciate the fieldwork ofK. Derby, D. Lancaster, 

T. Miller, G. Popham, and P. Sheeter. Support was provided 

by Burns and Lakeview Districts, BLM; EOARC, Oregon 

State University; The Nature Conservancy; and the Page 

Ranch. 

References __________________ __ 

Albert, S.K, N. Luna, and AL. Chopito. 1994. Deer small mammal, 

and songbird use of thinned Pinon-Juniper plots: preliminary 

results. pp 54-64 in D.W. Shaw, E.F. Aldon, and C. LoSapio eds, 

Desired future conditions for Pinon-Juniper Ecosystems. USDA 

For. Ser. GTR RM-258 

Austin, D. D., and Urness, P. J., 1976. Small mammal densities 

related to understory cover in a Colorado plateau, pinyon-juniper 

forest. Utah Academy of Science, Arts, and letters, 53(1): 5-12. 

Baker, M.F. and N.C. Frischknecht. 1973. Small mammals increase 

on recently cleared and seeded juniper rangeland. J. Range 

Manage. 26: 101-103. 

Bates, J.M., RF. Miller, and T. Svejcar. in press. Understory 

vegetation patterns in western juniper woodlands (Juniperus 

occidentalis ssp. occidentalis). Great Basin Naturalist. 

Christian, D.P., J.M. Hanowski, M. Reuvers-House, G.J. Niemi, 

J.G. Blake, and W.E. Berguson. 1996. Effects of mechanical strip 

thinning of aspen on small mammals and breeding birds in 

northern Minnesota, U.S.A Can. J. For. Res. 26: 1284-1294. 

214 

Fowle, C.D. and RY. Edwards. The utility of break-back traps in 

population studies of small mammals. J. Wildl. Manage. 18: 

503-508. 

Hayward, G.D. and P.H. Hayward. 1995. Relative abundance and 

habitat associations of small mammals in Chamberlain Basin, 

central Idaho. Northwest Science 69: 114-124. 

Johnson, W.C., and B.L. Keller. 1983. An examination of snaptrapping techniques for estimating rodent density in high desert. 

Northwest Science 57(3): 194-204. 

Maser, C., J. W. Thomas, and R G. Anderson. 1984. Wildlife 

habitats in managed rangelands-The Great Basin of Southeast 

Oregon: The relationship of terrestrial vertebrates to plant communities, Part 1, USDA For. Ser. Gen. Tech. Rep. PNW-172. 

25pp. 

Mason, R B., 1981. Response of birds and rodents to controlled 

burning in pinyon-juniper woodlands. M.S. thesis. Univ. Nevada, 

Reno. 55pp. 

McComb, W. C., R G. Anthony, K McGarigal, 1991. Differential 

vulnerability of small mammals and amphibians to two trap 

types and two trap baits in Pacific Northwest Forests. Northwest 

Science 65(3): 109-115. 

O'Meara, T.E., J.B. Haufler, L.H. Stelter, and J.G. Nagy. 1981. 

Nongame wildlife responses to chaining of pinyon-juniper woodlands. J. Wildl. Manage. 45: 381-389. 

Puchy, C. A and D. B. Marshall. 1993. Oregon wildlife diversity 

plan. Oregon Department Fish and Wildlife, Portland, Oregon. 

413pp. 

Sedgwick, J.A and RA Ryder. 1986. Effects of chaining pinyonjuniper on nongame wildlife. pp 541-551 in Everett, RL. compiler, Proceedings-Pinyon-juniper conference; USDA For. Ser. 

Intermountain Research Station Gen. Tech. Rep INT-215. 

581pp. 

Severson, KE., 1986. Small mammals in modified pinyon-juniper 

woodlands, New Mexico. J. Range Manage. 39:31-34. 

Smallwood, KS. 1994. Site invasibility by exotic birds and mammals. Biological Conservation 69: 251-259. 

Turkowski, F.J., and H.G. Reynolds, 1970. Response of some rodent 

populations to pinyon-juniper reductions on the Kaibab Plateau, 

Arizona. Southwest Naturalist 15: 23-27. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Commercial Fuelwood Harvesting Affects on 

Small Mammal Habitats in Central Arizona 

William H. Kruse 

Abstract-In a central Arizona fuelwood harvest area, 75 percent 

of the overstory was cut in a commercial harvest, resulting in large 

quantities of residual logging debris that altered habitat for many 

wildlife species. Small mammals have intricate roles in ecosystem 

function, and current fuelwood management practices have paradoxical affects on small mammal habitats. In a small mammal 

study, no differences in total animals capt,ured were detected among 

treatment plots. Immediately following overs tory reduction or removal in 1992 and 1993, differences among species ca ptures, s pecifically deer mouse, increased significantly. The increased capture 

rate remained significant throughout the remainder of the study. 

Pinyon mouse captures declined significantly immediately following treatments, but were not detectablydifferent from pretreatment 

levels a year later. 

Commercial fuelwood harvesting generates greater and 

more concentrated slash and has more affect on microsite 

conditions than noncommercial fuelwood cutting. This has 

prompted some central Arizona USDA Forest Service Ranger 

Districts to assess the effects of commercial fuelwood removal and slash disposal, particularly by burning. Specifically, removal of slash habitat through burning is a concern. 

Fortunately, commercial harvest permits, however, can provide detailed slash management directions to meet specific 

management objectives. Burning is usually not performed 

by the fuelwood permit holder but instead is included in 

Forest Service management plans. 

Fuelwood removal and slash management also affects 

microsite nutrient cycling, miderstory production (specifically protecting forages from large ungulate grazing), and 

regeneration of overstory species. Small mammal populations are also affected by removal of overstory, understory 

composition and structure change, and slash accumulation 

and subsequent manipulation. Basic ecological information 

is needed to support current harvesting plans (Gottfried 

1987). The least understood management option has been 

slash disposition (Severson 1986, Baker and Frischknecht 

1973). 

Retention or removal of slash provides or eliminates 

specific habitat characteristics for certain small mammals. 

In addition, retention or removal of slash affects the potential protective cover for emerging new plants. Slash removal 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

William H. Kruse is Range Scientist (retired) USDA Forest Service, 

Rocky Mountain Research Station. The Southwest Forest Sciences Complex, 

2500 S. Pine Knoll Dr. Flagstaff, AZ 86001. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

by burning affects the newly formed slash habitat for small 

mammals and plants and also reorganizes the nutrient base 

stored in the slash (Harrington 1989, Covington and DeBano 

1988). Natural decomposition of residual slash provides a 

slower and more complete return of nutrients to the system, 

while providing the protective effects of slash. J uni per slash, 

unlike pine slash, decomposes at a slower rate. 

Small mammal populations are impacted by overstory 

disturbances (Turkowski and Reynolds 1970) while on-theground slash causes an increase in abundance of some 

rodent species regardless of overstory condition (Severson 

1986). Kruse and others (1979) found that when the overstory was removed or reduced, rodents that preferred the 

woodland condition were fewer in number than those on the 

treated areas. 

This small mammal research was part of an effort to study 

the effect of nutrient cycling, other wildlife, and wood product management on soil, water, tree, and range resources in 

pinyon-juniper woodlands. This paper discusses the effects 

of commercial fuelwood harvesting in an old-growth or late 

seral pinyon-juniper woodland on small mammal populations in central Arizona. 

Study Area ________ _ 

The Heber Ranger District, Apache-Sitgreaves National 

Forest in central Arizona was the study-site area. Average 

tree basal area (diameter measured at root crown) was 

23.2 ± 5.4 m2/ha, which produced 35.3 ± 12.7 m3/ha of fuelwood (Kruse and Perry 1995). One-seed juniper (Juniperus 

monosperma) was the dominant species (54 percent). The 

second most dominant tree (25 percent) was Colorado pinyon (Pinus edulis), followed by alligator j uni per (J. deppeana) 

(13 percent). Ponderosa pine (Pinus ponderosa) occasionally 

occurred on moist sites (8 percent). Mean pretreatment 

canopy cover was approximately 40 percent, while the mean 

annual herbaceous and woody plant potential productivity 

was approximately 562 kg/ha. 

The study area is relatively flat, dissected by several small 

ephemeral drainages. Elevations are between 2,000 and 

2,060 m. The primary soil subgroups, derived from limestone, are Lithic Ustochrepts, Udic Haplustalfs, and Typic 

Eutroboralfs. The mean annual precipitation is between 

34 and 46 cm. 

Methods 

Field Methods 

The study area consisted of 33 units, 4 ha in size. Three 

units were treated with silvicultural prescriptions. Thirty 

4 ha study units were grouped into five blocks representing 

215 
Figure 1-Typical overstory, preharvest conditions of 

late seral old-growth pinyon-juniper woodland at Heber/ 

Mud Tank small mammal study area. 

six overstory/slash treatments. Sixteen of the 30 were randomly selected for the small mammal study. Four of the 

6 overstory/slash treatments were replicated in the 16 units 

(Kruse 1995). 

Trapping occurred on 4 overstory treatments: (1) controls, 

where the units were untreated (fig. 1); (2) burned, to 

simulate a forest fire (fig. 2); (3) type conversion, where 

fuelwood was harvested, the non-commercial residual trees 

cut, but slash was not burned (fig. 3); (4) type conversion, 

where fuelwood was harvested, residual trees cut, and slash 

burned (fig. 4). Type conversion is clearcutting to convert a 

woodland to grassland. The two overstory treatments not 

216 

Figure 2-Burned standing green 

woodland to simulated wildfire for 

type conversion (clearcutting to 

convert a woodland to grassland). 

Figure 3-Type conversion. Slash accumulation but 

not burned following harvest of commercial fuelwood. 

Noncommercial stems cut and also remain. 

included were the silvicultural treatments and the commercial harvest where the noncommercial stems were left uncut 

as advanced regeneration. Small mammal trapping was 

conducted during July and August from 1990 through 

1996. Before harvest, downed woody fuel was estimated at 

3.15 mtJha (Kruse and Perry 1995). Post harvest slash 

accumulation was estimated at 55.71 mtlha (fig. 3). 

Treatments were assigned randomly and were not necessarily contiguous; roads or drainage channels could separate 

units within a given block. Harvesting began during fall! 

winter of 1991 and continued for 24 months. Burning commenced when the slash was at least 2 years old. Treatment 

schedules are in Kruse (1995). 

A 100 m2 trapping grid was located in the center of 

each unit. 8 x 10 x 25 cm Sherman live trap was placed at 

each grid point, 10 m x 10 m apart. At alternate points, a 

10 x 12 x 40 cm Sherman live trap was placed near the 

smaller one. The bait was a mixture of chicken scratch and 

rolled oats. Each unit was sampled yearly with 150 traps 

for 3 nights and 2 days. Physical measurements were taken 

and recorded for each animal, then they were toe clipped 

Figure 4-Type conversion. All overstory harvested or 

cut, and slash burned. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 1-Species captured and percent of composition. 

Species Common name Composition 

Percent 

Peromyscus truei pinyon mouse 42 

Peromyscus maniculatus common deer mouse 37 

Eutamias dorsalis cliff chipmunk 9 

Neotoma albigula white-throated wood rat 7 

Neotoma mexicana Mexican wood rat 2 

Peromyscus boylei brush mouse 2 

Sylvi/agus auduboni desert cottontail 

Spermophilus variegatus rock squirrel <1 

Neotoma stephensi Stephens wood rat <1 

Dipodomys ordi Ord kangaroo rat <1 

Microtus mexicanus Mexican vole <1 

and released. Recaptures were noted. Relative abundance 

and species composition of small mammals live trapped and 

released on the study area are in table 1. 

Analysis Methods 

Replicated study units among 4 blocks were selected 

randomly as the experimental design layout (Ludwig and 

Reynolds 1988). Blocks were based on similarity of pretreatment overs tory conditions and characteristics. The treatment units included combinations of no burning or cutting, 

burning standing green, cutting and no cutting (fig. 1-4). 

The small mammal study replicated these 4 treatments in 

each of 4 blocks. 

The null hypotheses was that small mammal capture 

rates did not differ among treatments. Capture differences 

80r-------------------------------~ 

_ Untreated 

60 

............... '1iiiiii"'T~~~t~d" ............. '" 

40 

20 

o 

90 91 93 94 95 

90 vs 91 P = 1.0 

mean 90,91 vs. 93 P = < 0.001 

mean 90,91 vs. 94 P = 0.537 

mean 90,91 vs.95 P = 1.0 

mean 90,91 vs. 96 P = 1.0 

Figure 5-There were no differences in captures between unharvested and to-be- harvested units during the 

pre-treatment period (p > .5). Total captures of all species significantly increased immediately following treatment in 1992-1993 (p < .001). but were not detected 

again (p > .5). 

USDA Forest Service Proceedings RMRS-P-9. 1999 

96 

20 

16 

12 

8 

4 

0 90 91 93 94 95 96 

90 vs 91 P = 1.0 

mean 90,91 vs.93 P = < 0.001 

mean 90,91 vs.94 P = < 0.001 

mean 90,91 vs.95 P = < 0.001 

mean 90,91 vs.96 P = 0.004 

Figure 6-The deer mouse captures. Captures were 

significantly increased immediately following treatments 

in 1992-93 (p < .001). and remained higher through the 

remainder of the study (p < .004) while the slash habitat 

was on the ground aging. Some of the units were burned 

before the 95 and 96 trapping periods but it is unclear 

whether the burning impacted the deer mouse captures. 

among treatments were tested by analysis of variance with 

years used as a repeated measure. Significance oftreatment 

effects was assessed based on temporal interaction (pre vs. 

post treatment) in treatment responses. Comparisons among 

treatments, for individual post treatment years were adjusted by Bonferoni correction to maintain Type I error at 

0.05. Tests were performed on total captures, deer mouse 

captures, and pinyon mouse captures only. The 1992 data 

was also omitted from the analyses due to conflicting treatment effects and application. 

Results __________ _ 

Before 1992 harvest treatments, there were no differences 

among the unharvested and the to-be-harvested units for 

total captures (fig. 5). Although year-to-year differences 

occurred, these data demonstrated the homogeneous nature (p = 1.0) of all units in 1990 and 1991. Analysis of post 

treatment responses, however, indicated significant treatment effect (F= 7.17, p < 0.001). Following treatment, a 

significant difference among treatments in 1993 was demonstrated (F = 5.79, SE 5.47, p < 0.001). Total captures treatment effects were not significant for 1994 (p = 0.536), 1995 

(p = 1.0), and 1996 (p = 1.0). 

Deer mouse captures on the harvested and the unharvested units (fig. 6) also showed the similarity among all 

units before treatment (p = 1.0), and the significant difference between treatments in 1993 (p < 0.001). Unlike total captures, differences for deer mouse captures were significant 

for 1994 (p < 0.001), 1995 (p < 0.001), and 1996 (p = 0.004). 

Half of the harvested units were burned in 1995 and 1996. 

Pretreatment tests on pinyon mouse captures among all 

study units were again similar (p = 1.0). Converse to the deer 

217 
mouse, pinyon mouse captures (fig. 7) significantly reflected 

a negative effect following treatment in 1993 (p = 0.052). This 

negative effect for the pinyon mouse between the harvested 

and non-harvested units was not evident in 1994 (p = 0.322) 

but was evident in 1995 (p = 0.017) and 1996 (p = 0.040). The 

1995 and 1996 harvest unit data included some units that 

were burned in 1994 and 1996; 1996 was before sampling. 

Discussion --------------------------------- This study was designed to evaluate fuel wood harvesting 

affects on small mammal capture rates following the harvest 

of old-growth or late-seral pinyon-juniper woodland overstory. The treatments were 1) overstory removal; 2) creation 

of large quantities of slash that was generally lopped and 

scattered, although some piling was _done to allow cutting, 

loading, and hauling, and 3) eventual slash burning. Data 

were insufficient to determine which treatment activity had 

the greater affect on the small mammal capture rates. 

Therefore, the "treatment" units included overstory removal, 

slash deposition, and some were burned. These "treatment" 

units were tested against the uncut units. 

Although not tested, it appeared that: 1) woodrat (Neotoma 

spp.) middens burned; 2) numbers of captures of all species 

may have decreased following burning; and 3) captures of 

brush mice (Peromyscus boylii) appeared to be greater on 

unburned slash units. Initially, both Peromyscus species 

responded positively or negatively to the harvest treatment 

and some differences continued for the following 3 years. 

Half of the harvested units were burned in 1994 and 1995. 

Burning standing green, during a wildfire simulation, occurred in 1994 and 1996. The study suggests that overstory 

removal and slash accumulation probably had more beneficial effects for the deer mouse, specifically, and to other species 

as well. These 2 effects were detrimental to the pinyon 

mouse, however, particularly in the year following cutting. 

This study corroborates earlier work showing that overstory 

is important to the pinyon mouse (Severson 1986). Burning, 

which would not have correctea the lack of overstory condition, was of further detriment to the pinyon mouse. 

Fewer captures of all species were evident in the latter 

3 years that included the burning portion of the study. Tests 

between treated and untreated units suggest little significant difference, while treatment effects to the deer mouse still 

appear beneficial. Field observations suggest that unburned 

units still contained viable woodrat middens and higher 

capture numbers for other species such as the cliff chipmunk 

(Eutamias dorsalis). Baker and Frischknecht (1973) found 

no effect from slash on mice populations, except where it was 

windrowed, while Severson (1986) found that treatments 

leaving slash benefited woodrats and brush mice following 

canopy removal. Therefore, the detrimental burning effects 

in this study could have off-set the beneficial effects of the 

slash. In addition, slash provided improved site protective 

characteristics for plant regeneration and development. 

Population densities of small mammals are related to 

overstory adjustments and/or slash composition in assessing site productivity and quality. This study contributes to 

small mammal and basic ecological information to improve 

guidelines for harvesting fuel wood in pinyon -j uni per ecosystems in the Southwestern United States. 

218 

35 

30 

25 

20 

15 

10 

............... IMJ .. l)n~~~?:t.~9; ...... . 

5 

o 

_ Treated 

90 91 93 94 95 

90 vs 91 P = 1.0 

mean 90,91 vs.93 P = 0.052 

mean 90,91 vs.94 P = 0.322 

96 

mean 90,91 vs.95 P = 0.017 

mean 90,91 vs.96 P = 0.040 

Figure 7-Pinyon mouse captures. Captures were significantly decreased immediately after treatments were 

implemented in 1992-93 (p = .05), but not detectably 

lower a year later (p = .32). Lower captures on the 

treated units were again apparent in 1995-96 (p < .04). 

References _________ _ 

Baker, Maurice F. and Neil C. Frischknecht. 1973. Small mammals 

increase on recently cleared and seeded juniper rangeland. J. 

Range Manage. 26: 101-103. 

Covington, W. Wallace and Leonard F. DeBano. 1988. Effects of fire 

on pinyon-juniper soils. pp 78-85. In Proceedings: Effects of Fire 

in Management of Southwestern Natural Resources. Tucson, 

Arizona. Nov. 14-17, 1988. 

Gottfried, Gerald J. 1987. Regeneration of pinyon. In: Proceedings-pinyon-juniper conference; 1986 January 13-16; Reno, NV. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 249-254. 

Harrington, M.G. 1989. Soil nutrient and pinyon seedling response 

to fire severity, p.143-147. In: Proceedings of the 10th conference 

on fire and forest meteorology, Maciver, D.C., ed. and others 

Chalk River, Ont.: Forestry, Canada, 1989,469 p. 

Kruse, W. H. 1995. Effects offuelwood harvesting on small mammal 

populations in a pinyon-juniper woodland, p91. In; Douglas W. 

Shaw; Earl F. Aldon; Carol LoSapio, tech. Coords. Desired future 

conditions for pinyon-juniper ecosystems; proceedings of the 

symposium; 1994 August 8-12; Flagstaff, Arizona. GTR-RM-258. 

Fort Collins, CO. USDA-For. Serv., Rocky Mtn. For. & Range 

Exp. Stn, 226 p. 

Kruse, W. H. and H. M. Perry, 1995. Ecosystem management and 

fuelwood harvesting in an "old growth" pinyon-juniper woodland, 

p219.In; Douglas W. Shaw; Earl F. Aldon; Carol LoSapio, tech. 

Coords. Desired future conditions for pinyon-juniper ecosystems; 

proceedings of the symposium; 1994 August 8-12; Flagstaff, 

Arizona. GTR-RM-258. Fort Collins, CO. USDA-For. Serv., Rocky 

Mtn. For. & Range Exp. Stn, 226 p. 

Kruse, W. H., R. P. Balda, M. J. Simono, A. M. Macrander, and C. D. 

Johnson. 1979. Community development in two adjacent pinyonjuniper eradication areas twenty-five years after treatment. J. 

Environ. Manage. 8: 237-247. 

Ludwig, John A. and James F. Reynolds. 1988. Statistical ecology. 

New York: John Wiley and Sons. 337 p. 

Severson, K. E. 1986. Small mammals in modified pinyon-juniper 

woodlands, New Mexico. Journal of Range Management. 39: 31-34. 

Turkowski, F. J. and H. G. Reynolds. 1970. Response of some rodent 

populations to pinyon-juniper reductions on the Kiabab Plateau, 

Arizona. Southwest. Natur. 15:23-27. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Dietary Use of Utah Juniper Berries 

by Gray F'ox in Eastern Utah 

Craig G. White 

Jerran T. Flinders 

Rex G. Cates 

Boyde H. Blackwell 

H. Duane Smith 

Abstract-The contents of214 gray fox (Urocyon cinereoargenteus) 

scats from the Nash Wash pinyon (Pinus edulis)-juniper (Juniperus osteosperma) zone of eastern Utah were analyzed. Analyses 

revealed that mature Utah juniper berries were the most commonly taken food items by mean percent relative frequency of 

occurrence (51.1 percent, dry weight) and mean percent of volume 

(51.3 percent, dry weight) for the time period of April 1994-March 

1996. Utah juniper berries dominated the diet for 6 of 8 3-month 

seasonal periods (Spring 1994, Summer 1994, Fall 1994, Winter 

1995, Fall 1995, and Winter 1996). Mammalian prey, mostly 

rodents and leporids, represented the majority of the diet not 

consisting of Utah juniper berries. Chemical analyses of the hulls 

of Utah juniper berries indicated that they provide a basic supply 

of nutrients and minerals. The diets of gray fox in eastern Utah 

showed that they are efficient foragers specializing on an interesting mix of vegetation and animal matter. Decided dietary selection 

was evident, since some available fruits were not found in diets. 

The distribution of gray fox (Urocyon cinereoargenteus) is 

extensive, ranging from extreme southern Canada to northern South America, excl uding eastern Central America, the 

Great Plains, and portions of the northwestern United 

States (Fritzell 1987). Seasonal diets and habitat use of 

gray fox have been studied broadly in the southeastern, 

eastern and north-central United States (Trapp and 

Hallberg 1975; Fritzell 1987). However, there is a paucity 

of research regarding the behavioral ecology of gray fox in 

the pinyon (Pinus edulis)-juniper (Juniperus spp.) zones of 

the western United States. Trapp (1978) compared the 

behavioral ecology of the ringtail (Bassariscus astutus) and 

gray fox in Zion National Park, Utah. Turkowski (1970) 

studied gray fox in the Upper and Lower Sonoran Life zone, 

and Harrison (1997) compared gray fox ecology between 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Craig G. White completed an M.s. in Wildlife and Range Resources, 

Department of Botany and Range Resources, Brigham Young University, 

Provo, UT 84602. Jerran T. Flinders is Professor of Wildlife and Range 

Resources, Department of Botany and Range Resources, Brigham Young 

University, Provo, UT 84601. Rex G. Cates is Professor of Botany, Department of Botany and Range Resources, Brigham Young University, Provo, UT 

84602. Boyde H. Blackwell, Program Coordinator, Utah Division of Wildlife 

Resources, Salt Lake City, UT84116. H. Duane Smith is Director of the Monte 

L. Bean Life Science Museum, Brigham Young University, Provo, UT 84602. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

residential and undeveloped rural landscapes in New 

Mexico. In addition, Small (1971) tried to determine the 

interspecific competition for food among coyotes (Canis 

latrans), gray foxes, and bobcats (Felis rufus) on a ranch in 

Arizona. 

In 1993, our study was undertaken to investigate behavioral ecology of the gray fox. In order to determine the 

degree, and season, of dependence of gray fox on various 

prey (that is, leporids, rodents, and juniper berries), the 

study included evaluation of its diet using scat analyses. 

Study Area 

The study site chosen was the Nash Wash Wildlife Management Area (NWMA) (39°4' N. 109°35'30" W.) and surrounding area in Grand County, Utah. The Nash Wash 

drainage and its ephemeral streams appeared to provide 

suitable habitat for gray fox. The habitat included pinyonjuniper (Juniperus osteosperma), mixed mountain brush, 

big sagebrush (Artemisia tridentata), desert saltbush and 

associated riparian zones intermixed with numerous cliffs 

and rocky outcroppings. 

Elevation ofthe study area ranges from 1,500 to 2,250 m. 

The range of elevation and topography results in several 

microclimates with variable precipitation and temperatures. Weather data from a Bureau of Land Management 

(BLM) Resource Automatic Weather Station (RAWS) located at 39°07'30" N. 109°42'20" W. (elevation 2,438 m) 

shows the average annual precipitation per year during the 

study was 201 mm. Daily high and low temperatures 

ranged from 2 to -6°C in January and 28 to 16°C in July. 

Objectives 

Preliminary analyses of 24 gray fox scats taken in the 

study area led to the development ofthe following research 

hypotheses concerning gray fox diets. 

1. Diets of gray fox can be accurately and quantitatively 

assessed through identification of plant and animal residue 

in scat. 

2. Animal matter would be preferentially chosen over 

plant material during the reproductive periods of gray fox, 

rodents, leporids, and insects. 

3. Juniper berries and fruits of other woody plants in the 

study area are only seasonal augmentations, rather than 

important nutritional components, of gray fox diets. 

219 
4. Hulls of mature juniper berries are chemically complex but not nutritionally adequate to serve as a primary 

source of nutrition for the gray fox. 

Methods 

Diet Analysis 

Gray fox scat was collected along scat deposition transects 

conducted by White and others (1997). Collection of scat 

also occurred along dry stream beds, ridges, overhangs, and 

sagebrush-grass flats. To insure that only gray fox scat was 

collected, the guidelines by Green and Flinders (1981) and 

Halfpenny and Biesiot (1986) were followed along with 

knowledge of species specific locations and use of habitat. If 

a scat could not be identified with confidence, it was not 

used in the analysis. Date, location, and other pertinent 

information including estimated age of each scat sample 

were recorded. 

In the laboratory, diameter in millimeters at the largest 

width was recorded for each air dried scat with a caliper. 

Dry weight of each scat was recorded in grams. All scats 

were then "heated" in a drying oven at 60-70 °C for 24 hours 

to kill any microorganisms. Subsequently, each scat was 

placed in a fine mesh nylon bag (42 meshes per cm), soaked 

in water and laundry detergent, and then washed in a 

conventional washing machine to remove mucus, metabolites and dissolvable organic matter (O'Neal and others 

1987; Findlay 1992). Each scat was then spread evenly on 

a tray, 25 x 25 cm, with a grid having 25 random points 

assigned. Contents of scat were identified using two methods. O'Neal and others (1987) and Findlay's (1992) procedures for determining percent frequency of occurrence and 

relative percent frequency of occurrence were followed with 

minor modifications. 

To facilitate food item identification, a dissecting microscope (0.7-3 power zoom) was used with published keys for 

identification of hair (Adorjan.and Kolenosky 1969; Moore 

and others 1974). A "mammal hair" collection was used as 

well as mammal, entomology, and herbarium collections at 

the Monte L. Bean Life Science Museum, Brigham Young 

University, to identify food items. The Martin and Barkley 

(1961) seed identification manual was used for seed identification. Taxonomic nomenclature was standardized using 

the following authorities: Wilson and Reeder (1993) (mammals), Welsh and others (1993) (flora), Robbins and others 

(1983) (birds), Borror and White (1970) (arthropods), and 

Stebbins (1985) (reptiles and amphibians). 

Relative Percent Frequency of Occurrence 

(RPFO)-In order to determine the relative percent frequency of occurrence it was first necessary to determine the 

frequency of occurrence. This was done by sampling 25 

random points within the 25 x 25 cm tray and noting the 

nearest identifiable food item. The number of occurrences 

for each identifiable food item was divided by the total 

number of points sampled (25) and multiplied by 100 to give 

percent frequency of occurrence for each identified food 

item in each scat. 

When identifying food items, an effort was made to 

identify each item to genus and species if possible or to the 

next higher taxonomic level possible. If several identifiable 

220 

food items were located on the same point (for example, 

mammalian hair and Juniper berry), then one point was 

assigned to each food item, making it possible to have a dot 

count total exceeding 25. The relative percent frequency of 

occurrence was determined for each scat by summing the 

percent frequency of occurrence values for all identified 

food items and dividing each individual value by the sum of 

frequency value. 

Relative Percent of Volume (RPV)-All identifiable 

food items were ocularly estimated as percent of volume 

(PV) for each scat. Food items identified and assigned a PV 

value were summed and divided by the summation of PV 

values to obtain a RPV. 

For this report, prey items were classified into seven 

major categories: Mammals, Birds, Arthropods, Reptiles 

and Amphibians (Rep. & Amph.), Utah Juniper Berries, 

Miscellaneous Vegetation (Misc. Vegetation) (that is, grass, 

woody vegetation and their seeds), and Miscellaneous Items 

(Misc. Items) (that is, rocks, sand, finite vegetation mixed 

with sand, unknown items). A Spearman's Rank Correlation test was used to evaluate similarity of RPFO and RPV 

values for each major temporal category. Additionally, a 

Kruskal-Wallis Test was applied to test for significance of 

differences among years or seasons for each major food 

category. After determining ifthere were significant differences among groups of factors, individual factors were 

tested for significance against each other using Gibbons' 

(1976) method. All percent data were arcsine transformed 

before statistical analyses. 

Leporid and Rodent Availability 

To determine ifleporids and/or rodents in the diet of gray 

fox was correlated with leporid and/or rodent availability in 

their habitat, leporids and rodents were assessed along 

three permanent census transects established by White 

and others (1997) in NWMA. Each transect, 3.2 km 

(2 miles) long, was established along an existing dirt road. 

Scat deposition transects, operated by White and others 

(1997), were also located on these transects. Thus, the 

census transects for leporids and rodents traversed roads 

where most of the gray fox scat analyzed in our study was 

collected. Transects names listed here and locations were 

the same as White and others (1997) transects, with the 

exception that our Transect C corresponded to their Transect 

E. Transect's names and periods of study are: 

• Transect A-July 1993 to December 1996 

• Transect B-March 1994 to December 1996 

• Transect C-July 1993 to November 1993; May 1995 to 

December 1996 

Correlation tests comparing leporids and rodents in the 

diet of gray fox and leporids and rodents availability were 

based on the Spearman's Rank Correlation procedure. 

Kruskal-Wallis Tests were used to eval ua te significances of 

differences among years or seasons of rodent and leporid 

use by gray fox. After determining if there were significant 

differences among a group of factors, individual factors 

were tested for significance against each other (Gibbons 

1976). All percent data were arcsine transformed before 

statistical analyses. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Rodent Assessment-To obtain a relative estimate of 

rodent numbers along the three transects, scent stations by 

White and others (1997) for gray fox monitoring were also 

evaluated for rodent use. Although the scent stations were 

designed for census of gray fox, the consistency of the 

method provided a relative measure of rodent abundance 

as well. 

Scent station methodology followed the procedures recommended by Whi te and others (1997). Along each transect, 

101.0 m2 track stations (metal sheets) were placed 5 to 20 m 

perpendicular to the road. Each station was placed 0.3 km 

(0.2 miles) apart. The afternoon before the census was 

conducted, metal sheets were blackened with burnt acetylene from a welding torch. In the center of the sheet was 

placed a 1 inch diameter Scented Predator Survey Disk 

(SPSD) made of plaster of Paris. SPSDs were previously 

soaked in Fatty Acid Scent (FAS) which acts as an attractant (Roughton and Sweeny 1982). The scent stations were 

examined the following morning. Visits to stations are 

recorded by species and a species visit to a station is 

recorded as 1 no matter how many tracks ofthat species are 

left on the soot covered metal sheet. Since it was easy to 

identify a track as that of a rodent but difficult to identify 

the species of rodent, a visit was defined as ,?1 track of a 

rodent per station, regardless of the number of rodent 

tracks on a station. The index of abundance has normally 

been expressed as the number of stations visited by a 

species divided by the number of operable stations sampled 

that night times 1000 (Linhart and Knowlton 1975; Lindzey 

and others 1977; U.S.F.W.8. 1984). 

___ 1'<_o_ta_I_S.:....p_e_cl_·e_s_V;_l_·s_it_s ___ * 1000 = Index Value 

Total Operable Stations 

"Total Species Visits" in this formula would then be equivalent to the total number of stations visited by rodents. 

The sheets were re-blackened before each census and 

SPSDs re-saturated. Scent stations were operated only one 

night per month for the majority ofthe diet analysis period. 

Only da ta from Transect A and B were available for the first 

year of the diet analysis study. 

Leporid Assessment-Availability of leporids was assessed by two methods. Spotlight transects were conducted 

each month along the three operating transects. The procedure, modified from the King method (Hayne 1949), was to 

have an observer stand in the back of a pickup truck (or 

from the cab if only one researcher was available) with a 

spotlight (1,000,000 candle power) while traversing each of 

the 3.2 km (2 mile) transects. All mammals observed were 

recorded by species and their perpendicular distance from 

the road was estimated. Binoculars (10 x 50) were often 

used to assist in identification of species. Only data from 

Transect A and B were available for the first year ofthe diet 

analysis study. 

The second method involved counts of leporid fecal pellets in plots located along the three transects used in our 

study. For each transect, 10 circular plots (each 10 m2)were 

established. They were located 0.32 km (0.20 miles) apart 

with 4 (0.45 m2 each) leporid fecal pellet plots placed within 

each 10 m2 circular plots. Location of the fecal pellet plots 

within the circular plot involved placing one leporid fecal 

plot at the inside edge of each of the circular plot's cardinal 

USDA Forest Service Proceedings RMRS-P-9. 1999 

directions. The three transects combined had a total of 120 

leporid fecal pellet plots. 

Plots were monitored in the spring (May-June) and near 

the end of summer (August) seasons. All new pellets were 

counted and cleared at the end of each of these periods 

(Flinders and Crawford 1977). To ensure accuracy, colored 

nails were placed in two opposite corners of each 0.45 m2 

plot and the UTM coordinates of each 10 m2 circular plot 

were obtained using a Magellan 5000 Pro global posi tioning 

(GPS) unit. To account for degradation due to weather and 

invertebrates Blackwell's (1991) pellet degradation rate 

was used to estimate loss of pellets over time. Leporid 

abundance was estimated along all transects for summer 

and fall-winter seasons of 1994, 1995, and 1996. Leporid 

abundance was calculated using Cochran and Stains (1961) 

estimated number of fecal pellets voided per cottontail per 

day. 

Nutritional and Chemical Analyses of Utah 

Juniper Berries 

Preliminary analyses showed large numbers of mature 

Utah juniper berries in gray fox scat. Literature could not 

adequately answer whether juniper berries constituted a 

satisfactory or starvation diet. Thus, Utah juniper berries 

were collected monthly from June 1995 to October 1996. 

Mature berries were identified from immature berries 

using the criteria of Johnsen and Alexander (1974) as cited 

in Young and Young (1992). Collection and analysis of 

immature and mature berries occurred separately. A group 

of 4-5 trees were sampled each month with an additional 3-

7 trees being sampled as needed. All mature berries collected in a month were placed in one bag, thus making one 

bulk sample of matures berries per month, for analysis. 

Immature berries were also collected in one bulk sample 

per month. Berries were weighed in the field after collection 

and then weighed again in the laboratory after being dried 

in an oven at 60-70 °C for several days. Fleshy tissue (hull) 

for each was removed from around the seed and hulls were 

ground in a Wiley Mill (20 mesh screen) for dry juniper 

berry analyses. Mineral and nutritional analyses of dry 

Utah juniper berry hulls were conducted by the Soil and 

Plant Analyses Laboratory at Brigham Young University 

(BYU) (Provo, Utah) using the methods outlined by Horwitz 

(1980). Although analysis occurred on one bulk sample of 

mature berries per month, it should be noted that bulk 

samples were comprised of berries from several different 

trees. Immatures were also analyzed as one bulk sample 

per month and a sample was comprised of berries from 

several trees. 

From October 1995 to October 1996 a portion of the 

monthly Utah juniper berries collected, by the procedure 

described above, were weighed in the field and immediately 

frozen. The berries were transported to the lab in a cooler. 

At the lab, berries were kept in a freezer for "wet" chemical 

analyses. Before wet chemical analyses, berries were removed from the freezer and approximately 10 g of fleshy 

tissue (hull) was separated from the seeds, ground with 

mortar and pestle in liquid nitrogen, and put back in the 

freezer within a few minutes. Further fractional analyses of 

chemicals in wet and dry juniper hulls were undertaken by 

the Plant Product Chemistry Laboratory also at BYU. 

221 
Their extraction of tannins, phenolics, and terpenes followed the procedures of Zou and Cates (1995). Gross energy 

(kcal) content of dry mature Utah juniper hulls was determined using a Parr Adiabatic Oxygen Bomb Calorimeter 

(Model 1241). 

A Wilcoxon Sum Rank Test was used to test for significance of differences between the minerals, nutrients, and 

chemical components of mature and immature Utah juniper hulls. All percent data were arcsine transformed before 

statistical analyses. 

Results and Discussion 

Diet Analyses 

It was common to find gray fox scat on small rocks, 

boulders, logs next to the roads, on the roads, and next to 

older feces of gray fox or other species. A sample of214 gray 

fox scats (deposited from April 1994 to March 1996) was 

selected for dietary analysis. These scats had a mean diameter of 14.9 mm (SD = 1.6 mm, n = 179) with a range from 

10 to 18 mm. The mean air dry weight was 7.5 g (SD = 3.5 g, 

n = 213) with a range from 0.9-25.7 g. The mean diameter was 

within 0.3 mm of Trapp's (1978) findings (x = 15.19 mm, 

SD = 2.50 mm, range = 9-24 mm) at Zion National Park. 

A total of 25 mammalian and 1 avian food items were 

identified to genus. Of the mammalian food items, Sylvilagus 

(cottontail) had the highest RPFO and RPV values. 

Peromyscus (white-footed mice) had the second highest 

RPFO and RPV values. Three Classes (with 13 Families 

representing 12 Orders) of Arthropoda were recognized. 

The group having the highest percent RPFO and RPV was 

the Gryllacrididae (camel crickets and others). All fox scat 

that contained Gryllacrididae, except one, could be seen to 

contain the subfamily Stenopelmatine (Jerusalem crickets). Both suborders of reptiles (snakes and lizards) were 

represented. Since some food items could only be identified 

as either reptile or amphibian these categories were lumped 

together. Thirteen different genera offorbs, shrubs, or trees 

were represented in the diet of gray fox. Twelve different 

genera (including Utah juniper berries) of forb, shrub, or 

tree seeds (or flowering parts) were identified. Miscellaneous items were discovered but the most consistent was 

sand-size rock and minerals. Likely some of the Miscellaneous Vegetation and most of the Miscellaneous I terns were 

inadvertently ingested while consuming other food items. 

To visualize the annual diet these foregoing data were 

organized by season of use defined as follows: April-June 

(Spring), July-September (Summer), October-December 

(Fall), January-March (Winter). These seasons appeared to 

coincide best with shifts in diet as well as changes in 

meteorological seasons and vegetational phenophases. A 

total of eight seasons (figs. 1-5) were analyzed by RPFO and 

RPV methods using major prey categories. The mammalian 

prey items of importance are shown beneath the major prey 

categories in figures 1-5 and are grouped into three subcategories: Rodents, Leporids, and Other (that is, carrion and 

all other mammalian prey). The RPFO and RPV methods 

suggest similar amounts of the various dietary categories 

in all seasons. Thus discussion in the text will be applicable 

to both methods unless otherwise specified. 

222 

Spring 1994 and 1995-Gray fox relied more heavily on 

Utahjuniper berries than mammalian prey in the Spring of 

1994, however in the Spring of 1995 they relied more 

heavily on mammalian prey (fig. 1). Individual prey in the 

mammals category also switched from leporids being highest in the Spring of 1994 to a higher rodent content in the 

Springofl995. Arthropods accounted for approximately 10 

percent of the diet and were the third largest category in the 

Spring of 1994 but accounted for less than 3 percent in the 

Spring of 1995 and were only the fifth largest category. 

Summer 1994 and 1995-The diets of gray fox during 

these summers shifted from being more dependent on Utah 

juniper berries in 1994 to being more dependent on mammalian food in 1995 (fig. 2). Utah juniper berries and 

mammalian prey maintained the top two positions for 

dietary items in both years. Mammalian prey showed 

leporids and rodents were fairly even the first summer, but 

rodents were taken in greater amounts than leporids in 

1995. Arthropods accounted for approximately 10 percent 

ofthe diet: they were the third highest item by either RPFO 

or RPV values. Misc. Vegetation contributed measurably to 

gray fox diets in both summer periods. 

Fall 1994 and 1995-During both fall periods, Utah 

juniper berries constituted the major portion of gray fox 

diets (fig. 3 ). Leporids accounted for a lesser percent than 

did rodents in 1994 with the reverse being true in 1995. 

Diets during both fall periods consisted of little other than 

Utah juniper berries and mammals. 

Winter 1995 and 1996-During both winters, Utah 

juniper berries dominated the diets of gray fox (fig. 4). 

Mammalian prey contributed almost twice as much in 1996 

as in 1995. Leporids contributed slightly more to the mammalian prey take than did rodents in 1995 but were slightly 

less or equal to rodents in 1996. The mammalian prey 

category "Other" was higher in 1996 than in 1995 and was 

comprised largely of carrion (that is, deer and per or elk 

hair). Misc. Vegetation and Misc. Items contributed more 

to gray fox diets in 1996 thanin 1995. 

April 1994 to March 1996-0verall, Utah juniper berries contributed 50 percent or more to diets of gray fox 

during the two years scat was collected (fig. 5). Mammals 

were the next common prey item contributing just over 35 

percent. Rodents were the most common mammalian prey, 

followed by Leporids, and then "Other" mammals. The 

third highest category was Misc. Vegetation, fourth was 

Misc. Items, and then Arthropods, Rep. & Amph., and 

finally Birds. 

By comparison, Turkowski (1970) found that mammals by percent occurrence, overall, contributed more to 

gray fox diet than other items in the southwestern United 

States. He noted rodents were the primary mammalian 

prey, while plants (principally grasses and legumes) 

contributed the next greatest percent. Trani (1980) found 

that along the northern California coast gray fox existed 

primarily on an herbaceous diet. True fleshy fruits, by 

percent volume and percent frequency, were major foods. 

Mammals were the next most important prey selected in 

Trani's study and rodents as a group were the most 

important mammal prey. In Trapp's (1978) study of gray 

fox at Zion National Park, juniper berries and berry 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Spring 1994 I~RPFO .RPvl 50r-------~========~------~ 

40 

C 30 Q) 

~ Q) 

a.. 20 

RPFO RPV 

eROdents Rodents 

12.0% _14.7% 

Leporids Other Leporids Other 

18.7% 4.4% 18.3% 3.5% 

Mammals in Diet by Percent 

Spring 1995 

I ~RPFO .RPV I 80r-----~========~----~ 

60 

c 

Q) 

~ 40 a.. 

20 

RPFO RPV 

ROdents. ROdents. 39.6% 36.7% 

Leporlds Leporids 

33.7% 31.0% 

Mammals in Diet by Percent 

Figure 1-The 7 major diet categories of Spring (July-June) 1994 and 1995 

seasons are depicted here by the RPFO and RPV values. The mammalian 

prey items of importance are shown beneath the major prey categories and 

summed to equal the percent shown in the Mammals category. 

Summer 1994 Summer 1995 

60 I~RPFO .RPV I I~RPFO .RPvl 

60 

50 50 

40 40 

C C Q) 30 Q) 

~ t.l 30 Q) Qj a.. a.. 20 20 

10 10 

0 0 ({y~ o~ b~ '$:-' • 0(' . 'O~ f$'~ ({y~ 

f$'~ <~l QO ~~ r'§i' ~<.." ~0 ~ &0 ~ W <Q'O v:' ~Ilf ~flJ.~ "?-~ ~ ~'OCf> .!lJ<" ~Cj «:-0~ v' ~-q ~Cj '$:-')":> 

-.0 ...... Ilf 

RPFO RPV RPFO RPV 

Rodents Rodents 

8 3.6% .1.8% 

Leporids _ Other L~~~~S Other 

13.4% 4.0%' 0 5.7% 

R d t .Other ROdents.Other 3~.~~os 2.3%. 26.8% 2.0% 

Leponds Leporids 

17.8% 18.0% 

Mammals in Diet by Percent Mammals in Diet by Percent 

Figure 2-Shown here are the RPFO and RPV values of the 7 major diet 

categories for Summer (July-September) 1994 and 1995 seasons. The 

mammalian prey items of importance are shown beneath the major prey 

categories and summed to equal the percent shown in the Mammals 

category. 

USDA Forest Service Proceedings RMRS-P-9. 1999 223 
224 

Fall 1994 Fall 1995 

100 I~RPFO .RPvl IB:lRPFO .RPvl 

70~------~========~----~ 

60 

80 

50 

C 60 Q) 

u 

Q; 

a.. 40 

C 40 

~ cf. 30 

20 

20 

10 

0 

!itt:;, ~ 

~~~ 

RPFO RPV RPFO RPV 

Rodents 

•

. 1% 

Other 

Leporids 1.3% 

8.2% • 

Rodents 

Leporids 3.5% 

9.0% 

Other 

1.8% 

LepOridft LepOridse 11.5% 9.9% 

other Rodents Other Rodents 

2.8% 18.8% 1.3%- 14.5% 

Mammals in Diet by Percent Mammals in Diet by Percent 

Figure 3-Depicted here are the RPFO and RPV values of the seven major 

diet categories for Fall (October-December) 1994 and 1995 seasons. The 

mammalian prey items of importance are shown beneath the major prey 

categories and summed to equal the percent shown in the Mammals category. 

Winter 1995 Winter 1996 I~RPFO .RPvl 100~----~==========~-----' 

IB:lRPFO .RPV I 

60~------==========~-----' 

80 50 

40 

C 60 Q) 

~ 

cf. 40 

~ ~ 30 Q) 

a.. 20 

RPFO RPV RPFO RPV 

R~~'!2ts 

Other 

Leporids 2.7% 

12.2% 

Rodents 

•

. 5% 

. Other 

Leponds 240A 

10.2% . 0 

Rodents Rodents 

•

. 7% .2.2% 

Leporids 

Leporids Other 12.2% Other 

10.9% 7.7% 9.0% 

Mammals in Diet by Percent Mammals in Diet by Percent 

Figure 4-The 7 major diet categories of Winter (January-March) 1995 and 

1996 seasons are shown here by the RPFO and RPV values. The mammalian 

prey items of importance are shown beneath the major prey categories and 

summed to equal the percent shown in the Mammals category. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
April 1 994 - March 1996 

I&83RPFO .RPvl 60~-----===========~----~ 

50 

40 

'E 

~ 30 Q) 

RPFO RPV 

a. 

20 

Leporids Leporids 

15.0%_ 14.6%_ 

Other Rodents Other Rodents 

3.3% 18.4% 3.4% 15.9% 

10 

Mammals in Diet by Percent 

Figure 5-Shown here are the RPFO and RPV values of the seven major 

diet categories from April 1994 to March 1996. The mammalian prey items 

of importance are shown beneath the major prey categories and summed 

to equal the percent shown in the Mammals category. 

pricklypear (Opuntia phaeacanatha) fruits contributed 

the highest frequency and the greatest volume. Mammalian prey, mainly carrion, contributed the second largest 

frequency value, while arthropods were the second highest 

group by percent volume. All three researchers noted seasonal shifts in the diet of gray fox. Seasonal periods were 

different in all three studies and the main prey items varied 

somewhat for the various seasons. Small's (1971) study in 

Arizona analyzed scats collected over five months (March to 

July) and reportedjuniper berries to be the most frequently 

observed food taken by coyote (79.7 percent) and gray fox 

(87.0 percent). The next most common prey item by frequency of occurrence for gray fox was invertebrates. 

Our study indicated that mature Juniper berries maintained the largest RPFO and RPV values in 6 of the 8 

seasons monitored. Mammals were the commonest prey 

item by RPFO and RPV during Spring 1995 and Summer 

1996. A monthly comparison can be made for 22 of the 24 

months. By RPFO, mammalian prey had the highest frequency in 7 ofthe 22 months. Using RPV, mammals had the 

highest volume in 8 of the 22 months. Utah juniper berries 

dominated in all other months by both methods. Leporids 

made up the greatest percent of the mammalian prey by 

RPFO and RPV during the first year, whereas Rodents 

contributed a greater percent to the Mammals category the 

second year. 

A major difference between Trapp's Zion National Park 

study and our own was the percent frequency of arthropods 

(57 percent) compared to our RPFO of 2.5 percent. Trapp 

also reported an annual use of berry pricklypear fruit 

(30 percent) as well as several other types of fruits which 

did not occur in any of the fox scat that we examined from 

USDA Forest Service Proceedings RMRS-P-9. 1999 

NWMA. This is not surprising since Welsh and others 

(1987) did not place berry pricklypear, and several of the 

plants occurring in Trapp's study area, as far north as the 

NWMA. 

Fruits of several plant genera are known to occur in diets 

of black bear (Ursus americanus), coyote, red fox (Vulpes 

vulpes) and/or gray fox (Trapp and Hallberg 1975; Turkowski 

1970; Wilson 1993). These plant genera include skunkbush 

or sumac (Rhus), elderberry (Sambucus), snowberry (Symphoricarpos), acorns (Quercus), serviceberry (Amelanchier), 

rose (Rosa) as well as several cultivated fruit trees. Surprisingly, species from several of these genera were present in 

NWMA but their fruits and/or seeds were not identified in 

the gray fox diet. The plant genera and species included 

skunkbush (Rhus aromatica), blue elderberry (Sambucus 

caerulea), snowberry (Symphoricarpos spp.), Gambel oak 

(Quercus gambelii), serviceberry (Amelanchier alnifolia), 

woods rose (Rosa woodsii), and some cultivated fruit trees. 

In addition, nuts of pinyon pine are seasonally quite abundant and widespread but were never observed in diets of 

gray fox studied. Cultivated fruit trees in the area were 

located at the Cunningham Ranch in the southern portion 

of the study area. The Ranch had a caretaker and a dog on 

the premises since the spring of 1994. The activity in the 

area possibly deterred gray fox use of these fruit trees. 

Food selection by gray fox in eastern Utah did not follow 

the generally held beliefthat they are opportunistic feeders 

exploiting a wide range of seasonally available dietary 

items. Gray fox in the NWMA specialized on an interesting 

mix of vegetation and animal matter while avoiding some 

foods such as pinyon nuts, acorns, skunkbush. Sterotypic 

225 
diet preference is shown by the avoidance of other available 

berries. 

Statistical Analyses of Diet-A Spearman's Rank Correlation revealed significant correlation (p-value = 0.05) 

between, RPFO and RPV values, for the seven major food 

item categories except Rep. & Amph. (rg = 0.63, P = 0.09). 

The Utah Juniper Berries category had a perfect correlation at rg = 1.00 (P = 0.00) for the 2 indicator values. The 

three subcategories of Mammals (Rodents, Leporids, and 

Other) also showed significant correlation between RPFO 

and RPV. This indicates that both indicators, RPFO and 

RPV, predict similar use offood items by gray fox. Although 

it was noticeable that RPFO, which relies on a food item 

falling on one ofthe 25 randomly placed dots, did not always 

account for all food items found in a scat, it is not significantly different from RPV which does account for all food 

items found in a scat. 

A statistically significant correlation was apparent across 

the eight seasonal periods for 4 of the 7 major food item 

categories by RPV and 3 of the 7 by RPFO. Gray fox, by 

RPFO and RPV, consumed significantly more Mammals 

(H = 47.61, P = 0.00 and H = 37.18, P = 0.00, respectively) 

in the Spring 1994 period while consuming significantly 

less Utah juniper berries (H = 50.70, P = 0.00 and H = 46.00, 

P = 0.00, respectively) during the same period. By RPV, 

Arthropods were consumed significantly more (H = 24.12, 

P = 0.001) in the Spring of 1994 and Summer of 1995. 

Significantly more (H = 16.08, P = 0.01) Arthropods were 

consumed in the Summer of 1995, by RPFO, than in other 

seasonal periods. Misc. Vegetation showed seasonal differences (H = 22.45, P = 0.001) by RPV, but there were no 

significant differences (H = 6.67, P= 0.35) between seasonal 

periods for RPFO. Among the subcategories of Mammals, 

only Rodents showed statistical significance between the 

eight seasonal periods by RPV (H = 21.62, P = 0.002) and 

RPFO (H = 27.40, P = 0.00). Although Mammals and Utah 

juniper berries contributed the majority of food items in the 

diet, it was apparent there were seasonal differences in the 

use of different food items. . 

Leporid and Rodent Availability 

All three census transects were located adjacent to water 

and its accompanying riparian zone. Transect C had the 

most extensive riparian zone. Transect A and B had sections that were;?: 500 m away from water. Transect Band 

C were located at higher elevations, in thicker vegetation, 

and had more variable topography. The lower section of 

Transect A was located in brush flats, while the upper section 

was located in habitat similar to that along Transect B. 

Rodent Assessment-Scent station visitation rates by 

rodents varied month to month from April 1994 to March 

1996 (x = 217.6, SE = 37.5). The scent stations were 

operated regularly for the 24 month period. A total of 170 

visits by rodents were noted during 18 months of census. 

Rain, snow, or frost rendered the stations unreadable six 

months over the study period. These months were usually 

November, January, and February. Thus, Winter 1994 and 

Winter 1995 periods could not be compared with respect to 

Rodents in the diet and rodent activity at the scent stations. 

Spearman's Rank Correlation indicated no significant 

226 

correlation between the amount of rodents in the diet by 

RPFO (Rg= -0.26, P= 0.57) and RPV, (Rg = -0.20, P= 0.65) 

and rodents detected at scent station censusing plates. 

Qualitatively, Rodents in the diet by RPFO and RPV do 

seem to reflect the relative abundance of rodents at scent 

stations from Spring 1994 to Fall 1994 and Summer 1995 

to Fall 1995. 

Leporid Assessment Via Spotlighting-The most observable leporids along the permanent scent station 

transects (via spotlight census) throughout the study were 

cottontail rabbits (Sylvilagus audubonii and S. nuttallii) 

(Durrant 1952). They were observed 13 times and blacktailed jackrabbits (Lepus californicus) 6 times. Leporids 

were most often seen on roads and assigned a perpendicular 

distance of "zero". Leporid density for the study area from 

April 1994 to March 1996 was 42.31 per km2• Number of 

Leporids was also quantified by number per km (# per km) 

for the entire study period with the result of 0.06 leporids 

per km. Leporids observed by spotlighting (leporid per km) 

was strongly correlated with Leporids in diet by RPV erg = 

0.78, P = 0.04) and by RPFO (rg = 0.89, P = 0.02). The highest 

RPFO and RPV ofleporids in the diet occurred in the Spring 

of 1995 and the second highest leporids per km occurred in 

the Spring of 1994 (fig. 1). 

Leporid Assessment Via Fecal Pellet CountsLeporid fecal counts indicated that from April 1994 to 

March 1996 Transect A had the highest mean number of 

fecal pellets with 7.5 pellets per 0.49 m2 (SE = 2.3) and the 

highest leporid density at 14.9 per ha per month for all 

counting periods. The early summer periods showed a higher 

leporid pellet count per plot in August 1994 ( x = 7.4, SE = 3.3) 

than in August 1995 (x = 2.7, SE = 1.1). Leporid availability 

as estimated by leporid per ha per month was not correlated 

with leporids in diet by RPV (rg = 0.42, P = 0.26) or by RPFO 

(rg = 0.46, P = 0.23). However, the August leporid per ha per 

month value was indicative of June, July, and August 

leporid abundance and as such, it is interesting to note that 

leporids in the diet also peaks in the months from AprilSeptember of both 1994 and 1995. Gray fox apparently 

show some response to changing leporid abundance. 

Nutritional and Chemical Analyses 

Of the 214 scats examined, there was not a single j uni per 

seed that was considered to be immature. It was noted from 

our collection of mature and immature berries that mature 

seeds from Utahjuniper berries have a characteristic "dark 

red" or dark "pigment" on the distal 1f3 to Y2 of the seed. 

Immature seeds lack this dark coloration or have a greenish distal end. Seeds of mature Utah juniper berries generally were found with the hard seed coat intact in gray fox 

scat. Seeds not intact were noticeably flawed in some 

natural way or appeared older. Amount of scarification to 

thejuniper seeds found in gray fox scat was not determined. 

Mineral and nutritional analyses were conducted on the 

fleshy coats (hulls) of mature and immature Utah juniper 

berries. Values for 20 different minerals and nutrients 

were obtained from either dry or wet mature and immature 

hulls. Additionally, Ca:P ratio, percent moisture, and percent dry weight of berry that is hull were derived for both 

mature and immature berries. Caloric value was obtained 

USDA Forest Service Proceedings RMRS-P-9. 1999 
c Table 1-Mature Utah juniper berries were collected between July 1995 and June 1996 at Nash Wash. Below is a listing of the means and standard deviation

~ minerals contained in dry hulls of the berries. Sample size of each season was 3, except for percent Moisture in the Summer 1995 (n = 2). Sample s

~ 12, except for percent Moisture (n = 11). 

o 

~ Crude 

(J) Season proteina TNCb Crude fatC ADFd N K Mg Ca P Ca:pe Na Fe Zn Cu Mn 

CD 

~. - - - - - - - - - - - - - - - - - - - - - - Percent - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ppm - - - - - - - - - - - - - - 

o 

~ Summer 5.2± 15.9± 25.8± 28.2± 0.8± 1.9± 0.1± 0.4± 0.1± 4.1± 44.7± 34.0± 7.7± 1.7± 9.7± 

o 1995 0.4 5.6 3.6 2.2 0.1 0.2 0.01 0.03 0.03 0.9 25.8 2.0 2.1 0.6 3.2 

£ July - Sept. 

~ Fall 4.5 ± 28.3 ± 25.8 ± 27.4 ± 0.7 ± 1.9 ± 0.1 ± 0.4 ± 0.1 ± 3.2 ± 25.7 ± 46.7 ± 8.3 ± 4.3 ± 10.3 ± 

t5 1995 0.2 8.5 3.6 2.0 0.03 0.2 0.01 0.1 0.03 1.3 15.9 6.5 0.6 1.5 0.6 

en Oct. - Dec. :IJ 

$:: Winter 4.2± 19.9± 27.1± 32.1± 0.7± 1.8± 0.1± 0.5± 0.1± 4.4± 42.0± 38.7± 7.7± 2.0± 11.3± 

~ 1996 0.7 2.8 0.5 2.8 0.1 0.01 0.01 0.1 0.02 1.4 14.5 4.7 2.1 1.0 1.5 

-b Jan. - Mar. 

~ Spring 3.8± 21.3± 26.8± 28.1± 0.6± 2.0± 0.1± 0.6± 0.1± 6.7± 57.0± 30.7± 8.0± 2.0± 10.3± 

co 1996 0.1 3.0 0.7 0.9 0.01 0.2 0.01 0.1 0.03 2.7 29.8 5.1 1.7 0.0 0.6 

~ Apr. - June 

I\) 

I\) 

-...J 

12-month 4.4 ± 21.3 ± 26.4 ± 28.9 ± 0.7 ± 1.9 ± 0.1 ± 0.5 ± 0.1 ± 4.6 ± 42.3 ± 37.5 ± 7.9 ± 2.5 ± 10.4 ± 

Average 0.6 6.6 2.3 2.75 0.1 0.2 0.01 0.1 0.03 2.0 22.4 7.5 1.5 1.4 1.7 

aCrude protein is the percent of nitrogen in each sample x 6.25. 

bTotal non-structural carbohydrates (TNC) represent the percent of sugars and starch in a sample. 

cCrude fat includes a variety of compounds such as vitamins (A, D, and E), organic acids, oils, and true fats. 

dAcid Detergent Fiber (ADF) reflects the amount of carbohydrates, ash and other cell wall structures not solubilized by acid detergent. Cellulose, lignin, lignified nitrogen, cutin, silic

by these non-solubilized compounds. 

eCa:P is the calcium-to-phosphate ratio. 

Table 2-Mature Utah juniper berries were collected between October 1995 and September 1996 at Nash Wash. Here listed are the 

standard deviations for the Tannins, Phenolics, Carbohydrates (Fructose, Mannose, and Galactose), and calories obtained 

dry juniper berry hulls. Terpenes were obtained from wet mature juniper berry hulls. Sample size of each season was 3 an

size of the 12-month average was 12. 

Season Tannins Terpenesa Phenolicsb Fructose Mannose Galactose 

mg/g mg/g mg/g mg/g 

Fall 44.3 ± 16.2 17.2± 16.4 154.4 ± 46.5 4.0 ± 6.9 14.2 ± 18.4 86.4 ± 92.4 

1995 

Oct. - Dec 

Winter 42.6 ± 13.9 41.0 ± 11.4 198.8 ±69.2 1.5 ± 1.4 7.5 ±6.9 24.4 ± 17.2 

1996 

Jan. - Mar. 

Spring 50.6 ± 16.7 51.6± 18.2 270.4 ±25.3 0.2± 0.3 3.8 ± 3.4 43.1 ± 44.2 

1996 

Apr. - June 

Summer 41.9± 11.3 49.5 ± 9.1 158.3 ± 43.2 0.2 ± 0.3 1.2 ± 1.1 4.5± 3.5 

1996 

July - Sept. 

12-month 44.9 ± 13.0 39.8 ± 18.7 195.5 ± 64.0 1.5 ± 3.4 6.7 ± 9.9 39.6 ± 54.4 

Average 

aTerpenes were measured by "Total Area" per 500 mg fresh weight of tissue divided by 10,000. 

bPhenolics were measured by "Total Area" per 200 mg dry weight of tissue divided by 10,000. 
J\) 

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o 

CD 

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en 

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< 

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CO 

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Table 3--lmmature Utah juniper berries were collected between July 1995 and June 1996 at Nash Wash. Below is a listing of the means and standard deviat

minerals contained in dry hulls of the berries. Sample size of each season was 3, except for percent Moisture in the Summer 1995 (n = 2). Sample s

12, except for percent Moisture (n = 11). 

Crude 

Season proteina TNCb Crude fatC ADFd N K Mg Ca P Ca:pe Na Fe Zn Cu Mn 

- - - - - - - - - - - - - - - - - - - - - - Percent - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ppm - - - - - - - - - - - - - - 

Summer 6A± 12.1 ± 20.5± 33.4± 1.0± 2.0± 0.1 ± 0.3± 0.1 ± 2.8± 30.0± 46.0± 17.3± 2.7± 11.0 ± 

1995 1.1 3.8 1.3 1.9 0.2 0.2 0.0 0.1 0.1 104 9.2 9.6 5.0 2.1 1.7 

July - Sept. 

Fall 6.2± 12.2± 22.7 ± 25.1 ± 1.0± 2.1 ± 0.1 ± 0.2± 0.2± 1.3± 70.3± 44.3± 14.7 ± 4.3± 9.7± 

1995 0.5 0.9 1.1 2.2 0.1 0.2 0.02 0.01 0.02 0.1 63.8 9.5 2.9 0.6 1.5 

Oct. - Dec. 

Winter 5.8± 9.1 ± 22.6± 33.7 ± 0.9± 2.3± . 0.1 ± 0.2± 0.2± 1.5± 47.7 ± 68.0± 13.3 ± 3.3± 10.3± 

1996 0.1 2.7 4.8 2.9 0.02 0.2 0.01 0.01 0.04 004 7.6 35.0 0.6 0.6 1.5 

Jan. - Mar. 

Spring 7.2± 13.0± 23.0± 26A± 1.1 ± 2.2± 0.1 ± OA± 0.2± 2A± 44.7 ± 35.0± 12.0± 4.0± 11.0 ± 

1996 1.5 1.9 3.9 1.1 0.2 0.5 0.02 0.1 0.04 1.0 4.5 8.5 1.0 1.0 2.0 

Apr. - June 

12-month 6A± 11.6± 22.2± 29.6± 1.0± 2.1 ± 0.1 ± 0.3± 0.2± 2.0± 48.2± 48.3± 14.3± 3.6± 10.5± 

Average 1.0 2.7 2.9 4.5 0.2 0.3 0.01 0.1 0.04 1.0 31.6 20.7 3.3 1.2 1.6 

aCrude protein is the percent of nitrogen in each sample x 6.25. 

bTotal non-structural carbohydrates (TNC) represent the percent of sugars and starch in a sample. 

CCrude Fat includes a variety of compounds such as vitamins (A, D, and E), organiC acids, oils, and true fats. 

dAcid Detergent Fiber (ADF) reflects the amount of carbohydrates, ash and other cell wall structures not solubilized by acid detergent. Cellulose, lignin, lignified nitrogen, cutin, sili

by these non-solubilized compounds. 

eCa:P is the calcium-to-phosphate ratio. 

Table 4-lmmature Utah juniper berries were collected between October 1995 and September 1996 at Nash Wash. Here listed 

are the means and standard deviations for the Tannins, Phenolics, and carbohydrates (Fructose, Mannose, and 

Galactose) obtained from the dry juniper berry hulls. Terpenes were obtained from wet immature juniper berry hulls. 

Sample size of each season was 3, except for Terpenes Fall 1995 period (n = 2). Sample size of the 12-month avera

was 12, except for Terpene (n = 11). 

Season Tannins Terpenesa Phenolicsb Fructose Mannose Galactos

mg/g mg/g mg/g mg/g 

Fall 14.9 ± 13.7 38.2 ± 13.9 153.9 ± 92.0 11.3 ± 14.8 14.5 ± 17.9 40.6±37

1995 

Oct. - Dec. 

Winter 0.0 ±O.O 42.6±23.3 109.0 ± 804 8.7 ±9.2 4.8 ±5A 20.3 ± 13

1996 

Jan. - Mar. 

Spring 0.0 ±O.O 51.0±7.1 80.1 ±27.8 12.3 ± 12.4 13.7 ± 17.3 11.6 ± 10

1996 

Apr. - June 

Summer 0.5 ±0.9 42.7 ± 14.9 106.2 ± 51.2 1.7±2.0 3.1 ± 4.0 7.2 ± 10.

1996 

July - Sept. 

12-month 3.9 ±8.9 44.1 ± 14.3 112.3 ± 54.2 8.5 ± 10.1 9.0 ± 12.2 19.9 ±22

Average 

aTerpenes were measured by "Total Area" per 500 mg fresh weight of tissue divided by 10,000. 

bPhenolics were measured by "Total Area" per 200 mg dry weight of tissue divided by 10,000. 
for mature berry hulls. A 12-month average was obtained 

for each component of the berries and data was also grouped 

into the same 3 month periods as those for dietary analysis 

(tables 1-4). 

The mature and immature berries' mineral and nutrient 

components were compared for the 12 months they were 

collected. Fifteen components of juniper hulls were found to 

be significantly different between mature and immature 

juniper berries. Six of the 15 significant components were 

greater in mature than immature juniper hulls. Immature 

hulls had significantly greater contents of minerals, moisture (W = 47.0, P = 0.00), Crude Protein (W = 79.5, P = 0.00), 

and Fructose (W = 99.0, P = 0.00). Mature juniper berries 

had significantly larger values for Ca:P ratio (W = 203.0, 

P = 0.00), Tannin (W = 221.5, P = 0.00), and Phenolics 

content (W = 203.5, P = 0.00). _ 

The greater amounts of some minerals and chemicals in 

mature hulls may appear to be disadvantageous to foxes. 

The National Research Council (NRC) (1982) recommended 

a Ca:P ratio for farm raised silver fox (Vulpes fulva) and 

blue fox (Alapex lagapus) between 1.0:1.0 -1.7:1.0. Mature 

juniper hull Ca:P ratio average over 12 months was 4.6:1.0 

± 2.0: 1.0 (table 4). Studies with herbivores have shown that 

condensed tannins bind to dietary proteins making them 

indigestible. The quantitative ratio of condensed tannins to 

dietary protein and the pH of the stomach acids likely 

controls the process and importance of this binding action. 

Logically, most research on this subject has involved herbivores. Phenolics are considered, in general, to be toxins for 

plant defense (Robbins 1993). 

At first it may appear that the immature juniper hulls 

offer the gray fox significantly more minerals and nutrients. Further evaluation revealed, however, that mature 

juniper berries offer a significantly greater percent of total 

non-structural carbohydrates (TNC) (W = 212.0, P = 0.00) 

and a significantly greater percent of Crude Fat (W = 205.0, 

P = 0.00). TNC represents the percent ofsugars and soluble 

starch in a sample and Crude Fat includes a variety of 

compounds including vitamins (A, D and E), organic acids, 

oils and true fats. Thus, a significantly greater amount of 

digestible energy is available in mature juniper hulls in the 

form ofTNC and Crude Fats than in immaturejuniper hulls. 

The supposedly undesirable aspects of higher Ca:P ratios, higher tannin contents and higher phenolic contents 

must be considered theoretical until further information is 

available on the digestion process and metabolism of the 

gray fox. For example, Robbins (1993) reported Ca:P ratio 

higher than 2:1 can be satisfactorily handled by some 

animals. He further stressed that excess calcium has a far 

lesser effect on phosphorus absorption than the reverse. 

Various animals ranging from invertebrates (Martin and 

Martin 1984: Rhoades and Cates 1976) to vertebrates 

(Robbins 1993) have mechanisms that counter antidigestive 

action oftannins. Robbins and others (1991) has shown that 

some mammals including black bears are adapted for 

consuming tannin containing foods by secreting tannin 

binding salivary proteins. This enables the mammal to 

neutralize tannins as they are ingested. Another factor to 

consider when assuming the effectiveness of tannins to 

bind with proteins is that the optimal pH range for binding 

is between 5 and 6.5 (Rhoades and Cates 1976) and as pH 

level increases or decreases the ability to bind would 

USDA Forest Service Proceedings RMRS-P-9. 1999 

decrease. Since carnivores are known to have a gastric pH 

of about 2.0 (Knowles, personal communication) we conclude that tannins bind dietary proteins less effectively in 

a carnivore stomach. It has also been shown that tannins 

and phenolics can reduce the infectivity of viruses or other 

pathogens (Keating and others 1988; Roming and others 

1992). 

Phenolics can also play diverse metabolic roles when 

ingested. When phenolic-glycosides are hydrolyzed in the 

lab at a pH of 2.0 sugars are cleaved off the phenolic 

compound. In stomachs with a low pH, phenolic-glycosides 

could be hydrolyzed and the resulting sugars would be an 

additional source of nutrition. 

Analysis of juniper berries were grouped into the same 

3-month seasonal periods as those for dietary analyses. 

This allowed us to compare possible seasonal differences in 

mineral and nutritional content. Since collection of berries 

occurred towards the end of the study (1995-1996) and the 

collection of fox scats only partially (Summer 1995, Fall 

1995, and Winter 1996) overlapped the collection of berries, 

the discussion will pertain only to general trends observed 

between dietary contents of scats and chemistry of hulls of 

juniper berries. 

Gray fox apparently prefer only mature Utah juniper 

berries, thus a Kruskal-Wallis Test for statistical differences (p-value = 0.10) was conducted on only mineral, 

nutritional, and chemical components of the mature juniper hulls among the seasonal periods. After determining if 

there were significant differences among groups offactors, 

individual factors were tested for significance against each 

other (Gibbons 1976). 

Eight of the hull components showed seasonal differences at the group level, but in only 5 ofthe 8 seasons could 

seasonal differences be demonstrated within the group. 

Crude Protein (H = 7.23, P = 0.07) was the only non-mineral 

component showing seasonal differences within the group. 

No apparent beneficial patterns were observed for seasonal 

differences among the various components. However, it is 

possible that mature Utah juniper berries were selected in 

greater proportions when small increases in important 

nutrients and minerals were greatest. For example, the 

mean TNC for the entire year was 21.3 percent (SD = 6.6 

percent). During the Fall season when juniper berries were 

taken in large amounts TNC was above the 12-month average 

by 7.0 percent. In addition, the percent Acid Detergent Fiber 

(ADF) during the fall season was lower (x = 27.4, SD = 2.0) 

than the 12-month average (x = 28.9, SD = 2.7). The lower 

percent ADF coupled with the higher percent TNC may allow 

the gray fox to obtain more nutritional benefit by taking this 

seemingly marginal food item in greater amount during the 

winter periods (table 1). 

Ecological Conclusions 

Analysis of gray fox scats for dietary content indicated 

that both RPFO and RPV produced similar results. Gray 

fox extensively used both mature Utah juniper berries and 

mammalian prey. Spotlight sightings of leporids Oeporids 

per km) correlated with leporid content in the diet of gray 

fox. Although rodent censusing at metal scent stations did 

not strongly correlate with rodents in the diet, increase in 

rodent abundance at scent stations and rodents in the diet 

229 
showed some parallels. Thus, gray fox appear to take more 

of both leporids and rodents during the reproductive periods of these prey mammals. 

It is clear that hulls of mature Utah juniper berries 

comprised a large part of gray fox diets in all 8 seasons 

studied. The obvious question is whether or not juniper 

berry hulls are an adequate or inadequate major portion of 

gray fox diets. In the vernacular of foraging strategies, are 

gray fox holding the consequential error of foraging to a 

minimum when ingesting the quantities of juniper berry 

hulls found in this study? Little is known of the digestive 

physiology and metabolism of gray fox. Trapp (1978) claimed 

that berries of Utah juniper alone were sufficient to maintain gray fox in a healthy condition, however, he had little 

data to support his conclusion and he collected berries only 

in the month of December. Trapp's data is similar to that 

reported here with the exception tha(he reports a substantially lower caloric value (3.4 cal per g) than what was found 

in our study (4.2 kcal per g). It should be noted that 

Salomonson's (1978) caloric data on hulls of one-seed juniper (Juniperus monosperma) (4.57 kcaD were similar to our 

findings. 

Though not well studied, the gray fox is one of a few 

homoiotherms and the only mammal known to forage 

extensively on the hulls of Utah juniper berries. Extensive 

seasonal use of juniper berries by avian species has been 

documented. Poddar and Lederer (1982) demonstrated 

that western juniper (Juniperus occidentalis) constituted 

the majority of the Townsend's solitaire (Myadestes 

townsendi) diet in winter. Their study indicated that mature western juniper berries had low percent moisture 

which concentrated more energy and nutritional content 

into hulls of berries. Thus mature berries offered more 

value per unit weight, than the immature berries with 

higher percent moisture. Our analyses of Utah juniper 

berries showed that mature berries had a significantly 

lower percent moisture than immature berries. Due to the 

lower percent moisture it can be shown that if 100 g of 

mature berries were consumed by a gray fox, it would 

obtain twice the amount of nutrients and minerals available in 100 g of immature berries. Furthermore, researcher 

observation indicated it took a human twice as long to 

collect 100 g of immature berries as it did to collect 100 g of 

mature berries. If this is true for a gray fox, then it would 

consume 200 g of mature juniper hull with twice the 

concentration of minerals and nutrients per 100 g, for a 

fourfold increase, in the same amount of time it took to 

consume 100 g of immature juniper hull. 

It is helpful to consider other details of the nutritional 

value of mature Utah juniper berry hulls (tables 1 and 2). 

For example, 100 g of wet mature juniper berries contains 

an average of 4.9 percent of moisture (table 1). After the 

moisture is subtracted we are left with 95.1 g of dry berry. 

Further, we know that an average of65.5 percent (table 1) 

of the remaining weight ofthe berry is hull, which leaves us 

with 62.3 g of hull. Using the 12-month averages from table 

1 and 2 for selected minerals and nutrients we find that 

62.3 g of hull yields 2.73 g of Crude Protein, 13.27 g ofTNC, 

16.45 g of Crude Fat, 18.0 g of ADF, 0.31 g of Ca, 0.06 g of 

P, 2.80 g of Tannins, 93.45 mg of Fructose, 417.41 mg of 

Mannose, 2.47 g of Galactose, and a caloric content of 

261.66 kcal. 

The NRC (1982) provides conflicting data regarding daily 

gross energy requirements for blue and silver fox. This 

230 

report (NRC 1982) roughly estimates that blue and silver 

fox maintenance diets should contain 3,227 kcal of gross 

energy (which is the total combustible energy of feeds 

determined in a bomb calorimeter) per kilogram of dry 

matter. From our data Utahjuniper berries offer 2,751 kcal 

of gross energy per kilogram of dry berry. Without the 

weight of the seed included, which is passed though intact, 

juniper hulls alone would offer 4,200 kcal of gross energy 

per kilogram of dry hull. Thus the juniper hull by itself 

would offer the minimum gross energy needed for maintenance and then some. With the seed included it reduces the 

amount ofkcal available per kilogram of dry matter. However, an occasional addition of a rodent or leporid would 

likely supplement any deficiencies in the kcallevel, protein 

or other needed minerals or nutrients. This is substantiated by Dyson (1965)whofound thaton adietofrodents and 

fruit fed at a rate of 3.8 percent of the fox's total body 

weight, captive gray fox maintained excellent body condition. 

Whether the gray fox can maintain itself well on the level 

of juniper berries shown ingested in this study is best 

answered by the gray fox. White and others (1997), using a 

body condition index designed to emphasis body weight of 

the individual in relation to body size, related that the 

majority of captured gray fox (n = 17) in the NWMA surpassed, achieved or nearly achieved predicted body weight. In 

addition,6 of the 7 juveniles which were captured in months 

of high juniper berry consumption, were at, or nearly at 

(within 0.08), predicted excellent body weight. Furthermore, 3 of 4 females caught in the spring showed signs of 

lactation and thus were reproductive fit. The resident 

breeding population of gray fox in the study follow an 

optimum dietary strategy heavily dependent on Utahjuniper berries. Rodents and leporids are nutritionally valuable 

augmentations to the diet as they are available. 

It is also important to recognize that mature Utah juniper berries exist in large amounts in pinyon -j uni per forests, 

thus providing a large volume of readily available minerals 

and nutrients. They are readily available to gray fox throughout the year since Utahjuniper berries ripen on the tree and 

persist after ripening for up to two years (Johnsen and 

Alexander 1974 as cited in Young and Young 1992). Gray 

fox are adept at climbing trees (Trapp and Hallberg 1975) 

and may use a juniper tree for several purposes including 

resting, as a food source, and as escape cover. When the 

pinyon-juniper forest type occurs near a water source, it 

would appear to provide ideal habitat for gray fox. In White 

and others (1997) study, it was discovered that gray fox 

visit scent stations that provide dense horizontal obscuring 

cover, short distance (~50 m) to escape cover, and are within 

500 m of a water source. Escape Cover was often determined to be Utah juniper trees. What the Utah juniper 

berries may be lacking in nutrients and minerals could 

easily be offset by supplementing with the animal prey 

items as listed. 

Our experimental design did not include measurements 

of possible zoo pharmacological effects of plant secondary 

compounds, in ingested juniper berries, in relation to gray 

fox pathogens as well as internal and external parasites. 

We did hypothesize this could be a minor to major additive 

benefit derived from this behavior but unequivocal tests 

would require extensive laboratory and field studies. External parasite loads were assessed for livetrapped gray fox 

USDA Forest Service Proceedings RMRS-P-9. 1999 
in the study area and infestations were considered minimal 

(White and others, unpublished data). 

In summary, gray fox are likely to receive optimum 

benefits from riparian associated pinyon-juniper habitats 

in several ways. First, juniper berries are an abundant, 

nutritious, and reliable food. Second, juniper trees supply 

both secure and feeding cover. Third, pinyon-juniper communities form ecotones with riparian and other vegetative 

types providing habitats for rodents, leporids, and other 

animals found in the fox diets. Fourth, plant secondary 

compounds found in juniper berry hulls may have 

zoopharmacological, health, benefits for gray fox. 

Our research of gray fox in the pinyon-juniper zone of 

eastern Utah revealed a uniquely strong plant-carnivore 

interaction. Gray fox not only derive several benefits from 

inhabiting this zone but also provide a valuable benefit to 

juniper community dynamics in the form of seed dispersal. 

Since scat contained a mixture of metabolic residue from 

several food items (that is mammal hair) andjuniper seeds, 

gray fox provided Utah juniper berry seeds with a natural 

"mulch" of nitrogen and other minerals. The large seeds of 

Utah juniper suggests a seed dispersal strategy utilizing 

the larger, omnivorous, mammals in the Order carnivora 

such as gray fox, coyote, ringtail and black bear. These have 

highly acidic stomach environments that may actually 

contribute to the efficient digestion of berry hulls. During 

ingestion, gray fox do not have to break a shell or husk in 

order to benefit fromjuniper berry hulls and this may help 

explain why they do not actively feed on pinyon nuts or 

acorns. Other fleshy fruits available but not eaten contain 

high amounts of water in proportion to other nutrients. 

Gray fox occur in riparian zones and thus feed for nutrition 

not moisture. Our study revealed that members of the 

Order carnivora known to inhabit pinyon-juniper zones, 

and the gray fox in particular, are unusually strong contributors to the community structure, dynamics and function of the Utah juniper dominated ecosystem. 

Acknowledgments 

The study was a cooperative agreement between the 

Utah Division of Wildlife Resources and Brigham Young 

University. Appreciation is expressed to Athena Meneses 

for her assistance with scat preparation, diet analyses, and 

preparation of juniper berries for chemical analysis. We 

would also like to thank Athena and Dr. Richard Kellems 

for their evaluation of gross energy of juniper berries. 

Appreciation is expressed to the following at the Monte L. 

Bean Life Science Museum for help with prey identification 

in their area of expertise: Dr. Duke Rogers, Dr. Kimball 

Harper, Dr. Richard Baumann, Dr. Stephen Wood, Dr. 

Douglas Cox, and Dr. Clayton White. 

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USDA Forest Service Proceedings RMRS-P-9. 1999 
Habitat Relationships of Amphibians and 

Reptiles in the Inyo-White Mountains, 

California and Nevada 

Michael L. Morrison 

Linnea S. Hall 

Abstract-The distribution and abundance of he rpetofa una was 

documented in the Inyo and White mountain ranges of Inyo and 

Mono counties, eastern California. Fourspecies of amphibians and 

26 species of reptiles were located in pinyon-juniper (Pinus 

monophylla-Juniperus osteosperma) woodland. Thirteen of the 26 

reptile species recorded were snakes; the distribution of most 

snakes remains poorly understood. The concentration of skinks 

(Eumeces spp.) at springs identified the importance of wet areas 

for these species. Results indicated the generally unrecognized 

diversity of herpetofauna present in pinyon-juniper woodlands, 

and highlight specific research and management needs. 

The Inyo and White mountains are the predominant 

ranges on the western border of the Great Basin. Because 

of their proximity to the Sierra Nevada, the Inyo-White 

mountains would be expected to harbor a larger diversity of 

fauna than found in more easterly, interior ranges. However, this diversity remains virtually undescribed; there 

have been few surveys of the fauna in the Inyo-White 

mountains, and research in the pinyon-juniper (Pinus 

monophylla-J uniperus osteosperma) zone is especially lacking. For example, only a few studies have documented the 

distribution and habitat affinities of amphibians and reptiles in these ranges (Papenfuss 1986; Macey and Papenfuss 

1991a,b). Better quantificati9n of fauna in these areas is 

necessary before resource professionals can develop comprehensive and inclusive management plans. 

The goal of our 6 year study was to document the distribution, abundance, and habitat affinities of amphibians 

and reptiles (herpetofauna) in the pinyon-juniper zone of 

the Inyo-White mountains, eastern California and western 

Nevada. For this paper, we have also included results from 

the poorly studied, upper elevation bristlecone pine-limber 

pine (Pill llS longaeua-P. flexilis) forest zone. 

Study Area 

The Inyo-White mountains rise from 1,515 to 4,245 m 

elevation and are east of, and run parallel to, the Sierra 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Michael 1. Morrison is Adjunct Professor, and Linnea S. Hall is Assistant 

Professor, Wildlife Biology, Department of Biological Sciences, California 

State University, Sacramento, CA 95819. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Nevada Mountains. The pinyon-juniper woodland predominates both ranges between about 1,800 and 2,900 m elevation, and is characterized by an increasing concentration of 

pinyon, and decreasing amount of juniper, with increased 

elevation. The shrub layer is sparse and composed primarily of sagebrush (Artemesia tridentata) and bitterbrush 

(Purshia glandulosa and P. tridentata), intermixed with 

Mormon tea (Ephedra viridis), rabbitbrush (Chrysothamnus 

nauseosus and C. viscidiflorus), cactus (Opuntia and 

Echinocereus spp.), and other, less common grasses and 

herbaceous plants. 

The bristlecone pine-limber pine forest begins at the 

upper edge of the pinon-juniper woodland and extends up 

to about 3,500 m. It is composed of varying mixtures of the 

two pine species, with a sparse understory composed of 

sagebrush and mountain mahogany (Cercocarpus ledifolius). 

There are very few large meadows; the largest riparian! 

meadow location, Cottonwood Basin, is located in the White 

Mountains (at 3,300 m), and is characterized by linear 

stretches of aspen (Populus tremuloides) and willow (Salix 

spp.), but little cottonwood (Populus sp.). A thorough description of the environment and flora of these ranges was 

given by Powell and Klieforth (1991) and Spira (1991), 

res pecti vely. 

Methods 

We determined the distribution of herpetofauna throughout the ranges by searching the literature, museum specimen records, field notes of previous workers, and by conducting our own surveys. 

We examined all specimen records through 1988 in the 

Museum of Vertebrate Zoology (MVZ; University of Calif ornia, Berkeley) and the Los Angeles County Natural History 

Museum (LACNHM). 

We examined and summarized the field notes of expeditions conducted by teams from the Museum of Vertebrate 

Zoology in spring and summer 1917,1942, and 1954. Notes 

from smaller and shorter-term field trips were also 

examined. 

The only comprehensive summary ofthe herpetofauna of 

these ranges was by Papenfuss (1986) and Papenfuss and 

Macey (1991a,b), who visited the ranges, and also summarized literature and museum records. They conducted sampling transects across the southern Inyo Mountains, across 

Westgard Pass (central in the ranges), and in the northern 

White Mountains. 

233 
Landscape Distribution 

The major east-west, paved travel route across the ranges 

is State Highway 168. This road crosses the central part of 

the ranges at Westgard Pass (2,100 m elevation). We drove 

this road to search for living or road-killed animals from the 

lower edge ofthe pinyon-juniper vegetation on the east and 

west sides of Westgard Pass, a total distance of about 

15 km. At least 500 trips were made during daylight hours 

between May and September, 1987-1992. 

The major north-south road in the ranges is the White 

Mountain Road, which begins at Westgard Pass and runs 

north to near the summit of White Mountain Peak. We 

drove this road from Westgard Pass up to 3,100 m in the 

bristlecone pine-limber pine zone, a total distance of about 

20 km, on at least 200 occasions during daylight, MaySeptember 1987-1992. 

Records of all anecdotal observations of herpetofauna 

were also made during our studies of general vertebrate 

natural history in the ranges, which spanned a total of 30 

months in 1987-1992, or about 75 person-months of effort. 

Macrohabitat Relationships 

We established both short- and long-term pitfall trapping 

grids. Short-term grids were placed as follows: (1) Montenegro 

Springs, southern White Mountains (T7S, R34E, sec. 36), 

opened for 1,872 trap days in June-August 1989; (2) Little 

Cowhorn Valley, central lnyo Mountains (T9S, R36E, sec. 15), 

opened for 2,337 trap days in June-August 1991; and 

(3) Waucoba Pass, central lnyo Mountains (T9S, R36E, sec. 

28), opened for 1,189 trap days in July-August 1991. 

We established three longer-term pitfall grids (T7S, R35E, 

sec. 30-32) to intensively sample the pinyon-juniper zone. 

Each grid was 4 ha in size. Thirty-six pitfalls were placed at 

about 25 m intervals on each grid. Pitfalls were constructed 

of two number 10 cans as described by Corn (1994); small 

holes were punched in the bottom of each can to allow water 

to drain. Each pitfall was covered by a raised wooden lid; no 

drift fences were used. Pitfalls were run as live traps and 

were checked at least every 2 days from late May to early 

September, 1989-1991, for a total of about 5,300 trap days 

per grid per year (48,000 total trap days for the study). Each 

capture was identified, the sex and age determined, and one 

toe was clipped to identify recaptures. 

Habitat Analyses 

We quantified the habitat attributes ofthe herpetofauna 

on the three long-term pitfall grids by establishing 20 m 

radius plots centered on each pitfall location. Within each 

plot we measured tree density; the cover of shrubs, grasses 

and herbaceous species; and cover of rocks and downed 

material using point-intercepts bisecting the plot. 

Results ------------------------------------

Distribution at the Landscape Scale 

A total of four species of amphibians and 26 species of 

reptiles have been observed in the pinyon-juniper zone of 

234 

the lnyo-White mountains (table 1). The western toad 

(scientific names in table 1), black toad, and northern 

leopard frog are extremely restricted in distribution and 

are only found in a few springs and ponds. The lnyo 

Mountains salamander is the only verified salamander 

species in these ranges; the salamander occurs in many 

springs and seeps in the southern lnyo Mountains. There 

are, however, several anecdotal records of an unknown 

salamander species made by reliable observers at high 

elevations in the northern White Mountains (table 1). 

Thirteen of the 26 reptile species recorded in the pinyonjuniper zone were snakes. The speckled rattlesnake and 

striped whipsnake were the only snakes seen commonly 

throughout the zone (personal observation). We apparently 

made the first identification of a Nevada shovel-nosed 

snake, and extended the elevational range of the gopher 

snake (to 3,300 m) into the Cottonwood Basin, White 

Mountains. Additionally, we made an observation of the 

western rattlesnake that extended the known range ofthis 

species south in the White Mountains to near Westgard 

Pass (table 1). 

Eight of the reptile species occurred only at the lower 

edges ofthe pinyon-juniper zone, whereas the remaining 15 

species were found throughout the zone. The eight species 

at the lower edge ofthe woodland are principally associated 

with lower elevation (desert scrub) vegetation and apparently barely reach into the pinyon-juniper zone. 

Seven species, all reptiles, extended up into the bristlecone pine-limber pine vegetation zone; no verified species 

was unique to the latter zone (table 1). The only exception 

found to date could be the possible salamander discussed 

above. Most species occurred only into the lower edge of the 

bristlecone pine-limber pine zone, with the exceptions of 

the sagebrush lizard, western fence lizard, and perhaps the 

side-blotched lizard. 

Macey and Papenfuss (1991a,b) reported observations of 

two amphibian, three lizard, and five snake species in the 

pinyon-juniper zone of the lnyo and White mountains that 

we did not observe (table 1). 

Macrohabitat Relationships 

Short-term pitfall trapping did not locate any new species nor extend the range of any known species. Sagebrush 

lizards and western fence lizards were captured at Little 

Cowhorn Valley (n = 12 sagebrush and 7 fence lizards); only 

fence lizards (n = 8) were captured at Waucoba Pass; and 

both Gilbert en = 2) and western (n = 4) skinks were 

captured at Montenegro Springs. 

We captured a total of seven species on our three permanent trapping grids between 1989-1991 (table 2). Overall, 

the sagebrush lizard was the most numerous species captured, accounting for 51.3 percent of all captures. The 

western fence lizard (31.7 percent) was the only other 

species that accounted for >10 percent of total captures. 

The side-blotched lizard was captured regularly but accounted for only 8.9 percent of all captures. The western 

whiptail was captured regularly (4.2 percent) but only on 

one grid ("Westgard"). The western skink (2.1 percent) and 

Gilbert skink (1.8 percent) were captured infrequently but 

occurred on all three grids. The desert night lizard CO.1 

percent) was captured only on one grid ("Pinyon") (table 2). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 1-Summary of distribution of amphibians and reptiles from the Inyo and White mountains, California and Nevada. M&P refers to Macey 

Batrachoseps campi [I nyo Mountains salamander] 

M&P and Marlow et al. (1979) summarized the numerous 

records of this relictual species in the Inyos; not recorded from 

the Whites. Papenfuss (1986) stated that there were reliable 

reports of salamanders (species unknown) from above 3,000 m 

in the Whites. We did not locate at new locations. 

Bufo boreas [Western toad] 

M&P stated has been found above 2,100 m in northern Whites. 

We observed what were likely toad tadpoles in a seasonal 

waterhole north of Montgomery Pass, northern Whites. 

Bufo exsul [Black toad] 

M&P noted introduced to Batchelder (Toll House) Spring but 

may be extinct there. We thoroughly searched this spring 

throughout our study and located no amphibians. 

Rana pipiens [Northern leopard frog] 

M&P reported from 2,300 m on east side of Whites below 

Boundary Peak. We did not locate at other sites. 

Cnemidophorus tigris [Western whiptail] 

M&P reported to 2,300 m in both ranges. We saw to 2,500 m 

throughout Inyos. 

Xantusia vigilis [Desert night lizard] 

M&P reported to at least 2,100 m in the southern Inyos north to the 

Mono County line. We found near Westgard Pass at 2,250 m. 

Phrynosoma platyrhinos [Desert horned lizard] 

M&P reported to about 2,300 m in both ranges. We had no 

observations. 

Cole onyx variegatus [Western banded gecko] 

M&P stated the northernmost locality as Westgard Pass, but we 

found no references for specimens or sighting above about 

1,700 m. 

Gerrhonotus panamintinus [Panamint alligator lizard] 

M&P reported as both ranges below 2,300 m. We saw one dead 

on the road at 2,200 m near Westgard Pass. 

Eumeces gilberti [Gilbert skink] 

M&P reported as present to 2,700 min Inyos north to Silver 

Creek and Wyman canyons. We captured both this species and 

the western skink (see below) at the same localities near 

Westgard Pass. 

Eumeces skiltonianus [Western skink] 

M&P called this a high elevation species not found below 2,300 m 

and may occur to 3,300 m. They had only a single record of the 

western skink from the ranges. We captured numerous 

individuals in pitfalls near Westgard Pass. 

Crotaphytus insularis bicinctores [Great Basin collared lizard] 

M&P reported as throughout ranges to lower extent of the 

pinyon-juniper woodland. However, museum specimens indicate 

occurrence to 2,300 m in Silver Canyon. We also found road 

specimens at 2,200 m near Westgard Pass, and Williamson 

(1954, field notes) reported from 2,200 m in Wyman Canyon. 

Gambelia wislizenii [Long-nosed leopard lizard] 

M&P reported as throughout the ranges below 2,300 m. We 

made no observations. 

Sceloporus graciosus [Sagebrush lizard] 

M&P reported below about 3,000 m. We captured several 

individuals at 3,300 m in Cottonwood Basin, White Mountains. 

Sceloporus magister [Desert spiny lizard] 

M&P reported below 2,300 m in both ranges. We observed at 

2,300 m at Westgard Pass. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Sceloporus occidentalis [Western fence lizard] 

M&P reported up to 3,000 m. We captured numerous individuals 

up to this elevation. 

Uta stansburiana [Side-blotched lizard] 

M&P reported throughout the ranges below 2,600 m. There are, 

however, museum specimens from 3,000 m at the Shulman 

Grove, White Mountains. We saw active ones near Westgard 

Pass as late as mid-November. 

Thamnophis elegans [Western terrestrial garter snake] 

M&P reported as occurring near streams on eastern slopes of 

Whites to at least 2,700 m. We also observed 1 in pinyon-juniper 

near Westgard Pass, which was at least 2 km from permanent 

water. 

Crotalus mitchelli [Speckled rattlesnake] 

M&P reported throughout ranges to 3,000 m. We observed 

infrequently in pinyon-juniper between 2,000-3,000 m. 

Crotalus viridis [Western rattlesnake] 

M&P stated range as northwestern slopes of Whites only. 

However, we found an adult at Montenegro Spring (2,100 m), 

which extends the range of this species south to near Westgard 

Pass. 

Hypsiglena torquata [Night snake] 

M&P reported as throughout the ranges below 2,300 m. We had 

no observations. 

Lampropeltis getulus [Common kingsnake] 

M&P reported as throughout the ranges below 2,300 m. We had 

no observations. 

Masticophis flagellum [Coachwhip] 

M&P reported as entire region below about 2,000 m. We had no 

observations. 

Mastocophis taeniatus [Striped whipsnake] 

M&P reported as entire region from 1,500 to 2,750 m. We 

observed them fairly frequently and found a road kill on 6 

December at 2,300 m near Westgard Pass. 

Pituophis melanoleucus [Gopher snake] 

M&P reported as throughout ranges below 2,600 m. We 

captured several in Cottonwood Basin, White Mountains, at 

3,200 m. 

Rhinocheilus lecontei [Long-nosed snake] 

M&P described as throughout the ranges below 2,000 m; we did 

not locate any individuals in the pinyon-juniper zone. 

Salvadora hexalepis [Western patch-nosed snake] 

M&P described as throughout the ranges below 2,100 m. We 

collected a road kill near Westgard Pass (2,300 m). 

Sonora semiannulata [Ground snake] 

M&P stated as presumed to occur throughout the White-Inyo 

mountains region below 2,000 m. We did not locate during any 

of our surveys. 

Tantilla hobartsmithi [Southwestern black-headed snake] 

M&P stated as occurring on western slopes of Inyos. We did not 

locate. 

Chionactis occipitalis talpina [Nevada shovel-nosed snake] 

We recovered 2 road kills near Westgard Pass during 1991: 3 

June at 2,100 m and 18 June at 2,000 m; these are apparently 

the first records of this species for these ranges. 

235 
Table 2-Relative abundance of herpetofauna on three long-term pitfall grids, Inyo 

and White mountains, California, 1989-1991. 

Species Pinyon Cedar Westgard Total 

--- .. _------ Number (percent) on grids - - - - - - - - - -

Gilbert skink 5 (1.1 ) 11 (3.7) 11 (2.1) 27 (2.1 ) 

Western skink 5 (1.1 ) 15 (5.0) 3 (0.6) 23 (1.8) 

Sagebrush lizard 195 (43.4) 169 (56.1) 284 (55.4) 648 (51.3) 

Western fence 

lizard 196 (43.7) 93 (30.9) 111 (21.6) 400 (31.7) 

Side-blotched 

lizard 48 (10.7) 13 (4.3) 51 (9.9) 112 (8.9) 

Western whiptail 0 0 53 (10.3) 53 (4.2) 

Total 449 301 513 1263 

Table 3-Description of three long-term pitfall grids used in the Inyo and White 

mountains, California, 1989-1991. For variables with P < 0.05 (analysis of 

variance). mean values that are significantly different are denoted by different 

capital letters (n = 41 plots/grid). 

Pin~on 

Variable x SO 

Tree density (no'/ha) 

Pinyon 40A 27.4 

Juniper 7A 12.2 

Total 47B 30.1 

Cover (percent) 

Shrubs 4 4.7 

Herbs 2 2.8 

Down wood 1 1.2 

Rock 14AB 4.6 

The highest abundance of sagebrush lizards was on the 

Westgard grid, whereas the Pinyon grid had the highest 

abundance of fence lizards. Westgard and Pinyon had 

substantially more side-blotched lizards than did the third 

grid ("Cedar"). 

The three grids differed significantly in the density of 

pinyon trees, although the Westgard grid was much lower 

in density than the other two grids. In contrast, Westgard 

had a significantly higher density of juniper trees than 

either of the other two grids (table 3). The cover of other 

plants and substrates was similar among sites. 

Discussion ------------------------------- Our landscape-level surveys of the ranges, when combined with previous field surveys, highlighted the diversity 

of he rpetofa una in the pinyon-juniper woodland. Although 

the herpetofauna was predominated by sagebrush and 

western fence lizards, numerous other species of lizards 

and snakes resided in the woodland. Toads and frogs were 

extremely restricted in their distribution, being found primarily in wet locations in the northern White Mountains. 

Anecdotal sightings indicated that an unidentified species 

of salamander may exist at high elevations in the White 

Mountains. These records, in addition to the apparent 

affinity of skinks for wet areas, indicate that future 

236 

Cedar Westgard 

x SO x SO p 

63B 31.7 24C 16.2 <0.01 

2A 3.8 36B 16.7 <0.01 

65A 31.9 60A 21.1 0.01 

5 5.3 3 2.7 0.24 

1 1.8 1 2.0 0.59 

1 1.6 1 1.4 0.49 

16A 5.0 18B 7.2 0.05 

sampling efforts should be concentrated in and around 

springs throughout the ranges. 

We also identified the presence of many species of small 

snakes. However, neither our survey efforts nor those 

conducted previously (that is, Papenfuss 1986; Macey and 

Papenfuss 1991a,b; unpublished field notes) were of adequate intensity to clarify the range-wide distribution, 

abundance, and specific habitat affinities of these species. 

Our short-term pitfall trapping did not yield any new 

species nor extend the previously known ranges of any 

species. Results from Montenegro Springs did, however, 

exemplify both the co-occurrence of the western skink and 

Gilbert skink, and an apparent affinity of these species for 

wet areas. Although both species of skink were found away 

from springs in pinyon-juniper woodland, they reached 

their greatest abundances near the spring. It appears that 

wet areas (that is, springs, seeps) may function as highquality habitat for skinks. 

Our longer-term pitfall grids identified the primary 

herpetofauna of the pinyon-juniper woodland as one predominated by sagebrush and western fence lizards, with a 

regular occurrence (but at much lower abundance) of sideblotched lizards and Gilbert and western skinks. Whiptails 

were added to the community only on the Westgard grid. 

Westgard had the lowest density of pinyon trees, but a 

much higher density of juniper trees compared to the other 

USDA Forest Service Proceedings RMRS-P-9. 1999 
two grids. The Westgard grid had a southern aspect, whereas 

the other two grids were oriented primarily westward. The 

presence of juniper and drier conditions on Westgard probably led to the higher overall abundance of animals and 

presence of whip tails on the grid. 

Night lizards were only captured on the Pinyon grid. 

Cursory surveys of the grid located additional adult night 

lizards under thin horizontal rock slabs. Thus, it appears 

that night lizards may be more abundant than indicated by 

the pitfall data, with their occurrence restricted to specific 

microsites. 

In summary, we refined the distributional records for 

many species, including the identification of several new 

records for the mountains as a whole, and the pinyonjuniper zone specifically. Our results demonstrate the generally unrecognized diversity of herpetofauna present in 

the pinyon-juniper woodland, and highlight specific research and management needs that could lead to conservation of these species into the future. 

Acknowledgments ______ _ 

We thank H. Welsh, A. Lind, A. Kuenzi, J. Keane, P. 

Aigner, L. Nordstrom, L. Baker, J. Block, and L. Ellison for 

field assistance; and E. Phillips and D. Trydahl at the White 

Mountain Research Station (WMRS), in Bishop, California, 

for logistical support. Funding was provided through WMRS 

and V.C. Graduate fellowships to LSH. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

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Heyer, W. R. and others, eds. Measuring and monitoring biological diversity. Standard methods for amphibians. Washington, 

D.C.: Smithsonian Institution Press: 109-117. 

Macey, J. R.; Papenfuss, T. J. 1991a. Amphibians. In: Hall, C. A. 

Jr., ed. Natural History of the White-Inyo range, eastern California. Berkeley, CA: California Natural History Guide 55, 

University of California Press: 277-290. 

Macey, J. R; Papenfuss, T. J. 1991b. Reptiles. In: Hall, C. A. Jr., 

ed. Natural History of the White-Inyo range) eastern California. 

Berkeley, CA: California Natural History Guide 55, University 

of California Press: 291-360 

Marlow, R W.; Brode, J. M.; Wake, D. B. 1979. A new salamander, 

genus Batrachoseps, from the Inyo Mountains of California, 

with a discussion of relationships in the genus. Natural History 

Museum, Los Angeles County Contribution to Science 308:1-17. 

Papenfuss, T. J. 1986. Amphibian and reptile diversity along 

elevational transects in the White-Inyo range. In: Hall, C. A. Jr.; 

Young, D. J., eds. Natural history of the White-Inyo range, 

eastern California and western Nevada, and high altitude physiology. Bishop, CA: White Mountain Research Station Symposium, vol. 1: 129-136. 

Powell, D. R; Klieforth, H. E. 1991. Weather and climate. In: Hall, 

C. A. Jr., ed. Natural History of the White-Inyo range, eastern 

California. Berkeley, CA: California Natural History Guide 55, 

Univ. of California Press: 3-26. 

Spira, T. P. 1991. Plant zones. In: Hall, C. A. Jr., ed. Natural 

History of the White-Inyo range, eastern California. Berkeley, 

CA: California Natural History Guide 55, Univ. of California 

Press: 77-107. 

237 
Sage Grouse Response to Pinyon-Juniper 

Management 

Michelle L. Commons 

Richard K. Baydack 

Clait E. Braun 

Abstract-The response of Gunnison sage grouse (Centrocercus 

minimus) to management of pinyon-juniper (Pinus edulis -

Juniperus spp.) was studied in southwestern Colorado during 

1994 through 1997. Near Crawford, CO, numbers of male sage 

grouse using leks within 100 m of live pinyon-juniper were depressed because of increased raptor presence and predation associated with coniferous trees/shrubs. Removal, by cutting, of pinyon-juniper trees/shrubs in association with brush-beating to 

reduce height of mountain big sagebrush and deciduous brush 

resulted in doubling numbers of male sage grouse counted on 

treatment leks in years 2 and 3 posttreatment. Clearing of young 

age classes of pinyon-juniper that have spread into sagebrush 

shrub-steppe appears to have great merit for enhancing sage 

grouse use of treated areas through increased s"urvival, productivity, and recruitment. This is especially significant in management 

of small populations of sage grouse in highly fragmented habitats 

which may be locally threatened with extirpation. 

Sage grouse (Centrocercus spp.) are dependent upon 

sagebrush (Artemisia spp.) shrub- steppe throughout their 

distribution in western North America (Patterson 1952). 

While exact composition of the original sagebrush shrubsteppe is unknown, both grazing by wild ungulates and fire 

commonly occurred, especially in higher preci pi tation zones. 

Grazing of this habitat type increased following settlement 

resulting in more bare mineral soil. At the same time, fire 

frequency has generally decreased although intensity has 

increased in some areas (Bunting 1994). Primarily because 

of these 2 factors, seedlings of pinyon pine (Pinus spp.) and 

juniper (Juniperus spp.) have become established in sagebrush-dominated lands in the last 40-60 years. 

Populations of sage grouse have declined in many areas 

of their former range (Connelly and Braun 1997). These 

declines are most notable where population size is constrained by habitat limitations including loss, fragmentation, and degradation of sagebrush-dominated ecosystems. 

Extinctions of local populations of sage grouse have occurred, especially at the periphery of the original distribution (Johnsgard 1973, Braun 1995). 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Michelle L. Commons and Richard K. Baydack are with the Natural 

Resources Institute, University of Manitoba, Winnipeg, Manitoba, Canada 

R3T 2N2. Clait E. Braun is with the Colorado Division of Wildlife, 317 West 

Prospect Road, Fort Collins, CO 80526. 

238 

Management of sagebrush-dominated habitats is necessary if viable populations of sage grouse are to persist. Enhancement of habitats to benefit sage grouse will require 

management prescriptions and experiments to learn if treatments result in increased population size and/or distribution. 

The objective ofthis paper is to describe apparent sage grouse 

population response to pinyon-juniper treatment. 

Study Area 

The area studied is in northwest Montrose County, Colorado between the town of Crawford and the Black Canyon 

ofthe Gunnison National Monument. Sage grouse occur on 

lands administered by the Bureau of Land Management 

and National Park Service, with substantial areas in private ownership. Dominant vegetation types include sagebrush (A. tridentata vaseyana, A. nova), pinyon-juniper, 

and mountain brush (Quercus gambelii, Amelanchier spp., 

Symphoricarpos spp.) with frequent intermixing of habitats depending upon elevation, aspect, slope, and past 

vegetation treatments (including grazing by domestic livestock and wild ungulates) (Commons 1997). 

Methods 

Numbers of male sage grouse on previously «1994) 

located leks were counted in 1994 (pretreatment), 1995 (1-

year posttreatment) and 1996-97 (2-3 years post treatment) during April and May at 7-10 day intervals. Searches 

for sage grouse mortalities were made periodically throughout the display season by walking lek sites and adjacent 

habitats. Sage grouse were trapped at night (Giesen and 

others 1982) where they roosted on or near leks. Radio 

transmitters affixed by elastic cord or plastic collars were 

attached to selected sage grouse. Radio-marked birds were 

systematically followed to identify habitats used. Short 

«1m) pinyon-juniper trees, sagebrush, and associated deciduous shrubs were brush beat with a tractor-drawn rotary mower. Taller (>1m) trees were cut using a chain saw 

with limbs and stems being scattered. Brush beating was 

initiated in August 1994 with additional sites being treated 

in September - October 1996. Hand cutting oftrees near lek 

sites occurred as time permitted in fall and early winter 

1994, and continued away from lek sites into 1997. 

Results 

Three leks were active in 1994-95 and 1996-97 (table 1). 

No new or unknown active lek sites were found during the 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 1-Peak counts of male sage grouse on leks, Fruitland Mesa, 

Colorado, 1994-95 vs. 1996-97. 

Lek 1994 1995 1996 1997 

Dam 3 6 18 13 

Range Cone 11 9 19 20 

Section 35 8 6 9 8 

Totals 22 21 46 41 

study period. Total males counted increased from 21-22 (1994-

95) to a 2-year average of 43 (1996-97). This doubling in 

number of males counted primarily occurred at 2 sites where 

removal of pinyon-juniper was most pronounced. Mortality 

searches at lek sites in 1994 located the remains of 7 male 

sage grouse. No mortality searches were conducted in 1995 

and no mortalities were found at lek sites in 1996-97. 

Twelve sage grouse were captured and fitted with radio 

transmitters in 1996. Habitats used by these birds indicated avoidance of pinyon-juniper except during September - November when sage grouse extensively used sagebrush-dominated areas with scattered trees 22 m in height 

(table 2). Pinyon-juniper trees were avoided from June 

through August when sage grouse selected disturbed areas 

(burned, disked, rotochopped) that had an abundance of 

succulent forbs. 

Discussion -------------------------------- The apparent size of the sage grouse population on 

Fruitland Mesa as measured by counts of males on leks 

doubled between 1994-95 and 1996-97. This increase was 

believed to have resulted from decreased mortality of males 

during the breeding season and improved survival of both 

males and females. Prior to treatment (cutting of pinyonjuniper trees), raptors were observed perching and hunting 

from trees adjacent to lek sites and all documented mortalities were attributed to raptor..s. However, effects of cutting 

of pinyon-juniper trees were confounded as sagebrush at 

lek sites was also beat thereby increasing the ability of sage 

grouse to detect predators at greater distances. 

Sage grouse clearly avoided pinyon-juniper trees during 

the breeding and summer periods. Studies elsewhere in 

Colorado indicate avoidance of pinyon-juniper trees throughout the year. At Fruitland Mesa, invasion ofpinyon-juniper 

trees in the last 30-60 years has reduced the amount of area 

where trees do not occur. At present, there are few areas, 

outside ofthose treated in this study, where pinyon-juniper 

trees do not occur. 

We do not know if increased survival of males at leks 

translates to increased survival of females as counts of 

females at leks are problematic because of short, irregular 

attendance periods. Our observations of hens and hens 

with broods during other field activities in this area suggest 

the population markedly increased between 1994-95 and 

1996-97. Whether the apparent increase can be sustained 

or further enhanced is not known. It is also remarkable the 

sage grouse population apparently responded quickly to 

treatments designed to immediately resolve a local problem. Outside of predation, mortality of this population 

appears low as no hunting is allowed and primary roads do 

not traverse the area. This small, isolated population appears to be habitat limited. Removal ofpinyon-junipertrees 

could increase usable habitat size by at least 100 percent. 

Acknowledgments ______ _ 

This study was funded by the Colorado Division of Wildlife through Federal Aid in Wildlife Restoration Project 

W-167-R and the Montrose District of the Bureau of Land 

Management. We thank the private landowners for access 

to their land and support for treatments in their grazing 

allotments. We especially thank D. D. Homan and P. D. 

Jones of the Colorado Division of Wildlife and R. D. Welch 

of the Bureau of Land Management for advice, technical 

support, and assistance throughout the study. 

References _________ _ 

Braun, C. E. 1995. Distribution and status of sage grouse in 

Colorado. Prairie Nat. 27: 1-9. 

Bunting, S. C.1994. Effects offire onjuniperwoodland ecosystems 

in the Great Basin. In: S. B. Monsen and S. G. Kitchen, comps. 

Proceedings-ecology and management of annual rangelands. 

Gen. Tech. Rep. INT-GTR 313. Ogden, UT: U. S. Department of 

Agriculture, Forest Service, Intermountain Research Station: 

53-55. 

Commons, M. L. 1997. Movement and habitat use by Gunnison 

sage grouse (Centrocercus minimus) in southwestern Colorado. 

M.N.R.M. Practicum, Univ. Manitoba, Winnipeg. 108 pp. 

Connelly, J. W., and C. E. Braun. 1997. Long-term changes in sage 

grouse Centrocercus urophasianus populations in western North 

America. Wildl. Biol. 3: 229-234. 

Giesen, K. M., T. J. Schoenberg, and C. E. Braun. 1982. Methods for 

trapping sage grouse in Colorado. Wildl. Soc. Bull. 10: 224-231. 

Johnsgard, P. A. 1973. Grouse and quails of North America. Univ. 

Nebraska Press, Lincoln. 553 pp. 

Patterson, R. L. 1952. The sage grouse in Wyoming. Sage Books, 

Inc., Denver, CO. 341 pp. 

Table 2-Distance (m) of radio-marked sage grouse from pinyon/juniper trees ~ 2 m tall, 

June- November 1996, Fruitland Mesa, Colorado. 

Jun Jul Aug Jun-Aug Sep Oct Nov Sep-Nov 

Distance (22) (27) (16) (65) (16) (6) (7) (29) 

m _ ... _---_ ............ ------- Percent of locations ..... _---_ .............. - ... - ... _--

<50 14 15 6 12 50 100 29 55 

50-100 4 0 6 3 12 0 0 7 

>100 82 85 88 85 38 0 71 38 

( ) = number of relocations of radio-marked sage grouse. 

USDA Forest Service Proceedings RMRS-P-9. 1999 239 
Pinyon-Juniper Woodlands as Sources of 

Avian Diversity 

Kathleen M. Paulin 

Jeffrey J. Cook 

Sarah R. Dewey 

Abstract - Results of breeding bird point counts in mature pinyonjuniper woodlands are described and compared to data from seven 

other forest habitats common in northeastern Utah. Pinyon-juniper bird communities ranked second in the percentage of obligate 

and semi-obligate species, third in total number of individuals 

counted, and fourth in species richness and diversity. Bird species 

assemblages in pinyon-juniper were similar to those found in 

ponderosa pine forests but had relatively little in common with 

other forest habitats in the study area. The low degree of similarity 

to other forest habitats and high percentage of obligate and semiobligate species suggest that pinyon-juniper habitat contributes 

substantially to landscape-level avian diversity. These results are 

consistent with those of several other studies that found mature 

pinyon-juniper woodlands to be an important source of nongame 

wildlife habitat. 

Land managers often consider mature stands of pinyonjuniper to be undesirable, or at least less desirable, than 

earlier seral stages of this type, due to their lack of understory vegetation. Removal of trees through chaining or 

burning is often prescribed to produce more forage for big 

game and livestock, increase vegetative diversity, reduce 

erosion by stimulating growth of plants with high value for 

watershed protection, or prevent expansion of pinyon-juniper into adjacent grassland or shrub habitats. 

Decisions about which stands to treat, and how much 

acreage to treat, have most often been made on the basis of 

logistical constraints such as the presence of road access or 

sufficiently high fuel loads to carry a fire. Habitat values of 

the mature woodlands themselves receive little consideration, in part because they appear so extensive that there 

seems to be no possibility of exhausting the supply and in 

part because their arid nature and lack of vegetative diversity seem inconsistent with highly productive wildlife habitat. However, a number of studies have shown that pinyonjuniper woodlands support a wide array of nongame wildlife 

(Finch and Ruggiero 1993), and in some cases considerably 

greater numbers of species and individuals than the more 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Kathleen M. Paulin is a Wildlife Biologist with the Ashley National Forest, 

355 N. Vernal Avenue, Vernal, UT 84078. Sarah R. Dewey is a Biological 

Technician at the same address. During the study, Jeffrey J. Cook was a 

Biological Technician with the Wasatch/Cache National Forest, 8236 Federal 

Building, 125 S. State Street, Salt Lake City, UT 84138; current address is 300 

Fernhill Drive, DeBarry, FL 32713. 

240 

open habitats created through treatment (for example, Sieg 

1991; Sedgwick and Ryder 1987). 

The growing emphasis on ecosystem management requires that we design vegetative treatments within the 

context of a larger planning landscape. With this in mind, 

land managers must consider where to maintain mature 

pinyon-juniper stands for the values they provide, and 

where to treat to meet other objectives (Goodrich, these 

proceedings). This paper is intended to help managers make 

such decisions by describing the contribution pinyon-juniper habitats make to avian diversity in northeastern Utah 

landscapes. 

Study Area ________ _ 

The study was conducted in large stands of Utah juniper 

(Juniperus osteosperma) and Colorado pinyon pine (Pinus 

edulis) located within the Flaming Gorge National Recreation Area (NRA) in northeastern Utah. Sample sites were 

located on dry, rocky slopes at elevations ranging from 1,890 

to 1,980 m (6,200 to 6,500 ft). Trees were approximately 200 

to 400 years old, and there were few understory plants of any 

kind. Additional information on the pinyon-juniper portion 

of the study area can be found in a discussion of ecological 

units within the Green River corridor, Daggett County, 

Utah (Goodrich, these proceedings). 

Other forest habitats sampled were ponderosa pine (Pinus 

ponderosa), aspen (Populus tremuloides), Douglas fir 

(Pseudotsuga menziesii), lodgepole pine (Pinus contorta), 

spruce/fir (Picea engelmannii / Abies lasiocarpa), mixed lodgepole/spruce/fir, and riparian woodlands (dominated by cottonwood trees, but often mixed with one or more of the 

previously listed conifers). Sample sites for these forest 

habitats were on the Ashley National Forest, immediately 

west and south of the Flaming Gorge NRA. All sample sites 

were occupied by mature to old stands of trees. Elevation 

ranged from about 1,980 m (6,500 ft; ponderosa pine sites) to 

nearly 3,300 m (10,800 ft; spruce/fir sites). 

Methods 

Data in this paper were collected as part of the Ashley 

National Forest's breeding bird monitoring program. Methods were based on point count protocols found in Ralph and 

others (1993). We established 30 sample points in each of 

eight forest habitats common in the study area, with points 

divided among three distinct sites (stands) within each 

habitat. All points were located at least 100 m from any edge 

(change in cover type), and at least 200 m apart to avoid 

USDA Forest Service Proceedings RMRS-P-9. 1999 
double-counting birds. Each point was read twice during the 

1994 breeding season (mid-May through mid-July). Counts 

were begun within 15 minutes of sunrise and completed by 

10 a.m., to correspond with the period in which territorial 

males are most vocal. Bird detections (by sight, song or call) 

were recorded for 10 minutes at each point. All detections 

were recorded, regardless of distance from the observer. 

Results __________ _ 

Total individuals counted, total species detected and diversity index values for each forest habitat are shown in 

table 1. Not surprisingly, the riparian woodland sites ranked 

first in all three categories. Many studies have shown that 

riparian woodlands have higher vertebrate diversity than 

adjacent upland sites (Finch and Ruggiero 1993). Our results simply confirm the importance of riparian areas as 

wildlife habitat. 

Among the seven upland forest habitats, pinyon-juniper 

ranked second in total individuals and third in species 

richness and diversity. The variety and abundance of bird 

life in pinyon-juniper stands was comparable to that observed in Douglas fir, and considerably higher than in the 

lodgepole, spruce and fir stands that dominate much of the 

study area. In general, numbers of species and individuals 

tended to decrease with increasing elevation. 

The diversity index values followed a similar pattern, with 

the exception oflodgepole pine and Douglas-fir. The ShannonWeaver index is a function of both species richness and 

evenness (the distribution of individuals among the species 

present). A relatively species-poor habitat such as lodgepole 

pine can have a high diversity index ifthe indi vid uals coun ted 

are evenly distributed among all species present. Conversely, 

Douglas-fir bird communities tend to be dominated by a few 

abundant species. This causes it to have a lower index value 

than pinyon-juniper, despite having similar numbers of 

species and individuals. 

The total individuals counted and diversity indices in 

table 1 should be interpreted with caution. Bird densities in 

pinyon-juniper habitats are believed to be strongly influenced by juniper berry production, which can vary widely 

from year to year (Sieg 1991). Because we only have 1 year 

of bird data and did not make any estimates of berry 

production, we cannot say whether our results represent a 

peak or a low in bird numbers. We can say that pinyonjuniper is able to support a relatively high number and 

variety of birds, compared to other forest habitats in the 

study area, in at least some years. 

Land managers must consider more than simply the 

quantity of species each habitat contributes to a management landscape. A site that supports a few rare species can 

be as important as one that supports many common species 

when trying to maintain or enhance overall diversity. We 

attempted to characterize each habitat we sampled in terms 

of the uniqueness of its contribution to the landscape-level 

avian diversity, compared to other habitats in the study. One 

measure of uniqueness is the degree to which the various 

bird communities overlap with one another. Table 2 shows 

the results of pairwise comparisons using Sorenson's quotient of similarity (as described in Morrison and others 

1992). This quotient is based solely on the presence or 

absence of species, without consideration of abundance. The 

quotient varies from zero (no overlap) to one (identical 

species lists for each habitat). Pinyon-juniper shows relatively high overlap (0.658) with ponderosa pine, moderate 

Table 1-Total species detected, total individuals counted and Shannon-Weaver diversity index by habitat. 

Ponderosa Aspen Pinyon! Douglas Lodgepole Spruce! Mixed Riparian 

pine juniper fir pine fir conifer woodland 

Species detected 42 38 31 29 25 22 21 49 

Individuals counted 973 562 779 746 405 314 226 990 

Diversity index 1.26 1.20 1.19 1.09 1.18 1.08 1.04 1.28 

Table 2-Similarity of bird communities based on the proportion of species in commona. 

Ponderosa Aspen Pinyon! Douglas Lodgepole Spruce! Mixed Riparian 

pine juniper fir pine fir conifer woodland 

Ponderosa pine .575 .658 .676 .627 .469 .476 .462 

Aspen .575 1 .464 .627 .698 .567 .542 .598 

Pinyon/juniper .658 .464 1 .533 .429 .415 .385 .300 

Douglas-fir .676 .627 .533 .704 .627 .680 .385 

Lodgepole pine .627 .698 .429 .704 1 .638 .609 .405 

Spruce/fir .469 .567 .415 .627 .638 .791 .366 

Mixed conifer .476 .542 .385 .680 .609 .791 .371 

Riparian canyon .462 .598 .300 .385 .405 .366 .371 1 

Number of index values 

greater than 0.500 4 6 2 6 5 4 4 

aCalculated as Sorenson's quotient of similarity: OS = 2c/(a+b) where a = number of species in habitat a, b = number of species in habitat band C - number of species 

found in both habitats 

USDA Forest Service Proceedings RMRS-P-9. 1999 241 
Table 3-Proportion of each forest bird community comprised of obligate or semi-obligate species. a 

Ponderosa Aspen Pinyonl Douglas Lodgepole Sprucel Mixed Riparian 

pine juniper fir pine fir conifer woodland 

Percentage of 

obligate species 9.5 13.2 19.4 3.4 4.0 4.5 0 36.7 

Percentage of 

semi-obligate species 23.8 15.8 19.4 10.3 4.0 9.1 14.3 18.4 

Total obligates and 

semi-obligates 33.3 29.0 38.8 13.7 8.0 13.6 14.3 55.1 

aObligate: only detected in one forest type; semi-obligate: only detected in two forest types. 

overlap (0.533) with Douglas fir, and low overlap (less than 

0.500) with all other forest habitats. In contrast, each ofthe 

other upland forest habitats has moderate to high overlap 

with at least four other habitats. The mix of bird species 

found in pinyon-juniper appears to be uncommon within the 

study area. 

Another measure of uniqueness is the rarity ofthe species 

occurring within each habitat. Table 3 shows the percentage 

of species in each bird community that was restricted tojust 

one habitat (obligate species), or shared between only two 

habitats (semi-obligate species). Of the 31 species detected 

in pinyon-juniper habitat, 12 (38.8 percent) fit into one of 

these two categories. Only the riparian woodland sites had 

a higher percentage of obligate and semi-obligate species. 

Thus, not only is the particular combination of bird species 

found in pinyon-juniper habitats distinctive, a relatively 

high percentage of those species are rare or absent from the 

rest of the study area. 

Species we classified as pinyon-juniper obligates were 

ash -throated flycatcher (Myiarchus cinerascens), bl ue-gray 

gnatcatcher (Polioptila caerulea), Bullock's oriole (Icterus 

bullockii), pinyonjay (Gymnorhinus cyanocephalus), western scrub-jay (Aphelocoma coerulescens), and Virginia's 

warbler (Vermivora virginiae). Semi-obligate species that 

were most abundant in pinyon-juniper were juniper titmouse (Baeolophus ridgwayi),' gray flycatcher (Empidonax 

wrightii), and black-throated gray warbler (Dendroica 

nigrescens). Semi-obligates that were less abundant in 

pinyon-juniper than in their second habitat were spotted 

towhee (Pipilo maculatus), violet-green swallow 

(Tachycineta thalassina), and white-breasted nuthatch 

(Sitta carolinensis). Although we did not attempt to define 

an ecological basis for these apparent habitat preferences, 

our list agrees well with obligate and semi-obligate species 

lists published elsewhere (Fitton 1989; Cherry 1982) and 

probably does reflect the importance of some specific habitat features found in pinyon-juniper sites. 

Discussion ---------------------------------

Not surprisingly, we found pinyon-juniper bird communities to be different from those of most other forest habitats we sampled. Pinyon-juniper has obvious structural 

and vegetative differences from the tall pine, spruce, and fir 

forests of northeastern Utah's mountains, or from moist, 

highly productive aspen and cottonwood stands. But it may 

have surprised some to learn that the "pygmy forest," 

occupying poor sites and monotonously homogenous in its 

242 

composition and growth form, outranks many more stately 

forests in the abundance and variety of birds it supports. 

Designating some tracts of mature pinyon-juniper for retention is clearly a good investment for any manager 

interested in maintaining biodiversity on his or her management landscape. 

We compared bird communities from a variety of mature 

forests. However, the choice facing managers is rarely which 

forest to manage for on a given site. Most often, it is a 

question of which seral stage ofthe existing forest is desired. 

We did not sample early seral pinyon-juniper habitats, but 

we can offer some insights from other bird studies. Sedgwick 

and Ryder (1987) compared bird use of chained and unchained plots and found that chaining negatively affected 

abundance of cavity nesters, timber gleaners, aerial foragers, and species that foraged or nested in foliage. Birds that 

nested or foraged on the ground were found to use both 

treated and untreated plots, so in effect no group was 

benefitted by treatment. Likewise, Sieg (1991) found significantly higher bird numbers and species richness in pinyonjuniper woodlands than in adjacent grasslands. Both studies attributed the difference in bird use to the vertical 

structure of the woodlands, which provided niches not found 

in open habitats. 

This does not mean that pinyon-juniper treatments are 

always bad for birds. Cherry (1982) noted that slightly more 

bird species nested in late seral pinyon-juniper stands, but 

slightly more species foraged in early seral stands. This 

suggests that creating a mosaic of seral stages will provide 

the best balance of habitat features sought by birds. Sedgwick 

and Ryder (1987) indicated that shrub-dependent and edgeassociated species can benefit from well-designed pinyonjuniper treatments. They recommended selecting sites that 

have good potential for shrub growth, leaving lots of woody 

slash, designing treatment units with a high edge-to-interior ratio, and using a varying levels of treatment so that 

more trees are left standing toward the edges of units. All of 

these measures will add structural complexity to the treated 

unit, thus compensating in part for the loss of the pinyonjuniper overstory. Such treatment units will be more versatile as wildlife habitat than units stripped clean of wood and 

seeded with grasses. 

Although the discussion has so far focused on breeding 

season, managers may wish to consider habitat values at 

other times of the year. Sieg (1991) monitored bird use of 

pinyon-juniper throughout the year and found that it supported more birds in every season than the neighboring 

grasslands did. She speculated that the combination of 

readily available food (from cones and berries) coupled with 

USDA Forest Service Proceedings RMRS-P-9. 1999 
good thermal cover made it especially attractive to birds in 

the win ter. Cover val ues also make pinyon -j uni per a cri tical 

element of big game winter range (Davis, these proceedings). Again, a landscape mosaic that intersperses cover 

patches with openings providing foraging and browsing 

opportunities may be the best way to meet an array of 

management objectives. 

Conclusion ---------------------------------- Pinyon-juniper woodlands support a rich and distinctive 

bird community, which makes a substantial contribution to 

landscape-level avian diversity. Land managers should consider the habi ta t val ues of rna ture woodlands w hen planning 

pinyon-juniper removals to meet watershed and forage production objectives. The best management option will likely 

be a landscape that is thoughtfully designed to include 

functional patches of all seral stages. 

References ---------------------------------- Cherry, Marion B. 1982. The effects of pinyon-juniper chaining on 

wildlife of the Fillmore Ranger District, Fishlake National Forest. M.S. thesis. Logan, UT: Utah State University, Department 

of Range Science. 114 p. 

Davis, James N. These proceedings. The importance of pinyonjuniper woodland as big game critical winter range in Utah. In: 

Monsen, Stephen B.; Stevens, Richard; Tausch, Robin J.; Miller, 

Rick; Goodrich, Sherel, comps. 1998. Proceedings: ecology and 

USDA Forest Service Proceedings RMRS-P-9. 1999 

management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-OOO. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Research Station. 

Finch, Deborah M.; Ruggiero, L. F. 1993. Wildlife habitats and 

biological diversity in the Rocky Mountains and northern great 

plains. Natural Areas Journal. 13(3):191-203. 

Fitton, Sam. 1989. Nongame species accounts: the Utah juniper 

obligates. Lander, WY: Wyoming Game and Fish Department. 48 p. 

Goodrich, Sherel. These proceedings. Multiple use management 

based on diversity of capabilities and values within pinyonjuniper woodlands. In: Monsen, Stephen B.; Stevens, Richard; 

Tausch, Robin J.; Miller, Rick; Goodrich, Sherel, comps. 1998. 

Proceedings:ecology and management of pinyon-juniper communities within the Interior West; 1997 September 15-18; 

Provo, UT. Proc. RMRS-P-OOO. Ogden, UT: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Research Station. 

Morrison, Michael L.; Marcot, B. G.; Mannan, R W. 1992. Wildlifehabitat relationships: concepts and applications. Madison, WI: 

University of Wisconsin Press. 343 p. 

Ralph, C. J.; Geuppel, G. R; Pyle, P.; Martin, T. E.; DeSante, D. F. 

1993. Handbook of field methods for monitoring landbirds. Gen. 

Tech. Rep. PSW-GTR-144. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 41 p. 

Sedgwick, James A.; Ryder, R A. 1987. Effects of chaining pinyonjuniper on nongame wildlife. In: Everett, R L., compiler. Proceedings: pinyon-juniper conference. 1986 Jan. 13-16, Reno, NV. Gen. 

Tech. Rep. INT-GTR-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 581 p. 

Sieg, Carolyn H. 1991. Rocky Mountain juniper woodlands: yearround avian habitat. Research paper RM-296. Fort Collins, CO: 

U.s. Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station. 7 p. 

243 
Importance of Pinyon-Juniper Habitat to 

Birds 

Merrill Webb 

Abstract-Breeding bird surveys on seven sites in pinyon-juniper 

communities of Utah resulted in 53 total species. Blue-gray Gnatcatcher and Black-throated Gray Warbler were the only two species 

occurring on all seven transects. Of total species present 77 percent 

are considered neotropical migrants. Understory vegetation at each 

location appeared to be an important factor in determining bird 

species composition. 

The purpose of this study was to identify the species of 

birds using the pinyon and juniper forest habitat in Utah 

during the breeding season. An additional goal was to try 

to determine the numbers of each species. Although this 

effort was not funded by any government agency or private 

contributions this objective corresponds with the "Level I" 

monitoring described by the USDA Forest Service which 

"will allow practitioners to estimate the overall population 

trends of a variety of bird species within a forest. These 

monitoring efforts will help the USDA Forest Service meet 

its legal mandate to monitor populations of "indicators" of 

the broader vertebrate community" (Hutto 1994). 

Study Sites ________ _ 

Seven locations (fig. 1) were selected in the following 

Utah habitats and are listed by elevation, and from earliest 

count date to latest count date: 

1. Knoll Hollow, 5,900-6,400 ft, Spanish Fork Canyon, 

Utah County; July 7, 1995. . 

2. Oquirrh Mountains, 5,400-5,600 ft, north of Cedar 

Fort, Utah County; May 23, 1997. 

3. Beaver Dam Mountains, 4,400-4,900 ft, Washington 

County; May 27, 1997. The reason for selecting this site 

in southwestern Utah was to determine if there was a 

noticeable influence of Mojave Desert vegetation on the 

avifauna. 

4. Foothills on east side of Stansbury Mountains near 

South Willow Canyon, 5,720-6,560 ft, Tooele County; 

June 19, 1997. 

5. Dove Creek area, 6,000-6,100 ft, Box Elder County; 

June 20, 1997. Purpose in selecting this site in northwestern Utah was to determine if species composition 

was similar to other Great Basin habitats that had been 

previously sampled. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Merrill Webb teaches at Provo High School, Provo, UT. 

244 

6. Long Ridge, west of Nephi, 5,900-6,200 ft, Juab 

County; June 27, 1997. Dog Valley to the west had suffered 

a serious fire the previous summer. The reason for selecting 

this location was to determine if bird species had been 

concentrated on this unburned ridge as a result of habitat 

lost to fire on either side. 

7. Foothills at the base of the Wasatch Plateau, 6,600-

7,000 ft, southeast of Spring City, Sanpete County: 

July 1, 1997. This was a thickly wooded area of pinyon 

and juniper. I felt that it was important to determine if 

species composition was as similar at the Colorado PlateauGreat Basin interface as it was at the other locations. 

Elevations for this study ranged between 4,400 ft at the 

Beaver Dam Mountain site to 7,000 ft at the Wasatch 

Plateau site near Spring City. 

Methods 

Study sites in suitable habitat were randomly selected 

and determined by accessibility. Protocol called for each 

transect to be 2 miles long. Each of the 10 sampling 

points was positioned at 0.2 mile intervals (Hutto 1994). 

Figure 1-Location of the seven Utah study sites. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Following the protocol (Hutto 1994), transects were established at sites with minimal disturbance. Two of the 

transects were conducted on tertiary roads where vehicle 

noise was at a minimum; five of the transects were walked 

using compass headings to maintain as straight a line as 

possible. As determined by protocol 10 minutes was the 

time allocated at each point during which birds were 

identified by sight, sound or a combination of both (National 

Geographical Society 1987). Binoculars (8 x 30) were used in 

making identification of observed birds. Birds farther than 

50 yd away on either side of the transect line were not 

counted. Birds detected flying over the plot rather than 

detected from within the vegetation were recorded separately and were not listed as part of the vegetation avifauna. Counts began immediately upon arrival at the 

census station. No attracting devices or records of calls 

were used. 

Counts started after the predawn chorus was over (between 6:30 and 7:00 a.m.) and concluded by 10:30 a.m. This 

corresponds with the period of time during which bird 

activity and song is more-or-Iess constant. It was important to not record a bird more than once at each interval 

point. If a bird was flushed during the move from one 

interval point to the next it was not included in the totals. 

Results __________ _ 

As a result of sampling seven separate sites, a total of 

53 species were identified (table 1). The Blue-gray Gnatcatcher and Black-throated Gray Warbler were the only 

two species that occurred on all seven transects. However, Mourning Dove, Juniper (formerly Plain) Titmouse, 

Spotted (formerly Rufous-sided) Towhee and Chipping 

Sparrow occurred on six of the seven transects (table 2). 

There were 22 species that occurred only once on any of 

the seven transects (table 3). In terms of total numbers for 

all seven transects the Mourning Dove was the most abundant species (table 2). The Oquirrh mountain transect had 

the highest number of total bird species with 27 followed 

closely by Knoll Hollow in Spanish Fork Canyon with 26 

(table 1). 

Of the 53 total species listed on the seven transects 41 

are considered neotropical migrants (table 4). By definition 

neotropical migrants are birds that spend their summers in 

Canada and the United States and their winters in Mexico, 

the Caribbean, Central America, and South America (the 

region known as the New World tropics, or neotropics). 

Although the name "neotropical migrant" sounds exotic, 

we're actually talking about common birds, and lots of 

them-at least 250 species, nearly one-third of the birds 

that breed in North America (Line 1993). 

Discussion --------------------------------- A total of 53 bird species were identified on seven 

pinyon-juniper transects (table 1). In most cases the type of 

shrub understory appeared to influence species diversity. 

For example the Virginia's Warbler occurred on only 

three transects. The two locations with the most sightings, 

both n = 7, had heavy concentrations of Gambel's oak. At 

the other locations, there was only one sighting. The only 

USDA Forest Service Proceedings RMRS-P-9. 1999 

transect where Brewer's Sparrow, a characteristic sagebrush inhabitant (Ryser 1985), occurred, was in the Dove 

Creek area where sagebrush was the dominant understory 

species. The Black-throated and Black-chinned Sparrows 

were found only in southwestern Utah at the Beaver Dam 

Mountain site in association with an understory of 

blackbrush, cliff rose, and yucca. Based on my observations, 

the Black-chinned Sparrow is more of a seasonal resident 

of Mojave Desert upland shrub communities whereas the 

Black-throated Sparrow is more of a seasonal resident of 

both the Mojave and Great Basin Deserts. The Beaver Dam 

Mountain site is, in fact, a vegetational ecotone between the 

Mojave and Great Basin Deserts (Holmgren 1972) so it is 

not surprising to find both of these sparrows in residence. 

The Spanish Fork Canyon transect was completed in the 

summer of 1995 while I was conducting neotropical bird 

surveys for the USDA Forest Service on the Uinta National 

Forest. The site had been identified as a possible chaining 

area. This location harbored stands of very large pinyon 

pine and juniper trees, the most mature of any of the 

transects I studied. Sometime after the survey was conducted the decision was made to not chain the area. As it 

turned out this site was the second most productive of all 

seven transects. On this transect there were only six points 

on which totals were obtained instead of the usual ten 

because the vegetation over the brow of the hill where the 

additional four stops would have occurred was all Gambel's 

oak. Therefore, I believe, this particular example indicates 

the importance of obtaining bird species composition and 

numbers before conducting chaining operations that would 

seriously impact breeding birds dependant on this type of 

habitat. 

The most productive site was the Oquirrh Mountain site. 

I believe that the high number of bird species there is a 

reflection of the layered canopy. This site had more structural diversity than any of the other sites. 

The area surrounding the Long Ridge site had recently 

burned prompting a working hypothesis that this location 

might be a refugia for displaced breeding birds. The data 

confirm this hypothesis inasmuch as Mourning Dove (n = 

16), Gray Flycatcher (n = 10), Juniper Titmouse (n = 10), 

Bewick's Wren (n = 12), Blue-gray Gnatcatcher (n = 7), 

Solitary Vireo (n = 6), Spotted Towhee (n = 12), Brownheaded Cowbird (n = 9), and House Finch (n = 13) were at 

their highest numbers at this site (table 1). 

Of the 53 bird species documented to occur in the 

pinyon-juniper stands of this study, 41 of them are considered to be neotropical migrants (table 4). Data indicate 

that the pinyon-juniper forests provide important habitat 

for at least nine of these neotropical migrants (table 2). 

Food, cover, and nesting are three essential requirements 

provided by this important community type. 

In summary, I discovered that the pinyon-juniper forest 

supported a greater variety of bird species than I had 

anticipated based on my limited experience in birding this 

type of habitat. But the total number of species depending 

entirely on this type of habitat for breeding purposes is low 

compared to other types of habitat in the state. The results 

verify the importance of the pinyon-juniper forest to the 

continued breeding success of the Blue-gray Gnatcatcher, 

the Black-throated Gray Warbler and the Gray Flycatcher, 

all of which are neotropical migrants. 

245 
Table 1-Bird species by transect (see appendix for mnemonic bird species code). 

Beaver Dam Spanish Fork 

Oquirrh Mountain Stansbury Dove Creek Long Ridge Spring City Canyon 

COHA 

RTHA 2 

GOEA 

AMKE 

MODO 9 5 10 5 16 10 

CONI 2 

BLTH 2 

RSFL 5 

GRFL 4 9 10 10 8 

COFL 2 

ATFL 2 2 3 

SCJA 8 5 2 5 

CLNU 

PIJA 2 

BBMA 2 12 

CORA 5 4 1 

MOCH 5 

UNCH 

RBNU 

WBNU 4 

PLTI 5 3 2 10 3 

ROWR 1 

BEWR 1 4 12 

HOWR 1 

BGGN 2 5 7 3 1 

MOBL 3 2 3 

TOSO 4 

HETH 1 

AMRO 7 2 9 2 

SATH 5 

NOMO 

GRVI 11 

SOVI 1 2 2 6 5 

WAVI 5 1 

VIWA 7 7 

BTYW 2 4 3 5 4 

WETA 4 8 6 2 

BHGR 6 3 1 1 

LAZB 3 

GTTO 3 9 

RSTO 5 8 6 12 5 

BCSP 4 

CHSP 7 15 4 8 8 9 

BRES 29 

LASP 

BTSP 6 

WEME 2 

BRBL 3 

BHCO 2 2 2 9 

SCOR 

CAFI 

HOFI 8 13 10 

PISI 4 7 

Total 27 14 17 20 17 18 26 

246 USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 2-Twelve bird species with highest total numbers on seven transects 

(see appendix for mnemonic bird species code). 

Pneumonic Bird species Number # of Locations 

MODO Mourning Dove* 55 6 

CHSP Chipping Sparrow* 51 6 

GRYF Gray Flycatcher* 41 5 

RSTO Rufous-sided Towhee * 37 6 

HOFI House Finch 32 4 

BRES Brewer's Sparrow* 29 1 

PLTI Plain Titmouse 24 6 

SCJA Scrub Jay 21 5 

AMRO American Robin* 21 5 

WETA Western Tanager* 21 5 

BGGN Blue-gray Gnatcatcher* 20 7 

BTYW Black-throated Gray Warbler* 20 7 

*Neotropical Migrant 

Table 3-Species occurring only once, listed by transect (see appendix for mnemonic bird species code). 

Spanish Beaver Dam 

Fork Oquirrhs Mountain Stansbury Dove Creek Long Ridge Spring City 

CLNU GOEA NOMO AMKE BRES COHA 

RBNU BLTH GRVI BRBL ROWR 

WBNU PIJA BCSP 

TOSO HOWR BTSP 

HETH LASP SCOR 

LAZB CAFI 

Table 4-Neotropical species occurring in the pinyon-juniper forests of Utah 

(see appendix for mnemonic bird species code). 

1. COHA 11. ATFL 

2. RTHA 12. ROWR 

3. GOEA 13. HOWR 

4. AMKE 14. BGGN 

5. MODO 15. MOBL 

6. CONI 16. TOSO 

7. BLTH 17. HETH 

8. RSFL 18. AMRO 

9. GRYF 19. SATH 

10. COFL 20. NOMO 

Studies should be conducted during the winter to determine the importance of pinyon-juniper habitats to the survival of wintering bird species. 

Acknowledgments 

I appreciate Dea Nelson and Dave Stricklin of the 

Unita National Forest for funding a 3 year neotropical 

bird study that provided the background and impetus for 

the current study. I thank my Provo High School colleague, 

Doyle Nielson, for providing technical assistance. I also 

thank my friend, Durant McArthur, for some helpful suggestions and technical assistance. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

21. GRVI 31. BCSP 

22. SOVI 32. CHSP 

23. WAVI 33. BRES 

24. VIWA 34. LASP 

25. BTYW 35. BTSP 

26. WETA 36. WEME 

27. BHGR 37. BRBL 

28. LAZB 38. BHCO 

29. GTTO 39. SCOR 

30. RSTO 40. CAFI 

41. PISI 

References __________________ __ 

American Ornithologists' Union. 1995. Fortieth supplement to the 

American Ornithologists' Union Check-list of North American 

Birds. The Auk 106: 819-830. 

Holmgren, N. H. 1972. Plant geography of the intermountain 

region. In Cronquist, A.; Holmgren, A. H.; Holmgren, N. H.; 

Reveal, J. L. Intermountain flora, Hafner Publishing Company, 

Vol. 1: 77-159. 

Hutto, R. L. 1994. Field methods for landbird monitoring projects, 

USFS Region 1 contract #53-0343-2-00207.9 p. + 5 appendixes. 

Typescript manuscript on file at the Uinta National Forest 

Supervisors' Office, Provo, Utah. 

Line, L. 1993. Silence of the songbirds. National Geographic 183(6): 

68-91. 

National Geographic Society. 1987. National Geographic Society 

field guide to the birds of North America. 2nd ed. 464 p. Washington, D. C.: National Geographic Society. 

Ryser, F. A., Jr. 1985. Birds of the Great Basin. Reno, NV: University of Nevada Press. 604 p. 

247 
Appendix-Four-Ietter mnemonic bird codes of all birds encountered in 

thisstudy ________________________________________________ ___ 

Code Standard bird names Code Standard bird names 

COHA Cooper's Hawk HETH Hermit Thrush 

RTHA Red-tailed Hawk AMRO American Robin 

GOEA Golden Eagle SATH Sage Thrasher 

AMKE American Kestrel NOMO Northern Mockingbird 

MODO Mourning Dove GRVI Gray Vireo 

CONI Common Nighthawk SOVI Solitary Vireo 

BLTH Broad-tailed Hummingbird WAVI Warbling Vireo 

RSFL Red-shafted Flicker VIWA Virginia's Warbler 

GRFL Gray Flycatcher BTYW Black-throated Gray Warbler 

COFL Cordilleran Flycatcher WETA Western Tanager 

ATFL Ash-throated Flycatcher BHGR Black-headed Grosbeak 

SCJA Scrub Jay LAZB Lazuli Bunting 

CLNU Clark's Nutcracker GTTO Green-tailed Towhee 

PIJA Pinyon Jay RSTO Rufous-sided Towheea 

BBMA Black-billed Magpie BCSP Black-chinned Sparrow 

CORA Common Raven CHSP Chipping Sparrow 

MOCH Mountain Chickadee BRES Brewer's Sparrow 

UNCH Unknown Chickadee LASP Lark Sparrow 

RBNU Red-breasted Nuthatch BTSP Black-throated sparrow 

WBNU White-breasted Nuthatch WEME Western Meadowlark 

PLTI Plain Titmousea BRBL Brewer's Blackbird 

ROWR Rock Wren BHCO Brown-headed Cowbird 

BEWR Bewick's Wren SCOR Scott's Oriole 

HOWR House Wren CAFI Cassin's Finch 

BGGN Blue-gray Gnatcatcher HOFI House Finch 

MOBL Mountain Bluebird PISI Pine Siskin 

TOSO Townsend's Solitaire 

a New name for the Plain Titmouse is Juniper Titmouse and new name for the Rufous-sided Towhee 

is Spotted Towhee (American Ornithologists' Union 1995. 

248 USDA Forest Service Proceedings RMRS-P-9. 1999 
Role of Pinyon-Juniper Woodlands in 

Aboriginal Societies of the Desert West 

Joel C. Janetski 

Abstract-Archaeological data and ethnographic accounts testify 

of the importance of resources available in the pinyon-juniper 

woodland to native peoples since the early Holocene. Food, shelter, 

raw material for tool construction, tinder, and preferred settlement location are a few of these. Although early evidence is 

sometimes inconclusive, information from more recent periods 

argue for increasing reliance on this vegetative community and its 

resources through time. 

The pinyon and juniper community is widespread across 

the Colorado Plateau and Great Basin regions ofthe Desert 

West. This community provided aboriginal peoples with 

some of the most basic raw material to sustain life. The 

intent of this paper is to review some of the ways these 

resources were used in recent times as well as the evidence for use in the more distant past. I will focus on 

plants in the paper, and more specifically, pinyon and 

juniper. Clearly many other resources (animals of various kinds, grasses, sage) were present, but a discussion 

of all such resources and the ways in which they were 

used would take me far beyond the allotted time. 

Aboriginal Peoples of the 

Desert West 

The Desert West was and is home to various Shoshone (or 

Uto-Aztekanspeaking) groups, Ute, Southern Paiute, Northern Paiute, Kawaiisu, and W~sho (Hokan speaking) in the 

Great Basin and Colorado Plateau and the Puebloan (Hopi, 

Zuni, Rio Grande Pueblos) and Athabaskan (Navaho and 

Apache) peoples of Arizona and New Mexico. Lifeways in 

these diverse regions were likewise variable. Nearly all of 

the peoples of the Great Basin, for example, were hunters 

and gatherers and relied exclusively on indigenous plants 

and animals for their livelihood. Exception were the Southern Paiute in the St. George Basin who raised some crops: 

corn, squash, maybe some others. Of course, the Puebloan 

peoples were farmers but, nonetheless, gathered many 

native or wild resources both for food and for other purposes. The Navaho and Apache, recent migrants to the 

American Southwest, are more eclectic in their subsistence 

practices, with pastoralism mixed with some farming and 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Joel C. Janetski is with the Department of Anthropology, Brigham Young 

University, Provo, UT. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

gathering and hunting. The pinyon-juniper community 

provided important resources for all. 

Ethnographic Uses of Pinyon 

and Juniper 

Food 

Nuts from pinyon pine, both Pinus edulis (Colorado 

pinyon) and P. monophylla (singleleaf pinyon), were one of 

the most important foods for peoples of the Great Basin and 

Colorado Plateau. Wherever they were available they were 

gathered in large quantities. But they were particularly 

important to the Great Basin people. Premier Great Basin 

ethnographer, Julian Steward, calls pinyon "The most 

important single food species where it occurs ... " (Steward 

1938:27). 

Pine nuts are high in protein and fats, although the 

percentages vary with the species (table 1). Singleleaf 

pinyon is higher in fat and protein while Colorado pinyon is 

higher in carbohydrates. The fat content exceeds that of 

chocolate and both contain all 20 amino acids required for 

human growth. Also, both contain tryptophan, an essential 

amino acid that is deficient in the diet of corn farmers 

CHuckell 1992:125). Singleleaf produces somewhat fewer 

seeds than Colorado, a tendency that is offset by the thinner 

hulls of singleleaf resulting in larger nutmeats. Both are 

ranked high on the list of available foods for people in the 

arid west. That is, pine nuts yield excellent returns for 

people who gathered wild foods for a living. 

Productivity of the trees varies also. Good crops for a 

particular tree can occur every 4 or 5 years for P. edulis and 

every 2 or 3 for P. monophylla, although some nuts may be 

produced every year. Steward (1938:27) states: "In some 

years there is a good crop throughout the area, in some 

years virtually none." Productivity also apparently varies 

with the age of the stand, with old trees producing fewer 

filled hulls CHuckell1992:132). An illustration of this variability is presented by Lanner (1983:170) for a stand of 

mOllophylla in the Raft River Mountains of northwestern 

Utah. A 5 year study reported per acre cone production as 

follows: 1975, 765 cones; 1976, 0 cones; 1977, 2,560 cones; 

1978,2,325 cones; 1979,585 cones. In general, singleleaf is 

more prod uctive and more predictable than Colorado pinyon (Sutton 1984). Sullivan (1992:200-201), on the other 

hand, has argued that archaeologists have tended to overplay the variable nature of pinyon nut production. Citing 

various sources, he maintains that pinyon production can 

be predicted rather accurately 2 years in advance and with 

considerable accuracy 1year in advance (Sullivan 1992:200). 

Gathering of Pine Nuts-Pine nuts were usually gathered in the early fall at about the time ofthe first frosts. Two 

249 
Table 1-Nutritional values of P. edulis and P. monophylla (kernels only-percentages by weight) 

(from Madsen 1986). 

Species Water Protein Fat Crude fiber Carbohydrate Ash Call100 gm 

P. edulis 

P. monophylla 

3.0 

10.2 

14.3 

9.5 

60.9 

23.0 

methods were employed: green or brown cone harvesting 

(see Madsen 1986). The former took place before the cones 

opened. The green cones were either removed from branches 

using a hook or sometimes branches containing cones were 

broken off the tree. Once removed the sticky cones were 

placed in pits and roasted until the cones began to open. 

They were then pulled out ofthe fire with sticks, cooled, and 

opened, and the nuts were removed and tossed in a heap. 

A graphic account of pine nut harvesting by the green 

cone method is suppled by Howard Egan in western Nevada 

in the late 1800's. 

Jack and I were taking a scouting trip high up in the Schell 

Creek Range of mountains, when we came across an Indian 

who, with his [wife) and children were busily engaged 

gathering pine nuts. The man had a long pole with a strong 

hook fastened to one end. He would reach up in the tree to 

the pine cones, hook the crook around the branch on which 

they hung and pull branch and all down, the woman and 

children carrying them to a place and piling them up in a 

heap. When they had collected as many as they wanted that 

day, the [man) has finished his part of the work and could 

pass the rest of the time sleeping or hunting squirrels just 

as he pleased. 

The women and children gathered a little dry brush which 

was thrown loosely over the pile of cones and set fire to. The 

cones are thickly covered all over with pitch, for this reason 

they make a hot fire, the [woman) watching and stirring it 

up as needed to keep the nuts from burning, as she rakes 

them back from the fire as a man would do when drawing 

charcoal. 

When the pitch was all burned off the burs or cones, the 

[woman) spreads a blanket down close to the pile, then 

taking up one cone at a time, would press them end ways 

between her hands, which opens the leaves, under which 

there were two nuts to every leaf, Then shaking the cones 

over the blanket area the nuts would all fall out as clean as 

you please. 

When the nuts had all been cleaned from the cones they 

were put in a large basket that would hold over two bushels 

and was nearly; full, the [woman) carrying that on her back 

to a place where they were placed all through the pine-nut 

grove to save carrying them too far and save time for the 

harvest does not last long, for a heavy frost will cause the 

cones to open and the nuts to fall to the ground (Egan 

1917:241). 

The brown cone method was practiced after the cones 

began to open on the tree. Large woven mats (or in recent 

times canvas tarps) were placed under the tree. The harvesters beat on the branches holding cones with long sticks 

to either knock the nuts out of the cones or the cones out of 

the tree. Both would then fall on to the mats. The cones and 

nuts were gathered and placed in large conical baskets for 

transport. 

250 

1.1 

1.1 

18.1 

53.8 

2.7 

2.4 

714 

488 

Of course, once nuts fell to the ground oreven when cones 

had opened while still on the tree, they were eagerly sought 

by other foragers (birds, squirrels, insects). 

Pine Nut Processing-Pine nut meats were eaten raw 

while harvesting or after toasting. But most were toasted, 

hulled, winnowed, and ground into a paste for making a 

pine nut soup or gruel. Initial roasting was done by placing 

a few handfuls of nuts on a winnowing tray along with hot 

coals. The two were mingled while moving the tray quickly 

to keep it and the nuts from burning. The coals were then 

tossed off the tray and the nuts placed on a flat rock and 

lightly crushed to crack the hulls. The cracked nuts were 

then returned to the winnowing tray and separated from 

the meats by tossing all into the air with the lighter hulls 

blown away by the wind. The meats were then toasted 

again in a similar fashion until the nuts were hard. After 

cleaning the meats with a nut paste, they were ground into 

flour on the grinding stones. The flour was used to make 

soup or gruel. The soup was sometimes mixed with meat to 

give it more flavor. The Navajo made a kind of pine nutbutter and spread it on corn cakes. 

Pine Nut Storage-Importantly, pine nuts could be 

stored for future use. Pits or other storage facilities were up 

to 5 ft in diameter, lined with rocks, grass, or bark (probably 

juniper) and covered over with more bark, branches, dirt, 

and more rocks. Nuts were sometimes stored in cones and 

sometimes in hulls. Stored in this way, nuts lasted at least 

through the winter. Puebloan peoples would store enough 

pine nuts to last them 2 or 3 years. Great Basin tribes 

usually consumed all their stores by the late winter. 

The importance of pinyon is reflected in myths and the 

fact that some groves were actually owned by families and 

defended (Steward 1933). In Owens Valley, California, for 

example, feuds were sometimes fought over the gathering 

of pine nuts in neighbors groves. 

Juniper (Juniperus spp.) berries were occasionally used 

for food but had much less value as a food item than pinyon. 

The Apache ate them fresh and pounded them to make 

bread or a juniper tea (Goodwin 1935). Utes separated the 

berry pulp from the seed with a stone muller after which the 

pulp was eaten fresh or dried (Smith 1974). Harrington 

(1967) describes juniper berries used by Southwest people 

as an ingredient in bread or in stews for flavoring. Great 

Basin people used juniper berries sparingly, a fact suggested 

by the Shoshone term for Juniper, wa'ap 0 pi, which means 

fire material or kindling wood according to Chamberlin 

(1911:372), which emphasizes a nonfood role for juniper. 

Providing raw material for fuel and constructing shelters 

were the two most important uses for juniper (see below). 

However, juniper berries were occasionally eaten in fall 

and winter after boiling (Fowler 1986:73). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Shelter and Other Constructions 

Pinyon and juniper were the primary materials for house 

construction among many peoples of the Desert West. 

Although Puebloan house walls were constructed of stone, 

the roofs of both residential and religious architecture 

(kivas) were constructed using pinyon and/or juniper for 

beams and held up with timbers of the same material. The 

more nomadic Navajo built hogans, sweathouses, ramadas, 

fences and corrals, drying racks, and storage facilities 

using primarily juniper and pinyon as raw material (Jett 

and Spencer 1981). Not only were the trunks of trees used 

for wall construction and roofsupport, but juniper bark was 

an integral element in roof construction. 

Stansbury made numerous observations ofN ative American lifeways as he traversed the perimeter ofthe Great Salt 

Lake in 1852. At the north end of the lake he described a 

house built using juniper: 

In a nook of mountains, some Indian lodges were seen, 

which had apparently been finished but a short time. They 

were constructed in the usual form, of cedar (juniper) poles 

and logs of considerable size, thatched with bark and 

branches, and were quite warm and comfortable. The odor 

of the cedar was sweet and refreshing. Such houses were 

often floored with mats of juniper loosely woven 

(Stansbury 1852: 111). 

Medicinal and Miscellaneous Uses 

Medicinal uses of pinyon were limited, although pitch or 

gum was sometimes put into boiling water and drunk to 

purge individuals infected with worms or other parasites 

(Chamberlin 1911:350). Juniper brewed into a tea furnished 

medicine for coughs and colds (Chamberlin 1911:372). 

Pinyon pitch was used to line basketry water jugs and to 

seal and glue ceramic vessels together. Pitch also served as 

a mastic to hold projectile points or stone tools tightly to a 

shaft or handle. Juniper bark provided an important fiber 

for mats, diapers, menstrual pads, fire making material 

(hearth and tinder) as well as a cushioning and protective 

lining for storage pits. Open twined matting of juniper 

bark was a common textile manufactured by Great Basin 

peoples. The ubiquitous use of both woods for fuel across 

the Desert West seems an obvious point. 

Pinyon Ecology and Shoshonean 

Settlement 

The variability in pine nut productivity was a critical factor 

in Great Basin aboriginal life. As the pinyon harvest went, so 

went the people. As noted earlier, pine nuts are produced 

every year but only produce quantities adequate to supply 

stores for winter food demands every few years. Because of 

this variation in productivity and the need to spend the winter 

near stores or cached nuts, Julian Steward proposed a causal 

relationship between the unpredictability of pinyon and the 

high residential mobility of these peoples as they moved 

winter villages to be near the most recent productive areas. 

This fact, according to Steward, contributed to the fragmentation of aboriginal society in the Great Basin (especially the 

Western Shoshone in the central portion of the region). 

USDA Forest Service Proceedings RMRS-P-9. 1999 

The extreme importance placed on pinyon by Steward 

made life without pinyon a difficult one to understand for 

people in the Great Basin area. Given the nutritional value 

and the availability of pinyon, one would expect that pine 

nuts would be in the diet of native peoples as long as they 

were available in good numbers. In addition, the presence 

of pinyon in archaeological sites provided a basis for assuming a lifeway in the past similar to that documented by 

Steward. How long ago did pinyon appear in archaeological 

sites? The presence of pinyon in archaeological sites could 

argue that the nomadic lifeway described by Steward for 

the Western Shoshone was operative at the time the site 

was occupied. This leads to a more complex question of 

what kinds of archaeological evidences are there for the use 

of pinyon? This task proves more difficult than it might 

seem. A review of the evidence for the use of pinyon in the 

Desert West follows. 

Archaeological Evidences 

Archaeological excavations in Utah and elsewhere in the 

Desert West have demonstrated the importance of both 

pinyon and juniper for food, construction materials, and 

fibers. Demonstrating the use of either plant for medicinal 

use is difficult given the vagaries of archaeological data. 

The following is an attempt to synthesize far flung data but 

is not an attempt to be exhaustive. 

Food 

Proving that pine nuts were used for food is sometimes 

difficult. One must first ask what is acceptable evidence of 

using pine nuts for food. Certainly the most direct evidence 

of pinyon use would be finding pinyon remains in human 

feces or coprolites or in garbage dumps (middens) left by 

humans. Of course pinyon nut meats do not preserve, so 

typically the evidence consists of hull fragments. But just 

finding nut hulls in sites is not positive proof of dietary use 

since there is always some questions as to how they arrived 

in the site. Many critters gather, store, and eat pinyon so 

one has to be cautious in drawing conclusions. Charred 

hulls are generally accepted as good evidence for humans 

gathering and consuming nuts. 

Indirect evidence of pinyon use would include grinding 

stones used for processing pine nuts. Unfortunately, nearly 

all hard seeds (which were an important part of the diet in 

the Basin) were also processed in much the same way. It is 

the case, however, that grinding stones show up early in the 

sequence at the large cave sites around the Great Salt Lake 

(Danger and Hogup Caves, for example). 

Locations of sites in the pinyon-juniper community is 

also indirect evidence of pinyon use given the tendency for 

people to camp in such areas near caches. But, they could 

also simply be there for the wood, to get up and out of the 

colder valley bottoms, or to be close to snow fields for water. 

The presence of stone circles like those described for storage 

facilities would also argue for pine nut use and storage. 

These are present in the pinyon-juniper community in the 

Great Basin. Few have been excavated, however. 

Interestingly, unequivocal use of pine nuts for food is 

somewhat scarce in the archaeological record, especially 

251 
prior to about 1,500 or 2,000 years ago. Earliest evidence of 

human use of pinyon (most likely P. edulis) comes from 

heavily used dry caves in the Great Basin and the Northern 

Colorado Plateau. In sites such as Old Man Shelter, Atlatl 

Cave, and Dust Devil Cave (all in southeastern Utah), 

pinyon is present in the deepest deposits dated to as early 

as 8,000 years ago (Coulam and Sharpe 1993; Van Ness 

1986). On the Colorado Plateau near the juncture of the 

Green and Colorado Rivers, pinyon appears in quantities in 

Cowboy Cave by 3,500 years ago (Hewitt 1980:135). Interestingly, the evidence at Cowboy Cave is in the form of pitch 

on basketry items, spindle whorls, and projectile points as 

well as nuts and needles. Juniperus osteosperma (twigs and 

seeds) and Pinus edulis (leaves and seeds) were both present 

in the deepest layers at Cowboy Cave, although these levels 

contain no clear evidence of human occupation. These 

botanical remains demonstrate that pinyon and juniper 

was present in this portion of the Colorado Plateau by 

11,000 years ago (Jennings 1980:19,170). 

The earliest dates for pinyon use in the Great Basin come 

from Danger Cave near Wendover, Utah, well to the north 

of the dry caves of the Northern Colorado Plateau. Madsen 

and Rhode (1990) have dated pine seed coats from Danger 

Cave to -7,410 years ago, although this hull is apparently 

from limber pine (P. flexilis) rather than pinyon (Rhode and 

Madsen 1997). Pinyon pine is definitely present at Danger 

Cave by 6,800 years ago, however. Rhode and Madsen 

(1997:17) conclude that pine nuts were a part of the diet 

from the onset of human use of Danger Cave despite the 

probability that the closest groves of ei ther limber or pinyon 

pine were at least 25 km to the west. These conclusions are 

supported in part by finds at Bonneville Estates Cave, just 

south of Wendover, where pine nuts (apparently pinyon) in 

good quantities were recovered from levels dated to 6,000 

BP (Schroedl 1997). In GatecliffShelter in Monitor Valley, 

central Nevada, charred cones and twigs document the 

presence of pinyon in that area by 5,300 years ago and seeds 

and seed coat fragments are present just slightly later, 

about 5,200 years ago (Thomas 1983:153,174). 

Madsen (1986) has argued that a strong case for an 

important dietary role for pinyon during these early times 

is lacking (Madsen 1986). The best evidence for heavy use 

of pinyon in the Great Basin comes from Crab Cave near the 

Fish Springs waterfowl refuge where thousands of hulls 

were found in deposits dating to sometime after 2,000 years 

ago (Madsen 1979). Interestingly, the closest source of pine 

nuts for Crab Cave inhabitants is the Deep Creek Mountains that are at least 35 km away. In Kachina Cave on the 

Utah-Nevada border, two caches dated to 1,350 years ago 

also yielded large quantities of pine nut hulls, although 

here pinyon groves are nearby. 

In the extreme western Great Basin in Owens Valley of 

eastern California, archaeologists have found that evidence for intensive use of pinyon does not appear until after 

about AD 600 or so (Bettinger 1989). Later sites, such as 

Pinyon House located in the pinyon-juniper community in 

the White Mountains, contained all the evidences one 

might expect of heavy pinyon use: hulls, mulIers, cache pits, 

roasting pits for cones, pinyon hooks, and bedrock mortars. 

This kind of strong evidence for pinyon exploitation is 

lacking at earlier sites, although there is evidence of pinyon 

being present in Owens Valley even earlier than that at 

252 

Danger Cave. Reynolds (1997:3) reports dates of 8,790 ± 

110 BP and 7,880 ± 60 PB from pack rat middens at the 

north and south end of the White Mountains, for example. 

None of these dates are from cultural contexts, however, 

and no evidence exists for human reliance on pinyon prior 

to the AD 600 date proffered above. 

Explanations vary as to why pine nuts don't seem to be 

used abundantly until the Late Holocene in the Great 

Basin. Perhaps pinyon only recently migrated into areas 

such as Owens Valley. Or, perhaps higher ranked foods 

were more abundant early, making pinyon less attractive. 

It is also possible that our sample is simply not an accurate 

representation of past diet. 

Also somewhat puzzling is the variability in the evidence 

for pinyon use at Anasazi sites often located in dense 

pinyon-juniper woodlands. Rohn 1971, for example, reports 

few evidences of pinyon use at Mug House at Mesa Verde. 

It is possible, however, that this scarcity is a function of not 

looking very closely for plant remains. More recent archaeological reports, such as those from the Grand Canyon 

area (Sullivan 1992), contain good evidence for pinyon use 

by Anasazi between AD 800 and AD 1200. In fact, Sullivan 

found evidence that pinyon and other wild plants (amaranth and chenopod seeds, cactus, grasses) could have been 

more important than corn. Likewise, Huckell (1992) reports abundant pinyon remains (seeds, seed shells, cone 

scales) from Anasazi sites just south of the Grand Canyon. 

Pinyon was also common in Antelope Cave north of the 

Grand Canyon on the Uinkaret Plateau in levels dated to 

the Anasazi occupation (AD 700-900) (Janetski and Hall 

1983). Antelope Cave is currently 10 to 15 km from the 

nearest pinyon groves, suggesting that people were transporting pine nuts to the site. At the nearby Pine Nut Site, 

however, only a few charred needles were found in the 

float samples despite the site name. A number of possibilities come to mind to explain the site to site differences: preservation, the variation in pinyon production, 

and sampling bias. 

Construction Material 

Archaeological evidence ofthe importance of both pinyon 

and juniper for construction material is ubiquitous. Most 

fundamental is the use of these woods in house construction. The Fremont used both as did the Anasazi. The 

number of trees used for house and kiva construction in the 

Southwest was tremendous. Ray Matheny (1971) has suggested that the demand for pine and juniper for house 

construction during the maximum expansion of the Anasazi 

in southeastern Utah between AD 1000 and AD 1250 may 

have seriously depleted the pinyon-juniper community and 

may have contributed to the abandonment of the Four 

Corners region by the Anasazi in the late 13th century AD. 

The use of both woods for fuel is likewise evident in many 

archaeological contexts in the Desert West. 

Juniper bark fibers are commonly recovered in archaeological contexts both in raw form and woven into 

textiles. Juniper bark open twined matting, for example, 

was in burials, perhaps as shrouds. The Mosida burial on 

Utah Lake, for example, was buried with juniper bark 

twined matting dating to 5,500 years ago (J anetski and 

others 1992). Examples of twined juniper bark matting 

USDA Forest Service Proceedings RMRS-P-9. 1999 
found at Danger Cave date to between 3,000 and 11,000 

BP. At Sand Dune Cave on the Utah-Arizona border 

excavators found bundles of juniper bark dating to th~ early Basketmaker period (about AD 200) or earlier 

(Lindsay and others 1968:86). Artifacts made of juniper 

wood were found in the upper levels of Cowboy Cave. 

These include small, flat, smoothed rectangles identified as 

gaming pieces (Janetski 1980:81). 

Conclusions ------------------------------- Pinyon and juniper have provided important raw material for native peoples for thousands of years in the Desert 

West. They depended on these familiar trees for food fuel 

shelter, and a multitude of other purposes. The e'thno~ graphic data are clear as to these uses. The archaeological 

data raise a number of interesting questions about pinyon 

use over space and time. Additional archaeological research will undoubtedly continue to yield evidences of the 

importance of this unique community in the Desert West. 

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Eagles, and Crater Middens: three residential sites in Owens 

Valley, eastern California. Anthropological Papers No. 67. New 

York: A~nerican Museum of Natural History. 355 p. 

Chamberlm, Ralph V. 1911. Ethnobotany ofthe Gosiute Indians of 

Utah. Lancaster, Pennsylvania: Memoirs of the American Anthropological Association. 2(5): 329-405. 

Coulam, Nancy J.; Sharpe, Saxon. 1993. Paleoenvironment and 

ethnobotany of Old Man Cave, Utah. Ms. On file, San Juan 

Resource area, Bureau of Land Management, Monticello, Utah. 

Egan, Howard R. 1917. Pioneering the west, 1846-1878. Richmond, Utah (privately printed). 

Goodwin, Greenville. 1935. The social divisions and economic life 

of ~he Western Apache. American Anthropologist. 36: 55-64. 

Han:mgton, H. D. 1967. Edible native plants of the Rocky Mountams. Albuquerque: University of New Mexico Press. 

Hewitt, Nancy J. 1980. The occurrence of pinyon pine at Cowboy 

Cave. In: Jennings, Jesse D .. Cowboy Cave. Anthropological 

Papers. 104. Salt Lake City: University of Utah Press: 135. 

Huckell, Lisa W. 1992. Plant Remains. In: Whittlesey, Stephanie M., 

ed. Archaeological investigations at Lee Canyon: Kayenta Anasazi 

farmst~ads in the upper basin, Coconino County, Arizona, Technical Senes 38. Tucson: Statistical Research: 119-131. 

Janetski, Joel C. 1980. Wood and reed artifacts. In: Jennings, 

Jesse D. Cowboy Cave. Anthropological Papers. 104. Salt Lake 

City: University of Utah Press: 75-96. 

Janetski, Joel C.; Hall, Michael J. 1983. An archaeological and 

geological assessment of Antelope Cave (NA5507), Mohave 

Count~, nort~western Arizona. Department of Anthropology 

Techmcal Senes 83-73. Provo: Brigham Young University. 77 p. 

Janetski, Joel C.; Lupo, Karen D.; McCullough, John M.; Novak, 

Shannon A. 1992. The Mosida Site: a middle archaic burial from 

the eastern Great Basin. Journal of California and Great Basin 

Anthropology. 14: 180-200. 

Jennings, Jesse D. 1980. Cowboy Cave. Anthropological Papers 

104. Salt Lake City: University of Utah Press. 224 p. 

Jett, Stephen C.; Spencer, Virginia E. 1981. Navajo architecture: 

forms, history, distributions. Tucson: University of Arizona 

Press. 289 p. 

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Lanner, Ronald M. 1981. The pinon pine: a natural and cultural 

history. Reno: University of Nevada Press. 208 p. 

Lanner, Ronald M. 1983. The expansion of single leaf pinyon in the 

Great Basin. In: Thomas, David H. The Archaeology of Monitor 

Valley: 2, Gatecliff Shelter. New York: American Museum of 

Natural History. Anthropological Papers. 59(1): 167-171. 

Lindsay, Alexander J.; Ambler, J. Richard; Stein, Mary Anne; 

Hobler, Philip M. 1968. Survey and excavations north and east 

of Navajo Mountain, Utah, 1959-1962. Museum of Northern 

Arizona Bulletin 45-Glen Canyon Series 8. Flagstaff: The 

Northern Arizona Society for Science and Art, Inc. 399 p. 

Madsen, David B. 1986. Great Basin nuts: a short treatise on the 

distribution, productivity, and prehistoric use of pinyon. In: 

Condie, C. J. and Fowler, D. D., ed. Anthropology of the Desert 

West. Salt Lake City: University of Utah Press: 21-42. 

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Utah .. In: .Mad~en, David B.; Fike, R. E., ed. Archaeological 

InvestIgatIons m Utah. Utah Cultural Resource Series 12. Salt 

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Mad~en, David B.; Rhode, David. 1990. Early Holocene pinyon 

(Pmus monophylla) in the northeastern Great Basin. Quaternary Research. 33: 94-101. 

Matheny, Ray. 1971. Possible approaches to population distribution studies in southeastern Utah. In: Gumerman, GeorgeJ., ed. 

The distribution of prehistoric population aggregates. Anthropological Reports 1. Prescott: Prescott College: 152-164. 

Reynolds, Linda A. 1997. The prehistory of a pinyon-juniper woodland. Society for California Archaeology Newsletter. 31(4): 1,3-6. 

Rhode, David; Madsen, David B. 1997. Pine nut use in the early 

Holocene and beyond: the Danger Cave archaeobotanical record. 

Ms in possession by the authors. 33 p. 

Rohn, Arthur H. 1971. Wetherill Mesa excavations: Mug House, 

Mesa Verde National Park-Colorado. Archaeological Research 

Series Number 7-D. Washington, DC: U. S. Department of the 

Interior, National Park Service. 280 p. 

Schroedl, Alan R. 1997. [Personal communication]. 

Smith, Ann M. 1974. Ethnography of the Northern Utes. Papers in 

Anthropology 17. Albuquerque: Museum of New Mexico Press. 

288 p. 

Stansbury, Howard. 1852. An expedition to the valley of the Great 

Salt Lake. London: Sampson Low and Sons. (Reprint by Readex 

Microprint). 267 p. 

Steward, Julian H. 1933. Ethnography ofthe Owens Valley Paiute. 

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Steward, Julian H. 1938. Basin-Plateau aboriginal sociopolitical 

groups. Bureau of American Ethnology 120. Washington DC: 

GPO. 346 p. (reprinted 1970. Salt Lake City: University of Utah 

Press). 

Sullivan, Alan P. III. 1992. Pinyon nuts and other wild resources 

in western Anasazi subsistence economies. In: Isaacs, Barry, ed. 

Research in Economic Anthropology, Supplement 6. JAI Press 

Inc.: 195-239. 

Sutton, Mark Q. 1984. The productivity of Pinus monophylla and 

modeling Great Basin subsistence strategies. Journal of California and Great Basin Anthropology. 6(2): 240-245. 

Thomas, David H. 1983. The archaeology of Monitor Valley 2. 

Gatecliff Shelter. Anthropological Papers 59(1). New York: 

American Museum of Natural History. 552 p. 

Van Ness, Margaret. 1986. Desha Complex macrobotanical fecal 

remains. Unpublished masters thesis, Department of Anthropology. Flagstaff: Northern Arizona University. 

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on the Kanab Plateau of northwestern Arizona. Cultural Resource 

Series 4. Phoenix: Bureau of Land Management: 173-180. 

253 
Past, Present, and Potential Utilization of 

Pinyon-Juniper Species 

Peter F. Ffolliott 

Gerald J. Gottfried 

William H. Kruse 

Abstract-Pinyon-juniper species in the Interior West are a sizeable wood fiber resource for products that can be made from smaller, 

irregular stems, and those that capitalize on the unique physical 

and chemical characteristics of the speci~s. However, large-scale 

utilization of these species is largely influenced by management 

programs implemented to improve the range condition, hydrologic 

behavior, and wildlife habitat conditions of the woodlands. The past, 

present, and potential utilization of pinyon-juniper species is presented in this paper, specifically solid wood, chemical, and specialty 

pinyon products. 

The pinyon-juniper woodlands, consisting of approximately 47 million acres in the Western United States 

(Evans 1988), and covering over a quarter of the land area 

of Nevada and New Mexico, are a sizeable wood fiber 

resource. One estimate indicates that approximately 17.6 

million acres of pinyon-juniper woodlands occur in the 

Great Basin area, mainly Nevada and parts of Utah, California, and Idaho (Tueller and others 1979). Pinyon-juniper 

andjuniper woodlands cover 9 million acres in Nevada and 

contain almost 4.4 billion ft3 oftotal wood volume (Born and 

others 1992). Approximately 52 percent of this volume is 

singleleaf pinyon (Pinus monophylla) and 46 percent is 

juniper (mainly Utahjuniper (Juniperus osteosperma). The 

average acre of Nevada woodland contains 6.5 cords (464 

ft3) of pinyon-juniper volume. Approximately 9 million 

acres of pinyon-juniper occur in Utah (Van Hooser and 

Green 1983). The net volume of pinyon andjuniper in Utah 

and Nevada is estimated at over 10.3 billion ft3 (O'Brien, 

This proceedings). 

Pinyon -j uni per species in the Interior West are primarily 

used for firewood, posts, and pinyon nuts. These trees, 

however, are potentially useful for the manufacture of wood 

products that can be made from smaller, irregular stems, 

and those that can use the unique physical and chemical 

characteristics of these species. Past, present, and potential uses of pinyon-juniper species are presented in this 

paper, specifically solid wood, chemical, and other pinyon 

products. Past and present utilization practices are reIn: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Peter F. Ffolliott is Professor, School of Renewable Natural Resources, 

University of Arizona, Tucson. Gerald J. Gottfried is Research Forester and 

William H. Kruse is Range Scientist (retired), USDA Forest Service, Rocky 

Mountain Research Station, Flagstaff, AZ. 

254 

viewed, followed by a discussion of potential future uses of 

pinyon-juniper species. 

Solid Wood Products 

Solid wood products are those made of wood in its natural 

structural form. Pinyon-juniper species are used in their 

natural form for firewood and posts. The wood is also sawn 

into railroad ties and mine timbers. In addition, the wood 

may be reconstructed with adhesives to obtain products 

such as veneer, particleboard, and cement board. 

Firewood 

Pinyon-juniper species have been used longer and more 

extensively for firewood than any other product (Barger 

and Ffolliott 1972; Born and others 1992; Ffolliott and 

Clary 1986). In the Interior West, this wood remains the 

main fuel in some rural localities, while the popularity of 

wood-burning fireplaces contributes to its urban demand. 

In Nevada, the demand for firewood peaked in 1982 but 

remained fairly constant through 1989 (Born and others 

1992). Harvesting is done by commercial operators for sale 

in population centers like Salt Lake City, Phoenix, Albuquerque, Las Vegas, and Los Angeles, and by individuals 

for personal use. Commercial tribal woodyards exist on 

several reservations (for example, Uintah and Ouray Ute 

Reservation in Utah) to provide employment and to generate income. Use of designated harvesting areas is an effective method to initiate sustainable management on tribal 

woodlands (Miller 1997). Wagstaff (1987) reported that 

most ofthe cutting permits for Federal lands were issued to 

private individuals. Surveys in New Mexico (McLain 1989) 

indicated that 41 out of 400 households harvested firewood 

while 25 out of 400 households in Utah conducted harvests 

(McLain 1997). In Albuquerque, as late as 1940, annual 

commercial firewood sales were estimated to exceed 6,500 

tons (Space 1940). Demands remain high, almost 107,000 

cords of pinyon (P. edulis) and assortedjuniper species were 

harvested for firewood in New Mexico in 1986 (McLain 

1989). The use of firewood appears lower in the Great Basin 

area. Public land records in Nevada indicate that 12,096 

cords were sold in 1989. Although the harvest of forest 

species, such as lodgepole pine (P. contorta) and aspen 

(Populus tremuloides), and horticultural fruitwood, such as 

peach (Prunus persica), meets much of Utah's firewood 

demands, approximately 4,628 cords of juniper and pinyon 

were harvested for firewood in 1992 (McLain 1997). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Heat content, ignition, and burning characteristics are 

important firewood characteristics. Heat content,which is 

directly proportional to wood density, is the most important 

characteristic of wood used as fuel, while ignition, flaming 

characteristics, and fragrance are important attributes of 

fireplace wood (Barger and Ffolliott 1972). Based on these 

criteria, pinyon and juniper species make excellent firewood. There has been some interest in using pinyon and 

j uni per chi ps for commercial energy prod uction (Henderson 

and Baughman 1987); however, the interest in biomass 

fuels has fluctuated. 

Firewood is commonly marketed haphazardly, with small 

independent operators working intermittently. Product 

quality and quantity sold as a cord unit are often questionable. The few commercial woodyards in the region can 

experience difficulty locating dependable sources and obtaining consistent quality. In the past, most firewood for 

the Utah Wasatch Front region came from salvaging dead 

material in chained and cleared areas. These sources are 

now depleted and cutters are cutting more live trees and 

travelling further to harvest them (Wagstaff 1987). Commercial firewood cutters in southern Utah dislike harvesting multi-stemmedjunipers and prefer to cut other species. 

Harvesting juniper is labor intensive per unit of wood 

because of the small multiple stems, and because windblown soil lodged in the rough bark and the high wood 

density cause significant wear on saws. Transporting firewood to market areas is critical to the economic efficiency 

of marketing (LeBaron and Johnson 1965; Sowles 1966). 

Transportation costs are highest for small and irregular 

shipments. Intense competition keeps wholesale prices and 

profits low (Schmidt 1995), resulting in a high turnover 

among firewood operators. 

The average wholesale price for firewood delivered to 

brokers within the Four Corner States, Southern California, and Nevada ranged from $50 to $100 for pinyon and 

$45 to $110 for juniper; the hjghest prices paid were in 

Southern California (Schmidt 1995). In Utah and Nevada, 

wholesale prices for pinyon firewood are $50 to $60 and for 

juniper are $45 to $55. Species preferences varies throughout the Interior West. Pinyon is preferred in Salt Lake City 

and is sold for $10 to $15 more a ton than juniper, while 

juniper is preferred in the Las Vegas area (Wagstaff 1987). 

In the Southwest, pinyon is the preferred species in New 

Mexico, while junipers are preferred in Arizona. Firewood 

generally is purchased in the spring and summer and is 

split and dried before selling to distributors. However, air 

pollution and resulting "no-burn days" in major urban 

centers, such as Salt Lake City and Phoenix, and recent 

restrictions on the construction of new wood-burning residential fireplaces, such as in the Phoenix area, may impact 

the regional demand for firewood. 

Posts 

Juniper species have been used historically for posts, 

because of their outstanding natural durability. Many 

posts were cut for personal use and for sale by commercial 

enterprises during the settlement period and growth ofthe 

livestock and farming industries. Posts are classified as 

line or corner posts depending on size; more than a third of 

the posts in Nevada are the larger corner posts (Born and 

USDA Forest Service Proceedings RMRS-P-9. 1999 

others 1992). Juniper is used as stub posts in power and 

telephone line construction and for highway guardrails, 

although increased use of steel posts and preservativetreated pine and Douglas-fir (Pseudotsuga menziesii) has 

curtailed these uses. The annual cut of juniper posts in the 

late 1960s was approximately 300,000 (LeBaron 1968). 

Federal agencies in Nevada sold almost 38,000 posts in 

1989 (Born and others 1992). Minimum specifications for 

juniper posts are based on a minimum serviceability of 80 

percent after 40 years (Meagher 1940). Tests indicate that 

ajuniper post could last over 50 years (Barger and Ffolliott 

1972). Heartwood diameter is the limiting criterion. 

Pinyon is not favored for posts because it seldom grows in 

a suitable form and is not a durable wood. Under normal 

conditions, untreated pinyon posts seldom remain in service beyond 5 years. Some pinyon is harvested for home 

construction, corrals, and fences. Navajos still use it for 

hogan poles and roof beams (Lanner 1981). 

Harvesting posts in pinyon-juniper stands is a selective 

operation. Stems must be relatively small, slender, and 

straight. Young- and intermediate-aged stands are best for 

locating harvestable stems. Suitable posts are not found in 

stands that have been selectively cut or "high-graded" for 

posts in the past. Split posts are superior to round posts, 

since there is less sapwood in contact with the soil and less 

chance for the post to loosen as the sapwood rots. Commercial post cutting and selling is a part-time job for people 

involved in farming or ranching. A few larger post and pole 

yards in the region attempt to stock and sell juniper posts 

on a continuing basis. Born and others (1992) suggested 

that harvesting more valuable posts should be integrated 

with firewood harvesting in the same area to maximize 

returns. 

Sawn Products 

Pinyon-juniper species are not widely utilized for sawn 

products because of their small size and poor growth form. 

Other problems are related to high wood density and grit, 

which causes saw wear, and resin buildup in the equipment. Only 14,800 acres of pinyon-juniper sawtimber have 

been identified in Utah (Van Hooser and Green 1983). Less 

than 2,000 fum of pinyon timber was harvested in Utah in 

1992; this was less than 0.5 percent of the total amount 

harvested for saw logs, house logs, or other prod ucts (Keegan 

and others 1995). However, railroad ties and mine timber 

have been cut from pinyon by small mills in the past, 

principally for use by the mining industry. Pinyon railroad 

ties are tougher and more resistant to breakage than ties 

cut from other softwood species in the region. 

Juniper species have been cut into rough lumber by small 

mills. The lumber was usually specially ordered for use in 

furniture or novelty items, the latter including book ends, 

lamp basis,jewelry boxes, and small chests (Voorhies 1977; 

Swan 1995). These products capitalize on the unique fragrance, color, and grain patterns of juniper. 

Veneer 

Juniper species in the Interior West are physically similar to eastern redcedar (Juniperus virginiana) in many 

respects and, therefore, are considered for similar uses 

255 
such as veneer and particleboard. USDA Forest Service 

tests indicated that Utah (J. osteosperma) and alligator 

juniper (J. deppeana) can be satisfactorily rotary cut or 

sliced into veneer sheets (Englerth and others 1953). Cutting characteristics and surface quality compared 

favorably with eastern redcedar. However, the veneers cut 

from Utah and alligator junipers are inadequate substitutes because of the deeper, more striking color, and more 

pronounced and lasting fragrance of eastern redcedar. 

Veneers from the westernjuniper species could be satisfactory for less demanding uses in furniture and paneling 

products. Questions of marketing veneers cutfromjunipers 

in the region remain. 

Particleboard 

The wood of almost any species can be used to manufacture particleboard, although softwoods and low-density 

hardwoods are favored. Pinyon could provide excellent 

material for particleboard, although ponderosa pine (P. 

ponderosa) is cheaper, often more abundant, and has the 

same characteristics. Particleboard made from singleleaf 

pinyon and Utah juniper logs was tested at the Forest 

Prod ucts Laboratory a t Madison, Wisconsin (M urphy 1987). 

The Laboratory indicated that pinyon or juniper panels 

were inferior to those made from other western softwoods, 

but that it would be possible to make a urea-bonded panel 

that was satisfactory, based on strength and stability, for 

interior use. Additional tests at a laboratory in Germany 

indicated that panels made from chipped material, including bark, met the physical property levels for commercial 

panels. 

Juniper species offer better opportunities for particleboard with distinctive qualities because of their specific 

gravity, texture, color, and fragrance (Ffolliott 1977). Alligator and Rocky Mountain juniper (J. scopulorum) bolts 

were converted into flakes 1 inch long, 0.015 inch thick, and 

random widths in a limited test (USDA Forest Service 

1966). The flakes were then bonded with 8 percent urea 

resin into a single-layer medium-density particleboard. 

Strength and shrinkage characteristics of these boards 

were similar to those of a comparable ponderosa pine 

particleboard. The tests indicated that satisfactory particleboard can be manufactured from alligator and Rocky 

Mountain juniper. Markets for this product have not been 

adequately developed. 

Cement Board 

Tests of pinyon andjuniperwoods have determined their 

potential for use in cement board (Murphy 1987). This 

product is composed of cement, wood fiber, and water, and 

is fire resistant, relatively unaffected by water, and can be 

worked like particleboard. Cement board has a number of 

uses including exterior siding, air conditioning and utility 

ducts, and all-weather foundations for basements. 

Chemical Products 

Chemical products include those made by chemically 

treating or altering wood fiber and products derived from 

256 

the chemical constituents or extractives of wood. Charcoal 

manufacture through carbonization and pulping are examples of chemical alteration of wood. Chemical constituents including turpentine, rosin, and a variety of oils can be 

obtained through distillation of wood and foliage and 

solvent extraction processes, or through processing oleoresins collected from living trees. Chemical utilization offers 

advantages for pinyon-juniper species, since stem size and 

form are not critical. 

Charcoal 

All of the pinyon-juniper species are suitable raw material for charcoal. All wood is about 50 percent carbon. As a 

consequence, the yields of charcoal from various wood 

species are proportional to the density of the wood. Denser 

species are preferred, since charcoal yield per unit of wood 

volume will be greater. Gambel oak (Quercus gambelii), a 

frequent associate of pinyon-juniper species in the Interior 

West, is well suited to the production of lump charcoal, 

since it is a heavy wood and will produce corresponding 

heavy lump charcoal (Barger and Ffolliott 1972; Voorhies 

1977). Although the lighter pinyon and juniper woods 

produce a lighter, less desirable lump product, pinyon and 

juniper charcoals were used as a smelter fuel in the early 

mining operations throughout the region (Lanner 1981). 

Well-made charcoal contains approximately one-halfthe 

volume and one-third the weight of the wood from which it 

is made (USDA Forest Service 1961). Using an average 

conversion value of 32 percent, calculated charcoal recovery per cord of wood for pinyon is 710 lb, for Utahjuniper is 

715 lb, and for alligator juniper is 635 lb. Actual yields of 

charcoal depend on the efficiency of the converting equipment and process used. Yields of 32 percent from pinyon 

and 36 percent from Utah juniper were obtained in a sheet 

metal kiln in Utah (Johnson 1965), while an average charcoal yield of 30 percent was obtained from pinyon and 

juniper in a block kiln in Colorado (Troxell and Johnson 

1964). 

The lighter lump charcoal produced from pinyon and 

juniper has a disadvantage in the market. A Utah study of 

charcoal potential for these species concluded that the best 

opportunities were in producing, bagging, and selling lump 

charcoal. This conclusion was based on a lack of competition among producers of bagged lump charcoal in the 

region, higher profit-to-cost ratios, and an assumption that 

consumers recognize the inherent advantages oflump charcoal. The same study pointed out the disadvantage of 

selling lump charcoal to briquetting plants, who incorporate their own charcoal production facilities into the operation and commonly buy outside charcoal at marginal prices. 

Pulping 

The physical and chemical properties of alligator juniper 

wood, its sulfate pulping characteristics, and sulfate pulp 

properties have been evaluated (Martin 1961). The evaluation indicated a relatively high lignin content, low pentosan content, and high extractives content, which are 

detrimental to the yield and quality of pulp. 

The wood pulped satisfactorily but produced low yields 

that required nearly twice the quantity of bleach chemical 

USDA Forest Service Proceedings RMRS-P-9. 1999 
than is commonly required for bleachable pulps. The 

strength of the pulp produced was intermediate between 

hardwood and softwood sulfate pulps. The pulp was too 

difficult to bleach for white paper stock, too weak for 

unbleached high-grade bag and wrapping paper, and too 

soft for corrugating board medium. Juniper sulfate pulp is 

probably best suited in blends with other softwood pulps 

(Martin 1961). 

Pinyon has been experimentally pulped with satisfactory 

results (Barger and Ffolliott 1972). Brightness and bleaching characteristics are similar to those of ponderosa pine. 

However, because ofthe shorter fiber lengths, pulp strength 

is below the average for softwood pulps. One test found that 

pinyon and juniper could be used to make good quality 

Kraft-paper (Murphy 1987). 

Information on mechanical pulp from these species is 

limited. However, high lignin and ex-tractive levels could be 

a bonus for improving wet-strength properties and durability for packaging or paper overlays (Laufenberg, T. 1997 

personal correspondence). 

Pinyon-juniper stands offer some opportunity for pulpwood production since they can contain suitable material 

and occupy large, continuous areas. Although the growth 

form and debarking characteristics of pinyon are particularly adaptable to pulpwood processing, the economic feasibility of pulping pinyon-juniper species in the region is 

questionable. Environmental concerns related to the pulp 

industry must also be considered. 

Extractive-Based Products 

Appreciable quantities of extraneous chemical, called 

extractives, are found in pinyon-juniper species. These 

extractives occur mainly within cell cavities and intercellular structures such as resin ducts (Voorhies 1977). Some 

extractives are obtained from the sap or gum by tapping 

living trees, while others are obtained from chipped or 

shredded wood by solvent or steam distillation. 

Pinyon wood contains large quantities of oleoresin or 

gum. Resin is collected by tapping the living trees in a 

manner similar to that used in southern pine species. 

Properties of the pinyon gum determine its potential use. 

The resin collected in an early Arizona study contained 20 

percent volatile constituents or gum turpentine and 80 

percent rosin (Deaver and Haskell 1955). Products obtained from laboratory analyses of pinyon resin include 

spirit, linseed oil, and tung oil varnishes, ester gum, and 

zinc resinate (Westgate 1943). Murphy (1987) reported 

tha t the branches and needles of pinyon and Utah j uni per 

contain four times the resin of Douglas-fir. American Indians traditionally use pinyon pitch for a number of purposes. 

The Zunis of western New Mexico use it as an antiseptic, a 

pottery glaze, and burn it during religious ceremonies 

(Miller and Albert 1993). 

Juniper woods contain large quantities of oily, fragrant 

extractives that are rich in cedrol and associated essential 

oils. Eastern and southern juniper species are exploited 

commercially for the prod uction of cedarwood oil marketed 

for a variety of pharmaceuticals, perfumes, polishes, and 

insecticides (Barger and Ffolliott 1972; Voorhies 1977). 

However, the physical and chemical properties ofthejuniper species in the Interior West are largely unknown. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Foliage of juniper species contains fragrant, oily extractives potentially valuable as essential oils. Northern whitecedar (Thuja occidentalis) and eastern red cedar in the 

eastern United States have been commercially used for leaf 

oils (Bender 1963). While the physical and chemical 

properties of the leaf oils of Interior West junipers are 

unknown, the main components, as in most conifers, should 

be the terpene and sequiterpene series. 

Other Pinyon Products ____ _ 

Pinyon has been historically a source of edible nuts and 

Christmas trees. Pinyon species produce nut crops at intervals of 4 to 7 years (Barger and Ffolliott 1972). Pinyon nuts 

are harvested commercially or by individuals for personal 

use. Nut crops are more frequent from trees where the 

species flourishes and are less frequent near the fringe of 

the type. Because of the staggered nature of the annual 

crops among sites, locally "good crops" usually occur somewhere almost every year. Nut yields from the better stands 

have been estimated to reach 300 lb/acre in a good crop year 

(Hamilton 1965). Crop variability is shown by data from 

woodlands administered by the USDI Bureau of Land 

Management in Nevada (Born and others 1992). Commercial harvesters collected about 115,000 Ib of nuts in 1984, a 

peak year, while less than 3,000 Ib were collected in 1989, 

a drought year. This variability is a problem for nut brokers 

and processors who prefer a constant supply to meet production and market demands. The price of pinyon nuts in 

the Southwest fluctuates between years and within a year 

depending on availability (Tanner and Grieser 1993). However, proper storage and handling of nuts and stable nut 

prices during bumper years would help sustain the nut 

market (Tanner and Grieser 1993). 

Pinyon nuts are a popular woodland product throughout 

the West, which may justify increased investment in processing and shipping. Bags of unshelled Nevada pinyon 

nuts were sold in an Arizona supermarket chain during the 

winter of 1995. This was a poor nut year in much of the 

Southwest, and the bags of nuts sold out rapidly. Although 

the profitability ofthis effort is unknown, the suppliers and 

supermarket must have anticipated a profit. In November 

1997, unshelled Nevada pinyon nuts were sold in bulk at 

one rural southern California produce stand for $5.95 a 

pound. Pinyon nuts have high dietary value and compare 

favorably with pecans and other nuts in protein, fat, and 

carbohydrates (Lanner 1981). Singleleaf pinyon nuts are 

10 percent protein, 23 percent fat, and 54 percent carbohydrates. Commercial interests in New Mexico are attempting to increase the demand for pinyon nuts and to create 

additional pinyon nut products and markets. 

Pinyon nuts are an important food for American Indians. 

The Washoe of Nevada, for example, have established 

pinyon collection allotments in the Pine Nut Mountains 

(Miller 1997). 

Pinyon Christmas trees are favored by residents of the 

Interior West. These trees are harvested mostly from natural stands, although the species are also prod uced in commercial plantations (Barger and Ffolliott 1972). Recent 

declines in the demand for pinyon Christmas trees in some 

areas is partly due to a decreased supply of high-quality 

trees because of previous harvesting in the more accessible 

257 
stands. Christmas tree cutting remains a popular recreational activity by the general public. Increasing use of 

artificial Christmas trees has also contributed to the decline in demand. However, the demand for pinyon Christmas trees in the Salt Lake City area has remained high 

with prices for pinyon being comparable to those for several 

species of tree-farm grown trees (Born and others 1992). 

Potential Futu re Uses 

More intensive and multiresource management of the 

pinyon-juniper woodlands in the Interior West depends on 

the development of economically and technically viable tree 

products. Increased demand for manufactured tree products might justify increased stumpage prices and investment in land management to improve.ecosystem conditions 

and tree growth and yield from stands on the better sites. 

A main reason for low levels of management of pinyonjuniper woodlands is due to the poor economic return for all 

tree and non-tree products. 

A group representing the forest products industry, local 

land owners, and government and nonprofit agencies was 

established to develop products and markets for western 

juniper (J. occidentalis) areas of Oregon (Swan 1995). The 

group has supported marketing tests of juniper for fencing, 

decking, and landscape timbers as well as flooring, cabinets, furniture, interior paneling, and novelty items. Swan 

(1997) stressed the importance of knowing the species' 

characteristics, potential products, manufacturing capabilities, and existing and potential market conditions. Many 

western juniper trees have relatively straight boles which 

gives them an advantage over multi-stemmed juniper species. These western junipers can be cut for logs and sawn 

and processed for a number of products. Different harvesting methods, including the use of mechanical delimbers, 

have been evaluated to determine relative production and 

affects on soils (Swan 1997). 

However, a potential for new and expansion of existing 

products exists in the Interior ·West. The use of chips and 

raw fiber in particleboard, composite doors, and furniture 

needs further study. New technologies and compounds for 

binding chips and fiber should produce new product options. The decline in harvesting of forest tree species may 

increase the use of woodlands species, primarily pinyon, in 

the pulp and paper industry. 

Chipping on-site, particularly of whole trees, would allow 

for more efficient harvesting by mechanical equipment 

(Henderson and Baughman 1987). The physical and economic feasibility of these methods would depend on the 

type of equipment used, and on site (slope, rockiness, soil 

conditions) and stand conditions (density, tree size, volume). Henderson and Baughman (1987) mentioned the 

need to develop equipment that is specifically adapted to 

terrain and operating conditions found in the woodlands. 

Economic viability also would depend on the costs of transporting the chips. 

A variety of mechanical equipment, ranging from large, 

self-propelled machines to small, trailer mounted units, 

could be developed for woodland use. Mechanical methods 

should be used only after consideration of stand and site 

conditions. Woodland sites are divided into high and low 

categories based on their ability to grow wood products 

258 

(Born and others 1992); high-site woodlands, which usually 

contain pinyon, occupy about 5.9 million acres in Nevada. 

High-quality stands on good sites should be managed under 

a silvicultural system that sustains the production of tree 

and other woodland products and maintains woodland 

health (Gottfried and Severson 1993). Mechanical methods 

allow for harvesting some smaller trees left in harvested 

stands and for treating marginal juniper stands. However, 

the use of mechanical methods must not repeat the mistakes of the pinyon-juniper control program of the late 

1950's through the early 1970's, which resulted in large 

continuous openings that are detrimental to many wildlife 

species and aesthetically displeasing. Openings should be 

narrow enough to provide edge and encourage herbaceous 

use by wildlife. Trees and groups of trees should be left in 

treated areas to provide a savanna landscape, and adjacent 

untreated areas should be sufficient for wildlife. 

Sustainability of tree resources for the future must be 

considered. Some woody material, including snags, should 

be left for nutrient recycling, erosion control, wildlife shelter, and herbaceous plant and tree regeneration. Archeological sites would have to be identified and protected. 

There is a growing demand for rustic furniture and 

novelty items made from native woods. The potential exists 

in many rural and American Indian communities to manufacture these items, provided dependable markets are developed. Observations in rural New Mexico indicate that 

high quality items, especially furniture, command relatively high prices. Initial start-up would require some 

training of wood workers and artisans, but the effort would 

benefit the local economies. 

Management Implications ___ _ 

The pinyon-juniper woodlands of the Interior West represent a vast resource of wood fiber, that is potentially useful 

for many prod ucts. However, large-scale u tiliza tion of these 

species is influenced by management programs implemented to improve woodland range conditions, hydrologic 

behavior, and wildlife habitat conditions. Occurrence of 

pinyon-juniper species is generally detrimental to forage 

production (Clary and others 1974), but they protect naturallandscapes from excessive soil loss, provide habitat for 

wildlife populations, and enhance aesthetic values. 

Integrated resource management objectives for the pinyon-juniper woodlands must be achieved in conjunction 

with ecologically sound land management. Environmental 

concerns drive management programs for these woodlands 

throughout the Interior West. Enhancement of species and 

landscape diversity, in both spatial and temporal planes, is 

a major concern. Utilization of pinyon-juniper species for 

wood products must be carefully coordinated with the 

management of other resources. Future utilization of pinyon-juniper species in the Interior West depends on market 

availability and other economic considerations such as 

efficient tree harvesting and wood processing operations. 

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259 
Endemic and Endangered Plants of PinyonJuniper Communities 

Sherel Goodrich 

Lori Armstrong 

Robert Thompson 

Abstract-Habitat relations between pinyon-juniper and narrow 

endemic plants of Utah and management implications of these 

relations are evaluated. 

For this paper a narrow endemic plant is considered to be 

one that is restricted to one or a few counties in one or 

perhaps two States. Some ofthese are known from only a few 

populations while others are known from many. Nearly all 

plants of Utah and other Western States that have been 

listed as threatened or endangered by the U. S. Fish and 

Wildlife Service and those listed as sensitive by other agencies are narrow endemics. Ute ladies tresses (Spiranthes 

diluuialus), which is listed as threatened, is a notable exception with distribution including Colorado, Utah, Wyoming, 

Montana, and, at least historically, Nevada. That species is 

included in this paper based on its threatened status. Consideration of biological diversity, scientific interest including potential medicinal uses, and other features of these 

relatively rare or at least restricted plants is important to 

land use planning and management. 

Colorado pinyon (Pinusedulis Engelm.), singleleafpinyon 

(Pinus monophylla Torr. & Frem. in Frem.), and Utah 

juniper (Juniperus osteosperma [Torr.] Little) are the common trees ofthe pinyon/juniper thermal belt of Utah. Within 

their thermal belt, these generalists are found on nearly all 

geologic strata and soil types. Rocky Mountain juniper 

(Juniperus scopulorum Sarg.) does not seem as thermalsensitive as the above species, and it is more common at 

higher elevations. It is less common on exposed geologic 

strata than the above species, and it is not so commonly 

found in closed stands. It is also more common where the soil 

mantle is well covered with vegetation and litter. Atwood 

and others (1991) listed nearly 70 taxa of narrow endemic 

plants for pinyon-juniper communities of Utah, and 22 

species for juniper communities, and two for Rocky Mountain juniper communities. Many of these endemics have 

been listed as threatened, endangered, or sensitive or have 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedin~s: 

ecology and management of pinyon-juniper communities within the InterlOr 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogd:n, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountam Research 

Station. 

Sherel Goodrich is a Forest Ecologist, Ashley National Forest, Intermountain Region, Forest Service, U.S. Department of Agriculture,. Verr:al,. UT 

84078. Lori Armstrong is a Botanist, Richfield and Cedar Clty Dlstncts, 

Bureau of Land Management, U.S. Department of the Interior, Richfiel~, UT 

84701. Robert Thompson is a Range Conservationist, Manti-LaSal Natl?nal 

Forest, Intermountain Region, Forest Service, U.S. Department of Agnculture, Price, UT 84501. 

260 

been considered for listing. When plant communities are 

compared for presence of narrow endemic plants, it is clear 

that pinyon-juniper and desert shrub communities support 

most of these in Utah (Welsh 1979). 

Because many of these plants are known within the 

pinyon-juniper thermal belt and sometimes coexist with 

these trees, the assumption might be made that some or 

many of these could be pinyon-juniper obligates or at least 

benefited by pinyon-juniper association. This paper provides an evaluation of relationships between pinyon-juniper 

and many of the narrow endemic plants known from the 

pinyon -j uni per thermal belt ofU tah. This ev al ua tion is quite 

restricted to narrow endemic plants. There are other plants 

of wider distribution that might show a positive relationship 

with pinyon-juniper and be indicators of community type or 

seral status such as pinyon-juniper lousewort (Pedicularis 

centranthera Gray). 

Sources of Information and 

Concepts 

Much of the information known about narrow endemic 

plants is a function of botanical collections. Information 

taken with botanical collections often includes plant community, soil texture, geologic formation, elevation, and other 

habitat features. Numerous collections with this information become the foundation for written floras including A 

Utah Flora (Welsh and others 1993), which incl udes geologic 

information for many of the narrow endemic plants of Utah. 

It is a major source of information for this paper. 

The inclusion of geologic information in that work is 

largely a function of observations of close relationships 

between plants and geology made by Dr. Stanley L. Welsh 

beginning with his survey of Dinosaur National Monument 

(Welsh 1957). From this point, Welsh continued to observe 

these relationships throughout Utah and sought help from 

geologists in recognizing geologic strata (Welsh 1978; 1984). 

His interest and knowledge became infectious, and his 

students caught the fascination of the strong relationships 

between narrow endemic plants and geologic substrate. Use 

of geological maps and observations for exposed geologic 

strata became standard tools in surveys for endemic plants 

as well as more common plants (Goodrich 1981; Goodrich 

1984' Goodrich and Neese 1986; Huber 1995). Looking for 

thes~ unusual habitats yields new species and range extensions of other species, and contributes greatly to the knowledge of the flora of Utah. 

Surveys conducted specifically for plants listed or considered for threatened and endangered status such as those of 

Neese and Smith (1982), Petersen and Baker 1982, Shultz 

USDA Forest Service Proceedings RMRS-P-9. 1999 
(1982), Shultz and Mutz (1979), Fertig (1995), and Heil and 

Melton (1995) are greatly facilitated by recognizing and 

searching on appropriate exposed geologic strata. The above 

and several other publications and surveys are major sources 

of information for this paper, including Franklin (1989, 

1992, 1993). In addition, numerous collections of these 

species have been made by the authors of this paper, and 

field experience while making those collections are part of 

the information provided here. 

Edaphic control by geological formations is greatest in 

areas where the strata are exposed (Welsh 1979). For geologic substrates to be controlling, in Utah at least, the area 

must be xeric. Desiccation is apparently a necessity for 

ultimate expression of edaphic control of vegetation (Welsh 

1984). On geologic badlands or semibarrens, the interaction 

of various substrates with low annual precipitation through 

long periods has led to the demonstration of edaphic differences on a grand scale. Soil formation is minimal. The 

substrate surface is often merely residual parent material 

only slightly modified from that of a few inches below the 

surface where conditions for plant growth are often rigorous 

at best. 

Geologic or edaphic control of plants is not as common in 

areas of high precipitation. Where precipitation is abundant, the influence of water has a strong tendency to override the influence of geology. However, xeric conditions are 

not only associated with low precipitation. They are also 

associated with steep slopes and cliff faces, and with wind 

swept slopes and ridges, especially where geologic substrates with features that shed water quickly are exposed. 

Thus, some higher elevations in Utah with relatively high 

precipitation provide xeric or at least desiccating habitats 

where plant specialists are protected from competition of 

generalists. Plants capable of establishment and reproduction in these harsh conditions are few in number. Competition is therefore limited (Welsh 1978). Thus Utah, with 

much exposed geology under xeric conditions, supports numerous relatively narrow endemic plants. 

The concept that narrow endemic plants are favored by 

exposed geology under xeric conditions is well supported by 

the large number of such taxa found in such habitats, and 

relatively few that have been found where the geology is well 

mantled by vegetation. Viewing the photographs of habitats 

of the threatened, endangered, and sensitive species provided in Atwood and others (1991) provides an excellent 

array of semibarrens or badlands of Utah. There are a few 

plants listed in that work for which the habitat is shown to 

be well mantled by vegetation. With few exceptions, these 

plants are broadly distributed and are included in that work 

based on a narrow range known in Utah. Examples are 

Potentilla palustris (LJ Scop., which has circumboreal distribution, and Carex leptalea Wahl., which is known from 

Alaska to Labrador and south to California and Florida. 

Also, viewing the photographs of rare plants of Wyoming 

as provided in Fertig (1994) and endangered and sensitive 

plants of Idaho and Wyoming as provided by U.S. Department of Agriculture, Forest Service (without date of publication) shows a similar theme. However, the works from these 

States seem to show more species in areas of dense vegetation. Once again, however, several of these taxa from wellvegetated habitats are not narrow endemics but are listed in 

these works based on narrow distribution within the state 

USDA Forest Service Proceedings RMRS-P-9. 1999 

only. Examples are Carex bauxbaumii Wahl. with 

circumboreal distribution and Salix candida Fluegge ex 

Willd., which is known from Alaska to Labrador and south 

to British Columbia and Indiana. 

The photographs of habitat for sensitive plants of the 

Humboldt National Forest, NV, which are mostly narrow 

endemics (U.S. Department of Agriculture, Forest Service 

1991), show a propensity ofthese plants for open, sunny sites 

free oftrees. Where pinyon-juniper are present, the endemic 

plants often grow in rock outcrops or talus within pinyonjuniper communities. 

Plants that occupy well-developed soils tend not to be 

specialists, and they are broadly distributed (Welsh 1984). 

The Duchesne River Formation of the Uinta Basin, Utah, 

provides an example. At lower elevations this formation 

weathers to badlands or semibarrens as seen along U.S. 

Highway 40 between Roosevelt and Vernal and along Utah 

Highway 121 between Lapoint and Vernal. At higher elevations (around Strawberry Reservoir) under higher precipitation much ofthis formation is comparatively well mantled by 

vegetation. At the lower elevations where the formation has 

weathered to semibarrens, at least 17 taxa of narrow endemic plants have been found. None are known from the 

upper elevations ofthe formation where it is well mantled by 

vegetation. 

The propensity of narrow endemic specialists for open 

sites of badlands or semibarrens with little competition from 

generalists is critical to understanding their relationships 

with pinyon and juniper. 

Relation Between Narrow Endemic Plants 

to Pinyon and Juniper 

The list of plants treated below was derived mostly from 

Atwood and others (1991). However, other narrow endemics 

listed by Welsh and others (1993) for pinyon or juniper 

communities of Utah are included. Page limitations for this 

paper prevent a discussion of each of the numerous narrow 

endemic plants of Utah found within the pinyon-juniper 

belt. The representative taxa discussed below are arranged 

in three categories of apparent relationship to pinyon-juniper. These categories are obligatory, apparent associate, and 

incidental. An expanded list oftaxa for each ofthese categories without discussion is also provided below. 

Obligatory or Semiobligatory 

Arabis uiuariensis Welsh Park rockcress-Geology/soils: 

sandstone and limestone outcrops and sandy soil. Plant 

Communities: Mixed desert shrub, pinyon-juniper. Notes: 

Presence on sandstone and limestone outcrops, and in mixed 

desert shrub communities indicates no obligatory relationship with pinyon or juniper. However, this plant does grow 

under the canopy of and in the duff of these trees on sandy 

soil, and apparently it is more abundant and vigorous in 

shade including that provided by pinyon or juniper. A positive relationship is strongly indicated between this plant 

and pinyon-juniper. 

Camissonia exilis (Raven) Raven Meager camissoniaGeology/soils: Gypsiferous Plant communities: sagebrush, galleta, pinyon-juniper. Notes: This species seems to 

261 
have a true affinity for growth under the canopy of other 

vegetation. Most often the other vegetation is either pinyon 

or juniper. However, on some occasions it grows under the 

canopy of bitter brush and rarely in the open. The presence 

of duff is not a deterrent to its growth. It is unknown if there 

is dependence on canopy cover or duff or both, but a strong 

relationship to pinyon-juniper is evident. 

Echinocereus triglochidiatus var. inermis (K. Schum) 

Rowley Spineless hedgehog cactus-Geology/soils: Brushy 

Basin and Saltwash Formations, and sandstone members of 

the Morrison Formation, shallow, rocky soils. Plant communities: Pinyon-juniper/galleta grass, pinyon-juniper! 

yucca/black sagebrush. Notes: This plant shows affinity for 

shade of pinyon-juniper trees and tall mountain brush. 

Penstemon pinorum L. Shultz & J. Shultz Pinyon penstemon-Geology/soils: Often on Claron Limestone or its 

gravels. Plant communities: Pinyon-juniper, mountain 

mahogany, ephedra, oak, sagebrush, and less commonly 

greasewood. Notes: The specific epithet for this species is 

definitely descriptive of its habitat. Although it has been 

found in shrubby communities, it is most often found in duff 

directly under pinyon-juniper canopy and becomes increasingly less common into open interspaces. When found in 

association with shrubs, it is often not far from thick pinyonjuniper cover. In such instances, it is again found in the litter 

underneath woody species, becoming uncommon in the 

open. It is unclear whether the association is a function ofthe 

duff or the protection of the canopy cover or both, but a 

dependency is indicated. Removal of pinyon-juniper canopy 

has been associated with reduction of the species. 

Apparent Associates 

Allium geyeri var. chatterlyi Welsh Chatterley's onionGeology/soils: Soils are mostly fine textured sandy loams, 

found in small pockets, protected depressions, and cracks in 

open slick rock of the Navajo Sandstone Formation. Plant 

communities: Ponderosa pine/ManzanitalWestern wheatgrass, Ponderosa pine/Oak brush/Ross sedge. Notes: Although this plant is found in association with ponderosa pine 

and pinyon, it prefers the more unshaded sites. 

Astragalus desereticus Barneby Desert milkvetch-Geology/soils: Sandy to clay soils of the Moroni Formation (ash 

flow tuff) and occasionally on a sandy member of the North 

Horn Formation located just above the Moroni Formation. 

Plant communities: Pinyon-juniper (mostly Utahjuniper) 

with an understory including bitterbrush and Indian 

ricegrass. Some plants have been found in a basin big 

sagebrush community adjacent to the pinyon-juniper type. 

Notes: This plant has a strong affinity for the Moroni 

formation and pinyon/juniper/bitterbrush communities. 

Draba pectiniphila Rollins Woods draba-Geology/soils: 

Sandy and other soils underlain by Weber Sandstone, Park 

City, and other formations. Plant communities: Big sagebrush, black sagebrush, mountain brush, ponderosa pine, 

Douglas-fir, pinyon-juniper. Notes: This plant grows in 

shade of pinyon and juniper and some tolerance of pinyonjuniper cover is evident. However, it is found in vigorous 

form outside duff and shade associated with these trees. Its 

abundance in black sagebrush and mountain brush communities indicates no obligatory relationship with pinyon or 

juniper. 

262 

Lepidium barnebyanum Reveal Barneby peppergrassGeology/soils: White shale outcrops of the Uinta Formation where most common on ridge crests. Plant communities: Pinyon-juniper and mound plant communities. Notes: 

Although known from within the pinyon-juniper belt, the 

plant is most common on ridge crests where semibarrens or 

mound plant communities have developed in sparse or open 

pinyon-juniper communities. Presence of this plant in open 

pinyon-juniper but not closed pinyon-juniper communities 

indicates tolerance of pinyon-juniper presence but intolerance of crown closure of these trees. 

Lesquerella tumulosa (Barneby) Reveal Kodachrome 

bladderpod-Geology/soils: White, bare shale knolls of 

Winsor Member of the Carmel Formation. Plant Communities: Among scattered juniper in a gramma grassland. 

Notes: While this species seems to be correlated with geologic strata, it is only found amongst scattered juniper. 

Typical habitat is bare shale knolls where any other vegetation is quite uncommon. While most often found in the bare 

inner spaces between juniper, plants are also be found 

directly in duff under the canopy ofindividual trees. Growth 

of individual plants does not seem to be influenced by 

presence or absence of duff and/or canopy. 

Pediocactus despainii Welsh Despain footcactus-Geology/soils: Limestone gravels. Plant communities: Open 

pinyon-juniper. Notes: The distribution of this species being 

largely limited to within the pinyon-juniper belt might 

indicate a positive relationship to these trees. This species is 

found scattered within pinyon-juniper communities. However, it does not seem to be dependent on either of these tree 

species. It is often found in open, unvegetated spaces, on 

gravelly substrate. It is not found in thick canopy cover, nor 

directly under canopy of woody species. A negative relationship is indicated for pinyon-juniper canopy closure. 

Pediomelum epipsilum (Barneby) Welsh Kane breadrootGeology/soils: Chinle and Moenkopi Formations. Plant 

communities: Sparse sagebrush and pinyon-juniper Notes: 

This species occurs with sparse sagebrush and pinyonjuniper. It often found growing in desert pavement within 

the open spaces of pinyon-juniper. This hardy species has 

also been observed growing through eroding highway gravels. Decline in numbers of this species has been concurrent 

with loss ofpinyon-juniper. While no definite relationship is 

known to exist, there is an indication that this species 

survives best in pinyon-juniper openings. 

Penstemon atwoodii Welsh Atwood penstemon-Geology/soils: Kaiparowits, Wahweap, and Straight Cliffs Formations on grayish sand and clay loam soils. Plant communities: Ponderosa pine and pinyon-juniper. Notes: Presence 

of this species in both ponderosa pine and pinyon-juniper 

indicates no obligatory relationship to either one. However, 

with its range essentially limited to pinyon-juniper and 

ponderosa pine communities a positive relationship to these 

trees is indicated. 

Penstemon bracteatus Keck. Red Canyon beardtongue or 

platy penstemon-Geology/soils: Pink and white limestone members ofthe Wasatch Formation. Plant communities: Ponderosa pine, pinyon-juniper, limber pine, and 

bristlecone pine-manzanita. Notes: This species is found 

within exposed strata of the Wasatch Formation. It 

commonly occurs in sparsely vegetated areas within many 

different woody communities. It does not seem to 

USDA Forest Service Proceedings RMRS-P-9. 1999 
demonstrate an obligatory relationship with anyone of 

these tree covered communities, but it is geologically selective. However, a secondary relationship to trees is indicated 

by the distribution being essentially limited to tree covered 

communities. 

Penstemon concinnus Keck. Elegant penstemon or Tunnel 

Springs beardtongue-Geology!soils: Calcareous or igneous gravels usually of pale limestone parent materials. 

Plant communities: Pinyon-juniper and sagebrush. Notes: 

This species commonly occurs within a moderate canopy 

cover of pinyon-juniper and does not seem deterred by the 

presence of duff or litter. It is most often not found directly 

under canopy of pinyon-juniper, but within the small inner 

spaces between trees. However, canopy cover is not a deterrent to its occurrence. In rare circumstances it can be found 

in sagebrush communities at the edge of pinyon-juniper 

communities. 

Townsendia aprica Welsh & Reveal Last chance 

townsendia-Geology!soils: Clay or clay silt soils ofArapien 

and Mancos Shale Formations. Plant communities: Salt 

desert shrub and pinyon-juniper. Notes: This species is 

most commonly found within the pinyon-juniper belt where 

it occurs in open to moderately dense cover. Although it does 

grow directly under pinyon -j uni per, it is just as easily found 

in vast open areas within the pinyon-juniper belt. A positive 

relationship between tree cover, duff, or other habitat feature that is a function of pinyon-juniper is not apparent. 

Incidental 

Aquilegia barnebyi Munz Shale columbine-Geology! 

soils: Semibarren slopes, ridges, cliffs, ledges, and talus of 

Douglas creek and Parachute members of the Green River 

Formation and Uinta Formation. Plant communities: 

Mixed desert shrub, Salina wildrye, pinyon-juniper, Douglas-fir. Notes: This is a plant of open sites. It is not favored 

by shade nor duff or any other microsite feature that is a 

function of pinyon or juniper. It's association with these 

trees is incidental to its affinity for the Green River and 

Uinta Formations. It's independence from habitat features 

that are a function of pinyon or juniper is verified by its 

abundance in mixed desert shrub and Salina wildrye communities and by populations of high numbers on high elevation, wind swept ridges beyond the influence of pinyon and 

juniper. 

Astragalus chloodes Barneby Grass milkvetch-Geology!soils: Outcrops of Entrada, Navajo, Frontier, Dakota, 

and other sandstone hogbacks and cuestas. Plant Communities: Mixed desert shrub, mountain brush, and pinyonj uni per. Notes: A strong propensity for sandstone barrens in 

full sun without litter or shade indicates the association of 

this species with juniper is incidental. The association is a 

function of the ability of pinyon-juniper to tolerate sandstone barrens and the propensity of this species for these 

barrens. 

Astragalus hamiltonii C. L. Porter Hamilton milkvetchGeology!soils: Heavy clay soils and road cuts in the 

Duchesne River and perhaps Wasatch Formations. Plant 

communities: Road cut, sparsely vegetated desert shrub 

and juniper. Notes: This uncommon plant is often favored 

by road cuts where robust specimens produce abundant 

flowers and fruit. It is found on badlands of inherently high 

USDA Forest Service Proceedings RMRS-P-9. 1999 

erosion rates in full sun. Associated vegetation is sparse. 

There is no indication this species is favored by shade or duff 

or any other habitat feature that could be a function of 

pinyon or juniper. Indeed the distribution of this species 

indicates it would be adversely effected by increasing density ofthese trees. The association of this plant with juniper 

and perhaps rarely with pinyon is a function of the ability of 

these trees to occupy the badlands of the Duchesne River 

Formation to which this plant has a strong affinity. The 

inference by Davidson and others (1996) that this plant 

would be favored by wilderness status (designated wilderness as an act of congress) demonstrates a misconception of 

many narrow endemic plants which are well adapted to 

disturbance. The propensity of A. hamiltonii, A. saurinus, 

Eriogonum viridulum, and many other endemic species for 

road cuts, roadsides, and other disturbance does not support 

the concept that wilderness status is necessary or even 

helpful for the perpetuity of many of these plants. 

Astragalus iselyi Welsh Isely milkvetch Geology!soils: 

Heavy clay derived from shale members ofthe Morrison and 

Paradox Formations. Plant communities: Salt desert 

shrublblackbrushlgreasewood and Utahj uni per!galleta grass 

communities. Notes: This plant is widely scattered around 

the LaSal Mountains where it seems to be more restricted by 

the geological strata on which it grows than by plant type 

association. 

Astragalus lutosus Jones Dragon milkvetch-Geology! 

soils: Green River Shale barrens. Plant communities: 

Desert shrub, mountain brush, limber pine, Douglas-fir, 

pinyon-juniper. Notes: Although reported for the above 

communities, this plant is one of barrens where pinyon, 

juniper, and other trees occur as scattered individuals. The 

affinity of this species for the Green River Shale is evident 

across a wide elevational range from 1,570 to 2,870 m (5,150 

to 9,400 ft). That the range of the species includes elevations 

both below and above the pinyon-juniper belt demonstrates 

no obligatory relationship with these trees. The strong 

affinity for geologic substrate indicates little or no response 

of this species to habitat conditions that could be a function 

of pinyon or juniper. Association of pinyon and juniper with 

this plant is a function of the common ability ofthese plants 

to occupy this harsh substrate. In the case of Astragalus 

lutosus, the geology is obligatory. In the case of pinyon and 

juniper, this substrate isjust one of many that these species 

tolerate. 

Perhaps as well as any Utah endemic specialist, the 

Dragon milkvetch demonstrates an affinity for specific geologic strata. This plant is known from Rio Blanco County, 

Colorado to Utah County, Utah on the Tavaputs Plateau 

where it is most common in the White River drainage 

including the Pieance Basin and Two Waters drainage. The 

total range of the species is over 200 km long. Toward the 

west, known populations are isolated and separated by as 

many as 50 km. These isolated population are found on 

barrens or semi barrens of exposed Green River Shale. No 

population of this plant is known from this or any other 

substrate where the geologic strata is well mantled by 

vegetation. 

Astragalus pattersonii Gray ex Brand. Patterson 

milkvetch-Geology!soils: Seleniferous soils of Blue 

Gate member of the Mancos Shale Formation and other 

formations that tend to weather to badlands. Plant 

263 
communities: Mixed desert shrub, pinyon-juniperlblack 

sagebrush/galleta grass. Notes: This plant is sometimes 

found under shade of juniper and other overstory plants. Its 

presence in mixed desert shrub communities does not 

indicate an obligatory relationship with pinyon or juniper. 

However, its presence in shade of overs tory indicates tolerance or perhaps a beneficial relationship. 

Cryptantha brevifolia (Osterh.) Payson Short-flower 

cryptanth-Geology/soils: Mostly heavy clay soils of the 

Morrison and Duchesne River Formations. Plant communities: road-cut, salt desert shrub, sagebrush, rabbitbrush, 

pinyon-juniper, mountain brush Notes: The presence ofthis 

species in desert shrub and road-cut communities where it 

is found in full sun indicates no obligatory relationship with 

pinyon-juniper. Where it is found with pinyon-juniper, the 

trees are mostly scattered and oflittle influence on habitat 

conditions. 

Cryptantha creutzfeldtii Welsh Creutzfeldt-flower-Geology/soils: Seleniferous soils of Mancos Shale. Plant communities: Mat saltbush and scattered Utah juniper/salina 

wildrye. Notes: This plant is restricted by geologic substrate. Its presence in mat saltbush communities indicates 

shade, duff, or other habitat feature that is a function of 

Utah juniper is not critical to the species. 

Erigeron maguirei Cronq. Maguire daisy-Geology/soils: 

Rocky canyon bottoms of Wingate and Navajo sandstone, 

rim rock and other slick rock of Navajo sandstone Plant 

communities: Mountain brush, pinyon-juniper, ponderosa 

pine, and Douglas-fir. Notes: No specific associations occurs 

with any plant community. Plants occur on open windswept 

outcrops and under shaded canopy within deep canyon 

bottoms. Al though associated with pinyon -j uni per, this plant 

is quite limited to cracks and crevices in rock outcrops. The 

association with pinyon-juniper is indicated to be incidental. 

Gilia caespitosa Gray Rabbit Valley gilia-Geology/soils: 

Carmel and Navajo Formations. Plant communities: Pinyon-juniper. Notes: This species occurs in crevices, sand, 

and open rocky outcrops associated with Navajo Sandstone. 

Other vegetation is sparse aI}d includes ponderosa pine. 

Known populations are from semibarrens where there is no 

indication of obligatory relationship with pinyon-juniper. 

Lomatium latilobum (Rydb.) Mathias Canyonlands 

lomatium or broad-leafed biscuitroot-Geology/soils: 

Mainly on Entrada Sandstone and N avaj 0 Sandstone on fine 

textured loose sand. Plant communities: Pinyon-juniper/ 

BlackbrushlIndian ricegrass, Pinyon-juniper/Mixed mountain brush/Needlegrass and desert shrub. Notes: Plants are 

mostly found in crevices of rock and on sandy deposits. 

Although found within pinyon-juniper woodlands, they are 

more common on open exposed, sunny (hot) sites where 

there is no indication that they are dependent on pinyonjuniper. 

Penstemon grahamii Keck in Graham Graham penstemon-Geology/soils: White to tan semi-barren, shaley 

slopes, ridges and knolls of the Parachute member of the 

Green River Formation. Plant communities: Shadscale, 

greesebush, Salina wildrye, and pinyon-juniper. Notes: 

Habitat affinity for this species is exposed geologic strata 

with comparatively little soil development. Presence in 

shrub and grass communities indicates no dependency on 

shade or duff or other habitat feature that is a function of 

pinyon-juniper. Where associated with pinyon-juniper, the 

264 

trees are scattered. It is not found in stands of trees with 

moderate or high crown closure indicating tolerance of 

limited presence of these trees but intolerance of crown 

closure or intolerance for soil conditions that allow for 

closure of pinyon-juniper canopy. 

Penstemon idahoensis Atwood & Welsh Idaho penstemon-Geology/soils: Barrens, semi-barrens, and road cuts 

in white tuffaceous outcrops. Plant Communities: Sagebrush and scattered juniper. Notes: Habitat propensity of 

this species is for exposed tuffaceous materials. Association 

with juniper is incidental and a function of juniper to 

tolerate this material as well as nearly every exposed geologic strata within the pinyon-juniper belt of Utah. 

Phacelia argillacea Atwood Clay phacelia-Geology/soils: 

Semi-barrens ofthe Green River Formation. Plant communities: Rocky mountain juniper/Gambel oak sites Notes: 

Although within the range of the pinyon-juniper belt, this 

plant is not dependent on or obligate to pinyon-juniper. It is 

in no way associated with the trees. It is found on open, 

actively eroding Green River Shale slopes with only limited 

vegetation. This species does not do well in competition with 

any other vegetation. 

Spiranthes diluvialis Shev. Ute lady's tresses-Geology! 

soils: Moist to wet soils of wetlands and riparian areas. 

Plant communities: Riparian, meadow, wetland areas 

within cottonwood, tamarix, willow, and pinyon-juniper 

communities. Notes: This species is obligate to moist soils of 

riparian or wetland communities. The association with 

pinyon-juniper is accidental, and the listing of this species 

for pinyon-juniper communities is mostly based on riparian 

inclusions within the pinyon-juniper belt. However, the 

ecological amplitude of pinyon-juniper includes riparian 

settings. Ute lady's tresses is more common in open grass 

and forb dominated communities than where shrub and tree 

density or canopy closure is high. A negative relationship is 

indicated for this species with pinyon-juniper crown closure. 

Talinum thompsonii Atwood & Welsh Thompson talinumGeology/soils: Silicious conglomeratic gravels of the North 

Horn Formation. Plant communities: Pinyon-juniper/ 

cliffrose/needlegrass, pinyon-juniper/alder-leaf mountainmahogany/Salina wildrye. Notes: The most vigorous populations of this plant occur in the cracks and crevices of the 

conglomerate rock outcrops without pinyon-juniper cover 

which is primary habitat for the species. A small population 

occurs in a dense stand of mature pinyon-juniper trees with 

an understory of crytograms which is marginal habitat. 

Summary List of Taxa _____ _ 

A list of taxa for each of these categories without discussion is provided below. For brevity neither authors nor 

common names are given in these lists. For the most part, 

nomenclature follows that of Welsh and others (1993) and 

Atwood and others (1991) where authors and common names 

are provided. 

Obligatory or Semiobligatory 

These plants are found in shade and/or duff of pinyonjuniper more commonly than not, and they appear to be 

USDA Forest Service Proceedings RMRS-P-9. 1999 
either dependent upon or at least greatly favored by habitat 

features that are a function of pinyon and/or juniper. 

Arabis vivariensis 

Camissonia exilis 

Echinocereus triglochidiatus var. inermis 

Penstemon pinorum 

Apparent Associates 

These plants are known only, or mostly, from within 

pinyon and/or juniper communities but are mostly found in 

inner spaces of the trees and often on exposed geologic 

substrate where substrate more than trees could be the 

habitat feature these plants respond to most. 

Allium geyeri var. chatterlyi 

Astragalus desereticus 

Cryptantha jonesiana 

Draba pectiniphila2 

Lepidium barnebyanum 

Lesquerella tumulosa 

Pediocactus despainii 

Pediomelum epipsilum 

Penstemon atwoodii 1 

Penstemon bracteatus1 

Penstemon concinnus 

Townsendia aprica 

Trifolium friscanum 

1 Although known from other tree dominated communities, this is mostly known 

where trees are present, and it could be positively related to pinyon-juniper as well 

as other trees. 

2Although known from habitats without pinyon-juniper, this plant appears to do 

well under pinyon-juniper. Although not necessary for the plant, habitat created 

by pinyon-juniper is favorable to the plant. 

Incidental 

These are species known from within the pinyon-juniper 

belt, but which also extend below the belt into salt desert 

shrub communities or above the belt and often to open wind 

swept slopes and ridges of exposed geology where geology is 

clearly the feature to which these species respond. Their 

association with pinyon and/or juniper is incidental and 

often a function of the ability of pinyon andjuniperto inhabit 

a broad range of exposed geological strata without substantially modifying the environment of the exposed strata. 

Aquilegia barnebyi 

Artemisia nova var. duchesnicola 

Asclepias cutleri 

Asclepias welshii 

Aster kingii var. barnebyana 

Astragalus ampullarius 

Astragalus anserinus 

Astragalus barnebyi 

Astragalus chloodes 

Astragalus coltonii var. moabensis 

Astragalus consobrinus 

Astragalus duchesnensis 

Astragalus eastwoodii 

Astragalus equisolensis 

Astragalus hamiltonii 

Astragalus henrimontanensis 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Astragalus iselyi 

Astragalus lutosus 

Astragalus monumentalis 

Astragalus musiniensis 

Astragalus oophorus var. lonchocalyx 

Astragalus pattersonii 

Astragalus saurinus 

Astragalus serpens 

Astragalus subcinereus var. basaltic us 

Cirsium ownbeyi 

Chrysothamnus nauseosus var. uintahensis 

Cryptantha brevifolia 

Cryptantha cinerea var. arenicola 

Cryptantha creutzfeldii 

Cry ptantha johnstonii 

Cryptantha ochroleuca 

Cryptantha paradoxa 

Cryptantha witherillii 

Cycladenia humilis var.jonesii 

Cymopterus beckii 

Cymopterus coulteri 

Cymopterus duchesnensis 

Draba kassii 

Epilobium nevadense 

Erigeron maguirei 

Erigeron untermanii 

Eriogonum aretioides 

Eriogonum batemanii var. eremicum 

Eriogonim batemanii var. ostlundii 

Eriogonum brevicaule var. ephedroides 

Eriogonum brevicaule var. viridulum 

Eriogonum corymbosum var. cronquistii 

Eriogonum soredium 

Festuca dasyclada 

Gilia caespitosa 

Gilia stenothyrsa 

Gilia tenuis 

Gutierrezia pomariensis 

Hedysarium occidentale var. canone 

Hymenoxys acaluis var. nana 

Hymenoxys lapidicola 

Lepidium montanum var. stellae 

Lepidium ostleri 

Lomatium latilobium 

Lygodesmia grandiflora var. entrada 

Mentzelia argillosa 

Mentzelia goodrichii 

Mentzelia multicaulis var. librina 

Mentzelia multicaluis var. multicaluis 

Oreoxis trotteri 

Pediocactus winkleri 

Pediomelum pariense 

Penstemon acaulis var. acaulis 

Penstemon amrrwphilus 

Penstemon angustifolius var. dulcis 

Penstemon duchesnensis 

Pensternon fremontii 

Penstemon goodrichii 

Penstemon grahamii 

Penstemon idalzoensis 

Penstemon nanus 

Penstemon pachyphyllus 

265 
Penstemon parvus 

Penstemon scariosus var. albifluvis 

Penstemon tidestromii 

Penstemon wardii 

Phacelia argillacea 

Selaginella utahensis 

Schoencranbe suffrutescens 

Sclerocactus pubispinus var. pubispinus 

Sclerocactus wrightiae 

Silene petersonii 

Sphaeralcea caespitosa 

Spiranthes diluvialis 

Talinum thompsonii 

Thelesperma subnudum var. alpinum 

Thelesperma subnudum var. caespitosum 

Townsendiajonesii 

Townsendia mensana 

Xylorhiza cronquistii 

Discussion _________ _ 

Many of the narrow endemic plants of Utah including 

those of the pinyon-juniper belt are found on semibarrens 

or badlands where geologic strata are exposed or on wind 

deposited sands. These relationships are repeated in so 

many taxa that it is apparent that these plants have 

evolved where geology and erosion are primary drivers of 

plant community composition and dynamics. Chemical and 

water relations are closely allied to geological formations. 

Ecology of most endemic plants of Utah indicate an inability of these plants to occupy well-developed soils, inability 

to compete for resources with the generalists that are 

commonly found there, or they are suppressed by shading 

of shrubs and trees (comparatively few endemic plants of 

Utah are shrubs and none are trees). The implication is 

strong that the open sites of harsh substrates and special 

conditions provide opportunities for development for specialists that have not developed the ability to compete with 

aggressive generalists. Aggressiveness of generalists such 

as pinyon andjuniper is evident in the wide range of these 

species and the super dominance (West and Van Pelt 1987) 

they are ca pable of expressing. Even on sites w here endemics 

are the most common plants, plant density often remains 

low. Here survival appears more a function of adaptation to 

harsh substrates and dry conditions than an ability to 

compete with other plants. 

Colorado pinyon, singleleaf pinyon, and Utah juniper 

each have a broad ecological amplitude, and they are 

capable of colonizing on all, or nearly all, exposed geologic 

strata within their thermal belt. However, their presence 

on many of these substrates is often limited to depauperate, 

scattered individuals that are obviously stressed by the 

harsh conditions where they do little to modify the environment. Such harsh environments are open to colonization by 

narrow endemic specialists. In contrast to the depauperate 

and stressed nature of generalists that do exist on these 

harsh sites, many of the specialists flower and fruit in 

profusion with appropriate timing and amounts ofprecipitation, and they have developed mechanisms which enable 

them to survive through times without favorable moisture. 

Layers of alluvium, which represent mixtures of mater ials from different sources tend to insulate vegetation from 

266 

peculiar chemical and water relations of exposed geologic 

strata (Welsh 1979). With increasing depth of alluvium and 

increasing soil profile development, conditions become increasingly favorable for plant growth and greater productivity. Generalists such as big sagebrush, Colorado pinyon, 

Utahjuniper, and common widespread grasses occupy such 

sites. Here competition among different species and among 

individual plants drives plant community dynamics where 

the most aggressive species express high percent crown 

cover in the absence of disturbance. In such highly competitive environments, most narrow endemic specialists are 

excluded. 

A concept of dependency on pinyon or juniper for narrow 

endemic specialists is contrary to the concept of specialization. The propensity of narrow endemic specialists for open 

sites in contrast to the paucity of occurrences within pinyon-juniper communities with high crown closure supports 

the concept of specialization on open habitats and not 

dependency on pinyon or juniper. The occurrence in desert 

shrub communities of many of the narrow endemics that 

are reported for pinyon-juniper communities is additional, 

and quite conclusive, evidence that many of these taxa are 

not dependent on shade, duff, or any other habitat feature 

that is a function of pinyon or juniper. 

The coexistence of Colorado pinyon and Utah juniper 

with narrow endemic specialists throughout Utah is evidence of the potential of pinyon and juniper to occupy or at 

least exist on nearly all (if not all) exposed geologic strata 

within their thermal belt. Their general occurrence on 

alluvial surfaces within their thermal belt is additional 

evidence of their broad ecological amplitude. These highly 

competitive species, which are capable of near complete 

dominance on many sites and which can effectively eliminate such highly competitive species as sagebrush and 

perennial grasses, can hardly be expected to be nurse 

plants for many narrow endemic specialists. 

This concept is supported by the few species listed by 

Atwood and others (1991) for aspen communities of Utah. 

Ofthe seven species listed for aspen, five are indicated to be 

specific for rocky open places. Botanical collections from 

sagebrush communities are mostly not specific to the dominant sagebrush taxon at a site. Thus, it is not possible to 

compare endemic plants with habitat as indicated by different sagebrush taxa. However, it is the experience of t~e 

authors that relatively few endemic species are found III 

mountain big sagebrush communities, which tend to be on 

Mollisols. Relatively few are found in Wyoming big sagebrush communities with high crown closure. A greater 

number seem to be associated with black sagebrush, which 

indicates less favorable conditions for plant growth. 

In general, endemic plants are few on soils ofthe Mollisol, 

Alfisol or other orders indicating high degree of soil profile 

develo~ment. Many endemic species are found on cliff 

faces, talus slopes, and semibarrens of exposed geologic 

strata where soils of the Inceptisol and Entisol Orders are 

indicated. 

The harsh exposed unfavorable habitats presented by 

exposed geologic strata under xeric conditions provide ~ 

refuge for narrow endemic specialists against the competItive and often dominating influence of pinyon and juniper. 

With the exceptions of four species listed above as obligatory or semiobligatory and the possible exceptions of 

USDA Forest Service Proceedings RMRS-P-9. 1999 
14 species listed above as apparent associates, a neutral or 

negative relationship with pinyon-juniper crown closure is 

suggested for most narrow endemic species of the pinyonjuniper thermal belt of Utah. Of the 14 apparent associates, 

woods draba and a few other species show considerable 

tolerance to pinyon-juniper cover without being dependent 

on pinyon-juniper cover. For these species a negative or 

positive relationship is not clear. 

Management Implications ___ _ 

The nature of narrow endemic specialists to occupy 

semibarren habitats indicates low potential for vegetation 

manipulation projects on these sites. Indeed, the presence 

of many of these species could be used as an indicator oflow 

potential. However, the more obvious barren nature of 

many of their habitats should be indicator enough that 

these are not appropriate sites for forage improvement 

projects. There are a few exceptions, and generalized conclusions are not an appropriate substitute for specific surveys and specific data bases for local areas. However, from 

data available in 1979, Welsh (1979) concluded it was 

possible to prepare a model with predictive capability that 

could aid in the search for these plants. Information gained 

since 1979 supports this concept. Sites with alluvial soils or 

where soil profiles are well developed, or where dense 

stands of pinyon-juniper with high percent canopy closure 

are present are indicated to be better sites for projects for 

high production of shrubs and herbaceous species. These 

habitats provide sites for such projects with low potential 

for narrow endemic plants. 

Distribution of rare species is not equal. Certain areas 

appear to lack them while other areas support concentrations of several species. Unless a specific mineral to be 

exploited is located within an outcrop that supports one or 

more narrow endemic species, or unless the area to be 

occupied by a particular development is large, there seems 

little reason why activities should impress known endangered or threatened plant species. Even in these two exceptional instances there should be opportunity for mitigation. 

The best site for industrial development is not always the 

only good alternative (Welsh 1979). In some cases, narrow 

endemic plants ofthreatened or endangered status do come 

into conflict with development. An example is the low 

bearclaw-poppy (Arctomecon humilis Cov.) and urban development in and around the city of St. George, UT, where 

economic values for semibarrens or badlands are high. 

Such economic val ues are driven by urban development. No 

such value is indicated for cultural practices such as burning or chaining for forage or watershed improvement 

projects. The nature of the habitat should serve to protect 

many of these plants from these kinds of projects. The 

remainder can be addressed and protected by referring to 

well-documented inventories. Where such inventories are 

lacking, management should place high priority for achieving such inventories. 

The habitat for many narrow endemic specialists might 

be considered at less than desired condition because oflow 

production or high rates of erosion and delivery of salts to 

rivers. This might be suspected to be a function of use of the 

land by non-Native Americans and their livestock. 

However, the strong relationship between highly erosive, 

USDA Forest Service Proceedings RMRS-P-9. 1999 

exposed geologic strata and narrow endemic specialists 

indicates an evolutionary ecology dependent on harsh conditions and high rates of erosion that predates the advent 

of European settlers and their livestock by thousands of 

years. 

The comparatively rare nature of these plants indicates 

their high value for biodiversity and for the study of speciation, evolutionary biology, reproductive ecology, biogeography, taxonomy, species interactions and species rarity 

(Heil and Melton 1995). Additionally some of these plants, 

such as the several penstemons, contribute to aesthetics of 

semibarren landscapes. Some have potential for flower 

gardens. Also some, such as the Duchesne buckwheat 

(Eriogonum brevicaule var. viridulum [Reveal] Welsh), 

offer some potential to greatly soften the visual aspects of 

road cuts. 

Maintenance of these plants is dependent on semibarrens 

or badlands with high rates of erosion and sometimes high 

delivery of salts. Attempts to alter these habitats by structures or establishing highly competitive plants that are 

capable of slowing erosion can be expected to have a high 

rate of failure. Any such project that might be successful 

would likely be highly detrimental to narrow endemic 

plants present in the project area. 

As dense pinyon-juniper stands develop on sites, ground 

cover is often red uced as a function of bearing of inters paces 

where rill and sheet erosion increase with increasing pinyon-juniper cover. This relationship might be suspected of 

creating habitat for narrow endemic specialists that are 

often favored by erosion and bare surfaces. However, this is 

not indicated to be a major source of habitat for narrow 

endemics. Sites favorable enough for pinyon and juniper to 

achieve high cover are not indicated to be sites of evolutionary development of many rare species. Dense cover ofthese 

species is indicative of plant competition far beyond the 

tolerance of many narrow endemic specialists. 

A concept labeled "properly functioning condition" is 

currently of high profile in some Federal agencies. Under 

this concept, narrow endemic plants and the badlands on 

which they have evolved present some different values to 

consider compared to those of landscapes that have the 

potential to be well mantled by vegetation. One of the 

functions of badlands in Utah is production of narrow 

endemic plant specialists including most of those listed as 

threatened and endangered. The evolutionary ecology of 

these plants indicate these badlands have been so for 

thousands of years. They have been highly erosive. They 

have contributed salts to drainage. These are inherent 

functions of these lands. Difficulty in applying the term 

"proper function" to this scenario demonstrates values of 

questionable application to badlands or semibarrens where 

geologic strata are exposed or where they are near the 

surface or where xeric conditions prevent development of 

dense vegetative cover. 

Inherently highly erosive geologic substrates are well 

accepted as national treasures inside National Parks. There 

are reasons to accept these conditions as inherent on lands 

administered by other agencies. Narrow endemic plants 

are one of those reasons. Indeed production of these plants 

should be a measure of proper function. 

There seems to be a tendency for those opposed to handson management of pinyon-juniper ecosystems to look at 

267 
threatened and endangered species as a reason to stop 

projects designed to manage vegetation. Also, it seems 

those who support practices used to manage vegetation 

sometimes demonstrate an attitude of resentment toward 

threatened and endangered plant species. Neither of these 

attitudes seem appropriate for narrow endemic plants of 

Utah. Holmgren (1979) advised against taking a strong 

stand pro or con without sufficient knowledge. He also 

warned against advocacy for preservation by those who 

might view these plants mainly as instruments for political 

strategy. In view of the value of these rare or restricted 

plants and in view of the laws and regulations dealing with 

some ofthem, continued botanical surveys that lead to welldocumented inventories are appropriate. Planning and 

management based on such inventories also seem appropriate. In the case ofpinyon-juniper,5t seems highly likely 

that most potential conflicts between vegetation management and narrow endemic plants can be rather easily 

resolved with well-documented inventories and an understanding of the habitat and biology of these species. 

Using geologic maps, recognizing geologic strata, recognizing soils that tend to repel water and are inherently 

sparsely vegetated can facilitate inventory for many of 

these plants. 

References __________________ __ 

Atwood, N. D. 1979. Management programs for plants on Federal 

lands. Great Basin Nat. Memoirs. 3: 81-85. 

Atwood, N. D.; Holland, J.; Bolander, R. and others. 1991. Utah 

threatened, endangered, and sensitive plant field guide. Ogden, 

UT: U.S. Department of Agriculture, Forest Service, Intermountain Region. 1 vol. 

Davidson, D. W.; Newmark, W. D.; Sites, J. W. Jr.; and others. 1996. 

Selecting wilderness areas to conserve Utah's biological diversity. Great Basin Nat. 56: 95-118. 

Fertig, W. 1995. Status report on Thelespema cespitosum)n southwestern Wyoming. Cooperative Agreement # K910-4A-0011. 

Laramie, WY: Wyoming Natural Diversity Data Base. 45 p. 

Fertig, W.; Refsdal, C.; Whipple, J. 1994. Wyoming rare plant field 

guide. [Place of publication not givenl. The Wyoming Rare Plant 

Technical Committee. [Pages not numberedl. 

Franklin, M. A. 1989. Target species: Erigeron untermannii Welsh 

& Goodrich (Untermann daisy). Report for 1990 Challenge Costshare Project, Ashley National Forest. Salt Lake City, UT: Utah 

Natural Heritage Program. 9 p. with appendices. 

Franklin, M. A. 1992. Target species: Penstemon acaulis. Report of 

1992 Cost-share Project Ashley National Forest. Salt Lake City, 

UT: Utah Natural Heritage Program. 11 p. with appendices 1-5. 

Franklin, M. A. 1993. Report for 1992 joint challenge cost share 

project Ashley National Forest and Section Six Agreement, U.S. 

Fish and Wildlife Service, target species: Ute ladies'-tresses 

(Spiranthes diluuialis) Sheviak. Salt Lake City, UT: Utah Department ofN atural Resources, Utah Natural Heritage Program. 

22 p. with appendices. 

268 

Goodrich, S. 1981. A floristic study on central Nevada. Provo, UT: 

Brigham Young University. 400 p. Thesis. 

Goodrich, S. 1984. Checklist of vascular plants of the Canyon and 

Church Mountains. Great Basin Nat. 44: 277-295. 

Goodrich, S. 1986. Vascular plants of the desert experimental 

range, Millard County, Utah. Gen. Tech. Rep. INT-209. Ogden, 

UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 72 p. 

Goodrich, S.; Neese, E. 1986. Uinta Basin Flora. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Intermountain Region. 320 p. 

Harper, K. T. 1979. Some reproductive and life history characteristics of rare plants and implications of management. Great Basin 

Nat. Memoirs. 3. 

Hei!, K. D.; Melton, B.1995. Status reports for Astragalus hamiltonii 

C. L. Porter, Penstemon flowersii Neese and Welsh, and Penstemongoodrichii N. Holmgren. Farmington, NM: Kenneth D. Heil. 

3 reports. 

Holmgren, A. H. 1979. Strategies for preservation of rare plants. 

Great Basin Nat. Memoirs. 3: 95-99. 

Neese, E.; Smith, F. 1982. Threatened and endangered plant inventory for the oil shale RMP, Bookcliffs Resource Area, Bureau of 

Land Management, Vernal District. Unpublished report on file 

at: Vernal District Office, Bureau of Land Management, Vernal, 

UT. 5 Vol. [Prepared by BiolWest Inc., Logan, UT]. 

Peterson, J. S.; Baker, W. L. 1982. Inventory of the Piceance Basin, 

Colorado; threatened and plants, plant associations, and the 

general flora. Unpublished report on file at: Craig District Office, 

Bureau of Land Management, Craig, CO. 5 vol. [Prepared by 

Colorado Natural Heritage Inventory, Denver, Co.]. 

Shultz, J. S. 1982. Report on the search for rare and endangered 

plant species in the Uinta Basin of Utah on Quintana Minerals 

Corporation Land Holdings. Unpublished report on file at: Vernal 

District Office, Bureau of Land Management, Vernal UT. 54 p. 

[Prepared by Western Wildland Resources, Logan, UTl. 

Shultz, L. M.; Mutz, K. M. 1979. Threatened and endangered plants 

of the Willow Creek drainage. Unpublished report on file at: 

Vernal District Office, Bureau of Land Management, Vernal, UT. 

2 vol. [Prepared by Meiiji Resource Consultants, Bountiful, UT.l 

U.S. Department of Agriculture Forest Service. [n.d.]. Idaho and 

Wyoming endangered and sensitive plant field guide. Ogden, UT: 

U.S. Department of Agriculture, Forest Service, Intermountain 

Region. 192 p. 

U.S. Department of Agriculture Forest Service. 1991. Humbolt 

National Forest sensitive plant field guide. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Intermountain Region. [Pages not numberedl 

Welsh, S. L. 1957. An ecological survey of the vegetation of the 

Dinosaur National Monument, Utah. Provo, UT: Brigham Young 

University. 65 p. Thesis. 

Welsh, S. L. 1978. Problems in plant endemism on the Colorado 

Plateau. Great Basin Nat. Memoirs. 2:191-195. 

Welsh, S. L. 1979. Endangered and threatened plants of Utah: A 

case study. Great Basin Nat. Memoirs 3: 69-80. 

Welsh, S. L.; Atwood, N. D.; Goodrich, S.; Higgins, L. C. 1991. A Utah 

Flora. Provo, UT: Brigham Young University Print Services. 986 p. 

West, N. E; Van Pelt, N. S. 1987. Successional patterns in pinyonjuniper woodlands. In: Everett, R. L. compiler. Proceedingspinyon-juniper conference; 1986 January 13-16; Reno, NV: Gen. 

Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station: 43-52. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
269 

Ecological 

Restoration 

Ecology and Management of Pinyon-Juniper 

Communities Within the Interior West: 

Overview of the "Ecological Restoration" 

Session of the Symposium 

Robert B. Campbell, Jr. 

Abstract-Restoration of pinyon and juniper landscapes is a complex subject. Notable strides made during the past decade provide 

information to restore many sites. An array of treatments and plant 

materials are available for restoration of-a variety of sites and plant 

associations. Restoration will not be successful without commitment and proactive treatments on a broad scale. This session 

included oral papers, poster presentations, and portions of an 

informative field trip. 

I summarize the 29 presentations from the "Ecological 

Restoration" session of the conference. This summary highlights significant concepts and weaves together themes 

frequently shared in many of the presentations. With two 

exceptions, the references cited are found in this proceedings 

or were presented at the conference. This synthesis also 

includes information presented on the field tour and a few 

poster presentations not printed in the proceedings. 

In the context ofthis session, ecological restoration means 

restoring the community balance of native species that 

existed prior to European settlement and reinstituting succession complete with historical functions and processes 

(Monsen). Emphasis should be to favor, if still present, or 

reintroduce the species that were historically present. In 

contrast, McArthur and Young explained that rehabilitation implies a renewal of land productivity but with an 

associated change in the composition and structure of the 

ecosystem. 

I synthesized the themes and concepts from this session's 

papers in the following general areas: 

1. Site selection (historical cover types and objectives and 

guidelines) 

2. Treatments (chaining, fire use, chemical control, rollerchopping, and harvests) 

3. Species composition and selection (native and introduced species, seed mixes and stockpiling, weed control, and 

seed certification). 

I offer a reaction to the chaining demonstration, followed 

by a discussion of new information, management implications, prioritizing potential treatment areas, and the "land 

ethic and ecological conscience." 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Robert B. Campbell, Jr. is ecologist, USDA Forest Service, Fishlake 

National Forest, 115 E. 900 N., Richfield, UT 8470l. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Site Selection -------------------------------

Historical Cover Types 

Ecological restoration of pinyon-juniper landscapes requires a basic understanding of plant associations, distributions, and areas of occupation. It is important to recognize 

cover types that existed throughout the landscape prior to 

European settlement. It is also essential to know if landscapes currently supporting pinyon or juniper or both previously sustained mature and old pinyon or juniper, or ifareas 

were dominated by grasses, forbs, and shrubs. 

Two steps are basic to all considerations for ecological 

restoration including site selection, potential treatments, 

and species composition. First, recognize what the historical 

cover type for the area was 200 to 400 years ago. This 

historical cover type generally is assumed to be the plant 

association that is ecologically adapted for the area. Second, 

land managers, with information from stakeholders, should 

decide what cover type is desired for the area in the future. 

:Mature and Old Pinyon and Juniper-Many closed 

stands of pinyon and juniper were open or savanna-like 

communities with grasses and forbs flourishing in the 

interspaces. With altered ecosystem processes (such as heavy 

grazing and altered fire return intervals), Jacobs and 

Gatewood note that these areas have degraded as young 

trees filled the interspaces and displaced understory species. These authors explained that degraded "communities 

appear to have little capacity to recover .... Exclusion of 

grazing alone is insufficient to promote recovery of these 

systems." In many cases lack of ground cover results in 

erosion, soil loss, and removal of seed banks for the native 

understory species. 

Young Pinyon and Juniper-Many of these areas were 

also historically grass/forb cover types with scattered shrubs 

(Goodloe). Periodic fires precl uded the s urvi val of few, if any, 

pinyon or juniper trees, and seed sources for these trees were 

less abundant. 

Objectives and Guidelines 

Past rehabilitation efforts in pinyon and juniper types 

often have been conducted to improve livestock and big 

game forage and to provide cover and soil stability (McArthur 

and Young). 

271 
Soil and Watershed Protection-Planted species respond differently depending on growing conditions including soil, climate, and topographic features; thus, soil 

standards should reflect the capabilities to support different 

plant associations (Goodrich and Huber). Davis, Farmer, 

and Vernon concluded that chaining methods and the presence of litter left in place to protect soils also benefit establishment of seeded species. Goodrich and Reid compared the 

ground cover on burned and seeded and unburned pinyonjuniper sites in northeastern Utah. After 7 years, treated 

sites had 15 percent less bare soil and rock pavement and 

24 percent greater cover from litter and vegetation. 

Ground cover is a major factor preventing soil loss and 

sustaining good water quality. Farmer, Harper, and Davis 

found protective ground cover significantly reduced runoff 

and soil erosion from treated pinyon-juniper sites. They 

reported that "untreated control plots produced an average 

of nearly six times more runoff and nine times more sediment than chained plots." Considerable diversity in pinyonjuniper landscapes exist, and different responses to similar 

treatments are common. Lopes, Ffolliot, and Baker reported 

that "suspended sediment concentrations, above a threshold 

discharge, increased as a result of the cabling treatment, 

while no change in sediment concentrations was observed as 

a result of the herbicide treatment." Monsen and Pellant 

reported that "chaining did not reduce the percent of sites 

with hydrophobic conditions on or near the soil surface, but 

did reduce the number of sites having hydrophobic zones or 

layers at depths below 2.5 cm." Although infiltration conditions were not improved by tillage of the soil surface from 

chaining, the practice did significantly improve seedling 

establishment and plant cover. A more diverse assembly of 

species established as a result of creating better seedbed 

conditions. Presence of annual weeds was reduced by chaining and seeding over sites that were seeded but not chained. 

Chaining obviously improved seedbed conditions, resulting 

in improved ground cover during the first 2 years after 

treatment. 

Improve Wildlife Habitat-Fairchild explained that 

forage production for livestock was emphasized in some 

chaining projects on public lands during the 1950's and 

1960's. However, by the 1970's most project objectives included wildlife habitat restoration with a focus on improved 

big game winter range. He shared the basic premise that 

increased availability of foraging areas within larger 

pinyon-juniper woodlands, which provide thermal cover 

that is critical to animal survival, would reduce the home 

range of elk and deer on key winter ranges. Studies indicated 

that no more than 40 percent of home range for mule deer 

winter range (for areas of 125+ acres) should be chained at 

one time. Also, leave areas of 40+ acres should be distributed 

on a variety of slopes and aspects. 

Restore Native Species and Ecosystem ProcessesMcArthur and Young explained that, in the past, site adaptability and resource values were the most important criteria 

used to determine the particular species planted. Currently 

many other factors are considered. Stevens stated, "Converting juniper-pinyon communities to only an assembly of 

foreign species is not advisable." Desired objectives of the 

project will determine what species are planted (Britton, 

Anderson, Horrocks, and Horton). 

272 

Bates, Miller, and Svejcar explained that in eastern 

Oregon, understory diversity and productivity were restored when competing western juniper were cut. They 

stated "that, priortojunipercutting, a qualitative prediction 

of early succession species assemblages and dominance 

patterns can be made based on a site's initial floristics." 

Walker discussed the competitive and aggressive nature 

of many exotics, which "are often detrimental and have an 

adverse impact on natural functioning plant communities 

and ecosystems." During the conference, Monsen implored 

the participants to place less emphasis on watershed restoration, wildlife habitats, or cattle forage. Rather, he suggested focus on restoring functional plant communities, and 

re-establishment of diverse plant associations. 

Rodent Control-Monsen indicated that rodent control 

measures are critical, maybe as important as any factor for 

the protection of treated areas and the establishment of new 

seedlings. 

Treatments ---------------------------------

Chaining 

Stevens described the types of anchor chains commonly 

used for chaining treatments: (1) smooth chains with the 

links unmodified, (2) Ely chain with lengths of steel bar or 

railroad rail welded crossways, and (3) Dixie sager with a 

rail welded horizontal to each link. He explained chains may 

be from 90 to 350 feet long and individual links may weigh 

40 to 160 pounds. Two crawler tractors are required to pull 

a chain, complete with swivels on the ends and often in the 

middle. Depending on the position of and distance between 

tractors, chaining patterns may be J-shaped, U-shaped or 

half-circle patterns. Different chains and treatment patterns result in varying degrees of percent kill to trees and 

shrubs as well as differential soil scarification and seedbed 

prep~ration. Stevens listed many advantages for leaving 

downed trees in place. 

Stevens expanded on the desirable characteristics of chaining, describing it as a successful way to restore areas with 

pinyon and juniper. Studies show chaining to be less destructive to vegetation and soil than plowing, disking, fire 

use, or herbicides. Appropriate chaining releases, rather 

than destroys, understory species and does not harm native 

seed banks. Studies by Monsen and Pellant confirmed that 

chaining did not disrupt or reduce recovery of native grasses 

and broadleaf herbs. Stevens stressed that chaining treatments, including time of use, offers more flexibility than any 

other treatment with minimum impact to resource values. 

Seeding, often done aerially with fixed-wing aircraft or 

helicopters, may occur before or during treatments such that 

the final pass of the chain covers the seed with soil. At the 

conference Monsen emphasized, "creating suitable seedbeds 

for all species planted is an important aspect of restoration, 

yet, of all of the things we fail to do, this is key." 

Davis, Vernon, and Farmer reported the use of a lightweight chain in treating a mature stand of pinyon-juniper 

with cliffrose interspersed in the understory. The treatment 

resulted in a dramatic recovery of cliffrose as plants were 

released from tree competition. The treatment minimized 

the impact to mature cliffrose plants, but still provided a 

USDA Forest Service Proceedings RMRS-P-9. 1999 
92 percent elimination of the pinyon and juniper trees. 

Monsen and Pellant evaluated chainings in eight paired 

watersheds following the Boise Foothills fire of 1992. The 

treatment did not hamper recovery of perennial forbs or 

grasses. The treatment significantly increased establishment of all seeded species including those with both small 

and large seeds. Beck, Stevens, and Walker reported the 

dynamics of herbaceous understory species over 31 years 

following anchor chaining of five pinyon-juniper woodlands 

sites in south-central Utah. The areas included no use and 

use by mule deer, lagomorphs, and livestock. During the 

first 5 years following treatment, annual plants increased in 

numbers and density. However, perennial species increased 

while annuals decreased after the initial 5 years. 

Beyond the specifics of various types of chaining treatments, many feel that these treatments hold promise for the 

restoration of native communities. -Chaining may be the 

treatment of choice for landscapes with mature or old pinyon 

and juniper (Monsen). Stevens recognized that native communities can be restored by chaining as endemic species are 

allowed to recover after tree competition is reduced. In 

addition, planting select native species may be required to 

supplement reestablishment of species that have been 

eliminated. 

Fire Use 

Prescribed fire is usually more economical and ecologically compatible for areas with younger pinyon and juniper 

and for treatment of mature and older trees located on steep 

slopes and less accessible sites. Erskine and Goodrich indicate that, following prescribed burning, areas of younger 

pinyon and juniper respond well with respect to improvement of ground cover, minimal soil erosion, and recovery of 

native species that dominate post-treatment seral communities. Costs for prescribed fire (more than 1,000 acres), 

seed, and aerial seed application were about $20 per acre 

(1989 dollars). Costs go down as treated areas enlarge. 

Favorable conditions for prescribed fire include high temperatures, low humidity, and clear skies. Where prescribed 

fire is used to treat steeper slopes, drainage bottoms are 

excellent ignition sources to create desired crown fires. 

Helitorches were the ignition source for all of the fires 

discussed in their paper. 

Fire is an economically feasible tool to enhance or change 

plant succession to grass-forb dominated communities created by initial chaining projects (Fairchild). However, chained 

areas that are 20 to 30 years old often provide excellent big 

game habitat, and burning these areas can significantly 

reduce fire-intolerant shrubs. Habitat could be impaired by 

burning at this time, so delaying burning for two to three 

decades may be advisable. 

Chemical Control 

Cheatgrass, an annual, often thrives on pinyon-juniper 

rangelands following burning or mechanical treatments, 

and thus competes vigorously with native perennials. Pellant, 

Kaltenecker, and Jirik reported the use ofOUS'J'® herbicide 

to control cheatgrass on rangelands in southwestern Idaho 

and northern Nevada. OUS'J'® is water-dispersable and 

USDA Forest Service Proceedings RMRS-P-9. 1999 

functions as a pre- and post-emergent herbicide. OUS~ 

may be applied either from the ground or aerially for $25 to 

$28 per acre. Both methods have provided control of cheatgrass for up to 2 years. Data indicate this means of control 

was more effective than disking or burning. The authors 

found remnant perennial grasses regained dominance and 

were more vigorous in the areas treated with the herbicide 

than nontreated sites. 

Other chemicals, such as Spike, have been used with 

mixed results to control or directly kill pinyon and juniper. 

None of the papers in this session dealt with any of these 

chemicals. 

Rollerchopping 

Large expanses of pinyon-juniper woodlands treated in 

past decades, often with a combination of chaining and 

seeding, are prime for a maintenance treatment. However, 

fire may not always be appropriate. Rollerchopping is relatively inexpensive and effectively restores site productivity 

(Sorensen). The treatment can be done any time or season 

the area is accessible and the soil is not sufficiently wet to be 

damaged by mechanical action. 

Sorensen explained that rollerchopping can be used to 

control sagebrush, juniper, and pinyon. During the treatment, brittle, woody plants are crushed and chopped in 

place. The treatment does not concentrate piles of slash that 

may need to be dispersed later. The action removes woody 

competition of nonsprouting species allowing remaining 

vegetation to increase. Some areas need not be rested prior 

to treatment. Other design advantages include the ability to 

leave groups, strips, or individual trees and also to provide 

irregular patterns that are visually pleasing and may improve wildlife habitat. Treatment costs usually vary from 

$25 to $30 per acre. 

Harvests 

Fuelwood Cutting-Loftin described a simulated 

fuelwood cut in a pinyon-juniper woodland on the Santa Fe 

National Forest. All pinyon less than 8 inches diameter and 

all junipers were removed during the treatment. The purpose of the treatment was to increase the number of herb aceous plants, stabilize soils, and increase water availability. 

Trees were hand-cut, limbed, and lopped. Within 2 years, 

herbaceous plant cover increased to nearly 2.5 times more 

than the control. This method may not be as efficient as 

treating with heavy equipment; however, the treatment is 

less destructive and is well suited for sensitive areas. This 

treatment reduced both soil erosion and establishment of 

invasi ve weeds. Fire will be re-introd uced to the treated area 

to control stump sprouts and abundant new pinyon and 

juniper seedlings and return the functional processes ofthis 

productive grassland ecosystem. This treatment was for 

both thinning and providing fuelwood. 

Thinning and Slashing-J acobs and Gatewood reported 

the results of a slash mulching and overs tory reduction 

project in north-central New Mexico that yielded two- to 

seven-fold increases in total herbaceous cover. However, 

additional soil surface preparation and seeding treatments 

did not improve the benefits over the initial treatment. 

273 
The character of the pinyon-juniper savanna was restored 

when mature trees were spaced about 15 to 20 meters apart. 

They "suggest that tree overstory removal reduces competition for limited water and nutrient resources while the 

scattered slash provides benefits to exposed soils: reducing 

runoff and sediment transport, increasing infiltration and 

soil moisture, moderating soil temperature, freeze-thaw and 

evaporation, redistributing nutrients, and mitigating grazing impacts." 

Thinning and slashing can also be used to treat historic 

grasslands where tree encroachment may occur. Managers 

can determine the shape and size of the treated areas, and 

selectively decide which trees to cut and which to leave 

(Barber and Chapman). These authors indicated that a more 

natural appearance occurs with better big game movement 

when groups of trees are left standing. Selective cutting can 

be effective but expensive (Davis). In another study, costs 

per acre for thinning were much higher than for chaining 

(Chadwick, Nelson, Nunn, and Tatman), and the authors 

concl uded that "thinning did not create an effective seed bed 

or provide for adequate seed burial. Mechanical means 

should be employed to create a seed bed and cover the seed, 

introducing additional costs to the treatment." 

Species Composition and 

Selection 

Most of the information in this section applies to plant 

species. However, an underlying assumption is implied: 

diverse communities of native flora provide habitat for 

diverse communities of native fauna. 

Young stated, "Decisions as to what plant materials to use 

in a given revegetation project are made on many levels, 

with economic considerations often competing with those of 

ecology. The decision nearly always boils down to what is the 

revegetation objective for this site." The Bridger Plant Materials Center, affiliated with USDA-NRCS, focused projects 

on the selection and establishment of native species to 

revegetate a wide array of difficult restoration situations 

(Majerus, Winslow, and Scianna). 

When harsh environmental conditions complicate reclamation of arid and semi-arid rangelands, efforts often fail to 

meet the objectives (Britton, Anderson, Horrocks, and 

Horton). These authors evaluated the performance ofa large 

group of species at two sites, sagebrush/grass and greasewood, and suggested further studies to determine which mix 

of species grow best together. 

Native and Introduced Species 

Stevens discussed how to create stable communities. Restoration efforts should include seeding with native species if 

the site does not have sufficient understory to exclude exotic 

weeds that would dominate the area otherwise. Walker 

indicated that competition from seeded introduced species 

affected differences in species composition for up to four 

decades (the length of the studies). This significantly reduced the frequency and cover ofthe desired native species. 

He shared four case studies from various cover types: gambel 

oak, aspen-mountain brush,juniper-pinyon woodlands, and 

274 

Great Plains grassland ecosystems. Smooth brome, intermediate w hea tgrass, and crested w hea tgrasses were some of 

the exotic species in the examples. In all cases, a shift in 

species composition occurred where exotic species were 

favored at the expense of native communities. Walker underscored that resource values declined with this loss of species 

diversity. 

McArthur and Young reported on seed sales and marketing information from two surveys. The first survey presented detailed data on seed production and sales of 47 

species from the Intermountain and Pacific Northwest regions. The potential to use these species greatly exceeds 

current use and the vol ume of seed that is or can be harvested from wildland stands. To meet the demand for many 

species, field-grown seed will be needed. The second survey 

contained information provided by five seed companies in 

Utah that sold seed of native species in 1996. These companies reported marketing significant amounts of native seed 

of 29 grasses, 39 forbs, and 42 shrubs. 

McArthur and Young indicated that recently increased 

enthusiasm to reconstruct natural plant communities by 

using regionally adapted native plants has resulted in more 

native plant materials becoming available from private 

suppliers. However, seeds of wheat grasses (and their relatives) and legumes (rangeland alfalfas and clovers) continue 

to be the most available and are the plants of choice for most 

rehabilitation projects in pinyon-juniper areas (McArthur 

and Young). Jensen and Asay reported that "breeding programs are progressing to develop improved grasses and 

legumes for resource conservation as well as for grazing and 

habitat for livestock and wildlife .... Improved forage yield, 

forage quality, and resistance to insects and diseases are 

receiving major attention. Added emphasis is being placed 

on persistence of perennial ryegrass and development of 

endophyte-free cultivars of tall fescue." 

Seed Mixes and Stockpiling 

McArthur and Young recognized that stockpiling seed of 

native species by principal users will assure that seed will be 

available when needed. Consistent production from private 

industry should result from the orderly stockpiling of native 

seed in public sector (such as Forest Service) warehouses. 

The authors described two successful stockpiling programs 

by public agencies: the Utah Division of Wildlife Resources 

Seed Warehouse in Ephraim, Utah, and the Bureau of Land 

Management Seed Warehouse in Boise, Idaho. 

Weed Control 

Goodrich and Huber stated, "features of pinyon-juniper 

communities strongly point to the need to develop a wide array 

of plant materials with the potential to compete with cheatgrass on a variety of exposures and many geological substra tes 

and soil types." Monsen explained that weeds are a major 

concern to most wildland communities, and pinyon-juniper 

woodlands are prone to invasion of annuals. Cheatgrass and 

other annuals have been a problem for decades, but squarrose 

knapweed, skeletonweed, and other perennials are rapidly 

expanding, and a new generation of perennial weeds appears 

adapted to extensive rangeland communities (Monsen). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Seed Certification 

If req uirements and standards of the Association of Official Seed Certifying Agencies are followed, seed quality 

(purity, germination, and presence of foreign material) as 

well as genetic identity and purity can be assured (McArthur 

and Young). "The certification system is applicable to seed 

and other propagating materials both wild collected and 

grown in production fields, whether natural or genetically 

manipulated populations" (Young). The seed industry and 

government agencies are expending efforts to improve seed 

testing, selecting native species, training collectors and 

growers, and providing standards for seed cleaning and 

storage. 

Field Tour and Chaining 

Demonstration ----------------------------

A weed may be defined as a plant out of place. During the 

pinyon-juniper chaining demonstration of the field tour for 

this conference, that definition flashed through my mind. 

Indeed, grasses and forbs along with some scattered brush 

species dominated much of this area that is seral to pinyon 

or juniper during at least the past five centuries. Historically, fire occurred in the areas we visited with sufficient 

frequency to preclude survival of pinyon and juniper seedlings and, thus, perpetuated grass and forb cover types. In 

these areas, pinyon andjuniper on the landscape are similar 

to pigweed in a garden plot. Chaining overgrown stands of 

pinyon and j uni per is similar to a gardener pulling or hoeing 

out abundant "pigweed" on a vast landscape. The result is 

the removal of competition and recovery of desired communities of native and/or introduced species. 

Discussion __________ __ 

New Information 

Notable strides made during the past decade demonstrate 

that restoration is possible for many landscapes. More 

information, seed sources, and native plant materials are 

available for restoration of pinyon-juniper areas than for 

any other vegetative type (Monsen). As the demand and 

supply increase, the cost of using native material in restoration projects should continue to decrease. 

There is a need to increase the amount offield-grown seed 

of native plant species (McArthur and Young). Walker showed 

that well-meaning introductions of exotic species adversely 

impacted the natural functioning of plant communities and 

ecosystems. His caution underscores the need for studies 

about the compatibility of exotics in natural systems. 

Management Implications 

Potential Conflicts-The potential for conflicting objectives exists with management of pinyon-juniper communities. Efforts to restore closed stands of pinyon-juniper by 

prescribed burning or chaining large areas (Monsen) and at 

the same time maintain sufficient "leave areas" are key to 

USDA Forest Service Proceedings RMRS-P-9. 1999 

improvement and management of big game winter range 

(Fairchild). Collaborative stewardship and accurate identification of key big game winter ranges are needed to reduce 

potential conflicts. 

The advent of OUS'f® as an herbicidal control of cheatgrass 

shows considerable promise. However, public perceptions 

about herbicides in general and effects on wildlife can limit 

herbicide use on public lands (Pellant, Kaltenecker, and 

Jirik). IfOUS'f® is deemed suitable for large-scale application, an opportunity exists to treat areas with mixed stands 

of native species and selectively remove undesirable species. 

There will be a need to share information with the public 

about the benefits and relative risks ofthis herbicide before 

widespread acceptance will be found. 

Partnerships-Joint ventures among State and Federal 

agencies and private landowners will be important for future management of pinyon-juniper woodlands (Fairchild). 

For example, he suggested that range managers could redesign old chainings by thinning or clear-cutting to increase 

the area of usable mule deer habitat. Davis underscored the 

critical importance of the age structure of the stand to be 

treated. 

Prioritize Potential Treatment Areas 

Land managers with the responsibility to discern areas to 

be treated should recognize at least four landscape situations (Monsen): 

1. Restoration may be accomplished relatively quickly 

with some changes in management practices (such as altering grazing systems, burning, chaining, etc.). 

2. Restoration is feasible but will require supplemental 

seeding with native species. 

3. Restoration may be possible for some areas, but substantial alteration ofthe site and existing weed communities 

before restoration begins. 

4. Restoration is not possible but areas may still be rehabilitated. 

Monsen concluded that when designing restoration 

projects, diverse areas should be identified. These include 

areas separated by soil type, terrain, slope, aspect, and 

presence of herbs, shrubs, and trees. Land managers and 

researchers should work closely to develop a systematic way 

to delineate these site conditions. Managers could then 

categorize the pinyon-juniper areas into one of the four 

landscape situations. Only after sites have been properly 

classified, can managers determine which actions are required to restore an ecological balance. Care should be given 

not to prioritize all restoration effort on the basis of total 

acres restored for the dollars spent. Such priorities could in 

effect preclude treatments in critical pinyon-juniper sites 

where watershed and ecological stability are necessary. 

Where restoration is possible, but some rehabilitation is 

needed initially, it is important to ensure that the first 

treatments (such as seeding with certain exotics) do not 

compromise or preclude later restoration measures. However, in some situations where restoration is not currently 

possible, the goal should be to promote ecologically sensitive 

rehabilitation using species that will not dominate the area 

275 
but rather occupy a niche in the newly derived community. 

Sadly, some areas may be too expensive to rehabilitate. 

The "Land Ethic and an Ecological 

Conscience" 

The title of this session is "Ecological Restoration." Thus, 

I interject some considerations from the ecological perspective with themes taken from the writings of AIdo Leopold. 

While visiting Germany in 1935, Leopold penned part of 

an essay on the back of hotel stationary. He wrote: "One of 

the anomalies of modern ecology is that it is the creation of 

two groups, each of which seems barely aware of the existence of the other. The one studies the human community, 

almost as if it were a separate entity, and calls its findings 

sociology, economics, and history. The other studies the 

plant and animal community, and comfortably relegates the 

hodge-podge of politics to the liberal arts. The inevitable 

fusion of these two lines ofthought will, perhaps, constitute 

the outstanding advance of the present century" (Bradley 

1997). The close parallel of the papers presented in the 

"Ecological Restoration" session and in the "Management 

Implications" session of this conference demonstrate that 

this "fusion of two lines of thought" is occuring in the 

management of pinyon-juniper landscapes. It will be the 

challenge and the hope of this generation of researchers and 

managers to cement this fusion on behalf of sustaining 

productive historical pinyon-juniper woodlands and recovering and restoring landscapes that were previously healthy 

grass/forb/shrub communities but invaded by pinyon or 

juniper in the past several decades. 

In "Oregon and Utah-Cheat Takes Over" Leopold (1949) 

wrote: "I listened carefully for clues whether the West has 

accepted cheat as a necessary evil, to be lived with until 

kingdom come, or whether it regards cheat as a challenge to 

rectify its past errors in land-use. I found the hopeless 

attitude almost universal. There is, as yet, no sense of pride 

in the husbandry of wild plants and animals, no sense of 

shame in the proprietorship of a sick landscape. We tilt 

windmills in behalf of conservation in convention halls and 

editorial offices but on the back forty we disclaim even 

owning a lance." 

Leopold's (1949) concept of the land ethic enlarged the 

community boundaries to consider soils, waters, plants, and 

animals collectively as the land. "A land ethic, then, reflects 

the existence of an ecological conscience, and this in turn 

reflects a conviction of individual responsibility for the 

health of the land. Health is the capacity of the land for 

self-renewal. Conservation is our effort to understand and 

preserve this capacity." An A-B cleavage exists in many 

disciplines or specialized fields. "In each field one group 

(A) regards the land as soil, and its function as 

commodity-production; another group (B) regards the land 

as a biota, and its function as something broader .... Group B 

feels the stirrings of an ecological conscience." 

For ecological restoration to occur, factors other than big 

budgets and strong financial backing are critical. Leopold's 

philosophy and concluding challenge at the end of his "Land 

Ethic" has direct application to the situations that occur 

today on pinyon-juniper dominated landscapes in the West. 

He wrote: 

276 

"The 'key-log' which must be moved to release the evolutionary process for an ethic is simply this: quit thinking about 

decent land-use as solely an economic problem. Examine 

each question in terms of what is ethically and esthetically 

right, as well as what is economically expedient. A thing is 

right when it tends to preserve the integrity, stability, and 

beauty of the biotic community. It is wrong when it tends 

otherwise. 

It of course goes without saying that economic feasibility 

limits the tether of what can or cannot be done for land. It 

always has and it always will. The fallacy the economic 

determinists have tied around our collective neck, and which 

we now need to cast off, is the belief that economics determines all land-use. This simply is not true. An innumerable 

host of actions and attitudes, comprising perhaps the bulk of 

all land relations, is determined by the land-users' tastes and 

predilections, rather than by his purse. The bulk of all land 

relations hinges on investments of time, forethought, skill, 

and faith rather than on investments of cash. As a land-user 

thinketh, so is he. 

... By and large, our present problem is one of attitudes and 

implements." (Leopold 1949) 

At the close of the "Ecological Restoration" session of the 

conference, Richard Stevens gave a stirring challenge to the 

group. "The biggest problem is attitude!" Many native species can recover. However, native species may need to be 

rested more than 2 years, and a project cannot be judged a 

failure in the first 3 years. If the objective is to promote 

natives, plan for it. "If you build it, they will come! Have this 

kind of an attitude with native species," Stevens said. 

These are challenging and demanding times with complex 

iss ues for those who manage landscapes of expansi ve pinyon 

and juniper. Leopold's guiding keywords to make investments of "time, forethought, skill, and faith" must be applied 

if we hope to improve existing situations in pinyon-juniper 

ecosystems. We must be proactive, albeit at times on a 

shoestring. We cannot and must not be complacent with our 

ecological conscience and model a "hopeless attitude." We 

must challenge the status quo in our larger circles of influence and convey to politicians and the public that, although 

the "landscape is sick,"withoutthoughtful and skilled attention, conditions can and will become much worse. 

Should we burn? chain? harvest? or do nothing? If treatments are made, then the questions become: how big? what 

shape? seed with natives? seed with exotic species? rely only 

on the seedbank? Such questions land managers will ask. 

Answers should depend on the desired conditions for the 

landscapes as determined by managers after weighing 

in put from informed stakeholders in a forum of collaborative 

stewardship. The full range of alternatives (including doing 

nothing) should be applied to the full range of sites and 

situations on these landscapes. Also, monitoring of conditions, treatments, and responses is essential to understand 

the effects of treatments and then to adapt future actions. 

Refer to the four compelling case studies in Walker to 

appreciate the value oflong-term monitoring. 

Land managers mustj udiciously weigh the prudent use of 

chaining and where feasible restore the ecosystem process of 

fire to its historical function. These are challenging times 

with the hope of an improved future. Steps must be taken to 

value native species in sustainable communities. Unless we 

use landscape-scale measures to control undesirable exotic 

species, the legacy of this generation to coming generations 

USDA Forest Service Proceedings RMRS-P-9. 1999 
will be populations of even less desirable exotic species on 

these landscapes. 

The challenge for researchers and land managers is to be 

proactive in restoring the ecological integrity of pinyon -juni per 

ecosystems. These landscapes have the potential to sustain 

healthy and diverse biological communities. Let this be our 

legacy to future generations. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

References _________ _ 

Bradley, Nina Leopold. 1997. Of the Land. American Forests. 

103(2)25-29. 

Leopold, Aldo. 1949. A Sand County Almanac and Sketches Here 

and There. New York, NY: Oxford University Press. 226 p. 

All other citations are to presentations at the symposium, most of 

which are included in these proceedings. All are in abstract form 

in "Brigham Young University, 1997. Ecology and mangement of 

pinyon-juniper communities within the Interior West." Brigham 

Young University, Provo, UT. Non-paginated. 

277 
Pinyon-Juniper Chaining Design Guidelines 

For Big Game Winter Range Enhancement 

Projects 

John A. Fairchild 

Abstract-There are numerous examples of pinyon-juniper chaining projects in the Intermountain Region. The design of each reflects 

the objectives of the project and the "state-of-the-art" at the time of 

the chaining. Projects carried out on public lands in the 1950's and 

1960's emphasized forage production for livestock. The early pinyon-juniper chainings were characterized by large treatments with 

borders closely tied to property boundaries. In the 1970's, the list of 

project objectives expanded to include wildlife habitat restoration, 

with an emphasis on enhancement of big game winter range. These 

projects were designed with irregular boundaries, "leave areas" 

and travel corridors to capitalize on the "edge effect" described by 

Aldo Leopold back in the 1930's. Consideration of mule deer habitat 

requirements and behavioral adaptations for winter survival is 

critical for planning projects on winter ranges. Guidelines are 

presented for treatment designs to protect and enhance wildlife 

habitat on these ranges. 

The Utah Division of Wildlife Resources has been involved 

in chaining projects on mule deer winter ranges for more 

than 40 years. The practice has been used to improve winter 

range habitat on numerous wildlife management areas 

throughout the state. Projects have been carried out on 

public land in cooperation with the U.S. Forest Service and 

the Bureau of Land Management. In addition, the Division 

has contributed browse and forb seed to landowners that 

have selected chaining as a method for increasing forage 

production on their private rangeland. In most cases, the 

landowners have developed a conservation plan for their 

property with the assistance of the Natural Resource Conservation Service. 

The basic premise has been that if we increase the availability offoraging areas within the larger woodland, then we 

should be able to red uce the home range of elk and mule deer 

on their winter range. If successful, animals should be able 

to conserve energy, and be better equipped to survive harsh 

winters. Treatment design, seeding success and long-term 

management will determine the ultimate value of these 

projects for wildlife. The following is a summary of the key 

habitat requirements and behaviors that must be considered when developing guidelines for a chaining design. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

John A. Fairchild is Habitat Manager, Utah Division of Wildlife Resources, 

Central Region, 1115 North Main St., Springville, Utah 84663. 

278 

Effect of Home Range ____ _ 

To understand the constraints that need to be imposed on 

chaining to achieve benefits for mule deer, it is important to 

keep in mind that the project will affect a species whose 

home range during the winter may be as small as 125 acres. 

Estimates vary depending on the area, but to conserve 

energy, it is not uncommon for deer to limit their activity to 

a %-mile activity radius. A treatment can be expected to 

have a positive effect on a local mule deer population if the 

project scale (chained vs. unchained area) is set based on 

this critical acreage. For example, a 200-acre chaining, 

without leave areas, could totally displace the animals that 

traditionally use a particular area and force them to move 

into an area occupied by another group. Long-term carrying 

capacity for the area could be reduced. 

ThermaICover ________________ _ 

For mule deer, energy conservation during the winter is 

the key to survival. Deer carry a portion of their winter 

range on their back in the form of fat. Regardless of range 

conditions, deer continue to lose weight during the winter. 

The rate of loss, which is affected by habitat conditions 

and the severity of the winter, determines survival The 

thermal cover provided by pinyon-juniper woodlands provides a buffer against exposure to severe weather conditions. The trees serve as a windbreak which reduces the 

wind-chill factor. Deer move to the interior of dense stands 

to avoid the strong winds associated with winter storms. 

To conserve energy at night, deer select areas beneath the 

tree canopy to bed down. The tree canopy absorbs heat 

during the day and reradiates the heat back to the ground at 

night, thereby increasing the air temperature beneath the 

canopy. 

Interspersion of Vegetative Cover 

Types 

Deer are attracted to areas where thermal cover and 

feeding areas are in close proximity. Again, energy conservation probably drives this behavior, but predator avoidance 

is also involved. Recognition of this "edge effect" has influenced the design of chaining projects over the last 20 years. 

First introduced as a concept by AIdo Leopold in the 1930's, 

it took a while to get incorporated into land management 

practices. Since treatment designs are often driven by watershed and forage production objectives, wildlife habitat 

remains an issue that must be negotiated for most projects. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Mule Deer Distribution on Winter 

Ranges ______________________ _ 

It is important to keep in mind that mule deer are not 

evenly distributed on their winter range. When planning a 

chaining project, we need to distinguish between normal and 

critical use areas. The nutritional status of mule deer changes 

as they are forced by severe weather to occupy lower elevation pinyon-juniper stands. If there is insufficient thermal 

cover available on these critical winter ranges, then the 

herd will be subjected to additional stress. 

Deer tend to concentrate in what are called "key areas." 

Due to a combination of elevation, slope, aspect, topography, 

thermal cover and the presence of sites that support preferred browse species, deer are not distributed uniformly 

throughout their range. Chaining design is especially critical in these key areas, if they are to be chained at all. 

Chaining Design Guidelines 

Thermal Cover 

The chaining design should reflect the importance of 

thermal cover over the need for foraging areas. Studies 

have suggested that no more than 40 percent of a pinyonjuniper stand should be chained within the expected home 

range of wintering mule deer (Thomas and others 1979). If 

the conservative estimate of a 1/4 mile radius is used as an 

estimate for home range during the winter, then no more 

than 50 acres should be chained in a 125 acre area. An upper 

limit of about 260 acres per section would be possible, 

depending on terrain. 

Interspersion 

To maximize interspersion of cover types, and increase 

utilization by deer, the distance from any chained location to 

the edge of an untreated stand (leave area) should be no 

greater than Ys mile (660 feet). Terrel (1973) found that deer 

use in a chained area was greatest near the edge and 

dropped off significantly 400 feet in either direction. Consequently, chaining widths should be no greater than 1/4 mile. 

Leave areas should be at least 40 acres in size and be distributed on a variety of sites (different slopes and aspects). 

Leave Areas 

The oldest stands should be incorporated into the leave 

areas. These stands provide considerable amount of concealment and thermal cover for mule deer. They generally 

occupy the shallowest soils, with less potential for forage 

prod uction. 

Scattered Trees 

Clumps of trees should be left scattered throughout the 

chaining. These clumps are not considered leave areas, but 

provide hiding cover and habitat diversity within the chaining. These sites provide perching areas for raptors, and 

facilitate movement through the area by other bird species. 

The spacing for the clumps should be at least every 300 feet. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Travel Corridors 

Travel corridors (ridges and drainage bottoms) should be 

excluded from treatment. The corridors should be at least 

300 feet wide. Leave areas should be arranged so that they 

are connected by travel corridors. 

Site Selection 

Chainings should be located on soil types that have the 

potential to produce a diverse stand of vegetation. The best 

sites for browse production should be included in the chaining (Plummer and others, 1968). 

Vegetation Management ____ _ 

The reestablishment of Utah Juniper and Pinyon Pine 

on previously chained areas has been well documented 

(Van Pelt and others 1990, Stevens 1987). Most ofthe trees, 

in these treated areas, were young plants at the time of 

the chaining and were not affected by the treatment. Shrubs, 

including highly nutritious browse species, can become the 

predominant species in the understory. Gradually, as tree 

and shrub densities increase, herbaceous production decreases. When one of the management objectives is to provide livestock forage, as is the case on most Western rangelands, pinyon-juniper maintenance treatments are often 

considered to restore maximum productivity. 

Fire can be an effective, low-cost tool to arrest plant 

succession and reestablish a grass-forb dominated community in the openings created by the initial project. Although 

a prescribed burn may have a positive effect on forage 

production for livestock, the loss of browse production on a 

critical big game winter range could have serious consequences for the local deer herd. Key browse species are often 

just beginning to contribute significantly to the diet of the 

wintering deer herd when a maintenance treatment is 

carried out. After 20-30 years, these chained areas often 

have higher habitat value for big game, based on cover and 

forage characteristics, than during the early post-chaining 

period. Consideration should be given to the importance of 

an area for wintering big game when evaluating the need for 

maintenance. 

Conclusions ------------------------------

Pinyon-juniper woodlands provide key winter use areas 

for mule deer and elk throughout Utah. The thermal cover 

provided by this ecosystem has an important function in 

energy conservation by big game. Consequently, the habitat 

value of a chaining is more closely tied to the proportion of 

the woodland that is left untreated, and its interspersion 

with treated areas, than to the amount of acreage that is 

converted to herbaceous cover. 

Range managers have an opportunity to redesign old 

chainings to increase the acreage of usable habitat by mule 

deer. Many of these early projects failed to take into 

consideration the thermal cover requirements of big game. 

Ifprescribed burning is selected as the tool to retreat key use 

areas, careful consideration will have to be given to the postburn design to maintain wildlife benefits. Another option 

279 
that is available to land managers in Utah is to contract 

with the Utah State Division of Forestry, Fire and State 

Lands, Lone Peak Conservation Center, to clearcut or thin 

previously chained areas. The Lone Peak Conservation 

Center, in cooperation with the Utah State Department of 

Corrections, employs a prison work force to carry out a 

variety of conservation practices. 

Joint ventures involving federal land management agencies, private landowners, state agencies, and Soil Conservation Districts, will playa bigger role in the management 

of pinyon-juniper woodlands in the future. The high cost of 

rangeland conversion projects dictates the need for partnerships. It is very important that wildlife habitat protection 

and enhancement be among the objectives identified for 

these projects. 

280 

References ---------------------------------- Plummer, A. P.; Christensen, D. R; Monsen, S. B. 1968. Restoring 

big game range in Utah. Utah Div. Fish and Game, Pub!. 68-3, 

183 p. Publishers Press, Salt Lake City. 

Stevens, R 1987. Thirty years of pinyon-juniper big game habitat 

improvement projects: what have we learned. In: Everett, R L., 

compo Proceedings: pinyon-juniper conference; 1986 Jan. 13-16; 

Reno, NV. Gen. Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research 

Station: 558-571. 

Terrel, T. L. 1973. Mule deer use patterns as related to pinyonjuniper conversion in Utah. Ph.D. thesis. Utah State Univ., 

Logan. 174 p. 

Thomas, J. W.; Black, H. J r; Scherzinger, R J.; Pedersen, R J. 1979. 

Deer and Elk. In: Thomas, J. W., Tech. Ed. Wildlife habitats in 

managed forests: the Blue Mountains of Oregon and Washington. 

Agric. Handb. No. 553: U.S. Department of Agriculture, Forest 

Service. 104-127. 

VanPelt, N. S.; Stevens, R; West, N. E. 1990. Survival and growth 

of immature Juniperus osteosperma and Pinus edulis following 

woodland chaining in central Utah. The Southwestern Naturalist 35(3): 322-328. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Mechanical Chaining and Seeding 

Richard Stevens 

Abstract-Density of pinyon and juniper trees and shrubs can be 

effectively reduced, large shrubs can be pruned, seedbeds can be 

created, and seed covered with an anchor chain pulled between two 

crawler tractors. Positioning of the tractor, chain size, and modification to the chain can produce a multitude of results. Seeding is 

most often done aerially using fixed-wing and helicopter aircraft. 

Chaining __________ _ 

Anchor chains are primarily used to uproot trees and 

shrubs, to create seedbeds, to top or prune large shrubs, and 

to cover seed. Anchor chains from large destroyer or cruiser 

ships, 40- to 160-lb per link and 90 to 350 ft long are 

employed. To be effective, swivels are required at both ends 

and are recommended additionally, at least in the middle of 

the chain. 

Anchor chains are pulled behind two crawler tractors 

traveling parallel to each other. To be effective, chains 

should not be stretched taut, but must be dragged in a 

loose, J-shaped, U-shaped, or half circle pattern. The halfcircle configuration provides the greatest swath width, lowest percentage kill, and should only be used in mature, evenage tree stands. Kill and disturbance increases as the width 

ofthe J- or U-shaped pattern decreases. As the proportion of 

trees and shrubs change, chaining width should decrease or 

increase in order to achieve the desired amount of kill. The 

heavier the link, the better the chain stays on the ground, 

and the higher the percentage kill (Stevens and Monsen, 

In press). 

Chaining commonly occurs. on slopes of up to 50 percent 

slope but has been successfully accomplished on 65 percent 

slope (Vallentine 1989; Stevens and Monsen, In press). 

Chaining can occur up and down or across the slope without 

adversely affecting watershed values. 

Success in removing trees and shrubs varies with species 

composition, age structure, density, and rooting habit. Trees 

in mature, even-age stands can be killed more effectively 

and efficiently than in uneven-age stands. Young trees less 

than 48 inches tall may not be killed with single or double 

chaining because the chain may ride over them. Small 

junipers can be uprooted and killed more effectively than 

small pinyons that tend to be more flexible than junipers. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Richard Stevens was Project Leader/Research Biologist (retired), Division 

of Wildlife Resources, Great Basin Experiment Station, Ephraim, UT 84627. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Three basic types of chains are used in pinyon-juniper 

projects: 

1. Smooth Chain-Unmodified smooth links of various 

lengths and weights. Swivels are required on both ends. 

2. Ely Chain-Anchor chains with steel bars, hard surfaced railroad rail, are I -beam welded crossways to every 

link, every other link, or every third link. Bar length will 

vary with link size but should extend 4 to 6 inches beyond 

both sides of the link. The 10 to 15 lead links at either end 

of the chain are left smooth. Swivels are required at both 

ends and in the middle of the chain. 

3. Dixie Sager-An anchor chain with railroad rail welded 

to each side of each link, horizontal to the link. Length of rail 

depends on link length. The rail should be approximately 

one-half the total length of the link. Rails are welded with 

the crown of the rail next to the link, and base of rail out. 

Lead chains on each end consist of 10 to 15 smooth links. 

Swivels are required at both ends and in the middle of the 

chain. 

With all three chain types, percent kill and amount of 

soil disturbance increases with link size. Compared to a 

smooth chain, Ely chains do a better job of scarifying soil 

and preparing a desirable seedbed. Tree and shrub kill is 

improved with an Ely chain over a smooth chain. The Ely 

chain does, however, have a tendency to hook and roll 

downed trees and shrubs to the center ofthe chain. The Dixie 

sager was designed to uproot big sagebrush. It does an 

excellent job of uprooting sagebrush and scattered pinyon 

and juniper. The Dixie chain will do a better job than a 

smooth chain of soil scarification, and of sagebrush, small 

juniper, and pinyon kill. The Dixie sager does not work well 

in pinyon-juniper stands since the railroad rails tend to hook 

trees and carry them along; this lifts the chain offthe ground 

and reduces soil scarification and the number of trees and 

shrubs killed. Smooth chains are preferred when the objective is to release and open up tree and shrub communities 

such as pinyon-juniper, big sagebrush, aspen, mahogany, 

serviceberry, Gambel oak, chokecherry, bitterbrush, cliffrose, 

winterfat, and shrubby eriogonum. When removing trees 

and most shrubs, twice-over chaining is necessary. The first 

chaining completely uproots some trees; however, many 

trees are not completely uprooted and are laid down in the 

direction of chaining with some roots still in the ground. The 

second chaining should occur in the opposite direction, this 

generally uproots and tips the downed trees over. Many 

shrubs that come in contact with the chain can be uprooted 

or broken off. Twice-over chaining increases percent kill 

and topping of shrubs. Seeding should occur between 

chainings, as the second chaining covers the seed. If single 

chaining occurs, seeding should take place prior to chaining. 

Once-over chaining may be adequate when sufficient understory remains, trees are mature, an objective is to only 

reduce tree density, and seeding is not planned. 

281 
", 

It is generally advantageous to leave downed trees in 

place and not pile or burn them. Some advantages to 

leaving trees in place include: (1) increased amount of 

infiltration by increased retention and detention of surface water; (2) increased ground cover; (3) decreased erosion; (4) cover maintained for wildlife; (5) big game and 

livestock movement onto and throughout the treated 

area is encouraged, resulting in more even distribution and 

use; (6) provide shade for livestock and big game; (7) decreased livestock trailing; (8) provides safe sites for seedlings to establish, seedling survival is improved, especially 

shrubs, and (9) cost of piling and burning is eliminated. 

Some advantages to removing trees are: (1) improved vehicular access; (2) enhanced access to all forage by grazing 

animals; (3) fewer rodents; (4) reduction in fire potential, 

and (5) esthetics (Stevens and Monsen In press). 

Desirable characteristics of chaining include: 

1. Chaining is an effective method for restoring 

juniper-pinyon communities. Chaining can be effectively 

used to regulate or manipulate a community without destruction of understory species. Chain link size, modifications to links, and placement of crawler tractor will determine disturbance severity to understory species. Types and 

size of chain and chaining practices can be regulated to 

retain most all existing understory species including threatened and endangered species, yet sufficiently reduce tree 

competition to facilitate seeding or promote natural recovery of understory species. Native seedbanks are not harmed 

by appropriate chaining. 

Through extensive testing and development of alternate 

equipment, chaining has proven to be the least destructive 

technique to existing vegetation and soil. Compared with 

other methods of mechanical treatment (plowing, disking), 

or use of herbicides or fire, this practice can be selectively 

used to reduce tree density in desired locations without 

disruption of understory plants and non target areas. 

Soil conditions, including watershed stability, can be 

improved with chaining (Farmer and others, this Proceedings). Many treatment practic~s, including burning, leaves 

bare soil and sites subjected to extensive erosion for considerable periods. Chaining can leave considerable litter on the 

surface, which improves watershed protection by retaining 

and detaining surface moisture and increasing the amount 

of infiltration (Roundy and Vernon, this Proceedings; Wood 

1988; Wood and Javed 1994; Wilcox 1994). Debris is also 

deposited in gullies, draws, and waterways, thereby improving retention and detention of surface moisture and decreasing amounts and duration of runoff and sedimentation. 

A primary advantage of chaining, to watershed and vegetative conditions, is the practice can be used at most any 

season of the year. Plowing, spraying, and burning must be 

conducted at very specific times, depending on soil moisture, 

stage of plant growth, and site access. Treatment by these 

methods is often completed at a time when sites are subjected to erosion or seedbed conditions are not the most 

desirable. In many situations, burning, cutting, hula dozing, 

or other methods of plant control require follow up seeding 

treatments to reduce soil erosion or limit weed invasion. 

Chaining allows treatment to be conducted at the most 

appropriate season to benefit soil stability, create a desirable seedbed, cover seed, and reduce the invasion of weeds. 

282 

Currently, no other treatment provides the flexibility afforded by chaining. 

Chaining and seeding can also be effectively used to help 

control understory weeds that normally exist within depleted juniper-pinyon status. Since chaining does not 

generally disrupt the existing perennial understory species, 

desirable perennials can recover quickly (Jacobs and 

Gatewood, this Proceedings) and provide immediate competition to potential weeds. Adding species by seeding can also 

increases competition with weedy plants. Soil nutrients and 

site productivity can be maintained by chaining. Surface 

litter and plant debris are maintained on site, whereas 

burning removes nutrients, litter and debris. Soil profiles 

are not disrupted with chaining as they would be with 

plowing or disking. 

2. Chaining can be an effective method for selectively removing a desired density and age class of 

trees. Chaining is a technique that can be used to maintain 

selected trees, if desired. The amount or number of trees 

removed can easily be regulated by widening or narrowing 

the operating distance between the crawler tractors, or 

changing speed or direction of operation. The weight or size 

of the chain used and the number and position of swivels 

located in the chain can also be used to regulate the extent 

of tree removal. Different types of equipment are not required to effectively treat highly variable site conditions. 

Prior to chaining, the area can be inventoried and a chain of 

appropriate size and length can be selected to treat most all 

circumstances. Once a chain size is selected, operational 

procedures can be developed to assure proper treatment is 

attained on all sites. Hula dozing or cutting of individual 

trees also provides considerable flexibility, but costs and 

treatment time are normally prohibitive and number of 

acres treated per day is low and most treated areas still have 

to be properly seeded. 

Chaining can be very site specific, and can easily be 

regulated to specific community types, aspects, or acreage. 

Compared with burning, this practice can be specifically 

targeted to desired sites including small, irregular tracts. 

The degree of tree removal using chemical sprays or burning 

is difficult to control. Areas treated with either of these 

practices normally result in complete removal of all vegetation, although stands or patches may be left that are untreated. However, it is much more difficult to remove only a 

certain fraction ofthe trees without also affecting the understory by burning or chemical spraying. 

Since chaining can be conducted during almost any season, the extent of trees or understory removed can somewhat 

be regulated by treatment dates and condition of the soil 

and vegetation. Chaining, during early winter, when plants 

are brittle and snow covers the understory, generally results 

in removal of trees and some shrubs, including big sagebrush, without damage to understory herbs. Chaining, during the growing season when woody species are more flexible, normally leaves more shrubs undamaged. Chaining 

late in the growing season, when soil moisture has been 

depleted, results in more complete uprooting of trees, than 

if sites are chained in early spring. 

Chains with attached swivels and couplings are available 

to most public agencies and private users. Transportation 

and set up costs can be quite variable. Individual chains 

require little maintenance and repairs are very infrequent. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Compared with other machinery, repair costs are minimal 

and little investment is needed for tools or items to support 

chaining. 

3. Chaining can provide adequate seedbeds for many 

species and is a technique that can be used to cover 

seed on diverse sites. Various practices used to control 

trees-spraying, burning, hula dozing, and hand cutting do 

not prepare a seedbed nor aid in actual seeding. Chaining 

can, however, prepare satisfactory seedbeds on steep, irregular, even and uneven terrain, and on critical watershed 

sites. Under normal chaining conditions, suitable seedbeds 

are created to plant seeds of a number of species, having 

different seedbed requirements. The chain creates numerous micro sites and allows for shallow or deep planting 

depths. In addition, seeds can be broadcast before or after 

chaining, to achieve the desired planting depth, surface 

compaction, and stand establishment. Planting before or 

after chaining will have an influence on which species may 

initially establish, and ultimately become prominent in the 

plant community. 

Natural seeding of a selected native species can be promoted when chaining is conducted following seed production. Chaining also promotes sprouting of some species, and 

if done at the correct season favors their recovery and 

spread. Chaining can also be scheduled to diminish or 

control the spread of weeds. Ifunderstory herbaceous weeds 

occur, chaining can be completed in the early summer prior 

to weed seed maturation. At this date, good control of the 

trees can be achieved without planting weed seeds. 

Chaining and seeding can be conducted at the most appropriate season favoring establishment ofthe planted species. 

Fall seedings over the majority of the Intermountain west 

has proven to be the most ideal time to seed. Where spring 

seedings are employed, they need to occur prior to midMarch. In southern Utah, southern Nevada, and northern 

Arizona, seeding just prior to the mid-July summer storms 

has resulted in good success. 

A uniform seedbed can be prepared with chaining even 

on rough, steep, and irregular sites. Few sites are left 

untreated with chaining where weeds may gain control. 

Attaining uniform and competitive stands on irregular terrain and variable soil conditions is extremely difficult with 

most conventional seeding practices. Chaining produces 

the most uniform stands on poorly accessible sites of any 

technique now available. 

Although burning or spraying can be used to control tree 

competition, an additional technique is needed to prepare a 

seedbed and to plant desirable seeds. Seeds may be broadcast on fresh burns or sprayed sites, however most all species 

require some degree of seed coverage. Seeds of many desirable species must be incorporated into the soil, others do 

best surface seeded on disturbed soil. Chaining provides all 

degrees of coverage, resulting in the establishment of a 

diversity of species. Chaining will favor soil moisture accumulation. The practice can be accomplished without seriously disturbing the soil and causing the surface to dry 

rapidly. Litter is retained on site to protect and enhance the 

seedbed. Chaining and seeding can be accomplished when 

sites are bare or covered with snow, without accelerating 

runoff and loss of moisture. Although some land managers 

fail to recognize the importance of having seed in the ground 

USDA Forest Service Proceedings RMRS-P-9. 1999 

at specified periods when soil moisture is most favorable 

this is one of the most critical issues determining plantin~ success. Chaining offers a seeding option to quickly and 

effectively treat small and large divers sites. 

Removing trees from steep mountain slopes with fire and 

spraying can create excessive runoff and soil erosion unless 

additional practices are used to stabilize the soil. In contrast, 

chaining will improve ground cover, retains and detains 

surface moisture, increases amount of infiltration, reducing 

runoff and providing a stable seedbed and watershed. With 

chaining, no additional treatments are required to assure 

site stability. 

4. Chaining can have minimum impact on resource 

values. Any plant conversion or regulation practice can 

im pact a number of wildland resources. Most revegeta tion or 

restoration measures should be designed to remove existing 

weedy species and reestablish natural plant succession. 

Removal of existing weedy trees creates an abrupt and 

often dramatic change in plant density, structure, and age 

class. Recovery of the native species can frequently take 

many years to provide a visible mature assembly of plants. 

During the recovery period the impacts can be quite apparent. When properly done, chaining will not degrade or 

destroy soil or watershed resources. It is a practice designed 

and modified to stabilize erosion and provide a desirable 

seedbed. The selection of an appropriate treatment practice 

should be based on the desirable impacts imposed on all 

resource values. Because of depleted understory and erosion, potential seeding of desirable adapted compatible species is most often required. 

Seeding 

The majority of juniper-pinyon chaining and fires in the 

Intermountain west have been aerially seeded. If double 

chaining is employed, seeding should occur before the final 

treatment. The final chaining normally provides good seed 

coverage. Seeding should occur prior to the chaining when 

one-way chaining is employed. Aerial broadcasting using a 

fixed-wing aircraft and helicopters is used to distribute seed 

on areas that have been chained. Planting success is usually 

dependent upon time of seeding, seedbed conditions and 

thoroughness of seed coverage. 

Aerial seeding can seed large acreages in an extremely 

short period. Large revegetation projects can often be more 

successfully seeded using aerial techniques and chaining 

than drill seedings, as planting can be completed during 

short planting periods or windows when seedbed and weather 

conditions are most favorable. Aerial seeding can be conducted when wet soil conditions hamper drilling. Drill seeding occurs at a much slower rate than does aerial seeding. 

Many times it is impossible to physically get over large 

acreages during various seeding periods with drills. This 

can result in considerable acreages being seeded out of 

season or totally omitted. With aerial broadcasting, seeding 

can be delayed until late fall or early winter, and then seeded 

in a relatively few days and covered with chains, rails, or 

cable scarifiers. 

Aerial seeding is also an effective method of seeding 

different seed mixtures on specific sites. Areas that support 

283 
distinct and different plant communities like riparian areas 

can be easily defined and planted separately from adjacent 

sites. 

Helicopter seeding is usually selected over fixed-wind 

aircraft if highly irregular shaped sites and variable terrains 

are seeded and when air strips are unavailable. Effective 

seeding of right-of-way, fence lines, steep slopes, small 

areas, rough rocky terrains, riparian drainage, and specific 

species placement can be accomplished with helicopters. 

Down draft and wind can cause seeds of different species 

to dissipate and fall separately, sometimes creating differences in stand composition and density. Variation in seeding 

and establishment is often advisable allowing for natural 

succession and spread of desirable species. 

Where downed trees and debris does not interfere, seed 

can also be covered successfully using drags or a pipe 

harrow. Single disk harrows, or similar light machinery, can 

also be used to cover seed in open debris, free areas. Care 

must be taken to ensure that seeds are not covered too 

deep and seedbeds are not too loose. 

Rangeland, or similar type drills can be used to seed many 

species on open areas. Again, care should be taken to 

ensure that seeds are properly covered. As a general rule, 

most seed should not be covered more than three times 

their own thickness, or to a depth of % to % inch. Some 

species do, however, require seeding on a disturbed soil 

surface. 

Seeds that are in short supply or those that should be 

seeded in a firm seedbed can be seeded with a Hansen seed 

dribbler or thimble seeder mounted on the deck of a crawler 

tractor. These two seeders allow seed to be metered out 

onto the crawler track, then embedded in the soil by the 

tractor's weight. 

La te fall un til mid win ter (October through Jan uary) is the 

preferred planting period. Seeding should not be attempted 

in frozen ground. Seedings should only occur when seed can 

be properly covered. Delaying seeding until late fall or 

284 

midwinter can reduce seed depredation by rodents and 

birds. Fall and winter plantings provides adequate time for 

stratification of planted seeds, and ensures that seed is in 

the ground when temperature and soil moisture conditions 

are most favorable (early spring) for germination and seedling establishment. 

Acknowledgments 

Funds were provided through Federal Aid in Wildlife 

Restoration Project W82R, Study 3 and Rocky Mountain 

Research Station, Forest Service, U.S. Department of Agriculture, Provo, Utah. 

References --------------------------------- Farmer, M. E.; Harper, K T.; Davis, J. N. 1998. These Proceedings. 

The influences of anchor- chaining on watershed health in a 

juniper-pinyon woodland in central Utah. 

Roundy, B. A.; Vernon, J. L. 1998. These Proceedings. Watershed values and conditions associated with pinyon-juniper 

communities. 

Stevens, R 1998. These Proceedings. Restoration of native communities by chaining and seeding. 

Stevens, R; Monsen, S. B. In Press. Pinyon juniper. In: Monsen, S. B.; 

Stevens, R, eds. Restoration and revegetation of west ern ranges 

and wildlands. U.S. Department of Agriculture, Forest Service, 

Gen. Tech. Rep. 

Vallentine, J. F. 1989. Range development and improvement, 3rd 

ed. San Diego, CA: Academic Press Inc. 524 p. 

Wilcox, B. P. 1994. Runoff and erosion in intercanopy zones of 

pinyon-juniper woodlands. Journal of Range Management 

47:285-295 

Wood, M. K 1988. Rangeland vegetation-hydrologic interactions. 

In: Tueller, P.T., ed. Vegetation science applications to rangeland 

analysis and management. Boston, MA: Kluwer Academic Publishers. 469-491 p. 

Wood, M. K; Javed, N. 1994. Hydrologic responses to fuelwood 

harvest and slash disposal in a pinyon pine and juniper dominated grassland. Trends in Hydrology 1:179-190. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Restoration of Native Communities by 

Chaining and Seeding 

Richard Stevens 

Abstract-With the use of proper equipment, techniques, seeding, 

and management, native communities can be restored. Reduction in 

competitive weedy tree density is essential in community restoration. Where sufficient understory exists, seeding may not be necessary. In most areas some degree of seeding is required. Species 

should be seeded that are adapted to site conditions, are ecologically 

adapted and are compatible with on .site endemic and seeded 

species. Consideration has to be given to seedbed and seeding 

requirements of each seeded species. Native communities can be 

restored when endemic species are given every opportunity to 

express them self and when native seeded species are provided 

maximum opportunity to germinate, establish, and become an 

active component of the community. 

Juniper-Pinyon communities have been in a consistent 

state offlux for the past 100 years. From the late 1800's to 

the present, distribution and density of pinyon and juniper 

and accompanying native understory has been significantly 

altered. A majority of the juniper-pinyon stands in the Great 

Basin prior to settlement were confined to selected areas, 

and supported a diverse understory of perennial grasses, 

forbs, and shrubs. Fire, combined with perennial understory 

competition, controlled the spread and thickening of existing juniper-pinyon stands. The understory vegetation controlled or regulated the incidence and spread offires, which, 

in turn, regulated the presence and distribution of juniper 

and pinyon (Tausch, this Proceedings; West, this Proceedings; Gruell, this Proceedings; Gottfried and others 1995). 

Heavy grazing by livestock o~er many years has resulted in 

community changes and the eventual loss of the native 

perennial understory and, in some locations, establishment 

of exotic annuals that now dominate some understories. 

These changes have resulted in lost or damaged archaeological sites (Chong 1993), reduction in deer and elk numbers 

(Short and McCullock 1977; Suminski 1993) and degredated 

watersheds (Roundy and Vernon, this Proceedings). 

Adjoining semiarid grass and shrublands underwent 

similar changes as desirable perennial species were eliminated or reduced in density and vigor by grazing. The loss of 

dominant perennial grasses and other understory species, 

and resulting absence or red uction in fire incident allowed 

for an increase injuniper and pinyon trees, and substantial 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Richard Stevens was Project Leader/Research Biologist (retired), Division 

of Wildlife Resources, Great Basin Experiment Station, Ephraim, UT 84627. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

tree invasion into many adjoining grass and shrublands 

(Aro 1975; Tausch, this Proceedings; West, this Proceedings; 

O'Brien and Woudenberg, this Proceedings). 

Removal or controlled use of livestock from depleted 

juniper-pinyon dominated areas will not facilitate the recovery of native vegetation, stabilize the soil, or return these 

areas to their pre-settlement conditions (Goodloe 1993; 

Stevens and Monsen, In press). Principle reasons are the 

absence of an adequate seed source and the competitive 

attributes of the pinyon-juniper trees. In order to return 

many juniper-pinyon areas to a more natural state, tree 

competition has to be reduced, a suitable seedbed has to be 

created, and sites will need to be properly seeded to adapted 

compatible species. 

Chaining __________ _ 

Native communities can only be reestablished if the density of pinyon and juniper is reduced and desired native 

species have an adequate seed bank or are seeded. Changes 

in tree density can range from near complete stand removal 

to limited thinning. Chaining and other mechanical treatments used to reduce tree density are substitute methods of 

natural tree control most frequently attained by wildfires. 

The objective of most improvement projects should not be to 

remove all trees, but to remove sufficient numbers to allow 

recovery ofthe understory species and to facilitate artificial 

seeding (Stevens and Monsen, In press). Tree removal, by 

whatever means is simply a technique used to change the 

seral status of many sites. 

Removal of undesirable, competing weedy trees can be 

accomplished in a number of ways. Twice-over anchor 

chaining, with 90 lb links, in opposite directions has been 

used extensively. Vse of cable or a chain oflighter links is 

satisfactory where it is desired to leave more trees and most 

shrubs. Once-over chaining may be adequate when sufficient understory remains, and trees are sparse and mature, 

and seeding is not required. Cabling is less effective than 

chaining in removing trees, but it disturbs less understory. 

There are three basic types of chain; smooth, Ely, and Dixie 

sager (Stevens, this Proceedings). 

Anchor chains are pulled behind two crawler tractors 

traveling parallel to each other. For maximum tree removal, 

chains cannot be dragged while stretched taught, but must 

be dragged in a loose, J-shaped, V-shaped, or half-circle 

pattern. The half-circle configuration provides the greatest 

swath width and lowest percentage tree kill. It is primarily 

used in mature, even-aged stands and when a low percent 

tree kill is desired. Tree kill increases as the width of the J 

or V-shaped pattern decreases. As the proportion of young 

trees change in a stand, chaining width should increase or 

decrease in order to achieve the desired amount of tree kill. 

285 
Chaining can be effectively used to regulate or manipulate 

a community without destruction of understory species. 

Chain link size, modifications to links, and placement of 

crawler tractor will determine disturbance severity to understory species. Types and size of chain and chaining 

practices can be regulated to retain most all existing species 

including threatened and endangered species, yet sufficiently reduce tree competition to facilitate seeding or promote natural recovery of understory species. Native 

seedbanks are not harmed by appropriate chaining. 

Not all juniper-pinyon sites support similar composition 

of understory species. A variety of herbaceous and woody 

plants exists in different amounts depending on degree of 

depletion, community site, and climatic conditions. Species 

composition of juniper-pinyon communities may be altered 

to a different seral status with and without the introduction 

of species attained by seeding. In some situations, juniperpinyon woodlands can be converted by only burning or 

chaining to reduce tree density. This is possible if sufficient 

native understory composition and density exists, and is 

capable of recovery following treatment (Jacobs and 

Gatewood, this Proceedings). 

Seeding 

Juniper-pinyon sites that have been void of understory 

species for many years will most likely lack a sufficient 

seedbank and natural recovery will not occur even if trees 

are removed (Poulsen and others, this Proceedings). Understory shrub and herbaceous species that have been weakened by heavy grazing and competition from tree encroachment normally bears very little seed, and may persist for 

years before eventually succumbing. Under these conditions, undisturbed stands of juniper-pinyon may exist for 

many years with little understory seed being added to the 

natural seedbank. Removal of competitive trees on many 

sites will result in a slow, erratic recovery of associated 

native species. Unless sites are artificially seeded, natural 

recovery is often ineffective. W'ithout sufficient understory, 

exotic weeds can become established and dominate the area. 

Juniper-pinyon restoration programs should be designed 

to allow for restoring native vegetation, and create stable 

communities. Converting juniper-pinyon communities to 

only an assembly of foreign species is not advisable. 

Under normal chaining conditions, suitable seedbeds are 

created to plant seeds of a number of species, having different seedbed requirements. The chain will create numerous 

micro sites and allow for shallow or deep planting depth 

requirements. In addition, seeds can be broadcast before or 

after chaining, to achieve the desired planting depth, surface compaction, and stand establishment (Stevens and 

Monsen, In press). 

Natural seeding of targeted native species can be promoted when chaining is conducted following seed production. Chaining also promotes sprouting of some species, and, 

if done at the correct season, favors their recovery and 

spread. Chaining and seeding can be conducted at the most 

appropriate season favoring establishment of the planted 

species. Fall seeding, over the majority ofthe Intermountain 

West, has proven to be the most ideal time to seed. Where 

spring seedings are employed, they need to occur prior to 

286 

mid-March. In southern Utah, southern Nevada, and northern 

Arizona, seeding just prior to the mid-July summer storms 

has resulted in good success (Stevens, this Proceedings). 

A majority of juniper-pinyon chainings and fires in the 

Intermountain West have been successfully aerially seeded. 

Most grasses and forbs and small seeded shrubs such as 

sagebrush, and rabbitbrush can be seeded successfully with 

both fixed-wing aircraft and helicopter. Helicopters generally do a better job of distributing seed over small or irregular areas. Downdraft from helicopters can somewhat separate seed in a mix by size and weight. There is a tendency for 

lighter seed to drift to the outer edge. When downed trees do 

not interfere, seed can also be covered successfully using 

drags or a pipe harrow. Single disk harrows, or similar light 

machinery, can also be used to cover the seed in open debrisfree areas. Care must be taken to ensure that seeds are not 

covered too deep and seedbeds are not too loose. Chaining, or 

equivalent treatments, are required to cover seed when 

burned sites are broadcast seeded. When this does not occur, 

seeding is best done on top of the first snow over disturbed 

soil, results may, however, be erratic. 

Rangeland type drills, especially those with multiple seed 

boxes and planting depth capabilities can be used to seed 

many species on clear large open areas. Seeds that are in 

short supply or those that require a firm seedbed can be 

seeded with a Hansen seed dribbler or thimble seeder 

mounted on the deck of a craw ler tractor. Seed is metered ou t 

onto the crawler tracks, the seeds are embedded in the soil 

by the tracks. When seeding species with very different 

seeding requirements, more than one seeding procedure 

may be required. Many species can be aerially seeded and 

then planted by chaining. Following chaining, the surface 

seeded species can then be aerially broadcast seeded. 

Chaining can be the first essential action in reestablishing 

native communities. The second essential action is properly 

seeding adapted, compatible species that will lead to community restoration. Some native species have been seeded 

for years, however, the number of native species seeded and 

pounds of seed seeded has generally been less in comparison 

to the seeding of exotic species. 

Following are a number of reasons or excuses given for not 

seeding natives more extensively: 

1. Little or no desire to seed natives. This is very common 

with individuals that are single resource oriented and those 

that are comfortable with doing business as they always 

have. 

2. Seed of few native species are available. People have 

perceived this and used it as a problem for years, however, 

seed of more and more native species are becoming available. Utah Division of Wildlife and U.S. Forest Service have 

put considerable effort into selecting native species and into 

promoting and developing native seed sources for restoration seedings (McArthur and Young, this Proceedings). Species being selected and promoted today include: 

Bluebunch wheatgrass 

Sheep fescue 

Prairie junegrass 

Mutton bluegrass 

Sandberg bluegrass 

Mountain bluegrass 

Needle-and -thread 

Thurber needlegrass 

Bottlebrush squirreltail 

Showy goldeneye 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 1-Number of native species seeded by Utah Division of 

Wildlife Resources, 1959 through 1996. 

Year 

Species 1959 1966 1979 1989 1995 1996 

Grasses 0 4 6 9 11 16 

Forbs 0 6 8 9 11 17 

Shrubs 8 16 22 20 18 18 

Total 8 26 36 38 40 51 

In 1959, Utah Wildlife Resources seeded only eight different native species (table 1). In 1996 they seeded 51 native 

species. 

Seed of a large number of natiye species is becoming 

available each year. A 1996 survey of all Utah seed companies with only five responses shows that seed of 113 native 

species were available and sold in 1996 (table 2). Species are 

being added yearly. Demand will determine the availability 

of native seed. 

3. Native seed is unavailable in sufficient volume. With 

some planning, this should not be an excuse or problem. 

Natives are becoming more available every year. Table 2 

shows that 530,8161b of native seed was sold by only five of 

Utah's 13 seed companies in 1996. Seed is available or will 

be available if there is a consistent demand. Amount of 

native seed seeded has increased significantly through the 

years. Utah Division of Wildlife Resources has moved from 

where native seed only accounted for less than 5 percent of 

the seed seeded in 1959 to over 47 percent in 1995 (table 3). 

In order for an agency to do this, they need to; a) develop a 

native attitude, b) plan ahead at least one season in advance 

so that basic seed needs are known, c) order seed ahead so 

that seed companies have sufficient time to acquire the seed, 

d) have a seed warehouse program and adequate seed 

inventory, e) manage lands for seed production, and D 

develop and implement seed collection permits and regulations that will allow for obtaining sufficient seed at a desirable price. 

4. Native species do not produce sufficient quantity of 

forage. Ifa manager's objectives are truly multiple resources 

and community and ecological restoration, then volume of 

livestock forage production will not be a major governing 

factor. It is not uncommon for the total production of a 

complete community to be equal to 01' exceed that of a few 

species seeding. Communities will have longer succulent 

periods, and respond more positively to fire and variations 

in precipitation, insects, and diseases than will few species seedings. 

5. Natives are difficult to establish. Natives may be 

somewhat harder to establish if they are not properly seeded. 

Most exotic grasses and forbs were agronomically selected. 

As such, they respond well to agronomic seeding requirement. Many managers try to employ exotic species seeding 

requirements on native and fail. Native species have evolved 

with differing seeding requirements, some have evolved 

with the seed being buried deep and others do best when 

seed is surface seeded on disturbed bare ground. Some 

species do best seeded in litter, where others establish best 

in bare ground. Seeding techniques have to match seeding 

requirements. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Table 2-Pounds of native seed sold in 1996 

by five Utah seed companies. 

Pounds of 

Grasses seed sold 

Bluegrass, Sandberg 1,144 

Bluegrass, Sherman big 2,500 

Brome, mountain 19,202 

Dropseed, sand 950 

Fescue, Idaho 123 

Fescue,sheep 9,950 

Foxtail, meadow 1,202 

Galleta 1,150 

Grama, blue 300 

Grama, sideoats 2,000 

Hair-grass, tufted 110 

Junegrass, prairie 105 

Needle-and-thread 620 

Needlegrass, green 2,865 

Needlegrass, Letterman 210 

Redtop 10 

Ricegrass, Indian 11,555 

Sacaton, alkali 2,000 

Squirreltail, bottlebrush 7,685 

Three-awn, purple 100 

Timothy, alpine 200 

Wheatgrass, bluebunch 9,552 

Wheatgrass, slender 14,400 

Wheatgrass, Snake River 15,000 

Wheatgrass, stream bank 11,850 

Wheatgrass, thickspike 27,305 

Wheatgrass, western 23,616 

Wildrye, beardless 100 

Wildrye, Great Basin 22,522 

Total 188,326 

Forbs 

Aster, blueleaf 356 

Aster, Engelmann 20 

Aster, Pacific 410 

Balsamroot, arrowleaf 625 

Balsamroot, cutleaf 140 

Beeplant-spiderflower 3,200 

Columbine 50 

Cowparsnip 70 

Eriogerons 300 

Eriogonums 100 

Fairwell to spring 100 

Flax, Lewis 3,965 

Gallardia 80 

Geranium, sticky 10 

Gilia 2 

Globemallow, desert 900 

Globemallow, gooseberryleaf 360 

Globemallow, munro 500 

Globemallow, scarlet 60 

Goldeneye, showy 530 

Helianthella, oneflower 60 

Ligusticum, Porter 20 

Louisiana sage 115 

Lupine, desert 58 

Lupine, mountain, silky, silver 2,681 

Marigold, desert 100 

Mulesear 140 

Paintbrush, Indian 10 

(con.) 

287 
Table 2 (Con.) 

Grasses 

Forbs 

Penstemon, Eaton-firecracker 

Penstemon, Palmer 

Penstemon, Rocky Mountain 

Penstemon, Rydberg 

Penstemon, thickleaf 

Penstemon, Wasatch 

Poppy, California 

Poppy, Iceland 

Sunflower, common 

Sweetanise 

Sweetvetch, Utah-northern 

Yarrow, western 

Total 

Shrubs 

Bitterbrush, antelope 

Bitterbrush, desert 

Buffaloberry, roundleaf 

Buffaloberry, silver 

Chokecherry 

Cliffrose 

Currant, golden 

Currant, wax 

Dogwood, redosier 

Elderberry, blue 

Elderberry, red 

Ephedra, green 

Ephedra, Nevada 

Eriogonum, Wyeth 

Greasewood 

Hopsage, spiny 

Mahogany, curlleaf mountain 

Mahogany, true mountain 

Rabbitbrush, Douglas 

Rabbitbrush, low 

Rabbitbrush, mountain rubber 

Rabbitbrush, white rubber 

Rose, Woods 

Sagebrush, black 

Sagebrush, silver 

Sagebrush, basin big 

Sagebrush, fringed 

Sagebrush, mountain big 

Sagebrush, sand 

Sagebrush, silver 

Sagebrush, Wyoming big 

Saltbush, Quail 

Saltbush, fourwing 

Saltbush, Gardner 

Saltbush, mat 

Saltbush, shadscale 

Serviceberry, Saskatoon 

Serviceberry, Utah 

Snowberry, mountain 

Sumac, Rocky Mountain 

Sumac, skunk bush 

Winterfat 

Total 

Grand Total 

288 

Pounds of 

seed sold 

40 

2,010 

500 

140 

20 

220 

2,000 

100 

5,900 

490 

597 

8,443 

35,422 

6,047 

900 

45 

10 

785 

802 

80 

120 

50 

400 

150 

1,605 

1,255 

10 

955 

180 

605 

830 

2,200 

1,600 

5,350 

11,765 

2,200 

405 

150 

20,230 

560 

22,522 

200 

400 

120,000 

100 

76,350 

4,200 

310 

14,250 

347 

675 

810 

350 

1,820 

5,445 

307,068 

530,816 

Table 3-Percentage of Total Pounds Seeded of Native and 

Introduced Species by Utah Division of Wildlife 

Resources; 1953-1996. 

Species 

Natives 

Introduced 

1959 

5 

95 

1966 

24 

76 

Year 

1979 1989 

38 

62 

46 

54 

1995 

47 

53 

1996 

40 

60 

There are native species whose seed viability lasts only a 

few days and others that retain good viability for 30 plus 

years. Seed dormancy, afterripening and need for scarification varies between species. These all need to be considered 

when seeding natives. 

Poor establishment is generally a result of poor action 

and management rather than species and seed characteristics. There is a great need for managers to not do things as 

they have always done them, but rather to gain new knowledge and experience and move forward into community 

restoration and sound ecological management. Good establishment occurs where seed is given every opportunity to 

germinate and establish. 

Successful native see dings occur: 

1. On sites where competition has been reduced sufficiently to allow for successful establishment of seeded species and recovery of on site endemic species. 

2. When species are seeded that are adapted to the site 

conditions. 

3. When species that are compatible with each other and 

with endemic on site species are seeded. 

4. When species are seeded into the ecological nitch they 

are most adapted. One cannot expect a late seral species to 

do well on a disturbed site. Pioneer species will establish and 

perform better on disturbed sites than will late seral species. 

5. When seed is planted in the proper season. Late fall 

and early winter are the most preferred time to seed. One 

needs to ask the question; when and how does each native 

species naturally seed and establish the most successfully? 

6. When seed is properly placed in the soil. Species seeding 

requirements vary between species. The most ideal seeding 

location and depth can range from surface to 3 to 4 inches 

deep, in a firm to loose seedbed and in or under litter or on 

exposed soil. 

7. When the right equipment and techniques are used to 

prepare the seedbed and to plant the seed. 

8. When on site endemic species are given every opportunity to express them self. Site preparation and seeding 

equipment and techniques need to favor the desirable endemic species rather than eliminate or harm them. 

Native communities can be restored through a combination of proper community management practices and proper 

seeding of compatible species ecologically adapted to the 

site and endemic communities. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Acknowledgments 

Funds were provided through Federal Aid in Wildlife 

Restoration Project W82R, Study 5 and Rocky Mountain 

Research Station, USDA, Forest Service, Provo, Utah. 

References __________________ __ 

Aro, R S. 1975. Pinyon-juniper woodland manipulation. In: Gifford, 

G. H.; Busby, F. E. eds. The pinyon-juniper ecosystem: A symposium. 1975 May; Logan, UT. Utah State University: 67-75. 

Chong, Geneva. 1993. Revegetation of pinyon-juniper woodlands 

with native grasses. In: Aldon, Earl F.; Shaw, Douglas W., 

technical coordinators. Managing pinyon-juniper ecosystems for 

sustainability and social needs; proceedings of the symposium. 

1993 April 26-30; Sante Fe, New Mexico, Gen. Tech. Rep. RM-236. 

Fort Collins, Co: U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Forest and Range Experiment Station. 34-41. 

Goodloe, Sid. 1993. The pinyon-juniper invasion: an inevitable 

disaster. In: Aldon, Earl F.; Shaw, Douglas W., technical coordinators. Managing pinyon-juniper ecosystems for sustainability 

and social needs; proceedings of the symposium. 1993 April.26-

30; Sante Fe, New Mexico, Gen. Tech. Rep. RM-236. Fort Collms, 

Co: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 153-154. 

Gottfried, G. J.; Swetnam, T. J.; Allen, C. D.; Betancourt, J. L.; 

Chung-MacCoubrey,AL.1995. Pinyon-juniperwoodl.ands~ Chapter 6. In: Finch, D. M.; Tainter, J. A, eds. Ecology, dIversIty and 

sustainability of the middle Rio Grande basin. Gen. Tech. Rep. 

RM-268. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment 

Station. 

Gruell, G. E. 1998. These Proceedings. Historical and modern roles 

of fire in pinyon-juniper. 

Jacobs, B. F.; Gatewood, R G. 1998. These Proceedings. Restoration 

studies in degredated pinyon-juniper woodlands ofnorth-central 

New Mexico. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

McArthur, E. D.; Young, S. A. 1998. These Proceedings. Development of native seed supplies to support restoration of pinyonjuniper sites. 

O'Brien, R A; Woudenberg, S. W. 1998. These Proceedings. Distribution of pinyon-juniper woodlands in Utah and Nevada from an 

inventory perspective. 

Poulsen, C. L.; Walker, S. C.; Stevens, R 1998. These Proceedings. 

Soil seed banking in pinyon-juniper with differing levels of tree 

cover and understory density, and composition. 

Round;, B. A.; Vernon, J. L. 1998. ~hese P~ocee?ings .. Wa.tershed values and conditions assocIated wIth pmyon-Jumper 

comm uni ties. 

Short, H. L.; McCulloch, C. Y. 1977. Managing pinyon-juniper 

ranges for wildlife. Gen. Tech. Rep. RM-47. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station. 10 p. 

Stevens, R 1998. These Proceedings. Mechanical chaining and 

seeding. 

Stevens, R; Monsen, S. B. In Press. Pinyonjuniper. In: Monsen, S. B.; 

Stevens, R, eds. Restoration and revegetation of western ranges 

and wildlands. U.S. Department of Agriculture, Forest Service, 

Gen. Tech. Rep. 

Suminski, Rita R. 1993. Management implications for mule deer 

winter range in northern pinyon-juniper. In: Aldon, Earl F.; 

Shaw, Douglas W., technical coordinators. Managing pinyonjuniper ecosystems for sustainability and social needs; proce.edings of the symposium. 1993 April 26-30; Sante Fe, New MexIco, 

Gen. Tech. Rep. RM-236. Fort Collins, Co: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest and Range 

Experiment Station. 133-139. 

Tausch, R J. 1998. These Proceedings. Transition ~nd t.hresholds: 

influences and implications for management m pmyon and 

juniper woodlands. . . 

West, N. E. 1998. These Proceedings. Distribution, composItIOn, 

and classification of current juniper-pinyon woodlands and 

savannas across western North America. 

289 
Thinning Versus Chaining: Which Costs 

More? 

James H. Chadwick 

Deanna R. Nelson 

Carol R. Nunn 

Debra A. Tatman 

Abstract-In 1990, 320 acres of pinyon-juniper were chained as 

part of a big game winter range improvement project in Spanish 

Fork Canyon. Areas were double-chained: units were chained in one 

direction, seed was broadcast aerially, and the units chained in the 

opposite direction. In conjunction with the chaining, 40 acres were 

thinned and seeded with the same mix in order to compare implementation costs and results between the two treatments. Trees 

were dragged and hand-piled in drainage ways and seed was raked 

into the soil so as to better simulate the effects of chaining. Per-acre 

cost for thinning was considerably greater than for chaining. 

During the mid to late 1980's local wildlife biologists 

became concerned by the rate at which critical winter range 

for mule deer and elk was being lost to the recent growth of 

communities along the Wasatch Front. As development 

encroached onto these areas, big game began to overuse the 

range still available to them. Wildlife biologists looked to 

nearby Spanish Fork Canyon for opportunities to improve 

early spring/late fall transitional range, as well as critical 

winter range in order to relieve pressure along the Front. It 

was decided that creation of small openings in dense pinyonjuniper stands would produce a mosaic-like effect, increasing forage and browse while maintaining adequate cover. 

Partners in the project believed that chaining was the most 

economical way to accomplish this. A thinning was performed as a comparison to chaining in order to determine 

which treatment was the most cost effective. Costs are evaluated and results compared between the two treatments. 

Methods 

Chaining 

In the fall of 1990, 320 acres of pinyon-juniper woodland 

scattered over five square miles were doubled chained and 

reseeded. The 11 units range in size from 20 to 60 acres. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

James H. Chadwick is Biological Technician, Uinta National Forest, 

Spanish Fork Ranger District, UT. Deana R. Nelson is Ecologist, Uinta 

National Forest, Provo, UT. Carol R. Nunn is Wildlife Biologist, Helena 

National Forest, Townsend Ranger District, MT. Debra A. Tatman is GIS 

Analyst/Coordinator, Eldorado National Forest, Placerville, CA. 

290 

Each unit was chained once, after which seed (a mixture of 

grasses, forbs and shrubs) was applied aerially, then chained 

again in the opposite direction. Browse species, having a 

relatively large seed, were applied with dribblers mounted 

on the dozers. All forb and grass species as well as smallseeded shrub species, were applied aerially. A 290-foot 

smooth anchor chain was pulled with two D-9 dozers. Great 

care was taken to assure a varied and natural looking edge 

effect as well as to minimize the amount of open space away 

from the edge. Many islands, drainage bottoms and ridgetops 

were left unchained for use as cover and travel routes. Large 

and mature pinyon pine and mountain mahogany were also 

left unchained in order for natural reseeding to occur. 

Thinning 

During the spring of 1991, 40 acres of the same pinyonjuniper woodland was seeded and thinned as one unit. Grass 

and forb seeds were broadcast by hand prior to the treatment. It was believed that the seed would be buried during 

the thinning through the activities of work crews. The Flame 

In Goes firecrew (Utah Department of Corrections) utilized 

chainsaws to thin the area, removing 25-40 percent of the 

stems per acre. The downed trees were then "lopped and 

scattered" with some trees being thrown into gullies to slow 

runoff and soil erosion. Once the thinning was complete, 

bitterbrush seeds were planted by hand. The unit was laid 

out so that the edge was varied and adequate travel routes 

were protected. The treatment protected healthy pinyon 

pine as well as valuable browse species like mahogany, oak, 

bitterbrush and sagebrush. 

Seed Mix 

Both treatment areas were seeded with the same mix in 

order to compare results between the two treatments. The 

seed mix was chosen for its ability to provide the quantity 

and quality of forage required to support big game during 

critical time periods, as well as provide food for a variety of 

small game and non-game species. Included in the mix were 

species known to establish quickly, in order to rapidly 

provide ground cover and readily bind soils to reduce erosion. The seed mix contained a variety of grasses, forbs and 

shrubs to mimic plant communities currently present on the 

site without using more than 50 percent non-native species. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
The seed mixes used were: 

Broadcast Mix 

Intermediate wheatgrass 

Hard sheep fescue 

Tall fescue 

Western wheatgrass 

Big bluegrass 

Basin wildrye 

"Regar" brome 

Crested wheatgrass 

Orchardgrass 

Blue lewis flax 

Palmer penstemon 

Small burnett 

Ladak alfalfa 

Yellow sweetclover 

Low elevation mountain big sagebrush 

White stemmed rubber rabbitbrush 

Dribbler Mix 

Antelope bitterbrush 

True mountain mahogany 

Curlleaf mountain mahogany 

Fourwing saltbush 

Cicer milkvetch 

In the thinned unit, only bitterbrush was planted. Seed 

was hand planted after thinning activities were completed. 

Results ------------------------------------

Costs 

The economics associated with each treatment were evaluated on a per acre basis, taking into consideration costs ofthe 

actual treatment, application of seed, and on-site supervision. The cost for thinning was found to be 44 percent greater 

than for chaining (fig. 1). It is important to note that figures 

represent only direct treatment costs. Costs for planning 

and layout and general administration (for example, resource identification and classification, interagency cooperation, environmental analysis, and monitoring) are not 

included. These costs represent a real and often large expense, but would be similar for each so are not presented 

here. Figures presented represent costs in 1990 and have not 

been adjusted to reflect inflation. 

Chainings 

Prior to treatment, units were dominated by pinyonjuniper and bare soil. Seven years after treatment total 

ground cover on the site had increased from 47 percent (prior 

to treatment) to 80 percent. Forage production within the 

chained unit increased from <20 Ibs per acre in 1990 to 

approximately 1000 Ibs per acre in 1997 (USDA Forest 

Service 1997). 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Treatment Costs per Acre 

250 

200 

150 

100 

50 

o-=----,-----~----,-----~----~--~ 

Chaining Thinning Clearcutting 

C ...... ____ T_r_e_a_tm_e_n_t_c_o_s_t __ D __ s_e_e_d_C_o_s_t ______ ) 

Figure 1-Comparison of costs ofthree techniques 

(chaining, thinning and clearcutting) to create small 

openings in pinyon-juniperwoodland. Values shown 

include only direct implementation costs ( materials, labor, contracts and supervision) and represent 

actual costs in 1990-1991. Costs for clearcutting 

were extrapolated from thinning costs. 

Thinning 

Thinning did not create an effective seed bed or provide for 

adequate seed burial. Mechanical means should be employed to create a seed bed and cover the seed, introducing 

additional costs to the treatment. 

The effects ofthinning seem to be dependent upon opening 

size. Increases in vegetative cover were only observed where 

larger openings were created. Opening size must be controlled by close supervision of thinning crews or extensive 

marking of the treatment areas, which increases the cost of 

the treatment. 

The opening size also effects the overall amount of acres 

treated and the lifespan of the treatment. Retreatment of 

the area would need to be completed sooner, at yet another 

cost to the overall project. 

Clearcutting 

Although a clearcut was not completed, figure 1 shows the 

cost estimate for this treatment. In order to evaluate 

clearcutting, costs were extrapolated from the cost of the 

thinning. The thinning in Spanish Fork Canyon removed, on 

average, 33 percent of the stems per acre. Assuming that a 

clearcut (removal of100 percent ofthe stems) would require 

three times more work than the thinning, the cost of this 

treatment is estimated to be 3-times the cost of thinning, or 

nearly 4 times the cost of chaining. 

291 
Conclusion -------------------------------- The intent of the Spanish Fork Canyon big game winter 

range enhancement project was to increase the quantity and 

quality of the forage available to big game animals during 

transition periods and critical winter months. The creation 

of openings in pinyon-juniper stands was needed to increase 

forage and browse production while maintaining cover. Two 

treatments were applied to the degraded habitat in order to 

compare the cost efficiency and benefit of each. Chaining 

seemed to provide an adequate seed bed and sufficient seed 

burial, which resulted in increased forage production. Thinning did not prepare an adequate seed bed or provide 

sufficient seed burial, and results were unsatisfactory. It is 

important to note that the costs and benefits can vary with 

soil type, tree density, and topography and many other local 

292 

factors. However, chaining was more effective than thinning 

in meeting the goals for the Spanish Fork Canyon winter 

range enhancement project and at a much lower cost. 

Acknowledgments 

We would like to extend our gratitude to Rocky Mountain 

Elk Foundation, Utah Division of Wildlife Resources, and 

Utah Sportman Alliance for their cooperation and support 

in this project. 

Reference __________ __ 

USDA Forest Service. 1997. Unpublished data. Uinta National 

Forest, Provo, UT. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Advantages and Effectiveness of 

Rollerchopping 

Douglas Sorensen 

Abstract-Rollerchopping is a mechanical method, using a 12-foot 

wide drum encased with large blades, that can be used to remove 

trees for improvement of site productivity. Advantages of 

rollerchopping over other land-clearance methods include treating 

slash, creating aesthetic sites, leaving soil undamaged, and leaving 

selected strips, groups, or individual trees. 

Thousands of acres of pinyon-juniper woodland have been 

treated by removing trees in order to increase the watershed 

qualities, produce livestock forage, and improve wildlife 

habitat. Typically, these areas were anchor chained and 

then seeded. Overtime, pinyon, juniper and sagebrush have 

again increased site dominance. For many ofthese sites, the 

ability to use fire as a treatment method is not feasible. 

Rollerchopping is an effective, relatively inexpensive mechanical method that can be used to again improve site 

productivity. 

Rollerchopping can be done anytime the treatment site is 

accessible and the soil will not be damaged by mechanical 

action. Even light snows should not stop the treatment. As 

with any mechanical treatment the site should not be worked 

if excessive soil moisture is present that would adversely 

impact the soil structure or cause rutting. Unlike prescribed 

fire, treatment can be done during or immediately following 

grazing. There is no need to rest the area before treatment. 

Rollerchopping provides excellent control of pinyon, juniper 

and sagebrush in the treated. area. 

The treatment layout caD: be designed to leave strips, 

groups or individual trees. The roller is maneuvered easily 

between groups of trees or even leave selected individual 

trees. The only limitation is the working width of the roller. 

In areas where hiding cover, archeological sites or special 

habitats must be preserved, rollerchopping has big advantages over other mechanical methods. 

In high visibility areas rollerchopping can provide irregular boundaries that are visually pleasing and enhance 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Douglas Sorensen is Rangeland Management Specialist, Beaver Ranger 

District, Fishlake National Forest, P.O. Box E, Beaver, UT 84713. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

wildlife habitats and cover. Pinyon and juniper are able to 

out-compete the herbaceous vegetation for the limited water 

and nutrients on the site. The effect of roller chopping on the 

vegetation is to crush and chop the brittle woody vegetation 

in order to allow the existing residual vegetation to increase 

its production. Because of the excellent seedbed preparation and water availability the site may be seeded to 

augment the existing plant composition and improve the 

site characteristics. 

The rollerchopping treatment is very effective in treating 

slash. The treatment does not leave piles or concentrations 

of slash requiring later treatment. Crushing the woody 

material greatly improves the water retention and availabilit yon the treated area. The litter cover will reduce or prevent 

overland flow and soil erosion. The water previously taken 

up by the trees is readily available for the grasses and forbs. 

Desirable browse, such as bitterbrush, sagebrush or 

fourwing saltbrush can be avoided. Root sprouting species 

are rejuvenated by the roller. On some sites, it may be 

desirable to treat root-sprouting species. 

The roller drum is 12 feet wide and 5 feet in diameter with 

steel blades 1 inch thick by 10 inches high and 12 feet long. 

The overall width is 14 feet. The roller weighs 16,000 pounds 

empty and can be filled with over 800 gallons of water. The 

replaceable blades will wear with use and must be replaced. 

These blades are typically the cutting blade used on some 

earth moving equipment. 

The rollerchopping limitations are the standard working 

limitations of the tractor. As a rule, steep slopes should be 

avoided. Tree size is generally not a problem. The dozer will 

push over larger trees for the roller to crush and chop. 

Obviously, if a site has many large trees, anchor chaining 

would be the preferred treatment. 

The working speed ofthe roller varies with site conditions 

such as slope, surface rock, and tractor horsepower. The 

roller should be able to travel at 2 to 3 miles per hour on most 

sites. At 3 miles per hour working speed, the roller can treat 

about 4.5 acres per hour. The cost of treatment varies from 

$25 to $30 per acre. 

The grazing activity immediately before and following the 

rollerchopping treatment will greatly infl uence the response 

and long term productivity ofthe site. For maximum production and site improvement, rest the site from grazing at least 

2 years following the treatment. 

293 
Restoration Studies in Degraded PinyonJuniper Woodlands of North-Central New 

Mexico 

Brian F. Jacobs 

Richard G. Gatewood 

Abstract-Small scale experiments were initiated in 1994, at two 

degraded pinyon-juniper (Pinus edulis Engelm. and Juniperus 

monosperma [Engelm.l Sarg.) woodland sites in north-central New 

Mexico, to evaluate the efficacy of resto~ation methodologies for 

reestablishment of native herbaceous cover. Results after three 

years post-treatment were highly significant: a primary, overstory 

reduction and slash mulching treatment produced two to sevenfold 

increases in total herbaceous cover relative to both controls and pretreatment condition. Secondary, soil surface preparation and seeding treatments appeared to confer no significant benefits over the 

primary treatment herbaceous response. 

Degraded pinyon-juniper (Pinus edulis Engelm. and 

Juniperus monosperma [Engelm.] Sarg.) communities occupy thousands of hectares within Bandelier National Monument and the adjacent Santa Fe National Forest in northcentral New Mexico. These woodland areas were inhabited 

during prehistoric times by Puebloan Indians who left behind an abundance of cultural remains. Overgrazing, loss of 

a fire regime and drought during the last 120 years are 

thought to be causative factors of the overstocked and 

degraded nature of many woodlands in this area. As increasing tree cover supplanted herbaceous cover, savanna like 

communities were gradually transformed into closed woodlands. Older growth trees are common in many of these 

woodland areas, but tree reproduction less than 120 years 

old accounts for much of the observed density. Interspaces 

between trees are characterized by scant herbaceous cover 

and exposed, rapidly eroding soils. Rapid soil loss in these 

degraded pinyon-juniper communities is unsustainable and 

ultimately threatens the integrity of thousands of prehistoric archeological sites embedded in the cultural landscape 

of north-central New Mexico. 

The current study was initiated in 1994 to evaluate the 

efficacy of potential methodologies for the restoration of 

degraded pinyon-juniper (Pinus edulis Engelm. and 

Juniperus monosperma [Engelm.] Sarg.) woodlands at 

Bandelier National Monument and on the adjacent Santa Fe 

National Forest. Specifically, we wanted to determine if a 

primary, overstory reduction and slash mulching treatment 

would yield a suitable herbaceous response and whether 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Brian Jacobs and Richard Gatewood are natural resource specialists at 

Bandelier National Monument, Los Alamos, NM 87544. 

294 

secondary, soil surface preparation and seeding treatments 

would enhance reestablishment of an effective ground cover. 

Previous work by Chong (1994) at Bandelier National 

Monument and by land managers on the Santa Fe National 

Forest (Elson, pers. comm.) set the stage for the current 

study. Chong (1994) demonstrated the importance of favorable microsites in the establishment of herbaceous plants 

from seed on degraded pinyon-juniper sites. She also noted 

that without the addition of seed material, no new grass 

plant establishment was observed (Chong, 1994) suggesting 

a depleted soil seed bank. Santa Fe National Forest land 

managers have repeatedly observed robust herbaceous responses following fuelwood harvests in pinyon-juni per woodlands, particularly when follow-up efforts were made to thin 

out smaller diameter trees and scatter the resulting slash 

(Elson, pers. comm.; Loftin, 1998). While numerous studies 

have documented an herbaceous response to overs tory thinning in pinyon-juniper systems (Arnold and Schroeder, 

1955; Bledsoe and Fowler, 1992), itis importantto assess the 

efficacy of restoration methodologies relative to specific site 

conditions and management objectives. 

Intensive grazing pressures, beginning around 1880, are 

thought to have reduced continuity of fine grass fuels, 

effectively preventing fire from propagating in pinyon-juniper woodlands (Gottfried and others, 1995) as well as in 

adjacent plant communities (Allen, 1989). Although pinyonjuniper communities are generally poor recorders of fire 

occurrence, evidence of periodic fire in these systems is 

provided by charcoal deposits in the soil and fire scars on 

woody remains and living trees (Gottfried and others, 1995). 

In addition, excellent fire history data documenting recurrent fire events are available from Ponderosa Pine communities immediately adjacent (Gottfried and others, 1995; 

Touchan and others, 1994). We suggest fire was an important process in maintaining the former savanna like structure of pinyon-juniper communities in our area. The thinning effects of periodic fire prior to 1880 and the subsequent 

loss of a fire regime would account for the pattern of widely 

spaced, older growth trees within a now dense woodland 

matrix of a much younger age. 

The loss of fire disturbance, initially as a result of overgrazing, and subsequently through active suppression 

(Gottfried and others, 1995), has had a profound influence on 

the dynamics of pinyon-juniper systems. Age class information from pinyon-juniper study sites in our area suggest an 

exponential increase in pinyon-juniper stem densities in 

former savanna areas beginning around 1880 (Allen, pers. 

comm.; Davenport and others, 1996; Gottfried and others, 

1995;). Pinyon and juniper also expanded their ranges, with 

USDA Forest Service Proceedings RMRS-P-9. 1999 
both species invading upslope into Ponderosa Pine dominated forests and juniper invading downslope into former 

shrub and grassland communities (Gottfried and others, 

1995). 

Active soil erosion on degraded pinyon-juniper sites during the last fifty years is clearly evidenced by exposed soils 

and bedrock, soil pedestals, lobes of active sediment and 

sediment accumulation behind fallen logs (Davenport, 1997). 

While previous episodes of erosion are documented in soil 

profiles from local pinyon-juniper sites (Davenport, 1997; 

Reneau, pers. comm.), the timing of the current erosional 

episode appears linked to historic land use practices. In 

addition, an extended drought during the mid-1950's is 

thought to have intensified competition for water in overstocked woodlands, perhaps reducing herbaceous cover below thresholds necessary to conta~n erosional processes 

(Wilcox and Breshears, 1995; Wilcox and others, 1996a,b). 

Occasional trunk remnants of Ponderosa Pine from individ uals killed during the 1950's drought can be found on both 

sites, but no live Ponderosa Pine is currently present within 

study site boundaries. 

Intensive characterization of erosional processes in a one 

hectare portion of a degraded pinyon-juniper woodland at 

Bandelier (Wilcox and others, 1996a,b) suggest average 

annual soil losses of 10,000 to 20,000 kg/ha, most of it 

occurring during intense thunderstorm events typical ofthe 

summer monsoons. On the basis of both soil erosion bridge 

and sediment catchment data, soil loss within degraded 

pinyon-juniper communities at Bandelier can be conservatively estimated at 2.5 cm per decade; an unsustainable rate 

given shallow soils with average depths of 1.0 to 12.0 dm 

(Davenport, 1997; Davenport and others, 1996; Wilcox and 

Breshears, 1995). 

Rapid soil loss in degraded pinyon-juniper communities 

threatens the integrity of the thousands of prehistoric cultural sites located within Bandelier National Monument. 

Well over three-quarters of the prehistoric sites at Bandelier 

National Monument occur within pinyon-juniper communities; of these cultural sites, nearly 99 percent have sustained 

erosional impacts (Mozzillo, in preparation). 

Despite the cessation of intensive livestock grazing pressure around 1940, in Bandelier National Monument and on 

portions of the Santa Fe National Forest, degraded pinyonjuniper communities appear to have little capacity to recover. Repeated measures of herbaceous cover in ungulate 

exclosures established in 1975 on degraded pinyon-juniper 

sites at Bandelier, suggest exclusion of grazing alone is 

insufficient to promote recovery of these systems. (Chong, 

1992). 

Overstocked with young trees and lacking an effective 

ground cover, degraded pinyon-juniper systems are poorly 

equipped to manage limited soil and water resources. These 

degraded communities can yield significant amounts of 

runoff and sediment, at various scales, particularly from 

bare ground interspaces during high intensity summer 

thunderstorms (Wilcox and others, 1996a,b). Freeze-thaw 

action on exposed soils is thought to facilitate erosional 

processes, both by inhibiting new plant establishment 

through root shear effects and by creating light textured 

crusts vulnerable to the forces of wind and rain. Harsh 

physical site conditions, characterized by exposed, nutrient 

poor soils, impose severe restrictions on the successful 

USDA Forest Service Proceedings RMRS-P-9. 1999 

establishment of new herbaceous plants. Soil seed banks 

appear to be depleted of perennial grass propagules and the 

depauperate grass individuals are incapable of producing 

viable seed in many years. With generally low herbaceous 

productivity, seed predation by birds, rodents, and harvester ants can be very efficient. High levels of mortality are 

common, in both germinating seed and young herbaceous 

seedlings. Herbivory of cool season grasses by native ungulates may limit abundance and productivity of these species 

relative to warm season grasses. 

At Bandelier, the selection of restoration methodologies is 

constrained by self-imposed restrictions designed to protect 

cultural, natural, and wilderness resource values (Sydoriak, 

1995). Overstory reduction must be accomplished using 

minimum tools and techniques that are sensitive to multiple 

park resources. Rough terrain, high cultural site density, 

and the presence of designated wilderness essentially preclude mechanized ground disturbing activities (such as 

chaining, drilling and other agronomic techniques utilizing 

heavy equipment) typically associated with large scale restoration efforts. Planting methodologies for seed material 

are generally limited to hand methods. All plant materials 

must be locally native, requiring custom production at 

considerable expense. 

Methodology 

Two degraded pinyon-juniper sites were included in the 

current study; one located on Frijoles Mesa within Bandelier 

National Monument and a second on Garcia Mesa in the 

adjacent Santa Fe National Forest. Study sites are located 

at the upper end ofthe pinyon-juniper zone on gently sloped 

mesas between 1980 m (6600 ft) at Frijoles Mesa and 2160 

m (7200 ft) at Garcia Mesa. Canopy closure ranged from 23.0 

to 60.0 percent, with herbaceous cover ranging from 5.0 to 

15.0 percent, litter ranging from 38.0 to 84.0 percent and 

bare soil ranging from 7.0 to 56.0 percent. Soils are derived 

from volcanic ash deposits and are generally shallow and 

poorly developed (Davenport, 1997; Davenport and others, 

1996; Wilcox and Breshears, 1995). Precipitation increases 

with elevation and ranges from around 40.0 cm. (16 in.) at 

the Frijoles Mesa site to nearly 50.0 cm. (20 in.) at the Garcia 

Mesa site (Wilcox and Breshears, 1995). Summer thunderstorms account for nearly half ofthe annual rainfall; winter 

snows are variable in depth and persistence (Wilcox and 

Breshears, 1995). 

Experimental Design 

The experiment consisted of 18, 15m2 plots at each of two 

sites. Because of constraints in implementing this study, the 

primary, overstory reduction and slash mulching treatment 

was assigned to 15 contiguous plots, in a non-random fashion, with the remaining three plots serving as controls. 

Evaluation of the primary treatment relative to controls, is 

considered separately from the secondary treatment. 

For the purposes of evaluating secondary treatments, the 

15 plots within the bounds of the primary, overstory reduction and slash mulching treatment, were divided into three 

blocks of five plots each. Within each block, plots were 

randomly assigned one of five secondary treatment 

295 
combinations: slash mulch only; slash mulch + imprinting; 

slash mulch + seeding; slash mulch + imprinting + seeding; 

or slash mulch + raking + seeding. 

Data Collection Protocols 

Herbaceous cover was measured as an indicator of system 

response to treatment, since these data can be reliably 

collected by a seasonal workforce and are indicators of 

available soil moisture and rates of soil erosion. Changes in 

soil surface cover (that is vegetation, litter, bare soil) were 

measured using a modified University of New Mexico, Long 

Term Ecological Research program design; vegetation data 

was collected by species and growth form and included basal 

intercept and canopy cover components. Two 21.21 meter 

vegetation transects were permanently established in each 

plot for a total of 42.42 m sampled per plot. Pre-treatment 

data was collected from both study sites during the fall of 

1994. Year 2 and 3 post-treatment data was subsequently 

collected at each study site during the fall of 1996 and 1997. 

These data were compiled and summarized using the Statistical Package for Social Sciences. Large and small scale 

repeat photos were taken along the vegetation transects to 

provide additional visual documentation of treatment 

response. 

Restoration Treatments 

The primary, overstory reduction and slash mulching 

treatment was applied to both sites in the spring of 1995. 

Overstory reduction treatment was applied using chainsaws. 

Bledsoe and Fowler (1992) suggested overstory reduction of 

pinyon-juniper woodlands through selective thinning, as 

compared with agronomic techniques such as chaining, can 

meet multiple management objectives. Main limbs were 

lopped off and the trunk was flush cut at the base. The 

resulting slash, lopped branches and trunk sections, were 

then scattered preferentially.into the bare interspaces to 

serve as a rough mulch. On the basis of land manager 

recommendations (Elson, pers. comm.), previous experimental restoration work (Bledsoe and Fowler, 1992), spatial 

patterns of older growth trees, and water relation studies in 

pinyon-juniper systems (Breshears and others, 1997), a 

spacing between mature tree individuals offrom 15 to 20 m 

was considered optimal for restoration of former pinyonjuniper savanna types in the study area. Following these 

recommendations, we elected to remove all of the tree 

canopy within and immediately adjacent to individual plots 

for the purposes of this small scale experiment. 

Secondary soil surface preparation and seeding treatments were applied to bare soil areas of both sites during the 

summer of 1995. Soil surface preparation techniques applied prior to seeding included: no soil surface preparation, 

light raking, and imprinting. Raking was accomplished 

using a council fire rake to cut shallow (1-2 cm deep) furrows 

perpendicular to the slope. Imprinting was accomplished 

using custom made, hand implements to create a pattern of 

sloped depressions (5 cm deep) on moist soil surfaces. Imprints provide temporary catchments for seed, litter, soil 

and water and thus may serve as favorable microsites for 

germinating plant materials. Seed material was applied at 

296 

a rate of 1291 seeds/m2 and consisted of a mix of blue 

gramma (50 percent), little bluestem (30 percent), and sand 

dropseed (20 percent). The relatively high seeding rate was 

used in an attempt to compensate for anticipated losses due 

to seed predation, seed mortality and marginal seedbed 

preparation. Seeding was accomplished by broadcasting the 

seed mix onto designated treatment plots subsequent to soil 

surface preparation. Loose dirt was lightly brushed back 

into the furrows cut on raked plots. 

Results __________ _ 

Primary Treatment 

A comparison of the primary, overstory reduction and 

slash mulching treatment to controls suggests that exposed 

soil coverage decreased by a mean of 222.0 percent at the 

Frijoles Mesa site and 200.0 percent at the Garcia Mesa site 

(fig. 1a,b). Total herbaceous cover had a mean increase of 

773.0 percent at Frijoles Mesa and 241.0 percent at Garcia 

Mesa, by the third year post-treatment (fig. 1a,b). Grass 

cover increased 446.0 percent at Frijoles Mesa and 179.0 

percent at Garcia Mesa (fig. 1c,d), while forbs increased 

1267.0 percent at Frijoles Mesa and 705.0 percent at Garcia 

Mesa (fig. 1c,d). The difference in relative contributions of 

forbs and grasses at the two sites may be due to the initially 

high grass cover at Garcia Mesa (25.0 percent) as compared 

with Frijoles Mesa (6.0 percent). The low initial grass cover 

at the Frijoles Mesa site may have provided more opportunities for annual and biennial forbs to establish. 

Secondary Treatment 

Analysis of the secondary, soil surface preparation and 

seeding treatments suggest that there was no significant 

increase in total grass cover over the primary treatment 

response (fig. 2). While Blue Grama (Bouteloua gracilis 

[H.B.K.] Lag.) showed a mean increase of 252.0 percent 

cover on seeded versus 119.0 percent cover on unseeded 

plots, this increase was apparently offset by contributions 

to total grass cover on unseeded plots by other non-seeded 

species (fig. 2). The other two seeded species, Little Blue 

Stem (Schizachyrium scoparium [Michx] Nash) and Sand 

Dropseed (Sporobolus cryptandrus [Torr.] Gray), had mean 

increases ofless than 1.0 percent across both sites. 

Discussion __________ _ 

Additional work is clearly needed to more completely 

understand the mechanisms responsible for the observed 

herbaceous response. Breshears and others (1997) provide 

evidence to support shallow water harvest by one-seed 

juniper from intercanopy spaces. Bledsoe and Fowler (1992) 

document an increasing herbaceous response to decreasing 

densities of overstory trees and report no significant increases in grass production without a minimum two-thirds 

overstory thinning. Preliminary greenhouse studies conducted at Bandelier support the benefits oflitter and slash 

as moderators of soil moisture and temperature; growth 

performance of blue gramma seedlings was significantly 

USDA Forest Service Proceedings RMRS-P-9. 1999 
90 

80 

70 

60 

~ 50 ... 

CII 

> 

0 40 0 

30 

20 

10 

0 

80 

70 

~ 60 

... 

CII 50 > 

0 

0 40 

:, 30 

20 

10 

0 

Control Treatment Control Treatment 

Exposed Soil Total Herbaceous 

Cover 

70 

Frijoles Mesa C 60 

50 

C 40 

... 

CII 

> 

0 30 0 

20 

10 

Garcia Mesa 0 60 

50 

~ 40 

... 

CII 

> 30 0 

0 

20 

10 

0 

Control Treatment Control Treatment 

Forbs Grasses 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Figure 1-Comparisons of the primary, overstory 

reduction and slash mulching treatment (n = 15) to 

control (n = 3) using four cover components measured at Frijoles Mesa (Graphs A and C) and 

Garcia Mesa (Graphs B and D). The clustered bars 

represent three years of measurements: 1994 

(pre-treatment), 1996 (two years post-treatment), 

and 1997 (three years post-treatment). Graphs A 

and B compare treatment effects on exposed soil 

and total herbaceous cover across both sites. 

Graphs C and D compare the forb and grass 

response between control and primary treatment 

plots for each site. The standard error bars are 

times one standard error. 

~.------------,-------------------------------~ 

9r-----------L-------~------~--------+_----~ 

~r-H!H------_4~------i~M------~tH-----~miH----~ 

~ 

~ 30 o 

(J 

20 

10 

Grass Grama Grass Grama 

Sl SIS 

Figure 2-Comparisons of total grass cover 

among secondary, soil surface preparation and 

seeding treatment combinations, for each year 

of measurement, and relative to one of the 

seeded species, blue grama (Bogr). Treatment 

codes: S = Slash only; SI = Slash Mulch + 

Imprinting; SIS = Slash Mulch + Imprinting + 

Seeding; SRS = Slash Mulch + Raking + Seeding. Standard error bars are times one standard 

error. 

297 
enhanced by litter and! or slash mulching treatments 

(Snyderman and Jacobs, 1995). Watershed level restoration 

studies underway at Bandelier National Monument are 

attempting to correlate the herbaceous response to overstory reduction and slash mulching treatment with soil 

moisture and soil erosion. 

We suggest that tree overstory removal reduces competition for limited water and nutrient resources while the 

scattered slash provides benefits to exposed soils: reducing 

runoff and sediment transport, increasing infiltration and 

soil moisture, moderating soil temperature, freeze-thaw and 

evaporation, redistributing nutrients, and mitigating grazing impacts. Combined, these effects create favorable 

microsites for increased productivity of remnant herbaceous 

plants as well as for germination, establishment and growth 

of new individuals from seed. 

High seed loss in secondary treatments, from some combination of predation and mortality, was evident at both sites 

based on seedbank analysis at one, three, and twelve weeks 

post-seeding (J acobs and Snyderman, 1995). Marginal planting techniques, which did not effectively provide seed with 

good soil contact, combined with uneven precipitation patterns may have been responsible. Slash mulch was observed 

to be effective in keeping wind and rain from transporting 

broadcast seed off ofindividual plots. Intense seed predation 

by harvester ants was observed at the Frijoles Mesa site, 

beginning soon after application and continuing until effective rain either concealed seeds or stimulated germination 

several weeks later. Surprisingly, loss of seed was also high 

at the Garcia Mesa site, despite the apparent absence of 

harvester ants and occurrence of effective precipitation 

within several days of planting. 

Acknowledgments ______ _ 

We would like to thank the eighteen Student Conservation Assistants who supported this study through their 

cumulative seventy-six months pffield work over a four year 

period. David Snyderman, Craig Allen and Sam Loftin 

provided valuable technical assistance. This study received 

financial support from the Challenge Cost Share Program of 

the National Park Service, the Friends of Bandelier, the 

Student Conservation Association, and Bandelier National 

Monument. 

References ------------------ Allen, C. D. 1989. Changes in the landscapes of the Jemez Mountains. Ph.D. dissertation, Univ. of Calif, Berkeley, CA 

Arnold, J. F. and Schroeder, W. L. 1955. Juniper control increases 

forage production on the Fort Apache Indian Reservation. USDA 

Forest Service, Rocky Mountain Forest and Range Experiment 

Station Paper No. 18, Fort Collins, CO. 

298 

Bledsoe, F. N. and Fowler, J. M. 1992. Economic evaluation of the 

forage-fiber response to pinyon-juniper thinning. New Mexico 

State University Agricultural Experiment Station Bulletin 753, 

Las Cruces, NM. 

Breshears, D. D., Myers, O. B., Johnson, S. R, Meyer, C. W. and 

Martens, S. N. 1997. Differential use of spatially heterogeneous 

soil moisture by two semiarid woody species: Pinus edulis and 

Juniperus monosperma. J. Ecology. 85:289-299. 

Chong, G. W. 1994. Recommendations to improve revegetation 

success in a pinyon-juniper woodland in New Mexico: a hierarchial approach. M.S. thesis, Univ. of New Mexico, Albuquerque, 

NM. 

Chong, G. W. 1992. Seventeen years of grazer exclusion on three 

sites in pinyon-juniper woodland at Bandelier National Monument, New Mexico. Unpublished report, Bandelier National 

Monument, Los Alamos, NM. 

Davenport, D. W. 1997. Soil survey of three watersheds on South 

Mesa. Unpublished report, Bandelier National Monument, Los 

Alamos, NM. 

Davenport, D. W., Wilcox, B. P. and Breshears, D. D. 1996. Soil 

morphology of canopy and intercanopy sites in a pinon-juniper 

woodland. Soil Sci. Soc. J. 60:1881-187. 

Gottfried, G. J., Swetnam, T. J., Allen, C. D., Betancourt, J. L. and 

Chung-MacCoubrey,A L.1995, Pinyon-juniper woodlands, Chapter 6, in: Ecology, diversity and sustainability of the middle Rio 

Grande basin, Finch, D. M. and Tainter, J. A, eds., USDA, Forest 

Service, Rocky Mountain Forest and Range Experiment Station, 

General Technical Report, RM-268. 

Jacobs, B. F. and Snyderman, D. 1995. Restoration Studies. Unpublished report, Bandelier National Monument, Los Alamos, NM. 

Loftin, S. R 1998. Initial response of soil and understory vegetation 

to a simulated fuelwood cut of a pinyon-juniper woodland in the 

Santa Fe National Forest. In: Monsen, S. B., Stevens, R, Tausch, 

R J., Miller, R and Goodrich, S., eds. Proceedings: ecology and 

management of pinyon-juniper communities within the interior 

west. 1997 Sept. 15-18, Provo, UT. USDA, Forest Service, Intermountain Research Station, General Technical Report INT-OOO. 

Ogden, UT. 

Mozzillo, E. 0., in preparation, Management summary of the 

Bandelier archeological survey. Unpublished report, Bandelier 

National Monument, Los Alamos, NM. 

Sydoriak, C., ed. 1995. Resources management plan. Unpublished 

report, Bandelier National Monument, Los Alamos, NM. 

Touchan, R, Allen, C. D. and Swetnam, T. W. 1994. Fire history and 

climatic patterns in Ponderosa pine and mixed-conifer forests of 

the Jemez Mountains, northern New Mexico. In: Fire effects in 

southwestern forests, Proceedings of the second La Mesa Fire 

symposium. USDA, Forest Service, Rocky Mountain Forest and 

Range Experiment Station, General Technical Report, RM-286. 

Wilcox, B. P., and Breshears, D. D. 1995. Hydrology and ecology of 

pinyon-juniper woodlands: conceptual framework and field studies. In: Desired future conditions for pinon-juniper ecosystems, 

1994 August 8-12, Flagstaff, AZ: USDA Forest Service, Rocky 

Mountain Forest and Range Experiment Station, General Technical Report, RM-258. 

Wilcox, B. P., Newman, B. D., Allen, C. D., Reid, K. D., Brandes, D., 

Pitlick, J. and Davenport, D. W. 1996a. Runoff and erosion on the 

Pajarito Plateau: Observations from the field. New Mexico Geological Society Guidebook, 47th Field Conference, Jemez Mountain Region, Los Alamos, NM. 

Wilcox, B. P., Pitlick, J., Allen, C. D., and Davenport, D. W. 1996b. 

Runoff and erosion from a ra pidly eroding pinyon -j uni per hillslope. 

In: Advances in Hillslope Processes. Vol. 1. eds: M.G. Anderson 

and S.M. Brooks. John Wiley and Sons LTD. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
The Influence of Anchor-Chaining on 

Watershed Health in a Juniper-Pinyon 

Woodland in Central Utah 

M. E. Farmer 

K. T. Harper 

J. N. Davis 

Abstract-In 1990 the U.S. Forest Service anchor chained and 

seeded 121 ha of juniper-pinyon woodland in Spanish Fork Canyon. 

Twenty, 10 m2 runoff-plots were established in 1991, to quantify 

anchor chaining's effect on runoff and soil erosion. Plots were 

paired, one in the chained area and one on comparable terrain and 

soil type in the untreated juniper-pinyon woodland. Each enclosed 

runoff-plot channels runoff water and suspended sediments into 

collection containers. During five years of data collection, unchained plots produced 5.8 times more runoff and 9.2 times more 

sediment than chained plots. Ground cover values for runoff plots 

show that vegetation increased from 27.1 percent in 1991 to 

41.3 percent in 1995 on chained plots, while litter increased from 

22.6 percent to 51.5 percent during the same time period. Vegetation cover on untreated plots varied from 7.5 percent in 1991 to 

3.4 percent in 1995. Litter cover averaged 18 percent. Results 

indicate that anchor chaining significantly reduced runoff and soil 

erosion by providing more protective ground cover. 

Juniper-pinyon woodlands are an important rangeland 

type in the western United States where it currently covers 

about 24.3 million hectares. In Utah, Juniper-pinyon woodlands cover approximately 6 million hectares. These woodlands have greatly expanded their distribution in the past 

150 years because of effective .fire control and heavy grazing 

by domestic livestock (West 1984). Without competition 

from a vigorous understory of grasses, forbs and shrubs and 

occasional wild fires, pinyon-juniper woodlands have become more dense and claimed much of the available nutrient 

and water resource previously used by a heavier cover of 

understory plants (Doughty 1986). Areas dominated by 

pinyon -j uni per prod uce little useable forage for wildlife or 

domestic grazers, and the bare inters paces are prone to 

erode during high intensity summer storms. Juniper and 

pinyon trees can often survive for 600 to 1000 years. Without 

some sort of mechanical removal, they may dominate a site 

for years and put at risk soils that support the ecosystem 

(West 1984). 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

M. E. Farmer is a Range Science Specialist, Utah Department of Agriculture, 735 N 500 E, Provo, UT 84606. K. T. Harper is a Professor in the 

Departmen t of Botany and Range Science, Brigham Young University, Provo, 

UT 84602. J. N. Davis is a Research Biologist, Utah Department of Wildlife 

Resources, 735 N 500 E, Provo, UT 84606. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Anchor chaining is a tree removal technique that has 

been used for the past 50 years. It is an economic method of 

converting juniper-pinyon woodland to vegetation rich in 

herbaceous perennial plants similar to that existing at the 

time of settlement of the region by European peoples. Many 

land managers have long assumed that reducing tree cover 

and encouraging grass, forb and shrub cover had a positive 

effect on infiltration, runoff and soil erosion on watersheds 

heavily dominated by juniper and pinyon, but quantitative 

data to support that assumption are uncommon. The purpose ofthis study is to quantitatively document the influence 

of anchor chaining on watershed health in juniper-pinyon 

woodland. 

Methods 

To determine the effects of chaining on runoff and soil 

erosion, 10 paired, 10 m2 runoff-plots were placed, one in the 

chaining and one in a comparable unchained area. The 

enclosed plots channel runoff water and suspended sediments down slope into a pipe connecting a series of covered 

containers. A storage rain gauge was also placed near each 

plot to estimate precipitation on the plot. Runoff water was 

collected periodically and its volume recorded. Sediments 

were collected, weighed, oven dried and re-weighed. Water 

content in sediment samples was added to the runoff total. 

Ground cover values were estimated using a modified 

Daubenmire (1959) cover estimation procedure. Percent 

cover of vascular plants, bare ground, rock, litter and cryptogamic plants was estimated annually at each runoff-plot. 

Results ---------------------------------------

All runoff plots were placed during the summer of 1991. 

Data were collected from August through October of that 

year. During that period, untreated control plots produced 

an average of nearly 6 times more runoff and 9 times more 

sediment than chained plots. In 1992 data were recorded 

from May through October. Control plots, during that six 

month period, generated an average of 51/2 times more 

runoff and over 6 times more sediment than the chained 

plots (fig. 1 and 2). During the summer (May-October) of 

1993, control plots produced 3 times more runoff and over 

6 times more sediment. 

In the first summer after chaining, chained plots averaged 

27.1 percent vegetative cover, compared to 6.2 percent on 

untreated plots (table 1). Protective ground cover consisting 

of vegetation and litter, averaged 49.7 percent on chained 

299 
80 

70 

60 

50 

... 

~40 

:::J 

30 

20 

Il 

v': k/ 

[/i 

~ Legend 

I ~ control 

: 

lSI chained 

/'! 

1,J//1 

. ~ 

~ 

;4 

-

I Q .115.7 

(/~ 

~ ~ •• / ./~~ 

1...,.;1 ~ 

I 

~, 

I-

~ 10 

1991 1992 1993 

Figure 1-Average liters of summer runoff from 

1991 to 1995. Each year's total is an average of 10 

measurements. 

1995 

plots and 20.9 percent on control plots. In 1992, vegetative 

cover averaged 43.3 percent on chained plots and 7.3 on 

control plots. Protective ground cover averaged 70.2 percent 

on chained plots while control plots averaged 28.3 percent. 

By 1995 vegetative cover on chained plots averaged 41.3 

percent and protective cover (vegetation and litter) averaged 

92.8 percent. Untreated control plots averaged only 3.4 

percent vegetation cover and 18.2 percent protective cover. 

Discussions _________ _ 

The primary forces which are related to water erosion are, 

raindrop energy and surface runoff, which remove and 

transport soil particles (Blackburn and others 1986). Vegetation is important in impeding overland flow and reducing 

//// 

800 -

./' 

~/ ~ 700 ~ 

600 

./'~/ 

J//I 

500 Legend 

~ control 

400 - ~ chained 

300 j.,/ 

J// V 200 

J/ 

V/ Jl08 

/ c:s:.::: 

---'?? 

~ ~ .~~ 

100 

a 1991 1992 1993 1994 

Figure 2-Average grams of sediment yield from 

10 plots during the summers of 1991-1995. 

300 

,.---

~ / .. ~ / 

1995 

Table 1-Relative percent ground cover of control and chained runoff plots. 

Each year's total is an average of 10 measurements. 

Unchained plots 1991 1992 1993 1994 1995 Average 

Bare ground 46.6 31.6 39.3 50.6 43.8 42.4 

Rock 31.1 40.1 33.5 25.1 33.5 32.7 

Litter 14.7 21.0 19.6 19.4 14.8 17.9 

Vegetation 7.5 7.3 7.6 4.8 3.4 6.1 

Chained plots 

Bare ground 43.1 25.1 19.5 27.1 15.4 26.0 

Rock 7.2 4.7 6.9 3.8 13.7 7.3 

Litter 22.6 26.9 37.9 38.1 51.5 35.4 

Vegetation 27.1 43.3 35.6 31.0 41.3 35.7 

raindrop energy. Blackburn and others (1986) state that 

the amount of vegetative cover is the primary erosion controlling factor. Control areas on the Spanish Fork Site 

during the study period, contained an average of6.1 percent 

vegetation cover, 60 percent of which was tree canopy cover. 

Simanton and others (1991) discovered that the significance of canopy cover was small compared to ground cover in 

soil erosion prediction models. Khan and others (1988) found 

that as canopy height increases the soil erosion rate also 

increases. Ground cover of understory vegetation is most 

effective at reducing soil erosion. Anchor chained sites in the 

Spanish Fork study provided more uniform protective vegetation cover closer to the ground surface than untreated 

juniper-pinyon sites. 

Conclusions _________ _ 

Over the five year period of study, Anchor Chaining 

allowed vegetative cover to increase 6 times on the average 

plot and litter cover to increase an average of 2 times. 

Runoff, on the chained plots, was reduced an average of 

6 fold and erosion reduced an average of9 fold. Results show 

that anchor chaining significantly reduced runoff and erosion by providing more protective ground cover. 

35~--------------------------===========-----

304---------------------------

25~--------------------------

~20J---------------------------

o 

u 

<fl. 15 

104---------------------------V 

Unchained 

• Grass fZI Forb • Shrub 

Chained 

~ Tree 

Figure 3-Average relative percent vegetation cover by 

class of unchained and chained runoff plots from 1991-94. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Acknowledgments 

This work was facilitated in active cooperation with the 

Brigham Young University, Utah Division of Wildlife Resources, USDA Forest Service, Uinta National Forest, and the 

Intermountain Research Station, Shrubland Biology and 

Restoration Research Work Unit. Research was partially 

funded by Pittman Robertson Agreements W-82-Rand W-135-R. 

References ---------------------------------- Blackburn, W. H., T. L. Thurow and C. A. Taylor, Jr. 1986. Soil 

erosion on rangelands. In: Proceedings, Range Monitoring Symposium, Society of Range Manage. Denver, CO: 31-39. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Daubenmire, R. 1959. A canopy coverage method of vegetational 

analysis. Northwest Sci. 33: 43-66. 

Doughty, J. W. 1987. The problems with custodial management of 

pinyon juniper woodlands. In: Proceedings, Pinyon-juniper 

Conference, USFS Gen. Tech. Report INT-215: 29-33. 

Khan, M. J., E. J. Monke, and G. R. Foster. 1988. Mulch cover 

and canopy effect on soil loss. Trans. of the Amer. Soc. Agr. 

Engr. 31: 706-711. 

Simanton, J. R., M. A. Weltz, and H. D. Larsen. 1991. Rangeland 

experiments to parameterize the water erosion prediction 

project model: vegetation canopy cover effects. J. Range Manage. 44(3): 276-282. 

West, N. E. 1984. Successional patterns and productivity potentials 

of pinyon-juniper ecosystems. In: Developing Strategies for Rangeland Management. Westview Press, Boulder: 1301-1332. 

301 
Impacts of Vegetative Manipulations on 

Sediment Concentrations from PinyonJuniper Woodlands 

Vicente L. Lopes 

Peter F. Ffolliott 

Malchus B. Baker, Jr. 

Abstract-This paper reports on relationships between suspended 

sediment concentrations and streamflow discharges from pinyonjuniper watersheds subjected to cabling treatments and applications of herbicides. These relationships are compared to relationships from a control watershed that represents untreated conditions 

to provide a basis for describing the effects of pinyon-juniper 

conversions on sedimentation processes. The effects are further 

analyzed by separating the data sets on the basis of streamflow 

generation mechanisms, that is, snowmelt-runoff events and highintensity, short-duration convectional rainfall events. Findings 

from the study indicate that suspended sediment concentrations, 

above a threshold discharge, increased as a result of the cabling 

treatment, while no change in sediment concentrations was observed as a result of the herbicide treatment. These results improved on earlier evaluations of the impacts of conversion treatments in the pinyon-juniper woodlands on suspended sediment 

discharges. 

Pinyon-juniper woodlands occupy large areas in the Interior West ofthe United States. Management of these ecosystems has been controversial, however, because their hydrology has been a concern. Rates of erosion have accelerated in 

recent years and, as a consequence, extensive areas have 

unsatisfactory soil and water conditions (Gottfried and others 1995). This assessment has been largely based on evidence of surface and gully erosion, soil compaction, and 

vegetative indices. 

The decline in watershed condition has been attributed to 

increases in overs tory tree densities, and corresponding 

decreases in understory grasses, forbs, and half-shrubs, 

which provide a protective cover on soil surfaces (Gottfried 

and others 1995). Overstory trees have been removed from 

many sites in the hope of remedying this situation by 

encouraging the production of understory plants. Another 

possibility is that the observed erosion is a residual of past 

land-use practices, and causes of erosion are more complex. 

The controversy over the hydrology and erosional dynamics in pinyon-juniper ecosystems has generated a number of 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Vicente L. Lopes is Assistant Professor, and Peter F. Ffolliott is Professor, 

School of Renewable Natural Resources, University of Arizona, Tucson, AZ 

85721. Malchus B. Baker Jr. is Research Hydrologist, Rocky Mountain 

Research Station, USDA Forest Service, Flagstaff, AZ 86001. 

302 

research studies (Gifford 1975, Wright and others 1976, 

Baker 1982, Wilcox 1994, Lopes and others 1996). As part of 

a general research effort to study the hydrologic and sediment-transport regimes of watersheds, the relative magnitudes of sediment exports are being analyzed in relation to 

watershed condition, streamflow-generation mechanisms, 

and land management activities. Sediment rating curves, 

developed to describe relationships between the amount of 

sediment in suspension and streamflow discharge, can be 

used to estimate the effects of management activities on 

suspended sediment (Brooks and others 1997, Lopes and 

Ffolliott 1993) 

This paper reports upon the development of sediment 

rating curves for watersheds in pinyon-juniper woodlands of 

the Interior West. It presents an analysis of suspended 

sediment concentration -streamflow discharge rela tionshi ps 

for two pinyon-juniper watersheds subjected to vegetative 

conversion treatments, and a control watershed that represents untreated conditions. These comparisons provide a 

basis for determining the effects of the conversion treatments on sedimentation processes. Differences between 

snowmelt-runoff and convectional rainfall streamflowgeneration events were also considered. 

Study Area ________ _ 

The watersheds studied are located about 80 km south of 

Flagstaff, Arizona, a tributary of the Verde River, in the 

Colorado Plateau physiographic province. These watersheds, established by the USDA Forest Service to evaluate 

the effects of vegetative conversion treatments on multiple 

use values, supported stands of Utah juniper (Juniperus 

osteosperma) and pinyon (Pinus edulis var. fallax). Descriptions of overstory tree species compositions and density 

conditions have been presented by Clary and others (1974), 

Ffolliott and Thorud (1974), and Baker (1982) and, therefore, will not be presented here. 

The watersheds average 1,600 m in elevation. Springerville 

very stony clay soils derived from basalt and cinder parent 

materials predominate (Williams and Anderson 1967). The 

clays are primarily montmorillonite which swell and shrink 

during each wet and dry cycle (Baker 1984). Infiltration 

rates for this soil series range between 2.0 and 6.4 cmlhr 

(Baker 1982). Stream channels on the watersheds have a 

southwesterly orientation. Annual precipitation average 

450 mm, occurring largely in two seasons. The most important precipitation from a streamflow-generating standpoint 

is that originating from the frontal storms of October 

USDA Forest Service Proceedings RMRS-P-9. 1999 
through April, when about 60 percent ofthe annual precipitation (both rain and snow) falls. A second precipitation 

season is July through early September, when high-intensity, short-duration, localized convectional storms are common. Average winter water yields (22.9 mm) account for 85 

percent of the total annual water yield (Baker 1982). Suspended sediment accounts for 75 to 80 percent of the total 

annual sediment discharge from the watersheds studied. 

Vegetative Conversion 

Treatments __________ _ 

A cabling treatment was applied to a 131-ha watershed 

(WS 1) in 1963. Larger trees were uprooted by a heavy cable 

pulled between two bulldozers. Smaller trees missed by 

cabling were hand-chopped, slash- was burned, and the 

watershed seeded with a mixture of forage species. The 

treatment did not result in significant increases in annual 

water yields. In a second conversion treatment, a mixture of 

picloram (2.8 kg/ha) and 2,4-D (5.6 kg/ha) was applied by 

helicopter to 114 ha of a 147 -ha watershed (WS 3) in 1968. 

The remaining 35 ha were either not treated or the trees 

were sprayed with a backpack mist-blower. The intent of 

this treatment was to reduce transpiration losses by killing 

trees, reduce evaporation losses from the soil by leaving the 

dead trees standing, and reduce the amount of overland 

water flow trapped in the pits created when trees were 

uprooted by cabling (Baker 1984). The herbicide treatment 

resulted in an increase in annual water yields of about 15.5 

mm. The third watershed was a 51-ha control (WS 2) against 

which the cabling and herbicide treatments were evaluated. 

Conditions on this control watershed represented those 

obtained through custodial management, that is, through 

the use of minimal managerial inputs. 

Procedures ____________ _ 

A total of 191 paired suspeilded sediment concentrationstreamflow discharge measurements (in excess of 0.05 m/s) 

obtained from 1975 through 1982 (12 years after the cabling 

treatment in one watershed and 7 years following the herbicide treatment in the other) were used in deriving sediment 

rating curves. Either grab samples or integrated samples 

obtained with a DH-48 were analyzed by filtration to determine suspended sediment concentrations. Streamflow was 

measured in concrete trapezoidal flumes (Baker 1986). When 

a sample of suspended sediment was collected, the time was 

indicated on a digital tape on continuous water-level recorders at the gauging stations. The sediment data used in this 

analysis were collected at time intervals greater than 1 hr to 

avoid the possibility of correlation among the paired data 

sets. 

Two types of events served as the basis for studying the 

effects of streamflow-generation mechanisms on suspended 

sediment concentrations: 

• Type 1. Snowmelt-runoff events not proceeded by precipitation; relatively slow response time to peak 

streamflow discharge; streamflow duration of several 

days or weeks; occurs in late winter-early spring. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

• Type 2. High-intensity, short-duration, mostly convectional rainfall events; rapid response time to peak 

streamflow discharge; streamflow duration of hours or 

a few days; occurs in late summer-early fall. 

Rain-on-snow events, which represented less than 10 percent of the streamflow-generation mechanisms on the watersheds studied, were excluded from the analysis. 

Sediment rating curves most frequently take a power 

function form, such as: 

(1) 

where C = suspended sediment concentration (mglL), Q = 

streamflow discharge (m3/s), and a, b = constants for a 

particular stream. Sediment rating curves to be derived as 

a power function are commonly approximated by leastsquare linear regressions of logarithmic-transformed data 

(Walling 1977). Therefore, this transformation was used to 

develop the sediment rating curves in this study. The coefficient of determination, R2, was used to compare the goodness-of-fit of the sediment rating curves. To correct for the 

dependence of goodness-of-fit on degrees of freedom, an 

adjusted coefficient of determination, Ra2

, was used: 

Ra2 = R2 - [P(l - R2)/(N - P - 1)] (2) 

where N = number of observations, and P = number of 

independent variables = 1. 

Results and Discussion 

A summary of statistics for suspended sediment concentration and streamflow discharge for the three watersheds 

are shown in table 1. Analysis of suspended sediment concentrations began with the complete data sets from each of 

the watersheds studied. These data sets were subsequently 

partitioned into the type of streamflow-generation mechanisms (snowmelt-runoff or convectional rainfall). The "Chow 

test," details of which are presented by Kmenta (1986), was 

performed in this second step to test the null hypothesis that 

the parameters of the curves (a and b) had not changed 

significantly at the 95 percent level of significance. 

Measurements made during periods of high-streamflow 

discharges (Type 2 events) were assigned the same weight as 

meas uremen ts made during low -streamflow discharges (Type 

1 events) in deriving sediment rating curves for each watershed. The parameters "a" and "b" of the relationships are 

presented in table 2 with the 95 percent confidence limits, 

fitted standard errors, coefficients of determination, and F 

statistic. 

There was a difference in the "a" and "b" val ues between 

the sediment rating curve for the cabled watershed (WS 1) 

and that for the untreated control watershed (WS 2) at 

streamflow discharges greater than 0.15 m3/s. This difference indicates that there are higher suspended sediment 

concentrations from the cabled watershed than from the 

control for streamflow discharges greater than 0.15 m3/s. 

These higher concentrations are likely a reflection of the soil 

disturbances caused by uprooting trees in the cabling treatment (Clary and others 1974). However, there was not a 

statistical difference for sediment rating curves derived 

for the watershed treated with herbicides (WS 3), which 

303 
Table 1-Summary of statistics for suspended sediment concentration and streamflow discharge. 

WS1 Sediment Concentration (mg/L) Streamflow (m3

/s) 

Event type2 n4 Mean StDv Min Max Mean StDv Min Max 

ALL 117 8.88 13.33 0.39 73.37 0.102 0.056 0.058 0.261 

104 8.97 13.64 0.38 73.07 0.101 0.056 0.058 0.261 

2 12 5.50 5.38 1.17 15.99 0.104 0.030 0.058 0.127 

2 ALL 32 7.87 6.94 2.10 40.17 0.093 0.035 0.058 0.216 

2 1 21 7.74 8.21 2.10 40.17 0.096 0.030 0.060 0.216 

2 2 10 7.25 2.59 4.29 12.01 0.073 0.011 0.058 0.084 

3 ALL3 42 10.55 13.69 0.74 80.17 0.088 0.028 0.059 0.151 

3 1 41 10.18 13.64 0.74 80.17 0.087 0.027 0.058 0.151 

1WS 1 = cabled watershed, WS 2 = control watershed, and WS 3 = herbicide watershed. 

2ALL = complete data set for each watershed; 1 = snowmelt-runoff events, 2 = convenctional rainfall events. 

3Event type 2 is not represented in the data set for WS 3. 

4Sample (n) for the streamflow-generation mechanisms do not add up to the n for the complete data set for each watershed studied because of the inclusion of 1 frontal 

rainfall event occurring in late-fall in the complete "data sets. 

Table 2-Sediment rating curve parameters with the 95 percent confidence limits, standard errors, coefficients of determination, and F 

statistics. 

2 

2 

2 

3 

3 

Event 

type2 

ALL 

1 

2 

ALL 

1 

2 

ALL3 

1 

n4 

117 

104 

12 

32 

21 

10 

42 

41 

95 Percent 

Confidence 

a limits5 

639.04 421.70 - 968.28 

697.71 448.95 - 1084.17 

356.71 55.41 - 2296.24 

107.26 53.63 - 214.53 

196.01 69.34 - 554.09 

616.84 220.64 - 1724.20 

435.75 135.94 - 1397.76 

344.52 103.53 - 1146.69 

95 Percent 

Confidence Fitted 

b limits5 Error R2 F 

2.10 1.77- 2.44 0.23 0.58 158.32 

2.13 1.77 - 2.48 0.23 0.57 140.17 

1.98 0.54 - 3.43 0.29 0.43 9.42 

1.17 0.58 - 1.76 0.18 0.33 16.36 

1.48 0.63 - 2.34 0.22 0.38 13.15 

1.71 0.63 - 2.79 0.05 0.58 13.41 

1.74 0.70 - 2.27 0.38 0.21 11.58 

1.65 0.57 - 2.72 0.39 0.18 9.59 

1WS 1 = cabled watershed, WS 2 = control watershed, and WS 3 = herbicide watershed. 

2ALL = complete data set for each watershed; 1 = snowmelt-runoff events, 2 = convenctional rainfall events. 

3Event type 2 is not represented in the data set for WS 3. 

4Sample (n) for the streamflow-generation mechanisms do not add up to the n for the complete data set for each watershed studied because of the inclusion of 1 frontal 

rainfall event occurring in late-fall in the complete data sets. 

5Confidence limits have been retranstormed to original units for interpretation. 

experienced little soil disturbances as a result oftreatment, 

and the untreated watersheds. 

Sediment rating curves were developed to represent suspended sediment responses to the type of streamflow-generation mechanisms. There were no consistent differences in 

sediment rating curves when the data sets used to derived 

the equations were partitioned according to streamflowgeneration mechanisms. This finding differs from that reported for a higher-elevation ponderosa pine (Pinus ponderosa) watershed on Beaver Creek, where a significant increase 

in suspended sediment concentration occurred due to 

streamflow-generation mechanisms (Lopes and Ffolliott 

1993, Dong 1996). 

Management Implications 

There was a significant difference in the suspended sediment concentrations when the cabled and control watersheds are compared. Soil disturbance caused by the uprooting of trees on WS 1 is the likely reason for this change. 

304 

Earlier studies on Beaver Creek had indicated that uprooting oftrees by cabling can increase the potential for soil loss 

by overland water flow (Skau 1960, 1961). Sedimentation 

parameters can also change, in general, because ofincreased 

streamflows, although this did not occur after this cabling 

treatment (Clary and others 1974). The difference in results 

can be attributed to the fact that finer sediments (silt and 

clay) require less energy to remain in suspension and, as a 

consequence, can be transported by smaller water flows 

than would be needed to more larger particles. 

This result, and those of Clary and others (1974) and 

Baker (1982), are different than might be expected from the 

hypothesis that removal of overstory trees to increase production of the herbaceous plants forming a protective cover 

will cause less soil erosion. No changes in suspended sediment concentration occurred on WS 3 when herbicides were 

applied in a conversion treatment. The soil surface on this 

watershed was not disturbed by the treatment, since most of 

the herbicide was applied by helicopter. 

Large-scale vegetative conversions of pinyon -juniper woodlands have been less frequent in the Interior West than in 

USDA Forest Service Proceedings RMRS-P-9. 1999 
recent years, due largely to the increased environmental 

concerns and the increasing emphasis being placed on more 

holistic management ofthe pinyon -j uniper ecosystems (Shaw 

and others 1995). Little changes in suspended sediment 

concentration because of conversion treatments, therefore, 

are likely to occur in the near future. 

Conclusions --------------------------------- Sediment rating curves have been developed for three 

pinyon-juniper watersheds in northern Arizona that had 

been subjected to treatments ranging from custodial management to vegetative conversions by cabling and application of herbicides. The cabling treatment resulted in increased suspended sediments at specified streamflow 

discharges because of the soil disturbances caused by the 

uprooting of trees, while the herbicide treatment did not 

result in a change. This finding differs from previous studies 

(Clary and others 1974, Baker 1982), and could be helpful to 

managers in responding to questions about the impacts of 

vegetative manipulation on sediment concentrations from 

pinyon-juniper woodlands with similar soils and precipitation regimes throughout the Interior West. 

References ----------------------------------- Baker, M. B., Jr. 1982. Hydrologic regimes offorested areas in the 

Beaver Creek watershed. Gen. Tech. Rep. RM-90. Fort Collins, 

CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 

Baker, M. B., Jr. 1984. Changes in streamflow in a herbicide-treated 

pinyon-juniper watershed in Arizona. Water Resources Research. 

20:1639-1642. 

Baker, M. B., Jr. 1986. A supercritical flume for measuring sediment-laden streamflow. Water Resources Bulletin. 20:847-851. 

Brooks, K. N.; Ffolliott, P. F.; Gregersen, H. M.; DeBano, L. F. 1997. 

Hydrology and the management of watersheds. Ames, IA: Iowa 

State University Press. 

Clary, W. P.; Baker, M. B., Jr.; O'Connell, P. F.; Johnsen, T. N., Jr.; 

Campbell, R. F. 1974. Effects of pinyon-juniper removal on 

natural resource products and uses. Res. Pap. RM-128. Fort 

Collins, CO: U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Forest and Range Experiment Station. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Dong, C. 1996. Effects of vegetative manipulations on sediment 

concentrations in north-central Arizona. MS Thesis. Tucson, AZ: 

University of Arizona. 

Ffolliott, P. F.; Thorud, D. B. 1977. Water yield improvement by 

vegetation management. Water Resources Bulletin. 13:563-571. 

Gifford, G. F. 1975. Approximate annual water budgets of two 

chained pinyon-juniper sites. Journal of Range Management. 

28:73-74. 

Gottfried, G. J.; Swetnam, T. W.; Allen, C. D.; Betancourt, J. L.; 

Chung-MacCoubrey, A. L. 1995. Pinyon-juniper woodlands. In: 

Finch, D. M.; Trainer, J. A, tech. coords. Ecology, diversity, and 

sustainability of the middle Rio Grande Basin. Gen. Tech. Rep. 

RM-268. Fort Collins, AZ: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment Station. 

95-132. 

Kmenta, J. 1986. Elements of econometrics. New York, NY: 

Macmillian Publishing Company. 

Lopes, V.L.; Ffolliott, P. F. 1993. Sediment rating curves for a 

clearcut ponderosa pine watershed in northern Arizona. Water 

Resources Bulletin. 29:369-382. 

Lopes, V. L.; Ffolliott, P. F.; Gottfried, G. J.; Baker, M. B., Jr. 1996. 

Sediment rating curves for pinyon juniper watersheds in northern Arizona. Hydrology and Water Resources in Arizona and the 

Southwest. 26:29-33. 

Shaw, D. W.; Aldon, E. F.; LoSapio, C., tech. coords. 1995. Desired 

future conditions for pinon-juniper ecosystems: Proceedings of 

the symposium. Gen. Tech. Rep. RM-258. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station. 

Skau, C. M. 1960. Some hydrologic characteristics in the Utah 

juniper type of northern Arizona. PhD Dissertation. East Lansing, MI: Michigan State University. 

Skau, C. M. 1961. Some hydrologic influences of cabling juniper. 

Res. Note 62. Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range Experiment 

Station. 

Walling, D. E. 1977. Assessing the accuracy of suspended sediment 

rating curves for a small basin. Water Resources Research. 

13:531-538. 

Wilcox, B. P. 1994. Runoff and erosion in intercanopy zones of 

pinyon-juniper woodlands. Journal of Range Management. 47: 

285-295. 

Williams, J. A; Anderson, T. C. 1967. Soil survey on Beaver Creek 

area, Arizona. Washington, DC: U.S. Department of Agriculture, 

Forest Service and Soil Conservation Service, in cooperation with 

the Arizona Agricultural Experiment Station. 

Wright, H. A; Churchill, F. M.; Stevens, W. C. 1976. Effects of 

prescribed burning on sediment, water yield, and water quality 

from dozed juniper lands in Texas. Journal of Range Management. 29:294-298. 

305 
The Panguitch Wildlife Habitat Improvement 

Project 

Harry Barber 

Paul Chapman 

Abstract-The purpose of this project was to remove a significant 

amount of pinyon-juniper trees and establish an understory more 

conducive to big game. Tree removal was accomplished using prison 

crews and hand tools. Crews removed trees in a mosaic pattern 

leaving groups of trees standing together to allow for better movement of big game and a more natural appearance. Fire and chaining 

were not options during the period of time the trees were removed. 

By use of the prison crews the Bureau of Land Management was able 

to open up an encroaching stand of trees allowing native grasses and 

shrubs to flourish. 

The pinyon-juniper vegetation type is found in the Intermountain Region mostly at intermediate elevations in 

areas that receive less than twenty inches of precipitation 

annually (Vallentine 1980). 

In the Kanab Resource Area (KRA) there are a number of 

areas that appear to be filling in with both pinyon and 

juniper trees. It is evident that as the trees encroach into 

shrub or grass/forb sites production is reduced in these 

areas. As these areas fill in with pinyon-juniper trees they 

become less productive and decrease available forage to big 

game species. 

In 1997 the Bureau of Land Management, Kanab Resource Area (KRA) and the Division of Wildlife Resources, 

Southern Region (DWR) formed a cooperative agreement. In 

the agreement it was determined that prison crews would 

be hired to hand-cut encroaching trees in the more desired 

sagebrush parks adjacent to dense stands of mostly pinyonjuniper trees. The project was 'carried out near Panguitch, 

UT. on public lands administered by the KRA. It was the 

opinion of those involved that the more dense stands of 

trees located along the rocky ridges probably represented a 

more climax situation and should not be disturbed. Burkhardt 

and others (1969), determined in their work that juniper 

was climax only on rocky ridges and rimrock where soil 

development was limited. 

Prison crews worked on the project for several weeks using 

chain saws to cut the trees down. Some parameters were 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedin~s: 

ecology and management of pinyon-juniper communities within the Intenor 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogd.en, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountam Research 

Station. 

Harry Barber is Wildlife Biologist, Bureau of Land Management, Kanab 

Resource Area, Kanab, UT. 84741. Paul Chapman is Botanist, Bureau of 

Land Management, Kanab Resource Area, 84741. 

306 

provided the crews in terms of what trees should be cut and 

what trees should remain standing. Under no circumstances 

were the crews to cut ponderosa pine (Pinus ponderosa). 

Crews were instructed to cut the younger pinyon and 

juniper trees. The younger trees «10 ft) appeared to be most 

responsible for the encroachment into the more open areas. 

Crews were also instructed to leave patches of trees standing at random locations within the areas they were cutting 

in. It was determined that these patches would allow animals greater protection as they moved through the area. 

Peek (1986), demonstrated that where large clearcuts may 

be beneficial to livestock, smaller cuts are more important to 

big game species. Tree removal in some KRA projects was 

carried out on a larger scale than was done by the prison 

crews. When large areas were cleared of trees the areas 

usually had to be seeded. Success of these seedings was 

highly dependent on time of year, moisture. Seeding costs for 

native seed are fairly high. By cutting the younger, smaller 

trees that were encroaching into preferred big game sites no 

seeding was necessary. Native grasses and shrubs were 

present in numbers sufficient to provide seed in areas where 

trees were removed. Indian Ricegrass (Stipa hymenoides) 

and needle-and-thread grass (Stipa comata) were the two 

dominant grasses in the area where trees were removed. 

Since this work was accomplished in the Fall of 1997 no 

conclusions as to the success of the project can be made at 

this time. Vegetative and wildlife transects are being placed 

in the areas where trees were removed to determine if 

work ofthis kind should be carried out in the future. Several 

photo plots have also been established. It is expected that 

native grasses and shrubs will better maintain themselves 

without the competition of encroaching pinyon and juniper 

trees. It is likely that the BLM and DWR will do more work 

of this nature with prison crews in 1998. 

It is important to note that managers were able to be 

highly selective in determining what trees should be cut and 

how the shape of the cuts should be made by using prison 

crews. It was learned that if the crews are experienced and 

have some knowledge of big game foraging habits with little 

instruction the crews could create openings in the trees in a 

mosaic pattern. 

References __________________ __ 

Burkhardt, J. Wayne; Tisdale, E. W. 1969. Nature and successional 

status of western juniper vegetation in Idaho. J. Range Mgt. 

22(4):264-270. 

Peek, James M. 1986. A review of wildlife management. Englewood 

Cliffs, NJ: Prentice-Hall Publishing. 486 p. 

Vallentine John F. 1980. Range developments and improvements, 

second ~d. Provo, UT: Brigham Young University Press. 545 p. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Watershed Restoration Through Integrated 

Resource Management on Public and 

Private Rangelands 

Sid Goodloe 

Abstract-Until recently much of the rangeland in the Western 

United States was in a serious downward trend. Water quality and 

quantity was declining as the result of the continuous livestock 

grazing practices employed at the turn of the century followed by 

80 years of fire suppression. Thirty-five years ofintegratedlholistic 

resource management at the Carrizo Valley Ranch has reversed 

this trend. In addition to restoration of rangeland productivity, 

the riparian area on the ranch has been restored, wildlife populations enhanced, and perennial streamflow restored. The practical 

experience gained at the ranch should be useful to private landowners, public land managers, and water quality agencies throughout the brittle ecosystems of the Southwestern United States. 

Some ofthe techniques perfected at Carrizo Valley Ranch are being 

demonstrated on an adjacent watershed in the Smokey Bear 

Ranger District of the Lincoln National Forest. 

The shortgrass rangelands found in the Western United 

States are generally harsh ecosystems. Careful management of these areas is essential if they are to maintain 

sustained prod uction or recover from past land management mistakes (Stoddart and others 1975). Many watersheds in the West contribute massive loads of sediment 

washed from the land surface or scoured from eroding 

gullies and streambanks to the streams and rivers that 

drain them. The New Mexico Environment Department 

reports that 95 percent of the State's surface water is 

impacted by nonpoint source' pollution (NMED 1990) and 

that turbidity is one of the major causes of use impairment 

in these waters (NMED 1988). Reports by early surveyors, 

naturalists, and trappers detail the abundance of grass 

and clear clean water found on these same watersheds 

(Leopold 1933/1991), a sharp contrast to the conditions 

seen today. 

Many factors have contributed to the drastil' changes 

that can be seen in the rangeland watersheds of the Western 

United States, but most range management professionals 

agree that the heavy stocking rates and the continuous 

grazing practiced by stockmen at the end of the 1800's 

followed by increasingly efficient fire suppression are the 

leading causes of these changes. H. 1. Bently and E. O. 

Wooten, early agricultural agents in Texas and New Mexico, 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Sid Goodloe is Owner/Operator, Carrizo Valley Ranch, Box 598, Capitan, 

NM 88316. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

described the situation: "In a short time every acre of grass 

was stocked beyond its fullest capacity .... The grasses were 

entirely consumed; their very roots were trampled into the 

dust and destroyed" (Bently 1898). "The stockman could not 

protect the range from himself, because any improvement of 

his range was only an inducement for someone else to bring 

stock in upon it; so he put the extra stock on himself" 

(Wooten 1908). As a result, native grasses were replaced by 

sagebrush, mesquite, juniper, and other invading brush 

species that were less suited for holding soil in place 

(Chaney and others 1990) and that were more efficient at 

water extraction (Stoddart and others 1975). Topsoil, which 

requires thousands of years to develop in harsh ecosystems 

(Brady 1974), washed away; gullies formed from unchecked, 

concentrated runoff; streambanks eroded and downcut; 

water tables lowered; and perennial streams became intermittent or dry (Chaney and others 1990; Platts 1990). 

The ability of the land to recover from these effects has 

been greatly reduced because the entire ecosystem had been 

so radically altered. The harshness of the environment 

contributes to the difficulty in reestablishing the climax or 

the highest ecological condition of the range. As a result, 

simple manipulation of a single range management factor, 

such as reducing livestock numbers, is not sufficient to 

result in significant environmental improvement (DeBano 

and Schmidt 1989). These systems will take many years to 

recover by themselves. Direct actions aimed at total watershed rehabilitation and applied in a holistic and integrated 

system are necessary to ensure the restoration of Western 

watersheds and associated natural resources of water, timber, grass, wildlife, and fisheries (Platts 1990). This type of 

integrated or holistic resource management has been successfully demonstrated on the Carrizo Valley Ranch. 

Integrated Resource Management 

on Private Lands -------------------------

There are many definitions of IntegratedIHolistic Resource Management (IRM), but I like to define it as the 

integration of all components, economic, human and environmental into a synergistic, comprehensive plan that allows management for long-term sustainability rather than 

short-term production. This type of management is essential for protecting valuable natural resources found in our 

Western watersheds and is also an essential management 

tool for protecting the entire planet. Considering the unlimited supply of examples of bad natural resource management in every U.S. State and in every country in the world, 

it is clear that we are now charged with the responsibility of 

not only managing the resources under our jurisdiction in 

307 
an integrated manner, but we must also inform politicians 

and populations everywhere that we are no longer in the 

pioneering/unplanned development mode. We have reached 

the point that resource interrelationships must be recognized and development planned accordingly. Pressing 

needs of growing populations must be met but not at the 

expense of the ecosystems's ustainabili ty. 

Initial Actions ________ _ 

My ranch is in the South Central Mountains of New 

Mexico at about 7,000 ft elevation. Average annual precipitation is about 46 cm (18 inches), halfofwhich falls as snow. 

The soils range from gravelly hillsides to clay and clay loam 

bottoms. Watercourses on the ranch were actively eroded 

and brush infestation flourishing when I purchased the 

property. My most demanding problem was the homogeneous vegetative composition and low herbage production. 

The major grass found was an almost pure, tightly packed 

turf of blue grama that grew very little because of its sodbound condition. A major portion of the ranch had scattered 

to thick stands of pinyon-juniper that were even-aged populations. Areas between the trees as well as directly under 

the canopy were bare and subject to erosion. 

I began to study the origination of this eroded, brushinfested condition. I realized that year-long grazing and 

brush infestation were severely limiting herbage production. My initial strategies were (1) to divide the ranch into 

summer and winter pastures so I could at least reserve some 

winter grazing and (2) to begin a systematic brush control 

program. Although these changes were beneficial, it was not 

until I spent time in Rhodesia (Zimbabwe) in 1964 that I 

experienced firsthand and began to understand the principles of Short Duration Grazing in action, and the dynamics of an open savanna ecosystem. I recorded my 

findings in a paper published in the November 1969 issue 

of the Journal of Range Management, returned to my 

ranch, and after some very low budget fencing, put these 

principles into practice. . 

Rotational Grazing System 

I divided large paddocks into much smaller ones using 

posts cut on the ranch to support a three-wire suspension 

fence. Paddock division was planned according to topography, existing fences, and available water, not in the wagon 

wheel or grazing cell pattern often advocated. Once the 

rotation had become established, the cattle practically 

moved themselves, anticipating paddock changes. I found 

that graze and rest periods could be adjusted to fit the 

current precipitation and season of use. I also found that as 

the vegetative growth rate increases, so should the frequency of rotation and that rotation during the dormant 

season was not necessary. My initial goal now became "to 

produce the maximum pounds of marketable beef per hectare while improving range condition." This naive but commendable goal was economically impractical in a period of 

low beef prices, so I needed to find other profitable uses of 

available resources. 

308 

Additional Income Source 

Fee hunting of deer and turkey became a significant 

income producer immediately after I built a cabin to facilitate game harvest. As a result, improved wildlife habitat 

and overall aesthetic quality became my secondary goal. 

Return to Climax Condition as the 

Primary Goal 

The pieces of the puzzle then began to fall into 

place. I realized that if fish and beaver appeared on the 

600 year old Indian Petroglyphs on my place, there certainly must have been running streams w here I now found 

only arroyos with steep banks and dry rocky bottoms. I 

researched 100 year old surveyors notes that described the 

terrain as an open savanna rather than an almost solid 

canopy of invading brush species. I realized that the invading brush, made possible by year-long grazing and 80 years 

of total fire suppression, was not only removing most of 

the moisture from the soil, but was also shutting down 

herbage growth, thereby causing sheet and gully erosion. I 

recognized that although I had previously discounted a 

return to climax or near climax condition, I might be able to 

make economic sense out of that approach if it became my 

primary goal. I visualized the open savanna as it was over 

100 years ago, with mixed conifers on the north slopes and 

the highly productive riparian areas that made up the 

mosaic of the Carrizo Valley. 

Brush Management and Watershed 

Stabilization _________ _ 

I then began to implement a cautious return to climax in 

a manner that was economically justifiable in my situation. 

Mechanical removal of invading pinyon-juniper in an area 

that requires 10 to 15 ha per animal unit could not be 

justified because costs were higher than land values. However, some mechanical brush control in the better soil types 

was required as was erosion control (that is, reseeding, 

pushing invading brush into active gullies, and building 

water retention dams). It was necessary to finance this 

using other available resources. 

Selective thinning of young invaders, followed by prescribed burning and reseeding with native grass species, 

became the major thrust of the plan to return to a climax 

ecosystem. The by-products: fence posts, fuel wood, vigas, 

trees for landscaping, and Christmas trees financed the 

plan. Another beneficial by-product was the increase in 

mule deer population, not only because of habitat improvement, but because ponderosa pine vigas must be cut and 

peeled during the win ter months. This provided an adequate 

supply of green browse (tree tops) throughout the winter, 

resulting in a significant (30 to 50 percent) increase in 

the fawn crop. The open savanna created contained 500 to 

800 year old juniper trees, scattered ponderosa pines, and is 

carpeted with a mix of warm and cool season grasses and 

forbs. I have found that because deer and turkey evolved 

USDA Forest Service Proceedings RMRS-P-9. 1999 
under this type of ecosystem, they seem to prefer it to the 

contiguous brush-infested public land. This is what I call 

an "eco-recreation benefit." These factors sharply increased 

income from hunting and paid for more of the necessary 

mechanical rehabilitation work. 

Role of Fire 

The long sought-after open savanna is now well established in the Carrizo Valley, but it must be maintained 

with periodic fire as it was in the climax. Tree ring research 

in New Mexico indicates that most forest areas burned, on 

the average, at 7 to 10 year intervals (Stoddart and others 

1975) before fire suppression began. The key to the successful maintenance burn is the fuel load (as well as the climatic 

conditions of course). There must- be enough herbaceous 

material to carry a fire that is hot enough to kill brush but 

cool enough not to damage the beneficial species. The 

damaging fires in Yellowstone a few years ago demonstrated that the no-burn policy, which originated in the 

ecologically different European forests, was an incorrect 

choice for Western watersheds. Now after many years of 

fire suppression, similar fuel loading is evident throughout 

the Western United States and has made the initial prescribed burn risky. 

Livestock Suited to Their 

Environment 

The pivotal economic component of my operation is the 

production of weaner calves, both for breeding and beef. 

Low-input, sustained production is my goal and is achieved 

by using an animal that is fine-tuned to the environment 

and produces a desirable, marketable product. The hostile 

factors in our environment are snow, cold, wind, and dry 

weather. A cow that can produce under these conditions 

must be, first of all, fertile in t~lat environment. She should 

be black so that wind and snow will not cause or aggravate 

pink eye and cancer eye. Black, of course, absorbs as much 

sparse winter sunlight as is possible and black udders do not 

blister in spring snowstorms. The animal that fulfills all 

these requirements is a composite breed that I have developed through 20 years of selective breeding, called the 

Alpine Black-three-quarters Angus and one-quarter beeftype Brown Swiss. Just as the Zebu composites fit the Gulf 

Coast and southern deserts, the Alpine Black fits the western mountains of Northern America. 

Tangible Benefits ______ _ 

The road back to climax has revealed many changes in 30 

years. Water sources that were dry now have permanent 

running water and lush riparian areas. Grass production 

has increased dramatically and provided more carrying 

capacity. Alpine Black cattle are in sync with their environment and their habitat has improved as well. Recreation 

potential is greatly enhanced due to a more pleasing aesthetic atmosphere and larger wildlife population. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Applicability of Study Results to 

Western Watersheds -------------------- The pinyon-juniper complex comprises more than 63 million acres ofthe rangeland in the Southwest. This ecotype is 

a critical component of the arid region. Pinyon and juniper 

generally form the intermediary boundary between the 

flatter grassland type climax community found on the 

lower slopes and the conifer forest climax community of the 

mountain tops. Considerable debate regarding the density 

of the pinyon-juniper canopy in climax conditions has hindered some watershed restoration efforts. Most range 

conservationists agree, however, that much of the pinyonjuniper found on the lower slopes has escaped its original 

range and modified some of the original savanna type 

ecosystem to a more woodland type. Originally the pinyonjuniper occupied a discrete ecotone in many watersheds, 

but lack of fire and overuse by livestock have left these 

once stable areas in poor condition. Many, however, have a 

high potential for range improvement and revegetation. In 

areas where the pinyon-juniper complex is in especially poor 

condition, range improvement can substantially reduce the 

erosion and sedimentation originating from these degraded 

areas (Stoddart and others 1975). Some ofthe most informed 

members of the environmental community support restoration of Western watersheds but question the removal of 

pinyon and juniper vegetation from those areas where the 

species are in the climax community. As opposed to brush 

removal and range reseeding on areas historically known or 

reasoned to be grassland, brush removal on certain areas 

can have the potential to increase sedimentation and erosion rather than decrease it. Information gained from the 

Carrizo Valley Ranch can be useful to managers needing to 

determine if brush management efforts can be reasonably 

and safely completed and a sustainable system established. 

Riparian areas and the water they surround are of special 

consequence in arid ecosystems. These areas constitute only 

about 2 percent of the total Western acreage, yet they are 

among the most productive and valuable lands. DeBano and 

Schmidt (1989) have described the relationship of upland 

watershed condition to riparian condition and found, not 

surprisingly, a direct correlation between degraded upland 

watershed condition and degraded riparian area condition. 

They concluded that adequate treatment of all critical areas 

in the upper watershed is necessary to provide a stable and 

sustainable riparian area and is critical when attempting 

any riparian restoration project. On Carrizo Valley Ranch, 

we completed most ofthe upper watershed work (stabilizing 

gullies, removing invading brush, and revegetating bare 

ground) before being able to maintain a stable riparian area. 

Chaney and his coworkers (1990) and Platts (1990) found 

that maintenance of riparian areas, once restored, requires 

a different grazing strategy than upland sites. Although I 

have done some riparian corridor fencing, which works to 

protect the riparian area from livestock access, I have 

demonstrated that as long as the principle-limited and 

managed access-is applied, fencing is not always a required 

component. The key to the effective riparian protection 

demonstrated at Carrizo Valley Ranch is protection during 

the growing season if possible and rapid rotation when not. 

309 
Carrizo Demonstration Area __ _ 

The watershed above the Carrizo Valley Ranch is part of 

the Smokey Bear Ranger District of the Lincoln National 

Forest. In 1989 the USDA Forest Service began a watershed restoration and demonstration project on 55,000 acres 

of National Forest of the pinyon-juniper ecosystem. The 

project area contains large expanses of continuous canopy 

pinyon-juniper that, prior to the introduction oflivestock 

in the 1800's and subsequent fire suppression, supported a 

wide variety of native grass plants. As the range degraded, 

trees out-competed grass for available moisture, and soon 

much of the productive soil beneath these dense woodland 

stands eroded away leaving behind an extensive and active 

gully system that continues to transport silt-laden water 

into streams and rivers (Edwards 1991). With the urging of 

private land owners that for years had to contend with the 

deposition of millions of tons of sediment that originated on 

National Forest land, and who had demonstrated that 

watershed rehabilitation was not possible on their private 

landholdings, a unique, cooperative watershed-based project 

was begun. The project focuses on soil stabilization practices, vegetation management, water resource development, 

vehicular travel management, and sound grazing management practices. The project's goals include control of soil 

erosion, stabilization of steep gully slopes, restoration of 

permanent riparian vegetation, and the rehabilitation of 

native rangelands to support a sustainable mix of native 

grass and woody plants. 

As the result of treatments, begun in 1989, cool season 

native species of grass and forbs long absent from the 

National Forest have returned; in several drainages 

springs have begun to flow again, and a wide variety of 

upland and riparian wildlife species have returned to the 

area making use ofthe increased edge areas, water supplies, 

and additional food sources. On private lands adjacent to 

the Forest, benefits have also been reported. In one area, 

4,800 cubic yards of sediment from gully and sheet erosion 

originating on National Forest land was cleaned out of a 

pond. The following spring, after implementation of watershed restoration treatments on the Forest, a spring that had 

not run for 50 years began to flow and continued to flow 

throughout the summer, filling the pond with clear water. 

The pond has now been stocked with trout and catfish. 

310 

Summary 

Integrated resource management is the professional 

vernacular describing what managers do who are in tune 

with efficient, sustained use of the resources that are their 

responsibility. Ifthe use of one resource affects the health or 

production of another adversely, than the whole is diminished and economic and environmental costs are guaranteed to surface somewhere sometime. Common sense and 

vision provide the foundation for bringing all parts of the 

whole together into a comprehensive management plan. 

Interestingly enough, as are many things in life, it is elusive 

because it is so simple. And yet, if we intend long-term 

survival we must implement this approach in every phase of 

natural resource management. 

As watershed restoration and rehabilitation work continues, it is important to understand that there will never be 

sufficient government resources to treat every problem in 

every area. Thus, success lies in demonstrating techniques 

such as those developed on Carrizo Valley Ranch, which 

proved internal and self-sustaining motivation for adoption on both private and public lands. 

References _________ _ 

Bently, H. L. 1898. Grasses and forage plants of Central Texas. 

Bulletin No. 10. USDA Special Agent in Charge of Grass Experiments, Abilene, TX. 

Chaney, E.; Elmore, W.; Platts, W. S. 1990. Livestock grazing on 

Western riparian areas. U.S. Environmental Protection Agency, 

Denver, CO. 

DeBano, L. D.; Schmidt, L. J. 1989. Improving Southwestern 

riparian areas through watershed management. USDA Forest 

Service General Technical Report RM-182, Rocky Mountain 

Forest and Range Experiment Station, Fort Collins, CO. 

Edwards, R. 1991. Carrizo Demonstration Area. United States 

Department of Agriculture, Forest Service. Lincoln National 

Forest, Smokey Bear Ranger District. 

Goodloe, Sid. 1990. Twenty years of integratedlholistic resource 

management, from integrated resource management symposium, Morelia, Mexico, March 27, 1990. 

Leopold, Aldo. 1933/1991. The virgin Southwest, reprinted in The 

River of the Mother of God and other essays by aldo Leopold. 

Flander, S.; Barid, J., eds. University of Wisconsin Press. 1991. 

New Mexico Environment Department. 1990. Biennial Water 

Quality Report. NMED, Santa Fe, NM. 

Platts, W. S. 1990. Managing fisheries and wildlife on rangelands 

grazed by livestock. Nevada Department of Wildlife. 

Stoddart, L. A.; Smith, A. D.; Box, T. W. 1975. Range management, 

third edition. McGraw Hill Book Co., St. Louis, MO. 

Wooten, E. O. 1908. The range problem in New Mexico. Bulletin 10. 

Agri. Expt. Station, New Mexico College of Ag. and Mech. Arts. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Initial Response of Soil and Understory 

Vegetation to a Simulated Fuelwood Cut of 

a Pinyon-Juniper Woodland in the Santa Fe 

National Forest 

Samuel R. Loftin 

Abstract-The Santa Fe National Forest, Espanola Ranger District, the Bandelier National Monument, and the Rocky Mountain 

Research Station are evaluating a treatment designed to stabilize 

the soils and increase the abundance- of herbaceous plants in 

degraded pinyon-juniper ecosystems. The treatment removed all 

pinyon less than 8 inches in diameter and all juniper. The trees 

were felled, lopped, and the wood and limbs (slash) were scattered 

across the site. Cover of herbaceous vegetation nearly doubled on 

the treated site after one growing season and more than doubled 

after two growing seasons. Significantly higher plant species richness was recorded on the treated site. The preliminary results 

indicate that this could be an effective pretreatment to the reintroduction of fire. 

Many grasslands in the western United States are dependent upon periodic fire to maintain their productivity and 

stability (Clements 1936). The absence of fire could lead to 

the succession of grasslands to woodlands or desertscrub 

(Dick-Peddie 1993). Throughout the western United States, 

a combination of widespread livestock grazing and periodic 

drought has promoted woody plant expansion and dominance in areas believed to have been predominantly grassland (Burkhardt and Tisdale 1976; Buckman and Wolters 

1986; Grover and Musick 1990; Miller and others 1994). 

Livestock can reduce fine fuel loads and alter fire frequencies or eliminate fire completely. Periodic drought can select 

for deep-rooted woody species over shallow-rooted grasses 

and forbs (Schlesinger and others 1990). 

Regardless of the extent of grasslands that have been 

replaced by pinyon-juniper or juniper woodlands, the type 

conversion of grassland to woodlands is not necessarily 

considered to be a problem. The expansion and contraction 

of woodland and grassland boundaries is a natural process 

that has been occurring across this landscape for thousands 

of years (Betancourt 1986; Jameson 1986; Miller and Wigand 

1994; Van Devender and others 1984). The problem, as 

commonly perceived, is the increase in surface runoff and 

soil erosion that often accompanies a loss of herbaceous 

plant cover. Surface runoff and soil erosion remove the two 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Samuel R. Loftin is a Research Plant Ecologist, Rocky Mountain Research 

Station, 2205 Columbia, SE, Albuquerque, NM 87106. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

resources necessary for maintaining the stability and productivity of these ecosystems, water and soil. Once the soil 

is gone, the system cannot support a grassland and the 

question of whether grasslands or woodlands belong on the 

site becomes academic. 

Objectives 

The objectives ofthis research are to evaluate methods for 

restoring properly functioning eda phic and hydrologic processes, which preserve our options for future land management. More specifically, we hope to stabilize the soil, increase water availability, and increase herbaceous plant 

abundance, which should further stabilize the soil. This 

should initiate a positive-feedback cycle of increasing stability and productivity and disrupt the present cycle of increasing degradation. We plan to re-introduce fire back into 

this system, initially as a restoration treatment to control 

tree seedlings. Ultimately, fire must be used as a management tool to maintain the structure and function of the 

grassland component of this ecosystem. 

Approach 

The thinning treatment should affect several processes 

that could lead to increased soil stability, plant water availability, and herbaceous plant abundance. Removing trees 

will result in a reduction in competition for water between 

trees and herbaceous plants. The slash mulch should increase soil surface roughness and reduce runoff, thereby 

increasing infiltration and water availability. The mulch 

will shade the soil and reduce air flow, thereby reducing 

evaporative loss. The mulch will reduce raindrop impact on 

bare soils which will reduce the potential for erosion. The 

mulch will insulate bare soils in the winter, thereby inhibiting frost heave which loosens the soil and also damages 

seedling plants. Finally, the slash mulch will inhibit grazing 

by large ungulates that prefer not to nose around in the 

piles of sticks and twigs. 

The trees were cut with chain saws, rather than chaining, 

cabling, or pushing which requires the use of heavy equipment. This method reduces the disturbance associated with 

the treatment and reduces the potential for soil erosion and 

establishment of invasive weeds. This treatment can be 

implemented as a fuelwood sale which would reduce labor 

costs for the management agency and provide a resource for 

the public. This type of fine-scale management also allows 

managers to tailor the treatment to the desired future 

condition for the site. 

311 
Methods _________ _ 

Site Description 

The study site is located in northcentral New Mexico, on 

the Santa Fe National Forest, Espanola Ranger District. 

The site is approximately 25 ha on a south-facing slope 

which, previous to treatment, supported a dense stand of 

pinyon (Pinus edulis) and juniper (Juniperus monosperma) 

trees. Dominant herbaceous plant species incl ude blue grama 

(Bouteloua gracilis), mountain muhly (Muhlenbergia 

montana), muttongrass (Poa fendleriana), tarragon (Artemisia dracunculus), and pinque (Hymenoxys richardsonii). 

Soils on the site are classified as fine-loamy to loamyskeletal, mixed mesic Typic Haplustalf (USDA 1993). 

Treatment 

The treatment used in this study was removal of all 

pinyon less than 8" diameter at breast height, and all 

juniper. Trees were cut at ground level, limbed and lopped. 

The slash was distributed evenly across the surface of the 

site. The treatment was conducted in April, 1995 by personnel from the Espanola Ranger District. 

Experimental Design 

There was no replication of treatments in this experimental design. Each treatment (thinned and control) was 

approximately 10-15 ha. The treatments were positioned 

end to end along a south-facing slope. Each treatment was 

divided into five blocks. Within each block there are three, 

100 m transects, one for vegetation sampling, one for soil 

sampling, and one for soil erosion estimates. Only the 

vegetation analysis will be discussed in this paper. 

The vegetation was sampled using the Community Structure Analysis (CSA) technique of Pase (1981). This sampling techniq ue generates estima tes of cover, frequency, and 

density for sampled plant species. Only cover estimates will 

be presented in this paper. Estimates of species richness 

(number of species) can be extracted from the CSA data. 

Vegetation was sampled in Fall 1994 (pretreatment), Fall 

1995 (one growing season post-treatment) and Fall 1996 

(two growing seasons post-treatment). 

Statistical Analysis 

Due to the lack of treatment replication, this study must 

be considered a case study, the results of which are not to be 

extrapolated beyond the spatial and temporal limits of the 

data collected. The effect of thinning was tested by comparing post-treatment conditions on the treated plots to any 

change on the control plots for comparable time periods. A 

repeated measures analysis was utilized with thinned vs. 

control included as a treatment factor, post-treatment 

years as repeated measures, and the pre-treatment year 

(1994) as a covariate. In some instances, the effect of thinning was not the same for both post-treatment years (that is, 

significant interaction between treatment and time). In 

these instances, significance ofthinning for individ ual years 

was assessed by applying a t-test to the change from pretreatment conditions for each treatment for a particular year. 

Similarly, significance of potential time trends was assessed 

by applying a t-test to the change from pre-treatment conditions for each post-treatment year within a particular treatment category. Type I error for these sets of t-tests was 

maintained by applying a Bonferroni adjustment to significance levels of individual tests (Miller 1981). All statistical 

analyses were conducted using the Statistical Software 

for the Social Sciences (SPSS Inc. 1990). 

Results ___________ _ 

Analysis of cover shows significant treatment effects on 

all cover types (table 1). Tree cover and bare soil both 

decreased as a direct result of the thinning treatment and 

there was no significant (P::; 0.05) difference between posttreatment years. Total herbaceous cover was significantly 

greater on the thinned area and increased significantly 

from Fall 1995 to Fall 1996. Forb cover and grass cover 

Table 1-Cover (%) means (N = 5) and standard errors for various cover types on control and thinned 

312 

areas for Fall 1994a (pretreatment), Fall 1995, and Fall 1996. 

Sampling Period 

94 95 96 

Cover Type Treatment x SE x SE x SE 

Tree Control 36.4 3.9 39.9ax 5.2 39.2ax 5.7 

Thinned 25.5 2.6 7.9bx 3.0 9.2bx 3.1 

Total Control 7.1 1.1 6.9ax 1.1 9.2ax 2.2 

Herbaceous Thinned 6.8 0.5 12.2bx 0.8 22.6by 2.1 

Forb Control 1.4 0.3 1.5ax 0.5 1.5ax 0.5 

Thinned 1.8 0.3 4.9bx 0.5 8.6bx 1.2 

Grass Control 5.7 1.1 5.4ax 0.8 7.7ay 2.2 

Thinned 5.0 0.3 7.3bx 0.5 14.0by 1.0 

Bare Soil Control 36.0 3.6 35.6ax 2.0 35.7ax 2.7 

Thinned 42.9 2.7 27.4bx 0.7 21.7bx 1.3 

apretreatment means are presented for the reader's information; however, they were used as covariates in the 

repeated measures analysis and are not included in the multiple t-test evaluation of means. Means followed by the same 

letter (a,b,c), within a cover type and year, are not significantly different (P ~ 0.05). Means followed by the same letter 

(x,Y,z), within a cover type and treatment, are not significantly different. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 2-Species richness means (N = 5) and standard errors for various vegetation categories on 

control and thinned areas for Fall 1994a (pretreatment), Fall 1995, and Fall 1996. 

Sampling Period 

94 95 96 

Category Treatment x SE x SE x SE 

All Control 19.6 1.8 17.2ax 1.3 23.0ay 1.7 

Species Thinned 19.4 0.9 22.0bx 1.3 29.0by 1.09 

Forb Control 9.4 1.2 8.8ax 0.9 13.8ay 1.4 

Species Thinned 10.0 0.6 13.0bx 0.7 16.8by 1.2 

Grass Control 6.0 0.8 4.6ax 0.7 5.6ay 0.4 

Species Thinned 5.0 0.5 5.4bx 0.2 7.4by 0.6 

apretreatment means are presented forthe reader's information; however, they were used as covariates in the repeated 

measures analysis and are not included in the multiple t-test evaluation of means. Means followed by the same letter 

(a.'b~c), within a cover type and year, are not significantly different (P ~ 0.05). Means followed by the same letter (x,y,z), 

within a cover type and treatment, are not significantly different. 

(components of total herbaceous cover) both increased significantly following the thinning treatment but only grass 

cover had a significant time effect. 

Significant thinning and time effects were recorded for 

species richness for all vegetation categories (table 2). 

Discussion -------------------------------- The treatment achieved the immediate goals of reducing 

tree cover and bare soil cover. Total herbaceous plant 

cover on the treated area was twice that on the control area 

after one growing season and almost 2.5 x greater than 

controls after two growing seasons. Both forb and grass 

cover (the two components of total herbaceous cover) increased as a result of the treatment. Clearly, the objective of 

increasing herbaceous plant abundance was realized after 

only two growing seasons. 

The concept of biodiversity is important with respect to 

species preservation and ecosystem stability (Tilman 1996; 

Tilman and others 1996). Although species richness is not 

the best estimator of biodiversity response to disturbance 

(Barbour and others 1987), it is the only index that can be 

generated from the CSA data. The response observed in 

this study was probably due to a combination of climatic 

effects (increased rainfall may have resulted in more recorded species on both sites), and possibly to an improvement of our taxonomic skills. Most ofthe response in species 

richness is due to an increase in forb species. The number of 

grass species has remained relatively constant throughout 

the study. 

The next phase of the project is to re-introduce fire back 

into the treated area. The objective ofthe initial (restoration) 

fire will be to control the resprouting stumps and abundant 

seedling trees that were released from competition with the 

mature trees. There are often 15 to 20 seedlings existing 

under the canopy of a mature tree. If this cohort is not 

controlled the future density of trees on this site could be 

many times greater than the pretreatment density. The 

timing of the first burn is somewhat critical. Ifwe burn too 

soon, the fuel loads from the slash and herbaceous plants 

could be high enough to scorch and sterilize soils. However, 

if we wait too long to burn, the seedling trees and resprouting 

USDA Forest Service Proceedings RMRS-P-9. 1999 

stumps could get too big to be effectively controlled by the 

fire. Prescribed fire is most effective 3 to 5 years following 

mechanical treatments to control redberry or blueberry 

juniper resprouts in Texas (Erramouspe 1994). We anticipate conducting the initial prescribed fire sometime between 3 to 5 years post-treatment. 

Conclusions --------------------------------

The treatment method of hand-thinning trees in a degraded pinyon -j uni per woodland significan tly increased herbaceous plant abundance (without seeding) within 2 years at 

this site. Additionally, the treatment has significantly increased species richness. Although this method may not be 

as efficient at removing trees as techniques involving heavy 

equipment, it is much less destructive, and much more 

appropriate for sensitive areas. The treatment has initiated 

the process of ecosystem restoration. We plan to re-introd uce 

fire as a means to complete the restoration of the site and 

maintain the functional processes of a stable and productive 

grassland ecosystem. 

References ---------------------------------- Barbour, M. G.; Burk, J. H.; Pitts, W. D. 1987. Terrestrial plant 

ecology. Menlo Park, CA: The Benjamin/Cummings Publishing 

Company, Inc. 634 p. 

Betancourt, J. L. 1986. Paleoecology of pinyon-juniper woodlands: 

summary. In: Everett, R. L., compo Proceedings-pinyon-juniper 

conference; 1986 January 13-16; Reno, NV: Intermountain Research Station General Technical Report INT-215: 129-139. 

Buckman, R. E.; Wolters, G. L. 1986. Multi-resource management 

of pinyon-juniper woodlands. In: Everett, R. L., compo Proceedings-pinyon-juniperconference; 1986 January 13-16; Reno, NV: 

Intermountain Research Station General Technical Report INT215: 2-4. 

Burkhardt,J. W.; Tisdale, E. W.1976. Causes of juniper invasion in 

southwestern Idaho. Ecology 57: 472-484. 

Clements, F. E. 1936. Nature and structure of the climax. Journal 

of Ecology 24: 252-284. 

Dick-Peddie, W.A. 1993. Ecology and diversity of pinon-juniper 

woodland in New Mexico. In: Aldon, E. F.; Shaw, D. W., tech. 

coords. Managing pinon-juniper ecosystems for sustainability 

and social needs; 1993 April 26-30; Santa Fe, NM: Rocky Mountain Forest and Range Experiment Station General Technical 

Report RM-236: 72-73. 

313 
Erramouspe, R 1994. Juniper control begins with good grazing 

management. The Cattleman 91(6): 18-32. 

Grover, H. D.; Musick, H. B. 1990. Shrubland encroachment in 

southern New Mexico, U.S.A: An analysis of desertification 

processes in the American Southwest. Climatic Change 17: 

305-330. 

Jameson, D. A 1986. Climax or alternative steady states in woodland 

ecology. In: Everett, R L., compo Proceedings-pinyon-juniper 

conference; 1986 January 13-16; Reno, NV: Intermountain Research Station General Technical Report INT-215: 9-13. 

Miller, R F.; Wigand, P. E. 1994. Holocene changes in semiarid 

pinyon-juniper woodlands. Bioscience 44(7): 465-474. 

Miller, R G., Jr. 1981. Simultaneous statistical inference, 2nd 

edition. New York: Springer-Verlag. 299 p. 

Miller, R; Rose, J.; Svejcar, T.; Bates, J.; Painter, K. 1994. Western 

juniper woodlands: 100 years of plant succession. In: Shaw, D. W.; 

Aldon, E. F.; LoSapio, C., tech. coords. Desired future conditions 

for pinon-juniper ecosystems; 1994 August 8-12; Flagstaff, AZ: 

Rocky Mountain Forest and Range Experiment Station General 

Technical Report RM-258. Fort Collins,_CO: 5-8. 

Pase, C. P. 1981. Community structure analysis-a rapid, effective 

range condition estimator for semi-arid ranges. In: Lund, H. G.; 

314 

xxx tech. coords. Arid land resource inven tories: developing costefficient methods; 1980 Nov. 30-Dec. 6; La Paz, Mexico: U.S. 

Department of Agriculture, Forest Service General Technical 

Report WO-28, Washington, D.C: 425-430. 

Schlesinger, W. H.; Reynolds, J. F.; Cunningham, G. L.; Huenneke, 

L. F.; Jarrell, W. M.; Virginia, R A; Whitford, W. G. 1990. 

Biological feedbacks in global desertification. Science 247: 

1043-1048. 

SPSS Inc. 1990. SPSS Statistical Data Analysis, SPSSIPC + 4.0. 

Chicago, IL. 

Tilman, D. 1996. Biodiversity: population versus ecosystem stability. Ecology 77(2): 350-363. 

Tilman, D.; Wedin, D.; Knops, J. 1996. Productivity and sustainability influenced by biodiversity in grassland ecosystems. 

Nature 379:718-720. 

USDA Forest Service. 1993. Terrestrial ecosystem survey of the 

Santa Fe National Forest. Southwestern Region, Albuquerque, 

NM. 563 p. 

Van Devender, T. R; Betancourt, J. L.; Wimberly, M. 1984. Biogeographic implications of a packrat midden sequence from the 

Sacramento Mountains, south-central New Mexico. Quaternary 

Research 22: 344-360. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Applying Fire to Pinyon-Juniper 

Communities of the Green River Corridor, 

Daggett County, Utah 

Ivan Erskine 

Sherel Goodrich 

Abstract-Between 1984 and 1993, prescribed fire was applied to 

about 3,900 acres of pinyon-juniper woodland on the Ashley National Forest in the Green River corridor of Daggett County, UT. 

Prior to burning, much of the area was covered by mature and old 

stands of pinyon and juniper with little understory. Most of the 

burning required creating crown fires. Methods, results, and management implications of burning are discussed. 

Prior to a burning program that began in the 1980's, the 

pinyon-juniper belt on the Ashley National Forest in the 

Green River corridor of Daggett County, UT, was dominated by about 20,000 acres of nearly continuous stands of 

mature and old pinyon-juniper. Young stands of pinyonjuniper were advancing across the few areas where sagebrush-grass and mountain brush-grass communities were 

present. Objectives of burning included reducing pinyonjuniper in parts of the corridor with the intent of creating 

greater diversity of plant communities and more favorable 

habitat for wild sheep, elk, deer, and other wildlife. 

Methods and Results 

Prior to some of the burns, automated weather stations 

with voice recorders were placed in the vicinity of the 

proposed burns. Readings from these weather stations were 

accessed frequently by radio prior to and during burning. 

Readings from these weather stations were supported by 

measurements with portable field weather instruments. 

Burning experience under various weather conditions was 

used to develop prescriptions for prescribed burning. Weather 

conditions under which seven burns were conducted are 

listed in table 1. 

Some attempts at burning failed when conditions were 

not favorable. Under favorable conditions, as much as 1,100 

acres were burned in 1 day. The Goslin A burn indicates 

weather conditions not favorable for burning. Although 

windspeeds of 18 to 20 miles per hour, with gusts of up to 

34 miles per hour, were comparatively high for this burn, 

the low temperature (62 OF), higher relative humidity 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Ivan Erskine is Fire Management Officer and Sherel Goodrich is Forest 

Ecologist, U.S. Department of Agriculture, Forest Service, Ashley National 

Forest, Vernal, UT 84078. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

(26 percent), and cloud cover (10 to 30 percent) were not 

favorable. An afternoon of ignition attempts yielded 191 

acres of burning for the Goslin A burn. 

With an afternoon of ignition, 970 acres (Goslin II) and 

141 acres (Rifle Canyon A) were burned. Weather conditions associated with this burning included temperatures of75 to 79 OF, relative humidity of 15 to 18 percent, 

cloud cover of 0 percent, and winds of 10 to 25 miles per 

hour. With about 3 hours of ignition, 980 acres were 

burned at the Hideout East A burn, with temperatures of 

about 76 OF, relative humidity of 18 percent, cloud cover of 

o to 10 percent, and winds of 5 to 15 miles per hour. 

Experience at these and other burns listed in table 1 shows 

the importance of low-percent cloud cover as well as high 

temperatures and low humidity. This seems to be expected 

because these features are often related. Lower temperatures and higher humidity are generally associated with 

cloud cover. Even on a relatively clear day w hen burning was 

favorable, ignition and fire spread were greatly hampered 

when a passing cloud shaded the burn site from the sun. 

All of the burns listed in table 1 were ignited by helitorch. 

Other burns were ignited with drip torches by ground crews. 

Use of drainage bottoms as ignition sources was found to be 

highly useful. By using drainage bottoms as ignition sources, 

crown fires necessary for fire spread were started with 

comparatively little ignition time. 

Costs of treatment varied with successful attempts at 

burning. Cost of burning at one project included a failed 

attempt related to a training session when the schedule 

training session did not fall on days that were favorable for 

burning. Including this failed attempt in the cost, $9.54 per 

acre were spent in burning. Excluding the failed attempt, 

cost per acre was $4.54. Cost ofthe seed was $10.83 per acre, 

and cost of aerial application of seed was $4.17 per acre. 

Considering ideal conditions and the failed attempt, a range 

between $19.54 and $24.54 per acre (1989 dollars) is indicated for most projects. 

Watershed recovery and plant response were monitored 

on at least 12 study sites within these burned areas. Ground 

cover was reduced to near 0 by burning, and it remained low 

for one to two growing seasons after burning. High intensity 

storms washed considerable ash and some soil from some of 

the burned surfaces into drainage bottoms. However, within 

5 years, high percent ground cover was achieved (Goodrich 

and Huber, these proceedings; Goodrich and Reid, these 

proceedings), and little sediment movement was apparent 

after that time. 

Recovery of ground cover was more rapid in areas where 

vigorous understory communities were associated with 

young stands of pinyon-juniper than where understory 

315 
Table 1-Seven burns and weather conditions under which they were burned. 

Relative Cloud 

Burn Gradient Temperature humidity cover Wind8 

Acres Percent of Percent - - - - Miles per hour 

Hideout East A 980 15-60(85) 76 18 0-10 5-10(15) 

Jarvies Canyon A 301 (10)20-50 71 25 0-10 10-15(25) 

Jarvies Canyon B 223 20-60 71 25 0-10 10-15(25) 

Rifle Canyon A 141 5-30(60) 79 18 0 20-25 

Rifle Canyon B 160 5-60(80) 78 17 0 5-10(20) 

Goslin A 191 15-35 62 26 10-30 18-20(34) 

Goslin II 970 5-15 75 15 0 10-15 

aFor each burn, winds were from the southwest. Numbers in parentheses show the speed of gusts. 

communities had been depleted under closed stands of 

mature and old pinyon-juniper. Recovery of native understory plant communities was much more rapid where associated with young stands than where associated with mature and old stands. Seeded species and introduced annuals 

dominated the early seral communities where stands of 

mature and old pinyon-juniper were burned. Native species 

dominated early seral communities where young stands of 

pinyon-juniper were burned. Much greater diversity in 

early seral plant communities was found where young 

stands burned compared to mature and old stands (Huber 

and others, these proceedings). 

Forage benefits for elk and deer were readily apparent 

with large numbers of elk concentrating in these burns for 

parts of the year. Benefits to wild sheep are indicated to be 

slow in developing. Smith (1992) found that wild sheep 

used older burns where skeletons of mature pinyon-juniper 

had mostly fallen, but he found wild sheep avoided the 

recent burns where these skeletons were rather dense and 

where there was a flush of tall forage. Few to several 

decades are indicated for these burns to develop into highvalue habitat for wild sheep. However, wild sheep showed 

high preference for areas where open stands of pinyonjuniper had recently been burned. 

Management Implications 

Experience of burning pinyon-juniper in the Green River 

corridor indicates that temperatures of above 70 of, relative humidity of less than about 25 percent, and winds of 

10 to 30 miles per hour provide the most favorable conditions for burning. A Haines index (Haines 1988) of 5 or 6 

was helpful for large fire growth and successful burning. A 

Haines index of 5 or 6 indicates the lower atmosphere is dry 

and unstable. Cloud-free days are necessary for sustained 

fire spread. 

Crown fires are necessary to burn mature and old stands 

of pinyon-juniper with little understory. Ignition in drainage bottoms can help achieve crown fires. 

Longevity of burning as a habitat treatment in the pinyon-juniper belt of the Green River corridor is indicated to 

be 100 to 150 years or more (Goodrich and Barber, these 

proceedings). Comparatively low initial cost and longevity 

oftreatment indicate comparatively high economic returns 

316 

compared to chaining. However, burning leaves watersheds highly vulnerable to erosion for a few seasons after 

fire compared to chaining where debris is left in place. 

Fire is more easily applied to steep slopes, especially 

those likely to be selected by wild sheep, than chaining. Fire 

is more easily applied where slopes contribute to flame 

spread than on low gradients. However, in the Goslin II 

burn, over 900 acres were burned with one afternoon of 

ignition where gradients were commonly 5 to 15 percent. 

Fire perimeters are much less certain than with chaining 

or other mechanical treatments. Use of fire is indicated for 

areas where other methods are difficult to apply and where 

precise confinement of treatment is not critical. However, 

climatic features, fuel loading, and abundance of firetolerant species in early and mid-seral communities of this 

pinyon-juniper belt indicate an ecological history in which 

fire was a strong player. Escape of fire beyond prescribed 

boundaries has importance for manmade structures and 

other economic values, but the ecological history indicates 

this to be of little ecological relevance. 

Comparatively low cost and longevity are additional 

benefits for this treatment where it is appropriate in terms 

of habitat objectives and confinement constraints. 

Fire applied to open stands of relatively young pinyonjuniper has the following features: rapid recovery of in digenous understory plant communities, rapid recovery of 

ground cover sufficient for watershed and soil protection, 

and rapid improvement of favorable habitat for wild sheep. 

Fire applied to close stands of mature and old pinyonjuniper has the following features: slow recovery of indigenous understory plant communities with development of 

communities dominated by introduced annuals or seeded 

species, recovery of ground cover highly dependent on 

introduced annuals or seeded species, and slow improvement of favorable habitat for wild sheep. 

References __________________ _ 

Haines, D. A. 1988. A lower atmospheric severity index for wildfires. 

National Weather Digest. 13: 23-27. 

Smith, T. S. 1992. The bighorn sheep of Bear Mountain: ecological 

investigations and management recommendations. Provo, UT: 

Brigham Young University. 425 p. Dissertation. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Soil and Watershed Implications of Ground 

Cover at Burned and Unburned Pinyon-Juniper 

Sites at Rifle Canyon and Jarvies Canyon 

Sherel Goodrich 

Chad Reid 

Abstract - Quantity, dispersion, and quality of ground cover is 

compared for adjacent burned and seeded and unburned pinyonjuniper sites. Comparison of these features indicates greater soil 

protection for the burned and seeded site with 15 percent less bare 

soil and pavement and 24 percent greater vascular plant and litter 

cover 7 years post treatment. Ground cover is also compared 

between 5 and 10 years post burning and seeding at one site. This 

comparison indicates ground cover continued to increase for up to 10 

years post treatment. 

Total ground cover, dispersion of ground cover, and quality of ground cover appear to be highly important for soil and 

watershed protection (Blackburn and others 1986; Khan 

and others 1988; Osborn 1955; Payne 1980; Simanton and 

others 1991; Watters and others 1996). Over4 years, Farmer 

(1995) found an average offive times more runoff and eight 

times more sediment associated with a mature stand of 

pinyon-juniper than in all)lajacent area that had been 

chained and seeded with litte~1eft in place. The sites in the 

Ashley National Forest at Rifle Canyon and Jarvies Canyon 

were burned, which greatly reduced ground cover for lor 2 

years. However, within 7 years, plant and litter cover exceeded that found in a mature stand of pinyon-juniper, and 

ground cover continued to increase for up to 10 years. 

Study Sites ________ _ 

The study sites are located within the Green River corridorin Daggett County, Utah, where there areabout8,100 ha 

(20,000 acres) within a belt of Colorado pinyon (Pinus edulis 

Engelm.) and Utah juniper (Juniperus osteosperma [Torr.] 

Little) on the Ashley National Forest. The belt extends well 

beyond the National Forest boundary down river toward the 

Colorado and Utah line. Prior to the 1980's when a burning 

program was started within this area, pinyon-juniper formed 

nearly continuous stands and was advancing into the few 

remaining sagebrush/grass and mountain brush communities. Much of the belt on National Forest lands was closed to 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Shere! Goodrich is Forest Ecologist, Ashley National Forest, Forest Service, U.S. Department of Agriculture, Vernal, UT 84078. Chad Reid is 

Extension Agent, Utah State University Extension Service, Cedar City, UT 

84078. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

permitted livestock grazing in the 1960's as mitigation for 

recreation and other values associated with Flaming Gorge 

Reservoir. 

Low forage values for wild ungulates were recognized in 

this area with extensive stands of mature pinyon andjuniper covering much of the corridor and with young stands 

expanding into sagebrush/grass and mountain brush/grass 

communities. Bighorn sheep were of special concern as they 

were known to use the Green River corridor. Bighorn sheep 

avoided mature and old stands of pinyon and juniper (Smith 

1992). Burning and seeding of some sites were proposed and 

accomplished by the Ashley National Forest and Utah Division of Wildlife Resources. The Bureau of Land Management 

also burned some sites lower in the corridor. 

Prescribed fire was applied to pinyon-juniper woodlands 

at Jarvies Canyon in the fall of 1985 and in Rifle Canyon in 

September 1989. Study sites within these burns are about 

4.8 km (3 miles) west and about 2.4 km (1.5 miles) northwest 

of Dutch John, UT. Mean annual precipitation at the Flaming Gorge Climate Station near Dutch John is 31.75 cm 

(12.50 in) (Ashcroft and others 1992). The study sites are 

within the Uinta Mountain Section as defined by McNab and 

Avers (1994). They are within a landtype composed of ridge 

and ravine topography underlain by Precambrian quartzitic 

materials and shales of the Uinta Mountain Group. 

Within the landtype there are two general phases. One 

phase is on dip slopes of northerly exposures where alderleaf mountain-mahogany/bl uebunch w hea tgrass 

(Cercocarpus montanus Raf. / Elymus spicatus [Pursh] Gould) 

communities with high plant diversity are seral to pinyonjuniper. The other phase is on scarp slopes of southerly 

exposures where plant communities of big sagebrush (Artemisia tridentata N utt.) ,rubber rabbitbrush (Chrysothamnus 

nauseosus [Pallas] Birtt.), and grasses are seral to pinyonjuniper. On southerly exposures cheatgrass has proven to be 

highly competitive. It is generally oflower frequency on the 

northerly exposures. Both study sites reported here are on 

the phase with southerly exposures at about 2,042 m (6,700 

ft) elevation on gradients of about 20 to 40 percent. 

Both burns were aerial seeded in November or December 

of the same year in which they were burned. Seed for both 

sites was provided by Utah Division of Wildlife Resources. 

By weight, the seed mix at Jarvies Canyon included smooth 

brome (Bromus inermis Leysser) (20 percent), Piute 

orchardgrass (Dactylis glomerata L.), hard fescue (Festuca 

ovina var. duriuscula [1.] Koch.), Ladak alfalfa (Medicago 

sativa L.), and small burnet (Sanguisorba minor Scop.) (13 

to 14 percent each), and Fairway crested wheatgrass (Agropyron cristatum [1.] Gaertner), intermediate wheatgrass 

(Elymus hispidus [Opiz] Meld.), yellow sweetclover (Melilotus 

317 
Table 1-Comparison of ground cover at the Rifle Canyon burn site five growing seasons 

after treatment 

Treatment Veg. Litter Moss Rock Pave. Soil Total 

Burn and seeded (points) 31 a 202a 6 68a 23a 70a 400 

Unburned, not seeded (points) 18 134a 0 110a 54a 101 a 400 

Burn and seeded (percent) 8 50 1 17 6 18 100 

Unburned, not seeded (percent) 0 34 0 28 14 25 101 

"The spread in scores for these parameters between the two areas is indicated to be significant at 80 

percent probability (Chi Square = 1.642 with one degree of freedom). 

officinalis [L.] Pallas), and mountain big sagebrush (Artemisia tridentata var. paucif/ora Winward & Goodrich) (6 percent each). By weight, the seed mix at Rifle Canyon included: 

crested wheatgrass, orchardgrass, and ladak alfalfa (20 

percent each), and intermediate wheatgrass, smooth brome, 

hard fescue, and yellow sweetclover (10 percent each). The 

study site at Rifle Canyon provided a sharp contrast between burned and unburned areas. 

Methods and Results 

At the Rifle Canyon site, quantity of ground cover was 

compared in 1996 (7 years post treatment) by recording 

ground cover at 400 points along five belt lines 30.5 m (100 

ft) long in each ofthe burned and seeded and unburned sites. 

Results are shown in table 1. Frequency of plant species 

were recorded in 100 quadrats of 50 by 50 cm placed along 

the belt lines. Nested frequency was also determined in four 

plot sizes of 5 by 5 cm, 25 by 25 cm, 25 by 50 cm, within the 

50 by 50 cm quadrat which made up the fourth nested plot 

size (U.s. Department of Agriculture, Forest Service 1993). 

At the J arvies Canyon site, which is less than 3 miles away 

from the Rifle Canyon site, the same study methods described above were applied at five and 10 growing seasons 

postfire. Results are shown in table 2. 

At the Rifle Canyon Site, dispersion of ground cover was 

compared by line intercept measurements along the five 

belts for a total intercept of 152 m (500 ft) in each of the 

treated and untreated sites. Distance of intercept without 

live plant or litter cover was recorded. Range of variability 

for distance without live plant or litter cover was 0.3 to 2.7 

m (1 to 9 ft) for the burned and seeded area and 0.9 to 21 m 

(3 to 69 ft) for the mature pinyon-juniper stand. Mean 

distance of intercept without live plant or litter cover was 

0.82 m (2.7 ft) for the treated area and 5.4 m (17.6 ft) for the 

untreated area. 

Quadrat freq uency also indicates dispersion of plant cover. 

Seven years after treatment at Rifle Canyon, 86 of the 100 

quadrats (50 by 50 cm) contained perennial plants in the 

treated area compared to 37 of 100 in the mature pinyonjuniper stand. At the Jarvies Canyon site, perennial plants 

were found in 90 and 99 of the 100 quadrats 5 and 10 years 

post treatment, respectively. Comparison of perennial plants 

in nested plots of 25 by 25 cm also indicated dispersion of 

cover. In the mature pinyon-juniper stand at Rifle Canyon 

only 15 of100 plots had at least one perennial plant in them. 

In the burned and seeded area 59 of 100 plots had at least one 

perennial plant in them. At J arvies Canyon, 67 and 92 ofthe 

318 

100 nested plots of 25 by 25 cm had at least one perennial 

plant in them at 5 and 10 years post treatment, respectively. 

At the Rifle Canyon site, crown cover of pinyon andjuniper 

was also determined by line intercept along the five belts. On 

the untreated site, crown cover of pinyon was 20 percent, and 

for juniper it was 19 percent for a combined value of 39 

percent. On the treated area, crown cover was estimated by 

measuring the intercept of dead crowns. This indicated 

crown cover of 17 and 18 percent for pinyon and juniper, 

respectively, for a combined value of 35 percent. Similar 

crown cover for the two sites prior to the burn is indicated. 

Crown cover of trees was not determined at the J arvies 

Canyon site. However, density of skeletons indicated similar 

or greater cover of pinyon-juniper prior to burning. 

Essentially all the ground cover provided by live vegetation and litter in the untreated area was composed of basal 

area of trees and needles of these trees that were confined 

beneath the crowns of trees. Combined crown cover of pinyon 

and juniper on the untreated site was 39 percent. Combined 

ground cover of vegetation and litter was 34 percent. The 

litter of pinyon and juniper was composed of needlelike or 

scalelike leaves, cones, and broken twigs. The needlelike 

leaves of Colorado pinyon are 1.5 to 5 cm long, and the 

pistillate cones are ovoid and 2 to 5 cm long. The scalelike 

mature leaves of Utah juniper are 1 to 3 mm long with 

juvenile ones 2 to 8 mm long. The pistillate cones are 

subglobose and 6 to 12 mm thick (Welsh and others 1993). 

Ground cover in the burned and seeded area was composed of numerous fine stems comparatively closely spaced, 

which served to anchor litter. Stem length of grasses and 

forbs on the site varied from a few cm to over 1 m in length. 

Herbaceous litter consisted of comparatively fine, long, 

stems with branches or leaves that provided for a higher 

Table 2-Comparison of ground cover at 5 and 10 years following 

burning and seeding at the Jarvies Canyon site. 

Year Veg. Litter Moss Rock Pave. Soil Total 

1991 (points) 24a 117a 0 93a 47 119* 400 

1996 (points) 96a 184a 35a 39 45a 400 

1991 (percent) 6 29 0 23 12 30 100 

1996 (percent) 24 46 0 9 10 11 100 

"The spread in scores for these parameters between the 2 years is indicated 

to be significant at 80 percent probability (Chi Square = 1.642 with one degree of 

freedom). The lower value for rock in 1996 is considered a function of plant and 

litter cover spreading across exposed rock and not from rock being removed from 

the site. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
interlocking and lodging oflitter than on the untreated site. 

This herbaceous litter was associated with course woody 

debris of pinyon and juniper trees that had fallen since the 

fire in addition to the basal area of the trees that remained 

standing. As expected cheatgrass increased rapidly in the 

burned area, and higher ground cover here was a function of 

this species as well as the seeded species. 

Discussion --------------------------------- Exposed soil and small gravel fragments are easily displaced by the forces of water especially as gradients increase. Live and dead plant material and rock provide cover 

that can protect soils from the forces of water. Ground cover 

is the principle protection against both raindrop splash and 

sheet erosion (Farmer 1995; Osborn 1955; Blackburn and 

others 1986). Plant cover at or near the ground surface is 

more effective than canopy cover for preventing erosion 

(Siman ton and others 1991; Khan and others 1988) . Watters 

and others (1996) found basal cover, average distance to 

nearest perennial plant, and frequency of quadrats with no 

rooted perennial plant showed strong relationships to a 

subjective site stability rating for determining the point at 

which accelerated erosion occurs. 

Quality of ground cover is indicated by how well it is 

anchored or how well it is able to stay in place under rain 

drop splash and surface flow of water. Rooted vegetation has 

greater ability to stay in place than detached litter. Dispersion of ground cover is important to quality of cover. Vegetation with many fine stems well dispersed provides the best 

protection (Osborn 1955). This well dispersed, rooted vegetation also helps keep detached litter in place. Length and 

roughness oflitter also contribute to stability oflitter cover. 

Long pieces of flexible litter become interlocked more than 

do short, ridged pieces. Litter of stems with branches or 

leaves is more likely to interlock and lodge against live 

vegetation or larger woody debris than is litter composed of 

short, unbranched pieces. 

The shape of the pistillate· cones of pinyon and juniper 

(ovate to subglobose) greatly facilitate their movement down 

slope by water and gravity. The staminate cones disintegrate in to small fragments that are easily moved by water 

or wind. The pistillate cones were found in great numbers in 

the drainage bottom below the Rifle Canyon study site. The 

short needles of pinyon and juniper form a comparatively 

incohesive duff beneath the trees that is held in place by the 

base of the tree and where it is somew ha t protected by the 

crowns of the trees. Where this litter is exposed to raindrop 

slash, it seems unstable compared to the litter of the burned 

site. 

Comparisons of runoff and movement of sediment were 

not made in this study. However, the conditions described 

above are similar to those described by Farmer (1995) where 

he found an average offi ve times more runoff and eight times 

more sediment produced in a mature or old pinyon-juniper 

stand than on a treated area. However, the treated area in 

his study had been chained and seeded with debris left in 

place. Much higher levels of woody debris can be expected in 

that treatment than with burning. Less watershed protection can be expected following burning. Davis and Harper 

(1990) found bare soil decreased from 47 percent before 

USDA Forest Service Proceedings RMRS-P-9. 1999 

treatment to 11 percent 3 years postchaining with debris left 

in place. Slower increase for soil cover is indicated for 

burning at Rifle Canyon where bare soil and pavement 

totaled 39 percent in the untreated area and 24 percent 7 

years post treatment in the burned and seeded area. 

However, the increase in quantity, quality, and dispersion 

of ground cover with burning and seeding at the Rifle 

Canyon site indicates a strong trend toward soil stability. 

Monitoring at the Jarvies Canyon site indicates recovery 

will continue for up to 10 years, after which high values for 

soil and watershed protection have been achieved. 

At the Rifle Canyon site, ground cover provided by vegetation and litter was 34 percent in the untreated area. In the 

treated area this cover was 58 percent 7 years post treatment. At the Jarvies Canyon site no comparison was made 

with comparable treated and untreated sites. However, 

between the fifth and 10th years postfire and seeding, 

ground cover increased from 35 to 79 percent. This increase 

of 44 percentage points is indicated by point data to be 

significant (see table 2). The higher quadrat frequency and 

nested frequency of perennial plants in the treated area also 

indicates higher dispersion of cover of many fine stems that 

are more closely spaced than found in the untreated area. 

In the untreated site at Rifle Canyon, a relationship of 

litter cover to crown cover oftrees is indicated by the similar 

values of 34 percent litter cover and 39 percent for crown 

cover of pinyon and juniper. This relationship is visibly 

conspicuous at this site. In the mature pinyon-juniper stand, 

little litter is deposited in the inters paces between trees 

where it is poorly anchored and of low structural quality. 

Comparatively rapid removal of what little litter is deposited in the interspaces is indicated by the barren nature of 

the interspaces. Thus, the interspaces which make up over 

60 percent of the surface are essentially devoid of plant and 

Ii tter cover. A man tle of exposed gravel-sized rock fragments 

(28 percent of cover) did provide a well dispersed cover in 

these interspaces, which is indicated to be quite effective in 

slowing erosion. However, this exposed rock cover is indicated to be a function of past erosion. In the high precipitation summer of 1997, rills were greatly expanded in spite of 

the pavement and gravel cover on the untreated area. In the 

treated area, rock as well as bare soil are being covered by 

vegetation and litter where rills were not greatly expanded 

in 1997. 

Management Implications 

Pinyon and juniper appear to have the capacity to dominate nearly all ecological sites within the thermal belt to 

which they are confined. With long-term absence of disturbance, crown closure of these trees increases with a decrease 

in understory plants. On some sites this is associated with 

lower total ground cover, spotty dispersion of ground cover, 

and lower quality of ground cover. On some sites these 

conditions are conducive to greater erosion and sediment 

delivery to drainages. 

However, pinyon and juniper communities appear to be 

self-sustaining in this condition. Strongly implied is a long 

history of erosion and sediment delivery as a function of 

pinyon-juniper dominance of some sites. In view of this 

history, Gifford (1987) made a point that the pinyon-juniper 

319 
type has sustained itself on many diverse landscapes over 

the past 5,000 years or more and where it has obviously been 

designed to withstand at least 5,000 years of extreme hydrologic events. The concept of pinyon and juniper being selfsustaining on eroding surfaces is supported by their presence on many of the exposed, eroding geologic strata of Utah 

that weather to badlands. This contributes to the concept of 

a broad ecological amplitude for these species including 

strata that are low in nutrients, repel water, and contain 

gypsum and other chemicals that might inhibit growth. 

Pinyon and juniper are also capable of dominating more 

productive alluvial soils. 

That pinyon and juniper are self-sustaining on nearly all 

soils and geologic strata within their thermal belt including 

eroding surfaces is a point ofthis paper. However, conditions 

conducive to erosion and sediment yield are associated with 

mature and old stands of pinyon and juniper on some areas. 

These areas present an opportunity to reduce erosion by 

reducing the presence of pinyon and juniper and increasing 

the presence of plants with numerous fine stems that are 

closely spaced that serves to increase the dispersion and 

quality of litter. 

The barren interspaces of the mature pinyon-juniper 

stand at the Rifle Canyon site collaborate the views of West 

and Van Pelt (1987), Everett (1987), and Bunting (1987)that 

these trees contribute to the death of herbs and shrubs that 

grow on these sites at earlier stages of succession, which 

creates barren interspaces that are then exposed to the 

forces of erosion as a function of pinyon-juniper dominance. 

The general lack of understory species on the untreated site 

is consistent with the view of Hironaka (1987) that the 

simple mix of overstory and lack of understory in mature 

stands makes classification based on climax unsatisfactory. 

Langbein and Schumm (1958) reported maximum sediment yields occur on areas where annual precipitation is 

between 25.4 cm (10 inches) and 35.5 cm (14 inches). Payne 

(1980) considered the pinyon-juniper belt of the Intermountain Region to generally fall within this range. Ronco (1987) 

noted precipitation in pinyon-juniper woodlands of the Great 

Basin does not appear sufficient to adequately support both 

trees and herbaceous vegetation. This is consistent with the 

view of Arnold (1959) that pinyon-juniper woodlands produce more sediment than other woodlands. Low percent 

ground cover and high rates of erosion might be expected to 

be inherent in some mature and old pinyon-juniper stands. 

This concept is strongly supported by the work of Farmer 

(1995) where over 4 years he found an average of five times 

more runoff and eight times more sediment associated with 

a mature stand of pinyon-juniper than in an adjacent area 

that had been chained and seeded with litter left in place. 

Data from the Rifle Canyon and Jarvies Canyon sites 

indicate development of potential ground cover will take up 

to 10 years or longer following fire. For 1 or 2 years, burning 

can be expected to greatly expose the soil surface to the forces 

of erosion compared to chaining where debris is left in place. 

However, pinyon-juniper communities are indicated to be 

self-sustaining under high rates of erosion. Thus short-term 

exposure to erosion is indicated to be well within the range 

of natural variability for these sites. 

The a bili ty of pinyon and j uni per to occu py, dominate, and 

to be self-sustaining on eroding surfaces indicates the preservation of many mature and old stands of these trees will be 

320 

associated with low watershed values. Perhaps the super 

dominance of plants with broad ecological amplitudes are 

not always appropriate indicators ofa broad range of values 

that might be achieved from a landscape. Pinyon andjuniper 

are capable of sustaining themselves on an eroding soil 

regime to which they are apparent contributors. Treatments 

like those at Rifle Canyon and Jarvies Canyon offer an 

opportunity for communities that indicate a soil building 

regime. 

Visual and structural values for mature and old pinyonjuniper stands for some wildlife species are important considerations. The point ofthis paper is not to justify wholesale 

elimination of pinyon-juniper from large areas. It is to 

recognize a range of values and opportunities within the 

pinyon-juniper thermal belt. The challenge is to obtain site 

specific data that will facilitate choosing appropriate sites to 

manage for a diversity of values (Goodrich, these proceedings). 

Where watershed protection and long-term soil productivity are values to be emphasized, early seral communities are 

indicated to be of higher value than are mature orold stands 

where canopy cover of these trees has reached 40 percent. 

Observations in other stands ofthe Dutch John area indicate 

high watershed values can be maintained with crown cover 

of pinyon and juniper of up to 10 to 15 percent (Huber and 

others, these proceedings). 

These features strongly indicate that choice of sites to be 

managed for mature and old stands should include areas of 

more gentle gradient and areas of high percent large rock 

where erosion hazards are comparatively low. Depth and 

duration of snow cover are comparatively low on the steep 

gradients of southerly exposure at the Rifle Canyon and 

Jarvies Canyon sites. This indicates high value ofthese sites 

for wintering wild ungulates for which early and mid seral 

communities are of higher forage value than late seral or old 

stands. This concept is supported by a study in central Utah 

where Davis and Harper (1990) found lower mortality of 

deer where their habitat included early seral communities 

compared to that of large stands of mature juniper-pinyon 

without openings of early seral communities. 

In the case of this study, in an area where nearly 8,100 ha 

(20,000 acres) within the pinyon-juniper thermal belt was at 

or trending toward mature and old pinyon-juniper stands, 

the treatment seems appropriate for diversity of habitats. 

Reduced rates of erosion could be an additional benefit 

where the slopes at Rifle Canyon and J arvies Canyon are 

only about 3.2 km (2 miles) above Flaming Gorge Reservoir. 

References --------------------------------- Arnold, J. F. 1959. Effects of juniper invasion on forage production 

and erosion. Your Range-Its Management. Tempe, AZ: Arizona 

Agricultural Extension Service Report 2: 17-18. 

Ashcroft, G. L.; Jensen, D. T.; Brown, J. L. 1992. Utah climate. 

Logan, UT: Utah State University, Utah Climate Center. 125 p. 

Blackburn, W. H.; Thurow, T. L.; Taylor, C. A. Jr. 1986. Soil erosion 

on rangelands. In: Proceedings, Range Monitoring Symposium, 

Society of Range Manage. Denver, CO. 31-39. 

Bunting, S. C. 1987. Use of prescribed burning injuniper and pinyonjuniper woodlands. In: Everett, R. L., compiler. ProceedingsPinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. 

Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station: 141-144. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Davis, J. N.; Harper, K. T. 1990. Weedy annuals and establishment 

of seeded species on a chainedjuniper-pinyon woodland in central 

Utah. In: McArthur, E. D.; Romney, E. M.; Smith, S. D.; Tuller, P. 

T., compilers. Proceedings-symposium on cheatgrass invasion, 

shrub die-off, and other aspects of shrub biology and management; 1989 April 5-7; Las Vegas, NV. Gen. Tech. Rep. INT-276. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 72-79. 

Everett, R L. 1987. Plant response to fire in the pinyon-juniper zone 

In: Everett, R L., compiler. Proceedings-Pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 152-157. 

Farmer, M.1995. The influence of anchor chaining on the watershed 

values of a pinyon juniper woodland in central Utah. Provo, UT: 

Brigham Young University. 46 p. Thesis. 

Gifford, G. F. 1987. Myths and fables and the pinyon-juniper type. 

In: Everett, R L., compiler. Proceedings-Pinyon-juniper conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT-215. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 34-37. 

Goodrich, S. These proceedings. Multiple use management based 

on diversity of capabilities and values within pinyon-juniper 

woodlands. In: Monsen, Stephen B.; Stevens, Richard; Tausch, 

Robin J.; Miller, Rick; Goodrich, Sherel, comps. 1998. Proceedings: ecology and management of pinyon-juniper communities 

within the Interior West; 1997 September 15-18; Provo, UT. 

Proc. RMRS-P-OOO. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 

Hironaka, M. 1987. Classification of the pinyon-juniper vegetation 

type. In: Everett, R L., compiler. Proceedings-Pinyon-juniper 

conference; 1986 January 13-16; Reno, NV. Gen. Tech. Rep. INT215. Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 199-201.Khan, M. J.; Monke, E. 

J.; Foster, G. R 1988. Mulch cover and canopy effects on soil loss. 

Trans. of the Amer. Soc. Agr. Engr. 31: 706-711. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Langbein, W. B.; Schumm, S. A 1958. Yield of sediment in relation 

to mean annual precipitation. America Geophysical Union, Trans. 

39: 1076-1084. 

McNab, W. H.; Avers, P. E.1994. Ecological subregions ofthe United 

States: Section descriptions. Administrative Publication WOWSA-5. Washington, DC: U.S. Department of Agriculture, Forest 

Service. 267 p. 

Osborn, B. 1955. How rainfall and runoff erode soil. In: Stefferud, A. 

editor. Water the yearbook of Agriculture 1955. Washington DC: 

U.S. Department of Agriculture. 126-135. 

Payne, J. F. 1980. A multi-site evaluation of pinyon-juniper chaining in Utah. Logan, UT: Utah State University. 77 p. Thesis. 

Ronco, F. Jr. 1987. Stand structure and function of pinyon-juniper 

woodlands. In Everett, R L., compiler. Proceedings-pinyon-juniper conference; 1986 January 13-16; Reno, NV: Gen. Tech. Rep. 

INT-215. Ogden, UT: U.S. Department of Agriculture, Forest 

Service, Intermountain Research Station: 14-22. 

Simanton, J. R; Weltz, M. A; Larsen. H. D. 1991. Rangeland 

experiments to parameterize the water erosion effects. J. Range 

Manage. 30: 44-49. 

Smith, T. S. 1992. The bighorn sheep of Bear Mountain: ecological 

investigations and management recommendations. Provo, UT: 

Brigham Young University. 425 p. 

U. S. Department of Agriculture, Forest Service. 1993. Rangeland 

ecosystem analysis and management handbook. FSH 2209-21. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Region. 4 ch. 

Watters, S.E.; Weltz, M. A; Smith, E. L. 1996. Evaluation ofa site 

conservation rating system in southeastern Arizona. J. Range 

Manage. 49: 277-284. 

Welsh, S. L.;Atwood, N. D.; Goodrich, S.; Higgins, L. C. 1993. A Utah 

flora. Provo, UT: Brigham Young University Print Services. 986 p. 

West, N. E; Van Pelt, N. S. 1987. Successional patterns in pinyonjuniper woodlands. In: Everett, R L., compiler. Proceedingspinyon-juniper conference; 1986 January 13-16; Reno, NV: Gen. 

Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station: 43-52. 

321 
Use of OUST® Herbicide to Control 

Cheatgrass in the Northern Great Basin 

Mike Pellant 

Julie Kaltenecker 

Steven Jirik 

Abstract-The herbicide OUS'f® (sulfometuron methyl) is being 

used on rangelands in the northern Great Basin to control cheatgrass 

(Bromus tectorum) for 1 to 2 years, thereby improving the success of 

rehabilitation projects. Experimental data indicate that OUS'f® 

provides more effective cheatgrass control than either burning or 

disking. OUS'f® was applied to a 100-acre cheatgrass-infested 

seeding near Mountain Home, Idaho, where it reduced cheatgrass 

density by 91 percent compared to an adjacent untreated control. 

Remnant perennial grasses were more vigorous in the OUS'f® 

treatment. OUS'f® can be used to effectively control cheatgrass for 

up to 2 years at a cost of$25-$28 per acre (herbicide and application 

costs), using either ground or aerial application. 

The Problem: Exotic Annual Grass 

Invasion on Western Rangelands _ 

The introduction oftwo exotic annual grasses, cheatgrass 

(Bromus tectorum) and medusahead wildrye (Taeniatherum 

caput-medusae ssp. asperum), onto rangelands of the western United States was undoubtedly one of the most significant ecological events in North American history (Peters 

and Bunting 1994). Anthropogenic disturbances associated 

with settlement and growth of the human population, expansion of transportation systems and agriculture created 

openings in native plant communities for invasion and 

eventual dominance of exotic species (Mack 1981). Exotic 

annual grass accumulation in the understories of native 

shrub communities creates a continuum offine, combustible 

fuels (Billings 1994), resulting in dramatic increases in 

wildfire frequency and size (Pellant 1990; Whisenant 1990). 

These exotic species have adapted to a broader range of 

habitats, including salt-desert shrub and pinyon-juniper 

(Pinus-Juniperus) communities, resulting in the conversion 

of diverse natural landscapes to fire-maintained annual 

grass rangelands (Billings 1994; Monsen 1994; Sparks and 

others 1990). 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.s. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Mike Pellant is Rangeland Ecologist, U.S. Department of the Interior, 

Bureau of Land Management, Idaho State Office, Boise, ID 83709. Julie 

Kaltenecker is Research Assistant, Boise State University and U.S. Department of the Interior, Bureau of Land Management, Idaho State Office. 

Steven Jirik is Rangeland Management Specialist, U.S. Department of the 

Interior, Bureau of Land Management, Lower Snake River District, Boise, ID 

83705. 

322 

The establishment and spread of cheatgrass and the 

subsequent wildfires have had serious impacts on wildlife 

habitat and populations. Habitat loss has resulted in population declines for shrubland-obligate wildlife, ranging from 

breeding birds and rodents to wintering ungulates (Knick 

and Rotenberry 1995; McAdoo and Klebenow 1978). Food 

web dynamics are modified by loss of forage for herbivorous 

species and breeding habitat for both prey and predators. 

Herbivores exert additional pressure on the remaining native plant community resulting in depletion of forage and 

browse (McAdoo and Klebenow 1978). Livestock can be 

similarly affected by loss of forage following wildfire. 

The costs associated with wildfire suppression and rehabilitation are also growing as wildfires increase due to the 

pervasiveness of flammable annual grasses in the Great 

Basin (Pellant 1990). Additional concerns arise as more 

people move to urban-wildland interfaces and wildfire threats 

to private property increase. The issues surrounding the 

impacts of cheatgrass and associated wildfires will continue 

to grow unless effective and economical control treatments 

are applied on selected cheatgrass rangelands. 

Traditional Cheatgrass Control 

Methods 

Traditional methods to control cheatgrass-livestock 

grazing, burning, mechanical (disking or plowing), or broadspectrum herbicides-have all been used with varying degrees of success. Results are highly dependent on timing of 

treatment application with regards to cheatgrass phenology, soil moisture, and pre- and post-treatment climatic 

conditions (Hull and Holmgren 1964). Livestock grazing 

prior to seedripe can reduce biomass and seed production, 

however heavy use will only partially suppress cheatgrass 

while resulting in negative impacts to perennial grasses 

(Young and Tipton 1990) and biological soil crusts (Beymer 

and Klopatek 1992; Brotherson and others 1983). Burning 

prior to seed maturity can significantly reduce cheatgrass 

density (Pechanec and Hull 1945; Stark and others 1946; 

Stewart and Hull 1949), although results are variable due to 

the failure of fire to deplete the soil seed reserve and the 

enhanced seed production of post-fire cheatgrass plants. 

Plowing or disking can be effective if done before seedripe, 

and if the existing seed bank is buried at least 2.5 inches 

(Hulbert 1955), however treatment of steep or rocky areas 

may be impractical. 

Herbicide use on public lands was limited until 1991 when 

the Final Environmental Impact Statement for Vegetation 

Treatment on BLM Lands in Thirteen Western States 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 1-Seedbed preparation treatments applied to degraded rangeland in the 1992 Elko 

Cheatgrass Suppression Study. 

Treatment type Description Acres treated 

Mechanical Disk plow with double offset disk after germination 3.9 

with at least 1 inch of growth but prior to dough stage. 

Burn Controlled burn prior to cheatgrass seedripe. 4.5 

OUST® herbicide Spring application at 1.0 oz/acre prior to seedripe. 2.5 

Control No treatment. 

(USDI 1991) was approved, allowing the use of 21 herbicides to control cheatgrass and other weeds. Factors limiting 

the use of herbicides include chemical and application costs, 

selectivity, interception and inactivation of the chemical by 

surface litter, and weed seed longevity (Ogg 1994). Perceptions of the public about herbicides and their impacts on 

wildlife can also negatively influence the application of 

herbicides on public lands. 

OUST® (Sulfometuron Methyl) 

OUS'f® is a water-dispersible herbicide approved for use 

on rangelands in the 1991 Record of Decision for the Vegetation Treatment EIS (USDI 1991). OUS'f® functions as both 

a pre- and post-emergent herbicide through inhibition ofthe 

enzyme acetolactate synthase (ALS), which catalyzes the 

production of three amino acids: leucine, isoleucine, and 

valine (Keeler and others 1993; Boutsalis and Powles 1995). 

The ultimate result of ALS inhibition is death ofmeristematic tissue and eventual plant mortality (Keeler and others 

1993; Hofgen and others 1995). OUS'f® has low toxicity and 

does not accumulate in animal tissue, nor does it persist in 

the environment for extended periods (DuPont 1996). The 

half-life ranges from 20 to 100 days, depending on soil 

chemistry, temperature and moisture. If applied in the fall, 

OUS'f® requires rainfall to move into the soil where it kills 

germinating annual grasses. Spring-applied OUS'f® is absorbed by the roots and foliage of growing plants causing 

target plant mortality within 4 to 6 weeks. OUSTID should be 

applied prior to flowering to prevent viable seed production. 

OUST® affects actively growing tissue, thus it is effective 

in controlling rapidly growing annual plants. New spring 

growth of perennial plants may be stunted by 0 USTID but are 

generally not killed since they have established roots that 

penetrate below the level of the herbicide movement. 

Project Summaries 

1992 Cheatgrass Suppression Study, 

Elko, NV 

An experimental project was initiated in May 1992 near 

Elko, Nevada to compare cheatgrass control techniques on 

degraded rangeland prior to drilling with a perennial plant 

seed mixture. Strips within a 13 acre study area were 

USDA Forest Service Proceedings RMRS-P-9. 1999 

2.0 

treated with one of four seedbed treatments: burning, mechanical, herbicide, and control (table 1). The entire area 

was drilled with a perennial plant seed mixture using a notill Amazon drill in October 1992. Frequency data were 

collected in July 1993 and June 1994 using 10 nested plot 

frequency frames on five 50-ft transects in each treatment. 

OUS~ proved to be the most effective treatment for 

reducing cheatgrass, followed closely by burning (fig. 1). 

Both the OUS'f® and burning treatments maintained 

cheatgrass at lower frequencies than in the control in 1994 

(the second growing season). The disking treatment provided moderate cheatgrass control in 1993, however 

cheatgrass frequencies in the disked treatment exceeded 

even the control in 1994. Disking with an off-set plow rarely 

buries all cheatgrass seed and creates a disturbed seedbed 

that is ideal for post-treatment establishment of cheatgrass 

from the seedbank. 

No data on seeding success are presented here because the 

seed mixture was mistakenly applied at roughly one-half of 

the planned application rate. Seeded plant establishment 

was very spotty. The only species in the seed mixture that is 

present in more than a trace quantity today is 'Immigrant' 

forage kochia (Kochia prostrata), a perennial half-shrub 

imported from the steppes of Eurasia. 

100 

80 

~ 60 

g 

~ t:r 

f!! 40 u. 

20 

0 

Control Burn Disk OUST 

Figure 1-1992 Cheatgrass Suppression Study, 

Elko, NV. Frequency of cheatgrass recorded in 

0.0625 m2 frames. 

323 
1994 OUST® Pilot Project, Mountain Home, 10 

In April 1994, OUS~ was applied to a portion of a 

marginally established vegetative fuelbreak ("greenstrip") 

(Pellant 1990) near Mountain Home, Idaho. The site was 

originally plowed and seeded with a disk chain (Pellant 

1988) to a perennial grass and forb mixture in fall 1987. In 

1989, the original seeding was determined to be a failure 

due to an extended drought. To remedy this condition, a 

burn treatment was applied in September 1989, followed 

by drill-seeding with crested wheatgrass at 8 lb/acre in 

November 1989. This seeding was not successful due to 

cheatgrass competition and unfavorable climatic conditions 

after the seed application. Part of the site reburned in 

July 1993, providing an opportunity to test the use of 

OUS~ on 100 acres. OUS~ was applied at 1 ozlacre in 

April 1994 when cheatgrass was actively growing and prior 

to the boot stage. In September 1994, a multi-species seed 

mix comprised of approximately 50 percent crested wheatgrass was applied to the OUS~-treated area with a rangeland drill at 10.5Ib/acre. An unburned, untreated portion of 

the greenstrip was monitored as a control. 

Density of cheatgrass and crested wheatgrass plants in 

each area was determined along five 50-ft transects with 

10 plots per transect. Plot size was 0.0625 m2 for cheatgrass 

and 0.25 m2 for crested wheatgrass. Densities were converted to number ofplants/m2 for comparison oftreatments. 

Cheatgrass density was dramatically reduced by the 

OUS~ treatment compared to the control in 1995, 1996, 

and 1997 (figs. 2 and 3). Although cheatgrass increased in 

1996, densities remained below 100 plants/m2. Density of an 

exotic annual forb, bur buttercup (Ranunculus testiculatus), 

increased considerably from 1995 to 1996. This was probably due to a large, residual seedbank in the soil combined 

with decreased competition from cheatgrass. In 1997, bur 

buttercup density was substantially lower in the OUS~­

treated area compared to the control. The mechanism for 

this decline could be competition from the seeded crested 

wheatgrass combined with climatic influences. 

The effects of reduced cheatgrass competition on seeded 

species is demonstrated by the success of the crested 

Cheatgrass Bur Buttercup 

700 

600 

500 

~ 400 

.~ 

<Il 

0 300 

200 

100 

Control OUST Control OUST 

Figure 2-1994 OUST® Pilot Project, Mountain Home, 

10. Density (plants/m2) of cheatgrass and bur buttercup in control and OUST®-treated areas, 1995-1997. 

324 

Figure 3-1994 OUST® Pilot Project, Mountain Home, 

10. Control of cheatgrass (left side of photograph) by 

OUST® application in April 1994. The photograph was 

taken in June 1995. 

wheatgrass. Treatment with OUS~released existing crested 

wheatgrass plants from cheatgrass competition, resulting in 

improved plant vigor ofthe remnant perennial grasses in the 

treated area compared to the control in 1995. The perennial 

plants in the treatment area had greater biomass and 

number of seedstalks compared to similar plants in the 

control. They were also a darker green, possibly indicating 

more efficient use of available nitrogen where cheatgrass 

competition was reduced. 

Treatment with OUS~ also promoted the establishment 

of crested wheatgrass in the first growing season. An average of17 crested wheatgrass seedlings/m2 established in the 

seeded treatment during the 1996 growing season (fig. 4). 

Crested wheatgrass densities were considerably lower in 

1997 due to seedling mortality, but were still twice as great 

in the treatment area compared to the control. 

30 

25 

20 Includes 17 seedlings/m2 

~ 

.~ 15 Q) 

Q 

10 

Control OUST 

Figure 4-1994 OUST® Pilot Project, Mountain 

Home, 10. Density (plants/m2) of crested wheatgrass in control and OUST®-treated areas, 1995-

1997. The OUST® treatment was seeded in 

September 1994; the control was not seeded in 

1994. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 2-Comparison of cost and efficiency of ground and aerial application of 

OUST® herbicide. 

Ground Aerial 

Herbicide cost ($) 

Application cost ($) 

Average acres treated/day 

10.50/oz 

11.00-15.00/acre 

50-100 (60 ft boom) 

10.50/oz 

8.00-18.00/acre 

1500-2000 (45 ft boom) 

Operational Use of OUST® 

In 1996, the Bruneau Resource Area in the BLM's Lower 

Snake River District began using OUS'f®to control cheatgrass 

in large post-wildfire rehabilitation projects in the Snake 

River Birds of Prey National Conservation Area. Cheatgrass 

and wildfires are two of the greatest management concerns 

in this area which supports North America's largest concentration of nesting raptors (Kochert and Pellant 1986). Once 

cheatgrass density is reduced byOUS'f®, rehabilitation with 

perennial vegetation, especially shrubs, is conducted to 

reestablish habitat for raptor prey species and groundnesting birds, and provide livestock forage. 

Ground and aerial application methods are being evaluated to determine the most practical and cost-effective 

OUSTl"D application procedures. While herbicide and application costs are similar for ground and aerial application 

(table 2), trade-offs exist with regards to the amount of 

rangeland that can be treated per day and the impacts of 

label restrictions for each application method (DuPont 

1996, 1997). Aerial application is recommended for large 

tracts ofland and treatment of rocky sites that might cause 

application equipment damage. However, small tracts with 

adjacent cropland or dwellings are better treated with 

ground application, where no buffer is required as opposed 

to the 200 ft "no treatment" buffer required for all aerial 

applications. 

There are a number of label restrictions associated with 

the use ofOUS'J'® on non-crop lands. Application ofOUS'f® 

requires equipment dedicated for non-crop use. Application 

equipment cannot be used on cropland once it is used to 

apply OUSTl"D. Livestock use of treated rangeland cannot 

occur within 1 year of application. Because of the potential 

persistence of the herbicide in soil, seeding into the treatment area should be delayed for one growing season. Both 

aerial and ground application require wind speeds between 

3 and 10 mph. OUSTl"D cannot be applied on frozen ground. 

OUSTl"D can be applied in late fall or early spring to control 

cheatgrass. Initial observations indicate that fall application ofOUS'J'® provides better cheatgrass control than spring 

application since both fall- and spring-germinated cheatgrass plants are killed. However, viability tests on cheatgrass seeds and results from previous projects (for example, 

the 1994 OUS'f® Pilot Project) indicate that spring treatments may be effective if application is done in advance of 

seed ripening. 

Most native perennial plants are not adversely impacted 

by an OUSTl"D application of 1.0 ozlacre, however a temporary chlorosis and stunted growth is often observed on 

treated areas. Sandberg bluegrass (Poa secunda) has been 

observed to suffer some mortality following spring OUS'J'® 

application at 1 ozlacre. Viability of seed produced by native 

plants may be reduced in treated areas, affecting potential 

USDA Forest Service Proceedings RMRS-P-9. 1999 

recruitment during the first growing season following 

OUST® application. Monitoring studies established on 

treated areas will provide more quantitative information on 

the effects of OUS'J'® on native vegetation. 

Ongoing Studies 

Initial results indicate that OUS'J'® is an effective tool for 

cheatgrass control over a 1 to 2 year period, allowing release 

of native and seeded perennial species from cheatgrass 

competition. Studies are currently being conducted by the 

USDA Forest Service, Rocky Mountain Research Station, 

Boise State University, and the USDI Bureau of Land 

Management to determine: 1) minimum application rate 

that provides effective cheatgrass control; 2) effectiveness of 

fall versus spring application; 3) effects of OUS'f® on survival and reproduction of native plants and microbiotic 

crusts; 4) effects of OUS'f® on germinating (seeded) perennial plants; and 5) effectiveness of OUS'J'® in controlling 

medusahead wildrye. Results from these studies will provide managers with better guidelines on the use of OUS'J'® 

in the management and rehabilitation of cheatgrassinfested rangelands. 

References --------------------------------- Beymer, Renee J.; Klopatek, Jeffrey M. 1992. Effects of grazing on 

cryptogamic crusts in pinyon-juniper woodlands in Grand 

Canyon National Park. American Midland Naturalist. 127: 

139-148. 

Billings, W. D. 1994. Ecological impacts of cheat grass and resultant 

fire on ecosystems in the western Great Basin. In: Monsen, 

Stephen B.; Kitchen, Stanley G., comps. 1994. Proceedingsecology and management of annual rangelands; 1992 May 18-21; 

Boise, ID. Gen. Tech. Rep. INT-GTR-313. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Intermountain Research Station: 22-30. 

Boutsalis, P.; Powles, S. B. 1995. Resistance of dicot weeds to 

acetolactate synthase (ALS)-inhibiting herbicides in Australia. 

Weed Research. 35: 149-155. 

Brotherson, Jack D.; Rushforth, Samuel R; Johansen, Jeffrey R 

1983. Effects of long-term grazing on cryptogam crust cover in 

Navajo National Monument, Ariz. Journal of Range Management. 36(5): 579-58l. 

DuPont Agricultural Products. 1996. OUS'f® herbicide product 

label. Wilmington, DE: E. 1. du Pont de Nemours and Company, 

DuPont Agricultural Products. 9 p. 

DuPont Agricultural Products. 1997. Special local need 24<D 

labeling:OUS'f® herbicide for noncropland weed control, State of 

Idaho. Wilmington, DE: E. 1. du Pont de Nemours and Company, 

DuPont Agricultural Products. 1 p. 

Hbfgen, R.; Laber, B.; Schtittke, 1.; Klonus, A.; Streber, W.; Pohlenz, 

H. 1995. Repression of acetolactate synthase activity through 

antisense inhibition. Plant Physiology. 107: 469-477. 

Hulbert, L. C. 1955. Ecological studies of Bromus tectorum and 

other annual bromegrasses. Ecological Monographs. 25: 181-213. 

325 
Hull, A C., Jr., Holmgren, R C. 1964. Seeding southern Idaho 

rangelands. Res. Pap. INT-I0. Ogden, UT: U.S. Department of 

Agriculture, Forest Service, Intermountain Forest and Range 

Experiment Station. 31 p. 

Keeler, S. J.; Sanders, P.; Smith, J. K.; Mazur, B. J. 1993. Regulation 

of tobacco acetolactate synthase gene expression. Plant Physiology. 102: 1009-1018. 

Knick, Steven T.; Rotenberry, John T. 1995. Landscape characteristics offragmented shrubsteppe habitats and breeding passerine 

birds. Conservation Biology. 1059-1071. 

Kochert, M. N.; Pellant, M. 1986. Multiple use in the Snake River 

Birds of Prey Area. Rangelands. 8: 217-220. 

Mack, R N. 1981. Invasion of Bromus tectorum L. into western North 

America: an ecological chronicle. Agro-Ecosystems. 7: 145-165. 

McAdoo, J. Kent; Klebenow, Donald A 1978. Native faunal relationships in sagebrush ecosystems. In: The sagebrush ecosystem: a 

symposium; 1978 April; Logan, UT. Logan, UT: Utah State 

University: 50-61. 

Monsen, Stephen B. 1994. The competitive influences of cheatgrass 

CBromus tectorum) on site restoration. In: Monsen, Stephen B.; 

Kitchen, Stanley G., comps. 1994. Proceedings-ecology and management of annual rangelands; 1992 May 18-21; Boise, ID. Gen. 

Tech. Rep. INT-GTR-313. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 43-50. 

Ogg, Alex G., Jr. 1994. A review of the chemical control of downy 

brome. In: Monsen, Stephen B.; Kitchen, Stanley G., comps. 1994. 

Proceedings-ecology and management of annual rangelands; 

1992 May 18-21; Boise, ID. Gen. Tech. Rep. INT-GTR-313. Ogden, 

UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 194-196. 

Pechanec, J. F.; Hull, A C., Jr. 1945. Spring forage lost through 

cheatgrass fires. National Wool Grower. 35: 13. 

Pellant, Mike. 1988. Use of disk chain on southern Idaho's annual 

rangeland. In: 42d annual report, Vegetative Rehabilitation 

Equipment Workshop; 1988 February 21-22; Corpus Christi, TX. 

Missoula, MT: U.S. Department of Agriculture, Forest Service, 

Missoula Technology Development Center: 40. 

Pellant, Mike. 1990. The cheatgrass-wildfire cycle-are there any 

solutions? In: McArthur, E. Durant; Romney, Evan M.; Smith, 

Stanley D.; Tueller, Paul T., comps. Proceedings-symposium on 

cheatgrass invasion, shrub die-off, and other aspects of shrub 

biology and management; 1989 April 5-7; Las Vegas, NV. Gen. 

Tech. Rep. INT-276. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station: 11-17. 

326 

Peters, Erin F.; Bunting, Stephen C. 1994. Fire conditions preand post-occurrence of annual grasses on the Snake River Plain. 

In: Monsen, Stephen B.; Kitchen, Stanley G., comps. 1994. 

Proceedings-ecology and management of annual rangelands; 

1992 May 18-21; Boise, ID. Gen. Tech. Rep. INT-GTR-313. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 31-36. 

Sparks, Steven. R; West, Neil. E.; Allen, Edith. B. 1990. Changes in 

vegetation and land use at two townships in Skull Valley, western 

Utah. In: McArthur, E. Durant.; Romney, Evan M.; Smith, 

Stanley D.; Tueller, Paul T., comps. Proceedings-symposium on 

cheatgrass invasion, shrub die-off, and other aspects of shrub 

biology and management; 1989 April 5-7; Las Vegas, NV; Gen. 

Tech. Rep. INT-276. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station: 26-36. 

Stark, R H.; Toevs, J. L.; Hafenrichter, A L. 1946. Grasses and 

cultural methods for reseeding abandoned farmlands in sou thern 

Idaho. Bull. 267. Moscow, ID: Idaho Agricultural Experiment 

Station. 36 p. 

Stewart, G.; Hull, A C., Jr. 1949. Cheatgrass (Bromus tectorum L.)-

an ecological intruder in southern Idaho. Ecology. 30(1): 58-74. 

U.S. Department of the Interior. 1991. Final Environmental Impact Statement for Vegetation Treatment on BLM Lands in 

Thirteen Western States. Casper, WY: U.S. Department of the 

Interior, Bureau of Land Management. 

Whisenant, Steven G. 1990. Changing fire frequencies on Idaho's 

Snake River Plains: ecological and management implications. 

In: McArthur, E. Durant.; Romney, Evan M.; Smith, Stanley D.; 

Tueller, Paul T., comps. Proceedings-symposium on cheatgrass 

invasion, shrub die-off, and other aspects of shrub biology and 

management; 1989 April 5-7; Las Vegas, NV; Gen. Tech. Rep. 

INT-276. Ogden, UT: U.S. Department of Agriculture, Forest 

Service, Intermountain Research Station: 4-10. 

Young, James A; Tipton, Frosty. 1990. Invasion of cheat grass into 

arid environments of the Lahontan Basin. In: McArthur, E. 

Durant; Romney, Evan M.; Smith, Stanley D.; Tueller, Paul T., 

comps. Proceedings-symposium on cheatgrass invasion, shrub 

die-off, and other aspects of shrub biology and management; 1989 

April 5-7; Las Vegas, NV; Gen. Tech. Rep. INT-276. Ogden, UT: 

U.S. Department of Agriculture, Forest Service, Intermountain 

Research Station: 37-40. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Development of Native Seed Supplies to 

Support Restoration of Pinyon-Juniper Sites 

E. Durant McArthur 

Stanford A. Young 

Abstract-Use of native plants for restoration and rehabilitation of 

disturbed or manipulated pinyon-juniper communities is increasing in response to desires ofland managers and society in general. 

Seeds of native plants are becoming more available, but estimates 

and surveys show there is still more demand than available supply. 

Field grown seeds and warehousing do anticipate demand but are 

only partial solutions to the native plant seed shortage. Exotic, 

developed plant materials, especially Triticeae grasses and legumes, remain important resources for rehabilitation plantings. 

Private industry seed collectors, growers, and developers will be 

responsive to plant materials needs ofland managers. Seed genetic 

identity and quality can be better assured through the seed certification process whether the seed is wildland collected or field grown. 

After pinyon -j uni per si tes have been disturbed or depleted 

by natural or managed events such as prescribed or wildfire, 

chaining, or chopping, the rehabilitation and restoration of 

those sites often requires seeding. Seed for this purpose has 

traditionally been obtained by harvesting seed from native 

stands and from cultivated fields of mostly non-native plants 

(McArthur 1988; Meyer and Kitchen 1995; Monsen 1987; 

Plummer and others 1968; Roundy 1996). Seed suppliers, 

whether they be wildland seed collectors or those who grow 

various classes of non-selected common or developed plant 

germplasms, seek to respond to market needs (Plummer 

1984; Young and others 1995). 

Traditional objectives for pinyon-juniper rehabilitation 

were to provide stability to soils, and forage and cover for 

livestock and big game anima:ls (Plummer and others 1968; 

Roundy 1996). The most important criteria for use of particular plant materials was their site adaptability and the 

resource values that they provided (Monsen and McArthur 

1995). The early success in pinyon-juniper rehabilitation 

and conversion projects as well as other rangeland rehabilitation efforts were highlighted by the performance of exotic 

grasses, especially members of the Triticeae (wheatgrasses 

and their relatives), and legumes (rangeland alfalfas and 

clovers) (Asay and Knowles 1985a,b; Barnes and Sheaffer 

1985; McArthur 1988; Plummer and others 1968; Roundy 

1996; Rumbaugh and Townsend 1985;). Triticeae grasses 

and legumes remain the plants of greatest availability and 

primary choice for most pinyon-juniper rehabilitation 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

E. Durant McArthur is Project Leaderwith the Shrub Sciences Laboratory, 

Rocky Mountain Research Station, Forest Service, U.S. Department of 

Agriculture, Provo, UT 84606-1856. Stanford A. Young is Secretary-Manager 

of the Utah Crop Improvement Association, Utah State University, Logan, 

UT 84322-4855. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

plantings. However, more and more native plant materials 

(grasses, forbs, and shrubs) are becoming available (Carlson 

and McArthur 1985; McArthur 1988; Meyer and Kitchen 

1995; Monsen 1987; Monsen and Stevens in press; Young 

and others 1995;). 

In recent years there has been increasing interest in 

reconstructing natural plant communities and using siteindigenous and other regionally native plant materials (Allen 

and others 1997; Jordan and others 1987; Richards and 

others 1998; Roundy and others 1995). Governmental land 

management agencies (such as the U.S. Department of 

Agriculture, Forest Service; U.S. Department ofthe Interior, 

Bureau of Land Management; Utah Department of Natural 

Resources, Divison of Wildlife Resources) have instituted 

policies to require, or at least encourage, the use of native 

plant materials in rehabilitation plantings (Richards and 

others 1998; Richard Stevens personal communication). 

The practice of restructuring or recreating natural, preexisting plant communities has been termed "restoration" 

(Allen 1995; Jordan and others 1987). Rehabilitation implies a renewal of land productivity but a change in the 

ecosystem structure (Allen 1995). This paper reviews the 

status ofthe native plant seed industry in wildland rehabilitation and restoration. While we emphasize pinyon-juniper 

lands, our somewhat broader discussion incl udes other wildland plant community types. 

Materials and Methods 

We present survey information from the reclamation seed 

industry in two different formats. One of us (SAY) compiled 

a summary of market information for selected reclamation 

species emphasizing native plants and other conservation 

plant materials for presentation at the 1997 Utah Native 

Plant Forum. Data included current use, potential use, 

amount available as wildland collected seed, and price 

information for the Intermountain and Pacific Northwest 

Regions (Utah, Nevada, Idaho, Montana, Oregon, Washington). In this report we have included and updated much of 

that information. 

The second source is a survey conducted by our colleague 

Richard Stevens of the Utah Division of Wildlife Resources, 

also for the 1997 Utah Native Plant Forum. This survey 

reported the volume of native seed sold in 1996 by five Utah 

seed companies. The volume of seed is given to indicate a 

trend and not meant to be definitive, although Stevens 

(personal communication) estimates these companies account for at least halfofthe native seed volume by Utah seed 

companies. The seed sold by these Utah seed companies was 

collected and sold both in and out of Utah. 

327 
Results and Discussion 

Market information estimates for 47 species from the 

Intermountain and Pacific Northwest regions show that 

potential use of these species-nearly 2.5 million lb pure live 

seed (pls)-far outstrips the current use (approximately 

750,000 lb pIs) and the volume available from harvest of 

wildland stands (approximately 370,000 pounds pIs) (table 1). 

This information demonstrates that there is not enough seed 

collected nor available to be collected from wildlands to meet 

current demand, let alone potential usage, and that currently much of the demand is met from field-grown seed. The 

supply of native wildland-collected seed varies widely from 

year to year depending upon growing and collecting conditions, mainly weather. There is apparently a market for 

increasing field-grown seed for many species (table 2). The 

seed price estimates in table 1 emphasize this. Seed available from wildlands has higher val ue than current use val ue 

even though the volume of seed on wildlands is less than 

current use volume. This is because some high value wildland seed remains uncollected (table 2). 

The five Utah seed companies that were surveyed sold a 

total of more than 500,000 lb of native seed in 1996 including 

more than 300,000 lb of shrub seed, nearly 200,000 lb of 

grass seed, and 35,000 lb of forb seed (table 3). Many of the 

species sold were the same as those in the Intermountain 

and Pacific Northwest area survey (table 2), but many 

additional species are also listed. The Utah seed companies 

sold seed of29 native grasses, 39 native forbs, and 42 native 

shrubs (table 3). 

We believe the increasing demand for native species for 

restoration and rehabilitation plantings can be best met 

w hen the principal users stockpile seed so seed will be 

available when needed, whether that need is generated by a 

planned site rehabilitation or restoration or an emergency 

situation such as wildfire rehabilitation. Two successful 

examples of seed stockpiling are the Utah Division of Wildlife Resources Seed Warehouse in Ephraim and the Bureau 

of Land Management Seed Warehouse in Boise, ID. These 

warehouses maintain large s~ed inventories (more than 

200,000 lb) and a rich array of species. The Utah Division of 

Wildlife Resources has stockpiled native seed in its warehouse operation for more than 40 years. These seed resources have been used not only on Divison and other State 

lands, but on Federal and private lands as well. The Boise 

Bureau of Land Management seed warehouse has been 

servicing public land needs in Idaho and other Western 

Table 1-Market information estimates for 47 selected reclamation 

speciesa . 

Available for 

Current Potential wildland 

Factor use use collection 

Pure live seed 765,873 2,460,450 370,212 

(Ib/yr) 

Dollar value $3,232,749 $12,232,250 $3,261,417 

aSummary of data from table 2. Financial values determined as mid-point 

values for use, availability, and price to grower (table 2). 

328 

States since 1991. The National Forests in Utah are considering establishing a native seed warehouse. 

We believe these public sector warehouses are needed for 

timely response to rehabilitation and restoration needs on 

public lands. Furthermore, we suggest that orderly stockpiling would greatly encourage consistent production from 

private sector seed collectors and growers who will continue 

to supply most of the seeds for publicly owned warehouses. 

We antici pate that private warehousing of seed will con tin ue 

to serve as an adjunct to public warehousing. 

As natural resource managers' objectives turn increasingly toward the maintenance and restoration ofthe genetic 

and ecological integrity of native ecosystems, native plant 

use will also increase. In response to this trend, more native 

plant materials are becoming available (tables 1-3). However, ecosystem function and service are also important. In 

some places, such as drastically disturbed sites, the genetic 

and ecological robustness of developed, available, and sometimes exotic plants may be needed. Plant germplasm collectors and developers and the seed industry will respond to 

land managers' needs in both restoration and general rehabilitation arenas if those needs are viewed as consistent 

market commitments. 

Seed genetic identity and quality can best be assured if the 

seed is inspected and certified following the requirements 

and standards of the Association of Official Seed Certifying 

Agencies (AOSCA), whether the seed is wildland collected or 

field grown (Young 1995; Young and others 1995). Ifthe seed 

is tagged by an official seed certifying agency, the buyer can 

have confidence about the seed quality (mechanical purity, 

germination, foreign material), source or site of origin (genetic purity and identity), and ecotypic or developed status 

of the seed lot. 

Acknowledgments 

We thank Richard Stevens and Steve Monsen for encouragement in preparation ofthis manuscript, Richard Stevens 

for sharing his survey data with us, and Ron Stevenson 

(Stevenson Intermountain Seed Company) for assistance in 

compiling market data. We also thank Jeanne Chambers, 

Stan Kitchen, and Richard Stevens for reviews and comment on an earlier version of this manuscript. 

References --------------------------------- Allen, E. B. 1995. Restoration ecology: limits and possibilities in arid 

and semiarid land. In: Roundy, B. A.; McArthur, E. D.; Haley, 

J. S.; Mann, D. K, comps. Proceedings: wildland shrub and arid 

land restoration symposium; 1993 October 19-21; Las Vegas, NV. 

Ogden, UT: Gen. Tech. Rep. INT-GTR-315. U.S. Department of 

Agriculture, Forest Service, Intermountain Research Station: 7-15. 

Allen, E. B.; Covington, W. W.; Falk, D. A. 1997. Developing the 

conceptual basis for restoration ecology. Restoration Ecology 

5: 275-276. 

Asay, K H.; Knowles, B. P. 1985a. Current status and future of 

introduced wheatgrasses and wildrye for rangeland improvement. In: Carlson, J. R; McArthur, E. D., eds. Symposium: range 

plant improvement. 1985 February 11-15; Salt Lake City, UT. 

Denver, CO: Proceedings, selected papers presented at the 38th 

Annual Meeting of the Society for Range Management: 109-116. 

Asay, K H.; Knowles, R. P. 1985b. The wheatgrasses. In: Heath, M. 

E.; Barnes, R. F.; Metcalf, D. S., eds. Forages, the science of 

grassland agriculture, 4th edition. Ames, IA: Iowa State University Press: 166-176. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 2-Market information estimates for Intermountain and Pacific Northwest regions for 47 selected reclamation species, in pounds of pure 

live seed (pis). 

Avaliable wildland 

Species8 Current Use Potential use collected 

------------------------ pIs Iblyr - - - - - - - - - - - - - - - - - - - - - - -

Species ~ 10,000 Ib/yr 

Small burnetC,9 50,000-200,000 300,000 0 

Blue flaxd,9 20,000-40,000 100,000 0 

Western yarrowd 10,000-30,000 35,000-45,000 1,000-2,000 

Antelope bitterbrush 5,000-20,000 35,000-45,000 5,000-30,000 

Forage kochiac,9 25,000-40,000 100,000 40,000-60,000 

Wyoming big sagebrushe,f,9 4,000-20,000 25,000 35,000 

Fourwing saltbush9 40,000-BO,000 100,000 100,000 

Bottlebrush squirreltail 10,000-15,000 50,000-200,000 15,000 

Western wheatgrass9 BO,000-100,000 200,000 20,000-50,000 

Bluebunch wheatgrass9 -20,000-50,000 75,000-300,000 5,000 

Thickspike wheatgrass9 20,000-30,000 50,000 5,000 

Basin wildrye9 25,000-50,000 75,000-100,000 10,000-15,000 

Indian ricegrass9 20,000-40,000 50,000 100,000 5,000-20,000 

Stream bank wheatgrass9 20,000-30,000 50,000 0 

Mountain brome9 30,000-100,000 300,000 5,000 

Meadow brome9 20,000-50,000 100,000-200,000 0 

Slender wheatgrass9 50,000-100,000 250,000-300,000 1,000 

Species 1,000-9,999 Ib pls/yr 

Arrowleaf balsamroot 500-1,500 2,500-3,500 500-2,000 

Rocky Mountain Beeplant 500-2,500 3,000-5,000 3,000-5,000 

Palmer penstemon9 2,500-5,000 5,000-10,000 1,500-2,500 

Rocky Mountain penstemon9 3,000-B,000 B,000-10,000 1,000-1,500 

Common sunflower 2,000-5,000 10,000 10,000 

Sweet anise 500-2,500 2,500-5,000 2,500-5,000 

White-stemmed rubber rabbitbrushe,f 1,500-2,500 2,500 2,500 

Basin big sagebrushe,f 1,500-3,000 3,000 10,000 

Mountain big sagebrushe,f,9 2,000-5,000 6,000 10,000 

Winterfat9 5,000-10,000 20,000 5,000-15,000 

Sandberg bluegrass 200-2,000 25,000-100,000 3,000 

Needle-and-thread grass 500-10,000 50,000-70,000 1,000-15,000 

Species 100-999 Ib pls/yr 

Blueleaf astere 200-500 500-2,500 200-500 

Pacific astere 50-200 500-2,500 50-200 

Sulfur flower buckwheat 100-200 500-2,500 300-500 

Wyeth buckwheat 100-200 500-5,000 400-500 

Gooseberry-leaf globemallow 500-1,000 2,000-4,000 200-1,000 

Scarlet globemallow9 200-400 1,000-1,500 50-1,000 

Munroe globemallow9 300-1,000 1,000-2,000 200-1,000 

Showy goldeneye 500-1,000 1,000-2,000 200-500 

Firecracker penstemon 100-500 1,500-2,000 100-200 

Wasatch penstemon 200-1,000 1,500-2,000 100-500 

Louisana sagewort 100-400 500-2,500 200-400 

Oyster-plant salsifyc 100-250 500-1,500 500-1,500 

Utah sweetvetch9 500-1,000 5,000-B,000 500-1,000 

Species < 100 Ib/yr 

Gland cinquefoil 20-50 200-1,000 100-500 

Canada goldenrod 25-75 500-2,500 25-300 

Butterweed groundsel 10-50 200-2,000 10-100 

Nuttallomatium 25-100 500-2,500 50-200 

Thurber needlegrass 25-100 10,000-50,000 3,000 

aSpecies are divided into classes based on current use. 

bVendor price is some percentage above these figures, reflecting condition, warehousing, and other overhead costs and market conditions. 

CExotic or naturalized species. 

dCircumboreal species. 

eSeed is typically marketed at about 10 to 15 percent purity. 

'Subspecies. 

9Species or subspecies has released varieties and/or germplasm. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Price to grower 

or collectorb 

$Ip/s lIb 

0.40 

2.25-5.00 

5.00-7.50 

5.00-8.00 

7.00-12.00 

15.00-35.00 

2.50-6.00 

B.00-12.00 

2.50-6.00 

2.00-5.00 

2.00-4.00 

3.00-7.00 

2.00-5.00 

1.60-5.00 

1.00-2.00 

1.50-2.50 

1.50-2.50 

B.00-9.00 

B.OO- 9.00 

9.00-12.00 

12.00-15.00 

3.00 

5.00-7.00 

15.00 

10.00-20.00 

15.00-30.00 

6.00-12.00 

B.00-12.00 

16.00-20.00 

35.00-50.00 

35,00-50.00 

25.00 

20.00 

25.00 

25.00-35.00 

25.00 

20.00 

30.00-40.00 

15.00 

20.00-22.00 

25.00 

20.00-25.00 

25.00 

25.00 

25.00 

14.00 

10.00-20.00 

329 
Table 3-Pounds of native seed sold in 1996 by five Utah seed companies. 

Grass species 

Pounds of 

seed Forb species 

Western yarrow 

Common sunflower 

Blue flax 

Pounds of 

seed Shrub species 

Pounds of 

seed (bulk) 

Thickspike wheatgrass 

Western wheatgrass 

Basin wildrye 

Mountain brome 

Snake River wheatgrass 

Slender wheatgrass 

27,305 

23,616 

22,522 

19,202 

15,000 

14,400 

Rocky Mountain bee plant 

Lupine (several species) 

Palmer penstemon 

8,443 

5,900 

3,965 

3,200 

2,686 

2,010 

Wyoming big sagebrushc 

Fourwing saltbush 

Mountain big sagebrushc 

Basin big sagebrushc 

Shad scale saltbush 

White-stemmed rubber 

120,000 

76,350 

22,522 

20,230 

14,250 

11,765 

Streambank wheatgrass 

Indian ricegrass 

California poppy 

Desert globe mallow 

Arrowleaf balsamroot 

Utah sweetvetch 

Showy goldeneye 

Munro globemallow 

rabbitbrushc 

Antelope bitterbrush 

Winterfat 

Mountain rubber rabbitbrushc 

Gardner saltbush 

Douglas rabbitbrush 

Woods rose 

Sheep fescue 

Bluebunch wheatgrass 

Bottlebrush squirretail 

Green needlegrass 

Sherman big bluegrass 

Sideoats grama 

11,850 

11,555 

9,950 

9,552 

7,865 

2,865 

2,500 

2,000 

2,000 

6,324 

Rocky Mountain Penstemon 

Sweet anise 

2,000 

900 

625 

597 

530 

500 

500 

490 

Skunkbush sumac 

Green ephedra 

6,047 

5,445 

5,350 

4,200 

2,200 

2,200 

1,820 

1,605 

1,600 

1,255 

Alkali sacaton 25 othersb (2 - 410) 

14 othersa (10-1,202) 

Total 188,506 

Grand Total 

3,081 Low rabbitbrush 

Nevada ephedra 

26 othersd (10- 955) 

35,427 

10,229 

307,068 

531,001 

aSandberg bluegrass, sand dropseed, Idaho fescue, meadow foxtail, galleta, blue grama, tufted hairgrass, prairie June grass, needle-and thread grass, Letterman 

needlegrass, redtop, purple three-awn, alpine timothy, beardless wildrye. 

bSlueleaf aster, Engleman aster, pacific aster, cutleaf balsam root, columbine, cow parsnip, erigeron species, eriogonum species, farewell-to-spring, gaillardia, sticky 

geranium, gilia, gooseberryleaf globe mallow, one-flower helianthella, Porter ligusticum, Louisiana sagewort, desert marigold, mules ear wyethia, Indian paintbrush, 

firecracker penstemon, Rydberg penstemon, thickleaf penstemon, Wasatch penstemon, Iseland poppy. 

cSubspecies. 

dOesert bitterbrush, roundleaf buffaloberry silver buffaloberry, chokecherry, Stansbury cliffrose, golden current, wax current, redosier dogwood, blue elderberry, red 

elderberry, Wyeth eriogonum, black greasewood, spiny hopsage, curlleaf mountain mahogany, true mountain mahogany, black sagebrush, silver sagebrush, fringed sage, 

sand sage, quail saltbush, mat saltbush, Saskatoon serviceberry, Utah serviceberry, mountain snowberry, Rocky Mountain sumac. 

Barnes, D. K; Sheaffer, C. C.1985. Alfalfa. In: Heath, M. E.; Barnes, 

R F.; Metcalf, D. S., eds. Forages, the science of grassland 

agriculture, 4th edition. Ames, IA: Iowa State University Press: 

89-97. 

Carlson, J. R; McArthur, E. D., eds. 1985. Symposium: range plant 

improvement. In: Proceedings, selected papers presented at the 

38th Annual Meeting of the Society for Range Management 1985 

February 11-15; Salt Lake City, UT. Denver, CO: Society for 

Range Management: 107-220. 

Jordan, W. R, III.; Gilpin, M. E.; Aber, J. D., eds. 1987. Restoration 

ecology, a synthetic approach to ecological research. Cambridge, 

UK: Cambridge University Press. 342 p. 

McArthur, E. D. 1988. New plant development for range management. In: Tueller, P. T., ed. Vegetation science applications for 

rangeland analysis and management. Dordrecht, Netherlands: 

Kluwer Academic Publishers: 81-112. 

Meyer, S. E.; Kitchen, S. G. 1995. First the seed: a restorationist's 

perspective. Hortus Northwest 6 (2): 4-8, 42-43. 

Monsen, S. B. 1987. Shrub selections for pinyon-juniper plantings. 

In: Everett, R L., compo Proceedings-pinyon-juniper conference; 1986 January 13-16; Reno, NV. Ogden, UT: Gen. Tech. Rep. 

INT-215, U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 326-329. 

Monsen, S. B.; McArthur, E. D. 1995. Implications of early Intermountain range and watershed restoration practices. In: Roundy, 

B. A; McArthur, E. D.; Haley, J. S.; Mann, D. K, comps. Proceedings: wildland shrub and arid land restoration symposium; 1993 

October 19-21; Las Vegas, NV. Ogden, UT: Gen. Tech. Rep. INTGTR-315. U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 16-25. 

Monsen, S. B.; Stevens, R, eds. In press. Restoring western range 

and wildlands. Ogden, UT: Gen. Tech. Rep. RMRS-GTR-xxx. U.S. 

Department of Agriculture, Forest Service, Rocky Mountain 

Research Station. 

330 

Plummer, A P.; Christensen, D. R; Monsen, S. B. 1968. Restoring 

big game range in Utah. Publication 68-3. Salt Lake City, UT: 

Utah Division of Fish and Game. 183 p. 

Plummer, M.1984. Considerations in selecting chenopod species for 

range seedings. In: Tiedemann, A R.; McArthur, E. D.; Stutz, 

H. C.; Stevens, R: Johnson, K L., comps. 1983 May 2-6; Provo, 

UT. Ogden, UT: Gen. Tech. Rep. INT-l72. U.S. Department of 

Agriculture, Forest Service, Intermountain Forest and Range 

Experiment Station: 183-186. 

Richards, R T.; Chambers, J. C.; Ross, C. 1998. Use of native 

plants on federal lands: policy and practice. Journal of Range 

Management. 51: 625-632. 

Roundy, B. A 1996. Revegetation of rangelands for wildlife. In: 

Krausman, ed. Denver, CO: Society for Range Management: 

355-368. 

Roundy, B. A; McArthur, E. D.; Haley, J. S.; Mann, D. K comps. 

1995. Proceedings: wildland shrub and arid land restoration 

symposium. 1993 October 19-21; Las Vegas, NV. Ogden, UT: Gen. 

Tech. Rep. INT-GTR-315. U.S. Department of Agriculture , Forest 

Service, Intermountain Research Station. 384 p. 

Rumbaugh, M. D.; Townsend, C. E. 1985. Range legume selection 

and breeding in North America. In: Carlson, J. R; McArthur, 

E. D., eds. Symposium: range plant improvement. 1985 February 

11-15; Salt Lake City, UT. Denver, CO: Proceedings, selected 

papers presented at the 38th Annual Meeting of the Society for 

Range Management: 137-147. 

Young, S. 1995. Alternative germplasm release procedures for 

producing certified seed. Seed World 133 (8): 14-15. 

Young, S.; Kitchen, S.; Armstrong, J. 1995. AOSCA approves certification guidelines for wild land collected seed. Seed World 133 

(1): 20-21. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Species Compatibility and Successional 

Processes Affecting Seeding of PinyonJuniper Types 

Scott C. Walker 

Abstract-Introduced perennial grasses have long been used in 

rangeland revegetation efforts. These species have gained dominance in some communities. The competitiveness of these species 

have reduced native vegetative components. Through evaluation of 

long term ecological studies, the competitiveness of some introduced 

seeded species have become apparent. -Our findings reveal that 

differences in species composition can be attributed to the competition of the seeded introduced species. 

When restoring areas that have been inundated by 

pinyon-juniper trees, seeding is often necessary where 

desirable understory species are absent or too sparse to 

respond to treatment. Seeding efforts involved with pinyonjuniper treatment have been directed toward increasing 

forage production for livestock and restoring plant communities and wildlife habitat. 

Seed mixtures have included various introduced and native 

grasses, forbs, and shrubs (Stevens 1983). Over the past 30 

to 40 years, introduced grass species have dominated most 

seed mixtures. These grasses were selected for a number of 

reasons incl uding availabili ty of seed, ease of establishment, 

forage production, and soil stabilization characteristics. 

The compatibility of these exotic species with native herbs 

and shrubs is now becoming apparent through long term 

ecological studies. Many exotic species have competitive 

and aggressive establishment, and consequently have a 

direct adverse affect on native species and communities. 

These affects are often detrimental and have an adverse 

impact on natural functioning plant communities and ecosystems. Competition for limited resources may determine 

the presence, absence, or abundance of species within a 

community as well as their spatial arrangement (Pyke and 

Archer 1991). Mter reviewing research investigating competition in semiarid plant communities, Fowler (1986) concluded that competition does occur in these systems, involves different species, and is an important determinant of 

community structure. Rapid changes in plant communities 

occur on disturbed areas, such as chained and seeded 

pinyon-juniper sites (Stevens 1986; 1987). 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Scott C. Walker is a ResearchIWildlife Biologist, Division of Wildlife 

Resources, Great Basin Research Center, Ephraim, UT 84627. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Techniques have been developed that effectively remove 

trees while retaining the understory and creating the necessary seedbed. Plant research and development has resulted 

in considerable progress in improving availability of native 

grass, forb and shrub seed and in improving their establishment. These plant materials allow us to now go beyond 

revegetation to restoration. Ideally, ecologically speaking, 

our effort now is to restore sites and help return them back 

to a situation where natural processes can function. 

Effects of Introduced Grasses __ 

This paper will address the ideas of species compatibility. 

It is important to consider the effect that seeding has on 

the natural recovery of species that are released when an 

area is treated, and the influences of seeding exotics with 

natives. The following case studies demonstrate effects of 

introduced grasses on native and other seeded species. 

Case Study 1-Gambel Oak Control by 

Intermediate Wheatgrass, Smooth Brome 

and Fairway Crested Wheatgrass 

(Plummer and Others 1970) 

Large areas of Gambel oak were burned to remove overstory oak stems. These areas were then seeded to a mixture 

of intermediate wheatgrass (Thinopyron intermedium), 

smooth brome (Bromus inermis), and Fairway crested wheatgrass (Agropyron cristatum) in equal amounts at a total 

seeding rate of 12-15 lb per acre. A like area that burned 

was not seeded with the grass association. 

Figure 1 shows the accumulative height of oak after 

15 years on the area where, Fairway crested wheatgrass, 

intermediate wheatgrass and smooth brome were established as an understory after a burn. This is contrasted 

with an adjacent similar area where oak was burned but 

where no seeding occurred. The accumulated growth of oak 

on sites that were seeded has been maintained at an average 

height of about 40 inches and has remained open; whereas 

on nonseeded sites the oak has grown to an average height 

of 105 inches, and the clumps have again become impenetrable thickets. When well established, the seeded grasses 

have restricted the height regrowth of oak on treated sites 

by more than 60 percent. 

Findings of this study were that, "After 14 years, it continues to be confirmed that competitive herbs can be seeded 

and established for controlling Gambel oak thickets, as 

well as thickets of other shrubs. Intermediate wheatgrass 

and smooth brome (two sod formers), and Fairway crested 

331 
120 I----~-- ---------------------.------ - -- ---l 

100 l_~ithou~ exotic gr: association _I 

(j) I I Q) I "fi 80 --+-----~------- ---~---~~-------j 

5 i 

~ I ~ 60 - -~---------- ----------~----~-l 

b I t 40 ~ ------ ~--==j(-----)t..:::::...K-~?=-~-~-~~--1 

~ /)Ir 4E- With exotic grass association I 

20 ----- ---------------------j 

I 

I I 

o -t-~T--r--r-~T-,---~---,------r--T~~r-i --I 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 

Years Following Treatment 

Figure 1-Mean accumulative height of Gambel oak 

plants in treatment areas with and without seeded 

exotic grass association. 

w heatgrass have been found to be particularly useful for this 

purpose." Also, "Grazing by deer, as well as by livestock, 

appears to keep brush from growing beyond animal's reach, 

but most important is the competition from the established 

understory plants." 

This study demonstrates that species interaction and 

competition can be beneficial depending on the desired 

outcome and management objective. It also shows how 

very competitive some introduced species can be. There 

was no information in the study to indicate how other 

plant species on the study area were affected. It is reasonable to assume that if these grasses were able to effectually 

reduce oak regrowth through competition for resources, 

then other understory species were likely adversely affected. 

Case Study 2-The Competitive Influence 

of Seeded Smooth Brome (Bromus 

Inermis) and Intermediate Wheatgrass 

(Thinopyron Intermedium) Within AspenMountain Brush Communities of Central 

Utah (Monsen And Others 1996) 

Ecological relationships of smooth brome and intermediate wheatgrass with native species were investigated through 

comparison of seeded and nonseeded sites in aspen-mountain brush communities, on the Great Basin Research Area, 

Manti-La Sal National Forest. These sites were adjacent to 

each other, and vegetatively comparable prior to seeding. 

Within a 40-year period, the two sod-forming seeded grasses 

gained dominance and reduced native herbs and shrubs. 

Both introduced grasses are commonly planted to stabilize 

wildlands, but they are proving to be noncompatible with 

most native species and ultimately dominate seeded sites. 

All lifeform groups (introduced grasses, native grasses, 

native perennial broadleaf herbs, and shrubs) showed a 

statistically significant difference in the percent ground 

cover values between the seeded and nonseeded areas. 

332 

Fourty years after seeding the seeded areas showed a mean 

percent ground cover for introduced grasses was 33 percent, 

native grasses 1 percent, native perennial broadleaf herbs 

11 percent, and shrubs 15 percent. In the nonseeded areas 

the mean percent cover for introduced grasses was 4 percent, 

native grasses was 17 percent, native perennial broadleaf 

herbs 21 percent, and shrubs 41 percent (fig. 2). 

One hundred-nine species were encountered within the 

study sites. Of all species present, 86 were found in the 

seeded areas and 82 in the nonseeded areas, with 61 species 

common to both areas. Results of Sorensen's index of similarity, (Sorensen 1948) for all areas combined within a 

treatment, shows only a 41 percent similarity of species 

between the two treatments. This indicates the dissimilarity 

ofthe species composition between the two treatments, even 

though the number of species in each area is nearly equal. 

Prevalent species ranking by frequency value shows considerable difference between seeded and nonseeded areas 

(taole 1). Smooth brome, intermediate wheatgrass and mountain big sagebrush (Artemisia tridentata vaseyana) were the 

most prevalent species in the seeded areas, while mountain 

snowberry (Symphoricarpos oreophilus), mountain big 

sagebrush and bluebunch wheatgrass (Pseudoroegneria 

spicata) were the most prevalent in the nonseeded areas. 

Considerable difference in forb species occurrences and 

numbers were evident between treatments. The numbers of 

forb species between treatments were nearly equal with 

58 in the seeded and 57 in the nonseeded area of these 

species 40 were common to both treatments. Native forb 

species accounted for a greater percent of the ground cover 

in the nonseeded than in the seeded area (fig. 2). This would 

indicate that native perennial forbs are doing better in the 

nonseeded area and did not fair well growing in combination 

with the exotic grasses 

Considerable variation in summed frequency was evident 

between seeded and nonseeded areas (fig. 3). In the seeded 

50 ~-----.. --

Species Groups 

a: 

w 

> o 

u 

0 30 z 

::> 

o 

a: 

(!) 

~ 20 w 

u 

a: 

w 

Il. 

10 

o 

• Int. Per. Grass • Nat. Per. Grass 

111 Shrub D Nat. Per. Forbs 

S NS 

S=SEEDED 

NS=NONSEEDED 

S NS S NS 

TREATMENTS 

Figure 2-Percent ground cover of lifeform groups 

for seeded and nonseeded areas, 40 years after 

seeding. *Within species groups, columns with different letters indicate significant differences (p < 0.05). 

-]---

S NS 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 1-Ranking of most prevalent species for area seeded with 

introduced grasses and nonseeded areas. 

Seeded Area Nonseeded Area 

1. Bromus inermis 1. Symphoricarpos oreophilus 

2. Thinopyron intermedium 2. Artemisia tridentata 

3. Artemisia tridentata 3. Pseudoroegneria spicata 

4. Lupinus sericeus 4. Bromus carinatus 

5. Symphoricarpos oreophilus 5. Aster chilensis 

6. Vicia americana 6. Astragalus conval/arius 

7. Agoseris glauca 7. Vicia americana 

B. Aster chilensis B. Eriogonum umbel/a tum 

9. Agropyron crista tum 9. Stel/aria jamesiana 

10. Taraxacum officinale 10. Agropyron trachycaulum 

area the introduced grasses were significantly more frequent than in the nonseeded area. Native grasses and 

shrubs were significantly more frequent in the nonseeded 

area than in the seeded areas. Though native forbs showed 

no significant difference between treatments as a group, 

there are difference in the species composition between 

treatments. 

Species, cover, composition, and frequency differences 

between aspen-mountain brush communities seeded to 

smooth brome and intermediate wheatgrass in the 1950's 

and adjacent nonseeded areas, demonstrate the competitiveness and adverse influence of these seeded grasses on 

native species. Seeded and nonseeded areas were similar at 

time of seeding. Grazing pressure on these areas has been 

the same. Conclusions were similar to those of Rosentreter 

(1994), Davis and Harper (1990), and Walker and others 

(1995), in that differences in species composition can be 

attributed to the competition of the seeded species. Native 

grasses, forbs, and shrub species diversity, frequency, and 

cover are higher in the nonseeded areas. Few native 

140 -,------- ---~----- --------------,--,-----------, 

>-

() 

z 

UJ 

Species Groups 

• Int. Per. Grass • Nat. Per. Grass 

120 III Shrub C3 Nat. Per. Forbs 

100T--~------_+------~---~--~ 

5 80T-~~---~-------T_------r---L;"dLC UJ 

a: 

LL 

fil 60 ~ 

~ 

:::J 

CJ) 

40 

20 

o S NS 

S=SEEDED 

NS=NONSEEDED 

S NS S NS 

TREATMENTS 

Figure 3-Summed frequency of lifeform groups for 

seeded and nonseeded areas, 40 years after seeding. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

S NS 

25 ................................................................................................................ .. 

I ;. ........ ii. ........................................................................... ;~ ......................... . 

~ 16.5 

f15 ........... ·· .. ·· ........ ···· .. ·· .... ·· .. · .. ·p; .. ··• .. •• .. ~· .... A .. ··•··· ..................................... . 

Q) 12.2 11. 

o A 16 1 ........................ :1"'" ..................................................................... ~ ....... .. 

I ~ 

5 ··· .. ··t6~·~·~·~·~·~·~·~~~=~~~~~~!~~·~·~·~·~·~·~·~·~~~~~~~·~~·16:·:·~·;:;"- .. ~~········· 

o 64 67 72 77 82 

Year 

1--- Introduced Grasses -+-. Native Grasses 

Figure 4-Average density of introduced and native 

grasses within the ungrazed treatment. Values with the 

same letter are not significantly different (p < 0.05). 

87 

grasses, forbs, or shrubs within the aspen-mountain brush 

communities in central Utah can compete with intermediate 

wheatgrass and smooth brome. These introduced grasses 

are proving to be noncompatible with most native species 

and ultimately dominate seeded sites. The concomitant loss 

of species diversity diminishes resource values. 

Case Study 3-lnteraction Between Native 

and Seeded Introduced Grasses Through 

23 Years Following Chaining and Seeding 

of Juniper-Pinyon Woodlands (Walker 

And Others 1995) 

Threejuniper-pinyon woodland sites in central Utah were 

evaluated over 23 years following chaining and seeding of 

introduced grasses under grazed and nongrazed conditions. 

The density and production of herbaceous species was 

measured at intervals for 23 years in both the grazed and 

nongrazed treatments. In 1964, three to five years following initial treatment, introduced grasses had a five times 

greater density than the native grasses in the ungrazed 

areas (fig. 4). The density trend of the introduced grasses 

has continued to increase through 1987, while keeping the 

native grasses somewhat suppressed. 

Under grazing pressure the introduced grasses have not 

increased in density at the same rate as in the ungrazed 

treatment. In the grazed treatment the introduced grasses 

have generally maintained at least twice the density as the 

natives (fig. 5). In the grazed treatment the introduced 

grasses are dominated by Fairway crested wheatgrass and 

intermediate wheatgrass. In the ungrazed treatment the 

introduced grasses are dominated by smooth brome and 

Fairway crested wheatgrass (table 2). 

There has been a dramatic shift in the composition of 

the native species following seeding in both the grazed and 

ungrazed treatments. In 1964, both treatments supported 

a good compliment of a number of native grasses. Bottlebrush squirreltail (Sitanion hystrix), Indian ricegrass 

(Oryzopsis hymenoides), and bluebunch wheatgrass was 

333 
25 --------------------------------------------------------------------------------------------------------------------

JB Q) A E 2 -------18"-------------------------------------------------------------------------------------------------------- g- . .> 

~ 15 -------------- --------------------------------.. -.----.--..•. -.•...• ·-···-··-··-_··_-C--_·---·········,:.-S··_··_· 

c C C 119 ~c ~ 10.5 10.7 ., ,11.5 ffi 1 _.---•••. _-----.• ----. ····ei-·····_··_···- --....... --.. -..... -.-... --.--... --... -.-... --.. ;~ ...... -.. --........ . Q).6 a " ~ a a 54-' 

5 ·······~i·~-~·~·~·.:·;·;W~::::::::.:::::t:(:·:·:.::.:;::.·;.W ... u_-_~r.:-:~ •••••••••••••••••••••••••• _. 

O~--r-----~------~------~----~------~--~ 64 67 72 77 82 

Year 

1--- Introduced Grasses -+-. Native Grasses 

Figure 5-Average density of introduced and native 

grasses within the grazed treatment. Values with the 

same letter are not significantly different (p < 0.05). 

87 

well distributed throughout the areas (table 3). In 1987 

the native grass composition shifted to, and is dominated by, 

a less productive sandberg bluegrass (Poa secunda) and 

western wheatgrass (A. smithii). The 1987 native grass 

component in the grazed treatment is comprised almost 

entirely (99 percent) of these two species (table 3). 

Bottlebrush squirreltail and needle-and-thread (Stipa 

comata) responded favorably to removal of the juniperpinyon, but succumbed to the more competitive species 

once they became established. Indian ricegrass and 

bluebunch wheatgrass are perennials that would be expected to respond favorably to tree removal. They both did, 

however, as the introduced species became firmly established, they were not able to compete with the aggressive 

exotics, with and without grazing. Western wheatgrass 

was able to compete somewhat with the introduced species, 

with or without grazing. Sandberg bluegrass, an opportunist, did well growing in association with western wheatgrass and the introduced species. 

Table 2-Rank of introduced grasses by frequency and by density for grazed and ungrazed treatments. The rank is based on the 

334 

average of three study areas, in the first data collection year (1964) and in the last data collection year (1987), showing 

species composition changes 

Rank by 

Species frequency 

Ungrazed 1964 

Intermediate wheatgrass' 1 

Fairway wheatgrass" 2 

Smooth brome 3 

Orchard grass 4 

Russian wildrye 5 

Bulbous bluegrass 6 

Ungrazed 1987 

Fairway wheatgrass" 1 

Intermediate wheatgrass' 2 

Russian wildrye 3 

Smooth brome 4 

Grazed 1964 

Fairway wheatgrass" 1 

Intermediate wheatgrass' 2 

Smooth brome 3 

Bulbous bluegrass 4 

Russian wild rye 5 

Orchard grass 6 

Grazed 1987 

Fairway wheatgrass" 1 

Intermediate wheatgrass' 2 

Russian wild rye 3 

'Combination of intermediate and pubescent wheatgrass. 

"Combination of fairway and standard wheatgrass. 

Frequency of 

occurrence 

15 

10 

5 

4 

4 

3 

15 

11 

8 

5 

15 

14 

10 

4 

4 

3 

10 

7 

6 

Rank by Density'" 

density (per hal 

2 1,990 

1 5,779 

4 565 

3 684 

6 24 

5 24 ---

9,066 

2 5,913 

3 402 

4 24 

11,745 

18,084 

1 5,360 

2 1,918 

3 1,091 

5 62 

6 29 

4 67 

8,527 

1 10,635 

2 646 

3 178 

11,459 

'''Number of individual culms with rhizomatous species. Number of individual plants with bunchgrasses. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 3-Rank of native grasses by frequency and by density for grazed and ungrazed treatments in the first data collection year 

(1964) and in the last data collection year (1987), showing species composition changes 

Rank by Frequency of Rank by Density'" 

Species frequency occurrence density (per ha) 

Ungrazed 1964 

Bottlebrush squirreltail 1 15 1 837 

Indian ricegrass 2 11 2 598 

Bluebunch wheatgrass 3 9 3 378 

Western wheatgrass 4 4 4 148 

Sandberg bluegrass 5 4 5 29 

Needle-and-thread 6 2 6 19 

2,009 

Ungrazed 1987 

Sandberg bluegrass 1 10 1 2,29 

Western wheatgrass 2 9 2 1,512 

Indian ricegrass 3 3 3 24 

Bluebunch wheatgrass 4 2 4 19 

Bottlebrush squirreltail 5 5 5 ---

3,856 

Grazed 1964 

Bottlebrush squirreltail 1 15 1 723 

Indian ricegrass 2 13 2 698 

Sandberg bluegrass 3 5 4 72 

Bluebunch wheatgrass 4 5 5 48 

Western wheatgrass 5 2 3 101 

Needle-and-thread 6 6 5 

1,647 

Grazed 1987 

Sandberg bluegrass 1 10 9,989 

Western wheatgrass 2 10 2 4,758 

Indian ricegrass 3 5 3 75 

Bluebunch wheatgrass 4 5 4 32 

Needle-and-thread 5 1 5 22 

Bottlebrush squirreltail 6 1 6 11 ---

14,887 

'Number of individual culms with rhizomatous species. Number of individual plants with bunchgrasses. 

Results show that after 23 years following the introduction of exotic grass species, the communities, though changing in density and cover, have not yet stabilized in plant 

dominance. The introduced grasses are increasing in density, cover, and production at a greater rate than are the 

native grasses that have shown a reduction in diversity. 

Case Study 4-Long-Term Harmful Effects 

of Crested Wheatgrass on Great Plains 

Grassland Ecosystems (Lesica and 

Deluca 1996) 

Lesica and DeLuca (1996) have done a comprehensive 

review of literature related to crested wheatgrass effects 

on Great Plains ecosystems. In summary: 

Invasions by exotic plants are occurring at an increasing 

rate and are considered a serious threat to both agricultural 

systems as well as native communities (Drake and others 

1989). Not only are exotics invading large areas, exotics 

have and are being planted extensively. Crested wheatgrass 

(A. cristatum and A. desertorum) is the most commonly 

planted exotic grass in western North America. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Crested wheatgrass has many desirable characteristics. 

These include, good forage yields, ease of establishment, 

good nutritional values, and it resists invasion by weeds. 

Although crested wheatgrass has desirable characteristics 

there are several often overlooked characteristics that 

may create a significant long-term decline in biological 

diversity and soil resource sustainability. 

It is not uncommon to have considerable soil loss in crested 

wheatgrass stands. The strong competitiveness of crested 

wheatgrass creates a situation that results in high amounts 

of exposed soil. Grasslands with more exposed soil experiences higher rates of erosion (Wilson 1989; Dormaar and 

others 1995; McWilliams and Van Cleave 1960). 

Perhaps a more serious effect on soil properties than the 

potential for increased soil erosion is the effect crested 

wheatgrass has on biochemical soil quality. Crested wheatgrass has a higher above-ground productivity than many 

native grasses. However, the below-ground biomass in the 

surface horizon is significantly lower (Dormaar and others 

1995; Retente and others 1989; Smoliak and Dormaar 1985; 

Smoliak and others 1967). This lower below-ground biomass 

in crested wheatgrass reflects a reduction in both root 

detritus and root exudates that would otherwise be available 

335 
for microbial use in the formation of soil organic matter. Ai:, 

a result, below-ground biomass under stands of crested 

wheatgrass has a higher carbon to nitrogen ratio than native 

grass species and only supplies about half as much organic 

N to the soil as does native grasslands (Biondini and others 

1988; Klein and others 1987, 1988; Redente and others 

1989). The small quantity and lower quality of organic 

matter in the upper soil horizons under stands of crested 

wheatgrass also results in a lower energy input to these soils 

as compared to native ranges (Dormaar and others 1978) 

and alters physical and biochemical processes in the soil. 

Stands of crested wheatgrass are associated with higher 

bulk density, fewer water stable aggregates, and lower 

levels of organic matter and nitrogen when compared to 

native grasses (Biondini and others 1988; Dormaar and 

others 1978; 1995; McHenry and Newell 1947; Redente and 

others 1989; Smoliak and others 1967Y. Crested wheatgrass 

provides the soil with a relatively high concentration of 

carbohydrates and little organic nitrogen (that is, the socalled "priming effect") as quantities of readily degraded 

carbohydrates in the presence of limited nitrogen often 

result in a net demand on soil organic nitrogen (DeLuca and 

Keeney 1993; Jansson and Persson 1982; Mortensen 1963). 

It has been suggested that these alterations to soil quality 

may prevent native species from invading crested wheatgrass monocultures (Klein and others 1988). 

We presently lack the knowledge to know the long-term 

effects of crested wheatgrass. However, there is a growing 

body of knowledge that suggests that crested wheatgrass 

alters the environment in many undesirable ways. Further 

research into the changes in soils and plant and animal 

diversity associated with crested wheatgrass in the Great 

Plains as well as the Intermountain west are needed to 

assess its impact. Nonetheless, the continued conversion of 

native range and planting of crested wheatgrass in large 

stands as mono cultures or other exotic species seems ill 

advised. 

Discussion --------------------------------- These four case studies help us understand that plant 

communities are continually changing in plant composition, 

density, and cover due to the effect directly caused by seeded 

species, precipitation cycles, and impacts from grazing or 

other disturbances. Introduced grasses have became more 

dominant in the communities, especially in the absence of 

grazing. The competitiveness of these grasses have caused 

a decline in native vegetation, reducing desirable species 

and changing plant composition. The data indicate that 

most native grasses do not appear to compete well with the 

species that were introduced. These results are Similar to 

those of Bock and others (1986) who reported that stands of 

exotic grasses support significantly lower variety and abundance of indigenous grasses. Davis and Harper (1990) report 

that planting a mixture of introduced and native species 

may produce artificial plant associations in which species 

mayor may not be fully compatible with each other; and that 

it is difficult to maintain a stand of specified composition 

because each species responds differently to natural and 

imposed environmental factors that affect competitiveness. 

336 

There is an obvious shift in composition over time, the 

exotics are favored generally at the expense of native communities. Trends indicate that over a 30 or 40 year period 

of time introduced grasses are going to increase until 

they become dominant. For wildlife habitat, for biological 

diversity and for ecological integrity this scenario is not 

acceptable. 

Acknowledgments 

Funds were provided through Federal Aid in Wildlife 

Restoration Project W82R, Studies 4,5, and 7; and Rocky 

Mountain Research Station, Forest Service, U.S. Department of Agriculture, Provo, Utah. 

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effects of planting African lovegrass in Arizona. Nat. Geogr. Res. 

2: 456-463. 

Davis, J. N., Harper, K. T. 1990. Weedy annuals and establishment 

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changes associated with seeded stands of crested wheatgrass in 

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cristatum (L.) Gaertn.) And Russian wild rye (Elymus junceus 

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wheatgrass and native grass mixtures seeded on rangeland in 

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ed. Proceedings of the fifth International Rangeland Congress. 

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558-571. 

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U.S. Department of Agriculture, Forest Service, Intermountain 

Research Station: 278-285. 

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black and low sagebrush, and pinyon-juniper communities. In: 

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Experiment Station: 78-82. 

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23 years following chaining of juniper-pinyon woodlands. In: 

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Mann, David K, comps. 1995. Proceedings: wildland shrub and 

arid land restoration symposium; 1993 October 19-21; Las Vegas, 

NV. Gen Tech. Rep. INT-GTR-315. Ogden, UT: U.S. Department 

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introduced for revegetation. Landscape Urban Plann. 17: 113-119. 

337 
Native Plant Solutions for Conservation 

Problems 

Mark Majerus 

Susan Winslow 

Joe Scianna 

Abstract-The Bridger Plant Materials Center in Montana focuses 

on native species selection and establishment techniques for revegetation of rangeland, mineland, and other disturbed areas of the 

West. Work is carried out as a cooperative among several government and private organizations. 

The Bridger Plant Materials Center (PMC) was established in 1959 by the USDA Natural Resources Conservation Service (NRCS) to help solve conservation problems in 

Montana and Wyoming. The land and facilities are owned by 

a nonprofit corporation consisting of all conservation districts in Montana and Wyoming and in turn leased to USDANRCS. Projects have focused on native species selection and 

establishment techniques for revegetation of rangeland, 

mineland, highly erodible sites, acid/heavy metal affected 

lands, wildlife cover/food, xeriscaping, and saline-affected 

soils. Research on native trees and shrubs has focused on the 

identification and testing of su perior ecotypes for windbreak 

and shelterbelt applications in the Great Plains. In 1986, a 

cooperative agreement with the National Park Service was 

initiated to assist with the identification, collection, propagation, processing, and culture of indigenous species for 

revegetating roadsides. Assistance began in 1994 emphasizing the identification, propagation, and establishment of 

culturally significant plants of Native American tribes. As 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedin~s: 

ecology and management of pinyon-juniper communities within the InterlOr 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Mark Majerus, Susan Winslow, and Joe Scianna are with ~he Brid~er 

Plant Materials Center, USDA Natural Resources ConservatlOn Servlce, 

Route 2, Box 1189, Bridger, MT 59014 

338 

a service to the Montana Natural Heritage Program, germination and propagation techniques are being developed for 

"threatened" Penstemon lemhiensis and to the U.S. Fish and 

Wildlife Service for seed increase of "sensitive" Gaura 

neomexicana ssp. coloradensis. 

Native plant species are collected from throughout 

Montana and Wyoming and evaluated at the Bridger Plant 

Materials Center or other appropriate remote sites. The 

seed of superior accessions (collections) is increased and 

then established in replicated plots. The su perior material is 

increased and made available for field planting throughout 

Montana and Wyoming on private and public lands. These 

plantings are established under actual use situations and 

compared to commercially available germplasm for a particular conservation use. Once a plant is proven superior, 

seed is made available to growers for commercial prod uction 

and sale. The Bridger PMC presently utilizes alternative 

release mechanisms, which ensure genetic integrity, while 

allowing plant materials to be released with a limited amount 

of testing. These alternatives are, from least tested to most 

tested: "source identified"-seed harvested from a native 

stand or collected and grown under cultivation; "selected"-

germplasm that has genetic superiority or distinctive traits; 

"tested"-material that has been through multiple years, 

multiple site testing which statistically validates superior 

traits' and "cultivar"-material that has had purposeful genetic ~anipulation or extensive replicated and field testing. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Evaluation of Plant Materials for Use in 

Reclamation of Disturbed Rangelands in 

Semi-Arid Areas of Northern Utah 

Melissa V. Britton 

Val Jo Anderson 

R. D. Horrocks 

Howard Horton 

Abstract-Reclamation of degraded and disturbed rangelands in 

the arid west continues to be both desirable and difficult. At their 

best, reclamation practices and efforts often fail in their objectives 

due to harsh environmental conditions that tend to be difficult to 

predict. Development of species adapted to these harsh conditions 

improve reclamation success rates. The objective of this study was 

to test and select species that are adapted to two range site types in 

northern Utah. Between 20 and 24 species were used in replicated 

adaptability trials at two sites, sagebrush (Artemisia spp.)/grass 

and greasewood (Sarcobatus uermiculatus), located immediately 

southwest of Utah Lake in Northern Utah. Several species of both 

native and introduced grasses were evaluated as adapted to these 

sites, respectively. Alkar tall wheatgrass (Elymus elongatus) preformed well at the greasewood site, while crested wheatgrass 

(Agropyron crisfatum) varieties established well at the sagebrush/ 

grass site. A larger group of species performed well at the greasewood site than at the sagebrush/grass site. 

Reclamation and revegetation of arid and semiarid rangelands are difficult processes complicated by severe environmental conditions. Natural recruitment in areas of low 

precipitation is limited to wetter years (Roundy and Call 

1988; Allen 1995). Developme'nt of improved plant varieties 

which are better adapted to dry areas can increase success 

of rangeland revegetation (Asay and others 1985; Munda 

and Smith 1995). 

Two vegetation types found in arid and semiarid areas of 

the Great Basin are sagebrush (Artemisia spp.)/grass and 

greasewood (Sarcobatus uermiculatus). Sagebrush/grass 

types have a long history of reclamation (Young and others 

1979). Seeding strictly with native species met with little 

success, and use of introduced species became necessary 

(Young and others 1979). Crested wheatgrass (Agropyron 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Melissa V. Britton is a Graduate Student at Brigham Young University. 

Val Jo Anderson is a Professor of range ecology at Brigham Young University, 

Provo, UT 84602. R. D. Horrocks is a Professor of agronomy at Brigham Young 

University, Provo, UT 84602. Howard Horton is a scientist with the USDA 

ARS in Logan, UT 84322. ' 

USDA Forest Service Proceedings RMRS-P-9. 1999 

cristatum) was one of the first introduced species successfully tested and used in adaptability trials. Kellar (1979), in 

a review of species selection and seeding methods for sagebrush/grass sites, stated that crested wheatgrass has been 

the most important grass in revegetating these sites. Other 

important sagebrush/grass species included intermediate 

and pubescent wheatgrasses (Agropyron intermedium), 

Siberian wheatgrass (Agropyron cristatum), Russian wildrye 

(Elymus junceus), and dryland alfalfa (Medicago sativa) 

(Kellar 1979). 

Seedling establishment has proven difficult on greasewood sites, because of large amounts of salts in the soil 

(Forsburg 1953; Rollins and others 1968; Malcolm 1969; 

Sandoval and Gould 1978; Roundy and others 1983; USDA 

1984; Roundy 1985). High concentration of salts can be toxic 

to plants, causing nutritional imbalances (Rollins and others 1968; Maas 1986), and reduced matric and osmotic 

potential of the soil (Sandoval and Gould 1978; Roundy 

1985). In some greasewood sites the soils are sodic rather 

than saline (high salts but no excess of sodium). Sodic soils 

have a sodium adsorption ratio (SAR) greater than 13 and 

usually have a basic pH (Sandoval and Gould 1978; Jurinak 

1981). Excessive sodium creates dispersed clay colloids in 

the soil which reduces infiltration of water into the soil 

(Rollins and others 1968; Sandoval and Gould 1978). Tall 

wheatgrass and basin wildrye (Elymus cinereus) varieties 

are among the few species which have proven to be successful on greasewood sites (Forsburg 1953; Fleck 1967; Rollins 

and others 1968; Malcolm 1969; McPhie 1973; Sandoval and 

Gould 1978; Roundy and others 1983; Roundy 1985). 

A sagebrush/grass site and a greasewood site in northern Utah were selected to test the adaptability of 20 and 

24 plant species, respectively. The objectives of this study 

were to 1) evaluate establishment of selected species on 

the respective sites and 2) evaluate the longevity of green 

tissue for the same species. 

Study Site _________ _ 

The study area was located in northern Utah immediately 

southwest of Utah Lake. This area receives an average of 

250 to 300 mm of precipitation per year with the majority 

coming as snow or winter rain. The mean annual air temperature varies between 7.2 and 11.1 DC, and the frost free 

period is between 100 and 140 days. Soil types in the general 

area range from silt clay loams to sandy loams with a slope 

between 0 and 5 percent. 

339 
Table 1-Soil analysis for Sagebrush/grass and Greasewood sites. and juniper trees. Analysis of these soils indicated a soil pH 

of 8.20, low levels of nitrogen and phosphorus, and high 

potassium levels (table 1). There were no problems with 

salinity or sodium on the site. Soil classification was 

Linoyer series, coarse-silty, mixed (calcareous), mesic Xeric 

Torrifluvents (USDA 1984). 

Soil test 

N itrate-N itrogen 

ppm N 

Phosphorus 

ppm P 

Potassium 

ppm K 

Salinity-ECe 

mmhos/cm 

Calcium 

ppm Ca 

Magnesium 

ppm Mg 

Sodium 

ppm Na 

Sodium Adsorption 

Ratio (SAR) 

Sagebrush/grass 

9.54 

9.87 

1,065.60 

1.15 

83.00 

19.00 

112.64 

2.89 

Greasewood 

3.32 

29.10 

688.00 

2.10 

37.00 

6.50 

424.96 

16.90 

The second site (greasewood), an alkali flat range site 

(USDA 1993), was located 7 km north of Elberta, Utah and 

2 km east of state highway 68. This site was dominated by 

greasewood with a sparse understory of other annual forbs 

and grasses. A soil analysis indicated a pH of 8.40 and low 

levels of nitrogen, but high levels of phosphorus and potassium (table 1). There were no problems with salinity, but a 

medium sodium hazard existed, with the site having a 

SAR of 16.90 (Richards 1954). Soil classification was 

Manassa series, fine-silty, mixed (calcareous), mesic Xeric 

Torriorthents (USDA 1984). 

Materials and Methods ____ _ 

Two range sites were used to evaluate the adaptability of 

several species. The first site (sagebrush/grass), a semidesert gravelly loam range site (USDA 1993), was located 

1 km north of Elberta, Utah and 2 km west of state highway 

68. This was an upland site with current vegetation dominated by annual weedy species and interspersed shrubs 

At each range site the area was disked to remove the 

existing vegetation. The species to be tested were then 

seeded into a randomized four replicate complete block 

experimental design with 24 and 20 species in the sagebrush/grass and greasewood sites, respectively (table 2). 

Within each block, each species was planted in 10-row 

sections which were 3 m wide by 9 m long. Plots were seeded 

340 

Table 2-Plant Materials used at study sites. 

Common name 

Oahe Intermediate Wheatgrass 

Luna Pubescent Wheatgrass 

Nordan Crested Wheatgrass 

P27 Siberian Wheatgrass 

Vavilov Siberian Wheatgrass 

Ephraim Crested Wheatgrass 

Hycrest I Crested Wheatgrass 

Hycrest II Crested Wheatgrass 

Douglas Crested Wheatgrass 

Broadleaf Crested Wheatgrass 

Critana Thickspike Wheatgrass 

Secar Snake river Wheatgrass 

Bannock Thickspike Wheatgrass 

Goldar Bluebunch Wheatgrass 

NewHy Hybrid Wheatgrass 

RSH Quackgrass Cross 

Alkar Tall Wheatgrass 

SL Hybrid Wheatgrass 

Magnar Great Basin Wildrye 

Trailhead Basin Wildrye 

Bozoisky Russian Wild rye 

Syn A Russian Wild rye 

Shoshone Beardless Wild rye 

Altai Wildrye 

Regar Meadow Bromegrass 

Paloma Indian Ricegrass 

Spreador II Alfalfa 

Alfagraze Alfalfa 

Remont Sainfoin 

Scientific name 

Agropyron intermedium 

Agropyron intermedium 

Agropyron crista tum 

Agropyron fragile 

Agropyron fragile 

Agropyron crista tum 

Agropyron crista tum X desertorum 

Agropyron crista tum X desertorum 

Agropyron crista tum 

Agropyron crista tum 

Elymus lanceolatus 

Elymus lanceolatus 

Elymus lanceolatus 

Elymus spicatus 

Elymus hoffmanni 

Elymus hoffmanni 

Elymus elongatus 

Pseudoroegneria spicata X 

Elymus lanceolatus 

Elymus cinereus 

Elymus cinereus 

Elymus junceus 

Psathyrostachys juncea 

Elymus trticoides 

Leymus angustus 

Bromus riparius 

Stipa hymenoides 

Medicago sativa 

Medicago sativa 

Onobrychis viciifolia 

Site planted 

Both 

Sagebrush/grass 

Both 

Both 

Both 

Both 

Both 

Sagebrush/grass 

Greasewood 

Both 

Sagebrush/grass 

Sagebrush/grass 

Sagebrush/grass 

Sagebrush/grass 

Both 

Greasewood 

Greasewood 

Both 

Both 

Both 

Both 

Both 

Greasewood 

Greasewood 

Sagebrush/grass 

Sagebrush/grass 

Both 

Greasewood 

Both 

USDA Forest Service Proceedings RMRS-P-9. 1999 
with a John Deere flex planter at seeding rates of approximately 11 kg per hectare. The sagebrush/grass site was 

seeded in the fall of 1992, and the greasewood site was 

seeded in the fall of 1993. 

In June of 1995, each plant species was rated for row 

uniformity and density on a scale from 1 to 10; 10 being the 

highest rating. Uniformity was an evaluation of plant spacing along the length of the row. Density was an evaluation 

of the relative number of plants per unit area. A stand 

performance index (SPI) was then calculated by multiplying 

the uniformity and density ratings. 

The longevity of green foliage was also evaluated for each 

species. The greenness of foliage was evaluated at 1 to 4 

week intervals through the growing season, beginning May 

19 and ending August 10. A rating of 70 percent indicated 

that 70 percent of the foliage was green and 30 percent was 

dry. 

Standard analysis of variance methods were used to 

compare species, and a protected LSD mean separation 

technique was used to distinguish performance between 

species (Ott 1988). A total of 29 plant species were seeded 

between the two sites, with some species being seeded at 

both sites (table 2). 

Results __________ _ 

A wide range of density and uniformity ratings was 

found among plant species. The two ratings were tightly 

correlated for most species. The product of the density and 

uniformity ratings for each species was calculated, and used 

as a Stand Performance Index (SPI). Analysis of variance 

showed significant differences for stand performance among 

species (p :::; 0.01). Interaction between site and species was 

also significant (p :::; 0.01). Plant species were ranked in 

order from highest to lowest according to the Index for each 

site (tables 3 and 4). Siberian and crested wheatgrasses 

outperformed other species at the sagebrush/grass site. The 

top five varieties were P-27 Siberian, Ephraim, Hycrest I, 

Hycrest II, and Vavilov. These varieties scored significantly 

higher SPIs than the rest of the species. On the greasewood 

site, Alkar tall wheatgrass performed the best with a SPI 

almost 8 points higher than the other species, but it was not 

significantly higher than the other top 12 species (table 4). 

Remont sainfoin (Onobrychis uiciifolia) was ranked the 

lowest at both sites, being in the statistically lowest group 

along with five other species at the sagebrush/grass site 

(table 3), and being significantly lower than all other species 

at the greasewood site. Significant interaction between site 

and species occurred because plants such as NewHy and 

RSH quackgrass cross were in the statistically highest 

ranked group at the greasewood site, while being in the 

statistically lowest ranked group at the sagebrush/grass 

site. Overall, a larger group of plant species performed 

better at the greasewood site than at the sagebrush/grass 

site. Sixty-five percent of the species seeded at the greasewood site were in the statistically highest ranked group, 

with only one species beingin the statistically lowest ranked 

group. At the sagebrush/grass site only 21 percent of the 

species were in the statistically highest ranked group, while 

25 percent were in the statistically lowest ranked group. 

Plant species at the two sites began to show statistical 

differences (p < 0.05) in percent greenness by the middle of 

July. By the last collection date, August 10, the differences 

Table 3-Species establishment at the Sagebrush/grass site. 

Stand 

Rank Species Density Uniformity performance index 

1 P27 Siberian Wheatgrass 9.03 9.00 81.3 a 

2 Ephraim Crested Wheatgrass 8.59 9.17 78.9 a 

3 Hycrest I Crested Wheatgrass 8.53 9.20 78.5 ab 

4 Hycrest II Crested Wheatgrass 8.26 9.36 77.3 ab 

5 Vavilov Siberian Wheatgrass 8.33 9.03 75.2 abc 

6 Syn A Russain Wildrye 7.97 8.63 68.8 bcd 

7 Broadleaf Crested Wheatgrass 7.87 8.33 65.6 cde 

8 Bozoisky Russian Wildrye 7.47 8.17 61.0 def 

9 Luna Pubescent Wheatgrass 7.30 7.97 58.2 efg 

10 Bannock Thickspike 7.17 8.03 57.6 efgh 

11 Nordan 7.20 7.50 54.0 fghi 

12 Paloma Indian Ricegrass 6.77 7.63 51.7 fghij 

13 Critana Thickspike Wheatgrass 7.03 7.00 49.2 fghij 

14 Trailhead Basin Wild rye 5.97 7.97 47.6 hij 

15 SL Hybrid Wheatgrass 6.63 6.83 45.3 ij 

16 Magnar Basin Wildrye 6.10 7.10 43.3j 

17 Oahe Intermediate Wheatgrass 6.03 6.83 41.2 j 

18 Spreador II Alfalfa 5.50 5.93 32.6jk 

19 Secar Snake river Wheatgrass 3.97 4.47 17.8 kl 

20 RSH Quackgrass Cross 3.47 4.00 13.9 kl 

21 NewHy 3.50 3.77 13.2 kl 

22 Goldar Bluebunch Wheatgrass 3.00 3.57 10.71 

23 Regar Meadow Bromegrass 1.97 3.17 6.21 

24 Remont Sainfoin 0.83 0.93 0.81 

USDA Forest Service Proceedings RMRS-P-9. 1999 341 
Table 4-Species Establishment at the Greasewood site. 

Stand 

Rank Species Density Uniformity performance index 

1 Alkar Tall Wheatgrass 9.53 9.97 95.0a 

2 Vavilov Siberian Wheatgrass 8.83 9.83 87.7 ab 

3 Bozoisky Russian Wildrye 8.73 9.93 86.7 ab 

4 Nordan Crested Wheatgrass 9.03 9.53 86.1 ab 

5 P27 Siberian Wheatgrass 8.67 9.83 85.2 ab 

6 Hycrest I Crested Wheatgrass 8.27 10.00 82.7 ab 

7 Syn A Russain Wild rye 8.57 9.27 79.4 abc 

8 NewHy 8.50 9.20 78.2 abc 

9 RSH Quackgrass Cross 8.67 8.93 77.4 abcd 

10 Douglas Crested Wheatgrass 8.27 9.30 76.9 abcd 

11 Trailhead Basin Wildrye 8.23 9.17 75.5 abcd 

12 Broadleaf Crested Wheatgrass 8.13 9.27 75.4 abcd 

13 Oahe Intermediate Wheatgrass 7.83 9.23 72.3 abcde 

14 Critana Thickspike Wheatgrass 8.03 7.77 62.4 bcde 

15 Shoshone Beardless Wheatgrass 7.03 7.63 53.6 cdef 

16 Altai Wildrye 6.47 6.87 44.5 f 

17 Spread~r II Alfalfa 6.33 7.00 44.3f 

18 Magnar Basin Wildrye 6.00 6.80 40.8 f 

19 Alfagraze Alfalfa 5.63 5.83 32.8 f 

20 Remont Sainfoin 1.30 1.30 1.7 9 

were quite evident (tables 5 and 6). There was much greater 

variation in greenness within species by August 10, making 

it more difficult to distinguish between species statistically. At the sagebrush/grass site on August 10, both 

varieties of Basin wildrye and Remont sainfoin had ratings 

of 80 percent green tissue or above. Table 5 shows that the 

first ten species stayed significantly greener longer than the 

rest of the species at that site. At the greasewood site, 

Remont Sainfoin received the highest rating on the last date, 

with the first 12 species listed on table 6 also being significantly higher than the other species at the site on August 10. 

By August 10, thirty-eight percent of the plants at the 

sagebrush/grass site were significantly lower than the rest 

of the spec;es at that site with Vavilov Siberian wheatgrass receiving the lowest ranking. At the greasewood site, 

30 percent of the species were in the statistically lowest 

ranked group, with Critana thickspike wheatgrass receiving the lowest rank on August 10. 

Table 5-Percent green tissue remaining for species at the 

Discussion ------------------------------- Different plant species have adapted to different types of 

environmental conditions, with some having a wide range of 

adaptation, and others having a narrow range. These 

adaptability trials indicated that the species evaluated represented a wide range of variation with respect to being 

adapted to these sites. Some species had strong establishment, while others had the ability to remain green into late 

summer. Some species did well in both areas, while others 

proved to be mediocre or poor in both categories. 

342 

Rank 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

Sagebrush/grass site. 

Percent 

green tissue 

Species July 19 August 10 

Magnar Basin Wildrye 89.0 abcd 81.5 a 

Trailhead Basin Wildrye 85.7 cde 80.0 a 

Remont Sainfoin 90.0 abc 80.0 a 

RSH Quackgrass Cross 88.3 abed 75.0 ab 

Spread~r II Alfalfa 88.0 abcd 73.3 ab 

NewHy 84.3 def 72.3 abc 

Goldar Bluebunch Wheatgrass 95.7 a 66.7 abcd 

SL Hybrid Wheatgrass 94.0 ab 63.3 abcde 

Secar Snakeriver Wheatgrass 90.0 abc 59.0 abcdef 

Paloma Indian Ricegrass 64.3 i 55.0 bcdefg 

Critana Thickspike Wheatgrass 83.7 cde 50.7 cdefgh 

Regar Meadow Bromegrass 81.3 efg 49.3 defghi 

Broadleaf Crested Wheatgrass 82.7 ef 48.3 defghi 

Hycrest II Crested Wheatgrass 87.3 bed 43.3 efghij 

Hycrest I Crested Wheatgrass 81.7 efg 37.0 fghijk 

Bannock Thickspike 89.3 abcd 34.0 ghijkl 

Oahe Intermediate Wheatgrass 83.0 cde 33.3 ghijkl 

Nordan Crested Wheatgrass 75.3 gh 30.3 hijkl 

Luna Pubescent Wheatgrass 70.7 hi 28.3 ijkl 

P27 Siberian Wheatgrass 87.7 abcd 26.7 jkl 

Ephraim Crested Wheatgrass 78.7 fgh 21.7 jkl 

Bozoisky Russian Wildrye 81.7 efg 18.7 kl 

Syn A Russian Wild rye 87.0 bcd 15.7 kl 

Vavilov Siberian Wheatgrass 82.0 efg 14.0 I 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 6-Pereent green tissue remaining for speeies at the 

Greasewood site. 

Percent 

green tissue 

Rank Species July 19 August 10 

1 Remont Sainfoin 89.0 a 75.0 a 

2 Magnar Basin Wildrye 79.7 b 73.3 a 

3 Alfagraze Alfalfa 95.0 a 70.0 ab 

4 Trailhead Basin Wildrye 79.0 be 70.0 ab 

5 NewHy 76.7 bed 67.7 ab 

6 RSH Quaekgrass Cross 73.7 bede 67.3 ab 

7 Alkar Tall Wheatgrass 79.0 be 67.3 ab 

8 Spreador II Alfalfa 79.0 bc 65.0 abe 

9 Broadleaf Crested Wheatgrass 71.3 defgh 63.3 abe 

10 Altai Wildrye 70.7 bed 60.0 abe 

11 Syn A Russian Wildrye 74.0 bede 56.7 abe 

12 P27 Siberian Wheatgrass 72.7 edef 55.7 abe 

13 Shoshone Beardless Wildrye 77.0 bed 51.7 be 

14 Nordan Crested Wheatgrass 67.7 efghi 46.7 ed 

15 Hyerest I Crested Wheatgrass 60.7 ijk 28.3 de 

16 Vavilov Siberian Wheatgrass 55.3 k 28.3 de 

17 Douglas Crested Wheatgrass 58.3jk 26.7 e 

18 Bozoisky Russian Wild rye 65.7 fghi 23.3 e 

19 Oahe Intermediate Wheatgrass 65.3 ghij 19.0 e 

20 Critana Thickspike Wheatgrass 62.3 ijk 11.0 e 

At the greasewood site, Alkar tall wheatgrass showed 

good establishment, and also stayed green into August, 

having 67.3 percent green tissue remaining on August 10. 

It has been shown to stay green longer than other wheatgrasses (table 6; Asay 1995) which could be attributed to its 

extremely deep root system (Asay 1995). It was in the 

statistically highest ranked group for both stand performance and percent green tissue remaining. Tall wheatgrass 

is one of the foremost species used for revegetation on 

greasewood sites and is very important for reclamation 

purposes in these areas (Forsburg 1953; Fleck 1967; Rollins 

and others 1968; Malcolm 1969; McPhie 1973; Sandoval and 

Gould 1978; Roundy and others 1983; Roundy 1985). 

Crested wheatgrass varieties established well on both 

study sites but did not remain green through the end of the 

summer. The performance on these sites corresponded with 

crested wheatgrass performance in other areas. Crested 

wheatgrass has been found to provide excellent spring 

forage, but quality declines rapidly (Welsh and others 1993; 

Asay 1995). Although the crested wheatgrass varieties which 

were used had low percent green tissue on the last collection 

date, they still remained green longer than expected from 

previous reports. This probably occurred because of the 

especially cool and wet spring and summer in 1995. This 

area received 229 mm of precipitation in May and 68 mm of 

rain in June, which equaled the long-term mean annual 

precipjtation. Although crested wheatgrass varieties are not 

commonly planted for summer forage, its excellent establishment properties make it highly desirable for soil stabilization. For example, the first important use of crested 

wheatgrass occurred on the Great Plains, saving large tracts 

of soil during the dust bowl of the 1930's (Asay 1995). 

Most of the wildrye varieties used in this study have 

histories of poor seedling vigor and poor establishment 

USDA Forest Service Proceedings RMRS-P-9. 1999 

properties (Asay 1995). Bozoisky Russian wildrye and Syn A 

Russian wildrye were both selected for improved establishment and seedling vigor (Asay 1992), and did outperform 

the other wildryes receiving high scores on the Stand Performance Index (tables 3 and 4). Both basin wildryes had high 

percentages of green tissue throughout the summer at both 

sites (tables 5 and 6). At the sagebrush/grass site neither had 

strong establishment (tables 3 and 4), while at the greasewood site, Trailhead basin wildrye performed well, receiving 

an Index score of 75.5 and was in the statistically highest 

ranked group. Trailhead basin wildrye has been found to 

outproduce Magnar great basin wildrye under drought conditions (Asay 1995). Basin wildryes have proven to be important plant materials in revegetation of greasewood sites 

(Roundy and others 1983; Roundy 1985). 

Thickspike wheatgrass varieties performed average to 

poor on both sites for stand performance. Critana thickspike, 

SL hybrid, and Bannock thickspike were not in the highest 

or lowest groups, but Secar snakeriver wheatgrass was in 

the statistically lowest group at the sagebrush/grass site. At 

the sagebrush/grass site, SL hybrid and Secar snakeriver 

wheatgrass were in the statistically highest group for percent green tissue remaining on August 10. Critana was 

average, and Bannock thickspike was in the statistically 

lowest grou p. Secar snakeriver w heatgrass has shown excellent drought tolerance in the past (Asay 1995). SL hybrid 

also has drought tolerance (Asay and others 1991). 

Bluebunch wheatgrass performed very poorly at the sagebrush/grass site, being in the statistically lowest group for 

stand performance. On the greasewood site NewHy and 

RSH quackgrass cross were in the statistically highest 

group. It is not surprising that these two varieties would act 

similarly because they are both crosses between bluebunch 

wheatgrass and quackgrass (Asay 1992). RSH is the naturally occurring form ofN ew Hy. It is also not surprising that 

they would do well on the greasewood site because they 

have high salt tolerance. Bluebunch wheatgrass was in the 

statistically highest group at both sites for percent green 

tissue remaining on August 10. This supports other findings 

that bluebunch wheatgrass is adapted to dry areas (Asay 

1995). 

Although Regar meadow bromegrass has shown rapid 

seedling establishment in other areas (USDA 1994), it was 

in the statistically lowest group for stand performance, 

receiving an index score of 6.2 at the sagebrush/grass site 

(table 3). It has also shown drought tolerance in other areas 

(USDA 1994), but received a marginal rating of percent 

green tissue remaining (table 5). 

Paloma Indian rice grass performed marginally in stand 

performance and percent green tissue remaining (tables 3 

and 5). In other areas it has shown excellent stand establishment and relative drought tolerance (USDA 1994). 

Although both varieties of alfalfa, Spreador II and 

Alfagraze, did not receive high Stand Performance Index 

scores, alfalfa would be a valuable plant to have in a species 

mix. Mature alfalfa plants can recover from heavy grazing, 

while seedlings have great difficulty recovering (Stevens 

and Monsen 1998). Alfagraze alfalfa is adapted to areas 

that are irrigated or have average annual precipitation 

higher than at these sites (Monsen and Horrocks 1996, 

personal communication), as such, it is not surprising that it 

did not exhibit high performance under extreme conditions. 

343 
Alfagraze probably should not be used in seeding mixes in 

these environments without irrigation. IfSpreador II seedlings can be protected for 2 or 3 years, surviving plants 

should be long lived in the community (Stevens and Monsen 

1998). The value of including a legume like alfalfa in a mix 

is that it greens up early and stays green longer than many 

grasses (Stevens and Monsen 1998). 

Remont sainfoin is another plant which demonstrated 

poor establishment, but ifit could be established, it would be 

valuable for grazing purposes. It greens up early and stays 

green long into the grazing season (Stevens and Monsen 

1998). Remont Sainfoin remained green longer than almost 

all of the species at both sites (tables 5 and 6). 

The high establishment and growth rate for many species 

on the greasewood site was unusual for such a site. Success 

could be attributed to high amounts of precipitation in the 

spring of 1995 (Roundy and others 1983; Roundy 1985). 

Another possible explanation, is that the site is sodic and 

not saline-sodic. Available water would not have been 

restricted by low matric and osmotic potentials as is often 

the case in saline soils (Rollins and others 1968; Sandoval 

and Gould 1978; Roundy and others 1983; Roundy 1985). 

Conclusions ------------------------------- Reclamation projects can have many different objectives. 

The desired objectives of the project determines what plant 

species are used. If the objective is soil stabilization then 

crested wheatgrass would be a good species to use. If the 

objectives included lengthening the grazing season, then a 

species like alfalfa, which remains green through the summer, would be a better choice. Plant species used also 

depends on the site being reclaimed. For example, Trailhead 

basin wildrye had an Index score of 47.6 at the sagebrush! 

grass site while receiving a score of75.5 on the greasewood 

site. Difference in soil type, water relations, and history of 

use can impact the site and which species are adapted. 

Although objectives for an area will help determine which 

species should be planted, a mix of native and introduced 

grasses along with some shrubs has been shown to improve 

overall plant prod uction in arid and semi arid areas (Roundy 

and Call 1988). Further studies could be performed to 

determine which mix of species grow best together, and to 

determine which species are preferred by grazing animals. 

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345 
Response of a Seed Mix and Development of 

Ground Cover on Northerly and Southerly 

Exposures in the 1985 Jarvies Canyon Burn, 

Daggett County, Utah 

Sherel Goodrich 

Allen Huber 

Abstract-Response ofa seed mix and recovery of plant and litter 

cover are compared for adjacent southerly (warm) and northerly 

(cool) exposures within a burn within the pinyon-juniper belt. 

Various plant species responded differently to the different exposures. Response of seeded and some nonseeded species are discussed. Mter 10 years, ground cover that provided protection 

against rain drop splash and sheet wash was 79 percent on the warm 

exposure and 97 percent on the cool exposure. Soil standards for 

cover should reflect different site specific capabilities as demonstrated on these two exposures. 

Wildlands present a variety of ecological niches within 

many project areas with variation in exposure, gradient, 

slope position incl uding drainage bottoms, change in geology 

and soils including amount of rock at the soil surface and in 

the soil profile, and other features. Seedings of burned areas 

and other projects are more likely to achieve desired objectives for cover, species diversity, forage supply over a greater 

part of a year, and higher production when they include a 

mix of species that can respond to site differences within the 

project area (Plummer and others 1968). At this study area, 

exposure is expected to be the major feature of difference in 

response of different plants. 

Study Sites ________ _ 

The study sites are within the Jarvies Canyon Burn of 

1985. This burn is in the Green River corridor north of the 

Flaming Gorge Dam in Daggett County, Utah, and about 3 

miles northwest of the town of Dutch John and the Flaming 

Gorge Weather Station. Records from this weather station 

from 1957 through 1992 indicate annual precipitation of 

12.50 inches of which 63 percent comes in the April through 

September period (Ashcroft and others 1992). The study 

sites are within the Uinta Mountain Section as defined by 

McNab and Avers (1994), and within a landtype composed of 

ridge and ravine topography underlain by Precambrian 

quartzitic materials and shales of the Uinta Mountain 

Group. Elevation ofthe burn ranged from 6,200 to 6,800 feet. 

The study sites were at about 6,700 feet. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Sherel Goodrich is Forest Ecologist, Ashley National Forest, Vernal, UT 

84078. Allen A. Huber is Range Technician, Duchesne District, Ashley 

National Forest, Duchesne, UT 84021. 

346 

Two general phases lie within the landtype. One phase is 

on northerly (cool) exposures where alder-leaf mountainmahoganylbluebunch wheatgrass (Cercocaprus montanus 

Raf./Elymus spicatus [Pursh] Gould) communities with high 

plant diversity are seral to pinyon-juniper. The other phase 

is on southerly (warm) exposures where communities are 

often dominated by rubber rabbitbrush (Chrysothamnus 

nauseosus [Pallas] Britt.), mountain big sagebrush (Artemisia tridentata var. pauciflora Winward & Goodrich), and 

grasses. These communities are also seral to pinyon-juniper. 

Gradient of the study site of cool exposure is about 15 

percent, while that ofthe warm exposure is about 20 percent. 

On the warm exposures cheatgrass (Bromus tectorum L.) 

has proven to be a highly competitive plant. It was of much 

lower frequency on the cool exposure. 

Prior to burning, the sites were dominated by mature 

stands of pinyon-juniper with canopy cover in excess of 50 

percent on the cool exposure and somewhat less than this on 

the warm exposure. In the fall of 1985, 233 acres were 

burned by helitorch and aerial seeded in a cooperative 

project between the Utah Division of Wildlife Resources and 

the Ashley National Forest in which the Forest Service was 

responsible for burning and aerial application of seed, and 

Utah Division of Wildlife Resources supplied the seed mix 

(table 1). Both cool and warm exposures were burned, and 

intensity and spread of fire was sufficient to achieve essentially 100 percent mortality of pinyon andjuniperwithin the 

perimeter of the burn. 

The burn area had been closed to permitted livestock 

grazing since the early 1960's. Age and canopy cover of stands 

within the burn area indicate low presence of understory 

species through much of the 1900's. Permitted livestock use is 

Table 1-Seed mix applied aerially to the burn in the fall of 1985. 

Species Seed per acre Seeds per acres 

Ib 

Fairway crested wheatgrass 1 175,000 

Intermediate wheatgrass 1 150,000 

Lincoln smooth brome 3 213,000 

Pi ute orchardgrass 2 1,308,000 

Hard fescue 2 1,360,000 

Ladak alfalfa 2 400,000 

Small burnet 2 55,115 

Yellow sweetclover 1 520,000 

Mountain big sagebrt.Jsh 1 2,575,940 

Total 15 

BOetermined from seeds per Ib as given in Plummer and others (1968) and 

Stefferud (1948). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
", ,~ 

expected to have been comparatively low at this site prior to 

the 1960's and none since that time. 

The seed mix applied to the area included Fairway crested 

wheatgrass (Agropyron cristatum [1.] Gaertner), Intermediate wheatgrass (Elymus hispidus [Opiz] Meld.), Lincoln 

smooth brome (Bromus.inermis Leysser), Piute orchardgrass 

(Dactylis glomerata L.), hard fescue (Festuca ovina var. 

duriuscula [L.] Koch.), Ladak alfalfa (Medicago sativa L.), 

Small burnet (Sanguisorba minor.Scop.), Yellow sweetclover 

(Melilotus officinalis [L.] Pallas), and mountain big sagebrush (table 1). The moisture year that followed burning and 

seeding was favorable for establishment and growth of 

plants. In addition to the seeded species, cheatgrass and 

Japanese chess (Bromusjaponicus Thumb.) became abundant enough to be significant in sampling at the sites. There 

were a few other native and introduced species of low 

frequency found on the sites. 

Those oflow frequency found in plots on the cool exposure 

were mostly natives. These were low penstemon (Penstemon 

humilis N utt.), mountain dandelion (Agoserisglauca [Pursh] 

Raf.), and rockcress (Arabis L.). For the warm exposure, 

native species of low frequency found in plots were Ross 

sedge (Carex rossii Boott), tansy mustard (Descurainia 

pinnata [Walt.] Britton), narrowleaf goosefoot (Chenopodium leptophyllum [Moq.] Wats.), and hairy goldenaster 

(Heterotheca villosa [Pursh] Shinners). Introduced species 

of low frequency on the warm exposure were false flax 

(Camelina_microcarpa Andrz. in DC.), and Russian thistle 

(Salsola pestifer A. Nels.). 

Methods and Results 

Rooted nested frequency (table 2) was determined in each 

of four nested plot sizes for all species at 100 sample points 

on each of the cool and warm exposures. Canopy cover of 

shrubs was determined on 500 feet ofline intercept. Ground 

cover (tables 3 and 4) was determined from 400 point 

samples on each exposure. Methods for nested frequency, 

line intercept, and ground cover used in this study are 

outlined by U.S. Department of Agriculture, Forest Service 

(1993). Belt lines along which each of the above data sets 

were taken were permanently marked. Samples were taken 

Table 2-Nested frequency scores for the two sites in 2 years 

based on potential score of 400. 

Species Warm exposure Cool exposure 

1991 1996 1989 1996 

Fairway crested 159a 264a 166a 138a 

wheatgrass 

Intermediate 32 26 35a 24a 

wheatgrass 

Hard fescue 72a 148a 207a 277a 

Piute orchardgrass 10 8 121 a 90a 

Lincoln smooth brome 56 57 137a 243a 

Cheatgrass 30a 155a 0 0 

Japanese chess 50a 77a 9 0 

Ladak alfalfa 164a 145a 104 103 

Yellow sweetclover 0 0 0 0 

Small burnet 23 0 0 0 

aThe spread in scores for these species between years indicates significance 

at 80 percent probability (Chi Square = 1.642 with 1 degree of freedom). 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Table 3-Development of ground cover as measured at 400 points 

on each the warm and cool exposures. Values shown are 

the number of points for each parameter of cover. 

Site Veg. Litter Moss Rock Pave. Soil Total 

Warm exposure 1991 24a 117a 0 93a 47 119a 400 

Warm exposure 1996 96a 184a 35a 39 45a 400 

Cool exposure 1989 37a 211 a 13a 25a 6 108a 400 

Cool exposure 1996 182a 174a 22a 8a 1 13a 400 

aThe spread in scores for these values between 1991 and 1996 for the warm 

exposure and between 1989 and 1996 for the cool exposure is indicated to be 

significant at 80 percent probability (Chi Square = 1.642 with 1 degree of freedom). 

Table 4-Development of ground cover (expressed as percent) 

following fire. 

Site Veg. Litter Moss Rock Pave. Soil Total 

Warm exposure 1991 6 29 0 23 12 30 100 

Warm exposure 1996 24 46 9 0 11 100 

Cool exposure 1989 9 53 3 6 2 27 100 

Cool exposure 1996 46 44 6 2 3 101 

in 1989 and 1996 on the cool exposure and in 1991 and 1996 

on the warm exposure. On the cool exposure, production 

(table 5) of above ground annual production (air dry weight) 

was measured in four different years in 10 random placed 

plots of9.6 ft2. No production measurements were taken on 

the warm exposure. 

Dispersion of ground cover is indicated by quadrat frequency as well as nested frequency. In the 10th year after 

treatment, onlyoneof100quadratsof19.7by 19.7 inches (50 

by 50 em) on the warm exposure did not have a perennial 

plant in it, and only eight of 100 nested plots of 9.8 by 9.8 

inches (25 by 25 em) did not have a perennial plant in them. 

By the 10th year, all 100 quadrats on the cool exposure had 

perennial plants in them, where only one of 100 nested plots 

of9.8 by 9.8 inches did not have a perennial plant in it. The 

closely spaced plants with numerous fine stems indicate 

high value for dispersion of plants in relation to watershed 

protection. 

Line intercept data showed no shrub cover on the warm 

exposure and rubber rabbitbrush crown cover of 0.3 percent 

in 1989 and 0.8 percent in 1996, and big sagebrush crown 

cover of 0 percent in 1989 and 1.8 percent in 1996. 

Discussion and Management 

Implications ________ _ 

All seeded species except alfalfa and small burnet had 

higher frequency in 1989 on the cool exposure than they did 

in 1991 on the warm exposure. There are 2 years between 

these readings. However, greater establishment for all seeded 

species except alfalfa and small burnet is strongly indicated 

for the cool exposure. The difference in years supports this 

conclusion. 

Lower production in 1989 was perhaps a function of 

precipitation of poor timing and low amounts. However, an 

obvious difference is the low prod uction of alfalfa in that year 

347 
Table 5-Aboveground herbaceous annual production on the cool exposure. 

Pounds per Percent Composition 

Species acre air dry weight by air dry weight 

1989 1991 

Fairway crested wheatgrass 247 372 

Intermediate wheatgrass 30 62 

Lincoln smooth brome 57 258 

Piute orchardgrass 167 37 

Hard fescue 310 279 

Ladak alfalfa 50 526 

Small burnet 0 3 

Yellow sweetclover 0 0 

Mountain big sagebrush 0 0 

Totals 860 1541 

compared to the later years. Much of the higher production 

oflater years is a function of maturation and greater prod uction of alfalfa. 

Variation in production and percent composition based on 

species production found at this site indicates problems for 

standards and monitoring based only on measurement of 

weight. Rather wide variations can be expected as a function 

of timing and amounts of precipitation and variations in 

temperature that are independent of management practices. A hard freeze in June, which has happened here, can 

greatly reduce production and change composition from that 

of other years with more favorable temperatures. 

Ground cover provided by vegetation and litter increased 

significantly and bare soil decreased significantly with time 

as plants became established and produced litter. After 10 

growing seasons, potential for cover providing protection 

against raindrop splash and sheet erosion (vegetation, litter, moss, and rock) is indicated to be 79 percent for the warm 

exposure and 97 percent for the cool exposure. Additional 

monitoring might show additional increase in ground cover 

on the warm exposure, but since. percent ground cover on the 

cool exposure approached 100 percent, it can be considered 

at potential. The warm, dry conditions of the warm exposure 

indicates less than 100 percent as potential, and perhaps the 

79 percent measured after 10 years is close to potential. 

Soil standards for soil protection should include differences in potential ground cover for cool and warm exposures. 

The Decision Notice for the Environmental Assessment for 

Flaming Gorge Pinyon-Juniper Treatment (U.S. Department of Agriculture, Forest Service 1985) that applied to the 

Jarvies Canyon and other burns of the area included an 

objective to "Re-establish 70% ground cover in five years" 

after treatment. This standard seems fairly reasonable 

considering the information available on which to make the 

decision, and on the cool exposure this standard was met. 

However, after 5 years, cover of vegetation , litter, and rock 

totaled 58 percent on the warm exposure, which was 12 

percent below the standard. If pavement (12 percent) was 

considered effective cover, the standard would have been 

met. However, pavement (rock fragments less than 0.75 

inches diameter) on these slopes is of questionable value for 

watershed protection. The data indicate more specific standards could be drafted for cool and warm exposures. 

Also included in management goals and objectives of 

the environmental analysis was a standard to "produce a 

348 

1993 1996 1989 1991 1993 1996 

145 186 29 24 7 13 

41 113 3 4 2 8 

171 197 7 17 8 14 

78 12 19 2 4 1 

701 316 36 18 34 22 

911 591 6 34 44 41 

4 0 0 0 0 0 

0 0 0 0 0 0 

0 

2051 

24 0 0 0 2 

1439 

minimum of 300 lb per acre of desirable plant species on 

treated sites within five years". The data indicate this standard is far below the potential for at least the cool exposure. 

However, duration of high production is yet to be determined. 

Evaluation and Management 

Implications for Different Species _ 

Shrubs-The only shrubs found on the study sites were 

big sagebrush and rubber rabbitbrush. Shrubs were found 

only on the cool exposure and were of low frequency in all 

years samples were taken. Line intercept data showed 

rubber rabbitbrush increased from 0.3 percent crown cover 

to 0.8 percent from 1989 to 1996 while big sagebrush increased from 0 to 1.8 percent. 

Additional monitoring over time will be needed to track 

the dynamics of shrubs, but this slight change indicates they 

will increase in time. Morphology and browsing preference 

by wild ungulates indicate both the seeded mountain big 

sagebrush and indigenous basin big sagebrush (Artemisia 

tridentata N utt. tridentata2 established after the fire. Mountain big sagebrush was closely hedged, while apparent 

plants of basin big sagebrush were hedged lightly or not at 

all. 

Crested wheat grass-Crested wheatgrass increased 

significantly from 1991 to 1996 on the warm exposure and 

decreased significantly from 1989 to 1996 on the cool exposure. By 1996 it was the most frequent species on the warm 

exposure and third most frequent species on the cool exposure. This species demonstrated high value for control of 

cheatgrass by rapid establishment and increase over time on 

the warm exposure. The decrease over time on the cool 

exposure indicates it is less competitive there. It also indicates it might be quite compatible with native bluebunch 

wheatgrass on cool exposures. Considering the portion of the 

seed mix in pounds as well as number of seeds, this species 

demonstrated comparatively high economic performance as 

well as ecological performance. Low amounts of crested 

wheatgrass in seed mixes for this area are indicated by low 

cost and high value for cheatgrass control. Davis and Harper 

(1990) documented an increase in crested wheatgrass in the 

third year following seeding in a juniper-pinyon chaining in 

USDA Forest Service Proceedings RMRS-P-9. 1999 
central Utah. Their data indicated much lower establishment of crested wheatgrass than found at Jarvies·Canyon. 

Intermediate wheatgrass-Frequency of intermediate 

wheatgrass remained low through 1996 on both exposures 

where it decreased with time. This seems unexpected by 

comparison of nearby seedings where this species was seeded 

alone or as the major part of a seed mix where it rather 

quickly established solid stands. Performance in this seeding might indicate this is not so competitive when seeded in 

a mix. However, Davis and Harper (1990) documented 

results of seeding a mix in central Utah where intermediate 

wheatgrass was the most abundant seeded species. They 

also reported precipitation well above normal was concurrent with seedling establishment. The variable response of 

this species demonstrates the value of a diverse seed mix 

since it is unknown which species will do well in different 

seedings. This species often seems to establish in great 

abundance and become oppressively dominant or with low 

frequency following seeding. This "all or nothing" response 

in seedings indicates low desirability for this plant where 

diverse communities are desired. In the Jarvies Canyon 

seeding, seed of this species could have been replaced with 

that of bluebunch wheatgrass without putting watershed 

protection or cheatgrass control at risk. 

Lincoln smooth brome-On the warm exposure, frequency of this species remained the same between the 5th 

and the 10th year post treatment. However, it increased 

dramatically on the cool exposure. The relatively low response of smooth brome on the warm exposure indicates low 

value for cheatgrass control. Compared to crested wheatgrass, hard fescue, and alfalfa, smooth brome was of low 

value for this purpose. It was slow starting on the cool 

exposure, which indicates low value for initial weed control 

there. It is also indicated to have comparatively low val ue for 

watershed protection in the critical, early years. 

The data imply this species is trending toward dominance 

of the herbaceous community on the cool exposure, and 

perhaps it will drive community diversity downward. Although an increase in production of this species was measured between 1989 and 1996, production studies on the cool 

exposure indicate this will be a relatively low producing 

species at this site. Ladak alfalfa and hard fescue have 

produced considerable more herbage and thus litter for 

ground cover than has smooth brome in each of the 4 years 

production measurements have been made at the site since 

the fire. 

The rhizomatous nature of smooth brome and intermediate wheatgrass is one value these plants provide that the 

other species do not. However, smooth brome showed comparatively little value for cheatgrass control and watershed 

protection in the critical early years, and it has an implied 

feature of driving community diversity downward. 

Grea ter weigh t of seed ofthis species was a pplied than any 

another. Although numbers of seed applied might be a valid 

way to compare ecological performance, cost of seed is 

measured in terms of weight, not numbers of seed. This 

indicates poor economic performance in the early years of 

the seeding when cheatgrass control and soil protection are 

most critical. Data over the next decade might show the 

increase in frequency ofthis species is concurrent with lower 

USDA Forest Service Proceedings RMRS-P-9. 1999 

production on the site. Its value for seeding in this setting 

appears to be low. 

The native bluebunch wheatgrass does well on the cool 

exposures of this landtype. Although this species is not 

rhizomatous or is weakly rhizomatous compared to smooth 

brome, it is indicated to have high watershed values on 

similar nearby sites. Replacing smooth brome seed with that 

of bluebunch wheatgrass in seed mixes for this area is 

recommended. 

Piute orchard grass-Orchard grass showed essentially 

no value for cheatgrass control on the warm exposure. 

However, its quick establishment on the cool exposure 

followed by a significant decrease indicates high value there 

for initial weed control and for allowing other species to 

establish over time. Both frequency and production values 

indicate this is less aggressive over time than is smooth 

brome. Considering long-term diversity and greater presence of natives in the community, orchardgrass seems more 

appropriate in seed mixes for this area than does smooth 

brome. 

Hard fescue-This was the only seeded species that 

increased on both the cool and warm exposures. However, it 

established with much higher frequency on the cool exposure. On the cool exposure this was the highest producing 

grass in 3 out of 4 years when production measurements 

were made. This appears to be an aggressive plant at these 

sites with the potential to drive communities to a lower 

diversity. Continued monitoring at this site is needed to 

evaluate the use of this species in future seedings. If it 

continues to increase concurrent with a decrease in other 

desired species, exclusion or much lower rates in the seed 

mix is indicated for future seedings. However, its increase on 

the warm exposure indicates high value for long-term control of cheatgrass. It remains green late in the fall and early 

winter when it is selected by elk (Cervis canadensis) and 

possibly by mule deer (Odocoileus hemionus). 

Ladak alfalfa-This established quickly on both exposures. However, production data from the cool exposure 

indicate it is slower to mature into full production than some 

of the seeded grasses. However, it established with greater 

frequency on the warm exposure than on the cool exposure, 

which was not a feature of any of the seeded grasses, and by 

1991 this was the most frequent species on the warm 

exposure. This indicates high value for reducing cheatgrass. 

Frequency of this species remained the same on the cool 

exposure but declined on the warm exposure. Frequency 

data indicate this species will not increase beyond the level 

of initial establishment. This indicates it will not become 

oppressive to other species, and that it will contribute to 

species diversity. Davis and Harper (1990) found Ladak 

alfalfa decreased in frequency in the second and third years 

after seeding, which indicates possible high establishment 

but also considerable mortality of seedlings and young 

plants. 

After 1989, Ladak alfalfa produced more herbage than did 

any other species on the cool exposure. Ungulate use has 

been light, but alfalfa appears to be the most selected forage 

species by elk and mule deer at this site. Also, Smith (1992) 

recorded alfalfa to be highly selected by bighorn sheep (Ovis 

canadensis) within the Green River corridor. The potential 

349 
of alfalfa for nitrogen fixation is an additional value of this 

plant. However, cheatgrass as well as other grasses can 

respond favorably to increased nitrogen. This feature implies a critical need to include aggressive perennial grasses 

with alfalfa in seed mixes to be used in areas where cheatgrass 

is highly competitive. Most features of this plant indicate 

high value for including it in seed mixes for the pinyonjuniper belt of the Green River corridor. 

Yellow sweetclover-Although yellow sweet clover established from the seeding and put on a great show of tall 

plants in the first two to three growing seasons, it was not 

recorded in the plots by 1989, nor was it seen anywhere in the 

burn in that year. The flush of yellow sweetclover in the 

second growing season was great enough to be of concern to 

wildlife biologists who desired low stature of vegetation for 

high value bighorn sheep habitat. However, from 1989 to 

1997, it was not seen anywhere in the burned area. In this 

setting, yellow sweet clover is indicated to be of value for 

quick establishment of cover with a rapid decline that will 

allow other species to replace it. Yellow sweetclover is often 

considered a highly invasive species. This has not been the 

nature of the plant in the general area of this study where its 

abundance and persistence are quite limited to roadsides 

and other frequently disturbed sites. 

Small burnet-Small burnet was recorded at low frequency on the warm exposure in 1991. By 1996 it was not 

seen in the plots. It was not recorded in the plots on the cool 

exposure in 1989 or 1996. The performance of small burnet 

indicates value of this species is for quick establishment and 

rapid decline, which could allow for establishment of natives. However, comparison of its relatively high percent of 

weight of the seed mix with its relatively low performance 

indicates low economic value for this species when applied in 

a heavy seed mix (15Ib/acre) composed of highly competitive 

species. However, the number of seeds of this species was 

lower than any other in the mix, and the low performance is 

also likely a function offewer seeds. It also seems important 

to note that no measurements were made until 5 years after 

treatment, and like yellow sweetclover, small burnet might 

have been abundant for 2 to 3 years. Davis and Harper 

(1990) recorded high establishment of small burnet in the 

first 3 years of a seeding in central Utah. Measurements in 

the fifth year might not reflect the early value of this plant 

in the seeding. Use of this plant in fire rehabilitation projects 

has been criticized on grounds that its value is for wildlife 

and not for rehabilitation. However, the nature of this plant 

to quickly establish and provide cover and then allow for 

increase of natives as it decreases indicates it is highly 

desirable for fire rehabilitation projects. 

Japanese chess-oJ apanese chess increased on the warm 

exposure, but the increase was much less than for cheatgrass. 

It was found with low frequency in 1989 on the cool exposure, 

and it was not found there in 1996. Compared to cheatgrass, 

this introduced annual appears to be a mild competitor in 

the pinyon-juniper belt. Much focus on cheatgrass in literature with comparatively little coverage for this species 

indicates this is a general nature of this species. 

Cheatgrass-Cheatgrass was not found in the plots on 

the cool exposure, but it increased significantly on the warm 

exposure. Frequency of cheatgrass on the warm exposure 

350 

between the fifth and 10th years might be considered a 

negative indicator. However, the frequency of this winter 

annual can be expected to vary from year to year with 

variations in timing and amount of precipitation as well as 

winter-spring temperatures. Also, high frequency can be 

achieve by numerous, small, single-stemmed plants with 

few seeds. Where this growth form is a function of high 

frequency of vigorous perennial plants, cheatgrass is indicated to have a much subdued effect on plant community 

function. This was the common growth form of cheatgrass in 

the seeding. 

However, the frequency data do indicate the ability of 

cheatgrass to persist even where perennial plants command 

most of the resources of a site even in the absence of 

livestock. Also indicated is the rapid increase in cheatgrass 

following the next disturbance. Also indicated is the potential increase of cheatgrass under management practices 

that reduce frequency or vigor of perennial plants. 

Discussion ----------------------------- The various response of species in the mix indicates the 

importance of seeding a mixture of species on lands of 

diverse exposures. Species diversity in the early seral community was a function of the number of species included in 

the seed mix. Diversity of early seral communities that 

follow disturbance of closed stands of mature or old pinyonjuniper can be expected to be low and to be driven by 

cheatgrass and other weedy species, many of which are 

introduced. These features of pinyon-juniper communities 

strongly point to the need to develop a wide array of plant 

materials with the potential to compete with cheatgrass on 

a variety of exposures and many geological substrates and 

soil types. Concerns for diversity and native species indicate 

the need for development of native plant materials with the 

ability to establish quickly to reduce the influence of introduced, highly invasive species. 

No species or mix of species is likely to elimina te cheatgrass 

on warm exposures, and reduction ofits influence is a more 

realistic goal than eradication. Evidence is strong and growing that cheatgrass has altered many pinyon-j uni per ecosystems to the degree that pure native plant communities are 

no longer a potential. The introduced species seeded at these 

sites represent some of the most capable plants known to be 

able to establish stands rapidly from a single seeding, which 

is important for cheatgrass control. Crested wheatgrass, 

alfalfa, and hard fescue, represent plant materials as capable or more capable of controlling cheatgrass in the pinyon-juniper belt than native grasses and forbs ofthis belt. To 

expect native species to provide better and especially complete control appears to be beyond reason. 

The performance of Ladak alfalfa, crested wheatgrass, 

and hard fescue on the warm exposure demonstrates their 

value in seed mixes where suppression of cheatgrass is a 

goal. At this elevation and precipitation zone, smooth brome 

and orchard grass are indicated to be of less value for this 

purpose. It appears that neither smooth brome or intermediate wheatgrass (rhizomatous species) were needed for 

watershed protection or cheatgrass control. Seed of these 

species could have been replaced by seed of bluebunch 

wheatgrass without loosing ability of the seed mix to establish effective ground cover and provide cheatgrass control. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
References __________________ __ 

Ashcroft, G. L.; Jensen, D. T.; Brown, J. L. 1992. Utah climate. 

Logan, UT: Utah State University, Utah Climate Center. 12? p. 

Davis, J. N.; Harper, K. T. 1990. Weedy annuals and estabhshment of seeded species on a chained juniper-pinyon woodland in 

central Utah. In: McArthur, E. D.; Romney, E. M.; Smith, S. D.; 

Tuller, P. T., compilers. Proceedings-symposium on cheatgrass 

invasion, shrub die-off, and other aspects of shrub biology and 

management; 1989 April 5-7; Las Vegas, NV. Gen. Tech. Rep. 

INT-276. Ogden, UT: U.S. Department of Agriculture, Forest 

Service Intermountain Research Station: 72-79. 

McNab, W. H.; Avers, P. E.1994. Ecological subregions of the United 

States: Section descriptions. Administrative Publication WOWSA-5. Washington, DC: U.S. Department of Agriculture, Forest 

Service. 267 p. 

USDA Forest SeNice Proceedings RMRS-P-9. 1999 

Plummer, P. A; Christensen, D. R.; Monsen, S. B. 1968. Restoring 

big-game range in Utah. Pub. No. 68-3. Ephraim, UT: Utah 

Division of Wildlife Resources, Division ofFish and Game. 183 p. 

Smith, T. S. 1992. The bighorn sheep of Bear Mountain: ecological 

investigations and management recommendations, Provo, UT: 

Brigham Young University. 425 p. Dissertation. 

Stefferud, A, ed. 1948. Yearbook of agriculture. Washington, DC: 

U.S. Department of Agriculture . . . 

U.S Department of Agriculture, Forest ServIce. 198? DecIsIOn 

notice and finding of no significant impact and envIronmental 

assessment: Flaming Gorge pinyon-juniper treatment. Decision 

Notice and Environmental Assessment on' file at: Ashley National Forest, Supervisors Office, 2060 study files, folder 6-l. 

U. S. Department of Agriculture, Forest Service. 1993. Rangeland 

ecosystem analysis and management handbook. FSH 2209-2l. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Region. 4 ch. 

351 
Regrowth of 'Ladak' Alfalfa on PinyonJuniper Rangelands Following Various 

Timing and Types of Spring Use 

Richard Stevens 

Scott C. Walker 

Stuart Wooley 

Abstract-Drought tolerant alfalfa is the most abundantly seeded 

forb on Utah pinyon-juniper ranges. It is eagerly sought after by all 

classes of grazing animals. Generally, mule deer and elk utilize 

areas seeded to alfalfa during winter, early spring and fall, whereas, 

cattle and sheep generally use the same areas during mid spring to 

early summer and fall. Alfalfa in some seedings has been lost 

through year after year late May and June use. In order to properly 

manage and maintain alfalfa on rangelands it is imperative we 

know the effect of timing, type, and amount of use on regrowth and 

subsequent plant vigor. On a deer and elk winter and spring pinyon 

juniper range that had been chained and seeded 20 years earlier, 

sheep were grazed at differing periods. Grazing effect on alfalfa 

forage regrowth and seed production was evaluated. With grazing 

of alfalfa up to May 15, some regrowth offorage and seed production 

did occur. Little regrowth was evident when grazing occurred after 

May 15. Lack of regrowth does not allow alfalfa plants to maintain 

and replenish themselves and to produce seed. 

For over 40 years, drought tolerant range alfalfa has been 

the most abundantly seeded forb on western pinyon-juniper 

ranges receiving over 25 cm annual precipitation (Rumbaugh 

and Townsend 1985; Stevens and Monsen In press). The 

most commonly seeded rangeland cultivar is 'Ladak'. The 

most persistent and best performing cultivars have been 

'Ladak' and 'Nomad.' These cultivars have persisted on 

many seedings for over 28 years (Kilcher and Heinrichs 

1965; Rosenstock and Stevens 1989), however on some 

seedings their persistence has been somewhat less. The 

decrease in density that occurred, has been a result of 

continuous heavy rabbit use and continual spring sheep and 

cattle use (Stevens and Monsen In press; USDA 1971). 

Rangeland cultivars are especially well adapted to the 

sagebrush grass, pinyon-juniper, and mountain brush types. 

They have also been seeded and have done fairly well in the 

aspen, spruce-fir, and subalpine types (Stevens and Monsen 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Richard Stevens was Project LeaderlResearch Biologist (retired); Scott C. 

Walker is Research Biologist, Division of Wildlife Resources, Great Basin 

Experiment Station, Ephraim, UT 84627; Stuart Wooley is a graduate 

student, Brigham Young University, Provo, UT. 

352 

In press). Once established, alfalfa can be very persistent 

and can produce adequate seed to maintain itself(Rumbaugh 

1982). However, little reproduction has occurred from established stands on rangeland sites due to poor seed production 

and consumption of seed by rabbits, rodents, livestock and 

big game (Rosenstock and Stevens 1989). Rhizomatous forms 

do however spread vegetatively, even under arid conditions 

and grazing pressure. In fact, grazing has been shown to 

stimulate rhizome production (Rosenstock and Stevens 1989). 

Drought tolerant alfalfa cultivars have not exhibited much 

regrowth or subsequent seed production following moderate 

to heavy spring use. Spring use could result in very few seeds 

being produced. Big game, livestock, and rodents readily 

consume seed heads in the fall. These two factors, combined 

with the fact that alfalfa seed requires seed coverage adversely affects sexual reproduction. 

Alfalfa is sought out extensively by cattle, sheep, deer, elk, 

rodents and rabbits. Basal leaves can be green throughout 

winter months. New growth starts prior to snow melt and 

generally becomes available mid February to early March. 

Big game generally migrate off pinyon-juniper areas by mid 

May. Livestock grazing generally occurs from May through 

June. Fall use by big game and livestock most often starts in 

early October. It has been observed that when extended 

spring use occurs, there is little or no succulent forage 

available in the fall and that little if any seed is produced. 

Succulent fall forage is a key to healthy big game and for 

keeping big game out of cultivated fields. 

Methods ------------------------------------ Two hundred hectares of pinyon-juniper east of Ephraim, 

Utah were chained and seeded to a mixture of grasses, forbs, 

and shrubs in 1969. The area receives an average annual 

precipitation of 32 cm. 'Ladak' alfalfa was a major component (2.8 kglha) of the seeding. In 1989, 20 years after 

seeding, this study was conducted. Deer and some elk 

utilized the seeding throughout the winter and spring. Even 

with the late spring, a majority ofthe deer and all the elk had 

left the area by May 15. Sheep were allowed on the area 

May 15 through June 25. Eighteen baskets were set out on 

four different dates between September10, 1989 and June 4, 

1990 (total 72 baskets). Each basket was randomly placed 

over one to five alfalfa plants. Adjacent to each basket a like 

number of alfalfa plants were identified and marked. Baskets were round, rodent proof, and 1.5 m in diameter. Dates 

baskets were placed, moved and removed determined grazing periods. Grazing treatments were: 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Date 

Treatment baskets on 

Date 

baskets off Grazing date 

A Sept. 10, 1989 Sept. 15, 1990 No use all year 

B May 15, 1990 Sept. 15, 1990 Spring deer and elk 

use to May 15 

C June 4, 1990 Sept. 15, 1990 Spring deer and elk 

use to May 15; and 

May 15 to June 4 

sheep use 

D May 15, 1990 June 4, 1990 Spring deer and elk 

use to May 15 and 

June 4 to June 24 

sheep use 

Control No baskets No baskets Year long use; 

sheep, deer, and elk 

On September 15, 1990, identified alfalfa plants under 

baskets and adjacent to them were clipped to ground level. 

Number of stems with seeds were identified. Leaves and 

seeds were removed from stems. The length of each stem was 

determined. Stems, leaves, and seeds were air dried and 

weighed. Data was analyzed with one way ANOVA (p < .05). 

Results ------------------------------------ All elk and essentially all deer had moved off the area by 

May 15. When the sheep (ewes with lambs) were put in the 

area on May 15 alfalfa plants that had been available to deer 

and elk (Treatments B,C,D and Control) showed extensive 

use and averaged less than 20 mm in height. On June 24 

when the sheep were removed, grazed alfalfa plants averaged less than 15 mm in height. No use occurred after June 

24 to harvest on Sept. 15. 

Timing of use significantly influenced the amount of 

regrowth that occurred. Plants that were not grazed all year 

(Treatment A) produced an average of 318 grams of stem, 

leaves, and seed (table 1). Plants only exposed to deer and elk 

use up to May 15 (Treatment B) produced significantly less 

(104 grams) regrowth than plants protected all year (Treatment A), and significantly more than those exposed to use 

after May 15 (Treatments C and D), and year long use 

(Control) (table 1). Ungrazed plants (Treatment A) produced 

produced more seed (111 grams) than plants that were 

grazed (treatments B, C, D, and Control) (table 1). Leaf 

and stem production accounted for the majority of the 

regrowth on grazed plants (table 1). Ifplants were grazed in 

the spring or year round grazed, little seed (0.7 to 14 grams 

depending on treatment) was produced (table 1). 

Conclusions ------------------------------ 'Ladak' alfalfa can and has been maintained in pinyonjuniper chainings and seedings for over 30 years. Year after 

year, continued early to late spring use by livestock has 

resulted in loss of alfalfa in some seedings. 

When alfalfa is grazed into the spring, little regrowth 

takes place which is needed to maintain and replenish the 

Table 1-'Ladak' alfalfa growth and regrowth. Average total leaf, stem and seed production, length of stems. and number of stems with seeds 

per plant on September 15 as influenced by five grazing treatments. 

Grazing Total Leaf Stem Seed Stem No. stems 

treatment production (g) production (g) production (g) production (g) length (mm) with seed 

A: 318A* 77A 130A 111 A 287A 5.10A 

No use 

all year 

B: 104B 38M 52B 14B 197B 0.95B 

Spring 

deer and elk 

use to May 15 

C: 34c 15B 18c 0.7B 93c 0.07B 

Spring 

deer and elk 

use to May 

15 and May 

15 to June 4 

sheep use 

D: 48c 19B 26c 3B 100c 0.18B 

Spring 

deer and elk 

use to May 

15 and June 

4 to June 24 

sheep use 

Control: 35c 14B 14c 1B 59D .07B 

Year round use 

'Number within column followed by the same letter are not significantly different (p < .05). 

USDA Forest Service Proceedings RMRS-P-9. 1999 353 
::'-

plant through the summer, fall, and winter, and to produce 

seed for reproduction. Likewise, with no spring regrowth, 

little forage or seed is available for fall and winter use by big 

game and livestock. 

This study demonstrates that grazing to May 15 significantly reduced subsequent regrowth of forage and seed 

production and use after May 15 reduced forage and seed 

production even further. Early and late spring grazing 

results in essentially no seed production. In order to maintain vigorous plants of drought tolerant alfalfa cultivars, it 

is recommended that spring grazing by livestock should not 

extend beyond May 15 and not occur in consecutive years. 

Acknowledgments 

Funds were provided through Federal Aid in Wildlife 

Restoration Project W82R, Study 8 and Rocky Mountain 

Research Station, Forest Service, U.S. Department of Agriculture, Provo, Utah. 

354 

References _________ _ 

Kilcher, M. R; Heinrich, D. H. 1965. Persistence of alfalfa in 

mixtures wi th grasses in a semiarid region. Canadian Journal of 

Plant Science. 46:163-167. 

Rosenstock. S. S.; Stevens, R. 1989. Herbivore effects on seeded 

alfalfa at four pinyon-juniper sites in central Utah. Journal of 

Range Management. 42(6):483-490. 

Rumbaugh, M. D. 1982. Reseeding by eight alfalfas populations in 

a semiarid pasture. Journal of Range Management. 35:84-86. 

Rumbaugh, M. D.; Townsend, C. E. 1985. Range legume selection 

and breeding in North America. In: McArthur, E. D.; Carlson, J. 

R, eds. Proceedings selected papers presented at the 38th annual 

meeting of the Society for Range Management; 1985 Feb. 11-15, 

Salt Lake City, UT. Denver, CO: Society for Range Management. 

137-147. 

Stevens, R; Monsen, S. B. In press. Alfalfa. In: Monsen, S. B; 

Stevens, R, eds. Restoration and revegetation of western ranges 

and wildlands. Rocky Mountain Research Station, Gen. Tech. 

Report. 

U.S. Department of Agriculture. 1971. Management and use of 

alfalfa. In: Conservation Plant Handbook. Washington, DC: U.S. 

Department of Agriculture, Soil Conservation Service. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Management 

Implications 

Ecology and Management of Pinyon-Juniper 

Communities Within the Interior West: 

Overview of the "Management Implications 

Session" of the Symposium 

Mike Pellant 

Abstract-Categories of papers in the "Management Implications 

Session" were (1) ecological guidelines and thresholds, (2) collaboration, (3) rehabitation after wildfire, (4) weed management, and (5) 

miscellaneous management topics. The application of science, experience, and collaboration is a necessity for properly managing these 

diverse and ecologically complex ecosystems. Failure to undertake 

this task could result in woodland landscapes dominated by weeds 

and frequent and intense disturbance events. 

A number of interesting and effective management strategies for pinyon pine (Pinus spp.) and/or juniper (Juniperus 

spp.) woodlands (hereafter referred to generically as woodlands) were presented in the "Management Implications" 

session of this symposium. I have attempted to synthesize 

the salient and innovative points from the 14 papers that 

were prepared for these proceedings. I also included one 

abstract in this synthesis from a symposium presenter who 

did not prepare a paper for these proceedings. This synthesis 

is a brief summary, and the reader is encouraged to review 

the individual papers cited for more detailed information. 

Finally, this review is couched by my experiences managing 

woodlands for the Bureau of Land Management (BLM) in 

southeastern Utah in the late 1970's. 

Management of woodlands is affected by a wide variety of 

natural and anthropogenic influences. Management decisions must be considered in a scientific and political framework to implement management prescriptions effectively 

and to obtain a desired outcome. These decisions are based 

upon the land manager's experience and available science 

related to woodland management. Due to information gaps 

on some aspects of the ecology and restoration, woodlands 

management has been more of an "art" and less of a "science." These proceedings certainly provide much needed 

information (such as science and practical experience) to 

improve woodland management. 

I have organized the papers in the "Management Implications" section into the following categories to facilitate their 

synthesis: 

1. Ecological Guidelines and Thresholds 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.s. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Mike Pellant is Rangeland Ecologist, Bureau of Land Management, Idaho 

State Office, 1387 S. Vinnell Way, Boise, ID 83709. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

2. Collaboration 

3. Rehabilitation After Wildfire 

4. Weed Management 

5. Miscellaneous Management Topics 

Ecological Guidelines and 

Thresholds _________ _ 

The five papers in this section provide managers with the 

framework to incorporate community ecology and the new 

"state and transition models" in developing and implementing management strategies forwoodlands. All authors agree 

that woodlands are ecologically complex and vary greatly 

both spatially and temporally. Incorporation of science and 

research into management decisions is essential if resource 

issues and political controversy associated with woodlands 

are to be resolved. 

Benchmarks or reference areas are one of the cornerstones 

to sound management of rangelands and woodlands. Miller 

and others described characteristics and val ues of old growth 

juniper and pinyon woodlands. Old growth woodlands are 

characterized by pre settlement trees (established prior to 

1870), which are typically present in open stands with 

understory species. Managers can benefit by recognizing 

and maintaining these woodlands given the diversity of 

plant and wildlife species that inhabit these areas and the 

recreational, cultural, and spiritual opportunities they offer. 

The authors recommended conducting inventories to identify and describe old growth woodlands and to closely evaluate fire suppression and prescribe fire policies in these areas. 

Eddleman concurred with the previous assertion that a 

serious limitation in management of woodlands is the lack of 

information from benchmark or reference areas and inadequate research on postsettlement woodlands. He provided 

the following guidelines for the "ecological" management of 

woodlands: 

1. Establish clear management goals and objectives. 

2. Identify ecological problems on the area under consideration. 

3. Inventory (tree age classes, understory vegetation, and 

ecological or functional status). 

4. Evaluate landscape conditions around the area under 

consideration. 

5. Implement management and restoration activities. 

I would add a sixth element to this list, "Monitor and adjust 

management accordingly." It is also important to obtain and 

share information on the success or failure of management 

or restoration activities in meeting goals and objectives. 

357 
Tausch related the concepts of transitions and thresholds 

to the management of woodlands. He defined a threshold as 

"a significant change in the species composition or functioning of the community found on a site that usually results 

from some level of disturbance." A transition is the process 

of crossing a generally irreversible community threshold 

that is permanent unless major management actions are 

taken or a significant natural disturbance occurs. 

It is important for managers to recognize thresholds and 

transitions in woodland management. Examples of "crossed" 

thresholds included sagebrush steppe vegetation that is 

invaded by and eventually dominated by woodland trees or 

sites where cheatgrass (Bromus tectorum) invades and dominates woodland sites following wildfires. Managers also 

need to be aware of the potential for certain plant associations to decrease and reach "dormant" thresholds. The 

threshold may be crossed following a disturbance (such as 

cheatgrass existing in the understory of woodlands susceptible to wildfires). There is also a spatial aspect to thresholds 

that must be considered in management. A disturbance in a 

surrounding area may influence or even "push" a nearby site 

over a threshold. For example, erosion and weed invasion 

after a woodland wildfire may impact surrounding areas 

causing them to become more susceptible to degradation 

after future disturbances. 

Managers should recognize when a threshold is being 

approached for a woodland landscape unit and decide what, 

if any, management actions are required to reduce the 

probability of the threshold being crossed. The invasion of 

sagebrush steppe communities by juniper trees is an example of a plant community transition that will eventually 

result in a closed canopy woodland if management actions 

(such as prescribed fire) are not applied in a timely manner. 

If this threshold is crossed, accelerated erosion may occur, 

and the site potential may be changed to a degree that sagebrush steppe vegetation may no longer be adapted to the site. 

Restoration activities-including woodland manipulations 

(chaining, burning, thinning, and so forth) and seedings 

with introduced species-shoul.d also be evaluated for transitions and thresholds. Such manipulations may meet shortterm management objectives such as increased forage for 

herbivores, but they may also prove to be ecologically unsound. We need a better understanding of thresholds and 

transitions to implement appropriate management for almost all woodlands. 

Miller and others described the threshold that is crossed 

as shrub steppe vegetation converted to ajuniperwoodland. 

Early indicators of such a conversion are the reduction in 

leader growth on dominant and understory trees and the loss 

of vigor and mortality of shrubs near large j uni per trees. Once 

this threshold is crossed, fire potential is reduced, and loss of 

native species and accelerated erosion generally increases. 

On low elevation rangelands (below 5,000 ft) exotic annual 

grasses, principally cheatgrass, may increase with poor 

livestock grazing management in juniper woodlands. It is 

essential that managers recognize the resource management implications of crossing this threshold and apply 

treatments to check the conversion in a timely manner. All 

of these actions must be considered in the context of the 

spatial and temporal heterogeneity that exists in woodlands 

across the landscape as well as the political, environmental, 

and budgetary issues influencing their management. 

358 

In the final paper in this section, Goodrich and Barber 

1999 discuss the return interval for pinyon pine (Pinus 

edulis Engelm.) and Utah juniper (Juniperus osteosperma 

[Torr.] Little) following several wildfires that occurred about 

100 years ago in northeastern Utah. They found a slow 

return rate of pinyon pine and Utah juniper for the first 40 

to 50 years following the fires with an accelerated return 

rate thereafter. An estimated 150 to 200 years would be 

required to achieve preburn tree density for the Green River 

corridor of Utah. Therefore, a relatively small annual burning program would result in an adequate mix of sera 1 stages 

on the landscape given this long woodland recovery period 

after fire. 

Collaboration ________ _ 

Management of woodlands is becoming a controversial 

and contentious issue. Environmental groups are challenging management actions, especially chaining, on these woodlands. Concerns over the past management practice oflarge 

"block" chainings and reseeding introduced grasses has 

caused a heightened concern about any management action 

that results in a loss of woodlands. 

Nelson and others described a collaborative process that 

was successfully used to implement chaining and seeding of 

pinyon-juniper woodlands in Spanish Fork Canyon, Utah. 

Early public participation in the planning process, clear and 

simple objectives, good interagency cooperation combined 

with nonagency partnerships, and follow-up monitoring all 

contributed to the successful chaining and seeding of small 

tracts of pinyon-juniper woodlands. 

Goodloe described the value of integrated resource management in his paper in the "Restoration" session of this 

proceedings. He applied holistic livestock management and 

reintroduced fire on his ranch in New Mexico to reverse the 

effects of80 years of fire suppression and year-long grazing 

responsible for the conversion of productive grassland communities to woodland species. He first thinned the tree 

stands and sold the wood as fenceposts, fuel wood, and 

Christmas trees. This treatment was followed by prescribed 

fire and reseeding with native grasses. Rotation livestock 

grazing systems now maintain these restored plant communities, which benefits livestock, wildlife, and recreation 

users, and stabilizes watershed values. 

Native Americans also value and rely on the products from 

woodlands, and Miller reminds us that deeply rooted traditional values are associated with woodlands by various 

tribes. His agency (Bureau ofIndian Affairs) is working with 

the tribes to manage these woodlands in a sustainable 

manner guided by tribal culture and tradition. 

Rehabilitation After Wildfire __ _ 

Two papers addressed rehabilitation efforts by the Bureau of Land Management (BLM) after wildfires in woodlands. Roberts described the financial and ecological impacts on public lands caused by the increasing frequency of 

woodland wildfires. In 1996, Utah BLM implemented nearly 

$9 million of rehabilitation projects on burned range and 

woodlands. Roberts identifies cheatgrass as the primary 

cause of the increased fire frequency. He is also concerned 

USDA Forest Service Proceedings RMRS-P-9. 1999 
about the potential for other even more pervasive noxious 

weeds moving into these woodlands after wildfires. 

MacDonald described the initial results of rehabilitation 

practices applied in 1996 on 102,100 acres of burned woodlands in south-central Utah. Aerial seeding followed by oneway anchor chaining resulted in better seeded species establishment than aerial seeding with no cover. Anchor chaining 

to cover seeds was controversial, yet the preliminary study 

results clearly demonstrate the value of seed coverage in 

ensuring that seeded species are successfully established. 

The need for rehabilitation of woodlands will accelerate in 

the future given the increase of cheatgrass (and thus wildfires) in the understory or on the periphery of Western 

woodlands. Managers must give more consideration to the 

concept of thresholds in planning rehabilitation practices, 

especially in deciding whether to seed or allow natural 

recovery to occur, what seed mix to use (native, introduced, 

or a combination), and where seeding is necessary. The 

short-term and long-term trajectories of post fire plant communities, including weeds, will be greatly influenced by the 

decisions made during the rehabilitation planning process. 

Weed Management 

The role of cheatgrass and other weeds in the management of pinyon or juniper woodlands is the focus of the 

majority of the papers in this section. Two papers dealt with 

weed potential problems in planning woodland treatments 

and management of weeds before and after seeding. Svejcar 

cautions managers against automatically assuming that 

just because a weed is present, it will dominate the site if 

woodland species are removed. The response of weeds in 

woodland conversion projects is site specific and governed by 

the pretreatment plant community, susceptibility ofthe site 

to weed encroachment, and posttreatment management 

actions and climate. Svejcar suggests six steps to consider 

when planning any woodland conversion project and calls 

for the development of state and transition models to assist 

managers in making better decisions. 

Goodrich and Rooks evaluated the effectiveness of a postfire 

seeding in reducing dominance of cheatgrass and musk 

thistle (Carduus nutans L.). They described the weed infestation that occurred after the 1976 wildfire in a pinyonjuniper woodland in northeastern Utah. Subsequently, a 

portion of the 1976 burn area was burned again in 1990 to 

reduce cheatgrass and reseeded to introduced grasses to 

compete with weeds that dominated the site after the original burn. The nonseeded area had 10 times more musk 

thistle plants than did the seeded area 6 years after the 

prescribed burn and seed treatment Cheatgrass frequency 

and vigor were also reduced in the seeding compared to the 

unseeded area. 

Goodrich and Rooks also addressed the seeding of natives 

versus selected introduced species to exclude weeds in disturbed pinyon-juniper woodlands. They contend that until 

availability of native plant materials improves, competitive 

introduced species should be planted to prevent establishment and dominance of cheatgrass or other weeds after 

woodland treatments. They further caution against requiring only the use of "local natives" on large-scale restoration 

projects because costs and availability of seed could be too 

restrictive. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

The potential for weed expansion after disturbance in 

many woodlands is high and should be a concern for managers. Early detection, aggressive treatment, and monitoring 

are a few of the required steps to minimize this threat to the 

integrity of Western woodlands. This task is one of the most 

challenging in regards to woodland management and will 

increase as disturbances such as wildland fires continue to 

increase and weeds adapt and evolve to new environments. 

Miscellaneous Management 

Topics ___________ _ 

Three presentations provided valuable information on the 

management of woodlands but did not logically fit into the 

previous organization or new categories. Rasmussen and 

others proposed the use of a helitorch to burn pinyon or 

juniper that has encroached in riparian areas. They speculate that if the treatment were done in the spring, and if the 

trees were individually ignited, then successful, albeit expensive, control could be obtained. Given the high resource 

values associated with riparian areas, further research or 

tests on this technique are warranted. 

Stevens and others examined the effects of livestock 

grazing on dryland alfalfa planted in several woodland 

conversion projects near Ephraim, UT. Annual grazing after 

May 15 resulted in little alfalfa regrowth or seed production. 

Loss of alfalfa in the stand eventually occurred, reducing the 

diversity and forage value of the seedings. This study demonstrates the importance of considering short-term and 

long-term effects of livestock and wildlife grazing in the 

management of multispecies see dings after woodland conversion projects. 

Eager described increasing mortality of pinyon pine 

throughout western Colorado and proposed some management actions to reduce these losses. Insect infestations and 

fungal root disease are the primary cause of the increased 

pinyon pine mortality. Human activity, primarily road, 

fence, and home construction, can cause tree damage by 

allowing the entry of insects or disease. Managers can 

minimize these outbreaks by scheduling disturbance treatments in cool weather and by promptly removing damaged 

trees or stumps from work areas. 

Summary 

These "Management Implications" papers all contribute 

to a better understanding of opportuni ties and constraints in 

managing Western woodlands. Managers should become 

more knowledgeable of the concepts of thresholds and the 

ecological implications of management actions they initiate 

or even the management actions that they don't take. Prescribed fire, chaining, and thinning are just a few of the 

woodland conversion tools that could be used to meet specific 

land use or management objectives. However, these treatments in conjunction with climate, livestock management, 

or weed invasion may "push" treatment areas across thresholds that mayor may not be compatible with long-term 

management objectives (fig. 1). 

Management in woodlands, especially controversial treatments such as chaining or seeding with nonnative plants, 

must be done collaboratively to minimize conflict and to 

359 
Figure 1-Utah juniper is invading a historical sagebrush steppe plant community that is now 

dominated by cheatgrass. A recent wildfire has burned into the area invaded by the juniper. 

Other noxious weeds are in the vicinity and have the potential to invade this disturbed site. 

What are the management implications and options in this situation? 

ensure that decisions are made by stakeholders and not by 

our judicial system. Native Americans have many utilitarian and spiritual ties to woodlands that also need to be 

considered in any management strategy. 

Wildfires have increased gr~atly in frequency and extent 

in certain areas dominated by woodlands in recent years. 

Rehabilitation after woodland fires is often necessary to 

prevent accelerated erosion and entry of invasive plants. 

Where seeding is required, every effort should be made to 

cover the seed mechanically to enhance the successful establishment of all seeded species. Rehabilitation planning should 

include an analysis of the potential thresholds that may be 

crossed given the practices proposed. Postfire livestock grazing, seeding with aggressive nonnative grasses, and not 

controlling noxious weeds all have the potential individually 

or in combination after fire to direct succession across a 

threshold to a new, undesirable stable state. 

Perhaps the greatest threat to Western woodlands is the 

spread of weeds both invasive weeds (such as cheatgrass) 

and noxious weeds. Woodland treatment plans must include 

an evaluation of weed invasion potential in the posttreat360 

ment environment but not to the point where unfounded fear 

of a potential weed invasion precludes any manipulation or 

change in the management of woodlands. Where weeds are 

a threat after woodland disturbance, seeding competitive 

introduced grasses could reduce the threat. However, a 

better long-term goal is to increase the supply and availability of native plant materials that can both compete with 

weeds and provide the diversity and function of the historical woodland communities. 

Implications of our actions, or lack of action, in managing 

woodlands may affect the Western landscape far into the 

future. The application of science, experience, and collaboration is a necessity for properly managing these diverse and 

ecologically complex ecosystems. Applied research, monitoring of management actions, and the sharing oflocal knowledge, information, and successes, as well as failures, are all 

critical for improving the understanding and proper management of Western woodlands. Ifwe fail in this undertaking, woodland landscapes dominated by weeds and frequent 

and intense disturbance events may become an unwanted 

reality. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Transitions and Thresholds: Influences and 

Implications for Management in Pinyon and 

Juniper Woodlands 

Robin J. Tausch 

Abstract-Thresholds are important to understanding Great Basin ecology. Once a threshold has been crossed, the new community 

may have very different functional capabilities than the previous 

comm uni ty. Managemen t action needs to occur well before a threshold is crossed to be effective, and that action needs to reflect the 

scales oftime and space in which the affected ecosystems and their 

thresholds function. Great Basin woodlands have at least three 

categories of thresholds, with two stages in the threshold process. 

The three categories of threshold differ in both the duration and 

timing by which the two stages of the threshold process occur. 

Depending on the community, more than one threshold may be 

involved in affecting community change at the same time. Thresholds interact between communities on landscape scales over the 

long term, often in response to climate change, and are most 

effectively managed on a landscape basis. 

One of the most important aspects in understanding 

Great Basin pinyon-juniper woodland ecology is the concept 

of a threshold. The basic description of a threshold is a 

significant change in the species composition or functioning 

of the community found on a site that usually results from 

some level of disturbance. In the majority of instances , once 

the change has occurred returning the community back 

across the threshold may be very difficult or impossible 

(Laycock 1991; Tausch and others 1993; Westoby and others 

1989). The community that is present after the threshold 

has been crossed is usually a new community that could 

have different functional capabilities than the previous 

community. 

Ifa threshold is crossed managers must recognize, evaluate, and manage the new community based on its new range 

of functional possibilities (Tausch 1996). They also need to 

look at thresholds and their outcomes in time scales appropriate to ecosystems involved (Millar 1997). Techniques 

need to be developed to make it possible to recognize when 

a threshold is being approached well before it is crossedwhen some form of corrective action may still possible to 

avoid the coming changes. 

The prevailing climate is the primary influence on the 

ecosystem distribution and dynamics of a region (Betancourt 

and others 1993; Bailey and others 1994). Climate, its 

changes, and its modification by landform, probably plays 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Robin J. Tausch is Project Leader, Rocky Mountain Research Station, 920 

Valley Road, Reno, NV 89512. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

major roles in the development and activation of thresholds. 

Climate and communities have interactions, including 

thresholds, that occur at many spatial and temporal scales. 

In response to the past climate changes Great Basin 

vegetation has had repeated changes (Nowak and others 

1994a,b; Thompson 1990), many probably involving thresholds. The dynamic and individualistic responses to climate 

change by plant species (Tausch and others 1993) may be 

involved in the existence and outcomes of thresholds. The 

threshold concept needs clarification and expansion in its 

application to pinyon-juniper woodland ecology. Such application of the threshold concept needs to better reflect the 

scales of time and space and associated changes in which 

ecosystems function. Most examples of thresholds published 

(Laycock 1991; Tausch and others 1993; Westoby and others 

1989) focus mostly on the biotic aspects of the changes to 

vegetation that result from chronic disturbances. Abiotic 

changes that are discussed are generally those that are 

eviden t after the vegeta tion has been pushed across a threshold. An expanded view is that thresholds can have both 

abiotic and biotic aspects, with varying levels of interaction 

between them. 

Thresholds in Great Basin 

Vegetation 

For the woodlands of the Great Basin, there are at least 

three categories of thresholds that can be described. There 

are also two stages to the process for each of the threshold 

categories: (1) crossed or set, and (2) activated. There is also 

a quasi third stage (dormant) that can precede any of the 

three categories. The three categories, two stages, and one 

quasi category will be explained through the use of 

examples. 

The first category of thresholds is brought about by some 

form of chronic impact that pushes the vegetation through a 

series of changes. At some point in those vegetation changes, 

and in the associated abiotic changes, a threshold is crossed. 

An analogous description is that the community is first bent 

until it is right at the edge of the breaking point. Then with 

one last push, it finally breaks. The vegetation description is 

that the changes resulting from an impact reaches a point 

where a threshold is first set, then activated, with the final 

vegetation changes immediately following. Here, the setting 

of the threshold, and its activation, occur almost simultaneously and is the type of threshold that has been most 

commonly recognized and discussed. This first threshold 

category has the criteria that a community has crossed a 

threshold only when the vegetation changes involved have 

361 
largely, or entirely occurred. While this category of thresholds is present and important in the Great Basin, others are 

also present. 

The second category ofthresholds results from changes in 

a community that are subtle and not always obvious. These 

thresholds are often abiotically driven, but biotic factors 

may be involved. The change in composition that has occurred has its affect on the outcome of a disturbance. This 

threshold can be crossed without a major readily visible 

vegetation change immediately occurring. The vegetation 

change that has occurred has resulted in a community that 

I am defining as "set". The final vegetation change will occur 

after there has been some form of major disturbance, which 

is the trigger that activates the final vegetation change. 

Although a community can appear to be unchanged without close examination, it is the type or the outcome of a 

disturbance, such as fire, that has -been changed. The 

successional processes that follow the disturbance will involve new post-disturbance successional trajectories. The 

alteration of the community and its successional patterns 

may also result in the possibility of yet new forms ofdisturbance in the future. For this category, subtle changes in the 

initial floristics of a site that occur well before a disturbance 

may have the effect of both generating or setting a threshold 

and pushing the community across it. Final activation, 

however, only occurs after a disturbance. 

A good example of this second category of threshold is the 

invasion of cheatgrass into a woodland site. Woodland dynamics largely remain unchanged, even with cheatgrass in 

the community, as long as there is no fire. However, if the 

site becomes dominated by cheatgrass and other annuals 

following the fire, then a threshold was crossed with the 

cheatgrass invasion. Following fire the woodland may have 

been lost, which is a very different outcome than would have 

occurred without the presence of cheatgrass. 

The invasion or establishment of any new species into a 

community often involves the potential for new thresholds, 

particularly when they develop a dominant position in the 

community. A threshold should be considered to be present, 

and to have been crossed, whenever the amount of time 

passing between its being set or crossed, and its activation 

by a disturbance, does not change the outcome. Many Great 

Basin communities have probably already crossed such a 

threshold, but the full affect of introduced or other species 

that are responsible is as yet unknown. The outcomes of 

these introductions on the generation and activation of new 

thresholds can be expected to play out for some time. 

The third category of thresholds recognizable in Great 

Basin woodlands is actually quite common, but these thresholds are even more infrequently recognized as such. For this 

category, there is some combination of biotic and abiotic 

factors that both set, and then activated, the threshold. The 

vegetation change that results is a permanent alteration in 

the successional dynamics of the community. However, this 

activation phase may take decades to reach completion. The 

alteration of the successional dynamics activates the progression to a new community. This type of permanent 

change in the successional trajectory of a community should 

be considered just as much the crossingofa threshold as the 

other examples, even though it may take a century or more 

for the full change of the activation stage to manifest itself. 

362 

The third category of threshold has similarities to the first 

category; the main exception is that the activation phase 

takes much longer. They may possibly represent opposite 

ends of a sort of a gradient of activation patterns and rates. 

The majority of the woodlands in the Great Basin may 

have already crossed a threshold in this third category. In 

the late 19th century, at the end of the Little Ice Age, a series 

of changes occurred that generated an example of this 

threshold. Four of these changes were a reduction in fire 

frequencies (Gruell, this proceedings), heavy livestock grazing, the increase in atmospheric CO2 (Farquhar 1997; Polley 

and others 1996; Tausch and others 1993) and a changing 

climate since the end of the Little Ice Age (Chambers and 

others 1998; Woolfenden 1996). Whatever the interaction of 

these factors, and any others that may have been involved, 

the majority of the potential woodland area in the Great 

Basin crossed a category three threshold. The outcome of 

this threshold has been the dramatic increase in the area 

and dominance of pinyon-juniper woodlands that has been 

progressing largely unrestricted over the last 150 years. 

Abiotic conditions and associated patterns of disturbance 

and succession that prevented this in the past are gone. 

Both the second and third category thresholds may also be 

generated by the loss of key species. An example would be 

the loss of species of mycorrhizal fungi usually associated 

with a shrub-grass dominated community from increasing 

tree dominance, possibly in combination with crown fire 

(Klopatek and others 1988). 

There is one more quasi stage, or possibly a fourth category, of proto or dormant threshold. This is a threshold that 

does not yet exist but most of the required precursors are in 

place, and if certain future dynamics occur, the threshold 

could potentially develop the remaining precursors to be set 

or crossed, and activated. History shows us that each change 

in vegetation sets up the conditions that interact with 

environmental changes to eventually trigger the next set of 

vegetation changes (Tausch, this proceedings). The examples 

of the woodland expansion, the introduction of annuals, and 

ongoing climate change described are causing community 

changes that are setting up the conditions for the eventual 

development of additional new thresholds. The potential for 

there to be new community patterns after these thresholds 

are crossed is high, particularly where exotic annuals are 

involved. 

A community dominated by exotic annuals is essentially 

an open or unstable community waiting for the next invader. 

This is an example that represents a dormant threshold that 

cannot be generated, or set and activated, until after the 

arrival of the next species capable ofinvading the site. This 

invasion will happen, we just do not know when or what the 

species or the outcome will be until it happens. The community changes associated with the dominance of annuals is 

also leading to unknown changes in nutrient cycles and 

microbial processes for the sites and communities involved 

(Klopatek and others 1988). These soil changes could also 

contribute to the future development of new thresholds. 

A second example of a dormant threshold is also present 

in many of the current woodlands that crossed the third 

category of threshold at the end of the Little ice Age. The 

altered successional changes that resulted are moving the 

woodlands toward yet another threshold. As larger and 

USDA Forest Service Proceedings RMRS-P-9. 1999 
larger areas of these woodlands reach the point of crown 

closure, thereby becoming susceptible to catastrophic crown 

fire, they will have reached and then crossed a second 

formerly dormant category two threshold. The permanent 

vegetation changes will then wait only for the disturbance. 

There appear to be two general ways environmental 

influences can bring any of these thresholds into existencedirect and indirect. The direct effects are most commonly 

reported in the literature and are usually involved with the 

first category of threshold. A disturbance directly impacts 

the vegetation, and the changes brought about pushes the 

community toward, and finally over, the threshold. Direct 

effects can work through biotic or abiotic mechanisms, may 

or may not be the final trigger activating the vegetation 

change. 

Indirect effects appear to usually result from abiotic 

changes. An example of indirect effects is the fertilization 

effects of increasing atmospheric CO2 and the differing 

responses to this increase between plant species (Farquhar 

1997; Polley and others 1996). In many communities this 

indirect effect represents at least the presence of possible 

dormant thresholds. We do not know how each community 

is being affected, what thresholds are pending or already 

crossed, and what the resulting vegetation changes will be. 

More than one threshold can also be involved at one time. 

As previously explained, Great Basin woodlands crossed a 

third category threshold in the late 19th century. The activation stage of that threshold is still underway. On some sites 

there has been the introduction of cheatgrass, which has 

taken these sites across the second category of threshold. As 

the successional processes from the activation stage of the 

first threshold run their course, the dormant biotic threshold of susceptibility to catastrophic crown fire will be reached 

and set. When the next activation stage is triggered by fire, 

the outcome will be much different for many sites than ifthe 

cheatgrass were absent. Unless something changes the 

communities to alter those trajectories of change and their 

associated thresholds, the final activation by fire and conversion to an annual-dominated community will only be a 

matter of time. 

Scale-related factors are important in defining ecosystem 

boundaries and the associated development and outcomes of 

thresholds. Interaction between regional and local scale 

topography, soils, associated species, environmental conditions, and disturbance types and frequencies can also cause 

major changes in the way sites respond to a disturbance, and 

thus affect both the presence and outcomes ofthresholds. At 

each level in the nested structure of Great Basin ecosystems, 

a different aspect of climate and vegetation can be important 

in the development of thresholds. 

How any system responds to the development and activation of thresholds is also at least partially related to how it 

interacts with surrounding systems. Changes occurring in 

other communities in the area around a particular community can result in the generation of a threshold, even if that 

community has had no change, for example a woodland on a 

steep slope with shallow soils. When the community on an 

adjacent site with deeper soils was non tree-dominated, fire 

intensity was insufficient to carry up through the woodland. 

If the adjacent community becomes tree-dominated, the 

heat generated by the next fire will be sufficient for the fire 

to carry up through the woodland on the adjacent slope. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Because of the environmental and topographic heterogeneity of the Great Basin, communities generally do not 

develop toward new thresholds at the same rate across a 

landscape. The thresholds that develop can differ from 

location to location, which may help prevent the simultaneous occurrence of the same change over a large area. 

Over time, topographic-based site-to-site differences may 

have a tendency to break up large areas of uniform vegetation. An example of such an outcome is the high level of 

vegetation heterogeneity in chaparral in northern Baja, 

Mexico (Minnich and Chou 1997). As the areas experiencing 

a particular change become smaller, the mix of vegetation 

types and their associated successional stages may become 

more heterogenous over the landscape. The intermixing and 

interfingering of the mix of communities and associated 

successional stages that can develop increases landscape 

complexity. One way of describing it would be a dynamic 

fractal-like distribution across the landscape that is constantly changing. The outcome of thresholds becomes spatially more limited. 

The pattern through history is that some environmental 

conditions seem to increase the development of landscape 

heterogeneity or complexity, and others seem to decrease it. 

There is an apparent shifting back and forth between community patterns of uniformity, or of more complexity. There 

appears to be some relationship between the types of community patterns present, the types and severity of the 

climatic changes, the associated disturbances involved, and 

the level of heterogeneity or homogeneity. 

Management Implications 

We know from history that the processes of change always 

continue through time (Nowak and others 1994a,b; Tausch 

and others 1993; Woolfenden 1996). Any of these changes in 

conditions can introduce new thresholds. Ecosystem management is the management of these changes and their 

associated thresholds as they are mixed over the landscape. 

Through management actions, we can slow or accelerate the 

trajectories of change, we can alter their direction, sometimes even reverse them, but we can never stop them. Every 

alteration we make, however, will affect the type, timing, 

magnitude, interaction, and outcome of future thresholds. 

The more effectively we can anticipate these changes resulting from our actions, the more effective ecosystem management will be. 

If vegetation that has crossed a second or third category 

of threshold is not altered by direct intervention to change 

its structure or composition, the activation of the threshold 

by a disturbance will only be a matter of time. It will be 

desirable to attempt to treat some of these areas to possibly 

alter the outcome, which mayor may not be easier to do 

before the activation stage has occurred. These treatments 

should be done based on the conditions existing on the entire 

associated landscape to maintain the diversity of the community, its successional stages, and their interconnectedness, and to help avoid the establishment of new, unwanted 

thresholds. The treatments used must incorporate the biological, topographic, and edaphic heterogeneity of the sites 

involved into their application. This is to preserve, and to 

take advantage of, the existing diversity-both biotic and 

abiotic. 

363 
Most of the existing treatments that have occurred so far 

in Great Basin woodlands have been, at least indirectly, and 

even if unknowingly, attempting to prevent the activation 

of, or alter the existence of, one or more of the described 

thresholds. Most the these treatments, such as chaining, 

have tended to ignore the biological, topographic, and edaphic 

heterogeneity of the treated sites. Usually they have been 

based more on a plowed-field type of model in their application. Large blocks have been treated as uniformly as possible 

over their entirety. Either no place within the treatment 

area is left unaffected, or a few token untreated islands are 

left isolated within the treatment. Also, on most of the acres 

that have been treated, the results are often inadequate. 

These treatments have sometimes provided a short-term 

slowing of the generation or activation of the targeted 

threshold. They have largely not changed the final outcome 

because they have not been based on-the dynamics of the 

target communities and their thresholds. 

The current level of uniformity over many areas of Great 

Basin woodlands may be one of the highest of the Holocene 

(Tausch, this proceedings). This uniformity appears to be 

the result of human activities over the last century and a half 

that have interacted with climate change to contribute to the 

simplification and homogenization of the landscape. It is 

basically the same outcome as observed in southern California chaparral where management activities have greatly 

increased their homogeneity in comparison to the chaparral 

across the border in northern Baja, Mexico (Minnich and 

Chou 1997). This homogenization has resulted from several 

impacts, including the introduction of exotic annuals, the 

many types of natural resource utilization patterns, fire 

suppression efforts, and the related increasing dominance of 

woody species. The increasing CO2 content of the atmosphere, and atmospheric input of nitrogen into the system 

from air pollution, could also be contributing components. 

Such simplified, homogenized systems can be prone to the 

development of new thresholds. These thresholds can precipitate major vegetation and system changes that are new, 

or unique, to the ecosystems and species affected. Because 

of the homogeneity the changes can affect large areas 

simultaneously. 

Past management activities have tended to apply similar 

procedures across the landscape on a piecemeal basis without adequate consideration oflandscape variability or longterm consequences. As in other regions, this narrow focus 

has often contributed to ecosystem homogenization over 

large areas of the Great Basin. Such piecemeal management 

has also tended to have limited long-term success. Correcting these problems will require closer observation within the 

context of the greater temporal and spatial scales within 

which each site is imbedded. Unless such landscape level 

dynamics. and their long-term changes and interactions 

with thresholds, are a part of future ecosystem management, success will remain limited. 

Identification of the controlling environmental factors is 

necessary to manage thresholds on the basis of landscapelevel interactions over the long-term. For the Great Basin, 

much of the needed information on factors controlling community dynamics is absent. Additionally, different combinations of controlling factors can, in different locations, result 

in similar- appearing vegetation communities. These communities may have different thresholds and may respond 

364 

differently to the same management or disturbance despite 

their similar appearance. Because our knowledge of causes 

is limited, we have often been left with only descriptions of 

the differences these causes have produced (Bailey and 

others 1994). The need to move beyond describing the 

outcomes after they have occurred, to being able to anticipate future changes, is probably our greatest challenge. 

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Ecoregions and subregions of the United States. Map (scale 

1:7,500,000). Washington, D.C: U. S. Department of Agriculture, 

Forest Service. 

Betancourt, J. L.; Pierson, E. A; Rylander, K. A.; Fairchild-Parks, 

J. A; Dean, J. S. 1993. Influence of history and climate on New 

Mexico pinon-juniper woodlands. In: Aldon, E. F.; Shaw, D. W., 

coords. Proceedings, managing pinon-juniper ecosystems for 

sustainability and social needs; 1993 April 26-30; Santa Fe, NM. 

Gen. Tech. Rep. RM-GTR-236. Fort Collins, CO: U.S. Department 

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Experiment Station: 42-62. 

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D.; Martin, D.; Nowak, C. 1998. Understanding long- and shortterm changes in vegetation and geomorphic processes: the key to 

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simulated fire on vesicular- arbuscular mycorrhizae in pinyonjuniper woodland soil. Plant and Soil. 109: 245-249. 

Laycock, W. A 1991. Stable states and thresholds ofrange condition 

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Management. 44: 427-433. 

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the chaparral of southern California and northern Baja California. International Journal of Wildland Fire. 7: 221-248. 

Millar, C. 1. 1997. Comments on historical variation and desired 

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Nowak, C. L.; Nowak, R. S.; Tausch, R. J.; Wigand, P. E.1994a. Tree 

and shrub dynamics in northwestern Great Basin woodland and 

shrub steppe during the late-Pleistocene and Holocene. American 

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Nowak, C. L.; Nowak, R. S.; Tausch, R. J.; and Wigand, P. E. 1994b. 

A 30,000 year record of vegetation dynamics at a semi-arid locale 

in the Great Basin. Journal of Vegetation Science. 5: 579-590. 

Polley, H. W.; Johnson, H. B.; Mayeux, H. S.; Tischler, C. R. 1996. 

Impacts of rising CO2 concentration on water use efficiency of 

woody grassland invaders. In: Barrow, J. R.; McArthur, E. D.; 

Sosebee, R. E.; Tausch, R. J., comps. 1996. Proceedings: shrubland ecosystem dynamics in a changing environment; 1995 May 

23-25; Las Cruces, NM. Gen. Tech. Rep. INT-GTR-338. Ogden, 

UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 189-194. 

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the assessment of community and ecosystem condition. In: 

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plant community thresholds, multiple steady states, and multiple successional pathways: legacy of the Quaternary? Journal of 

Range Management. 46: 439-447. 

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365 
Ecological Guidelines for Management 

and Restoration of Pinyon and Juniper 

Woodlands 

Lee E. Eddleman 

Abstract-An approach is suggested for developing general guidelines that in turn form the basis for site specific guidelines to be used 

in the management and restoration of pinyon-juniper woodlands. 

Guidelines are based on the establishment of goals, objectives and 

problem statements. This is followed by a structural and functional 

analysis ofthe land area under consideration for treatment. Finally 

a functional analysis relating the area under consideration to 

landscape as a whole is suggested. 

At the outset it must be stated that this paper is intended 

to provide guidelines suitable for the determination of ecologically based management actions on pinyon-juniper woodlands. As such it may also be adaptable to other arid and 

semi-arid systems. It is purposefully ambiguous in some 

areas to avoid the quagmire of hard and fast rules. 

Many problems arise in the development of site specific 

ecological guidelines for the management and restoration of 

pinyon-juniper woodlands. All attempts to do so are underlain by a set of assumptions that mayor may not be correct 

and are driven by expectations, desires and objectives that 

mayor may not be realistic in terms of either the supporting 

science or the available resources. Assumptions are likely 

based on social values, understanding of ecological theories 

and interpretation of ecological data, each of which need to 

keep as distinct as possible (Scarnecchia 1995 and Tausch 

1996). As yet, we do not have comprehensive, whole system, 

ecological research on our arid land areas; at best we have 

partial research on a few areas. The manager is therefore 

faced with the formidable task of formulating suitable assumptions, developing reasonable objectives and applying 

guidelines in an appropriate manner from less than adequate research data, not so succinct and frequently conflicting ecological theories, shifting social values as well as 

observations and experience. 

In spite of the lack of a comprehensive understanding 

of most arid ecosystems we are certainly not bereft of the 

basics. Ecological principles and guidelines applicable to 

the management and restoration of pinyon-juniper woodlands can be found in, or can be derived from, a variety of 

comprehensive publications including range management 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogd~n, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountam Research 

Station. 

Lee E. Eddleman is Professor of Rangeland Resources, Department of 

Rangeland Resources, Oregon State University, Corvallis, OR 97331. 

366 

(Holechek and others 1998), grazing management 

(Heitschmidt and Stuth 1991), improvement of rangelands 

(Vallentine 1989) and improvement of game ranges 

(Plummer and others 1968). More specifically, Evans (1988) 

considered many ecological relations in developing strategies for management of pinyon-juniper woodlands for a 

variety of products and values, and Aldon and others (1995) 

provides a very useful checklist of critical questions that 

should be addressed prior to initiation of any management 

scheme in the pinyon-juniper type. In the actual application 

of guidelines the manager is faced with the question: does 

the guideline fit this particular piece of land and does it fit 

in the context oflinked resource units? 

Ecological guidelines should have broad scale applicability across the main pinyon-juniper woodland as well as 

juniper woodlands of the Northwest and southern Great 

Plains. Each site, the ecological site (U.S. Department of 

Agriculture 1997), is unique within itself and it is equally 

unique in its connectivity to surrounding sites. Connectivity 

has been defined as the degree to which patches of a given 

type are joined by corridors into a lattice of nodes and links 

(Wiens and others 1993). In woodlands connectivity could be 

considered as the degree to which a site is functional linked 

to other sites or landscape units of the system. This linkage 

is both spatial and temporal and is through mechanisms of 

emigration-immigration for materials such as water, sediment, nutrients, energy, flora and fauna (Schlesinger and 

others 1990, Tongway 1990 and Wilcox and Breshears 1995). 

Site specific internal attributes and external connectivity 

attributes require not only site-specific fine filter guidelines 

but also spatially and temporally scaled guidelines. 

Establishment of guidelines for management and restoration of pinyon-juniper woodlands implies that standards 

exist and that we are capable of directing or redirecting 

ecological processes to attain those standards. Setting ecological standards is a distinctly human process and is therefore an arbitrary value judgement that shifts with shifting 

personal and societal values. We would like to think that 

pinyon-juniper woodlands have their own inherent ecological standards, and at certain temporal-spatial scales perhaps they do. Words such as natural and healthy pervade 

the literature and our concept of these words, as applied to 

a particular site, seem to provide the driving force for the 

establishment of standards. However, Lawton (1997) has 

pointed out that ecosystems change continuously at all timescales diverging more and more as we move back in time and 

Tausch (1996) points out that climate has continually changed 

in the past and it is likely to do so in the future. Lawton 

concludes that the true situation is that we have no benchmark virgin state that we can refer back to. Recognition of 

change and the processes associated with change should 

USDA Forest Service Proceedings RMRS-P-9. 1999 
allow us to formulate our site objectives and standards 

more realistically focusing on trajectories and functional 

standards (Lawton 1997, Tausch 1996). 

If the above is true, then standards and guidelines developed around concepts of sustainability should be called into 

question and carefully evaluated, particularly as to their 

spatial-temporal scale. As noted above, it also may require 

that we focus our standards and guidelines on functional 

attributes of ecosystem components rather than composition of structural components. Key functional attributes 

should be the internal attributes of the ecosystem that 

control rate and magnitude of those processes that can lead 

to degradation or visa-versa to desired conditions. At the 

same time aspects of plant composition and other surface 

structures have been found to be useful indicators of site 

function (de Soyza and others 1997). Approaches suggested 

by the Committee on Rangeland Classification (National 

Research Council 1994) are a good step toward the application offunctional ecology to determination and management 

of rangeland health and are applicable to pinyon-juniper 

woodlands. 

Guidelines 

Ecological guidelines useful in the management and restoration of pinyon-juniper woodlands have been placed to a 

degree in a question format. Questions best tend to force 

critical thinking considerably beyond the simple answers of 

yes and no and, hopefully, push responsible parties to find 

solutions from a variety of sources. Meaningful site-specific 

guidelines can be developed from a well thought out set of 

goals, objectives, problem statements, land area analyses 

and landscape analyses. 

Goals and Objectives 

Clear concise goals and objectives are required at the 

outset of any management or restorations action. Establishment of goals and objectives requires that the desired pattern and function of woodlands have been determined at 

both the landscape level and at the level of the unit of 

land, or land area, under consideration for management or 

restoration action. 

Questions that need to be asked and answered include 

those below. 

• What are the desired short-term and long-term ecological goals? 

• What are the objectives and what is the spatial-temporal 

framework for measurement? (Literally how much per 

unit of space per unit of time) 

• How do the goals for the land area under consideration 

fit within the goals for the landscape as a whole? 

• What are the assumptions that underlie each objective? 

Unless considerable thought is put into making sure 

these questions have been answered, conflicts and crosspurposes may not be identified and the reality of success 

may be illusive. Ecological goals for woodlands should include components of sustain ability, productivity and a component of conservation of natural abiotic and biotic resources. Goals and objectives must be definable, achievable 

USDA Forest Service Proceedings RMRS-P-9. 1999 

and measurable. They should provide a clear statement of 

the desired direction of change, if any, for soils, plants and 

animals, and identify desired future woodland conditions. 

The degree of success should be measurable on both temporal and spatial scales. Knowing the degree to which one's 

assumptions rely on social values, ecological theory, ecological data or observation and experience will help adjust 

confidence in reaching the goals and objectives. 

As an example, for a particular land area the manager 

may set a goal of maximizing the infiltration of precipitation 

into soil storage at all times of the year. Short-term aspects 

might be focused on normal precipitation events during the 

growing season while long-term aspects might be focused on 

abnormal hydrological events year-round. Objectives could 

include reaching a condition of zero runoff during the 

growing season from rainfall events with intensities less 

than 25 mm per hour and totals less than 13 mm in a 10 year 

period. 

Problem Statement 

The next step in the process is to state precisely and clearly 

the apparent ecological problem as it exists on the land area 

under consideration. This statement should be as comprehensive as possible and based on field observation and as 

much site-specific and local information as is available. It 

should identify structural components that control rates 

and amounts of change and processes that appear associated 

with degradation. Degradation as used in this paper is the 

degree to which pattern and process have been altered and 

the land area under consideration rendered less favorable 

for the desired plant community or communities identified 

in the goals and objectives (modified from Tongway 1990). 

As an example, a part of the problem statement may be 

that runoff is excessive as indicated by too much bare 

ground, an abundance of rills, long reaches for runoff and 

high sediment deposition on lower upland areas and drainage channels. 

Land Area Analysis _____ _ 

Kind of Woodland 

An inventory and analysis of the temporal and spatial 

nature of the woodland on the land area under consideration 

is needed since the kind of woodland presently on the land 

area determines in a large degree the management and 

restoration practices to be applied. 

Questions that need to be asking and answered include 

those below. 

• What is the age class structure of the trees? 

• What is the size class-spatial structure of the trees? 

Old woodlands have a variable number of very old trees 

present and the land area appears to have been in woodland 

for several hundreds of years. Pattern of plants, soils and 

animals, and processes, both biotic and abiotic, may appear 

spatially and temporally controlled by the tree component of 

the woodland. The tree component may appear to be stable; 

however in the last century degradation in these woodlands 

may be ongoing at several scales. Degradation may be due 

367 
to a variety of causal factors including the addition of too 

many livestock and subsequent long-term overgrazing, particularly in the spring, and the removal or deletion of fire 

from the system. 

New woodlands are those that have largely developed this 

century and there is not an indication they were previously 

present. These woodlands contain mature trees; the larger 

individuals may have recently begun to slow down their 

growth rates and mortality factors are not strongly in evidence. Patterns and processes in these communities may be 

largely under the control of the woodland. There is a relatively high probability that in many of the new woodlands 

tree densities will reach very high levels prior to mortality 

factors setting in, followed by a density decline to some lower 

level. The expansion and development of new woodlands is 

usually attributed to altered fire regimes, overgrazing by 

domestic livestock and optimal climate for establishment 

(Miller and Wigand 1994). 

Degradation in new woodland communities may be due, 

firstly, to the trees themselves. In the above scenario we 

should expect both deletions and additions of flora and 

fauna to occur as woodlands move toward high tree densities. Altering the fire regime, continued over-grazing, additions of alien plant species and perhaps extreme climatic 

events, such as the drought of the 1930s, may also be 

contributing significantly to patterns and processes in young 

woodlands. Since young woodlands have largely developed 

in the absence of fire, fire, therefore, remains an unknown 

factor in the long-term development of woodland pattern 

and process. 

Developing woodlands must also be considered as 

they are areas which are being newly invaded by trees but 

have not as yet reached the stage where pattern and process 

are dominated by trees. These future woodlands may be 

developing due to the removal offire from the existing plant 

community. Overgrazing by domestic livestock and the 

addition of alien plant species may contribute to their 

development and to various degradation processes. 

An example could be a yOll;ng woodland with a broad 

spectrum of age classes. Older trees are roughly 100 years 

old, provide a 20 percent canopy cover and number 125/ha. 

In addition, smaller trees number 50/ha. 

Understory Vegetation 

The proportions and density of understory vegetation 

components must be determined on each functional unit 

within the land area under consideration in order to predict 

possible transitions in pattern and process to potentially 

new stable states. 

Questions that need to be asked and answered include 

those below. 

• What functional groups of understory plant species are 

present and what ones are absent? 

• What plant species are missing that should be present 

and conversely what plant species are present that 

should be absent? 

• Is the apparent vigor or health of the shrub species 

sufficient to maintain them in the community or has a 

threshold been crossed and extinction expected? 

368 

• Is the density of long-lived herbaceous and shrub species 

sufficient to respond to disturbance factors, both natural and man caused? 

• What are the assumptions made in answering each 

question? 

An example could be that shrubs are sparse, live plants 

have low leaf areas and recent high mortality is evident. 

Herbaceous plants are mostly annuals made up of early 

ephemeral forbs and scattered alien grasses. Some early 

spring species of perennial bunchgrasses and tap-rooted 

forbs, as well as scattered individuals of late spring, early 

summer and fall perennial forb and grass species are present. 

All perennial plants in interspace areas are small, widely 

spaced and appear to be of low vigor. Potential response of 

the understory to management or restoration actions appears possible, but long term. 

Functional 

The land area is the local area under consideration and 

may be made up of one to several ecological sites, or one to 

several distinct functional units. The area of interest must 

be delineated to assess functional attributes. 

Questions that need to be asked and answered include 

those below. 

• What distinct ecological sites, or functioning units, are 

present? 

• What ecological factors currently dominate and control 

on-site pattern and process and how do they do so? 

• To what degree and specifically how do trees individually and collectively control on-site pattern and process? 

• What are the assumptions made to support the 

conclusions? 

• What causal factors led to current site conditions? 

• What is the degree of degradation? 

• What ecological thresholds currently restrict transitions to goal oriented ecological conditions? 

• What assumptions were made in answering each 

question? 

Thinking in spatial-temporal scales will greatly aid in 

understanding how an area functions. Spatially scaled functional units suggested by Wilcox and Breshears (1995) or 

those suggested by Tongway (1990) and Anderson and 

Hodgkinson (1997) are very useful. Temporally scaled functions should at least include key seasonal aspects of moisture input, and plant growth and reproduction. 

Woodland ecological sites may be mosaics or contain 

inclusions limited in area but significant in the functioning 

of the site at particular spatial or temporal scales. For 

example, areas of old growth trees on rock outcrops located 

within an otherwise seemingly uniform expanse of mature 

soils may be too small to separate out as distinct ecological 

sites, but they will function differently from the other parts 

of the site and, therefore, significantly contribute to site 

processes as a whole. Slight changes in topographic position 

may alter ecological functions, but given present ecological 

site classification protocol may be included in a single site. 

(Tongway 1990, Burke and others 1995, Herrick and Whitford 

1995). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Basic processes of concern are those associated with the 

hydrologic cycle, nutrient cycle and energy flow. Also of 

primary concern are successional processes in the functional 

groups of plants and processes associated with functional 

structures for animal habitat (National Research Council 

1994, U.S. Department of Agriculture 1997). 

Identification of the causal factors of degradation to a 

particular land area is complex. Additionally, degradation of 

one area may be caused by treatments in other areas. This 

relationship is particularly evident in riparian systems 

(Briggs 1996), but is also true for most upland systems as 

well. 

The degree to which certain ecological factors function as 

thresholds restricting transition to desire future conditions 

must be assessed (Laycock 1991, Reitkerkand vande Koppel 

1997, Reitkerk and others 1997, Tausch and others 1995, 

Westoby and others 1989). Degree oftree dominance, present 

and potential dominance ofinvasive alien plant species, lack 

of plant species and individuals to respond, shallow soils, 

clayey or sandy textured soils, slopes receiving direct solar 

radiation all seasons of the year, surface soil loss, high 

surface water runoff and intense spring frost action may 

constitute some of the thresholds to be crossed. From the 

threshold assessment both treatment type and treatment 

magnitude can be estimated including management changes 

as well as additions and deletions of organisms and abiotic 

materials. 

As an example, it could be determined that the land area 

under question should function to intercept and accumulate 

resources from the slopes above, but appears to be functioning as a source area, as well as a flow-through area for 

surface water. Secondly, it may be determined that runoff 

and interception dominate the initial hydrologic processes 

and that following precipitation events, transpiration by 

the trees and evaporation from the surface 6 cm of soil in 

interspace areas are the primary hydrologic processes. 

Thirdly, soil analysis may show the presence of eroded soil 

surfaces, deep, medium textured soils, generally well dispersed tree roots with the highest root mass just above and 

in a moderately developed clayey horizon at 35 to 50 cm. 

Landscape Level Analysis 

A complete spatially temporally scaled landscape level 

analysis relative to the land area in question is necessary to 

assure selection of the right treatment area and the right 

treatment and to prevent negative reactions off-site. 

Questions that need to be asked and answered include 

those below. 

• How does the landscape function as a whole? 

• What are the links (connectivity) from the land area 

under consideration to adjacent and removed sites and 

functional units? 

• How does the particular site or land area under consideration fit functionally into the landscape? 

• As to the natural resources of the landscape, which 

areas are source-areas, which areas are flow-throughareas and which areas are run-on areas that intercept 

or accumulate resource materials? 

• What reasons are there to believe that the area under 

consideration should function differently than it is? 

• What are the assumptions made to support the conclusions? 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Consideration of management units and treatment areas 

in isolation is no longer acceptable. It may be the case, for a 

particular area of land, that initial floristics and relay 

floristics are mechanisms determining composition of plant 

species over particular time scales. However, each area is 

linked to other areas in terms of a variety of cri tical resources 

that may strongly influence plant densities, vigor and energy values as well as rates and magnitude of processes. 

In landscape analysis emphasis may need to be placed on 

water flow, paying particular attention to the physical and 

biological factors that control and dominate the water cycle. 

The spatial conceptual framework scales and functional 

units proposed by Wilcox and Breshears (1995) provide an 

excellent comprehensible starting point in landscape analysis, oriented as it is toward water flow in the system. 

Adjustments in scales and functional units may be needed 

in other settings and where woodland management and 

restoration is of concern. Of critical concern is the ecological 

function of each land management area, ecological site and 

functional unit for which restoration treatments are proposed. The degree of movement and accumulation of critical 

resources is hypothesized to be the principle mechanism 

controlling threshold levels of response in arid and semi-arid 

systems (Anderson and Hodgkinson 1997, Burke and others 

1995, Reitkerk and others 1997, Tongway 1990). 

A patchwork land ownership is frequently encountered 

within a landscape making landscape level analysis critical. 

The land area under consideration may need to be managed 

or restored in such a way as to mitigate potentially degrading processes initiated up-slope and to prevent the area from 

being the focal point of processes which degrade down-slope 

areas. 

An example could be a landscape analysis that reveals 

some ofthe water flowing over the surface is from slopes and 

platea us above and most importantly surface water from offsite comes largely during snow-melt. Although the potential 

for accumulation of water and nutrients is considered as 

high, a question should arise as to altering management or 

initiation of restoration practices on the source areas above. 

Management and Restoration 

Actions ___________ _ 

Following the establishment of goals and objective and the 

completion of the structural and functional assessment of 

ecological factors, scaled from the functional unit up to the 

landscape, the problem statement needs to be revisited and 

revised, if necessary. Once this process is complete, sitespecific guidelines of what, when, where and how can be 

addressed. Common actions considered in the management 

and restoration of pinyon-juniper woodlands, such as burning, mechanical removal, seeding and grazing should draw 

their ecological guidelines from a complete set of goals, 

objective and land analysis. If needed guidelines cannot be 

so derived, then some part or perhaps the whole set has 

deficiencies. 

There are an endless number of questions that can be 

raised as to actions taken in ecological management and 

restoration of pinyon-juniper woodlands, however the ecological guidelines for each activity must be found in the 

goals, objectives and ecological land assessment. 

369 
For example, questions as to grazing by domestic livestock 

can be answered only by asking if it will function to meet 

goals and objectives for the land area given the present 

structural and functional condition of the resources of that 

land area. 

More specifically, consideration of fall grazing requires 

that the prescribed grazing meet short term and long-term 

goals, objectives and that appropriate structural and functional resources in time and space are available to do so. 

For instance, using the examples above, fall grazing may 

be acceptable when the focus is on growing season capture 

of water, however, when winter and early spring hydrological events are considered, fall grazing may become 

unacceptable. 

Consideration as to grazing rest time after additions of 

species by seeding should be guided by goals, objectives and 

land analysis. Desired direction, rate of change and area 

function should determine what, when, where and how 

grazing is to be initiated. 

References __________________ __ 

Aldon, E. F., Fletcher, R and Shaw, D. 1995. A checklist for 

ecosystem management in southwestern Pinyon-Juniper. p. 125-

129 In: Shaw, D. W., Aldon, E. F. and LoSapio, C., tech. coords. 

Desired future conditions for pinyon-juniper ecosystems; Symp. 

Proc., 1994, Aug. 12; Flagstaff, AZ. Gen. Tech. Rep. RM-258, Ft. 

Collins, CO: U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Forest and Range Experiment Station. 226 p. 

Anderson, V. J. and Hodgkinson, K. C. 1997. Grass-mediated 

capture of resource flows and the maintenance of banded 

mulga in a semi-arid woodland. Australian Journal of Botany 

45: 331-342. 

Briggs, M. K. 1996. Riparian ecosystem recovery in arid lands. Univ. 

Arizona Press, Tucson. 159 p. 

Burke, I. C., Elliott, E. T. and Cole, C. V. 1995. Influence of macroclimate, landscape position, and management on soil organic 

matter in agroecosystems. Ecological Applications 5: 124-131. 

de Soyza, A. G., Whitford, W. G. and Herrick, J. E. 1997. Sensitivity 

testing of indicators of ecosystem health. Ecosystem Health 3: 

44-53. 

Evans, R A. 1988. Management of pinyon-juniper woodlands. Gen. 

Tec. Rep. INT-249. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station. 34 p. 

Heitchmidt, R K. and Stuth, J. W. editors. 1991. Grazing management. An ecological perspective. Portland, OR: Timber Press 

259 p. 

Herrick, J. E. and Whitford, W. G. 1995. Assessing quality of 

rangeland soils: challenges and opportunities. Journal of Soil 

and Water Conservation. May-June: 237-242. 

Holecheck, J. L., Pieper, R D. and Herbal, C. H. 1998. Range 

management. Principles and practices. (3rd ed) Upper Saddle 

River, NJ: Prentice-Hall, Inc. 542 p. 

370 

Lawton, J. H. 1997. The science and non-science of conservation 

biology. Oikos 79: 3-5. 

Laycock, W. A. 1991. Stable states and thresholds of range condition in North American rangelands: a view point. Journal of 

Range Management 44: 427-433. 

Miller, R F. and Wigand, P. E. 1994. Holocene changes in semiarid 

pinyon-juniper woodlands. BioScience 44: 465-474. 

National Research Council 1994. Rangeland health. New methods 

to classify, inventory and monitor rangelands. National Academy 

Press, Washington, DC. 180 p. 

Plummer A. P. Christensen, D. R and Monsen, S. B. 1968. 

Restoring big-~ame range in Utah. Pub. No. 68-3, Utah Division 

ofFish and Game. 183 p. 

Rietkerk, M. and van de Koppel, J. 1997. Alternate stable states and 

threshold effects in semi-arid grazing systems. Oikos 79: 69-76. 

Rietkerk, M., van den Bosch, F. and van de Koppel, J. 1997. Sitespecific properties and irreversible vegetation change in semiarid grazing systems. Oikos 80: 241-252. . . 

Scarnecchia, D. L. 1995. Viewpoint: The rangeland conditlon concept and range sciences search for identity: a systems viewpoint. Journal of Range Management 48: 181-186. 

Schlesinger, W. H., Reynolds, J. F., Cunningham, G. L., Huenneke, 

L. F., Jarrrel, W. M., Virginia, R A. and Whiford, W. G. 1990. 

Biological feedbacks in global desertification. Science 247: 

1043-1048. 

Tausch, R J. 1996. Past changes, present and future impacts, and 

the assessment of community on ecosystem condition. p. 97-101 

In: Barrow, J. R, McArthur, E. D., Sosebee, R. E. and Tausch, R 

J., comps. 1996. Proceedings: shrubland ecosystem dynamics in 

a changing environment. Gen. Tech. Rep. INT -GTR-338. Ogden, 

UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 275 p. 

Tausch, R J., Wigand, P. E. and Burkhardt, J. W. 1995. Viewpoint: 

plant community thresholds, multiple steady states, and multiple successional pathways: legacy of the Quaternary? Journal of 

Range Management 46: 439-447. . . 

Tongway, D. J. 1990. Soil and landscape processes III the restoratIOn 

ofrangelands. Australian Rangelands Journal 12: 54-57. 

U.S. Department of Agriculture 1997. National range and pasture 

handbook. Draft, Fort Worth, TX. Natural Resources Conservation Service, Grazing Lands Technology Institute. 

Vallentine, J. F. 1989. Range development and improvements. 3rd 

edition. San Diego: Academic Press. 

Werner, P. A. 1990. Principles of restoration ecology relevant to 

degraded rangelands. Australian Rangelands Journal 12: 34.-3~. 

Westoby, M., Walker, B. and Noy-Meir, I. 1989. OpportunIstic 

management for rangelands not at equilibrium. Journal of Range 

Management 42: 266-274. . 

Wiens, J. A., Stenseth, N. C., Van Horne, B. and Ims, R A. 1993. 

Ecological mechanisms and landscape ecology. Oikos 66: 369-380. 

Wilcox, B. P. and Breshears, D. D. 1995. Hydrology and ecology of 

Pinon-Juniper woodlands: Conceptual framework for .field 

studies. p. 109-119 In: Shaw, D. W., Aldon, E. F. and LoSaplO, C. 

(tech. coords.); Desired future conditions for pinyon-juniper ecosystems; Symp. Proc., 1994, Aug. 12; Flagstaff, AZ. G~n. Tech. 

Rep. RM-258. Ft. Collins, CO: U.S. Department of AgrIculture, 

Forest Service, Rocky Mountain Forest and Range Experiment 

Station. 226 p. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Political Guidelines for Management 

and Restoration of Pinyon and Juniper 

Woodlands 

Deanna R. Nelson 

John A. Fairchild 

Carol R. Nunn-Hatfield 

Abstract-In 1989 and 1990, on the he~ls of public protest against 

chaining of pinyon-juniper woodlands on public lands near Moab, 

Utah, the Uinta National Forest and Central Region, Utah Division 

of Wildlife Resources, were proposing to improve big game ranges in 

Spanish Fork Canyon through management of pinyon-juniper. 

Consideration of an array of treatments using various tools (such as 

prescribed fire and clear cutting) resulted in a proposal to create 

numerous small openings 5 to 60 acres in size, and seed these to 

provide additional forage and ground cover. Anchor chaining seemed 

to be the most practical and economical tool with which to accomplish this. Early public involvement quickly revealed strong support, and strong opposition, for pinyon-juniper treatment and specifically for chaining in upper Spanish Fork Canyon. This case-study 

describes the process used and experience gained in developing and 

planning this project. Elements are described which proved critical 

in enabling conflicts to be resolved, implementation to proceed, and 

the project to continue as a multi year effort. 

In 1989, the Uinta National Forest and Central Region, 

Utah Division of Wildlife Resources (DWR), were searching 

for a way to enhance winter range for big game to partially 

compensate for habitat being lost to development along the 

southern portion of the Wasatch Front, adjacent to the 

communities of Provo, Springville, and Mapleton. Attention 

was focused on Spanish Fork Canyon because it contained 

considerable acres of winter and transitional range on public 

lands with potential for improvement. The canyon serves as 

a migrational corridor and it was believed that enhanced 

range there could "short stop" animals by holding them back 

from critical ranges along the Front in the fall and early 

winter. Overall pressure on the lower-elevation ranges could 

be reduced in most years and depredation on private lands 

reduced as well. 

As biologists, hydrologists and ecologists from the two 

agencies looked for opportunities to improve winter range in 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Deanna R. Nelson is Ecologist, USDA Forest Service, Uinta National 

Forest, P.O. Box 1428, Provo, UT 84603. John A. Fairchild is Habitat 

Manager, Utah Division of Wildlife Resources, Central Region, 1115 North 

Main, Springville, UT 84663. Carol R. Nunn-Hatfield is Wildlife Biologist, 

Helena National Forest, Townsend Ranger District, 315 South Front, 

Townsend, MT 59644. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

the canyon, they identified considerable potential for increasing forage production on gentle to moderate slopes on 

soils derived from the Green River Shale. These sites were 

currently occupied by pinyon-juniper woodlands and provided extensive acres of good thermal cover but very little 

forage. Most of these sites were experiencing accelerated 

sheet erosion and gully development, believed to be due to 

large expanses with little ground cover. Openings in the 

woodlands were observed to be occupied by productive sagebrush and mixed mountain brush communities. However, 

these openings were very small, providing insufficient interruption of overland flow and offering little forage to wintering big game. 

Specialists believed that soil productivity and precipitation were adequate to enable substantial increases in forage 

production in openings created in the pinyon-juniper woodland. The sites being considered were felt to be areas onto 

which the woodlands had expanded from adjacent "fire safe" 

sites. Heavy use by domestic sheep in the early part of the 

century had likely contributed to the loss of understory and 

accelerated the increase in tree density by reducing fine 

fuels which carry fire. Biologists looked for a way to create 

openings in the woodland, while maintaining critical thermal cover and travel corridors for big game and other 

wildlife. Ecologists wanted to be able to preserve older 

forests on steeper slopes and ridge tops, as well as healthy 

stands of shrubs scattered throughout the area. A tool was 

needed which could provide the control necessary to create 

a mosaic of openings within a matrix of pinyon-juniper 

woodland. 

\Vhile specialists were conducting field surveys and investigating potential solutions, and preparation was being 

made to begin public interaction, local news broadcasts 

erupted with coverage of controversy over chaining of pinyon-juniper on public lands near Moab, Utah. At this same 

time, local sportsman's groups were pressuring the agencies 

to move forward with some sort of habitat enhancement 

work in Spanish Fork Canyon or allow them to commence 

winter feeding there. Both agencies preferred to pursue a 

long-term solution based on habitat improvement. Agency 

personnel were looking at possible tools to enable them to do 

just that-fire, clearcutting, and chaining. 

Individuals involved in protests at Moab were contacted 

and invited to learn more about work being proposed in 

Spanish Fork Canyon. Public interaction proceeded with 

strong support for treatment, as well as strong opposition. 

Meetings, field trips, and more meetings were held. Analysis 

371 
of alternatives continued. Personnel from both agencies 

agreed that chaining would provide the control needed to 

create the desired mosaic of habitat features. Fire could not 

be adequately controlled under conditions existing in the 

dense woodland to assure that necessary cover would be left. 

Clearcutting could accomplish the desired goals but the cost 

would be much greater. 

Appeals were filed and negotiations undertaken. Both 

proponents and opponents worked hard to find solutions. 

Together with the agencies, they sought compromise that 

would allow the wildlife objectives to be met. It was agreed 

that a test would be performed: work was allowed to proceed 

using chaining as a tool to open no more than 350 acres in 

small patches. The work was to be a trial only, the results to 

be reviewed and evaluated before additional work would 

proceed. At the same time a small thinning would be made 

and the costs and outcome compared-to the chaining. 

Monitoring was established, work completed, and followup monitoring performed. Field reviews with both proponents and opponents were conducted and the outcome was 

favorable enough to opponents that appeals were not pursued further (Brocci 1994). Thinning proved to be less costeffective than chaining (Chadwick and others 1998). Over 

the next five years, a total of more than 1,500 acres of pinyonjuniper habitat was treated in this manner. Forage production on south-facing slopes increased from less than 20 

pounds per acre prior to treatment in 1990, to over 1000 in 

1997. On north-facing sites treated that same year an 

increase from 500 to 1500 pounds per acre was recorded 

(USDA Forest Service 1997). Sediment loss was found to be 

five times greater and soil loss eight times greater on 

untreated (control) plots than on treated (chained and seeded) 

plots (Farmer 1995). Farmer found deer pellet groups to be 

twice as dense on treated plots, and elk five times as dense, 

as on adjacent untreated plots. Resource management objectives to provide additional forage for big game in upper 

Spanish Fork Canyon and to reduce erosion and soil loss on 

these same sites were accomplished. 

Establishing Support and 

Developing Solutions 

Following is an attempt to share what proved to be 

"critical elements" in the planning process for this project: 

things that we believe were important in enabling planning 

to proceed through controversy and disagreement, a oneyear trial to be implemented, and implementation to then 

continue. 

Objectives 

Establishment of clear, honest and obtainable objectives 

proved critical in creating a working relationship with those 

opposed to the project, and provided the basis for developing 

support among potential proponents. In this particular case, 

the project objectives actually provided common ground 

among proponents and opponents. Agreement upon the purpose and need for the project provided a critical commonality 

among all involved, and allowed disagreement to focus on 

issues revolving primarily around methods. 

372 

Much of the area proposed for treatment in Spanish Fork 

Canyon does not lie within a grazing allotment. This eliminated an issue that has proved contentious in similar projects 

and, subsequently, agreement upon objectives came more 

readily. There was little debate over whether additional 

forage would benefit domestic livestock or wildlife. While 

our situation with respect to grazing issues was different 

than many projects involving treatment ofpinyon-juniper, a 

host of other points of controversy and disagreement remained to be resolved, for example: method of treatment, 

visual impacts, consideration of historic and archaeological 

resources, use of natives vs. exotics in reseeding, and the 

potential for objectives to be met on sites selected for treatment. We believe that the steps outlined here could have 

been used to successfully address grazing issues as well. 

Involvement in more recent projects has shown us the 

importance of avoiding laundry lists of objectives. While 

there are many secondary benefits resulting from any welldesigned treatment, it is best to focus on what is actually 

driving the project in question. This allows for greater focus 

on pertinent issues and avoids the impression in some that 

the "deck" is being overwhelmingly "stacked" against any 

opposition. With a long list of objectives it becomes likely 

that objectives will conflict, i.e. providing for one will reduce 

the degree to which another can be accomplished. With even 

a short list of objectives, it may be necessary to prioritize. 

With our project, and just two primary objectives (to reduce 

runoff and erosion from the sites and improve winter and 

transitional-season forage for big game), compromise had to 

be made: it had to be decided whether to treat a maximum 

number of acres to meet watershed objectives, or treat a 

reduced number of acres to allow wildlife requirements to be 

met as well. 

The importance of considering long-term as well as shortterm needs, and to look at the problem and address the 

effects of potential solutions across a large area, became 

readily apparent. Appellants insisted that Utah DWR focus 

on maintaining sustainable populations of big game animals. These discussions ultimately lead to commitments to 

hold elk populations within current carrying capacities and 

to provide temporary reductions in the upper canyon until 

seedings were established. Appellants asked the Forest 

Service to expand the analysis area and extend the number 

of years of treatment considered. While this increased the 

complexity of the analysis and subsequently the amount of 

effort expended, it improved the overall quality ofthe analysis and increased opponents' confidence in it. Additionally, 

the planning work required in subsequent years of implementation was greatly reduced because of the extra effort 

spent in the beginning. 

Public Input 

It proved critical to involve the public throughout the 

planning process, and to continue this effort through implementation and monitoring. Not only is informing the public 

required by law (for Federal agencies and federally-funded 

efforts, under the National Environmental Policy Act), but 

the input provided can be valuable. The public must be 

involved early in the process, to provide an opportunity for 

USDA Forest Service Proceedings RMRS-P-9. 1999 
input before a course is already charted. It may be necessary 

to actively seek out public input, both potentially in support 

of and in opposition to what is proposed. This reduces the 

risk that any unexpected issues will arise later in the 

process. As soon as debate was voiced in the media over 

projects near Moab, District Ranger Tom Tidwell sought out 

those individuals involved and invited their input on our 

project. 

Tidwell worked to create open dialogue among the proponents, the opponents, and the agencies. He provided opportunities for the public to visit potential project sites and 

discuss concerns with the specialists designing the project. 

Through use of mediated debate, lead by a trained facilitator, proponents and opponents were able to talk directly 

rather than through agency personnel. Agreement on the 

fundamental needs driving the project provided common 

ground for the two groups. This made it possible to develop 

solutions by finding a balance in meeting each groups' 

concerns, while maintaining the ability to meet the agreedupon objectives. 

When some concerns could not be sufficiently addressed 

up-front, the agencies and involved public (both opponents 

and proponents) agreed to allow treatment to proceed for one 

phase (350 acres) and postpone any decisions regarding 

further treatment until this work could be evaluated. It was 

also agreed that a small thinning would be created to 

evaluate the costs and test the effects ofthat method relative 

to chaining. Monitoring was designed and implemented to 

address some of the specific concerns of opponents. For 

example, because the literature contained conflicting reports on the effects of chaining and seeding on reducing 

erosion, paired runoff plots were installed to compare effects 

on treated and adjacent untreated sites. Adequate monitoring, evaluating parameters of concern, was fundamental in 

demonstrating the val ue of the project and hence enabling 

work to continue. 

Public input improved the outcome of the project in several ways. As previously mentioned, analysis of a project 

extending across a landscape .and considering several years 

of treatment work, improved the decision making process 

and expedited planning work in subsequent years. Appellants strongly encouraged the Forest Service to use a seed 

mix containing primarily native species and it was agreed 

that a mix with approximately one-halfnative species would 

be used. The mix performed well and was used in subsequent 

years on this project. The Uinta National Forest has since 

increased its use of natives on all seeding projects. The 

establishment of monitoring to document runofffrom treated 

and untreated areas, initiated because of concerns of opponents, has resulted in an entry in the scientific literature 

documenting dramatic results as well as an appropriate 

(and relatively inexpensive) method of evaluating effects at 

a scale appropriate for such projects. 

Evaluate Options 

Consideration of a full range of options, looking at all 

reasonable tools, was necessary to assure good decisionmaking and important in developing credibility and support 

for the final decision. It was important to fully assess the "no 

action" alternative. Analysis of the no-action should affirm 

the validity of the purpose and need for action. Alternatives 

USDA Forest Service Proceedings RMRS-P-9. 1999 

should be developed which address concerns, but it is critical 

to then evaluate how well the alternative can address the 

objectives. When all parties agreed to the objectives, it 

became simple to reject alternatives that quelled specific 

concerns but did not enable accomplishment of objectives. 

All reasonable alternatives should be fully assessed and 

given the same level of consideration. Experience has shown 

that more detailed analysis of some alternatives over others 

more likely results in suspicion than in strengthened support for that alternative. Each should be analyzed across a 

landscape and projected through a reasonable period oftime 

to avoid the perception of a segmented, or piece-meal, analysis which does not fully reveal the cumulative effects of 

multiple years of work. This provided an appeal point in our 

case. 

Careful Implementation 

Care in implementation of the project, and in particular 

the close attention paid to detail in the design and layout of 

treatment units, built substantial support for the project. 

Criteria for unit design and layout were developed by experienced personnel from both agencies, assuring that project 

objectives would be met. Utah DWR biologists worked carefully to assure that adequate thermal cover would remain 

and that travel corridors would be provided. Forest Service 

hydrologists and ecologists worked together to determine 

which sites had the greatest capabilities for meeting erosion 

reduction and forage production objectives. Archeological 

surveys were conducted and protection provided for "eligible" sites. Implementation was closely supervised to assure that the desired outcome was achieved. Personnel (at 

least one biologist and several technicians) were on the sites 

with chaining and seeding contractors at all times. 

Interagency Cooperation 

Cooperation among interested agencies was very important to the success ofthe project. Both the Forest Service and 

Utah DWR provided funding and participated actively in all 

phases from planning to monitoring. Joint efforts in planning and design proved especially important in creating 

agreement and developing a sense of ownership in the 

project with agency personnel. The two parties worked 

together to develop support from the public, participated 

together in discussions with opponents, jointly pursued 

solutions and evaluated results. We feel this contributed 

considerably to the credibility of the project. 

Nonagency Partnerships 

Endorsement of the project by non-governmental organizations, especially groups willing to contribute funding or inkind assistance, helped to build a broad base of support for 

the project. Partners' willingness to make a tangible contribution to the project by providing cash support and/or 

volunteering time and talents proved successful in drawing 

favorable attention to the project, and served as a vote of 

confidence. Funding provided by partners was critical in 

some years to enabling work to proceed. With continually 

shrinking budgets, being experienced by both state and 

373 
federal agencies in recent years, such funding becomes 

increasingly important. 

Partnerships create a responsibility for agency personnel 

to keep non-agency players informed. Circumstances often 

prevent these groups from participating in the day-to-day 

development and implementation ofthe project. This makes 

it important for the agencies to keep these groups informed 

as to the status of the project, by providing regular updates 

even in periods of little activity. 

Dedication of Proponents and Opponents 

It is important that all parties involved, both those who 

fully support the project and those who don't, are dedicated 

to spending the time necessary to fully explore issues and to 

remaining open to each other's ideas. This requires agency 

specialists and decision-makers to spend time with all groups 

involved, to listen to their concerns and ideas and explore 

these fully. Field reviews provided an excellent opportunity 

to accomplish this. This proved to be the best way to help the 

public develop an understanding of the project, while creating a forum for airing and discussing concerns and exploring 

ways to mitigate those issues. At a critical point when 

solutions were needed so that decisions could be made 

mediated debate (discussed above) served a critical role i~ developing compromise and agreement. 

Agency Decisionmaker Support 

Excellent support and dedication by the deciding officer, 

in this case the district ranger, was without question one of 

the most critical components enabling compromise and 

collaboration to develop from disagreement. The district 

ranger first became intimately familiar with the project, it's 

purpose and need, its objectives and the proposed action. He 

then gave priority to spending time with the proponents and 

opponents, helping them to understand the agencies' proposal and then listening to and coming to understand their 

feelings about the proposal. He worked to build support for 

the objectives of the project, while remaining open to ideas 

and concerns. He was dedicated to finding solutions that 

enabled our objectives to be met, and skillful in dealing with 

controversy. 

Our district ranger's insistence on remaining flexible and 

seeking solutions prevented an unsurmountable stalemate 

from developing. His willingness to accept opponents' request to implement a one-year trial, and their faith that he 

would stand behind that agreement, was an important 

turning point for the project. He worked with agency specialists to see that adequate monitoring was established so that 

the work could be properly and fairly evaluated. He maintained contact with the opponents throughout planning, 

implementation and assessment to assure that they understood how work was progressing. 

Conclusions ------------------------------ Experience obtained through the development, implementation and monitoring of the Spanish Fork Canyon big 

game winter range enhancement project revealed a handful 

374 

of factors that proved important in dealing with the controversy surrounding treatment of pinyon-juniper woodlands: 

• develop clear, honest and obtainable objectives 

• solicit and use public input, representing diverse points 

of view 

• consider an array of options and alternatives 

• establish interagency and partner support 

• encourage proponents and opponents to dedicate the 

time needed to pursue solutions and create an open 

environment for exchange of ideas 

• decisionmakers must dedicate the time and energy 

necessary to establish relationships with proponents 

and opponents, find common ground, and develop 

solutions 

• use great care in planning (including design and layout), implementation and monitoring 

While most or all of these items may be considered to reflect 

primarily common sense, we often see insufficient time and 

energy dedicated to them "up-front." Instead, an equal or 

greater investment is required to struggle through stalemates which develop when public involvement comes too 

late. Of course, such situations cannot always be avoided but 

prevention is a worthwhile goal. 

We recognize that in the experience shared here, all 

conflicts were not resolved. Some opponents remained unhappy with the decisions made but chose not to commit the 

time necessary to pursue solutions. We are grateful to those 

who remained dedicated to the process of finding answers. 

Their contributions of energy and ideas enhanced the outcome of the project. 

Acknowledgments 

The authors wish to thank the many individuals and 

organizations who's efforts shaped this project, greatly improving the outcome. Special thanks to Rocky Mountain Elk 

Foundation, Utah Sportsman Alliance, and the appellants, 

who contributed funding, materials, and/or labor to the 

project and gave substantially of their time and talents. 

Heartfelt thanks to our colleagues in our own organizations, 

as well as those with Great Basin Cooperative Experiment 

Station, Forest Service Rocky Mountain Research Station, 

and Brigham Young University Department of Botany and 

Range Science. 

References -------------------------------- Brocci, Jan. 1994. Rough times on the Wasatch Front-rejuvenating a winter range. Bugle. Spring: 44-54. 

Chadwick, J. Holbrook. Thinning versus chaining: which costs 

more? In: Monsen, Stephen B.; Stevens, Richard; Tausch, Robin 

J.; Miller, Rick; Goodrich, Shere!' (This proceedings). Proceedings: ecology and management of pinyon-juniper communities 

within the interior west. 1997 Sept. 15-18, Provo, UT. Ogden, UT: 

U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Research Station. 

Farmer, Mark E. 1995. The effect of anchor chaining pinyon-juniper 

woodland on watershed values and big game animals in central 

Utah. Unpublished thesis. Brigham Young University, Provo, 

UT. 46 p. 

USDA Forest Service. 1997. Unpublished data summary. Uinta 

National Forest, Provo, UT. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Old-Growth Juniper and Pinyon Woodlands 

Rick Miller 

Robin Tausch 

Wendy Waichler 

Ahstract-The forestry, rangeland, and ecology communities have 

generally overlooked semi-arid old-growth woodlands. These ancient woodlands have some of the oldest trees in the Intermountain 

region, exceeding ages of 1,000 years. Old-growth are typically 

structurally more complex than postsettlement woodlands adding 

biological diversity to the landscape and providing an important 

source of habitat for many organisms. Mapping and inventorying 

old-growth woodlands are extremely important in developing management and land-use plans. Information is also needed on structure, function, gap dynamics, tree mortality, and succession following disturbance. 

Old-growth juniper and pinyon woodlands in the West 

generally do not fit the typical image most people have of 

old-growth coniferous forests. In a recent symposium in the 

southwest, Swetnam and Brown (1992) stated; "Many peoples 

image of old-growth are the stately monarch trees with 

shafts of sunlight streaming down through tall, dense canopies. However, in the southwest, many of the old-growth 

stands do not fit this stereotype." Some of the oldest stands 

throughout the Intermountain West are low statured open 

semiarid woodlands composed of such species as bristlecone pine (Pinus longaeva), limber pine (P. (lexilis), juniper 

(Juniperus sp.) and pinyon (Pinus sp.). Old woodlands usually differ in structure and function from postsettlement 

woodlands thus adding diversity at the community and 

landscape levels. Although considerable research has been 

conducted in old-growth for other conifer species, work 

addressing old-growth in juniper and pinyon woodlands is 

very limited. In addition, the concern over the rapid expansion of juniper and pinyon woodlands during this century 

has overshadowed the presence and values of these 

presettlement woodlands. Ancient woodlands are frequently 

overlooked in management plans and inventories where 

they are often lumped with postsettlement stands. Wildlife 

studies conducted in juniper or pinyon-juniper woodlands 

have also generally not separated post from presettlement 

stands. 

In: ,Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Rick Miller, Professor of Range Ecology, EOARC, Oregon State University 

HC 71, 4.51 Hwy 205, Burns OR 97720. Robin Tausch, Project Leader, USDA 

Forest Service, Rocky Mountain Research Station, Reno NV. Wendy 

Waichler, Graduate Research Assistant, Department of Rangeland Resources, Oregon State University, Corvallis, OR 97731. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

The intent of the paper is to describe old-growth as it 

relates to semiarid juniper and pinyon woodlands in the 

Intermountain West and briefly summarize their characteristics, variability, and some of the current work going on 

in these old stands. Specifically we will: 

1. Describe old-growth and contrast juniper and pinyon 

stands with other coniferous stands. 

2. Describe the values of old-growth juniper and pinyon 

woodlands. 

3. Describe the different types of old-growth woodlands for 

western (Juniperus occidentalis spp. occidentalis), Utah 

juniper (J. osteosperma) and pinyon (Pinus spp). 

4. Discuss management considerations for old-growth 

woodlands. 

Old-Growth: A Generic 

Description 

Old-growth work in the northwest United States has been 

focused on the more mesic heavily forested areas. In the 

Great Basin old-growth work is almost non-existent. The 

forestry, rangeland, and ecology communities have generally overlooked semi-arid old-growth woodlands. What is 

known about old-growth juniper and pinyon comes largely 

from anecdotal mentions in the literature, noting the occurrence of presettlement trees on rimrock, low sagebrush 

tablelands, and other fire resistant areas. Several attempts 

have been made to describe pinyon-juniper old-growth 

(Popp and others 1992, Mehl 1992) but little actual work 

has been conducted in these stands. 

Old-growth forests are unique from younger forests in 

both structure and function (Mehl 1992, Kaufmann and 

others 1992). The U.S. Forest Service defines old-growth 

forests generically as ecosystems distinguished by old trees 

and related structural attributes. Their definition states 

that old-growth encompasses the later stages of stand development that typically differ from earlier stages in a variety 

of characteristics which may include tree size, accumulations of large dead woody material, number of canopy 

layers, species composition, and ecosystem function (USDA 

Forest Service 1993). Structural features important in characterizing old -growth in the Intermountain West vary widely 

across forest type, climate, site conditions, and disturbance 

regimes (Kaufmann and others 1992). 

Functionally, ecological interrelationships in old-growth 

forests are more complex than younger forests (Moir 1992). 

Old-growth ecosystems are characterized by having a componellC of old trees that have a biochemistry of secondary 

metabolic products, some of which may provide high resistance to insects and disease. Relative to younger trees, the 

oldest trees have approached their maximum size and have 

375 
nearly ceased height growth, and the tree crowns may be 

in various stages of decline. On average, mortality and 

respiration offset the rate of production of new biomass, and 

net productivity of the ecosystem approaches zero (Kaufmann 

1992). 

Old-growth detrital food webs are usually more complex 

than found in earlier stages of stand development. Decay 

processes, some of which may involve nitrogen fixation, 

occur in snags, down logs, and dead portions ofliving trees. 

Arthropods and other microzoans occur in the forest litter 

and within decaying stems of old living trees, whose decay 

may involve nitrogen fixation. There may be mixed communities of cryptograms and associated invertebrates on tree 

branches and stems. The food web further includes fungalsmall mammal relationships (Moir 1992). 

Structural and functional complexity of old-growth ecosystems increases their biological value. Important values of 

these old stands include habitat for a variety of plant and 

animal species, climate reconstruction, pools of genetic resources (Kaufmann and others 1992), and wood for dating 

archeological sites. In addition, esthetic and spiritual values 

are frequently mentioned in relation to old-growth stands. 

Old-Growth Juniper and Pinyon 

Woodlands -------------------------------- Old-growth characteristics listed above may not directly 

apply to semi-arid woodlands in the Intermountain West. 

However, like other conifer communities, old-growth semiarid woodlands should be defined on the basis of tree age, 

and stand structure and function. Nonetheless little to no 

information is available on stand structure, rates of mortality and decomposition, gap dynamics, thinning, food webs, 

and nitrogen fixation for old-growth juniper and pinyon 

woodlands. Information relating old-growth woodlands to 

wildlife values is also limited since very few wildlife studies 

have described stand structure or separated old-growth 

from postsettlement woodlands. 

Single Tree Perspective 

A frequently asked question is; "What is an old-growth 

juniper or pine?" One age separation may be made on the 

basis of tree establishment occurring prior to and following 

Eurasian settlement. In the central and northern portions of 

the Great Basin, the rapid expansion of western, Utah 

juniper, and pinyon coincided with Eurasian settlement in 

the late 1860s and 1870s (Burkhardt and Tisdale 1976, 

Tausch and others 1981, Young and Evans 1981, Tausch 

and West 1988, Miller and Rose 1995). Woodland expansion 

for much of this region began in the 1870s. Based on the 

chronology of past events throughout the northern Great 

Basin we would define postsettlement trees as having 

established sometime after 1870 and presettlement trees 

establishing prior to 1870. However, old-growth can also be 

based on morphological characteristics of the tree, which 

develop slowly over time. As juniper and pinyon age, canopy 

morphology shifts from cone shaped to a rounded top. As 

age advances the tree may also develop a combination of 

the following characteristics; broad non symmetric tops, 

deeply furrowed bark (primarily juniper), twisted trunks or 

376 

branches, dead branches and spike tops, large lower limbs, 

trunks containing narrow strips of cambium (strip-bark) 

(mostly in juniper), hollow trunks (rare in pinyon), large 

trunk diameters relative to tree height (in western juniper), 

and branches covered with a bright yellow green lichen 

(Letharia sp.) in bothjuniper and pinyon. Tree size, particularly height, is dependent upon site characteristics. 

Tree age within the old-growth stand is an important 

index in assessing the stage of old-growth development 

(Swetnam and Brown 1992). Assessing stand age also 

determines the rarity or uniqueness of the woodland. Western juniper can easily attain ages exceeding 1,000 years 

(Miller unpublished data). The oldest living western juniper 

(Juniperus occidentalis ssp. occidentalis) currently reported 

isjust over 1,600 years old. However, many old trees cannot 

be aged due to rotten trunk centers. Utah juniper can also 

exceed 1,000 years in age and pinyon can exceed 600 years 

(Tausch and others 1981). 

A Woodland Perspective 

At the community level, old-growth juniper woodlands 

should be described on the basis of the presence of old trees 

and structural characteristics such as standing and down 

dead, decadent living trees, cavities, and branches covered 

with lichens. The U.S. Forest Service definition based on 

such community structure characteristics has been applied 

to pinyon-juniper by the Rocky Mountain Region (Mehl 

1992) and the Southwestern Region (Popp and others 1992) 

of the Forest Service. The resulting minimum structural 

attributes for this procedure are shown in table 1. In a 

narrative description, Popp and others (1992) stated, pinyon-juniper stands may consist of all ages or one age. 

Dominant trees are often 400 years old. Trees 800 to 1000 

years old have been recorded. The trees can be single 

stemmed or have a sprawling multi-stemmed character. A 

few stands may have closed canopies with single or both tree 

species, with little or no understory, but most stands are 

open-grown with widely scattered trees of one or both species with a wide variety of understory vegetation. The 

pinyon-juniper type is climax, woodlands shifting to grasslands or shrub steppe only following disturbance, such as 

fire (MehI1992). In the absence of disturbance these communities will eventually return to pinyon-juniper woodland. 

The above characteristics describing old-growth pinyon 

andjuni per woodlands in the southwest and southern Rocky 

Mountains provide a good first attempt but are too generic 

and limited to appropriately fit all old-growth woodlands in 

the Intermountain West. Franklin and Spies (1986) state; a 

single set of attributes and quantities cannot classify all 

stands as either old or young. Old-growthjuniper and pinyon 

woodlands occur across a wide range of parent materials, 

soils, aspect, slope, elevation, climate, and disturbance regimes (Kaufmann and others 1992). To account for some of 

this variation old-growth juniper and pinyon woodlands 

maybe characterized into old-growth, woodland types. Woodland types would be separated out by such factors as ecological province, major landscape features including geology, 

parent materials, and landform. In addition to these physical parameters structural characteristics would also be used 

to classify old-growth woodland types. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 1-Minimum structural attributes used by the U.S. Forest Service in 

both the southern Rocky Mountain and southwestern regions to 

identify old-growth pinyon-juniper stands (derived from Mehl 1992 

and Popp and others 1992). 

Live Trees 

Tree per acre 30 

Diameter at root collar 

Age 

12 inches, with variation in diameter 

200 years 

Decadence present 

bole or root rot 

Yes, dead, broken, or deformed tops and/or 

Number of tree canopies 

Other 

Single story 

Upper canopy trees are slow growing 

Variation in tree diameter 

Basal area of 23 square ftlacre 

Dead Trees 

Standing 

NumbeLper acre 

Diameter at root collar 10 inches 

Down 

Pieces 

Diameter 

2 per acre (10ft long segments) 

10 inches 

Canopy closure 

Total canopy cover 35 percent 

Ecological provinces can provide a first separation in the 

classification of old-growth woodlands accounting for some 

of the heterogeneity across the Intermountain West. From 

eastern Oregon to southeast Nevada and into Utah rainfall 

distribution varies from almost all of it arriving in the winter 

to where up to a third or more of the annual precipitation 

comes in the summer. From north to south the environmental gradient varies from the cold deserts surrounded by 

coniferous forests in Oregon and Idaho to mountain slopes in 

the south that are surrounded by the Mojave Desert. The 

combination of these envirqnmental gradients with the 

basin and range topography of the Great Basin, creates 

considerable environmental variation (West and others 1978). 

This environmental variation has been divided into ecological provinces (fig. 1) based on the floristic regions of Cronquist 

and others (1972), the Ecoregions described by Bailey and 

others (1980 and 1994), and soil-plant relationships in 

Oregon described by Anderson (1956). Ecological provinces 

differ somewhat in climate, topography, geology and soils, 

however, similarities and dissimilarities of vegetation between provinces are not always clear. Depending on management objectives further separation of old-growth woodlands is necessary. 

We are currently working on a classification system for 

old-growth woodlands. In the proposed classification we 

consider; (1) community type, based on ecological province, 

landform, dominant shrub, dominant grass, soils, and topography (derived from West and others 1997), (2) tree age 

composition and structure, and (3) composition of the understory (fig. 2). The approach allows the composition of the 

understory and overstory to be evaluated separately but 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Figure 1-Ecological Provinces in the Intermountain West (derived from Anderson 1956, Cronquist 

1972, and Bailey and others 1980, 1994). 

377 
Tree Age Class Composition 

- Presettlement- +--Postsettlement--

Senescent ... Late Mature- Mature ...... Young Mature""" Sapling +-+ Early 

Native 

Perennial Low 

Undisturbed understory 

Early Old Growth 

Woodland Successional Type II 

Woodland 

Disturbed Understory 

IntroducedL---------------------' 

Low ..... ------Type I ------. High 

Disturbance 

Figure 2-A conceptual model illustrating the range 

of possible conditions occurring within a juniper 

woodland type (modeled after Woodgate and others 

1996). The horizontal axis represents composition 

of tree age classes. The vertical axis represents 

composition of understory species. Type I disturbances primarily affect the overstory age structure 

such as fire, cutting, land clearing, chaining. Type II 

disturbances influence understory composition and 

structure, such as grazing, off road vehicles, and 

land clearing. 

High 

combined for the classification. In central Oregon, oldgrowth woodlands are commonly found where the overs tory 

canopy has changed little since settlement but the understory composition has been largely altered. The age of a 

stand, plotted along the horizontal axis, is based upon the 

proportion of tree age classes. Age classes currently proposed are presettlement; (1) standing dead, (2) senescent 

(>50 percent dead), (3) senescing 5-50 percent dead, (4) late 

mature (300+ yrs), mature (12'0-300 yrs); postsettlement, 

(5) young mature, (6) sapling (3-10 ft tall), and (7) juvenile 

«3 ft tall). Abundance of down dead trees is also considered. 

(We are still working on age class definitions for western 

juniper). For mapping purposes, Woodgate and others (1996) 

suggested old-growth semi-arid stands in Australia consist 

of a minimum of 10 percent senescent trees and a maximum 

of 10 percent regrowth or young trees. For juniper woodlands that attain ages exceeding 1,000 years old it may be 

helpful to separate stands into several old-growth age 

classes. In westernjuniper, stands that are 150 to 300 years 

old may be structurally different than stands exceeding ages 

of 500 years. 

Western Juniper (Juniperus 

occidentalis subsp. occidentalis) 

This subspecies of westernj uni per is considered the northwestern representative of the pinyon-juniper woodland 

(Franklin and Dyrness 1973). The prehistoric record indicates the distribution and dominance ofwesternjuniper has 

greatly fluctuated during the past 5,000 years (Miller and 

378 

Wigand 1994). Western juniper generally increased during 

periods of mild wet climate, declining with fire at the end of 

these wet periods. The pollen record indicates western 

juniper declined during the past 500 years prior to settlement. Old-growth stands in existence today are relicts ofthe 

extensive stands that characterized the landscape over the 

past 4,000 to 5,000 years. In contrast, stands that have 

established after the 1870s appear to be considerably more 

dense and to have developed under different environmental 

conditions than the pre settlement stands which preceded 

them during the past 5,000 years. 

In Oregon, estimates ofless than 3 percent of the current 

5 million acres of western juniper woodlands are characterized by trees >100 years old (USDI-BLM 1990). Although 

not well documented similar proportions of western juniper 

old-growth are probably found in northeastern California, 

northwestern Nevada, and southwestern Idaho. However, 

the proportion of pre- and post settlement trees varies across 

ecological provinces. Acreage of old-growth is not know since 

mapping and inventory of old -growth westernj uni per woodlands is limited throughout its range. In the southwest, the 

occurrence of old-growth woodlands is rare (Swetnam and 

Brown 1992). 

Old-growth western juniper stands grow on soils derived 

from three major parent materials, located in six ecological 

provinces, the John Day, Mazama, High Desert, Snake 

River, Klamath, and Humboldt (fig. 1) Old-growth stand 

structure is typically uniquely different between the different provinces and parent materials. The igneous zone 

dominates most of the landscape in the High Desert and 

Klamath ecological provinces, and the Owyhee Plateau in 

the Humboldt province. Igneous rock is also the most abundant parent material in the southwestern portion of the 

Snake River province, where western juniper occurs. In 

these provinces old-growth juniper typically grows widely 

spaced on shallow, rocky, heavy clay soils, or rimrock supporting limited fine fuels to carry a fire. Juniper Mountain, 

in Harney and Lake Counties, is a unique example of dense 

old-growth woodlands growing on deep well-drained soils, 

which typically supports mountain big sagebrush steppe 

community types. Sedimentary soils, primarily found in the 

John Day province, support widely spaced old trees with 

little understory to carry fire. The aeolian sands in the 

Mazama and eastern edge of the High Desert provinces 

support the most extensive stands of old-growth western 

juniper woodlands. 

Igneous Zone of the High Desert, Klamath, 

Humboldt, and Snake River Ecological 

Provinces 

Presettlement juniper trees are typically found on rocky 

surfaces or ridges (fig. 3), and low sagebrush (Artemisia 

arbuscula) tablelands in the High Desert, Klamath, 

Humboldt, and Snake River Ecological Provinces (Vasek 

and Thorne 1977, West 1984, Miller and Rose 1995). The low 

sagebrush tablelands occupied by presettlement juniper 

trees (fig. 4) probably account for the greatest proportion of 

old-growth juniper across these provinces. Old-growth 

juniper probably accounts for less than 3 percent of the 

woodlands across these provinces. The dominant grass is 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Figure 3-Ancient western juniper growing out of 

rock crevices covered by a few inches of soil. 

typically Poa sandbergii, with Festuca idahoensis growing 

beneath the juniper tree canopies. These juniper low sagebrush tablelands often occupy extensive flats with less than 

5 percent slope, although slopes can approach 30 percent. 

The rocky, shallow heavy clay soils are primarily of igneous 

(basalt, andesite, ryolite) origin. Although soils are shallow 

juniper roots often penetrate the fractured bedrock. 

Tree canopy cover on the low sagebrush tablelands is 

highly variable and may approach 20 percent, but typically 

ranges below 5 percent. On the Devils Garden in northern 

California, 63 percent of trees aged ranged between 200 

and 500 years old. The remaining 37 percent were older than 

500 years (Miller unpublished data). However, many trees 

could not be aged due to rot. Tree densities in a majority of 

these low sagebrush tableland communities have increased 

during the past 100 years (Young and Evans 1981, Miller 

and Rose 1995, Miller and Rose submitted). Low presettlement tree densities in these communities can probably 

be attributed to limited tree establishment due to heavy clay 

soils, slow growth rates, and occasional fires. Lower CO2 

concentrations may have also attributed to slower rates of 

tree establishment prior to 'the 1900s (Farquhar, 1997). 

Occasional fires did burn across these low sagebrush 

Figure 4-Juniper low sagebrush Sandberg bluegrass 

tablelands. Tree canopy is usually sparse and trees are 

widely scattered. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Sandberg bluegrass community types (Young and Evans 

1981, Miller and Rose submitted). In south central Oregon, 

two extensive presettlement fires burned across this type 

between 1700 and 1880 (Miller and Rose submitted). Mean 

fire intervals of 80 to 100 years were probably adequate to 

create a stand of widely scattered juniper trees. However, 

single tree lightening fires were probably more common 

occurrences across the juniper low sagebrush tablelands. 

On the deeper igneous soils fire limited the development 

of old -growth westernj uni per woodlands (Miller and Wigand 

1994). These soils typically support mountain big sagebrush 

steppe communities. Mean fire intervals between 12 and 25 

years occurred in these shrub steppe communities (Houston 

1973, Burkardt and Tisdale 1976, Martin and Johnson 1979, 

Miller and Rose submitted). However, Juniper Mountain 

located east of Alkali Lake in central Oregon is an exception 

(fig. 5) This site may serve as a model as to what most of the 

mountain big sagebrush type would have looked liked iffire 

had played a minor role in the sagebrush ecosystem. Preliminary work indicates the age of overstory trees range 

between 350 and 600 years. Understory trees 3 to 5 ft tall 

were between 100 and 200 years old. This is the only oldgrowth stand we have measured throughout the range of 

westernjuniper that meets the criteria of canopy cover (~30 

percent) defined by the U.S. Forest Service. On the north 

and northeast aspects tree canopy cover ranged between 35 

and 50 percent. On south and southwest aspects tree cover 

ranged between 20 and 35 percent. Shrub cover accounted 

for less than 1 percent of the understory cover. Dominant 

herbaceous species were Idaho fescue (Festuca idahoensis) 

on the north aspects and Thurber needlegrass (Stipa 

thurberiana) on the south aspects. 

Sedimentary soils in the John Day 

Ecological Province 

Very little work has been conducted on old-growthjuniper 

on these soils. The majority of these soils occupied by oldgrowth western juniper occur in the John Day province 

with limited amounts occurring in the High Desert and 

Figure 5-Dense ancient western juniper woodland growing on the north aspect of Juniper Mountain, in eastern 

Oregon. Soils are deep loamy Argixerolls and Haploxerolls. 

Tree canopy cover varies from 40 to 60 percent. 

379 
Figure 6-Ancient western juniper tree growing on 

sedimentary soils in central Oregon. 

Klamath provinces (fig. 1). These soils usually support a 

very low density of trees and sparse understory incapable of 

carrying fire (fig. 6). The accumulation of both down and 

standing dead and decadent trees on many of these sites 

indicates the presence of very old stands. Tree ages on these 

soils exceed 1,000 years. Dead trees may remain standing 

for hundreds of years. These old-growth stands probably 

account for less than 3 percent of the juniper woodland 

component. 

Aeolian Sands in the Mazama and Western 

High Desert Ecological Provinces 

The aeolian sand region is located in the Mazama and 

northwestern portion of the High Desert Ecological Provinces,just east of the Cascade Mountain range (fig. 1) This 

region supports the most extensive stands of old-growth 

western juniper woodlands (fig. 7). These old woodlands 

probably account for over 10 percent of the juniper woodlands in the Mazama Province. Soils in the Mazama Province are strongly influenced by Mazama pumice. In the 

northwest corner of the High Desert Province, sources of 

Figure 7-Qld woodland growing on aeolian sands. 

Tree canopy cover is 15 percent and dominant understory grass is Idaho fescue or western needlegrass. 

380 

wind blown sands are primarily from Pleistocene lake beds, 

and Mount Mazama and Newberry Craters pumice. Stand 

structure varies across these provinces but are generally 

open with tree canopy cover typically ranging between 10 

and 15 percent. Live tree density ranged between 15 and 25 

per acre, standing dead 56 per acre, and down dead 1 to 7 per 

acre. Very slow decomposition rates allow for an accumulation of dead wood on these sites. Burned stumps and standing weathered trees can persist for hundreds of years. Tree 

ages are variable ranging between 200 and> 1,000 years. 

Currently we have aged several trees ranging between 1,200 

and 1,600 years old. Fires are typically small, burning single 

to several trees within a stand. However, old fire scars on 

these landscapes indicate occasional extensive fires burning 

in these stands. Idaho fescue, western needlegrass (Stipa 

occidentalis), and bluebunch wheatgrass (Agropyron 

spicatum) (primarily on the west and southwest aspects) 

frequently dominate the understory. However, in the Bend 

and Redmond area which lies below 5,000 ft, rabbitbrush 

(Chrysothamnus sp.) and cheatgrass (Bromus tectorum) will 

dominate the understory on sites that have been overgrazed or mechanically disturbed. 

Wildlife Values _______ _ 

It is important that future wildlife work describes both 

woodland structure and stand age. Old-growth woodlands 

are typically more structurally complex than postsettlement 

woodlands. More than 80 species of animals use living trees 

with decay, hollow trees, snags and logs in the interior 

Columbia River Basin (Bull and others 1997). Although this 

report excluded juniper species, our breeding bird surveys 

show old-growth western juniper woodlands provide important habitat for many bird species. Preliminary results from 

our songbird surveys indicate an increase in cavity nesters 

in old-growth compared to postsettlement woodlands. Densities of cavity nesting mountain blue birds, red- and whitebreasted nuthatches have been consistently greater in old 

stands. Some of our highest mountain blue bird counts also 

occur in shrub steppe communities adjacent to old-growth 

stands. Our lowest counts have been recorded in closed 

postsettlement stands. At this time we have no information 

on cavity densities or minimum tree ages where cavities are 

typically found. However, the greatest number of cavities 

typically occurs on trees greater than 400 years. Wood rats 

also commonly nest in the hollow trunks of western juniper. 

In addition to wood rats, the abundance and diversity of 

small mammals is typically greater than in postsettlement 

woodlands (Willis and Miller, this symposium). 

During the winter a large abundance of frugivores, including western and mountain bluebirds, cedar waxwings, 

American robins, and townsend solitares have been reported in the extensive juniper stands in central Oregon in 

the Mazama Province (Contreas 1997). These stands are 

predominately open old-growth woodlands, with 15 percent 

or less canopy cover supporting good crops of juniper berries. 

Dense woodlands produce very few berries (Miller and Rose 

1995). We have observed heavy berry crops on trees over 500 

years old growing in relatively open stands. Tree density 

appears to have a greater effect on the potential berry 

production than tree age. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Western Juniper (J. occidentalis 

subsp. australis) 

This subspecies of western juniper, found in the Sierra 

Nevada Mountains south ofabout 40 degrees north Latitude 

(High Sierra Ecological Province, fig. 1), is seldom present in 

woodlands. This subspecies, usually found on rocky and 

shallow soil areas, is typically associated with various montane conifer communities. Oldjunipers tend to be common in 

these open, mixed conifer forests. There are at least two 

relatively large areas where the sierra juniper is associated 

with singleleaf pinyon in woodland communities. One of 

these sites is in the lower drainage of the east and west 

forks of the Carson River east and south of Markleeville, 

California. These woodland areas are almost exclusively on 

rocky and shallow soil sites that h~ve apparently greatly 

reduced fire frequency. Large areas of these woodlands, and 

possibly the majority, are old-growth communities dominated by large, old pinyon and juniper. The prehistoric 

record for these woodlands is unknown but because of their 

locations they may to be of relatively recent (late Holocene) 

origin. 

Extensive singleleaf pinyon, western juniper (southern 

subspecies) woodlands also occur near the southern end of 

the Sierra Nevada Mountains. These are on large areas of 

rolling topography along the south fork of the Kern River, 

mostly the east side, from about Chimney Peak north to near 

Kennedy Meadows. Scattered occurrences of these woodlands may also be present along the east slopes of the Sierra 

Nevada Mountains above Owens Valley. Unlike stands 

further north, these are typical post-settlement woodlands 

dominated by younger trees, and their appearance resembles 

woodlands found throughout much of western Nevada. The 

proportion of old-growth in this location is unknown, but 

appears to be very limited. The prehistoric record of these 

woodlands is also unknown but appears to be largely of 

post-European settlement age. 

Pinyon-Utah Juniper _____ _ 

Woodlands of the Great Basin of Nevada, western Utah, 

and eastern California cover a large land area (about 8 million 

hectares, 18 million acres) of considerable environmental 

complexity (Tueller and others 1979). The distribution, 

dominance, and species composition of these woodlands has 

seen even greater fluctuation over the last 5,000 years 

than the northern subspecies of western juniper. Pinyon, for 

example, was absent from most of Nevada and Utah during 

the Pleistocene and migrated into the area during the 

Holocene (Nowak and others 1994a,b). For some areas in 

western and northern Nevada, pinyon has been present for 

less than 2,000 years. The structure of the woodlands, and 

the overs tory-understory competitive patterns are often 

different when pinyon is present than when it is absent. 

Throughout the last 5,000 years woodland dominance has 

widely fluctuated and, following reduction during an extended drought, was slowly expanding over about a 400 year 

period prior to the mid nineteenth century (Wigand and 

others 1995). The rapid expansion that has occurred during 

the last century to century and a half (Tausch and others 

USDA Forest Service Proceedings RMRS-P-9. 1999 

1981 Tausch and West 1988) may be the largest of the 

Holo~ene. This expansion is continuing. 

The environmental and topographic heterogeneity of pro vinces in the Great Basin of Nevada and Utah is generally 

greater than the provinces further north and east (fig. 1) 

Even though the ecological provinces of Nevada and Utah 

share many similar environmental conditions, there is a 

higher level of heterogeneity within as well as between, 

provinces (West and others 1979, West and others, in press). 

Soils are also highly variable, again both within and between provinces. Overall, the quantity of old-growth present 

is similar to the northern subspecies of western juniper, 

probably representing about 3 to 5 percent of the total 

woodland area. This is an approximation because past 

inventories have not distinguished between pre- and post 

settlement sites. For some ecological provinces the total may 

be higher. 

There is some commonality between old-growth woodlands across provinces. However, the amount of old-growth 

present, woodland structure, where woodlands occur, and 

the environmental conditions that support these woodlands 

vary between provinces. There are two general conditions 

in which old-growth most commonly occurs in the Great 

Basin of Nevada and Utah. The first of these categories are 

old-growth locations with shallow soils, rocky conditions, 

and steep topography that were relatively fire safe prior to 

recent tree expansion. These physical factors reduced the 

occurrence of fire allowing for some form of old -growth 

structure to develop. However, these combination of site 

factors occur over a wide range of elevation, topography, and 

environmental conditions that affect the structure, function, 

and appearance ofthe associated old-growth woodlands. As 

a result this is the most variable category of old-growth 

woodladds found in the region. With the recent expansion of 

the woodlands many of these old -growth locations are now 

succumbing to crown fires carried by the increased density 

of younger trees (Gruell, this symposium). 

The second type of site resulting in old-growth woodlands 

are sites where disturbances such as fire occur with some 

regularity but fuel levels are generally low enough to allow 

some tree survival, particularly for juniper forming communities similar to savanna in structure. These are generally 

lower elevation areas with relatively level to rolling terrain 

that prior to the recent tree expansion were open savannas 

with scattered older trees. Although the environmental 

heterogeneity is less than for the first type of site, considerable variation in conditions still exits within this category. 

The amount present also varies between ecological province. 

Here also the recent tree expansion, plus the increasing 

presence of invading annuals, is changing fuel conditions 

leading to the increasing loss of this type of old-growth by 

wildfire. 

High Desert and Mono Ecological 

Provinces 

These two provinces comprise the mountain ranges immediately east of the Sierra Nevada-Cascade Mountain chain 

and west of the Lahontan basin (fig. 1). Precipitation in this 

province comes almost entirely in the. winter. ~ith the 

exception ofa few scattered locations ofsmgleleafpmyon at 

381 
the far south end, the woodlands ofthe High Desert Ecological Province contain only juniper (West and others 1978). In 

Oregon it is the northern subspecies of western juniper. In 

the south of the High Desert Province Utah juniper dominates the woodlands. By contrast, the Mono Ecological 

Province is dominated by singleleaf pinyon, and over large 

areas the woodlands contain only singleleaf pinyon (West 

and others 1978, West and others, in press). Old-growth 

woodlands of both categories occur throughout both of these 

provinces. Although rare, some very old (1,000 years old 

plus) juniper old-growth woodlands are present in the Mono 

Ecological Province. 

The fire-protected category of old-growth sites appears to 

be more common than sites in the savanna category. Some 

large areas of old-growth juniper woodland occur on high 

mountain areas in the High Desert Ecological Province in 

Nevada that contain a good understory dominated by 

bluebunch wheatgrass (Tausch and others 1995). Large 

areas of old-growth pinyon woodlands, but with less understory (Robin Tausch and Robert Nowak, unpublished data), 

are found growing in similar environmental and topographic 

conditions in the Mono Ecological Province. In both provinces old-growth probably represents less than five percent 

of the total woodland area, but more locally its representation can be higher. 

Lahontan Ecological Province 

The Lahontan Basin is an open, low elevation area that 

extends north south through western Nevada from the 

Oregon border south to the Mojave Desert. Precipitation 

comes almost entirely in the winter. Woodlands on the 

mountain ranges in the northern half of this province are 

mostly Utah junipers, although scattered locations of western juniper and pinyon are present (Charlet 1996). In the 

southern portion the woodlands are either singleleafpinyon 

dominated, if it is present, or have only Utah juniper. Two 

notable examples of mountain ranges with woodlands containing only juniper are the Pilot and Cedar Mountains east 

of Mina, Nevada. Mountain ranges to the immediate north, 

south, east, and west are pinyon dominated. As pinyon 

migrated into this Province in the mid Holocene the Pilot 

and Cedar Mountains. 

Although both categories of old-growth woodlands occur 

in this ecological province, the savanna type is probably the 

most common. This occurs because of the aridity of the 

region from the rain-shadow of the Sierra Nevada Mountains, and the generally low elevations compared to surrounding provinces. Even in the higher elevation portions of 

the mountain ranges present, the woodlands are often more 

open with generally scattered trees. Maybe 10 percent of the 

woodlands in this province are old-growth. Essentially all 

the rest are post-settlement in age. 

High Central and High Calcareous 

Ecological Provinces 

These two Ecological Provinces, overall, represent the 

highest elevation areas of the Great Basin of Nevada and 

Utah. Some valley floors in the area exceed 7,000 ft and 

many of the highest peaks exceed 10,000 ft, with the highest 

382 

over 13,000 ft (West and others 1978). Geology of the High 

Central Ecological Province is mostly of igneous origin. 

Limber Pine is the only other relatively common conifer in 

the area. Geology of the High Calcareous Ecological Province is mostly of sedimentary origin with a high abundance 

oflimestone and dolomite present. This latter province has 

several species of conifer that are common in addition to 

pinyon and juniper (Charlet 1996). 

Juniper was probably very restricted in its distribution, 

and possibly absent in much of the area, during the Pleistocene. Pinyon was entirely absent, not arriving in the area 

until or after about 6,000 years B.P. (Nowak and others 

1994a,b). The majority of the old-growth in these two 

provinces is in the first category, and found most often on 

steep mountain slopes, generally with south and west aspects. This old-growth is predominantly pinyon dominated 

or pure pinyon. Some isolated locations of juniper oldgrowth are present on these upper elevations. Some Rocky 

Mountain junipers are scattered through the High Calcareous Ecological Province. This species often occurs along 

stream channels and in the highest elevations of the woodlands. Savanna type old-growth on the Bajadas and lower 

foothills are predominantly juniper dominated or only juniper is present. Old-growth of any type is rare, probably less 

than three percent of the total. All types of old-growth are 

increasingly at risk for loss by wildfire from both the recent 

increase in tree density and dominance, and the increasing 

prevalence of exotic annuals, particularly cheatgrass. 

Bonneville Ecological Province 

The Bonneville Basin is the eastern equivalent of the 

Lahontan Basin in the west. During the Pleistocene this 

basin had the largest lake in the region, Lake Bonneville. 

Shad scale desert covers large areas, isolating the mountain 

ranges that are present. This area is also rainshadowed by 

the higher mountains to the west. Summer precipitation 

increases in importance eastward across the region. The 

majority of the woodlands in this area have a high presence 

of juniper. Extensive areas of juniper savanna are present, 

and a large part ofit is old-growth. Most of the old-growth is 

in the savanna category. Old-growth in the first category has 

rare occurrences on the higher mountains in the region. On 

average, the oldest pinyon and juniper in the Great Basin of 

Nevada and Utah are generally found in this province 

(Tausch and others 1981). Old-growth may exceed 10 percent of the total woodland area in this province. In the 

eastern half of the province hybrids between singleleaf and 

Colorado pinyon are present. 

Humboldt and Raft River Ecological 

Provinces 

Both of these provinces represent a transition zone of 

generally decreasing elevation between the high basin and 

range topography to the south, and the Snake River Plains to 

the north. Woodlands in the Humboldt Ecological Province 

are almost exclusively juniper, mostly Utah to the south 

and western juniper to the north (West and others 1978, 

Charlet 1996). The scattered pinyon that are present in the 

Humboldt province are only along the southern fringe of 

USDA Forest Service Proceedings RMRS-P-9. 1999 
the area. The southern half of the Raft River Ecological 

Province has large areas of woodlands with mixed singleleaf 

pinyon and juniper. In the northern half the woodlands 

contain only juniper. 

Old-growth Utah juniper is rare in these provinces, probably less than three percent of the total. The majority of the 

rest of the woodlands are post-settlement in age. Both 

categories of old-growth are present but their relative abundance needs to be determined. 

White River Ecological Province 

This province is a transition of decreasing elevation 

southward from the higher mountains and valleys of eastern and central Nevada down to the Mojave Desert. The 

southeastern portion of this province can get about a third or 

more of its rainfall in the summer. Woodlands are found 

from the upper elevations of the mountains down to, and in 

some places in the eastern half, out onto the valley floors. 

Further west woodlands are more confined to the mid to 

upper elevations of the mountain ranges. Both categories of 

old-growth woodlands are present within this province. 

Large areas of former savanna on the valley floors and 

foothills have seen a strong increase in tree density from the 

recent expansion. Many of these areas are now experiencing 

intense crown fires that consume both the pre- and the postsettlement trees. 

The highest mountain ranges have areas of old-growth on 

steep, rocky slopes. The south ends of the White River and 

Lahontan Ecological Provinces represent some of the most 

environmentally variable woodlands in the region. They 

have the highest diversity of plant species in woodlands of 

the Great Basin of Nevada and Utah (Tueller and others 

1979, West and others 1978). This apparently results from 

their position oftransition between the high mountains and 

valleys to the north and the Mojave Desert to the south. 

Climatic fluctuations throughout the Pleistocene and the 

Holocene has resulted in the migration of many plant 

species through these provinces (Nowak and others 1994a,b). 

Wasatch Ecological Province 

This province includes the west slopes of the Wasatch 

Front and the mountain ranges immediately to the west. 

Woodlands in this province have considerable floristic affinity with the Wasatch and Rocky Mountains. Most of the 

pinyon present is Colorado pinyon with the presence of some 

hybrids with singleleaf (possibly California) pinyon in the 

western edge of the province. Pinyon is also present primarily in the southern half ofthe province. Juniper is the most 

common tree in the woodlands of the northern half. 

Old-growth is limited in this province, probably less than 

two percent of the total. The majority of what is present is 

probably in the first category of sites that are relatively safe 

from fire. 

Mojave Ecological Province 

Woodlands in this province exist on the upper elevations 

ofthe higher mountain ranges that are like islands scattered 

through a sea of desert. The lowest valley elevations in the 

USDA Forest Service Proceedings RMRS-P-9. 1999 

continental United States occur in this province, such as, 

Death Valley. Rainfall is almost exclusively in winter. Some 

of the valley locations in this province were refuges for 

singleleafpinyon during the Pleistocene (Nowak and others 

1994a,b). Despite the overall aridity of the region, all except 

the lowest elevations tend to be dominated by singleleaf 

pinyon. In addition to Utahjuniper the highest ranges, such 

as the Spring and Sheep Ranges, also have scattered locations of Rocky Mountain juniper in their woodlands. Oldgrowth of both the fire safe and savanna categories is 

present throughout the region. Old-growth tends to be more 

common on lower elevation ranges than higher elevation 

ranges where the recent tree expansion has been more 

dominant. The savanna type of old-growth may also be more 

common. Overall, the amount of old-growth is low, but 

unknown. A large part of this province is within the boundaries of the Nevada Test Site. 

Management Considerations __ _ 

Before we can address how we should manage old-growth 

woodlands in the Intermountain West we must ask the 

question what should these old-growth stands be managed 

for? Old-growth juniper and pinyon woodlands make up a 

small percentage of the juniper and pinyon woodland. They 

are structurally and topographically more complex than 

the younger more abundant woodlands, adding biological 

diversity to the landscape and providing an important source 

of habitat for many organisms. Many of these stands are 

also very esthetically pleasing providing recreational, cultural and spiritual opportunities. Kaufmann and others 

(1992) states; "old-growth provide us with a tremendous 

opportunity for retaining or enhancing biological features 

unique to old-growth ecosystems." We should evaluate fire 

policies influencing these old stands including both fire 

suppression and let burn. Recent changes in overs tory and! 

or understory can alter the response ofthese communities to 

fire. However, continued fire suppression in some woodlands 

may increase the potential for large stand replacement fires. 

Fuel woodcutting also appears to be a rather wasteful use of 

this limited resource, unless cutting is designed to remove 

postsettlement trees and restore presettlement stand 

structure. 

Studies are needed to determine and describe the range of 

old-growth characteristics throughout the Intermountain 

West. Mapping and inventorying old-growth woodlands is 

extremely important for developing management and landuse plans. Development of and old-growth woodland classification system used in inventories would prove helpful in 

developing management plans. We also need information on 

gap dynamics, tree mortality, and succession following disturbance. This information will allow us to predict how 

woodlands respond to disturbance. It will also allow us to 

evaluate pre- and postsettlement changes in community 

structure and composition that have occurred in old-growth 

stands, define desired future conditions, and develop management programs to restore or maintain old woodlands. 

Old-growth woodlands can not be managed on a single tree 

basis but only at the community and landscape levels to be 

successful. These old stands are an important landscape 

component in the Intermountain West, supporting many 

plant and animal species, and interacting with adjacent 

plant community types. 

383 
Acknowledgments 

On going research in the old-growth western juniper 

woodlands is being supported by USDr Bureau of Land 

Management Lakeview, Burns, Alturas and Prineville Districts, Modoc National Forest, The Nature Conservancy of 

Oregon, USDA Agricultural Research Service, and Oregon 

State University. 

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501-506. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Conversion of Shrub Steppe to Juniper 

Woodland 

Rick Miller 

Tony Svejcar 

Jeff Rose 

Abstract-Juniper woodlands are frequently treated generically 

in management, wildlife studies, and environmental issues. Western juniper grows on a broad variety of soils and terrain, creating a 

high degree of spatial variability in stand structure and function. 

Stand heterogeneity can also be attributed to temporal or successional differences in shrub steppe conversion to juniper woodlands. 

During conversion a threshold is crossed which moves the shrub 

steppe community to a new steady state driven by different ecological processes. It is important to recognize both spatial and temporal 

heterogeneity when evaluating habitat suitability, predicting potential resource problems related to stand development, developing 

management plans, and setting priorities. 

Over 8 million acres of sagebrush steppe are in various 

stages of conversion to western j uni per woodlands (J uniperus occidentalis spp. occidentalis) in the semi-arid Intermountain Northwest (Miller and Wigand 1994). The rapid 

conversion of shrub steppe to western juniper woodlands 

(Burkhardt and Tisdale 1976, Young and Evans 1981, Miller 

and Rose 1995) has occurred across a wide variety of sagebrush communities, soils, and topography since the 1880s. 

The combination of spatial and temporal diversity creates a 

vast array of structurally different juniper communities, 

many of which are changing. J uni per woodland function and 

structure changes across different soils, landscape positions, and stages of development. During woodland development, low densities of trees in the early phases of encroachment add structural heterogeneity to shrub steppe 

community types. However, as woodlands continue to develop, tree function changes with size, distribution, and 

density. As woodland function and structure shift across 

varying landscapes and stages of development there are 

significant affects on community com position, diversity, and 

associated soils. Wildlife habitat suitability is also altered 

across time and space. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Departm.ent of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Rick Miller, Professor of Range Ecology, EOARC, Oregon State University, 

HC71, 4.51, Hwy 205, Burns, OR 97720. Tony Svejcar, Research Leaders 

USDA Agriculture Research Service, EOARC. Jeff Rose, Research Assistant, 

EOARC, Oregon State University. 

Acknowledgements: On going research in the old-growth western juniper 

woodlands is being supported by USDI Bureau of Land Management 

Lakeview, Burns, Alturas and Prineville Districts, Modoc National Forest, 

The Nature Conservancy, USDA Agricultural Research Service, and Oregon 

State University. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Juniper woodlands have often been treated generically 

during the development of management plans, defining 

wildlife values, and debates relating to the benefits or 

problems of these communities. The illusion of a homogeneous landscape is created as tree canopies close. The 

majority of wildlife studies and inventories in the Intermountain West have not considered the wide variation of 

structure and function of woodlands across community types 

and in different successional stages. Spatial and temporal 

heterogeneity generally have not been taken into account 

when considering the impacts of woodland development on 

erosion, loss of understory, or plant diversity. It is very 

important to identify the community type, stage of woodland development, and thresholds for developing management plans, setting priorities, determining the best management tools to use, evaluating wildlife habitat values, and 

determining the effects of no action. 

This paper will present preliminary results and discuss 

several concepts relating to the conversion of shrub steppe 

communities to western juniper woodlands. Specific objectives are to: (1) describe the different phases of shrub steppe 

conversion to juniper woodland, (2) discuss thresholds that 

are crossed during the conversion of shrub steppe to woodland, and (3) describe the affects of spatial variability on 

woodland development. 

Study Area ________ _ 

The conversion of shrub steppe to juniper woodlands was 

studied in both the High Desert and Klamath ecological 

provinces of eastern Oregon and northeastern California 

(fig. 1). Climate is cool and semiarid, characteristic of the 

northern Great Basin. Annual precipitation in the western 

juniper woodland zone typically ranges from 12 to 16 inches. 

Most of the moisture is received as snow in November, 

December, and January and as rain in March through June. 

Summers are usually dry. Soils in these two provinces are 

primarily derived from igneous materials such as basalt, 

andesite and ryholite. The largest area of woodland conversion is in mountain big sagebrush (Artemisia tridentata spp. 

uaseyana) and low sagebrush (A. arbuscula) steppe communities. However, western juniper encroachment also occurs 

in basin big sagebrush (A. tridentata spp. tridentata), bitterbrush (Purshia tridentata), mountain mahogany (Cercocarpus ledifolius), aspen (Populus tremuloides), and riparian 

communities. 

385 
386 

Figure 1-Ecological provinces in 

the Intermountain northwest region 

where western juniper occurs (derived from Anderson 1956 and Bailey 

et al. 1994). 

•• ---Shrub Steppe---.... Ji 

s 

c: 

C\) c: e .2 C\) II) 

~ II) 

u C\) 

c: u -u 

>-:::J flU) 

C\) C\) 

c: > W"E: 

-0 

e 0 :::J-

~"O 

:::J C\) 0.: 

~ :::J 00'" 

C\) C\) 

ED:: 

j:: 

Perennial - Forb 

Grassland 

Shrub-Steppe 

Methods 

Plant community composition, and soils were measured 

in a 160 macroplots, 60 x 45 m, across the two ecological 

provinces. We collected a representative sample ofcommunity types characterizing this region within the western 

juniper belt in different stages of woodland conversion. 

Juniper cover was measured along three 60 m line intercepts 

within each macroplot. Tree density was recorded in three 

60 x 6 m rectangular plots. Shrub cover was measured along 

three 30 m line intercepts and density determined in 

30 x 2 m plots. Both density and cover of herbaceous species 

were recorded in 0.20 m2 plots placed at 3 m increments 

along the three 60 m transects. Soils were described for each 

macroplot and samples collected for textural analysis. Elevation, aspect, and slope were also measured. 

Discussion __________ _ 

Temporal Change 

Several thresholds may be crossed as juniper woodlands 

develop. Once a threshold is crossed the probability of a 

community returning to a previous state is very low. The 

conceptual model in figure 2 illustrates the conversion of 

shrub steppe communities to juniper woodland in the absence offire. The perennial forb-grassland and shrub steppe 

communities are a fire driven system. During the early 

phases of woodland development, transition is reversible . 

.--Juniper Woodland ---+-

Juniper 

H----- Fire Driven -------t"'~,,' 

H' h Juniper H' h L LOw .... --Ji~ Ig ~stablishmen~ Ig ...... f---------...:Ji .. ow 

High ...... f---------- Mean Fire Intervals ---------.Ji Low 

Figure 2-Conceptual diagram of changes in a shrub steppe community 

in the absence of fire (modeled after Archer 1989). In the absence of fire 

the abundance of shrubs decline as juniper trees gain dominance. The 

threshold has been crossed when understory fuels drop to a level where 

fire is unlikely to carry through the stand or generate enough heat to kill 

trees> 10ft tall. The probability of the woodland crossing the threshold and 

reverting back to shrub steppe is very low in the absence of a major 

disturbance or very costly inputs. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
However, by mid to late stages of transition a threshold is 

crossed where the reversal to shrub steppe communities is 

unlikely. Shrubs begin dying out as woodlands approach 

mid development, in mountain big sagebrush community 

types. As shrubs decline in the understory the probability of 

a fire event intense enough to kill large juniper trees rapidly 

declines. 

Presettlement fire return intervals in mountain big sagebrush were frequent enough to maintain shrub steppe community types. Fire return intervals in these communities 

usually ranged between 10 and 25 years (Houston 1973, 

Burkhardt and Tisdale 1976, Martin and Johnson 1979, 

Miller and Rose in press). Trees less than 10 ft tall are easily 

killed by fire (Bunting 1984). It usually requires 40 to 50 

years for a westernjuniper to attain this height in mountain 

big sagebrush community types (Miller and Rose 1995). The 

maximum hazard function (100 percent probability that a 

fire will occur within a defined time period) prior to 1880 was 

45 years in a mountain big sagebrush community type in 

south central Oregon (Miller, unpublished data). However, 

the maximum hazard function for many newly formed juniper woodlands is 1,000 years. In low sagebrush-Sandberg 

bluegrass (Poa sandbergii) community types tree establishment and growth rates are limited in the shallow heavy clay 

soils. One fire every 100 to 150 years were adequate to 

maintain a widely scattered stand of juniper in these 

communi ties. 

The state of woodland transition can be identified by 

structural characteristics of the woodland (table 1). Tree 

canopy cover and density alone have limited value as indicators of stand closure (the point where the site is fully 

occupied by juniper) since tree abundance is highly variable 

across community types. Sites with naturally low productivity will reach stand closure at lower juniper canopy cover and 

density than a more productive site. However, tree growth 

characteristics and shrub vigor are good indicators of the 

early stages of stand closure. Leader growth on dominant 

and understory trees is probably the best indicator for 

degree of stand closure for the site. The reduction in leader 

growth on trees less than 10 ft tall is due to intra-specific 

competition from larger neighboring trees. Prior to stand 

closure shrubs begin dying near the base and directly adjacent to large juniper trees. Shrubs begin thinning in the 

inner space during the early phases of stand closure (latemid to early late woodland development), about the same 

time as understory tree leader growth becomes suppressed. 

At this stage of juniper woodland development shrub steppe 

communi ty characteristics in the understory quickly change. 

During the later stages of woodland development tree recruitment declines due to changes in seed production and 

community structure. As intra-specific competition between 

trees increases, seed production declines and the ratio of 

male:female trees increases. This reduces seed rain from 

within the stand although birds, the primary seed dispersers of juniper berries, can easily bring in seed from outside 

sources. However, micro sites provided by shrubs for juniper 

seedling establishment decline during the later stages of 

woodland development. Shrubs are an important structural 

component for the germination and establishment of juniper 

seedlings (Miller and Rose 1995). 

Crossing the threshold in juniper woodlands results in a 

significant reduction in the role of fire. On many sites, 

crossing the threshold may result in a loss of native herbaceous species (fig. 3), the potential loss ofsurface soil, and the 

loss of mast crops for wildlife. However, site factors such as 

soil depth and texture, the presence of shallow hardpans, 

slope, and aspect influence the effects of juniper competition 

on understory vegetation and soils. Grazing and fire suppression are the two primary management activities that 

have influenced junipers' interaction with the herbaceous 

understory. Below about 5,000 feet in elevation, poor grazing management can hasten the abundance of exotic 

Table 1-Structural characteristics that change during the conversion of mountain big sagebrush community types to fully developed western juniper 

woodlands. 

Characteristics 

(Post settlement 

stands) Early Mid Late Closed 

Leader growth Good terminal and Good terminal and Good terminal growth, Good to reduced terminal 

(Dominant trees) lateral growth lateral growth reduced lateral growth growth, lateral growth absent 

Tree Canopy Open, actively expanding Actively expanding, Canopy expansion greatly Canopy expansion stabilized, 

cover::; 5 percent cover 6 to 20 percent reduced, cover 21-35 percent cover> 35 percent 

Crown Lift Absent Absent Lower limbs beginning to die Lower limbs dead 

(Dominant Trees) (for productive sites) (for productive sites) 

Potential berry Low Moderate to High Low to Moderate Nearly absent 

production 

Potential High High Reduced Nearly absent 

Tree Recruitment 

Growth Good terminal and Good terminal and Greatly reduced terminal and Leader growth absent, some 

(Understory trees) lateral growth lateral growth lateral growth; reduced ring mortality, limited ring growth 

growth 

Shrub Layer Intact Nearly intact to dying canopies ~ 40 percent dead ~ 85 percent dead 

around dominant trees 

USDA Forest Service Proceedings RMRS-P-9. 1999 387 
100 shrubs 

-- - --- -~ 100 

80 80 

Q) 

(J~ Threshold 

C+=I 

ns 5i 60 60 ~ .. C! 

:::S:2 .c';f. 40 «'-' 40 

20 20 

0 0 

+-+ early • ~ mid • ~ late • ~ closed+-+ 

- Juniper Woodland Development----. 

Figure 3-Conceptual model illustrating the change in abundance of 

perennial grasses and shrubs during the conversion of shrub steppe to 

juniper woodland. The affect of juniper woodland succession on grass 

abundance is variable, dependent upon site factors (soils, aspect, etc.). 

The shaded area between the perennial grass line, during mid to closed 

stages of woodland development, illustrate the different levels of grass 

abundance that occurs across different sites. 

annuals. Above 5,000 feet exotic annuals are less abundant, 

but poor grazing management can reduce herbaceous cover 

and increase the amount of bare ground. The loss of soil 

during woodland conversion is particularly acute on south 

slopes that have been improperly grazed. 

As woodlands develop, the threshold of habitat suitability 

for certain wildlife species is also crossed. Horned larks, 

vesper sparrows, brewers sparrows, sage thrashers, and 

sage grouse decline during the mid to late stages of woodland 

development (Eastern Oregon Agricultural Research Center unpublished data). The lowest abundance of mountain 

bluebirds occurred in closedjuniper stands in contrast to the 

highest counts that occurred in open old growth juniper 

woodlands, and sagebrush steppe communities adjacent to 

old growth woodlands. 

Spatial 

Western juniper occurs across a wide array of soils within 

the two provinces including Durargids and Haplargids commonly characterizing the low sage community types, and 

Druixerolls, Argixerolls and Haploxerolls in the mountain 

big sagebrush community types. Soil suborders vary from 

aridic, lithic, typic and pachic and soil temperature regimes 

range from mesic to frigid. Soil textures vary from 80 percent 

clay content on juniper low sage tablelands to 80 percent 

sand in the aeolian sand region. Soil depths vary from zero 

on fractured rock to deep Haploxerolls commonly found on 

mountain big sagebrush/snowberry (Symphoricarpos 

oreophilis)/Columbia needlegrass and aspen community 

types. 

388 

Western juniper occurs across a large number of plant 

community types in the High Desert and Klamath ecological 

provinces (table 2). Plant community structure in fully 

developed woodlands varies across and within community 

types. Tree canopy cover measured within community types 

for fully developed woodlands ranged between 20 percent in 

low sagebrush/Sandberg bluegrass to over 90 percent in 

aspen community types (fig. 4). Vertical lines in figure 4 are 

anticipated ranges of maximum juniper cover within different community types based upon our observations. Tree 

numbers were also highly variable in fully developed woodlands across community types (fig. 5). Density of mature 

trees varied from 50 per acre in low sagebrush to over 300 per 

acre in mountain big sagebrush/Columbia needlegrass. In 

mountain big sagebrush community types with clay to clay 

loam soils and argillic horizons, average densities of mature 

trees typically ranged between 120 to 200 per acre. Tree 

densities were usually over 250 per acre on deep loams with 

weak to absent argillic horizons. These productive community types are typically positioned on northerly aspects. 

Densities of mature juniper trees in aspen stands converted 

to juniper woodland were over 700 per acre. 

We are currently analyzing the herbaceous cover data 

across the plots to determine the relationship of juniper and 

environmental variables on understory composition and 

structure. A consistent response across all plots is the 

decline in mountain big sagebrush with the increase in 

western juniper (fig. 3). However, preliminary results indicate the response of perennial grass and forb cover to juni per 

cover is inconsistent across and within community types. 

The shaded area in Figure 3 represents the full range of 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Table 2-Plant community types commonly invaded by western juniper in the High 

Desert and Klamath ecological provinces in southeastern Oregon and 

northeastern California. 

Dominant shrub 

Co-dominant 

shrub Dominant grass 

Low sagebrush 

Low sagebrush 

Low sagebrush 

Basin big sagebrush 

Sandberg bluegrass 

Bluebunch wheatgrass 

Idaho fescue 

Basin wildrye 

Thurber needlegrass 

Thurber needlegrass 

Bluebunch wheatgrass 

Idaho fescue 

Basin big sagebrush 

Mountain big sagebrush 

Mountain big sagebrush 

Mountain big sagebrush 

Mountain big sagebrush 

Mountain big sagebrush 

Mountain big sagebrush 

Mountain big sagebrush 

Mountain brg sagebrush 

Mountain big sagebrush 

Curleaf mountain mahogany 

Aspen 

Bitterbrush 

Bitterbrush 

Bitterbrush 

Snowberry 

Snowberry 

Columbia needlegrass 

Thurber needlegrass 

Bluebunch wheatgrass 

Idaho fescue 

Idaho fescue 

Columbia needlegrass 

Idaho fescue 

400 

CI) 

... 300 I 

u 

cu 

-... 

CI) 200 ,Sf 

c I :::J 

.., 

100 l 

o 

Posa Agsp Feld Stth Agsp Feld Stco 

A~r ArtN 

Community Types 

Figure 4-Percent juniper canopy cover for fully 

developed woodlands across different community 

types. Communities were designated as fully developed woodlands based on the criteria in table 1. 

Each point represents one 60 x 45 m plot. Vertical 

lines drawn through the points are anticipated ranges 

of maximum juniper canopy cover for each community type. 

400 

300 

200 

100 

changes in perennial grass abundance influenced by juniper 

woodland development across different sites. As mentioned 

previously, site variables appear to influence the impact of 

increasing juniper cover on perennial grass cover. Perennial 

grass cover was little affected by increasing juniper dominance on deep well-drained soils. This situation is most 

common on north aspects with deep clay loam to loamy 

Pachic Argixerolls and Pachic Haploxerolls characterized by 

mountain big sagebrush/Idaho fescue (Festuca idahoensis) 

and mountain big sagebrush/Columbia needlegrass community types. However, herbaceous cover was greatly reduced 

USDA Forest Service Proceedings RMRS-P-9. 1999 

400 

CI) 300 I lI 

CJ 

cu 

-... 

CI) 200 ,SI f 

c 

::J 

.., 100 l 

o 

Posa Agsp Feid Stth Agsp Feid Stco 

Arar ArtN 

Community Types 

Figure 5-0ensity of mature juniper trees (near full 

height) for fully developed woodlands across different community types. Criteria in able 1 were used to 

determine stands that were fully developed woodlands. Points are means and lines represent range 

between maximum and minimum points occurring 

on plots within types. 

400 

300 

200 

100 

in community types with restricted cemented ash layers. 

Herbaceous cover was reduced to 2 percent on a mountain 

big sagebrushlThurber needlegrass (Stipa thurberiana) site 

growing on clay loam soils 14 to 16 inches deep, underlain by 

a thick, cemented silicic ash layer of rhyolite and rhyodacite 

composition (Bates et a1. in press). Following release from 

tree competition, perennial herbaceous cover on this site 

increased 300 percent in the first two years. On other 

mountain big sagebrush/Thurber needlegrass community 

types, total herbaceous cover in closed woodlands was typically less than half compared to cover values in the early 

389 
stages of woodland development. In pinyon-juniper woodlands an inverse relationship between tree canopy cover and 

understory cover and biomass have been reported (Jameson 

1967, Clary 1971, Clary and Jameson 1981, Tausch et al. 

1981, Pieper 1990). For western juniper it appears this 

relationship is dependent upon certain site variables. 

Conclusions -------------------------------- Western juniper occurs across a broad variety of soils and 

terrain creating a high degree of stand heterogeneity in 

structure, composition, function, and varying effects on 

ecological processes such as hydrology and nutrient cycling. 

Stand variability can also be attributed to varying stages of 

woodland development since western juniper expansion is 

relatively recent (within the last 120 years). As shrub steppe 

communities are converted to juniper woodlands community structure, composition, function, processes, and wildlife 

habitat suitability are altered. During conversion a threshold is crossed which moves communities to new steady states 

driven by different ecological processes. Once a threshold 

has been crossed it becomes significantly more difficult to 

return communities to previous states. The identification of 

spatial and temporal heterogeneity in westernjuniperwoodlands is extremely important when evaluating potential 

resource problems, determining wildlife habitat values, developing management plans, and setting realistic goals and 

time frames. 

References ---------------------------------- Anderson, E. W. 1956. Some soil-plant relationships in eastern 

Oregon. Journal of Range Management 9:171-175. 

Archer, S. 1989. Have southern Texas savannas been converted to 

woodlands in recent history? The American Naturalist 134: 

545-561. 

Bailey, R. B. and others. 1994. Ecoregions and subregions of the 

United States. Map USDA Forest Service, Washington DC. 

390 

Bates, J. D. 1996. Understory vegetation response and nitrogen 

cycling following cutting of western juniper. Ph.D. Dissertation, 

Oregon State University, Corvallis. 

Bunting, S. 1984. Prescribed burning of live standing western 

juniper and post-burning succession. Pages 69-73 in T.E. Bedell, 

compiler, Oregon State University Extension Service. Proceedings of western juniper short course. October, 15-16, Bend, Oregon. 

Burkhardt, J. W., and E. W. Tisdale. 1976. Causes of juniper 

invasion in southwestern Idaho. Ecology 76:2-484. 

Clary, W. P. 1971. Effects of Utah juniper removal on herbage yields 

from Springerville soils. Journal of Range Management 24: 

373-378. 

Clary, W. P. and D. A Jameson. 1981. Herbage production following 

tree and shrub removal in the pinyon-juniper type of Arizona. 

Journal of Range Management 26:70-71. 

Houston, D. B. 1973. Wildfires in northern Yellowstone National 

Park. Ecology 54:1109-1117. 

Jameson, D. A 1967. The relationship oftree overstory and herbaceous understory vegetation. Journal of Range Management 

20:247-249 

Martin, R. E., and A H. Johnson. 1979. Fire management of Lava 

Beds National Monument. Pages 1209-1217 in R. E. Linn, editor. 

Proceedings of the First Conference of Science and Research in 

the National Parks. USDI National Parks Service. Transactions 

Proc. Serial No.5. 

Miller, R. F. and J. A Rose. 1995. Historic expansion of Juniperus 

occidentalis (western juniper) in southeastern Oregon. Great 

Basin Naturalist 55:37-45. 

Miller, R. F., T. J. Svejcar, and N. E. West. 1994. Implications of 

livestock grazing in the Intermountain sagebrush region: plant 

composition. Pages 101-146 in M. Vavra, W. A Laycock, and 

R. D. Pieper, editors. Ecological Implications of Livestock Herbivory in the West. Society for Range Management, Denver, 

Colorado, USA 

Miller, R. F., and P. E. Wigand. 1994. Holocene changes in semiarid 

pinyon-juniper woodlands. BioScience 44:465-474. 

Miller, R. F., and J. A Rose. (1998). Fire History and Juniperus 

occidentalis Hook. encroachment in Artemisia steppe. Journal of 

Range Management (submitted). 

Tausch, R. J., N. E. West, and A A Nabi. 1981. Tree age and 

dominance patterns in Great Basin pinyon-juniper woodlands. 

Journal of Range Management. 34:259-264. 

Young, J. A, and R. A Evans. 1981. Demography and fire history 

of a western juniper stand. Journal of Range Management. 

34:501-506. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Return Interval for Pinyon-Juniper Following 

Fire in the Green River Corridor, Near Dutch 

John, Utah 

Sherel Goodrich 

Brian Barber 

Abstract - Colorado pinyon (Pinus edulis Engelm.) and Utah 

juniper (Juniperus osteosperma [Torr.] Little) are returning, following three fires, in the Green River corridor, Daggett County, Utah. 

It will take several decades to over a century before pinyon-juniper 

will dominate plant communities following fire. Recognizing this 

interval can facilitate planning and management for a diversity of 

successional stages across the landscape of the Green River corridor. The long return interval indicates a rather small burning 

program could sustain diversity. The long return interval indicates 

long-term benefits and thus higher economic return for burning 

compared to treatments of shorter return interval for pinyon and 

juniper. 

The Green River corridor in Daggett County, Utah, represents the northern limit for Colorado pinyon (Pinus edulis 

Engelm.) near the Utah-Wyoming line. North of the Green 

River corridor, Colorado pinyon is uncommon and it is 

known to extend only a few miles into Wyoming. Utah 

juniper (Juniperus osteosperma [Torr.] Little) extends well 

into Wyoming where it forms stands without Colorado 

pinyon. In the Green River corridor, the two species commonly grow together, but Colorado pinyon often replaces 

Utah juniper over time especially on cool aspects where to 

some extent it is able to regenerate under its own shade or 

at least in small openings created by the death of old trees. 

In the Green River corridor 'as elsewhere in their range, 

Colorado pinyon and Utah juniper have great capacity to 

drive plant community dynamics. Without disturbance they 

displace other communities and form close stands across 

nearly all soil types and all geologic substrates within the 

thermal belt to which they are well adapted. Management of 

pinyon-juniper areas can be facilitated by an understanding 

of the return interval of these highly competitive plants 

following fire or other disturbance. Return of pinyon and 

juniper in three burns in the Green River corridor indicate 

the return interval following fire. 

The three burns are at Mustang Ridge (13 ha or 32 acres), 

Dripping Springs (56 ha or 138 acres), and Dutch John 

Canyon (82 ha or 203 acres). The burn at Dripping Springs 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Sherel Goodrich is Forest Ecologist, Ashley National Forest, Vernal, UT 

84078. Brian Barber at the time of his recent retirement was Fire Management Officer, Flaming Gorge District, Ashley National Forest, Dutch John, 

UT 84023. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

was aerially seeded with a mix of grasses of which crested 

wheatgrass established throughout the burn. The other two 

burns were not seeded. These burns are all within a radius 

of 4.8 km (3 miles) of the town of Dutch John where mean 

annual precipitation at the Flaming Gorge Weather Station 

is 31.75 cm (12.50 inches) (Ashcroft and others 1992). 

Methods and Results 

A search of files at the Supervisor's Office, Ashley National Forest, Vernal, UT, indicated the Mustang Ridge fire 

burned about 1950 (Plummer 1965, 1972; Webster 1972), 

and the Dripping Springs fire burned in 1959 (Plummer 

1965). The burn in Dutch John Canyon was older. It was not 

included in notes by Plummer or Webster cited above. This 

burn was visited in 1996, and a search was made for fire 

scars on pinyon trees that had survived the fire. A number 

of fire-scared pinyon trees were found. Cross sections were 

taken by chain saw from three of the scared trees. One tree 

was near the bottom ofthe canyon. One was from about midslope on the east side ofthe canyon, and the other was taken 

from near the top ofthe east side ofthe canyon. All were from 

the margin of the burn. No live, scared trees were found 

toward the center ofthe burn. This was a stand replacing fire 

with few or no survivors except at the margin of the burn. 

Also, cross sections of a few trees that had obviously regenerated since the fire were taken between ground level and 

about 30 em (1 foot) above ground level. 

With the aid ofa 7-30 power binocular scope, annual rings 

of the cross sections were counted. Rings from the scar 

outward to the cambium were used to indicate the year ofthe 

fire. Ring counts from the three scared cross sections indicated the fire had burned 101, 102, and 103 years before 

1996. These dates were close enough together to consider a 

single burn for the area of just over 100 years ago. Growth of 

the trees might have been suppressed for a year or two 

following the fire. However, the fire is indicated to have 

burned in the 1890's. Procedures for dating the fire from 

annual rings of trees with fire scares is similar to those 

discussed by Arno and Sneck (1997). Annual rings from cross 

sections indicated live trees within the burn were 30 to 95 

years old. There were smaller trees present than the one 

dated at 30 years, but the 95 year old tree was one of the 

largest ones in the burn. Since the cross section was taken 

above ground level, this tree was somewhat older than 95 

years. It was adjacent to the burnt stump of a large tree 

burned in the fire. It is highly unlikely that it was a survivor 

from the fire. This tree also indicates the fire to have been in 

the 1890's. 

391 
Return of trees to these burns was determined by measurements, ocular estimates, and by photographs. Counts in 

six 1.83 by 50.78 m (0.0093 ha) plots in 1997 indicated 

between 287 and 358 trees per hectare in some places in the 

Mustang Ridge Burn. However, these plots indicated only 

71 to 143 trees per hectare were over 1 m tall. The large 

n umber of seedlings and small trees indicate am uch greater 

dominance of pinyon-juniper in the next few decades. In 

some areas of the Dripping Springs and Mustang Ridge 

burns, tree density was less than five trees per hectare at 38 

and 47 years postfire, respectively. After about 100 years, 

density of trees in the Dutch John Canyon Burn varied from 

few to many per hectare depending on location within the 

fire. Size and age structure of these trees indicated recruitment of all ages within the burn. Overall canopy cover of 

pinyon and juniper was less than 1 percent 38 years post fire 

at Dripping Springs, about 2 percent -47 years postfire at 

Mustang Ridge, and between 5 and 15 percent about 100 

years postfire at Dutch John Canyon. 

Discussion -------------------------------- A slow return rate is indicated for the first 40 to 50 years 

with an apparent accelerated rate in later years. A slow rate 

of return is also indicated by Despain (1987) in the first 20 

to 30 years following burning and seeding in Arizona. Also, 

Ronco (1987) suggested stand density of pinyon-j uni per does 

not increase appreciably until 45 years after disturbance. 

The successional patterns of the Green River corridor appear similar to the model of Erdman (1970) which shows 

shrub/open tree communities at 100 years postfire. 

Nearly all pinyon-juniper trees within the perimeter of 

these fires were killed. There were a few islands of survivors 

in the Dutch John Canyon fire on rocky outcrops and at 

topographic breaks. It appears that few seeds of either 

species survived the fires, or they failed to germinate or at 

least failed to establish. However, the 95 year old tree that 

had regenerated in the burn indicates at least a few trees 

established soon after the fire. Return of trees to the burns 

appears to be a largely a function of seed spread from the 

edge of the burns, and as indicated by Balda (1987), they are 

heavily dependent on birds to disperse their propagules. 

This appears to be a major factor in return of these trees to 

the center of large burns. Also, the few trees that establish 

soon after fire appear to be a source of seed within burns. 

This discussion is most applicable to burns over 8 ha (20 

acres). Return of pinyon and juniper to smaller burns and 

especially the margins of burns could be more rapid. Huber 

and others (these proceedings) found a stand with crown 

cover of pinyon-juniper at about 60 percent. This appeared 

to be at the margin of a small burn of about 140 years old 

where seeding establishment was rapid. 

Return of trees to the burns at Dripping Springs, Mustang 

Ridge, and Dutch John Canyon indicates it will take 100 years 

or more for plant communities to progress to a shrub/open tree 

status. Also indicated is 150 to 200 years to achieve preburn 

density oftrees and greater than 200 years to achieve mature 

and old stages of succession. For north-central Arizona, Tress 

and Klopatek (1987) estimated 215 years to complete a sere in 

pinyon-juniperwoodlands. Erdman (1970) indicated 300 years 

from fire to climax forest. Barney and Frischknecht (1974) 

392 

found woodlands well developed 85 to 90 years after fire in 

the Great Basin. However, well developed in this case seems 

to apply to young stands with aspect dominance but not the 

end of a sere. 

Management Implications 

The burns reported in this paper and other wildfires and 

prescribed burns of the Green River corridor were stand 

replacement fires. Underburning does not seem a realistic 

option. The stands are difficult to burn until conditions are 

severe enough to create crown fires. Recognizing the return 

interval for pinyon-juniper after stand replacement fires can 

facilitate management oflandscapes where certain levels of 

different successional stages are desired across a landscape. 

Under a draft concept of "properly functioning condition," 

Amundson and others (1996) indicated a proper landscape 

mix of successional stages for pinyon-juniper woodlands in 

the Intermountain Region of the Forest Service as follows: 

10 percent grass/forb, 10 percent seeding/sapling, 20 percent 

young forest, 20 percent mid-aged forest, 20 percent mature 

forest, and 20 percent old forest. For the Green River corridor, it appears that it would require a fire frequency of 

greater than 200 years to achieve closed, mature pinyonjuniper stands in burns of greater than about 8 ha (20 acres). 

Fire interval would have to exceed 100 years to achieve and 

maintain scattered trees in plant communities. Fire intervals of 10 to 30 years would not allow for succession beyond 

a grass/shrub stage in which trees over 1 m tall would be 

mostly excluded. 

The rate of succession indicates maintenance of earlier 

successional stages can be achieved with a small annual 

burning program. For a 8,100 ha (20,000 acre) landscape 

with a fire interval of 100 years, only 80 ha (200 acres) of 

burning per year could maintain the landscape in early to 

mid-seral stages. If 40 percent of the landscape was desired 

with mature and old stands, an average of 50 ha (120 acres) 

of burning per year is indicated to maintain this condition. 

The long return interval greatly facilitates economic return 

for prescribed fire, and it indicates a relatively small burning program to achieve a desired mix of successional stages. 

References -------------------------------- Amundson,J.; Ogle, K.; Winward, A. H.; and others. 1996. Properly 

functioning condition. Draft Process - Version. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Intermountain Region. 31 p. 

Arno, S. F.; Sneck, K. M.1977. A method for determining fire history 

in coniferous forest of the Mountain West. Gen. Tech. Rep. INT42. Ogden, UT: U. S. Department of Agriculture, Forest Service, 

Intermountain Forest and Range Experiment Station. 28 p. 

Ashcroft, G. L.; Jensen, D. T.; Brown, J. L. 1992. Utah climate. 

Logan, UT: Utah State University, Utah Climate Center. 125 p. 

Balda, R. P. 1987. Avian impacts on pinyon-juniper woodlands. In 

Everett, R. L., compiler. Proceedings-pinyon-juniper conference; 

1986 January 13-16; Reno, NV: Gen. Tech. Rep. INT-215. Ogden, 

UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 525-533. 

Barney, M.A.; Frischknecht,N. C.1974. Vegetation changes following fire in the pinyon-juniper type of west-central Utah. J. Range 

Manage. 27: 91-96. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Despain, D. W. 1987. History and results of prescribed burning of 

pinyon-juniper woodland on the Hualapai Indian Reservation in 

Arizona. In Everett, R. L., compiler. Proceedings-pinyon-juniper 

conference; 1986 January 13-16; Reno, NV: Gen. Tech. Rep. INT215. Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 145-151. 

Erdman, J. A 1970. Pinyon-juniper succession after natural fires in 

residual soils of Mesa Verde, Colorado. Brigham Young University Science Bulletin Biological Series 11. Provo, UT: Brigham 

Young University. 24 p. 

Huber, A; Goodrich, S.; Anderson, K. These proceedings. Diversity 

with successional status in the pinyon-juniper/mountain mahoganylbluebunch wheatgrass community type near DutchJohn, 

Utah. In: Monsen, Stephen B.; Stevens, Richard; Tausch, Robin 

J.; Miller, Rick; Goodrich, Sherel, comps. 1998. Proceedings: 

ecology and management of pinyon-juniper communities within 

the Interior West; 1997 September 15-18; Provo, UT. Proc. 

RMRS-P-OOO. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Research Station. 

Plummer, A P. 1965. Correspondence on-file at: U.S. Department of 

Agriculture, Forest Service, Ashley National Forest Supervisors 

Office, Vernal, UT; 2060, study folder 6-8. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Plummer, A P.1972. Correspondence on file at: U.S. Department of 

Agriculture, Forest Service, Ashley National Forest Supervisors 

Office, Vernal, UT: 2060, study folder 6-8. 

Ronco, F., Jr. 1987. Stand structure and function of pinyon-juniper 

woodlands. In Everett, R. 1., compiler. Proceedings-pinyon-juniper conference; 1986 January 13-16; Reno, NV: Gen. Tech. Rep. 

INT-215. Ogden, UT: U.S. Department of Agriculture, Forest 

Service, Intermountain Research Station: 14-22. 

Tress, J. A, Jr.; Klopatek, J. M. 1987. Successional changes in 

community structure of pinyon-juniper woodlands on northcentral Arizona. In Everett, R. 1., compiler. Proceedings-pinyonjuniper conference; 1986 January 13-16; Reno, NV: Gen. Tech. 

Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 80-85. 

Webster, R. P. 1972. Environmental analysis report, Dutch John 

habitat improvement. On file at: U.S. Department of Agriculture, 

Forest Service, Ashley National Forest Supervisors Office, Vernal, UT; 2060, study folder 6-8. 

393 
Implications of Weedy Species in 

Management and Restoration of Pinyon 

and Juniper Woodlands 

Tony Svejcar 

Ahstract-A survey of the literature was done to determine if the 

presence of a weedy species is a short-term annoyance or a long-term 

threat on pinyon-juniper lands. The conclusion is that situations 

differ with no "cookbook" solutions for managers. Six-step guidelines will help managers find answers for site-specific questions. 

Rangeland weeds have attracted an increasing level of 

attention during recent years. There is concern over potential weed problems that may result from woodland (juniper 

or pinyon/juniper) conversion projects. In spite of the interest in both rangeland weeds and woodland conversion 

projects, I found surprisingly little research that specifically addresses weed problems in woodlands. Much of the 

work was more focused on control of woody species rather 

than the weeds that might follow restoration efforts. Young 

and others (1985) pointed out that juniper control methods 

would influence subsequent weed controVrevegetation 

options in the understory. If standing dead trees were left 

in place (for example, using herbicides or fire) there are 

physical limitations to the use of weed control and seeding 

equipment. For example, in a formerly dense woodland the 

dead canopy might make it impossible to use ground-seeding 

equipment. 

Cheatgrass (Bromus tectorum L.) has probably received 

more attention than any other weedy species that occurs in 

woodlands. So I will try to summarize the literature results 

for this species. In this paper I will: 1) present some of the 

reasons why woodland conversion projects pose the risk of 

weed invasion, 2) discuss the role of cheatgrass in woodland 

conversion, and 3) suggest several planning steps where 

weeds are considered in a larger ecological context. 

Why Should Weeds be a 

Concern? 

Woodland tree species, junipers in particular, are very 

effective at using soil resources. Using field data in conjunction with a simulation model, Angell and Miller (1994) 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Tony Svejcar is Supervisory Rangeland Scientist, USDA-Agricultural 

Research Service, Eastern Oregon Agricultural Research Center, HC 71 4.51 

Hwy 205, Burns 97720. The Eastern Oregon Agricultural Research Center is 

operated jointly by USDA-ARS and Oregon State University. 

394 

estimated that western juniper would use about 44 percent 

of the total precipitation in a year that received 32.0 em 

(12.6 inches). They assumed the site was stocked at 75 trees 

per ha (30 per acre) and that the leaf area index was 1.6. The 

effect ofthejuniper stand was to reduce precipitation available to other species to about 18 cm (7 inches). Seventy-five 

trees per hectare is not a particularly dense juniper stand. 

These authors point out that juniper may also intensify 

drought effects during dry years, and create site-water 

deficits early in the growing season. These conclusions were 

confirmed by Bates and others (1998), who found that soil 

moisture and nitrogen availability were much higher in cut 

woodlands, compared to those uncut. In a pinyon (Pinus 

monophylla Torr. & Trem) woodland, Everett and Thran 

(1992) found that about half ofthe total site N was contained 

in above-ground tree biomass and half in soil. Thus, the 

pinyon sequestered a major portion of site N, which would 

no longer be available to other species. 

The fact that woodland trees use a good deal of the 

resources on a site actually provides a degree of protection 

against weed invasions. Unfortunately, the tree dominance 

also tends to reduce the diversity and productivity of understory species (Bates and others 1998). The potential risk to 

woodland conversion projects is that an opportunistic weedy 

species will take advantage of the additional resources more 

quickly than desirable species (either existing or seeded 

species). The challenge is to determine whether the presence 

of a weedy species is a short-term annoyance or a long-term 

threat. 

Cheatgrass and Others ____ _ 

As mentioned earlier, there is more research information 

available on cheatgrass than on any other weedy species 

associated with North American woodlands. Much of this 

research has dealt with vegetation dynamics after a woodland fire. Barney and Frischknecht (1974) identified a weedy 

annual stage that peaked within 3 to 4 years after a fire, 

followed by several stages with differing mixes of perennial 

grasses, forbs, and shrubs. The change in cheatgrass cover 

values was dramatic ranging from 12.6 percent in 3-year-old 

burns to less than 1.0 percent in burns older than 22 years. 

A similar pattern was identified by Erdman (1970) in southwestern Colorado. The pattern may be similar with chaining. Working in central Utah, Davis and Harper (1990) 

measured a high density of both cheatgrass and burr buttercup (Ranunculus testiculatus) immediately after chaining 

on a pinyon juniper site. However, by the third year after 

chaining, the density of both species had declined by 85 

percent or more compared to the initial year values. In this 

USDA Forest Service Proceedings RMRS-P-9. 1999 
study, the density of seeded perennials increased over the 

3-year period. Evans and Young (1985) measured a dramatic 

increase in standing crops of cheatgrass (from near zero to 

1400 kg/ha) after controlling juniper with picloram pellets. 

Cheatgrass frequency declined in the treated areas over a 

7 -year period, but there was a continual increase in frequency of medusahead (Taeniatherum asperum). 

There is a body of research that shows weedy annuals, 

cheatgrass in particular, can increase immediately after 

woodland trees are killed, whether it be by fire, chaining, or 

herbicides. Much of the research indicates that this response will be transient, or that it may not even occur. For 

example, Barney and Frischknecht (1974) point out that 

the annual stage may be by-passed in areas that have good 

cover of perennial herbaceous species prior to burning. In 

central Oregon, Quincey (1984) stratified fire response of 

juniper woodlands into dry and moist sites. Dry sites contained cheatgrass prior to burning, and the increase persisted for 20 years in some cases. On the moist sites, perennial grasses dominated the unburned vegetation with little 

cheatgrass present. The moist sites did not have a fireinduced increase in cheatgrass. These results suggest that 

responses to woodland conversion projects will be sitespecific and depend heavily on the initial floristics of each 

plant community (Everett and Ward 1984, Koniak 1985). 

Although cheatgrass is the weed species mentioned most 

frequently in the literature, it certainly is not the only weed 

of concern in woodlands. There is presently an on-going 

invasion of diffuse and spotted knapweeds (Centaurea diffusa 

and C. maculosa, respectively) in upland sites and Russian 

knapweed (C. repens) in the moister sites (Lee Eddleman, 

personal communication). There are many other alien species that have the potential to invade woodlands. 

Principles and Planning ____ _ 

There are many variables that interact to influence the 

threat weeds pose on any given piece of rangeland. Every 

situation will be different and few "cookbook" answers will 

be available. However, there are general principles that will 

prove useful and every manager can develop site-specific 

information that will aid their future decisions; this approach is really adaptive-management. 

I would suggest everyone become familiar with the old 

ecological concepts of relay floristics and initial floristics. 

An orderly succession of plant communities is the basis of 

relay floristics. Each seral plant community relays the site 

to the next (see Barbour and others 1980, or other plant 

ecology texts for a more detailed discussion). The successional sequence is considered well defined and repeatable. In 

contrast, the implications of initial floristics is that succession of plant communities is not so easily defined and may 

not be repeatable (Barbour and others 1980). A number of 

factors may influence the course of succession. There is a 

degree of chance in which species are present on a site, which 

migrate quickly to the site after a disturbance, the type of 

year immediately following disturbance, etc. 

There may be elements of both initial and relay floristics 

that apply to any given situation. For example, there may be 

an annual phase that gives way to perennials over time 

(relay), but the annual phase may not occur if cheatgrass 

isn't a major component of pre-burn vegetation (initial 

USDA Forest Service Proceedings RMRS-P-9. 1999 

floristics). In a study of post-burn succession in pinyonjuniper stands, Everett and Ward (1984) suggest that elements of both relay and initial floristics were evident. 

There may be multiple successional pathways (Everett and 

Ward 1984) and successional patterns may vary among 

different sites (Koniak 1985). This led Koniak to conclude 

that it will be necessary to characterize a site (elevation, soil 

type, post-burn climate) and the disturbance (severity and 

timing) if community response is to be predicted. 

With appropriate planning and monitoring, land managers will be in a position to make informed decisions about 

woodland manipulation projects. Weeds should be considered within this larger framework. I would suggest the 

following six steps for a starting point: 

1. Develop clearly defined objectives. What are the land 

management goals for the site? What is the problem 

and what will be gained from a particular woodland 

treatment? Be as specific as possible. 

2. Describe the site. Parameters, such as land area, tree 

density, tree age, species composition, slope, aspect, 

soil depth, elevation, prior management, should be 

used in the decision-making process. The nature and 

initial floristics ofa site may give clues as to the risk of 

weed dominance. 

3. List the available management options. These will vary 

from one area to another, and by land ownership. 

These options should be evaluated for cost and effect 

on plant succession (next item). 

4. Consider how proposed treatments might influence 

the primary causes of succession. 

a. Site availability for colonization. What sites (actually microsites) might favor occupation by invader 

species? How will changes in density of woodland 

trees influence site availability? Different management tools have varying impacts, for example, prescribed fire will have a different effect on site availability than will cutting. Maybe a goal could be to 

red uce tree density to make sites available for other 

species, rather than total conversion of a woodland. 

b. Species availability. What species are on site or 

within easy dispersal distance? Are there species 

that tend to appear on a particular site after treatment (even if they are not obvious prior to treatment)? Do any of the species listed pose a major 

weed risk? Are species present that might close 

the site to weed invasion? 

c. Species performance. Are there site characteristics 

such as slope, soil texture, soil depth, aspect, that 

might favor a weedy species of concern? In many 

areas, drier south-facing slopes appear more susceptible to invasion by weedy species than do northfacing slopes. 

A more detailed discussion of successional weed management can be found in Sheley and others (1996). 

5. Prescribe site management after woodland management. Will seeding be necessary? Keep in mind that 

residual native species often respond favorably to woodland manipulation, even on sites that appear depleted. 

Is the site to be grazed, and ifso, what type of management will be necessary to allow recovery of understory 

species? 

395 
6. Develop a follow-up monitoring plan. How will adaptive management be accomplished if we don't keep 

track of our successes and failures? It is worthwhile 

setting goals for monitoring what you hope to accomplish. What is an appropriate monitoring system and 

time frame? How will the information be summarized 

and interpreted? Were weeds a problem? 

Although it is not specific to weeds, Aldon and others (1994) 

have developed an ecosystem management checklist for 

pinyon-juniper communities. 

Closing Thoughts 

Many of the decisions made on rangeland must be sitespecific, yet often site-specific information is not available. 

This is unfortunate because there are often treatments 

that have been applied in any given area, but no system was 

in place to evaluate the results and pass them along to 

future land managers. There is a need for ways of assembling fairly complex information into a simple format. One 

option is to use some form of the state-and-transition model 

initially proposed by Westoby and others (1989). This model 

is really a means of organizing information for use in 

management. Svejcar and Sheley (1995) suggested that 

state-and-transition models, and the primary causes of 

succession (site availability, species availability, and species 

performance), can be molded into a framework that 

would better integrate research and management. Stateand-transition models could be developed using ecological 

principles, research results, and local knowledge. The sitespecific monitoring data could then be used to evaluate 

and refine the state-and-transition models. Gaps in information would serve to prioritize research needs. 

Acknowledgments 

Drs. Lee Eddleman, Richard Miller, and Roger Sheley 

provided constructive comments. 

396 

References __________________ __ 

Aldon, E. F., R. Fletcher, and D. Shaw. 1994. A checklist for 

ecosystem management in southwestern pinyon-juniper. U.S. 

Department of Agriculture, Forest Service, General Technical 

Report RM-258:125-130. 

Angell, R. F. and R. F. Miller. 1994. Simulation ofleafconductance 

and transpiration in Juniperus occidentalis. For. Sci. 40:5-17. 

Barney, M. A. and N. C. Frischknecht. 1974. Vegetation changes 

following fire in the pinyon-juniper type of west-central Utah. J. 

Range Manage. 27:91-96. 

Barbour, M. G., J. H. Burk, and W. A. Pitts. 1980. Terrestrial plant 

ecology. The Benjamin/Cummings Publishing Company, Menlo 

Park, CA. 

Bates, J. D., R. F. Miller, and T. Svejcar. 1998. Understory dynamics 

in cut and uncut western juniper (Juniperus occidentalis ssp. 

occidentalis) woodlands. J. Range Manage. (submitted). 

Davis, J. N. and K. T. Harper. 1990. Weedy annuals and establishment of seeded species on a chained juniper-pinyon woodland in 

central Utah. In: Proceedings-Symposium on Cheatgrass Invasion, Shrub Die-off and Other Aspects of Shrub Biology and Management. USDA Forest Service Gen. Tech. Rep. INT-276:82-79. 

Erdman, J. A. 1970. Pinyon-juniper succession after natural fires 

on residual fires of Mesa Verde, Colorado. Brigham Young Univ. 

Sci. Bull. BioI. Series 11:1-24. 

Evans, R. A. and J. A. Young. 1985. Plant succession following 

control of western juniper (Juniperus occidentalis) with picloram. 

Weed Sci. 33:63-68. 

Everett, R. L. and D. F. Thran. 1992. Above-ground biomass in N, P 

and S capital in singleleaf pinyon woodlands. J. Environ. Manage. 34:137-147. 

Everett, R. L. and K. Ward. 1984. Early plant succession on pinyonjuniper controlled burns. NW Sci. 58:57-68. 

Koniak, S. 1985. Succession in pinyon-juniper woodlands following 

wildfire in the Great Basin. Great Basin Nat. 45:556-566. 

Quincey, S. D. 1984. Fire and grazing effects in western juniper 

woodlands of central Oregon. M.S. Thesis, University of 

Washington, Seattle. 

Sheley, R. L., T. J. Svejcar, and B. D. Maxwell. 1996. A theoretical 

framework for developing successional weed management 

strategies on rangeland. Weed Tech. 10:766-773. 

Svejcar, T. J. and R. L. Sheley. 1995. A conceptual framework 

for integrating natural resource management and research. 

Proceedings, Fifth International Rangeland Congress, Salt Lake 

City, Utah: 547-548. 

Westoby, M., B. Walker, and I. Noy-Meir. 1989. Opportunistic 

management for rangelands not at equilibrium. J. Range Manage. 42:266-274. 

Young, J. A., R. A. Evans, and C. Rimbey. 1985. Weed control and 

revegetation following western juniper (Juniperus occidentalis) 

control. Weed Science 33:513-517. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Factors Affecting the Health of Pinyon Pine 

Trees (Pinus edulis) in the Pinyon-Juniper 

Woodlands of Western Colorado 

Tom J. Eager 

Abstract-Mortality of pinyon pine has recently been on the 

increase throughout western Colorado. Black stain root disease 

(Leptographium wageneri) is a significant source of mortality for 

pinyon trees in infested stands. The pinyon ips (Ips confusus) is also 

an important factor in these stands. These mortality agents often 

act in concert, affecting large areas within the pinyon-juniper 

stands. Recent increases in human activity, most prominently road 

building and home construction, have increased the impact of the 

pathogen-insect complex. Efforts are underway to determine management activities which may reduce undesired mortality of pinyon 

pine trees. 

The pinyon-juniper forest type covers extensive areas of 

the southwestern United States. In the Four Corners Region 

over 14.9 million ha (37.2 million acres) are contained in this 

warm, lowland cover type. There is a total of 1.8 million ha 

(4.7 million acres) ofpinyon-juniper forest lands in Colorado, 

the majority of which are on the western slope of the 

Continental Divide, bordering the Red Rock region of the 

Colorado Plateau. 

The pinyon-juniper woodlands of Colorado have long been 

an important component of the forested landbase. In presettlement times, these areas served as the homelands of 

several indigenous native groups, the trees themselves providing fuel, materials for shelter, habitat for hunting and 

foraging in addition to supplying an important component of 

the diet, specifically pinyon nuts (seeds). 

Since the time of settlement, this forest type has been 

utilized in a variety of ways adding forage production and 

recreation to the list of uses. While the economic value of 

these lands has been regarded as being rather low in the 

past, increasing human populations and the development of 

an infrastructure able to sustain habitation of these harsh 

lands has increased the rate of development, particularly 

the construction of homes. 

This increase in the human population within the pinyon-juniper forest has been accompanied by an awareness 

that mortality of the pinyon pines is increasing at an 

unprecedented rate. Exclusion of disturbance events such 

as fire has caused a homogenization of stand characteristics, particularly age-class structure, and has resulted in 

forest stands which tend to be older and more advanced in 

the successional pathways of this cover type. The combined 

factors of increased human activity and an older, more 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Tom J. Eager is Entomologist, Forest Health Management, Rocky Mountain Region, U.S.D.A. Forest Service, Gunnison Service Center, 216 N. 

Colorado, Gunnison, CO 81230. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

successionally advanced condition are believed to be responsible for this increase in pinyon mortality. 

A number of different insects and diseases are specifically 

responsible for the increased mortality, the combined effects 

of these agents is being called pinyon pine decline. The 

actions of these various agents are being considered as a 

whole since the contribution of the various factors can vary 

greatly between sites. Additionally, these individual disturbance factors have not been studied well enough to separate 

their effects. There are a number of secondary insects and 

diseases affecting the health of pinyon pines, but the primary agents responsible for pinyon pine decline in Colorado 

appear to be black stain root disease (Leptographium 

wageneri) and pinyon ips (Ips confusus). 

Ips Bark Beetles (Ips confusus, 

Scolytidae:Coleoptera) ____ _ 

Bark beetles are well-known causes of damage and mortality in nearly all species of woody plants. The majority of 

bark beetles live and mine within the bark and wood of hosts, 

spending most oftheir lives within this cryptic environment. 

The genus Ips is a particularly prominent group of bark 

beetles due to their habit of attacking a number ofeconomically important timber species. Ips beetles are ranked high 

in terms of destructiveness to various species of pines and 

spruce. Most species of Ips have a restricted host range, for 

the most part they attack only a few closely related host 

trees. This is true of the pinyon ips, Ips confusus, which 

attacks both Pinus edulis and P. monophylla throughout 

their ranges. 

In general, pinyon ips act as a recycling and thinning 

agent in stands of pinyon pine. They attack and feed upon 

broken, fallen and dying trees, and are important factors in 

stand dynamics and nutrient pathways. However, when 

populations reach high levels in a given area, these beetles 

can be responsible for widespread mortality of otherwise 

heal thy trees. 

Pinyon ips are cylindrical beetles, 3.5 to 4.0 mm in length 

and are reddish-brown to black in coloration. A distinguishing feature of the Ips genus is the pronounced concavity at 

the rear end (declivity) of the elytra (wing covers) of the 

adult, which is margined on each side with 3 to six toothlike 

spines. Ips confusus can be recognized by the pattern of 5 

spines on each side of the elytra margins. 

Pinyon ips become active as temperatures warm up in the 

spring, beetle flight occurs on warm, sunny afternoo~s. 

Adult males leave overwintering sites and fly to potentIal 

hosts to initiate attack. The male beetles begin chewing an 

entrance hole in the host tree and this activity produces the 

signs of bark beetle attack, boring dust and pitch. The 

production of pitch is the host tree's way of defending itself. 

397 
If a host tree is to avoid colonization by the beetles, it must 

have an ample supply of pitch with which to entrap and force 

the beetles out of their attack sites. In turn, ips beetles must 

overcome the defenses of potential hosts if they are going to 

successfully produce brood. The attacking beetles coordinate their attacks on potential hosts by producing pheromones which concentrate large numbers of beetles on a 

specific host tree. Pheromone production by the initial beetles 

attracts additional males as well as females which assist in 

the attacks. This phenomenon of "mass attack" concentrates 

enough beetles to overcome the tree's defenses. 

The attacking beetles are assisted in their efforts to 

overcome the host's defenses by means of a symbiotic fungus, 

Ceratocystis sp. The adult beetles have small structures on 

their bodies in which they carry these fungal spores, and as 

the attack proceeds, these spores are released beneath the 

bark. The spores germinate, and the fungal mycelium begins 

to grow into the sapwood of the host tree, cutting off the host 

tree's vascular system and girdling it. The growth of this 

fungus is responsible for the characteristic blue staining in 

the wood of a tree attacked by bark beetles. 

As increasing numbers of beetles arrive at the host, the 

males are able to establish small chambers beneath the 

host's bark. Ips confusus is a polygamous species and three 

females usually respond to each male. After mating, each 

female begins to construct an elongate gallery which extends 

away from the central male chamber. The construction of 

these galleries prod uces another characteristic sign of beetle 

activity, the gallery pattern. In the case ofthe pinyon ips, the 

gallery pattern takes the form of an inverted "Y", with the 

mating chamber at the center ofthe three "arms" which each 

female has constructed. Each female then lays between 25 to 

40 eggs in small niches along these galleries. The eggs hatch 

in about a week and the larvae begin tunneling beneath the 

bark, feeding upon the host phloem. After several molts 

beneath the bark, the larvae form a pupal chamber and 

undergo the final metamorphosis to the adult stage. Adults 

remain beneath the bark for a short time and then emerge 

to attack new host trees. There can be from 2 to 5 generations 

per year, depending upon the elevation and climate. As 

temperatures cool in the autumn, beetles seek out overwintering sites in the dufflayer or beneath the bark of host trees. 

Black Stain Root Disease 

(Leptographium wagenerl) __ _ 

Black stain is the common name of a fungus which ca uses 

a vascular wilt of coniferous trees. While other strains of 

this fungus which cause black stain in Douglas-fir and 

ponderosa pine in the far West are relatively well-understood, black stain root disease in pinyon has not been 

in tensively studied. Black stain root disease was first noted 

in 1942 in Mesa Verde National Park. James Mielke began 

investigating the cause of pinyon pine mortality which had 

previously been ascribed to bark beetles. Mielke's work 

determined that bark beetle activity was secondary to black 

stain root disease as a cause of mortality. This work also 

noted the spread of the disease via root to root contacts 

(Wagener and Mielke 1961). 

Symptoms of black stain root disease are usually first 

manifested in the foliage of the host tree crown. Infected tree 

398 

needles become shorter and chlorotic and terminal growth is 

reduced. These general conditions become increasingly acute 

until the death of the host tree ensues in a relatively short 

period of time (as little as 2 to 3 years following initial 

infection). In addition, the disease predisposes the infected 

tree to attack by other damaging agents. Once a host has 

died, the fungus does not survive long and pinyon seedlings 

often reestablish in old black stain centers. 

Black stain can be identified by its distinctive coloration 

as well as the pattern and location of the staining. As the 

fungus spreads through the vascular system of an infected 

tree, it leaves a characteristic black to chocolate-brown stain 

or streaks of stain in the sapwood of the roots and/or root 

crown. Removal of bark in the area of the root crown and 

roots should reveal the characteristic coloration in infested 

trees. A second key characteristic is the pattern of the 

staining. Black stain appears in arc-like patterns in the 

sapwood of infested material when viewed in cross-section. 

This signature is in contrast to the pattern left by the bark 

beetle fungal symbiont, Ceratocystis sp. Blue stain appears 

as wedge shaped markings, in addition, the silvery-blue 

coloration appears throughout the length of the bole. 

Trees killed by black stain generally occur in groups or 

"centers". This pattern of mortality is a result of the local 

spread of the disease by root to root contact. Once established in a new root, the fungus colonizes the distal portions 

of the root and then grows towards the root crown. After 

infecting the root crown the fungus spreads throughout the 

remaining uninfected roots. 

Long distance spread of black stain, resulting in the 

establishment of new centers has also been observed. In the 

case of Douglas-fir and ponderosa pine black stain, insect 

vectors, particularly root-feeding weevils, have been shown 

to vector the disease. However, in the case of pinyon pine, 

insect vectoring has not yet been proven. Like their 

"cousins", the bark beetles, wood-feeding weevils are attracted to wounded and damaged host tissues. Their attraction to injured plant tissue makes them a favorable vector 

for the disease. 

Diagnosis of a black stain infestation center can be difficult, the symptoms may be obvious for only a short period of 

time. After the death of an infected host, the fungus survives 

only a relatively short period oftime. A number of trees may 

need to be examined before positive identification of the 

disease can be made, usually those trees which have very 

recently or soon will be dead provide the best possibility for 

detection. 

Pinyon Decline 

Forest management groups from throughout the Four 

Corners region have noticed an increase in the reporting of 

pinyon pine mortality over the last several years. While 

some of this mortality is being reported for the first time due 

to lack of previous monitoring, it is evident that actual 

mortality has increased significantly. This mortality is caused 

by a number of different agents in different locales, but the 

majority of the cases involve pinyon ips and black stain root 

disease. These organisms frequently act in concert, causing 

widespread areas of mortality. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
The bark beetles appear more as opportunists, taking 

advantage and colonizing trees weakened by black stain root 

disease or other disturbance factors. When a sufficient 

supply of susceptible host trees are available, numbers of 

beetles can reach fantastic levels, and the population can 

swell out to attack many otherwise healthy trees. An outbreak will decline over time, but often not before a large area 

has been affected and many trees have been killed. 

Black stain can be a major source of mortality in pinyon 

pine, but local spread ofthe disease occurs at a limited pace. 

In contrast, long distance spread of the disease can cause 

widespread mortality over large areas. The spread of the 

disease appears to be exacerbated by the activities of wood 

or root feeding insects. These insects are attracted by 

wounded or damaged host tissues and can compound other 

forms of stand disturbance. 

Both the insect and the fungus are encouraged by stand 

disturbance. Trees under stress serve as a food source for 

bark beetles. The spread of black stain may be accelerated by 

the activities of vectors which thrive on damaged or stressed 

host trees. 

The rapid increase of human activity in the pinyonjuniper woodlands of western Colorado has in some cases 

created conditions favorable to black stain and pinyon ips. 

Direct wounding of trees, damage to root systems, and 

improper treatment of cut trees and slash has created a large 

source of potential host material. House, road and utility 

line construction frequently damage pinyon pines and allow 

the rapid increase of mortality agents. Since many of these 

trees are valuable as landscape plants, the death of even a 

few is undesirable. On a landscape scale, dead trees may 

increase fuel loads and pose a threat due to wildfire. Outbreaks of these mortality agents also interfere with other 

management objectives. The relatively slow growth ofvegetation associated with the pinyon-juniper woodland further increases the impact of widespread mortality. 

Conclusions --------~-----------------------

The best prospects for reducing the impacts of pinyon 

decline is by maintaining the forest in as vigorous a condition as possible. Variability of stand conditions within a 

forest reduces the risk of widespread mortality due to one 

or two factors. Sanitation of stands by prompt removal of 

damaged host material reduces a potential source of food 

for damaging agents. Over the long run, reintroduction of 

USDA Forest Service Proceedings RMRS-P-9. 1999 

prescribed fire will reduce biomass and fuel loads. In other 

areas, thinning and harvesting can help achieve desired 

stocking levels and stand conditions. 

Two simple tactics that individual land managers can 

utilize are proper slash management and timing of activities. Removal or treatment (burning, burying, debarking, or 

tarping can be used under various circumstances) of pot ential host material (including stumps, logs, and large branches) 

can reduce the potential for increased mortality due to bark 

beetles. Scheduling potentially disruptive activities in pinyon -juniper stands during the cooler winter months can also 

reduce the risk of mortality. Activities should be as nondisruptive as possible, but working in cooler weather (roughly 

late November to early March in western Colorado) while 

the insects are inactive will allow time for managers to 

sanitize the stands following activity. In addition, timing of 

activities during the winter months allows the trees to 

"recuperate" a bit before the bark beetles and weevils become active in the spring. 

There are many gaps in the information base regarding 

pinyon pine decline. As the value ofthese lands continues to 

escalate these questions will become increasingly important. Information on the stand factors which increase susceptibility to pinyon decline and the longevity of the influence ofblack stain within infested areas will be necessary for 

effective long-term management of these stands. The role 

and identity of vectors of black stain, and the influence of 

secondary organisms such as other insects, fungi and nematodes also needs investigation. 

Public information will be an important part of any effort 

to reduce pinyon mortality. A better understanding of the 

natural environment under which these trees evolved is 

necessary. Many trees are literally "killed with kindness": 

drowned by water, overfertilized, or paved around. Others 

are strung with fences and wires, cut and trimmed indiscriminately, or otherwise mistreated. Managers need to 

consider the trees under their care as part of a larger 

woodland. They need to work beyond their property lines 

and consider pinyon-juniper stands as a crucial component 

of the landscape. 

Reference __________ _ 

Wagener, w. W.; and J. L. Mielke. 1961. A staining-fungus root 

disease of ponderosa, Jefferey and pinyon pines. Plant Disease 

Reporter. 45 (11) : 831-835. 

399 
The Budgetary, Ecological, and Managerial 

Impacts of Pinyon-Juniper and Cheatgrass 

Fires 

Thomas C. Roberts, Jr. 

Ahstract-The 1996 fire season illustrated the potential impacts of 

wildland fires on the Bureau of Land Management (BLM) administered lands through numerous western states. During the 1996 fire 

season, over six million acres burned in the United States through 

unplanned ignitions (wildfires). Over two million acres burned on 

BLM administered acreage, with over three hundred thousand of 

them having Emergency Fire Rehabilitation (EFR) projects implemented on them with project costs of over $21 million, over a three 

year period. Many of these fires were on lands dominated by pinyonjuniper or cheatgrass vegetation community types. These fires are 

~ndicative of fuel loads and fire conditions that lend themselves to 

unplanned or planned ignition and commensurate ecological implications. Pinyon-juniper and cheatgrass fires, as often happen on 

BLM managed lands are expensive to rehabilitate, disruptive to the 

workforce and local land users, and at times contentious in methods 

used for rehabilitation. This paper will describe the budgetary, 

ecological, and managerial implications of these wildland fires and 

their rehabilitation within the BLM, using the 1996 fire season as 

an example. 

The Bureau of Land Management (BLM) administers 

approximately 270 million acres of public land, with about 

170 million in the lower forty eight states. Wildfire is a 

planned and budgeted program, with a programmed budget 

and workforce, that although in the most part seasonal, is 

obligated in its tasks, training. and commitment. As performed in the BLM, Emergency Fire Rehabilitation (EFR) is 

funded under the Fire Operation and Suppression Accounts, 

and performed on an as needed basis. As such, training and 

support, until recently have been a low priority, with very 

few full time personnel and limited training. However, 

during the 1996 fire season, over six million acres burned 

across the country, including over two million on BLM 

administered lands, rehabilitation projects were implemented on over three hundred thousand acres with costs of 

over $21 million, spread over a three year period. The states 

of Idaho and Utah were particularly heavily hit with large 

expensive fires in each state. The fires caused millions of 

dollars of un budgeted expenditures to be planned, requested 

and budgeted. Utah alone needed almost $9,000,000, with 

Idaho, Nevada and Oregon also needing significant amounts 

of funding. These amounts significantly exceeded the 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Thomas C. Roberts, Jr. is Emergency Fire Rehabilitation Program Lead, 

Washington Office, Bureau of Land Management. 

400 

usually budgeted amount of $5,400,000 necessitating the 

request for supplemental funding through the Department 

of Interior. While to some extent, an obligated budget like 

Social Security or Medicare, it is not without scrutiny or 

concern that such large increases are made by the BLM. 

Indeed there is and has been a large amount of discussion 

and concern about the appropriate level of rehabilitation or 

"restoration", or to some observers, reclamation, that needs 

to be done after a fire. These discussions well illustrate not 

only a person's fiscal philosophies, but their philosophies 

about the role of government in ecological matters. It is 

likely that as the 1996 and 1994 fire season are averaged 

with lower cost years, the average cost for the Emergency 

Fire Rehabilitation program will increase, and this is without anticipated increases in burned acreage, that may be in 

the future. 

The ecological impacts ofthe pinyon-juniper and cheatgrass 

fires are particularly significant in Idaho, Nevada, and 

Utah, which have had a considerable number of fires in the 

last twenty years. In an era when the "health" ofthe land is 

often a subject of discussion, the impacts of these fires and 

their results have the potential for omission, when their 

impacts have both positive and negative possibilities. The 

pinyon-juniper community type has in common with the 

invasive annual, cheatgrass, the fact that they affect both 

the sagebrush-grass and salt desert shrub types where 

elevation or precipitation patterns permit. As such they 

affect a number of states including California, Colorado, 

Idaho, New Mexico, Nevada, Oregon, Wyoming and Utah. 

The implications of the management of the pinyon-juniper 

type are changing in visibility and ecological importance 

because ofa number of reasons. The pinyon-juniper community type covers a large area, a diversity of uses and values, 

and the results of management decisions will be noticed 

whether those decisions are by intent or default. Fire and 

fire rehabilitation have a particularly large role in the 

management ofthis ecotype. Concurrently, this administration is encouraging the use of fire or the reinstatement of fire 

into ecosystems where it has been absent. 

There are a number of considerations that are necessary 

to avoid ecological problems in the reinstatement of fire, 

including the presence of cheatgrass or other invasive plants 

on a site to be burned or one that has burned, and the lack 

or presence of a desirable understory prior to the fire. There 

are many areas dominated by pinyon-juniper or becoming 

dominated by them that may need appropriately applied fire 

or lack of aggressive suppression, should a wildfire start, but 

unless they have a desirable understory, either a funding 

source is necessary to reseed with desirable plant species or 

prescribed fire postponed until a funding source located, or 

in the case of wildfire, Emergency Fire Rehabilitation funds 

USDA Forest Service Proceedings RMRS-P-9. 1999 
may be appropriately used to fund a rehabilitation project. 

Basically, fire rehabilitation funded with EFR funds may be 

done to reduce soil erosion, protect private property and life, 

and to deny the entry or expansion of weeds. It is not meant 

to be a restoration account, although possibly desirable, site 

restoration is not the primary goal of the EFR program. 

However, as stated above, fire and fire rehabilitation can 

be powerful tools in land management in the BLM. There are 

presently about 45,000,000 acres dominated by pinyonjuniper trees under administration ofthe BLM (USDI, 1993) 

and an estimated 75,000,000 acres with cheatgrass or with 

the potential for the presence of cheatgrass (Pellant and 

Hall, 1994). The ecological problems related to these fires 

have been documented by many including, Bunting, (1994), 

Billings, (1994), and others. Bunting (1994), found that the 

fire free interval of juniper dominated areas to be as long as 

fifty years and suggests a number of scenarios to explain the 

present situation, and ecological impacts of fire in the 

juniper type in the Great Basin. Indeed, the apparent conflicting needs of ecosystems dominated by juniper or pinyon 

andjuniper, and the necessity to control fire in sagebrush or 

shadscale ecosystems that are at risk because of the presence of cheatgrass have been documented by Pellant (1994), 

Roberts (1994), and others. Probably most telling is Billings 

(1994) where he states that "Cheatgrass in the Great Basin 

area has become abundant enough to provide fuel for disastrous and extensive fires". Roberts (1994) reported on the 

resource impacts of a ten year history offire in the Salt Lake 

District of the BLM, consuming nearly 500,000 acres of 

rangeland documenting differences between sites before 

and after fires and the impacts due to the presence of 

cheatgrass. Whisenant (1990) reported on the decreased fire 

frequencies in the Snake River Plains ofIdaho, again due to 

the presence of cheatgrass. As illustrated above, the ecological implications related to fire and the pinyon-juniper community type are integral to questions related to the presence 

or absence of cheatgrass. 

The managerial challenges are final and possibly the most 

limiting to these intertwined ecosystems. Again, using Utah 

as an example, the fires of 1996 caused an expenditure of 

over425 workmonths in rehabilitation projects on the burned 

over acreage, much of it juniper or cheatgrass dominated. 

Although half of those workmonths were accomplished by 

temporary labor, the other halfwas work done by full time 

permanent employees, including range conservationists, 

wildlife specialists, botanists, engineers, equipment operators, archaeologists, surveyors, public affairs officers, and 

numerous others. Unfortunately, the use of solicitors and 

even the BLM's Resource Advisory Council because of the 

use of chaining, a controversial method of burying seed 

(in Utah), was necessitated because onegal challenges and 

ultimately a Temporary Restraining Order prohibiting the 

Utah BLM from completing one project. Idaho also had 

difficult questions relating to fires near Boise. The Eighth 

Street Fire, just inside Boise City limits was human caused, 

burning up through dry cheatgrass and shrub vegetation 

though publicly and privately owned land to be stopped on 

the Boise National Forest. The choice of rehabilitation techniques, in this case terracing, caused a furor in Boise, which 

threatened to shut down the project. Ultimately, it is probable that result was less than first proposed, but more than 

desired by many. It was a fire and rehabilitation project that 

USDA Forest Service Proceedings RMRS-P-9. 1999 

will be monitored for a number of years. It also had significant impacts on the workforces of Boise District (BLM) and 

Boise National Forest, while drawing upon the concerned 

volunteers of Boise City. While costing millions of dollars as 

did the projects did in Utah, it involved much less land, and 

many more people and more jurisdictions, including the 

BLM, U.s. Forest Service, state and county governments, 

and private land owners. 

In conclusion, the problems or challenges caused by pinyon-juniper vegetation and fires, and cheatgrass are many 

and will continue. The dilemma caused by fire exclusion and 

the concomitant increase injuniper dominated land is countered by the cheatgrass presence and its problems. Apotential problem that may make cheatgrass look benign are the 

secondary invasive weeds such as medusahead-rye, yellow 

starthistle, diffuse knapweed, and rush skeleton weed, weeds 

that have been found on the Eighth Street fire, and some of 

the Utah fires. These are weeds, particularly yellow 

starthistle and diffuse knapweed, that have little or no 

forage producing capacity, have the same site dominating 

capabilities of cheatgrass, and sharp thorns that destroy the 

site's recreational desirability also. The 1997 fire year was a 

light to moderate fire year, with adequate moisture for a 

high fuel buildup and carryover into next season, indicating 

that 1998 could be as difficult or worse than 1996. 

In a positive note, the BLM and Forest Service have 

increased their training and in the BLM's case revised its 

EFR Handbook to reflect a broader approach to fire rehabilitation. There has also been a great amount of discussion and 

evaluation of Post-Fire rehabilitation policies and directions, being done at the Departmental Level, at the Department ofInterior. It is likely that this review will examine the 

policies and funding authorities being used by Interior 

agencies, and BLM in particular. 

This review may also have some impacts on the Forest 

Service. In the short run, the agencies are committed to an 

increased level of communication and coordination on training, and when necessary, project planning and implementation. It can be expected, however, that continuing discussions or concerns will remain as to funding authorities and 

philosophies for fire rehabilitation, and how far that approach can be extended towards vegetation restoration on 

the burned site. It should be anticipated, however, that as 

discussed above, there will likely plenty of rhetorical and 

physical fuel to continue some of the controversies relating 

to management of the pinyon-juniper ecosystem and its 

adjacent ecosystems, particularly as the discussions relative 

to ecosystem "health" continue. 

References _________ _ 

Billings, W.D. 1994. Ecological Impacts of Cheatgrass and Resultant Fire on Ecosystems in the Western Great Basin. In: Monson, 

Stephen B. and Kitchen, Stanley G., comps. Proceedings-Ecology and Management of Annual Rangelands; General Technical 

Report INT-GTR-313. USDA Forest Service, Intermountain Research Station, Ogden, Utah: 22- 31. 

Bunting, S.D. 1994. Effects of Fire on Juniper Woodland Ecosystems in the Great Basin. In: Monson, Stephen B. and Kitchen, 

Stanley G., comps. Proceedings-Ecology and Management of 

Annual Rangelands; General Technical Report INT-GTR-313, 

USDA Forest Service, Intermountain Research Station, Ogden, 

Utah: 53-56. 

401 
Pellant, M, and Hall, C. 1994. Distribution of Two Exotic Grasses on 

Intermountain Rangelands: Status in 1992. In: Monson, Stephen 

B. and Kitchen, Stanley G., comps. Proceedings-Ecology and 

Management of Annual Rangelands; General Technical Report 

INT-GTR-313. USDA Forest Service, Intermountain Research 

Station, Ogden, Utah: 109-113. 

Roberts, T.C., Jr. 1994. Resource Impacts of Cheat grass and Wildfires on Public Lands and Livestock Grazing. In: Monson, Stephen 

B. and Kitchen, Stanley G. comps. Proceedings-Ecology and 

Management of Annual Rangelands; General Technical Report 

INT-GTR-313. USDA Forest Service, Intermountain Research 

Station, Ogden, Utah: 167-170. 

402 

USDI, Bureau of Land Management, 1993. Forests: Our Growing 

Legacy, Bureau of Land Management, Washington, DC, 20240. 

Whisenant, S.G. 1994. Changing Fire Frequencies on Idaho's Snake 

River Plains: Ecological and Managerial Implications; In: 

McArthur, E.D.; Romney, E.M.; Smith, S.D.; Tueller, P.T., comps. 

Proceedings-Symposium on Cheatgrass Invasion, Shrub Die-off 

and Other Aspects of Shrub Biology and Management; General 

Technical Report INT-GTR-276. Ogden, Utah, USDA Forest 

Service, Intermountain Station: 4-11. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Control of Weeds at a Pinyon-Juniper Site 

by Seeding Grasses 

Sherel Goodrich 

Dustin Rooks 

Abstract - An area seeded to perennial grasses and an adjacent 

nonseeded area both within a burned Colorado pinyon/Utahjuniper 

(Pinus edulis Engelm./Juniperus osteosperma [Torr.] Little) community provided an opportunity to contrast frequency of plant 

species in the two treatments. Lower frequencies for cheatgrass 

(Bromus tectorum L.) and yellow salsify (Tragopogon dubius Scop.), 

which are introduced annuals, were found in the seeded area. 

Abundance of musk thistle (Carduus nutans L.), a noxious weed in 

Utah, was found at much reduced density and frequency where the 

burn had been seeded compared to where the burn had not been 

seeded. Higher frequency for squirreltail (Elymus elymoides [Raf.l 

Swezey), which is a native perennial grass, was found in the seeded 

area compared to the nonseeded area. Management implications 

include the need for advanced collection and storage of seed to 

supply the need for seeding large burns to prevent dominance of 

cheatgrass and other invasive weeds in these burns. 

Introduced weedy plants present a formidable challenge 

to the management of native plant communities. Indeed 

cheatgrass (Bromus tectorum 1.) seriously challenges the 

concept of maintaining native plant communities in some 

areas such as on the Snake River Plain and valleys and 

foothills of the Great Basin. Once established it is perpetuated by high fire frequencies by which it is able to exclude 

sagebrush and other native species (Peters and Bunting 

1994). Some other introduced plants are also highly competitive including those on noxious weed lists of various states 

such as musk thistle (Carduus nutans L.). Control of these 

species has become a major concern where they now dominate thousands of acres and result in great economic loss 

(Leistritz and others 1996; Whitson and others 1991). 

While some of these species are competitive at higher 

elevations in aspen and spruce-fir belts, cheatgrass is generally not. However, the thermal belt of Colorado pinyon 

(Pinus edulis Engelm.) and Utah juniper (Juniperus 

osteosperma [Torr.] Little) is prime habitat for cheatgrass. 

Coupled with the nature of pinyon -juniper to greatly oppress 

native understory species and outlive the seed banks of 

these species (West and Van Pelt 1987), the explosive ability 

of cheatgrass to increase after disturbance (Young and 

In: Monsen) Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Sherel Goodrich is Forest Ecologist, Ashley National Forest, Forest Service, U.S. Department of Agriculture, Vernal, UT 84078. Dustin Rooks is a 

student of natural resources, Southern Utah University, Cedar City, UT 

84078. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Evans (1978) presents a scenario in which it is difficult to 

apply a concept of native plant communities. Disturbance is 

usually a matter of "when" more than of "if." When disturbance comes to mature and old stands of pinyon -j uni per they 

are left wide open to the invasion of cheatgrass and other 

invasive weeded species by the general lack of native understory species that is a function of pinyon-juniper stand 

closure (Everett 1987; West and Van Pelt 1987). 

With an expanding human population of increasing mobility, the spread of weeds can be expected to remain at high 

levels and probably increase. This scenario has and will 

continue to complicate the maintenance of native plant 

communities. Applying a concept of wilderness or natural 

areas where disturbance by humans is hopefully omitted, 

will not always adequately address this challenge. Some of 

these plants have shown ability to enter and increase on 

sites where disturbance by man is minimal. 

Kindschy (1994) reported the presence and increase of 

cheatgrass in southeastern Oregon's Jordan Crater Research Natural Area that has been protected from human 

activities including livestock grazing. Tausch and others 

(1994) found cheatgrass has displaced native perennial 

species on Anaho Island in Nevada despite a general absence 

of human-caused disturbance and fire. They attributed the 

increase to the competitive ability of cheat grass. Young and 

Tipton (1990) cited two works from southeastern Washington that documented observations of cheatgrass successfully 

inserting itself into climax perennial grass/shrub communities that had been protected from fire and grazing for as long 

as 50 years. They proposed the idea of cheat grass spreading 

in a biological vacuum created by grazing may be somewhat 

misleading or overstated. Goodrich and Gale (these proceedings) reported high frequency of cheat grass on two sites with 

little apparent use by non-Native Americans or their livestock that are wi thin 2.4 and 5.6 km (1. 5 and 3.5 miles) ofthis 

study site. Knight (1994) reported the cheatgrass problem is 

not restricted to land managed for livestock, and he gave an 

example of an increase of cheatgrass following fire in Little 

Bighorn Battlefield National Monument in southern Montana. He suggested that managing vegetation of a National 

Monument so it reflects presettlement conditions is a goal 

that may be impossible once certain introduced species 

become established. 

In addition to the ability of cheatgrass to invade some 

native plant communities wi thou t disturbance, the reality of 

the modern world includes international travel, high speed 

freeways, and a maze of other paved and dirt roads. Vehicles 

are a major means by which seeds are spread. Within a day, 

modern travel can carry seeds not only across major drainages but across oceans. It is common for seeds from vehicles 

to be deposited in disturbed areas where there is comparatively high probability for establishment. Northam and 

403 
Callihan (1994) examined five exotic annual grasses of 

recent introduction to the inland Pacific Northwest. Their 

work indicates the introduction of alien species continues 

and their dispersal has been enhanced by human transportation technology. The seeds of musk thistle and some other 

weedy species are highly adapted to transport by wind. This 

feature also indicates a continuing spread of these species. 

The ability of invasive weeds such as cheatgrass to spread 

and greatly alter ecosystem function indicates high priority 

for dealing with these species. 

Features and Recent History of the 

Study Location 

The study site is within the North Skull Creek Burn of 

1976, in the Green River corridor near Flaming Gorge in 

Daggett County, Utah, about 6 miles northwest of the town 

of Dutch John, within the Uinta Mountain Section as defined by McNab and Avers (1994). Annual precipitation at 

the Flaming Gorge Weather Station (near Dutch John) is 

31.75 cm or 12.50 inches (Ashcroft and others 1992). The 

study site is within a landtype composed of ridge and ravine 

topography underlain by Precambrian quartzitic materials 

and shales of the Uinta Mountain Group. Within the landtype 

there are two general phases. One phase is on northerly 

exposures where alder-leaf mountain -mahogany/bl uebunch 

wheatgrass (Cercocarpus montanus Raf.lElymus spicatus 

[Pursh] Gould) communities of high plant diversity are seral 

to pinyon and juniper. The other phase is on southerly 

exposures where communities of rubber rabbitbrush 

(Chrysothamnus nauseosus [Pallas] Britt.), sagebrush (Artemisia L,) and grasses are seral to pinyon-juniper. On the 

southerly exposures cheatgrass has proven to be a highly 

competitive plant. It is less competitive on the northerly 

exposures. 

History of the site included livestock grazing up to about 

1972. Livestock grazing was not permitted at this study site 

from before the burn of 1976. Although livestock had grazed 

the area in earlier decades, age and crown closure of trees 

prior to burning indicate little forage production inside the 

stand prior to European settlement. Livestock would not 

have been highly attracted to the site due to distance to 

water as well as low forage production. A stock watering 

pond had been constructed near the site, but it rarely held 

water. 

The burn site is at 2,134 to 2,256 m (7,000 to 7,400 ft) 

elevation on a southerly exposure with gradients of 10 to 50 

percent. The study site within the burn is on gradients of 10 

to 20 percent. The burn was not seeded following the 1976 

fire. The decision not to seed reflects the attitude that 

without livestock, native plants would occupy the site after 

burning. However, occupation of dense stands of pinyon and 

juniper had exceeded the life span of seed banks for most 

species. Response of native plants was low. Within a decade 

cheatgrass dominated the site. Other introduced plants 

became abundant including musk thistle, which is included 

on noxious weed lists for several Western States. The aggressive nature of this plant allows it to spread rapidly 

forming extremely dense stands that crowd out other species 

(Whitson and others 1991). 

404 

The site was serving as a source of weed seed to spread to 

other areas. It was prescribed burned again on June 27, 

1990, when cheatgrass seed was mature but had not yet 

shattered. The prescription was intended to reduce cheatgrass 

long enough to facilitate establishment of seeded species. 

The burn was aerial seeded in fall 1990 with a mixture of 

grasses and forbs. However, parts of the burn were missed 

in the seeding, which allowed a comparison of adjacent 

seeded and unseeded areas. The seed mix included aggressive, introduced grasses such as crested wheatgrass 

(Agropyon cristatum [L.] Gaertner), intermediate wheatgrass (Elymus hispidus [Opiz] Meld.), orchardgrass (Dactylis 

glomerata L.), and smooth brome (Bromus inermis Leysser). 

Methods 

Six growing seasons after the 1990 burn and seeding, five 

30.5 m (100 ft) belt lines were established in each of the 

seeded and nonseeded areas ofthe burn along which samples 

were taken in 100 frequency plots. Rooted nested frequency 

for all species present was determined in each offour nested 

plot sizes at each of the 100 plots as outlined by u.S. 

Department of Agriculture, Forest Service (1993). The method 

allowed for a score of 400 for each species. Scores for the more 

frequent species are shown in table 1. Also the number of 

musk thistle plants were recorded in 0.91 by 30.5 m (3 by 100 

ft) macro plots along each of the belt lines for a total sample 

area of 0.0139 ha (0.0344 acres). 

Results __________ _ 

There were 26 and 270 musk thistle plants in the five 

macro plots for the seeded and nonseeded areas, respectively, or 1,871 and 19,424 plants per ha (756 and 7,849 per 

acre) in the seeded and non seeded areas, respectively. Six 

growing seasons postseeding, the nonseeded area supported 

10 times more musk thistle plants than did the seeded area. 

Nested frequency scores were significantly higher in the 

nonseeded area than in the seeded area for cheatgrass, musk 

thistle, yellow salsify (Tragopogon dubius Scop.), and Canada 

Table 1-Nested frequency scores for eight species. Based on a 

potential score of 400 

Plant species Seeded area Nonseeded area 

Cheatgrass 309 347 

Musk thistle 6 44 

Yellow salsify 66 126 

Canada thistle 0 28 

Squirreltaila 178 133 

Crested wheatgrassa 75 5 

Intermediate wheatgrassa 66 3 

Orchard grassa 76 6 

Smooth bromea 49 0 

Other annuals and biennials 1 26 

Other herbaceous perennialsa 97 79 

8Herbaceous perennial species excluding Canada thistle. 

For all species of this table, the spread in scores between the twp areas is 

indicated to be significant at 80 percent probability (Chi Square = 1.642 with 1 

degree of freedom). 

USDA Forest Service Proceedings RMRS-P-9. 1999 
thistle (Cirsium aruense [L.] Scop.). Scores were higher in 

the seeded area for squirrel tail (Elymus elymoides [Raf.] 

Swezey) and for crested wheatgrass, intermediate wheatgrass, orchardgrass, and smooth brome (table 1). 

Discussion __________ _ 

Reduced frequency of weedy species was found in the 

seeded area. With the exception of Canada thistle, perennial, herbaceous species had higher frequency scores in the 

seeded area. The seeded and nonseeded sites were adjacent 

to each other and conditions were very similar at each site. 

However, some species could have been more abundant at 

one site than the other prior to treatment. This is most likely 

for squirreltail and Canada thistle. The invasive nature of 

cheatgrass indicates it had near equal frequency across the 

two sites prior to treatment. Musk thistle and yellow salsify 

are annual or biennial weeds with highly mobile seeds. The 

high mobility of the seeds and annual or biennial habit of 

these plants indicate these two species can be expected to 

have equal distribution in the seeded and nonseeded areas. 

Although Canada thistle has highly mobile seeds, there 

seems to have been little recruitment of this perennial 

species by seed since the second burn. Persistence and 

advance ofthis species is expected to be largely a function of 

its robust rhizomes. This plant is expected to have been most 

common in the unseeded area prior to seeding. The difference in scores for this species is not expected to be a function 

of seeding. 

Much of the reduction of the introduced annual and 

biennial plants including cheatgrass appears to have been a 

function of seeding perennial grasses. The difference in 

nested frequency scores for cheatgrass between the seeded 

and unseeded areas might appear too small for an obvious 

shift in dominance of this species to a greatly reduced 

position in the community. However, comparison ofthe total 

scores for perennial herbaceous species between the two 

areas indicates the wide difference in the communities. 

Total scores for perennial herbaceous species excluding 

Canada thistle were 541 for the seeded area and 226 for the 

unseeded area. Difference in cheatgrass between the seeded 

and unseeded sites goes beyond frequency. Size of cheat grass 

plants was also reduced in the seeded area. Davis and 

Harper (1990) also reported reduction of weedy plants concurrent with establishment and increase of seeded species at 

a juniper-pinyon site in central Utah. 

Management Implications 

The explosively invading, highly competitive nature of 

cheatgrass (Pyke and Novak 1994; Harris 1967; Hironaka 

1994; Nasri and Doescher 1995a,b; Young and Evans 1978; 

Evans and Young 1978) and especially on southerly exposures (Monsen 1994) might have been expected prior to the 

1976 b~rn at North Skull Creek. However, much of the 

literature dealing with the competitive ability of this plant 

has come since that time. The decision not to seed following 

the 1976 fire seems to reflect the perception ofthat time that 

the native flora would dominate the site in the absence of 

livestock. However, the ability of cheatgrass to drive community dynamics goes beyond the influence of livestock 

USDA Forest Service Proceedings RMRS-P-9. 1999 

grazing as discussed at the first of this paper. On some sites, 

it is a better competitor for soil moisture than are some 

widespread, highly successful native, perennial grasses including bluebunch wheatgrass (Harris 1967; Hironaka 1994; 

Pyke and Novak 1994) and Idaho fescue (Festuca ouina var. 

ingrata Hackel ex BeaD (Nasri and Doescher 1995b). 

The ability of cheatgrass to drive plant community dynamics on pinyon-juniper sites as well as sagebrush sites 

presents a formidable challenge to maintenance of native 

plant communities. It is becoming increasing apparent that 

in some places plant communities will not be as they were 

before the advent of cheatgrass and other Eurasian introductions. South-facing slopes of pinyon-juniper ecosystems 

are one of these places. Super dominance (West and Van Pel t 

1987) that comes with long-term occupation of pinyonjuniper trees of high percent crown closure leaves a depauperate understory that is essentially unable to respond after 

fire with the rapidity needed to compete with cheatgrass. 

Closed stands of pinyon andjuniper are often quite effective 

in keeping cheatgrass at low levels. However, cheatgrass 

has inserted itself into these stands and has become wide 

spread in the pinyon-juniper ecosystem. Young and Evans 

(1978) found density of cheatgrass plants increased from 101 

m2 the first year after fire to 10,000/m2 bythethirdyear. Fire 

in dense stands ofpinyon-juniper sets the stage for this kind 

of cheatgrass response. Fire in woodlands is more often a 

matter of "when" than "if." Eventually, many stands burn 

and are then exposed to cheatgrass and other weedy, introduced species. 

Response to this situation includes doing nothing in 

which case, dominance of cheatgrass is strongly indicated 

by its past performance. Seeding can greatly decrease t~e 

influence of cheatgrass, but this is not likely to exclude It. 

Currently some of the most competitive plant materials for 

which seed is available in quantities sufficient to respond to 

large fires are of Eurasian origin. In recent years seeding 

these species has become increasingly objectionable because of their origin. However, this presents a dilemma of 

"choose your alien." The choices are a dominance of the 

annual cheatgrass or a mixture of perennial species of 

which some of the most likely to compete with cheatgrass 

are of Eurasian origin. 

This dilemma points to the urgent need to develop native 

plant materials that are more competitive with cheatgrass. 

Until such materials are developed and of sufficient quantity to respond to large fires, introduced species such as those 

used in the 1976 North Skull Creek Burn seem to provide an 

alternative to cheatgrass. For 1996, Roberts (these proceedings) reported over 6 million acres burned in the. U,nited 

States through unplanned ignitions with over 2 mIllIon of 

these acres on lands administered by the Bureau of Land 

Management where over 300,000 acres were included in 

Emergency Fire Rehabilitation projects. Many of these fires 

were on lands dominated by pinyon-juniper and cheatgrass 

communities. Over 200,000 acres of pinyon-junipercheatgrass range burned in central Utah in 1996. The scale 

of these projects went far beyond availability of seed of 

native species. 

The concept of using seed of local, native plants only to 

preserve pure local ecotypes without con~~mi~ating :heir 

gene pools has become an issue for rehabIlItatIOn proJects. 

This concept might be practical for small projects and espe405 
cially outside the ecological range of cheatgrass and other 

highly aggressive, invasive species. However, the scale of 

fires of 1996 demonstrates the futility of demanding seed of 

local natives only for use in seeding large burns. The ability 

of cheatgrass to increase from 10 to 10,000 plants per square 

m from the first to the third year postfire (Young and Evans 

1978) demonstrates the need to apply seed in the year of the 

burn. This requires advanced storage of seed for rehabilitation projects. The critical need for advanced storage and 

early application of seed will be difficult to supply under a 

concept of "on site" collected seed of "pure" local natives. This 

concept is plagued by the uncertainty of specific sites of 

future fires. It is also difficult to apply after locations of fires 

are known. After fire, it is too late to collect abundant seed 

from the specific site. The year in which a fire burns can be 

a poor year for seed in areas adjacent to a burn. 

Cheatgrass and other aggressive introduced weedy plants 

seriously challenge the concept of maintaining some native 

plant communities including many within the pinyon-juniper belt. Responding to these weedy plants might require 

looking beyond our traditional fascination with native plant 

communities, and especially if that fascination is based on a 

concept of "pure native" where "pure" implies native communities oflocal gene pools without influence of outside forces. 

American isolation from the Old World, ifit ever existed, 

stopped in 1492. The incidence of introductions and distribution of plants as a function of travel and Eurasian occupation 

has increased greatly since than time. Some ofthe introductions are simply better competitors in some environments 

than are natives. Or at least these introductions are aggressive enough to insert themselves into and maintain themselves in native plant communities that then are no longer 

native in a pure sense. Knight (1994) has suggested that 

management of vegetation so it reflects pre-European settlement conditions is a goal that may be impossible once certain 

species become established. His suggestion combined with 

the catastrophic and large-scale change induced by cheatgrass 

and other weedy species in the Great Basin (Billings 1994) 

and Snake River Plain (Peters' and Bunting 1994) vividly 

portray the potent ecological force of cheatgrass. 

Standards for plant communities within the pinyon-juniper belt based only on natives and especially only local 

natives could reflect more romanticism than realism. We 

agree with Young's (1994) evaluation that: "The inherent 

variability in bluebunch wheatgrass and related native 

species is a vital part of the cheatgrass range restoration 

picture. If the genotypes cannot be found in bluebunch 

wheatgrasspopulations, which can compete with cheatgrass, 

then range restoration is dependent on: (1) reestablishment 

of high-technology weed control systems, (2) hybridization of 

bluebunch wheatgrass with relatives such as quackgrass (A. 

repens ) [Agropyron repens L.] that are not native, followed 

by selection for competitive ecotypes, or (3) accept exotic 

hybrids that are competitive." 

At the North Skull Creek Burn, native plants, in the 

absence of livestock, did not prevent cheatgrass dominance 

or an abundance of musk thistle. The seeding at the North 

Skull Creek Burn demonstrates the ability of crested wheatgrass and other introduced perennial grasses to reduce 

cheatgrass and musk thistle to subordinate positions in 

plant communities. These highly successful plant materials 

are the product of hundreds of years of selective breeding for 

406 

high seed production, ease of harvest , vigorous germination, 

rapid establishment, high production, and other features. 

Establishment of these species and reduction of cheat grass 

indicates a reduced fire frequency that can facilitate increased of sagebrush and other native species including 

pinyon and juniper. Fire frequency typical of cheatgrass 

dominated lands is commonly too high to allow for the return 

of native woody species. 

In response to fires of 1996, many thousands of pounds of 

seed of introduced species were used not because managers 

prefer them over natives, but because seed of suitable 

natives was not available. It is not the intent of this paper 

to recommend continued use of introduced species for 

seedings. However, until large quantities of seed of native 

species with the ability to compete with and suppress 

cheatgrass are available, the introduced species seeded at 

North Skull Creek Burn provide an alternative to cheatgrass 

dominance. This and the relatively low cost of seed of these 

species will continue to appeal to those faced with the 

reality oflarge burns in cheatgrass-prone areas. 

Quantities of native seed adequate to supply the need 

following large fires in fire seasons such as 1996 can be 

facilitated by the methods that have put seed of introduced 

species in abundant supply. Selecting for high seed production, ease of harvest, vigorous germination, and rapid establishment and advanced harvest and massive storage of seed 

to be used in regional areas and not necessarily local areas 

might not fit well into a pure, local, native concept. However, 

the challenge presented to such a concept by cheatgrass and 

other aggressive, introduced, weedy species seems catastrophic. This challenge has been met by selection and 

marketing that has put seed of successful, perennial, introduced species in abundant supply. Similar selection and 

market development of native species is strongly indicated 

as a vital part of rangeland restoration including control of 

noxious weeds and other highly invasive species. 

References --------~-----------------------

Ashcroft, G. L.; Jensen, D. T.; Brown, J. L. 1992. Utah climate. 

Logan, UT: Utah State University, Utah Climate Center. 125 p. 

Billings, W. D.1994. Ecological impacts of cheat grass and resultant 

fire on ecosystems in the western Great Basin. In: Monsen, S. B.; 

Kitchen, S. G., compilers. Proceedings--ecology and management of annual rangelands; 1992 May 18-21; Boise, ID. Gen. 

Tech. Rep. INT-313. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station: 22-30. 

Davis,J. N.; Harper, K. T.1990. Weedy annuals and establishment 

of seeded species on a chainedjuniper-pinyon woodland in central 

Utah. In: McArthur, E. D.; Romney, E. M.; Smith, S. D.; Tuller, P. 

T., compilers. Proceedings-symposium on cheatgrass invasion, 

shrub die-off, and other aspects of shrub biology and management; 1989 April 5-7; Las Vegas, NV. Gen. Tech. Rep. INT-276. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 72-79. 

Evans, R. A; Young, J. A 1978. Effectiveness of rehabilitation 

practices following wildfire in a degraded big sagebrush-downy 

brome community. J. Range Manage. 31: 185-188. 

Everett, R. L. 1987. Plant response to fire in the pinyon-juniper 

zone. In: Everett, R. L., compiler. Proceedings-pinyon-juniper 

conference; 1986 Janurary 13-15; Reno NV: Gen. Tech. Rep. 152-

157. INT-215. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 152-157. 

Goodrich, S.; Gale, N. These proceedings. Cheatgrass frequency at 

two relic sites within the pinyon-juniper belt of Red Canyon. In: 

Monsen, Stephen B.; Stevens, Richard; Tausch, Robin J.; Miller, 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Rick; Goodrich, Sherel, comps. 1998. Proceedings: ecology and 

management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-OOO. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Rocky Mountain Research Station. 

Harris, G. 1967. Some competitive relationships between Agropyron spicatum and Bromus tectorum. Ecological Monographs. 

37: 89-111. 

Hironaka, M. 1994. Med usahead: natural successor to the cheatgrass 

type in the northern Great Basin. In: Monsen, S. B.; Kitchen, S. 

G., compilers. Proceedings-ecology and management of annual 

rangelands; 1992 May 18-21; Boise, ID. Gen. Tech. Rep. INT-313. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 89-91. 

Kindschy, R. R. (1994). Pristine vegetation of the Jordan Crater 

Kipukas: 1978-91. In: Monsen, S. B.; Kitchen, S.G., compilers. 

Proceedings-ecology and management of annual rangelands; 

1992 May 18-21; Boise, ID. Gen. Tech. Rep. INT-313. Ogden, UT: 

U.S. Department of Agriculture, Forest Service, Intermountain 

Research Station: 85-88. 

Knight, D. H. 1994. Mountains and plains: the ecology of Wyoming 

landscapes. New Haven, Conn., Yale University Press. 338 p. 

Leistritz, F. L.; Bangsund, D. A; Leitch,J. A 1996. Economic impact 

ofleafy spurge on grazing and wildlands in the Northern Great 

Plains. In: Quimby, C., moderator; Busby, F., facilitator. Proceedings of the alien plant invasions symposium; 1995 January 17: 

BLM/ORIWNPT-95/048+1792. U.S. Government Printing Office; Region No. 10: 15-21. 

McNab, W. H.; Avers, P. E.1994. Ecological subregions of the United 

States: Section descriptions. Administrative Publication WOWSA-5. Washington, DC: U.S. Department of Agriculture, Forest 

Service. 267 p. 

Monsen, S. B. 1994. The competitive influences of cheatgrass 

(Bromus tectorum) on site restoration. In: Monsen, S. B.; Kitchen, 

S. G., compilers. Proceedings-ecology and management of ann ual rangelands; 1992 May 18-21; Boise, ID. Gen. Tech. Rep. INT313. Ogden, UT: U.S. Department of Agriculture, Forest Service, 

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Nasri, M.; Doescher,P. S.1995a. Effect of competition bycheatgrass 

on shoot growth of Idaho fescue. J. Range Manage. 48: 402-405. 

Nasri, M.; Doescher, P. S.1995b. Effect oftemperature on growth of 

cheatgrass and Idaho fescue. J. Range Manage. 48: 406-409. 

Northam, F. E.; Callihan, R. H.1994. New weedy grasses associated 

with downy brome. In: Monsen, S. B.; Kitchen, S. G., compilers. 

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Research Station: 211-212. . 

Peters, E. F.; Bunting, S. C. 1994. Fire conditions pre- and postoccurrence of ann ual grasses on the Snake River Plain. In: Monsen, 

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Service, Intermountain Research Station: 31-36. 

Pyke, D. A; Novak, S. J. 1994. Cheatgrass demography-establishment attributed, recruitment, ecotypes, and genetic variability. In: Monsen, S. B.; Kitchen, S. G., compilers. Proceedings-ecology and management of annual rangelands; 1992 

May 18-21; Boise, ID. Gen. Tech. Rep. INT-313. Ogden, UT: U.S. 

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managerial impact of pinyon-juniper and cheatgrass fires. In: 

Monsen, Stephen B.; Stevens, Richard; Ta usch, Robin J.; Miller, 

Rick; Goodrich, Sherel, comps. 1998. Proceedings: ecology and 

management ofpinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-OOO. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

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Tausch, R. J.; Svejcar, T.; Burkhardt, J. W. 1994. Patterns of annual 

grass dominance on Anaho Island: implications for Great Basin 

vegetation management. In: Monsen, S. B.; Kitchen, S. G., compilers. Proceedings-ecology and management of annual rangelands; 1992 May 18-21; Boise, ID. Gen. Tech. Rep. INT-313. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

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ecosystem analysis and management handbook. FSH 2209-21. 

Ogden, UT: U.S. Department of Agrlculture, Forest Service, 

Intermountain Region. 4 ch. 

West, N. E; Van Pelt, N. S. 1987. Successional patterns in pinyonjuniper woodlands. In: Everett, R. L., compiler. Proceedingspinyon-juniper conference; 1986 January 13-16; Reno, NV: Gen. 

Tech. Rep. INT-215. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station: 43-52. 

Whitson, T. D.; Burrill, L. C.; Dewey, S. A; and others. 1991. Weeds 

of the west. The Western Society of Weed Science in cooperation 

with the Western United States Land Grant Universities Cooperative Extension Services. 630 p. 

Young, J. A 1994. History and use of semiarid plant communitieschanges in vegetation. In: Monsen, S. B.; Kitchen, S. G., compilers. Proceedings-ecology and management of annual rangelands; 1992 May 18-21; Boise, ID. Gen. Tech. Rep. INT-313. 

Ogden, UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 5-8. 

Young, J. A; Evans, R. A 1978. Population dynamics after wildfires 

in sagebrush grasslands. J. Range Manage. 31: 283-289. 

Young, J. A; Tipton, F. 1990. Invasion of cheatgrass into arid 

environments of the Lahontan Basin. In: McArthur, E. D.; Romney, E. M.; Smith, S. D.; Tueller, P. T., compilers. Proceedingssymposium on cheatgrass invasion, shrub die-off, and other 

aspects of shrub biology and management; 1989 April 5-7; Las 

Vegas, NV. Gen. Tech. Rep. INT-276. Ogden, UT: U. S. Department of Agriculture, Forest Service, Intermountain Research 

Station: 37-40. 

407 
Use of the Helitorch to Enhance Diversity on 

Riparian Corridors in Mature Pinyon-Juniper 

Communities: A Conceptual Approach 

G. Allen Rasmussen 

Robin Tausch 

Steve A. Bunting 

Abstract-As pinyon-juniper have increased their dominance 

throughout the Great Basin, other perennial plants have declined in 

abundance. Riparian areas traditionally have the greatest 

biodiversity found in the region. The increase of pinyon-juniper can 

generally be attributed to a change in the disturbance regime. To 

increase the plant diversity found in the riparian areas pinyonjuniper plants must be removed, but traditional methods, such as 

individual tree cutting, chaining, or herbicides, are not practical or 

acceptable in many cases. Fire has generally not been thought of as 

a viable alternative. A helitorch, with a fan nozzle, could be used to 

follow the riparian corridor and burn out pinyon-juniper trees when 

leaf moisture is lowest and weather conditions would restrict fire 

spread to just those trees where the fuel has been placed. Burned 

areas could be used to break up fuel continuity associated with 

mature pinyon-juniper communities. This would allow land 

managers to work with small areas to (1) break up fuel bed 

structure, (2) reestablish desired plants in both riparian and 

upland areas, and (3) enhance and restore plant diversity found in 

the Great Basin and Intermountain West. 

Pinyon-juniper communities have encroached into many 

new areas because of altered disturbance regimes in the 

Great Basin. This has primarily been due to changes in fire 

return intervals. In addition, occurrence of exotic annuals 

now make these communities susceptible to being invaded 

and dominated by these annuals once a disturbance occurs. 

This is particularly apparent on large-scale fire disturbances because of the difficulty often encountered in 

revegetation. Within the riparian corridors the loss of plant 

diversity and the increased erosion potential following 

large disturbances can lead to numerous negative consequences. Disturbances need to be gradually reintroduced 

into these systems. This would allow reestablishment of 

diverse species that could provide a seed source to aid in 

the recovery of the plant communities following larger 

disturbances. 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

G. Allen Rasmussen is with the Department of Rangeland Resources, Utah 

State University, Logan Ut 84322-5230. Robin Tausch is Project Leader with 

the U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Reno, NV. Steve A Bunting is with the Department of Range 

Science, University of Idaho. 

408 

Currently there are several disturbance practices available to treat riparian zones including mechanical, individual tree cutting, herbicides, and broadcast burning. All 

have distinct advantages and disadvantages, One approach 

that has not been considered is the use of a helitorch during 

periods when precise ignition placement and speed could be 

used to limit the scale ofthe fire and reduce soil disturbance. 

The helitorch has been developed to burn large complex 

units on forest and rangelands. It has been successful on 

these large units where hand ignition was not practical or 

safe (Masters and others 1986). This ignition tool has been 

very successful in treating redberry juniper (Juniperus 

pinchottii) communities (McPherson and others 1985) and 

Utah Juniper (J. osteosperma) (Brad Barber personal communication). However, the successful use of this ignition 

technique requires people with experience and the desire to 

burn large units, which limits its application (Masters and 

others 1986). This technique provides a very precise placement of the ignition pattern to develop sufficient heat to 

overcome many of the fuel discontinuities associated with 

rangeland fuels. While many have tried to use the helitorch, 

often the size ofthe units are not sufficient to be cost effective 

(Rasmussen and others 1988). In addition, many land managers felt that large units were often logistically impractical to 

treat. 

While this ignition technique is associated with large 

units it also has the capability to deal with smaller areas for 

specific objectives. We propose that many of the riparian 

corridors in the Great Basin where pinyon-juniper has 

become a dominate at he expense of the original riparian 

vegetation can be effectively restored using prescribed fire 

ignited with a helitorch. This can be done by precise placement of the fire and modifying the fire prescription to allow 

the fire to stay within the original riparian corridor. Nonsproutingjuniper and pinyon could be removed which would 

allow riparian vegetation to reestablish. Because of weather 

conditions at time of burning few personnel would be needed 

for containment which would reduce the cost of the burn. An 

added benefit would be to break up fuel continuity associated with mature woodlands. This practice could also be 

used to enhance fire manage capabilities especially if the 

associated ridges were burned in the same manner. 

Attempts of using spring burns in mature pinyon-juniper 

communities have been difficult because of the limited 

number of days that occur when weather conditions at this 

time in the season promote the desired spread of fires and 

amount of herbaceous fine fuel needed to carry the fire is 

often lacking. However, ignition of individual trees has been 

successful when the ignition source was placed directly on 

USDA Forest Service Proceedings RMRS-P-9. 1999 
the tree foliage (personal communication Stan Miller). 

Bunting and others (1976) found juniper readily ignited 

when leaf moisture was below 45 percent. Low moisture 

levels normally occur in the summer, but may also be 

encountered in the spring. Spring leaf moisture of Utah 

juniper in Cache County, Utah has been recorded as less 

than 40 percent in March and April. The ability to ignite 

individual trees appears to be related the leaf moisture of 

the juniper during this period of the year. 

Factors that limit the use of prescribed fire during the 

winter spring periods in the Great Basin can also be used to 

effectively burn small areas for the specific objectives. Reestablishment of a variety of communities in the riparian 

areas and uplands could be accomplished using this technique. In addition reducing continuous fuel beds by strategically placing corridors in the riparian areas and ridges 

could reduce the spread of wildfires. Instead of promoting 

large fires with 50 to 80 percent burn coverage, prescribed 

fires can be limited to those trees where the fuel is placed. 

Fire spread could be minimized by selecting the appropriate 

weather conditions. This would limit the disturbance to 

small areas that can be effectively restored with desired 

plant species. 

The helitorch provides an ignition source that could effectively ignite sufficient trees along a corridor (riparian or 

ridge) during the spring period. Since the rate offire spread 

is not the driving factor in developing prescription for burning, weather constraints would be greatly relaxed. A fire 

prescription could be developed which would increase the 

number of days that burning could be used. An additional 

advantage would be the increased availability of equipment 

which is normally not being used for fire suppression during 

this period. 

A modified helitorch with a fan nozzle was used to ignite 

1000-4000 ha units in West Texas (Masters and others 1986). 

The helicopter flew at 60-90 kmfhr, 30-50 m above the surface. 

This resulted in a 10 m swath with burning fuel in very m2. 

To ensure sufficient fuel lands on individual trees and 

increase the precision of fuel placement the helicopter would 

probably have to slow down. We would suspect from experience that 10 to 30 kmfhr may be sufficient. This would 

increase the amount offuel/m2. Table 1 provides an initial 

prescription range that would allow individual trees to 

ignite but limit fire spread. Research would have to be 

conducted to refine the prescriptions and the most desired 

speed and height needed to ignite the trees along a desired 

corridor. In most cases we suspect several passes of the 

helitorch would be required to create the desired corridor 

width. 

USDA Forest Service Proceedings RMRS-P-9. 1999 

Table 1-Proposed possible weather conditions in the Winter/spring 

that could be used to develop fire prescriptions to burn 

corridors in mature Pinyon-Juniper communities in the 

Great Basin. 

Weather conditions 

Temperature (F) 

Wind (mph) 

Relative humidity (percent) 

Cloud cover (percent) 

Juniper leaf moisture (percent) 

Winter/Spring 

40-80 

0-10 

10-50 

<25 

<45 

This approach while unconventional offers several advantages over existing methods of treatment managers 

can use to restore narrow corridors in pinyon-juniper 

comm uni ties. 

1. It has the potential to limit soil disturbance compared 

to most mechanical techniques and summer fires. 

2. Allows managers to work with small areas to increase 

the success of establishing desired plant community (diversity), which can then be used as a seed source when other 

disturbances occur. 

3. Can be used in remote rough sites. 

4. Can be incorporated in the large scale fire management 

plans to break up fuel bed structure and help in wildfire 

suppression. 

5. Application would be rapid though it is doubtful planning costs would change. 

Before this approach is used research or tests would need 

to be established to refine the prescriptions and decrease the 

risk of failures by burning under the wrong conditions. 

References _________ _ 

Bunting, S. A, C. M. Britton, H. A Wright, and C. M. Countryman. 

1976. Ignition temperature and leaf moisture relationships in 

Juniper. Fire Mange. Notes. 37: 143-146. 

McPherson, G. R, R A Masters, and G. A Rasmussen. 1985. 

Prescribed burning a chained redberry juniper community with 

a helitorch. Fire Manage. Notes. 46: 7-10. 

Masters, R A, G. A. Rasmussen, and G. R McPherson. 1986. 

Prescribed burning with a helitorch on the Texas rolling plains. 

Rangelands. 8: 173-176. 

Rasmussen, G. A, G. R McPherson, and H. A Wright. 1988. 

Economic comparison of aerial and ground ignition techniques for 

rangeland prescribed fires. J. Range Manage. 41: 413-415. 

409 
Wildfire Rehabilitation in Utah 

Linda MacDonald 

Abstract-The magnitude of the fire problem on arid rangeland in 

Utah was addressed, and effectiveness of common fire rehabilitation practices was compared. In lower elevations, and over much of 

Utah's arid environment, cheatgrass and other weedy species readily 

invade burned areas when the site specific reseeding mixture used 

is not planted (drilling) or covered (chaining). Aerial seeding followed by single chaining to cover the seed proved to be a very 

effective method of establishing perennial vegetation, maintaining 

species diversity, and inhibiting the spread of weedy species. It 

was noted that old seedings, containing fire resistant and fire 

tolerant species of vegetation, remained green longer into the fire 

season, and made natural fire-breaks, thereby helping to contain 

the wildfire. 

Land administered by the Bureau of Land Management 

(BLM) in Utah is generally arid, receiving 8-12 inches of 

precipitation per year. Acres ofBLM land burned by wildfire 

has increased from 4,549 acres in 1991, to 308,457 acres in 

1996 as shown in the following tabulation: 

Year 

1991 

1992 

1993 

1994 

1995 

1996 

BLMacres 

burned 

4,549 

7,439 

11,928 

116,021 

127,900 

308,457 

The increase in number of acres burned is due in part to the 

invasion of introduced winter ap.nuals such as cheatgrass 

(Bromus tectorum), and past fire suppression activities. 

Cheatgrass not only changes the fire frequency of a site, but 

also the fire volatility, intensity and extent of the area likely 

to burn in the future. 

Objective 

The purpose of the Emergency Fire Rehabilitation program is to: Protect life, property, soil, water and/or vegetation resources; Prevent unacceptable on-site and off-site 

damage to the watershed (erosion control); Reduce invasion 

and establishment of undesirable or invasive species of 

vegetation, and; Facilitate meeting Land Use Plan objectives. The purpose of this study was to compare various 

In: Monsen, Stephen B.; Stevens, Richard, comps. 1999. Proceedings: 

ecology and management of pinyon-juniper communities within the Interior 

West; 1997 September 15-18; Provo, UT. Proc. RMRS-P-9. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research 

Station. 

Linda MacDonald is a Range Management Specialist, Bureau of Land 

Management, Utah State Office, P.O. Box 45155, Salt Lake City, UT 84145. 

410 

treatment methods of wildfire rehabilitation for meeting 

the stated objectives, keeping in mind the cost associated 

with each method of treatment. 

Methods and Results 

In all seeding methods, mixtures of grasses, forbs and 

shrubs that are adapted to the site were used. Exception: On 

some sites with State listed noxious forbs, a mixture of 

native and introduced grasses adapted to the site was used. 

Forbs and shrubs will be seeded after the noxious weed 

problem is controlled by spraying. 

Preci pitation following the seeding was above normal, and 

winter temperatures were warmer than normal. Results 

described, therefore, are from the best possible climatic 

conditions to be expected in the area. 

Natural Revegetation, No Seeding 

(Control Area) 

Control areas were examined to determine their natural 

recovery. In higher elevations where sufficient moisture and 

a diverse population of perennial vegetation exists, these 

areas recovered sufficiently to protect the watershed, especially on the north and east facing slopes. Response of native 

vegetation was not as good on south and west facing slopes, 

which are typically drier. 

Below 6,000 ft elevation, and in much of Utah's arid 

environment, cheatgrass and other weedy species readily 

invaded the burned areas. These areas did not respond 

naturally with sufficient perennial vegetation to protect the 

watershed from wind and water erosion, and weed invasion. 

Seed by Aerial Application Only Without 

Coveri ng the Seed 

Seed was flown over 102,100 burned acres in the rehabilitation area. Ofthis number, 55,200 acres were aerial seeded 

only, with no disturbance to the soil. These areas were then 

compared with areas that were not seeded (control areas), 

areas where seed was planted by drill, and with areas that 

were seeded and then chained to cover the seed. 

While a small percent of the uncovered seed germinated 

and became established, it was not in sufficient quantity to 

protect the soil from erosion. In areas of high winds, the seed 

was blown to unburned islands, and roadside gullies. There 

it was covered with topsoil lost from the site due to wind 

erosion. The seed became established in these disturbed 

areas. Pedestaling of the exposed plant roots, showed that 

up to four inches of topsoil was lost due to wind erosion in 

some areas that had been seeded, where the seed was not 

covered. 

USDA Forest Service Proceedings RMRS-P-9. 1999 
Seed by Aerial Application Followed by 

Chaining to Cover the Seed 

The seed mixture was flown on the treatment area, followed by one-time chaining to cover the seed. In addition, in 

some areas, seed dribblers were placed so that shrub seeds 

were planted by the action of the heavy equipment in areas 

being chained. In 1996, some areas suitable for drilling seed 

were aerial seeded instead because of the vast acreage 

needing immediate treatment following wildfire. More than 

twice as many acres could be covered per day, by using this 

method. 

Covering the seed with one-time chaining, proved to be 

very effective in establishing perennial vegetation to protect 

the site from wind and water erosion. This seeding method 

helped establish and maintain species diversity, and inhibit 

the spread of cheatgrass and other- weedy species. 

Drill Seeding 

Sixteen thousand one hundred fifty acres were seeded by 

rangeland drills. Most exhibited a high germination response, the exception being the sand dunes at Little Sahara 

Recreation Area. In most cases, drilling effectively planted 

the seed mix, and inhibited the spread of cheatgrass and 

State listed noxious weeds. 

Discussion _________ _ 

Study plots have been identified for long term monitoring 

of the treatment areas, by BLM and by the U.S. Forest 

Service Shrub Laboratory. Observations discussed below 

pertain to results of rehabilitation, the first year following 

treatment. 

Natural Revegetation 

In higher elevations (above 6,000 ft) where sufficient 

moisture and a diverse population of perennial vegetation 

exists, reseeding is often not needed, especially on the north 

and east facing slopes. However south and west facing 

slopes, which are typically drier, would likely benefit from 

seeding. 

Below 6,000 ft elevation, and over much of Utah's arid 

environment, cheatgrass and other weedy species readily 

invade burned areas. The dominance of cheat grass shortens 

the fire cycle, and increases the volatility and extent of the 

fire. Also because cheatgrass does not catch and hold snow 

like a diverse perennial stand of vegetation, the site becomes 

drier (desertification). On sites dominated by cheatgrass, 

the normal revegetative process is interrupted resulting in 

loss of native perennial species, and lack of diversity. 

Dense stands of pinyon-juniper often lack a diverse understory. When wildfire removes the canopy, there is not sufficient perennial seed available in the soil to protect the site 

from wind and water erosion. 

Aerial Seeding Without Covering the Seed 

This method did not result in adequate perennial vegetation to protect the watershed. Invasive introduced weeds 

such as cheatgrass and State listed noxious weeds readily 

invaded the sites. In areas with highly erosive soils, wind 

and water erosion is evident. It was also determined aerial 

USDA Forest Service Proceedings RMRS-P-9. 1999 

broadcast seeding without covering the seed was not cost 

effective over large areas in Utah's arid environment. 

Aerial Seeding Followed by Chaining to 

Cover the Seed 

This method of covering the seed proved to be a very 

effective in establishing perennial vegetation on areas with 

slopes and gullies, rocky outcrops, and areas with dead tree 

stumps and debris. This treatment is highly effective in 

protecting the site from wind and water erosion. These 

seedings helped establish and maintain species diversity, 

and inhibit the spread of cheat grass and other weedy species. 

Aerial seeding followed by one-time chaining to cover the 

seed also proved to be a practical and relatively inexpensive 

method to use when large acreage needs to be treated (over 

300,000 acres of BLM land burned in 1996). With this 

method, 250 acres could be treated per day, as compared to 

drilling the seed at 100 acres per day. 

Drill Seeding 

Areas that were seeded by drilling had the highest germination response. But drilling could only be used on level 

areas free from obstacles. Therefore drilling wasn't possible 

in pinyon-juniper sites, rocky outcrops, and areas with 

washes or channels, and on slopes. 

Additional Benefits of Seeding 

Where wildfire burned into old seedings, it's advance was 

slowed or stopped in that direction, in spite of strong winds. 

The seedings, which contain fire resistant and fire tolerant 

species of vegetation, remain green longer into the season. 

There are numerous examples where old seedings make 

natural fire-breaks, thereby helping to contain the wildfire. 

Acknowledgments 

The author expresses appreciation to the personnel at the 

BLM Fillmore Field Office who did all the on-the-ground 

work, and to Glenn Foreman and Kelly Rigby, Utah State 

Office for photographs and assistance in preparing the 

poster. 

References _________________ __ 

Clary, Warren P. Plant density and cover response to several 

seeding techniques following wildfire. Research Note INT-384, 

6 pp. U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 

Everett, Richard; Clary, Warren. Fire effects and revegetatio!l on juniper-pinyon woodlands. Rangeland fire effects: a symposIUm, 

Boise, ID.1984November 27-29. Idaho State Office, D..S. Department of Interior, Bureau of Land Management, BOIse, Idaho. 

1985. (33-37). 

Farmer, Mark E.; Harper, Kimball T.; Davis, James~. 19.97 .. The 

influence of anchor-chaining on watershed health m a Jumperpinyon woodland in central Utah. In: Ecology and management of 

pinyon-juniper communities within the interior west symposium; proceedings; 1997 September 15-18;. Provo, UT. 

Monsen, Stephen B.; Pellant, Mike. 1997. Seedmg burned shrublands 

by aerial broadcasting and a~ch?r chaining. 1~~7. In; E~ology 

and management of pinyon-Jumper commumtIes wlthm the 

interior west symposium; proceedings; 1997 September 15-18; 

Provo, UT. 

411 

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