U.S. Department of the Interior

U.S. Geological Survey

Piñon and Juniper Field Guide: 

Asking the Right Questions to 

Select Appropriate 

Management Actions

Circular 1335
Photograph taken by Robin Tausch
Piñon and Juniper Field Guide: 

Asking the Right Questions 

to Select Appropriate 

Management Actions

By R.J. Tausch, U.S. Forest Service Rocky Mountain 

Research Station, R.F. Miller, Oregon State University, B.A. 

Roundy, Brigham Young University, and J.C. Chambers, U.S. 

Forest Service Rocky Mountain Research Station

Circular 1335

U.S. Department of the Interior

U.S. Geological Survey

This is contribution number 02 of the Sagebrush Steppe 

Treatment Evaluation Project (SageSTEP), supported by 

funds from the U.S. Joint Fire Science Program. Partial 

support for this guide was provided by the U.S. Geological 

Survey Forest and Rangeland Ecosystem Science Center.
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2009

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Suggested citation:

Tausch, R.J., Miller, R.F., Roundy, B.A., and Chambers, J.C., 2009, Piñon and 

juniper field guide: Asking the right questions to select appropriate management 

actions: U.S. Geological Survey Circular 1335, 96 p.

Edited and Designed by: Summer C. Olsen and Elizabeth A. Didier, Outreach 

Program Coordinators, Utah State University, Logan, Utah State University

All photographs in this guide were taken by Richard Miller and Robin Tausch 

unless otherwise noted.
Contents

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

Questions to be Addressed......................................................8

Setting Goals and Objectives.................................................12

Part I: The Ecological Site ......................................................14

Part II: The Current State of the Site ..................................45

Part III: Landscape Considerations ......................................67

Part IV: Selecting Appropriate Management Actions and 

Treatments ..................................................................71

Appendix 1: Field Assessment Form....................................89

Appendix 2: Species Codes...................................................91

Glossary of Terms ....................................................................92
Figures

Figure 1. Piñon and juniper encroachment at upper 

Underdown Canyon, Shoshone Mountains, 

central Nevada ......................................................1

Figure 2. Current distribution of western juniper 

(Juniperus occidentalis) in the western 

United States..........................................................3

Figure 3. Current distribution of Utah juniper 

(Juniperus osteosperma) in the western 

United States..........................................................4

Figure 4. Current distribution of singleleaf piñon 

(Pinus monophylla) in the western United 

States.......................................................................5

Figure 5. Current distribution of Colorado piñon 

(Pinus edulis) in the western United States......6

Figure 6. Phase II woodland...............................................13

Figure 7. Ecological Provinces of the southwestern 

United States........................................................15

Figure 8. Soil texture triangle.............................................17

Figure 9. Mountain big sagebrush/Idaho fescue 

plant association with moderately deep 

(>30 in.), well-drained, clay loam soils.............18

Figure 10a. A shallow restrictive soil layer limits tree 

rooting depth resulting in a loss of shrubs, 

grasses, and forbs...............................................19

Figure 10b. Former Wyoming big sagebrush community 

on a site with a restrictive soil layer similar 

to fig. 10a. now fully dominated by Utah 

juniper ..................................................................19

Figure 11. Dead bitterbrush and big sagebrush remnants 

can be distinguished by differences in 

the wood; bitterbrush (top) is clear while 

sagebrush (bottom) has dark brown bands 

perpendicular to the annual growth rings.......21
Figures—Continued

Figure 12. Diagnostic sagebrush community species 

oriented along a general warm-dry to 

cool-wet gradient ................................................21

Figure 13. Common sagebrush species and 

subspecies associated with pinon-juniper 

woodlands.............................................................23

Figure 14. Examples of the range of variation in 

old-growth woodland sites ................................35

Figure 15. An open old-growth Utah juniper dominated 

shrub savanna in east-central Nevada ...........37

Figure 16. Old-growth Utah juniper and singleleaf 

piñon with dead branches and missing 

bark ........................................................................38

Figure 17. Bark characteristics of species of 

woodland trees of different ages......................40

Figure 18. Mountain big sagebrush/bluebunch 

wheatgrass plant association with a stand 

of pre-settlement Utah juniper trees 

growing on shallow soils....................................41

Figure 19. Wyoming big sagebrush community with 

charred stumps on shallow to moderately 

deep soils that indicate a low density of 

trees has occupied the site since prior to 

the mid-1800s........................................................42

Figure 20. Relation of time since fire and the percent 

composition (dominance) of grasses, 

shrubs, and trees.................................................43

Figure 21. Phase II piñon-juniper expansion 

woodlands in a mountain big sagebrush 

community with a high level of structural 

diversity.................................................................45
Figures—Continued

Figure 22. Leader growth, particularly for trees 

<3m tall, is a good indicator of competition 

among trees..........................................................47

Figure 23. Three phases of woodland succession in 

piñon-juniper woodlands ...................................50

Figure 24. Conceptual model with estimated time periods 

form initial woodland establishment (early 

Phase I) to minimum stocking adequate 

to reach Phase III with tree growth, and 

estimated maximum potential for relative 

abundance and cover for stands developing 

on sites from high to low productivity .............52

Figure 25. Relation between age and tree height 

across a range of tree dominance on 

relatively productive piñon-juniper sites: 

tree height of dominant and co-dominant 

individuals more than two meters tall can 

be used as a coarse proxy to estimate 

stand age ..............................................................53

Figure 26. Third growing season after a high-severity 

fire in a high-productivity Phase III 

expansion piñon-juniper site .............................57

Figure 27. Rapid expansion and growth of piñon-juniper 

has led to bare ground and dead shrub 

skeletons...............................................................59

Figure 28. This site lacks both woody and herbaceous 

understory to carry a fire and adequate 

desirable herbaceous species for 

restoration.............................................................60

Figure 29. A Phase III Utah juniper site with large areas 

of bare ground potentially susceptible to 

accelerated runoff and erosion ........................62
Figures—Continued

Figure 30. A piñon-juniper site with large, connected 

zones of bare ground and water flow 

patterns in the inter-canopy ..............................63

Figure 31. Tree cavity in the trunk of an old-growth 

singleleaf piñon....................................................65

Figure 32. Example of juniper resprouting after 

chainsaw cutting left a lower limb ...................73

Figure 33. An example of tree mastication 

(bullhogging) on a juniper-dominated site

in western Utah....................................................74

Figure 34. Piñon-juniper chainsaw cutting in 

woodlands.............................................................76

Figure 35. Understory responses 2 years after 

prescribed fire in Phases I, II, and III piñonjuniper dominated Wyoming big sagebrush 

communities in eastern Nevada .......................80

Figure 36. Thirty-five-year-old north-slope wildfire 

that burned through Phase III expansion 

piñon-juniper woodlands ...................................82

Figure 37. Moderate-severity fire where 80% of the native 

species in the understory survived; 

no seeding is required ........................................85

Figure 38. Examples of high-severity fire where 

mortality of native herbaceous species 

was >80% .............................................................86
Tables

Table 1. Morphological characteristics of postsettlement (<150 years) and pre-settlement 

(>150 years) woodland trees ............................30

Table 2. Stand characteristics differentiating three 

transitional phases of woodland succession 

for most sagebrush associations......................54

Keys

Key 1. Common sagebrush species and subspecies 

associated with piñon-juniper woodlands......22

Key 2. Identifying ecological site and estimated fire 

return interval (FRI) .............................................32
Introduction

1

Introduction

Piñon-juniper woodlands are an important 

vegetation type in the Great Basin. Old-growth and 

open shrub savanna woodlands have been present 

over much of the last several hundred years. Strong 

evidence indicates these woodlands have experienced 

significant tree infilling and major expansion in their 

distribution since the late 1800s by encroaching into 

surrounding landscapes once dominated by shrubs 

and herbaceous vegetation (fig. 1). Both infilling and 

expansion affects soil resources, plant community 

structure and composition, water and nutrient cycles, 

(b)

(a)

Figure 1. Piñon and juniper encroachment at upper 

Underdown Canyon, Shoshone Mountains, central Nevada, (a) 

1973 and (b) 2007. 
Introduction

2

forage production, wildlife habitat, biodiversity, and fire 

patterns across the landscape. Another impact is the shift 

from historic fire regimes to larger and more intense 

wildfires that are increasingly determining the future of 

this landscape.

The major goal of woodland management is 

to reverse these changing patterns by attempting to 

restore a functioning and resilient ecosystem through 

a more balanced plant community, which in areas of 

woodland expansion include a robust assemblage of 

grasses, forbs, and shrubs. With a robust assemblage 

of perennial grasses and forbs, in particular, a properly 

functioning ecosystem is better able to resist dominance 

by cheatgrass and other exotic weed species after fire or 

other disturbances. Even with prevention, maintenance, 

or restoration efforts to reduce trees by mechanical 

methods or prescribed fire, significant management will 

also be directed towards treatment following wildfire. 

Developing a management approach for implementing 

either preventive treatments or post wildfire restoration 

can be a difficult task. This is because of uncertainty 

about how the vegetation, soils, hydrologic function, and 

wildlife will respond to treatment. 

Woodlands in the Great Basin represent a complex 

mix of trees, sagebrush, other shrubs, perennial and 

annual forbs, perennial grasses, and non-native grass 

and forb invaders. In different parts of the region, the 

distributions of four tree species overlap. These species 

include western juniper (fig. 2), Utah juniper (fig. 3), 

singleleaf piñon (fig. 4), and Colorado piñon (fig. 5). 

They occur alone or in mixes of two or rarely three 

species. The distributions of these tree species combined 

encompass nearly the full range of sagebrush species 

and subspecies, plus other shrub grass, and forb species. 

Responses to disturbances, such as insect outbreaks, 

drought and wildfire, or preventive or restoration 

treatment usually varies with the mix of tree, sagebrush, 

and perennial grass and forb dominants present on the 

site. 
Introduction

3

Figure 2. Current distribution of western juniper (Juniperus 

occidentalis) in the western United States (from Miller and 

others, 2007).
Introduction

4

Figure 3. Current distribution of Utah juniper (Juniperus 

osteosperma) in the western United States (from Little, 1971).

When developing a management strategy, the first 

and possibly most important step towards success is 

asking the right questions. Identifying the attributes

of the area to be treated, including the vegetation 

composition, soils, slope, aspect, elevation, geology, 

and ecological province, and then selecting the right 

treatments to be applied are of utmost importance. To 

best match long-term goals and objectives to the site, it 

can be beneficial to assess potential natural vegetation, 

soils, and the current successional and hydrologic 

states of the site. This allows us to best determine 

what components need to be restored to meet realistic 

objectives. In addition to the site conditions, it is equally 

important to determine how the management unit fits in 
Introduction

5

Figure 4. Current distribution of singleleaf piñon (Pinus 

monophylla) in the western United States (from Little, 1971).
Introduction

6

Figure 5. Current distribution of Colorado piñon (Pinus edulis) 

in the western United States (from Little, 1971).

the overall landscape mosaic, including the potential for 

wildfire. Keep in mind that sagebrush-steppe vegetation 

is dynamic, and management strategies will be most 

effective if multi-decade time frames are taken into 

account, particularly when piñon and juniper trees are 

present. 

This guide provides a set of tools to help field 

biologists; land managers, including fuels specialists 

and fire managers; representatives of NGO’s; and private 

landowners conduct rapid, qualitative field assessments 

that address a site’s potential, current state, and relation 

to the surrounding landscape. These tools include a list 

of questions to be addressed and a series of photographs, 
Introduction

7

keys, tables, and figures to aid in site evaluation. This 

assessment is designed to help prioritize sites to be 

treated, select the best treatment, and help predict 

outcomes. 

Success of a piñon and juniper management 

program may be greatly enhanced if an interdisciplinary 

team of experienced local managers and resource 

specialists use this guide as an aid in decision-making. 

Knowledge of vegetation, fuels, potential fire patterns, 

soils, hydrology, grazing, wildlife, and their relationships 

to the surrounding landscape, as well as economic 

and sociological aspects of the local area, are essential 

to successful management and implementation of 

treatments. 

Supporting Literature

This piñon-juniper guide closely corresponds to 

the publication Western Juniper Field Guide: Asking 

the Right Questions to Select Appropriate management 

Actions by Richard Miller and others (U.S. Geological 

Survey Circular 1321, 2007) (fig. 2). It also is closely 

linked to the synthesis publications 

•	 Biology, Ecology, and Management of Western 

Juniper by Richard Miller and others (Oregon 

State University Agricultural Experiment Station 

Technical Bulletin 152, 2005); 

•	 Age Structure and Expansion of Piñon-Juniper: 

A Regional Perspective in the Intermountain West

by Richard Miller and others (U.S. Department of 

Agriculture, Forest Service, Research Paper Report 

RMRS-RP-069, 2008); 

•	 Fire related restoration issues in woodlands 

and rangeland ecosystems by Jeanne Chambers, 

(Mixed Fire Regimes: Ecology and Management 

Symposium Proceedings, in L. Taylor, J. Zelnik, S. 

Ladwaller, and B. Huges (compilers), November 

11-19, 2004, Spokane, WA. AFE MIXC03); 
Introduction

8

•	 Piñon-Juniper Woodlands by Robin Tausch and 

Sharon Hood, Chapter 4 in: Fire Ecology and 

Management of Major Ecosystems of Southern 

Utah, (U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Research Station, General 

Technical Report, RMRS-GTR-202, 2007); and 

•	 Atlas of United States Trees (U.S. Department of 

Agriculture, Forest Service, Washington, D.C., 

Miscellaneous Publication No. 1146, 1971) (figs. 

3-5). 

Please refer to these publications for more information 

and for literature cited.

Questions to be Addressed

This field guide is meant to help personnel from 

management agencies, NGO’s, environmental groups, 

and private landowners with a thought process of how 

to look at the landscape and determine what questions 

to ask to meet specified goals and objectives. These 

questions are meant to provide a base or starting point 

for selecting an appropriate preventive, maintenance, 

or restoration management action or post-wildfire 

management response. Because each management unit 

and its relationship to the surrounding landscape are 

unique, additional questions may need to be addressed or 

modified to help evaluate the site. The guide is separated 

into four parts important for identifying the attributes of 

an area and selecting the appropriate management action. 

These components help to clearly define or set goals 

and objectives through identifying (I) The Ecological 

Site, (II) The Current State of the Site, (III) Landscape 

Considerations, and (IV) Selecting the Appropriate 

Management Action. The right questions also need to 

address agency procedures and meet the overall goals of 

the project. 
Introduction

9

Setting Goals and Objectives

The following questions are written from the 

perspective of implementing a preventive, maintenance, 

or restoration treatment, but are easily adaptable for 

application to post-wildfire management responses. 

What is to be done to a site should be based on clear and 

measurable objectives. This field guide also can help 

managers evaluate the site and incorporate decisions 

into the Resource Management Plan, Land Use Plan, or 

Forest Plan of their agency. 

1. What are the desired ecological conditions or how 

should the site look in 5, 10, 20, or 50 years? 

2. What vegetation changes need to occur on the site, 

and possibly over the surrounding landscape, to 

meet functional goals or habitat needs?

Answers to the questions in Parts I, II, and III are 

intended to help managers and others determine feasible 

goals and objectives for a particular site. As a result, 

goals and objectives should be re-evaluated as these 

questions are answered. 

Part I: The Ecological Site

3. In which Ecological Province is the site located? 

4. What is the elevation and topography?

5. What kinds of soils are present on the site?

6. How will the soils and physical features affect 

erosion and vegetation establishment?

7. What are the dominant plant species currently 

present, and what is the current and future potential 

natural vegetation (PNV) or plant association?

8. Are there old-growth trees on the site, and where are 

they growing?

9. Is the PNV estimated to be woodland or shrubsteppe, and what is the estimated fire return interval?

10. What is the ecological site?
Introduction

10

11. Prior to European settlement, what would the 

potential disturbance regime (frequency, intensity, 

and kinds of disturbance) have been, and how would 

different scenarios of this regime influence the 

historic range of vegetation variability on the site? 

12. How have post-settlement changes in vegetation or 

disturbance affected the vegetation and ecological 

conditions of the surrounding landscape?

13. What is the potential wildlife habitat value under 

current compared to potentially restored conditions? 

Part II: The Current State of the Site

14. Clearly define the perceived problems: What are the 

factors affecting proper ecological function?

15. What is the stage of woodland succession (Phase I, 

II, or III), and how does this vary across the site?

16. What is the current understory herbaceous 

composition?

17. Is there current recruitment of native understory 

species?

18. Are there invasive plant species adjacent to the site 

to be treated? 

19. What is the percentage of dead shrubs on the site, 

and what are the species? 

20. What are the fuel characteristics, and what type of 

fire will the site support? 

21. Are there signs of erosion and overland flow? What 

is the current capacity of the site to capture, store, 

and safely release water? What is the incidence of 

high-intensity summer thunderstorms? 

22. What is the current wildlife habitat suitability, and 

what species are involved? How will treatment 

affect wildlife species? 

23. Are there social and/or economic concerns or issues 

related to the site?
Introduction

11

Part III: Landscape Considerations

24. What are the spatial landscape characteristics of the 

area to be treated with respect to topography, patch 

size, edge, and connectedness? 

25. What is the composition of adjacent patches, what is 

the landscape distribution of patches, and what are 

their stages of woodland succession? 

26. What is the current variation in understory 

composition and in the recruitment of native 

understory species over the surrounding landscape? 

27. How do fuel characteristics of tree, shrub, and 

herbaceous layers vary over the surrounding 

landscape, what type of fire are they likely to 

support, and how might this influence the types of 

fire possible on the site? 

28. Are there signs of erosion and overland flow from 

the surrounding landscape that suggest impacts to 

the site? 

29. Will conditions of the surrounding area influence 

the wildlife habitat suitability of the site or affect the 

species involved? 

30. What are current uses, management activities, and 

social and economic concerns for the surrounding 

landscape that might affect the site? 

Part IV: Selecting the Appropriate Management 

Actions and Treatments

31. What are the factors that will influence selection of 

preventive, maintenance, or restoration treatments, 

including personnel availability, grazing schedules, 

and wildlife risk? 

32. What are treatment options, including mechanical, 

prescribed fire, cut and burn combinations, chemical 

applications, and seeding? 

33. How will post-treatment management, including 

the need for maintenance on the site, affect site 

conditions and function on the surrounding 

landscape? 
Setting Goals and Objectives

12

Setting Goals and Objectives

1. What are the desired1 ecological conditions 

or how should the site look in 5, 10, 20, or 50 

years? 

Desired1 ecological conditions depend on 

management objectives, potential uses for the site, 

and ecological characteristics of the site, such as soil 

profiles and ecological site type. Managers need to 

identify conditions that are ecologically, physically, 

and economically possible on a given landscape and 

that will satisfy management objectives over the longterm. Knowing these conditions can help determine if a 

treatment or series of treatments could help to achieve 

those results. 

Setting goals and objectives will often require 

participation by stakeholders, who may have differing 

or even conflicting ideas about the values that should be 

emphasized in woodland-dominated ecosystems such 

as the appropriate ecological condition of those lands. 

Natural disturbances and changes in environmental 

conditions, such as those associated with climate change, 

also may affect the site and necessitate adjustments in 

management plans. 

Because goals and objectives are influenced by 

many factors, they should be reevaluated and adjusted 

as new information becomes available. Answers to 

the questions that follow will provide information for 

managers and others that will help them in the ongoing 

1

Words such a “desired”, or “desirable”, and “best” are sometimes 

used to describe advantageous or suitable management approaches 

relative to management goals and objectives and in considerations 

of ecological responses of vegetation, soils, hydrologic function, 

and wildlife. These terms are used with recognition that many 

factors besides the evaluations described or cited in this manual may 

eventually come to bear in a decision-making process. In this context, 

these words should be viewed as relative terms only, not explicit 

directives or judgments. 
Setting Goals & objectives

13

process of setting appropriate goals and objectives for a 

particular site. 

2. What vegetation changes need to occur on 

the site, and possibly over the surrounding 

landscape, to meet functional goals or habitat 

needs? 

After a “desired condition” has been defined (for 

example, fig. 6), the next step is to identify the specific 

vegetation changes necessary for the site to meet 

functional goals, such as improved watershed health or 

wildlife habitat. For example, an increase in shrubs and 

herbaceous vegetation may be needed to increase vertical 

structural diversity for wildlife. Also, a reduction in 

trees can reduce evapotranspiration, thereby increasing 

soil moisture and water availability. Maintaining an 

open tree canopy with a diverse understory may help 

achieve these habitat goals. An increase in shrubs could 

change structural diversity to affect fuels and maintain 

a desired fire regime. Increases in perennial grass and 

forb cover may reduce erosion and sedimentation and 

Figure 6. Phase II woodland. A management objective for this 

site might be to maintain a diverse understory by reducing tree 

dominance. 
The Ecological Site

14

also enhance the ability of the site to capture and store 

water. In addition, increases in perennial grass and forb 

cover often can decrease the invasion of potential exotic 

species. All of these vegetation changes could help in 

meeting the desired goal of watershed health or wildlife 

habitat.

Part I: The Ecological Site

Determination of the Ecological Site is based 

on the premise that specific physical and climatic 

characteristics are capable of producing certain types 

of vegetation. Ecological site and soil maps for the 

area should be obtained and used to help determine the 

proper ecological site description, soils, and potential 

vegetation. Maps should be verified during a site visit to 

ensure that the descriptions match the site. 

3. In which Ecological Provinces is the site 

located?

The Great Basin is a region of complex topography, 

geology, and climate. The mountain ranges and 

intervening valleys vary greatly in size, elevation, 

configuration, and climate, all of which significantly 

affect vegetation. Environmental conditions on a 

particular mountain range are dependent not only on the 

topographic characteristics of the mountain range the site 

is located on, but also on the topographic characteristics 

and configuration of the surrounding ranges and valleys. 

Woodlands within Ecological Provinces are more 

similar in climate, topography, elevation, geology, soils 

floristic composition, and soil-plant relations than those 

across Ecological Provinces. Most of the dominant tree, 

shrub, and perennial grass species have wide ecological 
The Ecological Site

15

tolerances, and thus are expected to have more uniform 

responses within an Ecological Province compared 

to anywhere else they occur. A species response to 

disturbance or treatment may vary depending on the 

species location. Differences between the Ecological 

Provinces in altitude, topography, environment, geology, 

and vegetation can affect the outcomes of natural 

disturbances or treatments. The different Ecological 

Provinces are illustrated in figure 7.

Figure 7. Ecological Provinces of the southwestern United 

States. Adapted from West, N.E., R.J. Tausch, and P.T. Tueller. 

1998, A management-oriented classification of piñon-juniper 

woodlands of the Great Basin: U.S. Forest Service General 

Technical Report RMRS-GTR-12.
The Ecological Site

16

4. What is the elevation and topography?

Within the complex geology of the Great Basin, 

topography (primarily slope and aspect) combined with 

elevation can have a substantial effect on the soil type 

and the plant community. These factors influence how 

a site will respond to natural disturbance and applied 

treatments. For example, resilience and resistance to 

disturbance and potential for successful restoration often 

increases with elevation and more northerly aspects. 

Increasing elevation and shifts in aspect from south 

to north often result in cooler temperatures, greater 

moisture availability, and more productive soils. These 

differences also vary with Ecological Province, site 

topography, the spatial relatiohship, and topographic 

differences of surrounding mountain ranges.

5. What kinds of soils are present on the site?

A soils map of the site or area will indicate 

what type of soils are present. Soil depth, texture, 

structure, and organic matter content are important soil 

characteristics that influence water infiltration rates, 

water holding capacity, soil water availability for plants, 

and erosion potential. Loamy soils, which have a more 

balanced mixture of sand, silt, and clay (fig. 8) have 

better soil-water characteristics for plant growth than 

excessively drained sandy soils with low water-holding 

capacity or clay soils with low infiltration rates and very 

tightly held water.

Soil Texture (fig. 8): To determine soil texture of 

each horizon, add water to a healthy tablespoon of soil 

until you can roll it up in a ball without it leaving soil on 

your palm.
The Ecological Site

17

Press the soil between your thumb and forefinger 

and attempt to form a ribbon.

•	 Good Ribbon: does not break and has few cracks = 

high clay content

•	 Medium Ribbon: ribbon cracks deeply and 

eventually breaks = moderate clay content

•	 Poor Ribbon: a ribbon cannot be formed or 

immediately breaks = low clay content

Add additional water and test for smoothness and 

grit. Gritty texture indicates sand.

Soil Depth: Soil depth is measured from the surface 

to the layer that retards root development:

Very shallow: <10 in.

Shallow: 10 to 20 in.

Moderately deep: 20 to 36 in.

Very deep: >60 in.

Figure 8. Soil texture triangle (from Miller and others, 2007).
The Ecological Site

18

Restrictive soil layers increase below-ground 

competition. With increasing tree dominance, herbaceous 

vegetation is likely to decrease on sites where there is a 

restrictive soil layer 16 to 18 in. beneath the surface. Soil 

layers (for example, heavy clay argillic layer, petrocalic 

horizon, duripan, lithic contact, etc.) that restrict water 

movement also will influence water runoff on the site 

(fig. 9), and this should be considered before treatment. 

Where increasing tree dominance is causing the greatest 

decrease in understory (fig. 10) are often sites that are 

most susceptible to exotic annuals such as cheatgrass.

Figure 9. Mountain big sagebrush/Idaho fescue plant 

association with moderately deep (>30 in.), well-drained, 

clay loam soils. Juniper roots are well distributed throughout 

the soil profile resulting in a loss of shrubs, but Idaho fescue 

persists in the understory. 
The Ecological Site

19

Figure 10a. A shallow restrictive soil layer limits tree rooting 

depth resulting in a loss of shrubs, grasses, and forbs. 

Figure 10b. Former Wyoming big sagebrush community on 

a site with a restrictive soil layer similar to fig. 10a now fully 

dominated by Utah juniper. 
The Ecological Site

20

6. How will the soils and physical features affect 

erosion and vegetation establishment? 

Soil surface characteristics, slope, incidence of 

intense summer thunderstorms, and wind influence 

risk of erosion following tree removal treatments. Soil 

surface stability, soil texture, soil depth, aggregate 

stability, patterns of bare ground, and evidence of rill and 

sheet erosion should be examined across the site. These 

factors in combination with slope interact to determine 

erosion potential. Treatments like prescribed fire may 

remove vegetation cover, and the site may be vulnerable 

to erosion in the short term. Soil can be protected by 

methods such as cutting or masticating the trees and 

leaving the slash or chips on the ground. Another factor 

to consider is whether past erosion due to tree dominance 

has changed soil characteristics in ways that will affect 

the success of seeding. For example, has enough topsoil 

been lost to significantly reduce the seedbed for seed 

germination or the rooting zone of seeded species? 

7. What are the dominant plant species currently 

present, and what is the current and future 

potential natural vegetation (PNV) or plant 

association?

•	 Which tree species, sagebrush species or subspecies, 

other shrubs, and perennial grass species are present 

on the site (key 1 and figs. 11–13; if Phase III, look 

for shrub skeletons on the site)?

•	 Is there evidence that pre-settlement trees occupied 

this site in the past (table 1, key 2)?

•	 What are some of the diagnostic perennial grass and 

forb species (fig. 12)?
The Ecological Site

21

Figure 11. Dead bitterbrush and big sagebrush remnants 

can be distinguished by differences in the wood; bitterbrush 

(top) is clear while sagebrush (bottom) has dark brown bands 

perpendicular to the annual growth rings (from Miller and 

others, 2005).

Figure 12. Diagnostic sagebrush community species oriented 

along a general warm-dry to cool-wet gradient (for definitions 

of plant codes see appendix 2). Low sagebrush (ARAR) also 

occurs at high elevations on shallow soils and topographic 

locations that limit available soil moisture. 

Warm-Dry----------------------------------------------------Cool-Wet

(generally low elevation) (generally high elevation)

Sagebrush

ARARLO < ARAR < ARNO < ARTRWY 

< ARTRTR < ARTRVA 

Other Shrubs

TECA < GRSP < PUTR < AMAL < SYMSPP

Perennial Grasses

ACSP12 < ACHY < HECO26 < PSSP5 

< ACTH7 < FIED < BRCA
The Ecological Site

22

Key 1. Common sagebrush species and subspecies 

associated with piñon-juniper woodlands (figs. 13a-k). Key is 

based on persistent leaves and flower stalks. This key is for 

preliminary identification only. Final identification should be 

based on additional taxonomic information. 

1a. Mature shrubs <20 in. tall. 

2a. Flowers early summer, leaves broadly cuneate, 

with deep, well developed lobes, center lobe often 

buck-toothed (wider than space between two outer 

leaves) (fig. 13a) .................. early sagebrush

2b. Center lobe usually not buck-toothed, flowers 

mid-summer to fall

3a. lowering stalks gray pubescent, weakly 

persistent, leaves grayish green, not sticky or 

glandular (figs. 13b-c) .........low sagebrush

3b. Flowering stalks brown to straw colored, 

persisting into the following year, leaves 

usually darker green and sticky glandular 

(figs. 13d-e) .................. black sagebrush

1b. Mature shrubs >20 in. tall.

4a. Plant even topped or flat-crowned, flower 

stalks mostly >1/2 above vegetative shoots, 

leaves wedge shaped and tapered to base 

with straight margins, leaves fluoresce 

bluish white under ultraviolet light 

(figs. 13f-g) ............... mountain big sagebrush

4b. Plant crowns uneven, flower stalks throughout 

the crown, usually <1/2 above crown, does not 

fluoresce bluish under ultraviolet light. 

5a. Plants usually > 3 ft tall, mature 

persistent leaves 4 times as long as 

wide or longer with straight margins 

(figs. 13h-i)............... basin big sagebrush

5b. Plants usually < 3 ft tall, mature persistent 

leaves less than 4 times long as wide, margin 

curves outward giving bell shaped leaves 

(figs. 13j-k)............ Wyoming big sagebrush
The Ecological Site

23

(a) Leaves of early sagebrush

Figure 13. Common sagebrush species and subspecies 

associated with piñon-juniper woodlands.
The Ecological Site

24

(c) Leaves of low sagebrush

Figure 13. Continued.

(b) Crown of low sagebrush
The Ecological Site

25

(d) Crown of black sagebrush

(e) Leaves of black sagebrush

Figure 13. Continued.
The Ecological Site

26

Figure 13. Continued.

(g) Leaves of mountain big sagebrush

(f) Crown of mountain big sagebrush
The Ecological Site

27

(h) Crown of basin big sagebrush

Figure 13. Continued.

(i) Leaves of basin big sagebrush
The Ecological Site

28

Figure 13. Continued.

(j) Crown of Wyoming big sagebrush
The Ecological Site

29

Figure 13. Continued.

(k) Leaves of Wyoming big sagebrush
The Ecological Site

30

Woodland Tree Growth Form

Characteristic Relatively Young Trees Relatively Old Trees

Juniper crown shape Conical with pointed tip Flattened, rounded, or uneven top (figs. 14a, 16a)

Piñon crown shape Conical with pointed to slightly rounded tip Flattened, rounded, or uneven top (figs. 14b, 16b)Juniper branch structure Branches become progressively smaller from 

bottom to top of tree 

In open stands, large branches near the base 

Piñon branch structure Branches become smaller from bottom to top of 

tree, general orientation is vertical

In open stands branches large near base and remain 

relatively large well into the crown, more randomly oriented. 

Dead wood Little dead wood in bole, few dead branches, little 

or no foliose lichen on juniper

Dead branches, bark missing, juniper covered by a 

light green lichen

Juniper bark (figs. 17a-b) Flaky, relatively thin with limited or shallow 

vertical furrows

Thick, fibrous with well-developed vertical furrows

Piñon bark (figs. 17c-d) Relatively thin, flaky, with weak vertical furrows Thicker, more plate-like structure than furrowed

Table 1. Morphological characteristics of post-settlement (<150 years) and pre-settlement (>150 years) woodland trees (figs. 14–17). 
The Ecological Site

31

Woodland Tree Growth Form

Characteristic Relatively Young Trees Relatively Old Trees

Juniper leader growth(figs. 22a-c)

Terminal leader growth in the upper 1⁄4 of the tree, 

usually >2 in. In open stands, leader growth >2 in. from bottom to top

Leader growth in the upper 1⁄4 of the tree usually 

<1 in.

Piñon leader growth(figs. 22d-e)

Leader growth in piñon similar to juniper but not 

directly visible. Must look for bud scale scars to determine length

Leader growth in upper 1⁄4 of the tree usually <2 in.

Table 1. Continued.
The Ecological Site

32

Key 2. Identifying ecological site and estimated fire return interval (FRI).1a. Potentially can grow big sagebrush

2a. Old live trees on the site (>150 years old)

3a. Old-growth tree canopy >20% ................................................woodland .................. FRI > 150 years

3b. Old-growth tree canopy <20% ................................................tree shrub savanna

4a. Old trees on protected microsites* ........................................................................ FRI < 50 years

4b. Old trees scattered but on deeper soils..................................................................... FRI 50-100 years

2b. No live old-growth trees on the site

5a. No large dead wood or stumps on site (>12 in. diameter fluted) ............shrub steppe ............... FRI < 50 years

5b. Large dead wood present on the site

6a. Density >22/acre ............................................................woodland .................. FRI > 150 years

6b. Density <22/acre ............................................................tree shrub savanna 

7a. Relic wood on protected microsites..................................................................... FRI <50 years

7b. Relic wood scattered but on deeper soils............................................................... FRI 50-100 years

1b. Potentially can grow low sagebrush

8a. Black sagebrush (ARNO) 

9a. Old live trees on the site (>150 years old)

10a. Old-growth tree canopy >20% ..........................................woodland .................. FRI > 200 years

10b. Old-growth tree canopy <20% ..........................................tree shrub savanna
The Ecological Site

33

Key 2. Continued.

11a. Old trees on protected microsites*..................................................................... FRI < 100 years

11b. Old trees scattered but on deeper soils ............................................................... FRI 50-300 years

9b. No live old-growth trees on the site

12a. No large dead wood or stumps on site (>12 in. diameter fluted) ...shrub steppe ............... FRI < 100 years12b. Large dead wood present on the site.

13a. Density >22/acre ......................................................woodland .................. FRI > 300 years13b. Density <22/acre.........................................................tree shrub savanna 

14a. Relic wood on protected microsites ............................................................... FRI <100 years

14b. Relic wood scattered but on deeper soils ......................................................... FRI 100-200 years

8b. Low sagebrush (ARAR)

15a. ARAR >12 in. height (go to 2a and 2b)15b. ARAR <12 in. height

16a. No live old-growth or large relic wood .................................low shrubland ............ FRI > 150 years16d. Old live trees or large relic wood (canopy rarely exceeds 20%) ...tree-low shrub savanna... FRI > 150 years

* 4a and 11a. Are old trees growing uniformly or randomly across the site, or do they grow on microsites (microtopography steep, 

convex, rocky, unusual soil and parent material, etc.)?
The Ecological Site

34

8. Are there old-growth trees on the site, and 

where are they growing (figs. 14–17)?

Old-growth trees have a long history on many 

locations in the region and have provided valuable 

wildlife habitat, added structural and biological diversity, 

and can be part of the PNV on many of these landscapes. 

For these reasons, it is important to identify areas 

where old-growth occurs and to carefully consider the 

appropriateness and consequences of any tree removal 

projects that might jeopardize or enhance the integrity 

of these sites. An appropriate action is the thinning of 

younger trees, particularly in adjacent areas, where there 

is a potential for them carrying a stand-replacement 

fire into the old-growth (fig. 14a). Old-growth trees 

are associated with various soils, landforms, and plant 

associations, but typically grow in rock outcrops or 

on steep slopes (fig. 14b) and have soils that are often 

shallow and course in texture. Old-growth juniper can 

occasionally have an understory of deep-rooted perennial 

grasses (fig. 14c), a situation not observed for piñon. 

Old-growth stands commonly grow in areas where 

accumulation of herbaceous fuels is limited, where 

stand-replacement or mixed-severity fires are infrequent, 

and where tree removal results in limited increases in 

understory productivity (fig. 15). 
The Ecological Site

35

Figure 14. Examples of the range of variation in old-growth 

woodland sites.

(a) Utah juniper in a former shrub savanna site that 

has experienced a recent large increase in tree 

density and fuel loads
The Ecological Site

36

(c) An old-growth Utah juniper site in west central Utah

(b) An old-growth site dominated by piñon on a steep, rocky 

south-facing slope

Figure 14. Continued.
The Ecological Site

37

Figure 15. An open old-growth Utah juniper dominated shrub 

savanna in east-central Nevada.

Questions to ask to determine if the site is or was an oldgrowth site:

•	 Are there trees on the site showing old-growth 

characteristics (fig. 16), or are the trees <150 years 

old (table 1)?

•	 Do the soils typically support persistent woodlands, 

or do they have characteristics such as greater depth 

and mollic horizons that developed under a grass or 

grass-shrub dominated vegetation? 

•	 Does tree structure suggest the site is relatively 

stable (limited recruitment), or are younger trees 

in-filling?

•	 Are there large stumps or snags (>18 in. but often > 

24 in. in diameter), often covered with char? 

•	 Are there large logs or branches lying on the site? 
The Ecological Site

38

(a)

Figure 16. (a) Old-growth Utah juniper and (b) singleleaf piñon 

with dead branches and missing bark.
The Ecological Site

39

(b)

Figure 16. Continued.
The Ecological Site

40

(a) (b)

(c) (d)

Figure 17. Bark characteristics of species of woodland trees 

of different ages. (a) At about 100–150 years, juniper bark is thin 

and flaky. (b) At over 300 years, juniper bark is thick and fibrous, 

with well-developed vertical furrows. (c) At about 100 years, 

piñon bark is thin, flaky, with weak vertical furrows. (d) At over 

300 years, piñon bark is thicker, with a more plate-like structure 

than furrowed. 
The Ecological Site

41

9. Is the PNV estimated to be woodland or shrubsteppe, and what is the estimated fire return 

interval?

Key 2 can help identify the potential of the site 

as tree-shrub savanna (fig. 15), old-growth woodland 

(existing, fig. 18, or following disturbance, fig. 19), 

or shrub steppe. The key also gives an estimated fire 

return interval (FRI) for the site. Return intervals in the 

key are meant only as a coarse proxy of the number of 

years between fires prior to Eurasian settlement if other 

documentation is not available. 

Figure 18. Mountain big sagebrush/bluebunch wheatgrass 

plant association with a stand of pre-settlement Utah juniper 

trees growing on shallow soils. 
The Ecological Site

42

Figure 19. Wyoming big sagebrush community with charred 

stumps on shallow to moderately deep soils that indicate a low 

density of trees has occupied the site since prior to the mid1800s. 

10. What is the ecological site? 

Identification of the ecological site identifies a 

site’s ability to produce a distinctive kind and amount of 

vegetation and the interrelationships of that vegetation 

with other ecological sites over the landscape. The 

characteristics of an ecological site are based on its 

associated physiographic, climatic, soil, and water 

features; and on the plant communities comprising its 

various vegetation states. Information on the specific 

ecological site descriptions that are available can be 

accessed at http://esis.sc.egov.usde.gov/ESIS/. 

11. Prior to European settlement, what would 

the potential disturbance regime (frequency, 

intensity, and kinds of disturbance) have 

been, and how would different scenarios of 

this regime influence the historic range of 

vegetation variability on the site?
The Ecological Site

43

The kind and number of years between disturbance 

events, such as fire (refer to key 2), will help determine 

what kind of plant community is most persistent on a site 

(fig. 20). This can provide a baseline to use in gaging 

how much change has occurred. While conditions prior 

to settlement may not be replaceable, or be a viable 

management goal, the future possibilities for a site are 

not independent of the pre-settlement conditions. Years since last fire

Percent composition

120 80 140 60 40 160 200 100

80604020

0

100

Grassland Shrub steppe Woodland

Grasses Shrubs Juniper woodland

Shrubs

Grasses

Trees – High productive site

Trees – Low productive site

Figure 20. Relation of time since fire and the percent composition (dominance) of grasses, shrubs, and trees (from Miller and others, 2007).
The Ecological Site

44

12. How have post-settlement changes in 

vegetation or disturbance affected the 

vegetation and ecological conditions of the 

surrounding landscape? 

For example, in some areas scattered old trees that 

have survived historic fire regimes are currently at risk 

as a result of post-settlement infill of younger trees or 

woodland expansion into sagebrush areas adjacent to 

old-growth patches (fig. 14)

13. What is the potential wildlife habitat value 

under current compared to potentially restored 

conditions? 

Would vegetation on the site and surrounding area 

support sensitive wildlife species (that is sagebrush 

obligates, such as sage grouse, or species seasonally 

dependent, such as mule deer) (fig. 21)? 

•	 Is it important seasonal habitat (that is, key winter, 

nesting, brood rearing habitat that is being lost to 

tree expansion)? 

•	 Would treatment result in improved connectivity 

between other habitats?

•	 What vegetation layers (herb, shrub, tree) should be 

present and in what relative proportion?
The Current State of the Site

45

Part II: The Current State of the Site 

14. Clearly define the perceived problems: What 

are the factors affecting proper ecological 

function?

An important attribute that affects proper ecological 

function is vegetation structure, specifically the amount, 

type, and distribution of plant ground cover. If the site 

is not functional with respect to water and nutrient 

cycles or soil or biotic integrity, physical conditions 

that are connected to the problem need to be identified. 

Site condition should be evaluated to determine if an 

imbalance in plant community composition, a lack of 

structural diversity in the vegetation community, or a 

high proportion of bare ground are contributing factors. 

With the encroachment or increasing density of trees, 

the best way to maintain or restore hydrologic function 

and soil or biotic integrity is to implement treatments 

that reduce tree dominance while ensuring recovery 

Figure 21. Phase II piñon-juniper expansion woodlands 

in a mountain big sagebrush community with a high level of 

structural diversity. 
The Current State of the Site

46

or maintenance of understory vegetation, particularly 

perennial herbaceous species, on the site. Additional 

factors that might be weighed in treatment decisions 

include multiple management objectives (for example, 

wildlife habitat and fuels management), economic costs/

benefits, and social values.

15. What is the stage of woodland succession 

(Phase I, II, or III), and how does this vary 

across the site?

The stage of woodland development can influence 

the type of treatment selected, follow-up treatments 

and management, understory competition, seed pools, 

and vegetation response following management action. 

Patterns of woodland development and understory loss 

are much the same regardless of which species dominate. 

There are three transitional phases of woodland 

development (figs. 22–25 and table 2): 

•	 Phase I – trees are present but shrubs and grasses are 

the dominant vegetation that influence ecological 

processes (hydrologic, nutrient, and energy cycles) 

on the site; 

•	 Phase II – trees are co-dominant with shrubs and 

herbs, and all three vegetation layers influence 

ecological processes on the site;

•	 Phase III – trees are the dominant vegetation and 

the primary plant layer influencing ecological 

processes on the site. Shrubs no longer dominate the 

understory. 

Stand characteristics can be used to classify 

woodland development according to these phases. Early 

indicators of site dominance include shrub canopy 

mortality and reduction of leader growth on tree saplings 

(<10 ft tall). Leader growth patterns are similar for 

western and Utah juniper, but only directly visible for 

piñon when the growth for the year is still in the ‘candle’ 
The Current State of the Site

47

stage (fig. 22). That is, the stem growth for the year 

has been completed, but needle elongation has not. 

Once needle elongation in piñon has been completed, 

it is necessary to locate the bud-scale scars from the 

previous fall’s terminal bud to determine leader growth. 

The number of years between initial tree encroachment 

and stand closure is largely determined by the rate of 

establishment and climate conditions. On most piñonjuniper sites, stands shift from Phase II to III within 100 

years after the first trees establish.

(a) Utah juniper leader growth in Phase I woodlands

Figure 22. Leader growth, particularly for trees <3m tall, is a 

good indicator of competition among trees. Although similar 

patterns exist for juniper and piñon, leader growth is only 

directly visible in the latter when in the ‘candle’ state.
The Current State of the Site

48

(b) Utah juniper leader growth in Phase II woodlands

(c) Utah juniper leader growth in Phase III woodlands

Figure 22. Continued.
The Current State of the Site

49

(d) Single leaf Piñon leader growth in Phase I woodlands

(e) Single leaf piñon leader growth in Phase III woodlands

Figure 22. Continued.
The Current State of the Site

50

Figure 23. Three phases of woodland succession in piñonjuniper woodlands. 

(a) Subordinate – Phase I

A subordinate piñon-juniper site with up-slope woodland 

expansion into mountain big sagebrush. 

(b) Co-Dominant – Phase II 

A co-dominate piñon-juniper, Wyoming big sagebrush site 

with moderately deep soils. 
The Current State of the Site

51

(c) Dominant - Phase III 

A dominant piñon-juniper site with Wyoming big sagebrush 

and moderately deep soils.

(d) Dominant – Phase III 

A dominant piñon-juniper site with Wyoming big sagebrush 

on a south slope with a restrictive soil layer.
The Current State of the Site

52

Figure 24. Conceptual model with estimated time periods form initial woodland establishment (early Phase I) to minimum stocking adequate to reach Phase III with tree growth, and estimated maximum potential for relative abundance and cover for stands developing on sites from high to low productivity (modified for piñon-juniper woodlands from Johnson, D.D. and R.F. Miller, 2006, structure and development of expanding western juniper woodlands as influenced by two topographic variables. Forest Ecology and Management 229:7-15). 
The Current State of the Site

53

Figure 25. Relation between age and tree height across a range of tree dominance on relatively productive piñon-juniper sites: tree height of dominant and co-dominant individuals more than two meters tall can be used as a coarse proxy to estimate stand age (multiply meters by 3.28 to convert to feet). Drier sites may be older. 
The Current State of the Site

54

Phases of Woodland Succession

Characteristics

(post-settlement stands)

Phase I

(early)

Phase II

(mid)

Phase III

(late)

Tree canopy (% of maximum 

potential)

Open, actively 

expanding <20%

Actively expanding 20 

to 50%

Expansion nearly stabilized > 50%

Juniper leader growth 

(dominant trees) (cm/yr)

Terminal >10 

Lateral >10

Terminal >10 

Lateral 5 to >10

Terminal >10 

Lateral <5

Piñon leader growth 

(dominant trees) (cm/yr)

Terminal >10 

Lateral >5

Terminal >8

Lateral 2 <8 

Terminal >5

Lateral <2

Crown lift*

(dominant trees)

Absent Absent Lower limbs dying or dead, usually where tree 

canopy >40% 

Potential juniper berry 

production

Low Moderate to high Low to near absent

Potential piñon seed 

production

Low Moderate to high Low to near absent in expansion woodlands, low 

to moderate in some old-growth

Tree recruitment Active Active Limited

Table 2. Stand characteristics differentiating three transitional phases of woodland succession for most sagebrush associations. 
The Current State of the Site

55

Phases of Woodland Succession

Characteristics

(post-settlement stands)

Phase I

(early)

Phase II

(mid)

Phase III

(late)

Leader growth 

(understory juniper trees) (cm/yr) (figs. 22a-c)

Terminal >10 

Lateral >8

Terminal 5 to 10 

Lateral 2 to 8

Terminal <5 

Lateral <2

Leader growth

(understory piñon trees) (cm/yr) (Figs. 22d-e)

Terminal >10 

Lateral >8

Terminal 3 to 8 

Lateral 2 to 6 

Terminal <4 

Lateral <2

Shrub layer Intact Nearly intact to 

significant thinning

>75% dead

Table 2.*Crown lift is the mortality of lower limbs, usually due to shading by neighboring trees, but also occurs on large, old trees (Figs. 16a-b). 

Continued.
The Current State of the Site

56

16. What is the current herbaceous understory 

composition?

•	 Is the density of tall perennial bunchgrasses adequate 

for restoration, or should the site be seeded?

•	 What are the desirable species, and how abundant 

are they?

•	 Is there evidence of reproductive effort for the 

desirable species?

•	 Are there young, deep-rooted perennial grasses?

•	 Are there threatened or endangered species on the 

site?

•	 Are invasive plant species present, or are seed 

sources near the site? 

Pre-treatment understory composition, especially 

the relative abundance of native perennial grasses 

and forbs, is the primary determinant of the success 

or failure of efforts to restore plant communities by 

removing or thinning the trees. How does the current 

understory composition compare to the desired 

understory composition? Does pre-treatment understory 

composition, particularly for the herbaceous species, 

indicate that the species will survive and that the site 

will recover following a severe natural disturbance or 

proactive treatment? 

Limited research suggests that if at least two 

deep-rooted perennial grasses (that is, needle grasses, 

bluebunch wheatgrass, Idaho fescue) per 1 m2 (10 ft2) 

persist on the site, recovery of understory vegetation 

after treatment is possible, although this is likely to 

vary with soil type, precipitation regime, and method of 

treatment. If perennial grasses and forbs are not present, 

or if existing plants are in such poor condition that they 

are unlikely to survive the treatment, seeding likely will 

be necessary. The presence of an invasive species seed 

source, like cheatgrass, also may increase the need to 

quickly seed the site (fig. 26).
The Current State of the Site

57

17. Is there recruitment of native perennial 

understory species?

•	 Are there different size sagebrush or bitterbrush 

indicating recruitment?

•	 Are there perennial grass and forb seedlings or small, 

young-looking bunches? 

The presence of established seedlings and young 

plants indicates ongoing recruitment of species, while 

presence of healthy, mature, seed-producing plants 

indicates that the potential for seed production still 

persists on the site. If old, decadent, or dying plants are 

common and no signs of active reproduction/recruitment 

are found, species are likely on the decline and the site 

may require restoration. 

Figure 26. Third growing season after a high-severity fire 

in a high-productivity Phase III expansion piñon-juniper 

site. Crown cover in the pre-burn woodland exceeded 80%. 

Loss of deep-rooted perennials on an otherwise productive 

site resulted in cheatgrass and tumble mustard dominance. 
The Current State of the Site

58

18. Are there invasive plant species on or adjacent 

to the site to be treated? 

If undesirable plants, such as non-native weeds, 

are present on the site or present on adjacent sites, 

controlling their establishment and spread is likely to 

be an important part of the management plan. Weed 

invasion is more likely on the relatively warmer and 

drier sites, resulting from lower elevations and southerly 

aspects. Hot fires where woody vegetation is dense also 

will increase the potential of weed invasion (fig. 26). 

Several studies have shown that annual weeds can 

dramatically increase immediately after a tree-removal 

project or wildfire, but can decrease over a period of 

years if an adequate density of native perennials exists 

on the site prior to disturbance. A careful evaluation of 

expected desirable plant response based on the perennial 

grasses and forbs existing on the site prior to treatment, 

along with clear alternative plans in the event that native 

understory recovery does not occur as expected, will 

increase the likelihood of successful restoration. 

19. What is the percentage of dead shrubs on the 

site, and what are the species? 

As expansion woodlands increasingly dominate a 

sagebrush community, the number of suppressed and 

dead shrubs increases. A large number of dead shrubs 

indicates a site that was recently and rapidly dominated 

by trees (fig. 27). 
The Current State of the Site

59

Figure 27. Rapid expansion and growth of piñon-juniper 

has led to bare ground and dead shrub skeletons. With heavy 

crown fuels, this Phase III woodland will burn under severe 

conditions, and introduced annual weeds will dominate the 

site following fire. 

20. What are the fuel characteristics, and what 

types of fire will the site support? 

•	 What type of prescribed fire will the site support, 

and will it burn under moderate conditions, or will it 

require more extreme conditions (fig. 28.)?
The Current State of the Site

60

An assessment of fuel characteristics and their 

contribution to fire potential and behavior and an 

understanding of how natural processes (for example, 

water, nutrient, fire cycles) may be affected by treatment 

or no management action are necessary for selecting 

management treatments. Is herbaceous vegetation in the 

understory providing fine fuels? Does the amount of 

shrubs and small trees in the plant community provide 

sufficient ladder fuels to carry fire into tree canopies? 

Are the trees dominated by juniper, piñon, or a mix of 

the two? Does the site have a closed tree canopy? Are 

there openings in the canopy that may result in a mixedseverity fire with a mosaic fire pattern? Late Phase II, in 

addition to Phase III sites, often have sufficient crown 

cover to carry crown fires throughout the entire site with 

low humidity, high temperatures, and sufficient winds. 

The more piñon trees in the mix, the more potential 

for a crown fire. The bark of piñon can provide its own 

Figure 28. This site lacks both woody and herbaceous 

understory to carry a fire and adequate desirable herbaceous 

species for restoration. This Phase III woodland often burns 

under extreme conditions, with the outcome of introduced 

annual weeds dominating the site following fire (see fig. 26). 
The Current State of the Site

61

ladder fuels and carry the fire into the canopy if the fuels 

in the needle mat catch fire and fuel moistures are low. 

Branching at the base also facilitates fire reaching the 

crown.

Vegetation composition and fuels of the surrounding 

landscape landscape can directly affect fire risk and the 

ability to contain prescribed fire. Very high fuel loads 

adjacent to a site can greatly increase fire risk, and result 

in larger fires than planned.

21. Are there signs of erosion and overland flow? 

What is the current capacity of the site to 

capture, store, and safely release water (derived 

from interpreting indicators of rangeland 

health2

)? What is the incidence of highintensity summer thunderstorms?

Sites with large areas of bare ground, relatively 

fine-textured soils, steeper slopes, and potential for 

high-intensity thundershowers are susceptible to erosion. 

Runoff can move continuously through connected 

inter-canopy zones of bare ground, causing accelerated 

erosion (fig. 29). Soil in bare inter-canopy zones also 

is more susceptible to raindrop impact, soil crusting, 

decreased infiltration, and increased erosion due to lack 

of protection from vegetation. A thick overstory of trees 

also can reduce soil-water-capture and infiltration by 

limiting the amount of precipitation that reaches the 

2

Pellant, M., Shaver, P., Pyke, D., and Herrick. J., 2005, Interpreting 

indicators of rangeland health – version 4: Technical Reference 1734-6. 

U.S. Bureau of Land Management, National Science and Technology 

Center Denver, CO, 122 p. Available online at http://fresc.usgs.gov/

products/papers/1385_Pellant.pdf. 

Swanson, S., Bruce, B., Cleary, R., Dragt, B., Brackley, G., Fults, 

G., Linebaugh, J., McCuin, G., Metscher, V., Perryman, B., Tueller, 

P., Weaver, D., and Wilson, D., 2006, Nevada Rangeland Monitoring 

Handbook, Second Edition: Educational Bulletin 06-03. Available 

online at http://www.unce.unr.edu/publications/files/ag/2006/eb0603.

pdf.
The Current State of the Site

62

ground. Research indicates that when tree dominance is 

reduced and herbaceous cover is increased, runoff and 

soil erosion decrease on sites with relatively fine-textured 

soils. Leaving tree debris on the ground after mechanical 

treatments can intercept runoff and increase infiltration, 

increase soil moisture by reducing evapotranspiration 

and evaporative loss of soil water, and promote nutrient 

cycling. Signs of erosion may include rills, gullies, plant 

pedestals or terracettes, and water movement of large 

amounts of plant litter. Water flow patterns that show 

coalescing rills indicate high erosion potential (fig. 30). 

Figure 29. A Phase III Utah juniper site with large areas of 

bare ground potentially susceptible to accelerated runoff and 

erosion.
The Current State of the Site

63

22. What is the current wildlife habitat suitability, 

and what species are involved? How will 

treatment affect wildlife species? 

Habitat suitability will largely be determined 

by the composition and structure of vegetation at the 

community and landscape level. The spatial arrangement 

and connectedness of plant community patches are 

important attributes in determining habitat suitability.

Figure 30. A piñon-juniper site with large, connected zones of 

bare ground and water flow patterns in the inter-canopy.
The Current State of the Site

64

Increasing tree dominance at the community and 

landscape levels results in a decline in landscape and 

plant community diversity, which reduces wildlife 

abundance and diversity. Research has not identified any 

wildlife species that are obligates to closed (Phase III) 

woodlands. However, old-growth and open woodlands 

can provide important habitat especially for cavity 

nesters. Some habitat suitability conditions to consider 

when planning treatments are: 

•	 Is the site in a transitional phase that will alter 

structure and composition, resulting in a change in 

habitat suitability?

•	 Juniper berries (female cones) can be an important 

winter food source for a variety of birds. Piñon nuts 

also are an important food source for many small 

mammal and bird species, particularly the Piñon Jay 

and Clark’s Nutcracker. Maintaining a woodland 

component on sites where these species are present 

can be beneficial. However, as woodlands transition 

toward Phase III, juniper berry and pine nut 

production declines. 

•	 Bird species diversity and richness are greatest 

in Phase I and early Phase II, when understory 

vegetation is still intact because these phases provide 

important structural diversity. 

•	 Greater numbers of tree cavity-nesting birds are 

usually found in old-growth woodlands (fig. 31). 

•	 Mule deer and elk use tree stands as winter cover. 

Dense stands with trees more than 5 ft tall provide 

optimal thermal cover but minimal food resources 

if dense stands are present across large areas of the 

landscape. 

•	 Decreased shrub cover due to woodland development 

and tree dominance results in decreased browse 

available for deer, elk, and other species. 

•	 Decreases in grasses reduce seed production and 

seeds eaten by small mammals and birds. 
The Current State of the Site

65

23. Are there social or economic concerns and 

issues tied to the site?

Treatment of a site may not be feasible or practical 

due to ecological, economic, or sociological reasons. 

Treatment can be expensive, especially for Phase III 

woodlands, because of inputs needed to return the site 

to a desired condition, and achieving desired results can 

be difficult. Because Phase III woodlands are increasing 

in area, the potential for wildfires of increased intensity 

and severity is greater. Following wildfires, these sites 

will require expensive treatment to prevent dominance by 

cheatgrass and other exotic species (fig. 26). 

Figure 31. Tree cavity in the trunk of an oldgrowth singleleaf piñon. Old stands of trees 

have a relatively high density of cavity nesting 

birds. 
The Current State of the Site

66

Conducting an economic evaluation of the options 

may assist a manager in considering the long-term 

environmental consequences. Not all benefits and costs 

involved with these treatments are quantifiable or have 

dollar values attached to them. This also applies to 

the long-term costs/benefits of not treating a site. In 

such cases, a social costs/benefit analysis can be used 

to identify both the quantifiable and non-quantifiable 

benefits and costs. Where dollar values cannot be 

determined, other economic principles may need to be 

determined to assist in allocating resources, such as 

treatment funds and labor. 

Treating a stand in Phase I may make more 

economic sense than waiting until mid Phase II or 

beyond even though the apparent immediate benefits 

may be lower. Regardless of phase, seeding can be more 

risky on dry sites, where a high amount of erosion has 

occurred, where safe sites are not plentiful for seedling 

establishment, or where non-native invasive species 

are likely to quickly occupy the site. Tree removal 

on sites where any treatment is not likely to succeed 

may cause greater ecological damage (for example, 

increased bare ground, erosion and nutrient loss, 

increased weed invasion, and loss of wildlife habitat) 

than no management action. The potential increase in 

fire intensity and size with a continual increase in tree 

dominance also may need to be considered. 

Social issues to consider include wildland-urban 

interface values, perceived ecological impacts of 

different treatments, concerns for sensitive wildlife and 

plant species, recreation, development, archeological 

sites, etc. 
Landscape Considerations

67

Part III: Landscape Considerations

24. What are the spatial landscape characteristics 

of the area to be treated with respect 

to topography, patch3

 size, edge, and 

connectedness? 

Patch Size: Treatment patch size is especially 

important to consider in relation to use by wildlife and 

livestock. Is the treatment size large enough to provide 

suitable conditions for wildlife species of concern? Is 

the treatment area so small that post-treatment overuse/

overgrazing by domestic or wild herbivores will threaten 

the survival of newly established understory plants 

or aspen? Even with adequate forage in the area, the 

palatability of plants for several seasons after a fire will 

be higher than before, and burned patches will tend to 

attract wild and domestic herbivores. Is the patch size 

large enough to justify post-treatment management 

changes, such as no grazing for 1 or 2 years before or 

after the burn? If the treatment site is a relatively small 

area within a much larger pasture, resting the entire 

pasture from grazing may not be economically feasible 

or socially acceptable. Doing so may result in more 

ecological harm at other sites as grazing pressure is 

moved to those locations on either public or private land. 

Fencing a smaller treated area may be a viable option. 

3

A patch is defined here as an assemblage of plant species growing 

on a contiguous area forming a plant community with a defined 

boundary and possibly representing different successional stages within 

an ecological site.
Landscape Considerations

68

Edge: When needed, will treatment shape and 

layout create sufficient edge habitat that is valuable 

to wildlife? What treatment procedures will be used 

to result in sufficient edge habitat that is valuable to 

wildlife? How will the spatial distribution of edge 

influence seed rain from adjacent unburned sites onto 

the treated site? Feathering the edge can result in a more 

natural-looking appearance, as well as providing for 

more edge habitat. 

Connectivity: Is the connectivity of various 

patches across the landscape important for wildlife 

species of concern? Patch topographic relationships 

and connectivity can influence wildlife movement, 

recruitment, predation, etc. Distance to similar patches 

or patches of concern and the vegetation conditions in 

between are part of a complex interaction of variables 

that influence connectivity for different wildlife species. 

Because they affect wildlife movement, recruitment, 

predation, etc., they need to be considered. 

25. What is the composition of adjacent patches, 

what is their landscape distribution of 

vegetation patches, and what are their stages of 

woodland succession?

After considering how the site is connected to, or 

isolated from other patches and the distance to similar 

patches, will the treatment enhance wildlife habitat 

and watershed health? Do corridors exist between 

suitable habitat patches for wildlife movement? Does 

the composition of patches across the landscape provide 

diverse habitat for a variety of wildlife in all seasons? 

How will treatment affect biodiversity at the landscape 

level? 
Landscape Considerations

69

26. What is the current variation in understory 

composition and in the recruitment of native 

understory species over the surrounding 

landscape? 

The usefulness of treatment for a particular site 

can be influenced by the understory composition and 

recruitment present on the landscape around the site. 

Treatment of a site surrounded by Phase I and early 

Phase II woodlands, for example, can do more to 

enhance wildlife habitat than if it is surrounded by late 

Phase II or Phase III woodlands that may limit wildlife 

access and increase the risk of damage from adjacent 

crown fire. 

27. How do fuel characteristics of tree, shrub, and 

herbaceous layers vary over the surrounding 

landscape, what type of fires are they likely to 

support, and how might this influence the types 

of fire possible on the site? 

The fuel load characteristics on the landscape 

around the site of concern can, and in many 

circumstances will, override the fuel load characteristics 

of the site. This can result in types of fires that might not 

otherwise occur on the site, particularly wildfire. 

28. Are there signs of erosion and overland flow 

from the surrounding landscape that suggest 

impacts to the site?

Watershed characteristics of the surrounding 

landscape, particularly up slope of the site, may have 

more to do with erosion occurring on the site than the 

conditions on the site. 
Landscape Considerations

70

29. Will the conditions of the surrounding area 

influence the wildlife habitat suitability of the 

site, or affect the species involved? 

Landscapes are composed of patches of different 

topographic sites, plant communities, and habitats. 

Management of landscapes rather than just individual 

stands includes consideration of patch composition, 

topographic and spatial arrangement, size, and 

connectivity. Consideration of which patches and 

how much to treat are important. Portions of these 

landscapes may provide key habitat for certain species 

(that is, sagebrush cover for sagebrush obligates or deer 

fawning). The initial removal of sagebrush as trees are 

removed may be necessary to maintain the long-term 

integrity of these important habitats. An alternative 

would be to treat a percentage of these key habitats, 

saving the remaining proportion for treatment at a later 

date when the treated areas have recovered. Maintaining 

a mosaic of patches of different successional stages 

also may be desirable for maximizing habitat diversity, 

reducing fuel continuity, increasing snow capture, etc. 

30. What are current uses, management activities, 

and social and economic concerns for the 

surrounding landscape that might affect the 

site?

It is important to consider how a treatment will 

affect current use and management activities in the short 

and long term. If the immediate treatment negatively 

affects wildlife habitat or livestock grazing, how long 

will it take to realize benefits of treatment? Are there 

other areas available for these uses during the short 

term? If the treatment location is within a larger area 

that is being managed for other purposes such as fuels 

reduction, how will the treatment affect, and be affected 

by this management? 
Selecting Appropriate Management Action and Treatment

71

Part IV: Selecting Appropriate 

Management Actions and Treatments 

Woodland structure within and across successional 

phases, in addition to age, is largely determined by the 

type, frequency, and intensity of disturbance, especially 

wildfire. The most ideal management actions will 

be determined by considering the composition of all 

vegetation layers of the communities involved, economic 

feasibility, and social acceptability. 

31. What are the factors that will influence 

selection of preventive, maintenance, or 

restoration treatments, including personnel 

available, grazing schedules, and wildfire risk? 

1. Pre-treatment fuel composition, loading, and 

structure

•	 Tree sizes

•	 Number of trees per acre

•	 Dead plant material

•	 Herbaceous plant composition, size, and 

density

•	 Shrub composition, size, and density

2. Plant composition

•	 Abundance of desirable species

•	 Desirable fire-sensitive species (for example, 

sagebrush, bitterbrush)

•	 Invasive species

•	 Woodland phase

3. Ecological site, soils, and topography
Selecting Appropriate Management Action and Treatment

72

4. Species of concern (for example, sage grouse)

5. Objectives

6. Size of area to be treated

7. Legal liabilities and risks from proximity to other 

plant communities (for example, forest)

8. Cost and resources

9. Social acceptability

All nine factors also can be easily modified for use 

in the determination of post-fire management response. 

32. What are treatment options, including 

mechanical, prescribed fire, cut and burn 

combinations, chemical applications, and 

seeding? 

Mechanical Treatments

Mechanical treatments are often used to reduce tree 

dominance in Phases II and III woodlands. However, 

they make seedbed preparation and sowing difficult 

when the site requires revegetation. In general, the 

advantages of mechanical removal of trees include 

flexibility in timing of treatment application and the 

ability to precisely control treatment boundaries or 

targeted trees. For example, old-growth trees can be 

left as wildlife habitat. With mechanical treatments, the 

impact to understory vegetation is often minimal. Cut 

trees, slash, or chips also can be left on site to control 

erosion and provide safe sites for seedling establishment 

or to enhance wildlife habitat. Although Utah juniper is 

non-sprouting, the lower most limbs and green buds at 

the base must be removed to kill the tree (fig. 32). 
Selecting Appropriate Management Action and Treatment

73

Figure 32. Example of juniper resprouting after chainsaw 

cutting left a lower limb. 

Disadvantages are that mechanical methods often 

require follow-up treatment for small trees not initially 

removed, fuel loads can be increased by leaving cut 

trees/slash on the site, and treatment can be difficult to 

implement and costly when working in areas with rough 

terrain. Large amounts of slash in late Phase II and 

Phase III create a fire hazard for a minimum of 2 years 

and can limit the mobility of large herbivores (domestic 

and wild). Heavy slash, which may kill desirable plants 

by shading, will provide open sites for establishment 

of introduced species. It also may alter site nutrient 

relations. 

Patience may be required in regards to treatment 

response when using mechanical treatments for 

restoration. A delayed understory response is common. 

Understory response in the first year after treatment 

is unpredictable, and it may take several years for 

understory plants to fully occupy the treated area. 
Selecting Appropriate Management Action and Treatment

74

Heavy machinery: Heavy machinery can be used 

to reduce tree dominance, but these treatments tend 

to be expensive and should not be used when soils are 

excessively wet. Methods include using bulldozers 

to push trees over, chaining with bulldozers that pull 

anchor chains or steel cables to uproot trees, or the use 

of mechanical cutting and grinding devices such as the 

Bull HogTM (fig. 33). Chaining can occur in one or two 

(opposite) directions, usually with seeding occurring 

between the two directions. When it fits project goals 

and is economically possible, removal of the downed 

trees can reduce fuel loads.

Figure 33. An example of tree mastication (bullhogging) on a 

juniper-dominated site in western Utah. 
Selecting Appropriate Management Action and Treatment

75

Soil conditions, such as texture and moisture 

content, and machinery operation (for example, use 

of tight turns) should be evaluated, and factored into 

plans in order to minimize soil compaction and surface 

disturbance, such as avoiding times when soil-water 

content is high. Impacts on desirable understory 

vegetation also may be a concern with use of heavy 

machinery, but effects are often light to moderate with 

chaining. While, chaining has not been used in western 

juniper woodlands since the 1980s, it is still occasionally 

being used in piñon-juniper woodlands in Nevada, and 

in Utah after a fire. When not following a fire, chaining 

often requires a follow-up treatment, such as fire, to 

eliminate saplings and sustain the life of the treatment. 

Mastication treatments such as bullhogging are 

increasingly being used in Nevada and Utah. The shortand long-term ecological effects of these treatments are 

under study.

Feller bunchers cut and lay groups of 3–8 trees 

(depending on size) on the ground. Bundles can be left 

in place, burned, or chipped. However, little is known 

about the ecological effects of burning piles or leaving 

chips on site. Soil surface disturbance from feller 

bunchers is usually minimal on dry soils. Depending on 

the price being paid for chips and the distance they must 

be hauled, biomass utilization can significantly offset, 

if not pay for, the cost of tree removal. For more remote 

areas in which piñon-juniper woodlands are often found, 

transportation costs can make hauling the wood chips 

prohibitive.

Chainsaw cutting: Chainsaw cutting selectively 

kills trees with minimal soil disturbance (fig. 34). 

Costs increase when treating areas with steep terrain 

or areas where use of heavy machinery is not feasible. 

Cutting may be the only treatment option in areas of 
Selecting Appropriate Management Action and Treatment

76

(a) On a juniper-dominated site in western Utah.

cultural resource concern. Expense of cutting treatments 

increases when limbs or slash are spread across the site, 

so this should only be done where post-treatment erosion 

is a risk. Smaller areas can often be more economically 

treated by opening them to the public for firewood 

cutting. This treatment will maintain and usually increase 

stand vigor of non-sprouting understory shrubs like 

sagebrush. However, cutting that leaves debris in place 

may increase the risk of fire. 

Figure 34. Piñon-juniper chainsaw cutting in woodlands.
Selecting Appropriate Management Action and Treatment

77

(b) One year after chainsaw cutting on a piñon-juniper, 

Wyoming sagebrush site in eastern Nevada.

Figure 34. Continued.

(c) Second growing season after chainsaw cutting on a piñonjuniper, Wyoming sagebrush site with Phase II woodlands.
Selecting Appropriate Management Action and Treatment

78

Figure 34. Continued.

(d) Second growing season after chainsaw cutting on a 

piñon-juniper, Wyoming sagebrush site with early Phase III 

woodlands. 
Selecting Appropriate Management Action and Treatment

79

Prescribed Fire: Prescribed fire is often the most 

economical way of treating larger landscape areas, 

particularly when woodlands are in Phase I or early 

Phase II. The primary factors that will influence postburn response to fire are:

•	 Plant community composition

•	 The presence or absence of perennial grasses, forbs, 

and seed pools prior to treatment 

•	 Ecological site (site potential)

•	 Extent and patchiness of fire

•	 Climatic conditions before, during, and after the 

fire, which can increase stand vigor of non-sprouting 

shrubs like sagebrush. However, cutting that leaves 

debris in place may increase the risk of fire. 

Prescribed fire treatments can produce desirable 

results on sites with woodlands in Phases I and II 

particularly when there is an abundance of perennial 

natives in the understory (>2 desirable grasses/m

2

) (figs. 

35a-b). On sites that are in late Phase II or Phase III and 

have a depleted understory, (1) fire may be difficult to 

carry through the stand as a result of limited ground and 

ladder fuels, (2) treatment may be more costly due to the 

need for higher inputs (see cutting and burning), and (3) 

site response less predictable with potential for success 

lower (for example, more annuals versus perennials in 

the response compared to treating sites in earlier states 

of woodland succession). Where tree dominance is high 

and woodlands are contiguous, crown fires can rapidly 

cover large areas. When piñon dominates, their bark 

can easily carry fire into the crown. When weeds, such 

as cheatgrass, are present on the site, risk of failure is 

increased, especially if the site is warm and dry, or where 

soils are shallow or fine-textured. Additional follow-up 

treatments to reduce undesirable species and seed 

herbaceous perennials can be beneficial. 
Selecting Appropriate Management Action and Treatment

80

Figure 35. Understory responses 2 years after prescribed 

fire in Phases (a) I, (b) II, and (c) III piñon-juniper dominated 

Wyoming big sagebrush communities in eastern Nevada. 

(a)

(b)
Selecting Appropriate Management Action and Treatment

81

An initial response to either prescribed fire or 

wildfire includes decreased litter and woody vegetation 

and increased bare ground. How will these responses 

affect wildlife (that is, loss of the shrub layer), water 

runoff, and erosion in the short term? Mountain big 

sagebrush usually will recover to pre-burn levels within 

25 to 35 years (varies with climate and seed source). 

Recovery in Wyoming big sagebrush areas is usually 

slower, but not always (fig. 36). Controlling the 

temperature and duration of prescribed fire, primarily 

where 100 and 1,000 hour fuels are heavy, is important 

for protection of the soil and understory vegetation. This 

may be achieved by fuel preparation so the fire treatment 

can be applied under more mild weather conditions. Sites 

that have a greater incidence of summer thunderstorms, 

finer textured soils, and steeper slopes have the highest 

soil erosion potential. Hydrophobicity can be a problem 

directly beneath the tree canopy resulting in limited 

seedling establishment and increased soil erosion. 

Figure 35. Continued.

(c)
Selecting Appropriate Management Action and Treatment

82

Burning in Aspen for Juniper and Piñon Removal

Due to high fuel-moisture conditions often found 

in aspen forests, prescribed fire can be difficult to 

implement. However, if suitable conditions (for example, 

fuel preparation – see ‘Prescribed Fire’ on p. 78) exist 

for fire, burning can produce desirable results. Protection 

from livestock and wildlife use may be necessary for 

aspen establishment after treatment. Research indicates 

this could take about 3 to 5 years to allow the terminal 

buds to grow above the browse line, but depends on site 

conditions and climate. 

Cut and Burn Combinations: A combination of 

cutting and then burning is used to (1) increase ground 

fuels to carry fire or (2) remove tree slash created by 

cutting. This treatment combination is most often 

used in late Phase II and Phase III. Late summer or 

Figure 36. Thirty-five-year-old north-slope wildfire that burned 

through Phase III expansion piñon-juniper woodlands (still 

present in the background). It is now dominated by Wyoming 

big sagebrush with green rabbitbrush and green ephedra 

sub-dominant. 
Selecting Appropriate Management Action and Treatment

83

fall burning in Phase III can have severe effects on 

understory vegetation resulting in >75% mortality. Late 

fall or winter burning (late Sept.–Mar.) has less-severe 

effects resulting in 20–50% mortality of the remaining 

perennial grasses. Cut and burn treatment of Phase 

III stands is higher risk and more expensive than in 

Phases I and II. Cutting no more trees than necessary is 

recommended to keep the treatment as cost-effective as 

possible and to avoid building a fuel load that will result 

in a fire that is too hot. Other precautions noted earlier 

regarding understory vegetation, erosion, wildlife habitat, 

economic feasibility, and social acceptability on Phase 

III woodlands need to be considered. 

Research on social acceptability of vegetation 

management in rangelands has found that citizens 

generally prefer prescribed fire as a treatment because 

it is perceived as more “natural” than other treatments. 

However, preference is maintained only insofar as smoke 

levels and risks of adjacent property damage are low; in 

locations near human habitation, mechanical treatment 

may be more acceptable to the public. All other things 

being equal, citizens are likely to prefer chainsaw cutting 

over the use of bulldozers. No published research has 

examined the relatively acceptability of cutting and 

grinding machines (that is, bullhogging)

4

.

Chemical Treatments

Because past chemical application on piñon and 

juniper, particularly western juniper, has met with poor 

or mixed results, only limited information is available 

to guide managers in using this method. The most 

important consideration for chemical treatment of 

woodlands is site selection. Chemical treatment should 

only be used on sites where the herbicide will work as 

intended (for example where the soil type, especially 4

Brunson, M.W., and Shindler, B.A., 2004, Geographic variation in 

social acceptability of wildland fuels management in the western U.S.: 

Society and Natural Resources, v. 17, p. 661-678.
Selecting Appropriate Management Action and Treatment

84

high clay content, will not interfere with the chemical’s 

performance) and the understory has potential to 

respond. Following herbicide treatment, standing trees 

may interfere with subsequent weed control and seeding 

of perennials. Social acceptability tends to be lower 

for chemical treatments than for any other restoration 

method. 

Tebuthiuron and Picloram: Aerial application 

of pelleted tebuthiuron and picloram has been the 

most effective way of chemically controlling Utah 

juniper and piñon. Understory species tend to recover 

faster from picloram than tebuthiuron applications. 

Rates of up to 1.1 kb active ingredient/ha have been 

effective. Applicators should carefully follow label 

recommendations. High rates are more effective on more 

clayey or deep soils, while lower rates may be effective 

on shallow soils near ridge tops. 

Other Chemicals: Velpar L. Pronone Power Pellets, 

Chopper and Arsenal treatments have been shown to 

be effective in northern California for juniper trees as 

tall as 6 ft. Chopper and Arsenal also have shown to be 

effective for treating cut juniper stumps with green limbs 

remaining below the cut. 

Seeding

Success of seeding on treated sites to reduce tree 

dominance is greatly influenced by effective precipitation 

and soil texture. Because tree stumps typically remain 

following fire and downed trees or slash are present after 

mechanical treatments, broadcast seeding is often used. 

Methods that provide for good seed/soil contact should 

be used if possible. Seeding without some provision 

for seed coverage has only been successful for years or 

sites with high precipitation. Drill seeding is preferable 

in Phase I and low density Phase II stages or broadcast 

seeding followed by dragging a chain across the surface. 
Selecting Appropriate Management Action and Treatment

85

Establishment of introduced and native grasses has been 

more consistently successful than that of native forbs or 

shrubs. Establishment of big sagebrush is inconsistent 

but may be enhanced by dropping seeds and pressing 

them into the soil surface with a packer wheel on a 

specialized drill or by aerial seeding on snow. Please see 

“restoring western ranges and wildlands” for detailed 

seeding recommendations (http://www.fs.fed.us/rm/pubs/

rmrs_gtr136.html) (figs. 37 and 38). 

Figure 37. Moderate-severity fire (notice needles on trees) 

where 80% of the native species in the understory survived; no 

seeding is required. 
Selecting Appropriate Management Action and Treatment

86

Figure 38. Examples of high-severity fire (notice no needles 

or bark remain on trees) where mortality of native herbaceous 

species was >80%. (a) One year after a western Utah fire, the 

site is dominated by introduced annual and biannual weeds; 

seeding required to reduce the spread of invasives. (b) One 

year after a fire in a dense Phase III expansion piñon-juniper 

site. Fire severity was such that only a few green plants are 

visible, most of them exotic annuals. Without seeding, the risk 

of dominance by exotic annuals is high. 

(a)

(b)
Selecting Appropriate Management Action and Treatment

87

33. How will post-treatment management, 

including the need for maintenance on the site, 

and on the surrounding landscape affect site 

conditions and function? 

Maintenance of desirable site conditions is most 

likely when post-treatment management remains 

adaptive and flexible, and when plans are continually 

reassessed. An optimal management approach 

considers short- and long-term successional responses 

and evaluates the benefits of maintenance of the site 

with follow-up treatments. A good post-treatment 

monitoring plan should be implemented. At a minimum, 

photographs should be taken at established points on a 

regular basis and cover of the dominant species should 

be assessed across the project area. More detailed 

monitoring may be necessary in areas where negative 

hydrologic responses or invasive species are potentially a 

problem. Changes in the condition of the landscape area 

adjacent to the treated site should also be noted.

How will treatment influence the distribution 

of livestock and wildlife use of the site? Rest from 

grazing following treatment will significantly improve 

the likelihood of success, especially if the understory 

is depleted. If it is not possible to keep animals out of 

the treated area, grazing impacts can be reduced by 

controlling placement of water and mineral supplements 

or grazing when herbaceous species are dormant in late 

summer and fall. This may also require the limitation 

or postponement of grazing in the surrounding area. 

After fire, 2 years of rest from grazing is a common 

practice, but plant response is often a better indicator of 

the actual amount of rest needed. In more arid areas or 

in areas in poor ecological condition prior to treatment, 

complete deferment and longer rest periods may be 

necessary. Grazing during the growing season in the first 

and second years following treatment has been shown to 

increase mortality and decrease leaf and seed production 

of desirable grasses. It also has been shown to increase 
Selecting Appropriate Management Action and Treatment

88

the establishment and reproduction of invasive species 

like cheatgrass. Grazing after seed set in the first 2 years 

following treatment has been shown to have lesser effects 

on plant health. However, maximizing seed production 

and seedling establishment after treatment is important, 

and production of grass and forb seed is not likely to 

be significant until the second year post-fire. Usually, 

cutting and chemical applications minimally affect 

understory vegetation, but heavy equipment or highseverity fire may have greater impact. 
Appendix

89

Appendix 1: Field Assessment Form

Site Name _____________________________________

Location ______________________________________

Date__________________________________________

I. Ecological Site / Plant Association

A. Diagnostic sagebrush species___________________

B. Bitterbrush present? Y / N

C. Diagnostic perennial grass(es) __________________

D. Old growth on the site (table 1)? Y / N

E. Large wood found on the site? Y / N

F. Plant association or PNV ______________________

G. Ecological Site ______________________________

a. Soil Type ______________________________

H. Historic fire return interval (key 2) ______________

I. Soil erosion potential High Moderate Low

J. Species of concern ___________________________

II. Current State

A. Dominant shrub ______________ recruitment. Y / N

B. Desirable shrub ______________ recruitment. Y / N

a. % dead <10% 11-25% 26-50% >50%

C. Dominant grass(es) __________________________

a.	 ≥2 desirable grasses/m2? Y / N

D. Post-settlement trees present? Y / N; Phase I II III

E. Invasive species present? Y / N

F. Evidence of surface erosion (rills, sediment dams,

pedestals, etc.)? Y / N

G. Current plant community ______________________
Appendix

90

H. Perceived problem ___________________________

I. Habitat suitability for target species 

Low Moderate High

a. If low or moderate, what is missing?_________

J. The site will burn With / Without pre-treatment.

K. Social concerns _____________________________

L. Current uses ________________________________

III. Landscape considerations

A. Size of area to be treated ______________________

B. How will treatment affect adjacent patches? _______

C. Treatment will fragment / link adjacent patches.

IV. Management Action

Phase I and/or II (circle treatment recommendation)

A. Cut

B. Burn

C. Seeding required Y / N 

D. Other options _______________________________

Phases II and/or III (circle treatment recommendation)

A. Partial cut and broadcast burn

B. Cut drop and leave

C. Cut drop and burn

D. Cut pile and burn

E. Seeding required Y / N 

F. Other options _______________________________

Considerations

A. Small trees may require follow-up

B. Weed potential, shrub layer, liability, structures, 

containment

C. Post treatment

D. Monitoring
Appendix

91

Species Codes

Code Scientific Name Common Name

AMAL Amelanchier alnifolia ServiceberryARAR Artemisia arbuscula Low sagebrushARARLO Artemisia arbuscula longiloba Early sagebrushARNO Artemisia nova Black sagebrushARTRWY Artemisia tridentata ssp. whyomingensis Wyoming big sagebrushAFTRTR Artemisia tridentata ssp. tridentata Basin big sagebrushARTRVA Artemisia tridentata ssp. vaseyana Mountain big sagebrushBRCA Bromus carinatus Mountain bromeGRSP Grayia spinosa Spiny hopsagePUTR Purshia tridentata BitterbrushSYM Symphoricarpos species Snowberry

TECA Tetradymia canescens Spineless or gray horse-brush

ACNE Achnatherum nelsonii Colombia needlegrass

ACTH7 Achnatherum thurberiana Thurber’s needlegrassACHY Achnatherum hymenoides Indian ricegrassACSP12 Achnatherum speciosa Desert needlegrassFEID Festuca idahoensis Idaho fescueHECO26 Hesperostipa comato Needle and threadPSSP5 Psuedorogneria spicata Bluebunch wheatgrass

Appendix 2: Species Codes
Glossary

92

Glossary of Terms

Bare ground: exposed mineral soil that is susceptible 

to raindrop splash erosion. The size, distribution, and 

connectedness of bare ground are the most important 

contributors to site stability relative to site potential.

Cover type: see potential natural vegetation.

Ecological site: a type of land with specific physical 

characteristics that differs from other types of land in 

its ability to produce distinctive kinds and amounts of 

vegetation and its response to management. Apparently 

synonymous with ecological type used by USDA 

Forest Service, and Rangeland Ecological Site (http://

esis.sc.egov.usda.gov/Welcome/pgReportLocation.

aspx?type=ESD).

Ecological function: referred to here as the actions 

or behavior of important processes such as hydrology, 

nutrient cycling, and energy capture.

Fire Return Interval (FRI) (or fire free interval or 

return fire interval): the number of years between two 

successive fires documented in a designated area (that 

is, the interval between two successive fire occurrences); 

the size of the area must be clearly specified. Variability 

in intervals is the meaningful reality of the disturbance 

regime on the site, not the mean (MFRI).

Fluted: pockets where the cambium layer folds in on 

itself forming deep grooves or bark pockets.

Fuel: all burnable material live and dead.

Functional goals: examples are watershed health, 

habitat for a defined set of species, etc., which are met by 

a desired set of conditions on the site often determined 

by vegetation composition and structure. 

Gullies: channels that have been cut into the soil by 

moving water.
Glossary

93

Ladder fuel: material on or near the ground that will 

carry fire from the ground to the crown of trees (that is, 

sagebrush, bitterbrush, dead down wood and branches).

Management unit: an area of land defined by boundaries 

where a management strategy is to be applied. The land 

area may be composed of one or more ecological sites, 

and the entire area may or may not be treated.

Mean Fire Return Interval (MFRI) (or mean fire 

free interval): arithmetic average of all fire intervals 

determined in a designated area during a designated time 

period; the size of the area and the time period must be 

specified. MFRI only provides the central tendency; 

variability in intervals is the meaningful reality of the 

disturbance regime on the site, not the mean (MFRI). 

Post-settlement trees: trees establishing after 1860.

Potential natural vegetation (PNV): the vegetation that 

will persist under the pre-settlement disturbance regimes 

and climate. PNV is an expression of environmental 

factors such as topography, soils and climate across 

an area where cover type is a classification of existing 

vegetation. The existing cover type at any particular 

location and time may reflect a vegetation community 

anywhere along its successional pathway—from seral to 

climax.

Pre-settlement: trees establishing before 1860 (see oldgrowth). 

Old-growth: a relative term that has been based on 

morphological characteristics, actual age, or general 

period of establishment (pre- and post-settlement, before 

or after 1860).

Rills: small, erosional rivulets that are generally linear 

and do not necessarily follow the microtopography that 

flow patterns do.

Savanna or savannah: grassland or shrub-steppe with 

widely scattered trees (<10% canopy cover).
Glossary

94

Soil/site stability: capacity of an area to limit 

redistribution and loss of soil resources including 

nutrients and organic matter by wind and water 

(Pellant, M., Shaver, P., Pyke, D.A., Herrick, J.E. 2005. 

Interpreting the indicators of rangeland health (version 

4). BLM Technical Reference 1734-6. United States 

Department of the Interior, Bureau of Land Management 

National Science and Technology Center, Denver CO. 

122 p.).

Species of concern: species that require special 

consideration in restoration. These include species 

that may increase following treatment (that is, noxious 

weeds) or species that are declining or appear to be in 

need of concentrated conservation actions, including 

State Endangered, State Threatened, State Sensitive, or 

State Candidate species.

Stocking: fully stocked site is one with enough trees 

that does or will eventually fully occupy a site (that is, at 

maturity, interspecific competition limits the expansion 

or addition of new leaf canopy). Stocking density varies 

across ecological sites and with tree size.

Water flow pattern: the path that water takes as it 

moves across the soil surface during overland flow. 

Evidence of water flow patterns include redistribution 

of litter, soil or gravel, or pedestalling of vegetation or 

stones.

Woodland: an area of smaller statured trees usually with 

canopy cover >10%; open 10-20%, intermediate 20-40%, 

dense >40%.
Glossary

95

Abbreviation Definition

in. inches

ft feet/foot

m meter(s)

cm centimeter(s)

mm millimeter(s)

ha hectare

% percent

yr(s) year(s)

Abbreviations
Glossary

96

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For more information concerning the research in this report, contact the 

Communications and Information Management Program, 

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U.S. Geological Survey, 777 NW 9th Street 

Corvallis, Oregon 97330

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http://fresc.usgs.gov
Tausch and others—Piñon and Juniper Field Guide: Asking the Right Questions to Select Appropriate Management Actions— Circular 1335