Forest Health Monitoring

in the Interior West

A baseline summary of forest issues, 1996–1999

United States

Department

of Agriculture

Forest Service

Rocky Mountain

Research Station

General Technical

Report RMRS-GTR-75

May 2001
Research Summary

Although forest health may be difficult to define and measure, a strong demand exists for assessment of forest conditions at various state, regional, and national scales. Forest Health Monitoring (FHM)

is a national program designed to measure the status, changes, and trends of forest conditions annually.

This report presents a broad view of forest health issues affecting the Interior West region of Montana,

Idaho, Wyoming, Utah, Nevada, Colorado, New Mexico, and Arizona. We found that the forests of the

Interior West have changed considerably in the past century. What is more difficult to assess is whether

humans have promoted change that is irreversible, or whether the change we see in the forested landscape

is within healthy bounds. Discussions of forest health and forest cover change, the developed and

wildland interface, insect and disease disturbances, watershed health, biodiversity, and air quality

comprise the body of this report.

 This initial report sets the stage for more in-depth reports on forest health in the Interior West by

introducing the FHM program, defining “the forest” regionally, discussing prominent issues, and

displaying summary FHM data taken from 1996–1999. A website address is provided on the inside back

cover of this report to solicit reader suggestions for improving future FHM reports.

Keywords: regions, biodiversity, disturbance, ecology, long-term, large-scale, watersheds, air quality,

insects, disease, wildland interface, aspen, ecosystems

The Authors

Paul Rogers is an Ecologist in the Interior West Resource Inventory, Monitoring, and Evaluation

Program at the Rocky Mountain Research Station, Forestry Sciences Laboratory, Ogden, UT. His primary

responsibility is to conduct field work and report on Forest Health Monitoring efforts in the Interior West.

He holds a B.S. degree in geography from Utah State University and an M.S. degree in geography from

the University of Wisconsin-Madison. Since beginning his career with the Forest Service in 1987, he has

specialized in conducting large-scale field and remote vegetative surveys.

David Atkins is the Forest Health Monitoring Coordinator for the Northern and Intermountain

Regions of the USDA Forest Service. He is a forest ecologist in Forest Health Protection, State and

Private Forestry, located in Missoula, Montana. His interest is in sustainable forest management for a

broad spectrum of values. He has a B.S. degree in Forest Science from Humboldt State University and an

M.S. in Forest Ecology from the University of Montana.

Michelle Frank is the Forest Health Monitoring Coordinator for the Rocky Mountain Region of

the Forest Service. She is an entomologist working in the Forest Health Management staff unit of

Renewable Resources, located in Denver, Colorado. She has a B.A. degree in biology from Marietta

College, a B.S. degree in forestry from the University of Michigan, and an M.S. degree in entomology

from the University of Maine.

Douglas Parker is the Assistant Director of Forestry and Forest Health, USDA Forest Service,

Forest Health Protection, State and Private Forestry, located in Albuquerque, New Mexico. His current

duties include providing technical assistance to federal, state, and private managers on forest health and

pesticide-use management and coordination. His work interest is the development of herbicide techniques

for use in Integrated Vegetation Management programs for the control of invasive plants and noxious

weeds.
Forest Health Monitoring

in the Interior West:

A baseline summary

of forest issues, 1996–1999

Paul Rogers

David Atkins

Michelle Frank

Douglas Parker

Photos by Paul Rogers unless otherwise noted

USDA Forest Service, Rocky Mountain Research Station,

in cooperation with USDA Forest Service, State and Private Forestry,

Regions 1– 4

Contents

Forest Health Highlights .......................................................................... 1

Introduction ............................................................................................... 3

Overview of the Forest Health Monitoring (FHM) Program ............ 4

What do we mean by a “healthy forest?” (sidebar) ........................... 4

Data Sources ...................................................................................... 4

Plot Network ............................................................................ 4

Survey Component .................................................................. 5

Forest sustainability criteria (sidebar) ............................................... 5

Scope of Report ................................................................................. 6

The Forest Resource ................................................................................. 7

Forest Types ...................................................................................... 8

Ecoregions of the Interior West ......................................................... 8

Land Ownership .............................................................................. 10

Forest Health Issues in the Interior West ............................................. 13

Forest Cover Change ....................................................................... 13

Developed and Wildland Interface .................................................. 16

Insect and Disease Disturbances ..................................................... 17

Watershed Health ............................................................................ 20

Biodiversity ..................................................................................... 21

Air Quality....................................................................................... 23

Emerging Issues .............................................................................. 25

Conclusion ............................................................................................... 27

References ............................................................................................... 29

Appendices

A: Plot Distribution by State and Land Use .................................... 31

B: Distribution of Forest Land in Colorado, Idaho, Nevada,

Utah, and Wyoming by Stand-level Categories ..................... 32

C: Total Tree and Regeneration Counts .......................................... 33

D: Interior West Crown Conditions ................................................. 35

E: Regional Distribution of Damage Types by Species

for Live Trees ......................................................................... 36

F: Data Available From FHM Plots ................................................. 37

G: Contacts For Further Information .............................................. 39

H: Related Reading ......................................................................... 40

1

Forest Health Monitoring (FHM) has been active inthis region since 1992. This is the first regional assessment under the FHM program for the Interior West. It would

be difficult to present a complete health assessment with firsttime measurements. Instead we focus on issues affecting

change on the forested landscape. This baseline report should

be used as a benchmark for comparing future regional assessments. The following highlights represent the prominent

messages presented in this document.

• FHM plot data appear to support the hypothesis of

regional aspen decline. Fire suppression, livestock grazing,

and ungulate browsing favor encroachment by more shadetolerant conifers where aspen once dominated.

• A pressing regional forest health issue is the rapid

expansion of human development near forests. Urban and

rural development in or near forested areas brings forth a

unique set of concerns, such as loss of forest area and wildlife habitat, wildlife-human encounters, fire protection, fire

starts, and forest thinning for life and property protection.

• Insect and disease outbreaks cycle through Interior

West forests. Subalpine fir decline and western spruce budworm are on the rise. Infestations may threaten or regulate

forests depending on human values and proximity to commercial or residential forests.

• Upland changes in vegetation types and density have

drastically altered some watersheds, notably in more arid parts

of the region. Forest health directly affects watershed conditions, including water quality, by regulating the amount, timing, and sedimentation of runoff.

Forest Health Highlights
2

• Regional forests are naturally diverse, from northern Idaho to the Sonoran chaparral. However, people continue to alter biodiversity by introducing exotic plants and

animals and by damaging wildlife habitat through forest

fragmentation.

• Overall, the air quality in the Interior West is very

good. FHM uses vascular plants and lichens as bioindicators

of air pollution effects on forests. Some urban areas and

point sources have had marked effects on downwind lichen

communities surveyed by FHM.
3

Introduction

The Interior West includes Montana, Idaho, Wyoming,

Utah, Nevada, Colorado, New Mexico, and Arizona.

Forests cover about 25 percent of this region (Powell and

others 1993) and provide important recreational opportunities, wildlife habitat, aesthetic benefits, timber products, and

watershed values. In some areas, however, human demands

of the past century have taxed the health and sustainability

of forest ecosystems. Native and exotic pathogens, air pollution, management practices (including logging, grazing, and

fire suppression), and climate change are some of the primary stressors that concern the public, private forest landowners, and land managers. These groups share the responsibility for maintaining long-term viability of the region’s
4

forests, but until recently they lacked consistent information

that spanned ownership and political boundaries.

Monitoring all forest ecosystems is an important first

step in fulfilling stewardship responsibilities. Through appraisal of resource conditions, scientists can evaluate change

and assess significant trends that may deviate from expected

ranges. Forest Health Monitoring (FHM) is a national program designed to determine the status, changes, and trends

in forest conditions, (such as species, landscape, and ecosystem health) on an annual basis. The purpose of this initial

FHM report is to address the prominent forest health (see

sidebar) issues in the Interior West.

Overview of the Forest Health

Monitoring (FHM) Program

FHM measures forest change and assesses the resilience

of ecosystems to disturbances. The United States Forest Service is working closely with state natural resource agencies,

as well as other federal agencies and universities, to implement FHM at four principal levels: Detection Monitoring,

Evaluation Monitoring, Intensive Site Monitoring, and Research on Monitoring Techniques. Detection Monitoring is

designed to detect changes and make preliminary assessments

of significant findings based on systematic data collection.

Baseline data (such as tree species tally, crown measures,

and lichen sampling) presented in this report were collected

at the Detection Monitoring level (see Data Sources). If important unexplained changes are detected, Evaluation Monitoring is activated to investigate the extent and severity of

changes. Intensive Site Monitoring involves establishing a

small national network of sites for research on ecological

processes related to elements of change in specific ecosystem types. Finally, Research on Monitoring Techniques is

charged with developing reliable forest health indicator measurements (such as plant sampling techniques).

FHM reports on forest-related issues on a large scale.

The principal levels of reporting in FHM include state, regional, and national/international (see sidebar, Forest Sustainability Criteria). Local or special reports are produced as

issues arise and where FHM and other data sets are

appropriate for the area of consideration.

Data Sources

Plot Network—A plot is a permanent sample location

that is measured on a regular cycle. The sample area of a plot

is approximately 2.5 acres (1 hectare). Field crews gather

data on tree species and diameters, crown conditions, tree

damage, lichen communities, ozone bioindicators, and soils

(USDA Forest Service 1999). These measurements act as indicators of forest health. Field crews are rigorously trained

in all forest measurements and regularly tested to ensure high

standards of quality. As the program develops, new indicators such as understory vegetation and woody debris may be

added to supplement the current suite of field measurements.

In 1992 the USDA Forest Service and the Colorado State

Forest Service began cooperating to establish permanent FHM

plots across that state’s forested lands. In subsequent years,

Idaho (1996) and Wyoming (1997) were included in the FHM

plot network. Utah and Nevada were added to the program

in 1999. For each state, a baseline measurement of all plots

was performed followed by annual measurements of about

one-fourth of the original plots. In this way a remeasurement

of all the plots is accomplished in a total of 5 years (an additional cycle year was added to each state in 2000). Field plots

are spread evenly across the state in any given year. This

What do we mean by a “healthy

forest”?

A healthy forest displays resilience to disturbance by maintaining a dynamic set of structures,

compositions, and functions across the landscape.

Secondly, healthy forests meet the current and future

needs of people in terms of values, products, and services. These two components are interrelated and may

oppose each other in the short-term. However, forests cannot meet social needs indefinitely without sustained ecological capacity to recover from human or

natural disturbance.
5

system provides annual measurement of forest conditions

across these states and eventually the entire region. Remeasurement of specific forest indicators allow researchers to assess trends in forest conditions. This report contains only data

from first-time, or single visit, measurements.

Survey Component—The survey component of FHM

provides a record of broad-scale disturbance events, such as

large-scale insect and disease outbreaks, that may not be detected by the FHM plot network. Survey information provides a context for interpreting plot data and for identifying

likely factors that contribute to forest health changes.

Aerial detection is the primary survey activity. Systematic aerial surveys of forest conditions have been conducted

in this region for the past 30 years by state and federal cooperators. Other survey activities include: 1) ground surveys

for specific insect and/or disease activity such as dwarf mistletoe and mountain pine beetle; 2) analyses of other plot-based

data from Forest Inventory and Analysis (FIA), National

Forest inventories, and Forest Health Protection insect and

disease plot inventories; and 3) service trip reports and technical reports for historical data or trends.

Forest sustainability criteria

The United States is committed to reporting on the

criteria and indicators of sustainable forests found in the

Santiago Declaration—Montreal Process (Anonymous

1997). Five of the seven internationally agreed upon criteria relate directly to FHM: biological diversity, productive capacity, ecosystem health and vitality, soil and water

resources, and global carbon cycles. The two criteria not

addressed here are the socio-economic and legal aspects

of sustainable forest management. Regional forest health

issues closely parallel the criteria and indicators found in

this agreement. Issues and data summaries found in regional reports contribute to national reporting efforts in

accordance with the Santiago Declaration (Stolte 1997).
6

Scope of Report

This report addresses forest health in two ways: by discussing forest-related issues and by summarizing data in several appendices. FHM is a long-term monitoring program;

therefore, the data presented in this report must be viewed in

that light. This report presents a first-time, or baseline, summary. Subsequent reports will address trends as the current

plots and other detection surveys are remeasured.

In this report, we first describe the forest resource to

familiarize the reader with regional forest cover, ecoregion,

and ownership patterns. The body of this report will focus on

the following forest-related issues in the Interior West today:

1. Forest Cover Change addresses successional changes

in species composition that appear to significantly deviate from patterns found a century ago. Does this

change signal a distressed forest resulting from poor

management, or is this simply a healthy forest developing along an alternative course?

2. Human-populated forests are a special concern and

may affect our perception of healthy forests in a Developed and Wildland Interface setting. On these

lands, many would agree that additional management

of forests is warranted to protect lives and property.

3. Insect and Disease Disturbances fluctuate over time.

We will examine some of the primary agents currently

at work in this region.

4. Watershed Health is a critical issue throughout the

region. How do our forest management actions affect water quality and quantity?

5. Biodiversity is a long-standing issue of concern with

the public. We need to objectively and consistently

address regional diversity, including impacts from

exotic species.

6. Poor Air Quality can broadly affect the health and

vigor of forests. FHM measures impacts of air quality on forest ecosystems using bioindicator plants.

A brief look at emerging issues follows specific issue

discussions.

Data summaries from FHM plot data are found in these

appendices:

A. Plot Distribution by State and Land Use

B. Distribution of Forest Land by Stand-level Categories

C. Total Tree and Regeneration Counts

D. Crown Condition Ratings

E. Distribution of Damage Types by Species

F. Data Available From FHM Plots

Please note that we are interested in your suggestions

and feedback. Appendix G includes sources to contact for

further information. An internet website address is provided

on the inside back cover for further information and to register reader comments.
7

The Forest Resource

The Interior West is noted for its variety of forest cover,from moist cedar-hemlock in the north, to high elevation

spruce-fir, to dry pinyon-juniper in the high deserts. It is important to acknowledge the diversity of regional forests before

proceeding to issue discussions. A regional forest health assessment is really a compilation of many issues applied to a variety

of forest conditions. This section will briefly describe the forest

types, ecological divisions, and land ownerships that often frame

and complicate issues. Previous state inventory reports provide

more detailed information on ownership and forest cover (for

example, O’Brien 1999; or Brown and Chojnacky 1996). Additional sources on the region’s geography and related forest health

references are found in appendix H.
8

Forest Types

Forest type is generally synonymous with forest cover,

or the dominant tree species in the overstory at a given site.

Figure 1 depicts the general distribution of forest types across

this region based on satellite imagery. Forest types taken from

field surveys are a convenient way to group land cover, although sites commonly contain more than one species. For

example, Douglas-fir forest types of central Idaho may contain ponderosa (Pinus ponderosa), limber (P. flexilis), and

lodgepole pine (P. contorta), plus aspen (Populus tremuloides)

and Rocky Mountain maple (Acer glabrum). Forest types are

influenced by factors such as climate, elevation, aspect, soil

type, and disturbance history.

Ecoregions of the Interior West

The forest health issues addressed in this report cross

forest type, ownership, and political boundaries. Past efforts

to assess forest conditions were often hindered by incompatible data within agencies and across political boundaries. A

practical approach to large-scale forest health issues is to use

nonpolitical land divisions, such as ecoregions, to objectively

assess contiguous forests. Bailey’s (1995) Description of the

Ecoregions of the United States presents a hierarchical framework for delineating ecological regions based on their unique

combinations of physiography, soil type, potential vegetation, and climate. An ecoregion approach allows analysts to

group field plots that have similar combinations of these

physical traits.

The ecoregions of the United States are classified, in descending order, by domains, divisions, provinces, and sections.

More than 99 percent of the Interior West lies within the Dry

Domain. There are 14 distinct provinces (ecoregions) found in

the Interior West (figure 2). Detailed descriptions of each of

these provinces are found in Bailey (1995). All of these provinces contain forest conditions that will be sampled by FHM.

Points sampled through 1999 are shown in figure 2.
9

Figure 1—Map of regional forest types derived from satellite imagery at 1 km

resolution in the early 1990s. Source: AVHRR satellite, USDA Forest Service,

Southern Forest Experiment Station, Forest Inventory and Analysis.
10

Land Ownership

FHM samples all owner categories of forested lands.

Management of forested lands across the region is complicated by a variety of ownership philosophies and directives.

Nevada, Utah, and Idaho have greater than 50 percent of their

land base in federal ownership, while the remaining five states

each have more than 25 percent federal land (figure 3). In

contrast, New Hampshire represents the most federally owned

state (13 percent) east of the Rocky Mountains (Riebsame

and Robb 1997). Regionally, most forest acres fall on National Forest or Bureau of Land Management lands, though

significant portions are owned by private individuals or corporations. The remaining portions of the forested land base

consist of State, National Park, Tribal Trust, and miscellaneous federal and county properties.

Figure 2—Ecoregion provinces and FHM plot locations in the Interior West.
11

Figure 3—Interior West land ownership patterns and percent federal ownership. Source:

USDI, Bureau of Land Management, and Riebsame and Robb (1997).
12
13

Forest Health Issues

in the Interior West

Forest Cover Change

Examples of forest cover change cited by land managers in the Interior West include transition of western white pine (Pinus monticola) to Douglas-fir

(Pseudotsuga menziesii) and true fir (Abies sp.) species

in the northern Rockies, invasion of arid land tree and

shrub species into adjacent grasslands in the southwest,
14

and a general trend that favors shade-tolerant species over

seral species throughout the region. These type conversions

are attributed fundamentally to post-settlement impacts on

forest systems resulting from wildfire suppression, termination of aboriginal burning practices, tree cutting, and livestock grazing. Related disturbance cycles (for example, insect

and disease outbreaks or wind-related events) and climatic

variation work in tandem with human disruptions to affect

forest cover change.

Forest Health Monitoring can measure change in species composition, forest structure, and frequency of disturbance by using species make-up, size, age, and relative

dominance of all trees on a particular site. FHM also

describes the condition of individual trees through assessing growth, mortality, regeneration, damage, and estimates

of crown conditions. All of these variables affect forest

cover and may be used to assess long-term change.

This section explores aspen forests as an example of regional cover change. There are some commonalities found between aspen and other tree species in this region; for example,

the proliferation of shade-tolerant species where fire regimes

have been altered. However, beyond their affinity for disturbance, aspen, ponderosa pine, and western white pine react

very differently depending on post-disturbance interactions

of climate, insects, disease, reproductive strategies, and other

factors.

Aspen cover throughout the West appears to be decreasing (Brown 1995; Bartos and Campbell 1998; Rogers and

others 1998; Rogers 2001). Shifts in forest cover occur over

decades, or even centuries, so they may not be obvious to

many forest visitors. Nonetheless, cover changes have

far-reaching effects on a forest’s susceptibility to fire, insects,

or disease. Aspen, the predominant deciduous tree of the Interior West, also supports a unique range of understory

plants and lichens that would likely decline with a loss in

aspen overstory. Finally, aspen are highly valued as a regional

aesthetic resource, providing an autumn shock of yellow

among the sea of evergreen.

 Aspen is one of a few tree species that readily regenerates after fire. Because aspen primarily regenerate by
15

Figure 4—Aspen plot distribution in Idaho, Wyoming,

and Colorado. The combination of plots with aspen

present and unstable aspen forest type plots support

the theory of regional aspen decline.

suckering from underground root stock (see Romme and others 1997 for exceptions), they maintain a certain advantage

over other species whose reproductive parts (cones and seeds)

are often consumed by fire or take longer to establish when

they are not burned. It appears that a sharp reduction in regular burn events in the past century has led to a significant

drop in aspen regeneration. Moreover, when disturbance is

delayed in some stands, older aspen will eventually be replaced by competing conifers at about 80–150 years

(Mueggler 1985). FHM data show that the average age of

aspen forest types is 68 years, while the average age of nonaspen forest type stands (with aspen present) is 89 years. So,

while few stands are regenerating due to the lack of fire, older

stands of aspen are being replaced by shade-tolerant conifers. This basic formula, in combination with other factors

such as grazing and browsing of seedlings, appears to be causing a decline in aspen type area.

 In Idaho, Wyoming, and Colorado most aspen stands

are in the Southern Rockies ecoregion. FHM plots in these

states with aspen present were plotted on the map shown here

(figure 4). Data from Utah and Nevada have not yet been

compiled for this analysis. These plots may be logically split

into aspen forest type (plots dominated by aspen) and plots

dominated by other species where aspen is still present. Fifty

percent of the forested plots with aspen present are now dominated by more shade-tolerant species. Previously, aspen was

the dominant species found in an unknown (presumably

larger) portion of these plots where it is currently only present

in small numbers (Bartos and Campbell 1998; O’Brien 1999).

Lack of large-scale disturbance has favored conifer species

on these sites. The Southern Rockies appear to be more conducive to aspen establishment than surrounding provinces

(figure 4). If indeed a threat to the health of aspen forests

exists regionally, it is plausible that a decline would manifest

itself first near the margins of the species’ natural range (for

example, Front Range of Colorado, figure 4), where climate

and soil may already be limiting factors.

 Plots taken in aspen forest types appear to represent the

stable portion of the aspen community regionally. Further

analysis of stand structure, regeneration, damage, mortality,
16

and age reveals that an additional 21 percent of aspen forest

type plots were found to be unstable (in transition toward

other forest types) in the absence of disturbance (Rogers

2001). Plots were considered unstable by statistical ranking

of 10 tree-related variables: 1) stand age; 2) other species

present; 3) aspen saplings present; 4) other species’ saplings present; 5) aspen in lower canopy; 6) stand age

90 years or greater; 7) aspen mortality greater than 10 percent; 8) severe damage (conks, decays, cankers, and open

wounds) greater than 20 percent; 9) presence of a second

forest condition (forest type) of conifers; and 10) percent

of conifer trees and saplings.

Another view of aspen community health is physical tree

damage. Though deciduous trees typically display more tree

damage than evergreens, aspens had a higher percentage of

damage than any other major species (appendix E). Aspen

also led all species in the most serious forms of damage, “cankers” and “decay.” Seventy-three percent of all aspen damages observed were in these two most serious categories.

Data presented here support the hypothesis of a regional

aspen decline over the last century but do not suggest the

extent of that decline. Future remeasurements of plots, along

with field plots in adjacent states not yet sampled by FHM,

will give us a better idea of the rate and direction of this

apparent trend. A reversal of this trend would logically involve widespread human or natural disturbances coupled with

reductions in grazing and browsing where aspen are

regenerating.

Developed and Wildland Interface

The developed and wildland interface includes expanding urban areas, rural developments and vacation homes, and

public parks, campgrounds, and other recreational facilities

in or near forests. A marked increase in development around

forested lands has been particularly noticeable within the last

10 to 20 years. Data from the U.S. Bureau of Census (1990)

indicates a net increase in population in the region. Six of the

top 10 fastest growing states in the nation are found in the

Interior West: Nevada, Idaho, Arizona, Colorado, Utah, and

New Mexico (Riebsame and Robb 1997).

Over the past 150 years, land has been used for farming,

grazing of livestock, mining, and the production of timber.

Recently, with the large influx of people, land prices have

increased, making it more profitable to sell parcels for building sites than to use them in traditional ways. Rural development may also lead to losses in recreation and aesthetic

opportunities associated with less-developed lands.

In general, human values surrounding the management

of interface lands are slowly changing from “living off the

land” to “living in the land.” Newcomers to the region are

probably accelerating this change in attitude. In the context

of forest health, increased development of forests will initiate more intensive management when disturbance agents

either rapidly or gradually change surrounding forest conditions. For instance, a bark beetle infestation may leave a forest of large dead trees adjacent to valuable homes. These trees

may damage property as they eventually topple, or they may

present a more acute wildfire hazard in particulary dry years.

Potential forest developers and owners buy home sites for

their current aesthetic properties but often are unaware of

changing conditions and potential hazards of interface areas.

There are many preventive measures that can be taken to

buffer homes from wildfire threats, including not building in

fire-prone areas in the first place (Fuller 1991).

Wildlife may be severely impacted in interface zones.

With forest land development there can be disruptions in the

traditional migration routes, feeding sites, winter ranges, or

birthing and denning areas of various wildlife species. Conflicts arise when wildlife invades trash cans, contaminates

swimming pools, or feasts on the front lawn or garden. Some

species prosper in developed areas (for example,skunks [Mephitis mephitis], raccoons [Procyon lotor], deer [Odocoileus

sp.], and coyotes [Canus latrans]), while others struggle for

survival (for example, pine martens [Martes americana],

grizzly bears [Ursus arctos horribilis], and lynx [Felis

lynx]). All of these species may contribute to human and

wildlife conflicts associated with forest and adjacent land

development.

With data from FHM plots, in conjunction with aerial

surveys, we can begin to assess the regional extent of this

issue and inform the public on recommendations for hazard
17

prevention in highly susceptible areas. Maps of tree cover,

damage, fire susceptibility, human development, and population growth are the first step in assessing the extent of the

problem. In most cases private landowners will make the ultimate decisions on what actions are taken. However, adjacent public wildlands will likely be subjected to more intensive management where private properties will be affected

by runaway fires or insect infestations.

Insect and Disease Disturbances

While tree-ring analysis has aided our understanding of

presettlement fire regimes considerably, much less is known

about long-term human impacts, if any, on insect and disease

disturbances (Swetnam and Betancourt 1998). We do know

that climate plays an important role in these events. Interior

West forests experience frequent short-term advances and

declines of insect and disease outbreaks. Many of these perturbations maintain healthy forest functions and species diversity over time. However, outbreaks are often seen as harmful to commercial and residential forests. Insect and disease

events near developed land may provoke secondary disturbances, such as wildfire and hazard tree damage to private

property. For these reasons, FHM tracks insect and disease

occurrences on an annual basis over large areas.

Insect and disease outbreaks are monitored by aerial

detection surveys and through the plot network. Additional

ground surveys augment aerial survey information. Aerial

survey data from 1998 shows infestations of insects and diseases affecting major timber species across the region (figure 5). Currently, subalpine fir decline (an insect and disease

complex) and western spruce budworm (Choristoneura

occidentalis) are affecting the largest acreages in the region.

There is further concern over recent rises in mountain pine

beetle (Dendroctonus ponderosae) outbreaks in the central

and southern portions of this area.

Field crews collect tree damage data on the FHM plot

network (USDA Forest Service 1999). Damages are assessed

based on visible symptoms only (without chopping into the

tree), beginning with the base of the tree and working up and

out to the foliage. Damages found in the roots or lower bole

of a tree generally are more serious than those found at the

Photo by Michael Schomaker
18

Figure 5—Insect and disease disturbances detected from annual aerial surveys, 1998. Subalpine fir decline

and western spruce budworm each affected over 300,000 acres in the region during this year.
19

Photos courtesy of Rocky Mountain Research Station,

Bark Beetle Disturbance Project (RWU-4501)
20

branch tips. In addition to damage locations, damage types

are ranked for significance to growth and mortality of trees.

For example, cankers or decays on the main stem are more

serious than discolored foliage. Not all damages recorded

with this system are related to insects and disease. Percent of

each species with no damage, along with damage types by

species, are shown in appendix E. Site or species-specific

information found on plots can be combined with large-area

aerial survey maps to provide a clearer view of where and

how insects and disease affect regional forests.

Watershed Health

Rivers, streams, and riparian areas have drastically

changed since the mid-19th century. Fire exclusion, beaver

(Castor canadensis) trapping, overgrazing by livestock, wildlife browsing, dam building, and other human water developments have combined with climatic fluctuations to produce

these changes. In some regional watersheds, increased forest

density and changes in species composition have resulted in

decreased runoff to major tributaries.

Upland vegetation conditions regulate groundwater recharge and the proportion of rainfall and snowmelt that

reaches streams directly through runoff. Since the majority

of the April to September streamflow comes from snowmelt

rather than summer rains, the upland forest structure is a critical factor for watershed health. Forests that have converted

from an open-canopy to closed-canopy condition collect more

snow in branches and foliage. A larger portion of this snow

evaporates into the atmosphere without reaching the soil. In

the recent past, average annual precipitation levels have remained unchanged, although less water has been available

for groundwater recharge, streamflow, and herbaceous plant

growth. Reduced groundwater recharge is translated into reduced streamflows and increased water temperature. Some

streams dry up completely during the summer where they

did not previously.

Except for climate, the exclusion of natural wildfires

probably has had the most impact in shaping forest and rangeland ecosystems of low and mid elevations (Covington and

Moore 1994). Reduction in fire frequency has resulted in

increased densities of trees and shrub species in many forest

communities. Grazing and browsing by livestock and wildlife contribute to the increase of woody plants by reducing

competition from grasses and other herbaceous plants. Increased tree and shrub densities result in higher interception

and evapotranspiration rates, thereby reducing the amount

of water available for streamflow. On the other hand, soil

compaction caused by grazing domestic and wild animals

slows infiltration of surface water. Construction of roads

increases runoff through interception and concentration of

surface flows. Together, these factors have generated rapid

runoff and powerful floods, as well as severe soil loss and

even slope failure in some areas (McClelland and others

1997). Flooding occurs because water runs off the surface

rather than being absorbed into the soil and being slowly released to watercourses. Floods have been powerful enough
21

to remove the entire flood plain, incising channels through

old alluvial deposits and destroying much of the riparian vegetation. In wet meadows, channel cutting has reduced water

tables and drained hydric soils.

Dams, reservoirs, and irrigation projects on rivers have

drastically modified channel dynamics, including erosion and

deposition processes (Collier and others 1996). The regeneration of cottonwoods (Populus sp.) and willows (Salix sp.)

depends on natural floods that rarely occur in some river systems. Additionally, many southwestern drainage basins were

managed to eliminate cottonwoods in an effort to increase

water flows (Dunne and Leopold 1978). Human alterations

of stream dynamics and species composition have contributed to the proliferation of exotic trees like saltcedar (Tamarix

sp.), Russian-olive (Elaeagnus angustifolia), and Siberian elm

(Ulmus procera). Their presence has resulted in increasingly

drier riparian systems. Salt in the leaf litter of dense saltcedar

stands has prevented native plants from regenerating. New

plant communities have resulted with different vertical and

horizontal layers, understory species composition, and age

class distribution. Additionally, the richness and abundance

of bird and other wildlife species has been reduced. Changes

in river systems have led to endangered status or complete

loss of some native aquatic species.

Soil that is eroded from disturbances in riparian or upland areas is being deposited into streams. This adversely

affects water quality and aquatic habitats in most streams

where it does occur. Also, high-intensity wildfires in dense

forests often lead to short-term intensification of soil erosion

and sediment delivery to streams. Soil disturbance is particularly acute after heavy rain or snowmelt events in the

months following a burn (Davenport and others 1998).

Our understanding of watershed and forest health interactions is limited because they occur over vast areas that transcend multiple ecological zones. However, we do know that

streams experience long- and short-term disturbance regimes

just as forests do. In the past there were undoubtedly shifts in

stand densities, fluctuations in forest disturbance regimes,

and climatic shifts that caused widely varying hydrologic

cycles and fluvial disturbances. It is difficult to separate longterm vegetation and disturbance patterns from current forest

health assessments. This rule applies equally to watershed

health. Although we know that people have drastically altered some watersheds, we must also realize that periodic

flooding, slope failure, and erosion will take place on forested landscapes that have been marginally affected by human actions. Forest measurements collected through the FHM

program and related studies will help us to better understand

some of these interactions.

Biodiversity

Biodiversity refers to the variety of living organisms occurring in a particular area. Society values sustainable healthy

habitats for native wildlife, vertebrates, vascular plants, and

non-vascular plants. These values stem from future applications in medicine, clean water, and air quality, as well as for

the less tangible spiritual, philosophical, and instrinsic motivations for maintaining a wide variety of life forms. For these

reasons, biological diversity is considered an important indicator of forest health.

Biological diversity is a broad and complex subject that

may be measured with a variety of methods and at multiple

scales. Biodiversity is most often examined at the genetic,

species, or community-ecosystem levels (Langner and Flather

1994; Gaines and others 1999). It may focus on species populations directly or deal with habitat conditions by looking at

the diversity of vegetation structure. The FHM program has

a broad geographic focus with the desire to monitor longterm changes. Therefore the analysis of biodiversity in this

program is primarily at the community-ecosystem level.

Biodiversity measurements currently taken on FHM plots are

tree and lichen species richness and forest structure. We monitor forest structure by examining the size, density, position,

age, and damage of live and dead trees (for example, aspen

cover change analysis). In addition to tree-level measurements, we map changing forest conditions of field plots by

tracking disturbances over time. Procedures for monitoring

understory vegetation diversity, down woody debris, and fuel

loading are being tested for future implementation.

People influence biodiversity in many ways. The introduction of non-native species, often accidental, has caused

major problems. These exotic diseases, insects, or plants can

easily infiltrate native communities. White pine blister rust
22

(Cronartium ribicola) has reduced the western white pine

and whitebark pine (Pinus albicaulis) communities in the

Northern Rockies, tamarisk (Tamarix sp.) has overrun many

riparian zones on the Colorado Plateau, and many invasive

understory “weeds” (for example, dandelion [Taraxacum sp.],

cheatgrass [Bromus tectorum], and Dyers woad [Isatis

tinctoria]) are moving into forested zones. Efforts are underway to eradicate gypsy moth (Lymantria dispar) infestations

detected in the region.

Previous management practices in this region over the

past century, notably fire suppression and logging, have

reduced the percentages of young and old stands, while increasing the percentage of mid-age forests (Langner and

Flather 1994). Great reductions in some forest types, such as

western white pine and aspen, may result in reduced regional

diversity through the loss of associated plant and animal communities. Native diversity is best maintained with a variety

of forest type and stand structure conditions across a landscape or region (Halpern and Spies 1995).

FHM will assess human impacts on biodiversity by using

plot data in combination with pertinent studies conducted elsewhere, for example remote sensing projects already underway

(Merrill and others 1995). As part of the current FHM plot

protocol, field crews note recent natural and human disturbances. Documentation of plot disturbances can be classified

and compared to the number and type of plant species found

on plots as an indicator of human effects on species diversity

and richness (Stapanian and others 1998). FHM will also use

soil and erosion data, in part, to document how recent disturbance has affected basic soil properties. Significant alteration

of the soil can affect the types and richness of communities

that can be supported. Overall, the long-term assessment of

regional diversity will involve a concerted effort to integrate

several types of monitoring activities currently being implemented by agencies and universities around the region.
23

Air Quality

Forest Health Monitoring is concerned with the effects

of air quality on forest vegetation. In areas of consistently

poor air quality, certain plants such as the shrub ninebark

(Physcocarpus malvaceus) or ponderosa pine trees are damaged or show dieback (Mavity and others 1995; James and

Staley 1980). Other plants, notably certain lichen species,

display even less pollution tolerance and may disappear from

affected forest environments.

Lichens gage air quality, add significantly to forest diversity, enhance nutrient cycling, and are a critical food source

for wildlife (McCune 2000). Lichens are sensitive to changes

in air quality because of their

dependence on atmospheric nutrients for survival. FHM crews

collect lichens and rate their

abundance on every field plot.

Lichenologists identify all species and perform data analysis.

Lichen sampling in Colorado, in

conjunction with a supplemental gradient sample in that state,

have produced some interesting

preliminary results (figures 6

and 7). These maps depict the

range of lichen species richness

and associated air quality scores

derived from FHM plots in

Colorado. Reductions in lichen

diversity appear to have taken

place along the Front Range and

near Steamboat Springs

(McCune and others 1998). A detailed lichen survey of the Yampa

Valley is planned for an upcoming Evaluation Monitoring study.

High ozone levels have negatively affected plant and tree

health in the eastern United States and southern California

for decades (Smith 1985). Trees weakened by ozone damage

may be predisposed to damage by other disturbances, such

as fire, insects, disease, and wind storms. Field crews examine bioindicator plants to detect and monitor trends in air

quality (for example, phytotoxicity rates) for ozone near plot

locations. Thus far no ozone damage has been recorded on

FHM plots in the three Interior West states inventoried prior

to the 1999 field season (Smith 1999). Preliminary evaluation

of Utah and Nevada ozone monitoring in 1999 also reveals no

damage to indicator species. The next step in evaluating ozone

effects on forests in this region will be to concentrate

bioindicator sites near areas of known poor air quality.

An ongoing method of observing the effects of air quality on forest health is to evaluate tree foliage conditions on

the FHM plots. Visual crown ratings and damage surveys

have been successfully applied to forest health evaluations

in mixed hardwood stands in Europe and Eastern North

America since the mid 1980s (Tomlinson and Tomlinson

1990). Field crews in the Interior West estimate density, dieback, and transparency of the crowns of all trees on sample

plots (appendix D). Since plot installation began in 1992, no

clear sign of crown decline or damage has been detected in

our region. Future assessment of pollution on forest health

will compare FHM data sets with data collected by a variety

of state and federal agencies that monitor air quality.
24

Figure 6—Lichen

species richness map of

Colorado ecoregions

taken from FHM plot

samples. Generally, the

more species present

(larger map symbols),

the healthier the forest

ecosystem, although

available moisture plays

an important role in

lichen diversity. Pinyonjuniper sites usually

have fewer epiphytic

lichens than montane

forests.

Figure 7—The clustered

(light green) circles

represent gradient

analysis sites where

lichens were sampled in

Colorado. The gradient

is designed to assess

relative tolerance of

lichen species to varying

levels of air pollution;

hence, sites are located

at intervals from known

pollution sites to known

good air quality sites.

Lichen plots on the FHM

grid (dark green) depict

air quality based on the

index developed for

lichen species from the

gradient. Larger circles

represent higher air

quality.

*Data presented here represent the number of standard deviations from the raw air quality score. These

 values are derived from an adjustment made to the raw air quality scores based on elevation.
25

Emerging Issues

The discussion of forest health issues in the preceding sections was not meant to be all encompassing. New issues will emerge, others will decline in

prominence, and some will remain with us for decades. Moreover, local issues are too numerous to

address regionally, and the FHM design makes it impossible to address issues at finer scales without plot

intensification. This does not belittle the importance

of forest-related issues on a smaller scale. Interested

readers may wish to obtain Forest Health Monitoring reports compiled at the state level (see appendix

H), or consult with federal land management districts,

state offices, or university extension units to gain a

perspective on issues of local concern.

Emerging issues are those that FHM has not

looked at thus far, but that we hope to address in

future reports. Among these is forest fragmentation. While closely related to the biodiversity issue,

continued fragmentation from road building, logging, and development may cause severe disruptions

in forest functions (Reed and others 1998; Hargis

and others 1999). Many forest-dependent wildlife

issues are associated with forest fragmentation.

Changes in some use patterns, such as closing forest

roads, are expected to result in measurable improvements to forest fragmentation, forestdependent wildlife, and overall forest health.

Two other criteria (potential forest health issues)

explicitly required by the Santiago Declaration (Anonymous

1997) are global carbon cycles and soil resources. Both of

these issues involve measurement of basic ecological variables to gain an understanding of the long-term sustainability of forest ecosystems. Measuring global carbon cycles involves monitoring the balance of carbon going into and

coming out of forest systems. Carbon is stored in biomass

above ground and below ground in organic material (live and

dead decaying organisms). Future FHM surveys plan to measure understory vegetation and down woody debris. This information, combined with current tree measurements, will

assist analysts in calculating regional and national carbon

budgets. “Soil health” will give us information on the quality of the soil resource that supports the forest. Loss of topsoil or contamination by foreign chemicals could significantly

degrade forest sustainability. An FHM soil indicator is in pilot mode and is planned for national implementation during

the 2001 field season.
26
27

Conclusion

Consistent long-term monitoring over large regions iscritical to both the overall understanding of how healthy

forests function and to the detection of human-caused changes

in forests over time. This baseline report of FHM data has

presented an overview of forest-related issues affecting the

Interior West today. This region covers many ecological provinces, so analysis will be difficult because of this breadth.

FHM was conceived to detect changes at ecoregional, regional, and national levels. In effect, both the plot and survey components of FHM act as a “broad net approach” to

monitoring forests. Some issues, such as monitoring endangered species, will be better dealt with at smaller geographic
28

scales or with more intense surveys designed for specific

concerns.

Issues of concern today may only be fully understood

through the collection and analysis of long-term data sets,

such as those being provided by FHM. We anticipate forest

health issues changing in the future. The FHM program will

continue to monitor new and evolving issues.

Forest health issues can be quite complex. This initial

report has likely raised more questions than it has answered.

Moreover, human values regarding what actions to take, or

not to take, complicate forest-related issues. In this report we

have attempted to remain objective in describing issues and

have purposely not provided prescriptions. Individuals and

organizations concerned with forest management must weigh

the evidence and decide for themselves where action is warranted. It is through further monitoring, analysis, and public

discussion that we hope to stimulate participation and understanding, and possibly even consensus, among forest users.
29

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fragmentation and landscape pattern on American martens.

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in the United States. Gen. Tech. Rep. RM-GTR-244. Fort

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species of plants which are native to the Western United States.

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31

Plot Distribution in the Interior West by State and Land Use

(totals are in fractions of plots)

Land Use Category Colorado Idaho Utah Nevada Wyoming Region 

Timberland 91.59 124.76 36.28 5.25 50.40 308.28

Woodland 46.02 8.25 86.99 58.51 7.87 207.64

* Inaccessible 9.25 3.00 11.03 26.00 4.25 53.53

Non-Forest 267.14 188.99 200.70 359.24 329.48 1345.55

Totals 414.00 325.00 335.00 449.00 392.00 1915.00

* Inaccessible plot locations were not visited because private landowners denied access or

plot locations were difficult to safely sample (for example, steep terrain).

Appendix A: Plot Distribution by State and Land Use
32

Appendix B: Distribution of Forest Land in Colorado, Idaho, Nevada,

Utah, and Wyoming by Stand-Level Categories

Stand-level category % of plots Stand-level category % of plots

Forest type group Number of seedlings/acre

 Douglas-fir 11.97 0–999 74.96

 Ponderosa pine 6.91 1000–1999 10.96

 Lodgepole pine 10.53 2000–2999 4.97

 Spruce/fir 14.00 3000–3999 2.54

 Grand fir/white fir 5.12 4000–4999 1.54

 Blue spruce 0.15 5000–5999 1.26

 5-Needle pines 1.16 6000+ 3.77

 Misc. sfwd. timberland 2.31

 Aspen 6.83 Number of snags/acre

 Misc. hrwd. timberland 0.75 0 35.82

 Pinyon-juniper 33.32 1–24 41.40

 Misc. hrwd. woodland 6.63 25–49 13.15

 Other timberland 0.32 50–74 5.17

75–99 1.93

Stand origin 100+ 2.53

 Natural 99.40

 Planted 0.60 Basal area (ft.2

)/acre

0–39 21.59

Stand size 40–79 21.98

 Sawtimber 59.59 80–119 21.93

 Poletimber 30.42 120–159 18.17

 Seedling/sapling 9.01 160+ 16.33

 Non-stocked 0.98

Stand age* (years)

 0–50 13.02

 51–100 52.92

 101–150 25.87

 151–200 4.90

 201–250 1.53

 250+ 1.76

* Woodland forest types (207.64 plots) are excluded from stand age.
33

Appendix C: Total Tree and Regeneration Counts

(con.)

* Mature Trees are those greater than 5.0 inches at breast height or root collar. Species marked

with a (w) were measured at root collar due to typically irregular form at breast height.

*Mature Trees Sampled by Species

0 500 1000 1500 2000 2500

White fir

Grand fir

Corkbark fir

Subalpine fir Western juniper (w) Utah juniper (w) Rocky mountain juniper(w)

One-seed juniper (w)

Western larch Engelmann spruce Blue spruce Whitebark pine

Bristlecone pine Common pinyon (w) Lodgepole pine Limber pine

Jeffrey pine Western white pine Ponderosa pine Singleleaf pinyon (w) Douglas-fir

Western redcedar

Western hemlock

Mountain hemlock Rocky mountain maple (w) Bigtooth maple (w)

Paper birch Curlleaf mtn-mahogany (w) Alder-leaf mtn-mahogany (w) Quaking aspen

Black cottonwood

Narrowleaf cottonwood Gambel oak (w)

Number of trees

live

dead
34

Appendix C: (continued)

* Actual number of gambel oak seedlings is 1,779. To improve the overall graphic, the full 

number was not displayed here.

** Saplings are trees with diameters between 1.0 inches and 5.0 inches at breast height or

root collar. Saplings marked with a (w) were measured at root collar due to typically irregular

form at breast height. Seedlings are trees less than 1.0 inches at breast height or root collar

and greater than 1 foot in total height.

Regeneration Sampled by Species

0 200 400 600 800 1000

White fir

Grand fir

Corkbark fir

Subalpine fir Western juniper (w) Utah juniper (w) Rocky mountain juniper(w) One-seed juniper (w)

Western larch Engelmann spruce Blue spruce Whitebark pine

Bristlecone pine Common pinyon (w) Lodgepole pine Limber pine Western white pine Ponderosa pine Singleleaf pinyon (w) Douglas-fir

Western redcedar

Western hemlock

Mountain hemlock Rocky Mountain maple (w) Bigtooth maple (w) Paper birch Curlleaf mtn-mahogany

Alder-leaf mtn-mahogany Quaking aspen

Narrowleaf cottonwood

Plains cottonwood

Bur oak * Gambel oak (w) Pacific yew

Number of trees

**Saplings

**Seedlings
35

*Dieback is the percent of the tree

 crown that has died from the branch

 tips inward toward the center of the 

 crown. The graph here clearly shows 

 that most trees in the region have 

 little or no dieback. Only 1.2% of all

 trees in the region have a dieback 

 of more than 25%. Dieback over 

 25% is more prominent in hardwoods 

 (3.1%) than softwoods (0.9%).

* Total crown sample: 

Hardwoods = 1,946

 Softwoods = 10,293

Total = 12,239

*Transparency is the percent of light

that passes through the foliated part

of the crown, excluding tree branches

and main stems. Most trees in the 

region have transparencies from 10–

20%. Overall, there are 2.4% of trees 

with greater than 25% transparency.

Hardwoods have a significantly

greater percent (8.1) than softwoods

(1.4) of transparency ratings over

25%.

*Density refers to the percent of the

crown area that blocks light from 

passing through. This rating does

include the woody portions of the 

crown, so it is not the exact opposite

of foliage transparency. Currently,

94% of all trees fall between 25–75%

density. Trees with less than 25%

density are likely showing signs of 

severe decline, while most trees with

greater than 75% density will be 

generally vigorous. Higher

percentages of hardwoods (8.4) than

softwoods (3.5) have density ratings

below 25%.

Crown dieback

0

2000

4000

6000

8000

0 10 20 30 40 50 60 70 80 90 99

Percent dieback

Number of trees

hardwoods

softwoods

Crown density

0

500

1000

1500

2000

0 10 20 30 40 50 60 70 80 90 99

Percent density

Number of trees

hardwoods

softwoods

Foliage transparency

0

1000

2000

3000

4000

5000

0 10 20 30 40 50 60 70 80 90 99

Percent transparency

Number of trees

hardwoods

softwoods

Appendix D: Interior West Crown Conditions
36

trees with no # damages conks and open cracks and broken brooms broken loss of apic. broken excess. damaged discolored

damage (%) recorded** cankers decays wounds resinosis seams bole on bole roots dominance branches branching shoots foliage other

Softwoods

 Douglas-Fir 1116 (87) 199 15 34 14 7 1 2 0 0 69 26 30 0 1 0

 Ponderosa Pine 322 (80) 110 7 14 26 0 3 0 0 1 20 10 19 0 10 0

 Lodgepole Pine 1466 (71) 810 117 92 221 10 4 3 2 1 140 69 139 0 11 1

 Subalpine Fir 982 (81) 281 59 60 41 7 4 4 2 1 65 29 5 0 4 0

 Engelmann Spruce 921 (84) 212 23 18 34 23 2 0 0 3 61 39 9 0 0 0

 Other Softwoods 927 (84) 218 11 61 40 3 4 4 0 2 57 20 3 1 11 1

 Softwood Woodland 2007 (65) 1580 35 83 738 22 0 15 0 4 160 453 46 3 21 0

Subtotal, Softwoods 7741 (75) 3410 267 362 1114 72 18 28 4 12 572 646 251 4 58 2

Hardwoods

 Aspen 693 (56) 756 328 238 60 3 2 2 0 0 65 51 0 7 0 0

 Cottonwood 28 (52) 31 0 14 3 0 0 0 0 0 6 8 0 0 0 0

 Other Hardwoods 13 (62) 9 0 2 1 0 0 0 0 0 4 2 0 0 0 0

 Hardwood Woodland 413 (64) 281 2 19 59 0 0 4 1 0 27 117 13 36 3 0

Subtotal, Hardwoods 1147 (59) 1077 330 273 123 3 2 6 1 0 102 178 13 43 3 0

Totals 8888 (73) 4487 597 635 1237 75 20 34 5 12 674 824 264 47 61 2

Appendix E: Regional Distribution of Damage T

Total sample size = 12,239 trees

** # of damages recorded may include multiple damages, up to 3, for individual trees.

ypes by Species for Live Trees (5 inch dbh/drc and larger)
37

Appendix F: Data Available From FHM Plots

 Variable name Data type* Variable name Data type*

MENSURATION, CROWNS, DAMAGE

Plot level

County number code Current plot status code

Elevation num. FHM region code

Hexagon (location number) num. Measurement type code

Overlap code Old plot status code

Panel code Quality assurance status code

Plot mensuration year num. Plot number num.

Plot status code Plot type code

Project code State code

Condition level

Condition class num. Condition class change code

Density check code Disturbance year 1 num.

Disturbance year 2 num. Disturbance year 3 num.

Forest type code Land use class code

Past disturbance 1 code Past disturbance 2 code

Past disturbance 3 code Previous stand age num.

Stand age num. Stand origin code

Stand size code

Tree level (trees, saplings, site trees)

Basal area factor (site tree) num. Cause of death code

Competing basal area num. Crown density num.

Crown diameter (mean) num. Crown dieback num.

Crown light exposure code Crown position code

Crown vigor (saplings) code Current tree history code

DBH(diameter breast height) num DRC (diameter root collar) num.

Damage 1–3 code Description (tree notes) alpha.

Foliage transparency num. Ground year num.

Live crown ratio num. Location (damage) 1–3 code

Mortality year num Nonforest year num.

Old DBH num. Old DRC (woodland) num.

Old stem count (woodland) num. Old tree history code

Severity (damage) code Species code

Stem count (woodland) num Tree age at DBH num.

Tree height num.

Understory cover and seedlings

Crown light exposure code Crown position code

Crown vigor code Percent ferns num.

Percent herbs num. Percent moss num.

Percent seedlings num. Percent shrubs num.

Seedling count num. Species code

*Data types: num. = numeric value code = numeric code alpha. = letters or words

(con.)
38

Appendix F: (continued)

 Variable name Data type* Variable name Data type*

SOILS (soil sampling, erosion)

A texture code A thickness (N,S,E,W) num.

Depth to subsoil num. Litter decomposition alpha.

Litter depth 1–3 num. O thickness (N,S,E,W) num.

Percent bare (mineral) soil num. Percent litter cover num.

Percent plant cover num. Slope length num.

Underlying texture code

OZONE BIOINDICATORS

Amount of injury code Bio site availability code

Bio site disturbance code Bio site status code

First species code Number of plants 1–3 num.

Plot moisture code Plots size code

Second species code Severity of injury code

Soil depth code Soil drainage code

Third species code

LICHEN COMMUNITIES

Species alpha. Abundance code
39

Appendix G: Contacts for Further Information...

Kenneth Stolte William Boettcher, Director

Acting National Program Manager Forest Health Protection

USDA Forest Service Intermountain and Northern Regions

Southern Research Station USDA Forest Service

3041 Cornwallis Road P.O Box 7669

Research Triangle Park, NC 28802 Missoula, MT 59807

(919)549-4022 (406)329-3280

David A. Anderson, Director Dwane Van Hooser,

Renewable Resources Interior West Program Manager

Rocky Mountain Region Rocky Mountain Research Station

USDA Forest Service USDA Forest Service

P. O. Box 25127 507 25th Street

Denver, CO 80225 Ogden, UT 84401

(303)275-5026 (801)625-5388

Leonard Lucero, Director

Forestry and Forest Health

Southwestern Region

USDA Forest Service

517 Gold Avenue, SW

Albuquerque, NM 87102

(505)842-3240

Forest Health Monitoring Web Sites:

National Program: www.na.fs.fed.us/spfo/fhm

Regional Forest Health Protection Sites: www.fs.fed.us/r2/fhm/

Regional Forest Inventory/Analysis: www.fs.fed.us/rm/ogden/index.html
40

Appendix H: Related Reading

Atkins, D.; Byler, J.; Livingston, L.; Rogers, P.; Bennett, D. 1999.

Health of Idaho’s forests: a summary of conditions, issues, and

implications. Report No. 99-4. Missoula, MT: U.S. Department

of Agriculture, Forest Service, Northern Region, Forest Health

Protection. 44 p.

Dahms, C.W.; Geils, B.W., eds. 1997. An assessment of forest

ecosystem health in the Southwest. Gen. Tech. Rep. RM-GTR295. Fort Collins, CO: U.S. Department of Agriculture, Forest

Service, Rocky Mountain Forest and Range Experiment

Station. 97 p.

DeByle, N.; Winokur, R., eds. 1985. Aspen: ecology and management in the WesternUnited States. Gen. Tech. Rep. RM-GTR119. Fort Collins, CO: U.S. Department of Agriculture, Forest

Service, Rocky Mountain Forest and Range Experiment

Station. 283 p.

Riebsame, W.; Robb, J., eds. 1997. Atlas of the New West: portrait

of a changing region. New York, NY: W.W. Norton & Company.

192 p.

Rogers, P.; Schomaker, M.; McLain, W.; Johnson, S. 1998. Colorado

Forest Health Report 1992–95: a baseline assessment. Colorado

State Forest Service, Fort Collins, CO, and U.S. Department

of Agriculture, Forest Service, Rocky Mountain Research

Station, Ogden, UT, and Rocky Mountain Region, Denver, CO.

44 p.

Spiegel, L.; Rogers, P.; Frank, M.; Atkins, D. 2001. Wyoming forest

health: a baseline report. In press. Wyoming State Forestry

Division, in cooperation with U.S. Department of Agriculture,

Forest Service, State and Private Forestry, Denver, CO and

Forest Service Research, Ogden, UT.

Stolte, K. 1997. 1996 National technical report on forest health.

FS-605. Washington, DC: U.S. Department of Agriculture,

Forest Service. 47 p.

U.S. Department of Agriculture, Forest Service. 1996. Status of the

Interior Columbia Basin: summary of scientific findings. Gen.

Tech. Rep. PNW-GTR-385. Portland, OR: U.S. Department

of Agriculture, Forest Service, Pacific Northwest Research

Station; U.S. Department of the Interior, Bureau of Land

Management. 144 p.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its

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disability, political beliefs, sexual orientation, or marital or family status. (Not all

prohibited bases apply to all programs.) Persons with disabilities who require alternative

means for communication of program information (Braille, large print, audiotape, etc.)

should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD).

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Room 326-W, Whitten Building, 1400 Independence Avenue, SW, Washington, DC

20250-9410 or call (202) 720-5964 (voice or TDD). USDA is an equal opportunity

provider and employer.

The Rocky Mountain Research Station develops scientific information and

technology to improve management, protection, and use of the forests and

rangelands. Research is designed to meet the needs of National Forest

managers, Federal and State agencies, public and private organizations,

academic institutions, industry, and individuals.

Studies accelerate solutions to problems involving ecosystems, range,

forests, water, recreation, fire, resource inventory, land reclamation,

community sustainability, forest engineering technology, multiple use

economics, wildlife and fish habitat, and forest insects and diseases. Studies

are conducted cooperatively, and applications may be found worldwide.

Research Locations

Flagstaff, Arizona Reno, Nevada

Fort Collins, Colorado* Albuquerque, New Mexico

Boise, Idaho Rapid City, South Dakota

Moscow, Idaho Logan, Utah

Bozeman, Montana Ogden, Utah

Missoula, Montana Provo, Utah

Lincoln, Nebraska Laramie, Wyoming

*Station Headquarters, Natural Resources Research Center,

2150 Centre Avenue, Building A, Fort Collins, CO 80526

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ROCKY MOUNTAIN RESEARCH STATION