JOHN E. MITCHELL

A Technical Document Supporting the 2000

USDA Forest Service RPA Assessment

A Technical Document Supporting the 2000

USDA Forest Service RPA Assessment

U.S. DEPARTMENT OF AGRICULTURE FOREST SERVICE

Rangeland Resource Trends

in the United States

Rangeland Resource Trends

in the United States
Mitchell, John E. 2000. Rangeland resource trends in the United States: A technical document 

supporting the 2000 USDA Forest Service RPA Assessment. Gen. Tech. Rep. RMRS-GTR-68. Fort 

Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 

84 p.

Keywords: rangeland health, rangeland management, weeds, grazing, livestock, sustainability, 

Conservation Reserve Program

Abstract

This report documents trends in America’s rangelands as required by the Renewable Resources 

Planning Act of 1974. The Forest Service has conducted assessments of the rangeland situation for 

30 years. Over this period, rangeland values and uses have gradually shifted from concentrating 

upon forage production and meeting increasing demand for red meat to a more broad-based 

understanding under a framework of sustainable resource management. The total extent of 

rangeland will likely continue a trend of slow decline, but any changes will be small in relation 

to the total U.S. grazing land base of about 800 million acres. Lands enrolled in the Conservation 

Reserve Program are not expected to affect this trend. Data from various sources indicate that 

range condition has been fairly static over the past decade. Non-indigenous weed invasions have 

offset advances in rangeland health. Regardless, the productive capacity of U.S. rangelands is not 

expected to degrade because of slowly decreasing livestock utilization and possible advances in 

biotechnology. Trends in the number of people with adequate technical skills to manage rangelands 

and conduct research need closer attention.

This publication is also available on the web at http://www.fs.fed.us/rm.

You may order additional copies of this publication by sending 

your mailing information in label form through one of the 

following media. Please send the publication title and number.

 Telephone (970) 498-1394

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 Rocky Mountain Research Station

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Rangeland Resource Trends in the United States:

A Technical Document Supporting the 

2000 USDA Forest Service RPA Assessment

John E. Mitchell

Contents

Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Chapter 1: Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

 Early Assessments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

 Criteria and Indicators of Sustainability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Chapter 2: Extent of Rangelands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

 World’s Rangelands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

 U.S. Grazing Lands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

 Non-Federal Grazing Lands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

 Non-Federal Rangelands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

 The Conservation Reserve Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

 National Forest System Lands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

 Rangelands Managed by the Bureau of Land Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

 Outlook for the U.S. Rangeland Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Chapter 3: Rangeland Health . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

 Condition of Non-Federal Rangelands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

 Pacifi c Coast Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

 Rocky Mountain Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

 South Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

 North Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

 Condition of Federal Rangelands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

 Lands Managed by the Bureau of Land Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

 Lands Managed by the Forest Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

 Riparian Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

 Lands Managed by Department of Defense. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

 Expansion of Woodlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

 Decline of Quaking Aspen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

 Non-Indigenous Plants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

 Leafy Spurge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

 Knapweeds and Starthistles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

 Saltcedar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

 Non-Indigenous Thistles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

 Purple Loosestrife . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

 Cheatgrass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
 Other Non-Indigenous Weeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

 Non-Indigenous Weeds on National Forest System Lands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

 Future Impacts of Non-Indigenous Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

 Biological Diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

 Productive Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

 Ecosystem Health . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

 Soil and Water Conservation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Chapter 4: Maintenance of Productive Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

 Advances in Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

 Research and Development Budgets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

 Advances in Agricultural Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

 Application of Existing Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

 Changes in Rangeland Health. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

 Riparian Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

 U.S. Livestock Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

 Cattle and Sheep Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

 Distribution of Cattle Operations and Cattle by Herd Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

 Grazing Use on Federal Lands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

 Consumption of Red Meat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

 Domestic Consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

 Meat Exports and Imports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Chapter 5: Institutional Framework for Rangeland Conservation and 

Sustainable Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

 Rangeland Science Education. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

 Trends in Persons Employed in Rangeland Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 1

Chapter 1: Introduction

This Range Assessment, like those preceding it, ad -

dresses contemporary topics while continuing a baseline 

appraisal of the central theme for all range assessments: 

the demand for and supply of forage in the United States. 

It examines both anticipated supply and future demand 

from a different perspective, however. The U.S. Department of Agriculture no longer maintains a model system 

with a 50-year outlook like that used in the previous 

two rangeland assessments. Therefore, an alternative approach, scenario analysis, was selected to project forage 

demand, and is described in a separate report (Van Tassell et al. 1999). Supply projections are still tied to land 

use changes, but increases in rangeland resulting from 

conservation programs are no longer anticipated (Chapter 2: Extent of Rangelands). Advances in technology are 

not expected to signifi cantly change the overall forage 

supply (Chapter 4: Maintenance of Productive Capacity), 

although this opinion is not unanimous. Van Tassell et al. 

(1999) concluded that changes in forage production technology would enhance the use of some grazing lands, especially in the South.

Four Assessment Regions are used to describe data and 

other information on U.S. rangelands: the Pacifi c Coast 

(PC), Rocky Mountain (RM), Northern (NO), and Southern (SO). 

Criteria and Indicators of Sustainability

Determining the supply of natural resource outputs at 

a national level requires an evaluation of factors infl uencing their level of expression in the environment. One 

effort for identifying criteria and indicators (C&I) of sustainable forests at a national scale, the Montreal Process, 

has become widely recognized. Moreover, the concept of 

using C&I as factors for evaluating all facets of sustainability, including resource supplies, is being increasingly 

accepted. The Montreal Process has converged on 7 criteria and 67 indicators for the sustainability of temperate 

and boreal forests, ultimately recognized in the Santiago 

Declaration of 1995. 

Work is presently in progress to evaluate the applicability of the Montreal Process C&I to rangelands. At 

least four criteria (Conserving biological diversity, maintenance of productive capacity of rangeland ecosystems, 

maintenance of rangeland health and vitality, and conservation and maintenance of soil and water resources) are 

expected to relate directly to rangeland resource outputs. 

The other three criteria contain indicators having important, if less direct, impacts on the supply and demand for 

Executive Summary

rangeland resources. Chapter 2 (Extent of Rangelands), 

Chapter 3 (Rangeland Health), and Chapter 4 (Maintenance of Productive Capacity) are written with criteria of 

the Montreal Process in mind.

Chapter 2: Extent of Rangelands

Area of rangeland is an indicator of ecosystem diversity at a national scale. Although more than half of all 

the ecosystem types determined to have lost more than 

98 percent of their pre-settlement extent are grasslands 

or shrublands, this total is weighted heavily by the neartotal disappearance of tallgrass prairie and extensive conversions of the mixed-grass plains and Palouse prairie to 

agricultural use prior to the 1930’s. There is no indication that endangered rangeland ecosystem types are now 

being lost except for desert grasslands. 

The amount of grazing land and rangeland in the 

United States is expected to continue to decline slowly 

over the next 50 years. However, land use shifts away 

from grazing use will be much greater in areas of more 

rapid population increases and concomitant appreciating land values. Whether the Rocky Mountains and their 

foothills will continue to dominate locations of high immigration by the year 2050 is unknown. Research supporting forage demand projections, however, suggests 

that changes in land use will decrease the amount of 

land available for grazing to a greater extent in a consolidated Pacifi c Coast and Rocky Mountain Assessment 

Region than either the North or South Assessment Regions throughout the foreseeable future.

Chapter 3: Rangeland Health

Rangeland health is connected to the broader concepts 

of sustainability and sustainable management. Three indicators gauge the maintenance of ecosystem health under 

the Montreal Process: Area and percent of rangeland affected by processes or agents beyond the ranges of historic variation; area and percent of rangeland subject to 

specifi c levels of air pollution or ultraviolet B that may 

cause negative ecosystem impacts; and area and percent 

of rangeland with diminished biological components indicative of changes in fundamental ecological processes. 

Invasions of exotic species, fi re, drought, and grazing 

are examples of agents and processes that have apparently occurred beyond their range of historic variation on 

U.S. rangelands during the past 150 years. Fire is a natural and important component of many U.S. rangelands, 
2 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

Executive Summary

but fi re prevention and suppression programs over the 

past 70 years have resulted in a major shift in fi re frequencies. Expansion of non-indigenous weeds and changes in 

grazing have also been considered in this chapter. Measured at the site level, range condition has remained fairly 

static since the last assessment. 

A number of indicators have been developed as part 

of the Montreal Process for evaluating how well a nation 

maintains its soil and water resources. Among them are 

the area and percent of rangeland with signifi cant soil 

erosion, and percent of stream length in which stream 

fl ow and timing have signifi cantly deviated from the historic range of variation. Although there are national data 

sets for soils, water quality, and stream fl ow, they have 

such varying degrees of coverage, compatibility, and recency that comprehensive analyses of them are problematic. The Proper Functioning Condition (PFC) approach 

for rating the health and functioning of riparian zones 

could well serve as an adequate method for reporting the 

percent of stream reaches with abnormal stream fl ow and 

timing.

The vast expanses and remoteness of rangelands, both 

in the U.S. and globally, make assessing these indicators 

of health and vitality diffi cult. No national monitoring 

framework is in place to collect data on long-term or 

episodic processes and agents over time. The best data 

available for the ecosystem health criterion may be for its 

second indicator because of national networks to monitor 

air quality.

There are no hard rules for summarizing these or other 

criteria to determine rangeland health. Individual conclusions will vary from person to person and organization 

to organization. Thus any collective overview can only 

be reached through values and objectives of society as expressed primarily through society’s refi nement process of 

laws and regulations. 

Chapter 4: Maintenance of Productive 

Capacity

Montreal Process indicators for productive capacity 

address the area of rangeland and total biomass available 

for grazing, and the annual removal of forage compared 

to that determined to be sustainable. These indicators are 

diffi cult to monitor and document on a national scale, and 

efforts have not been adequate. However, given the projection that livestock utilization of grazing land will decrease in the Pacifi c Coast, Rocky Mountain, and Northern Assessment Regions and not change signifi cantly in 

the Southern, we can expect that the overall U.S. productive capacity will not be degraded. The slow decline 

in grazing land base may be offset, in part, by equally 

slow increases in rangeland health and advances in grazing technology. Projected slowly rising consumption of 

red meat should not create extensive new demands for 

forage. For that and other reasons, lands in the Conservation Reserve Program, described in Chapter 2, are not expected to have even a moderate effect on livestock numbers. They have been shown to have a positive infl uence 

on some wildlife species at the regional level, however. 

A proliferation of non-indigenous weeds, explained in 

Chapter 3, could feasibly impact the productive capacity 

of rangeland, regionally. If demands for forage ever 

exceed supply, however, market forces should prompt 

shifts in land use from agriculture to grazing land, such 

as described in Chapter 2.

Since there is no reason to expect signifi cant increases 

in the rangeland base, advances in technology affecting 

productivity of rangeland forage species, or restoration of 

rangeland health, we must conclude that the supply of 

forage in the United States is not likely to change signifi -

cantly over the next few decades. The country’s productive capacity should remain adequate to promote sustainable management of U.S. rangelands, however.

Chapter 5: Institutional Framework for 

Rangeland Conservation and Sustainable 

Management

This chapter focuses on the probability of maintaining 

a critical mass of people with adequate technical skills to 

properly manage rangelands, educate students, and conduct needed research and development. The outlook is 

not optimistic. Although job opportunities have diversifi ed, as have university curricula, trends in numbers of 

students have been mixed. Numbers of students training 

to be researchers have declined. Numbers of persons employed in rangeland management by the Forest Service 

and Bureau of Land Management have declined signifi -

cantly, while the Natural Resources Conservation Service 

has held constant.

An aging population of rangeland managers and educators has signifi cant implications for our ability to maintain that critical mass of people with adequate technical 

skills.

Acknowledgments

The rangeland component of the 1999 RPA range assessment was begun under the capable direction of Linda 

A. Joyce, Project Leader, Rocky Mountain Research Station. This assignment was passed to the present author in 

the fall of 1995. Dr. Joyce was instrumental in facilitating 

a smooth and effective transition at that time. Since then, 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 3

Executive Summary 

she has never hesitated to share her experience and insights concerning all aspects of preparing an assessment 

document. These contributions are gratefully recognized.

Much of the data acquisition and summarization was 

carried out by Alicia Goddard, a Colorado State University graduate student employed by the Rocky Mountain Research Station as a rangeland management specialist. Her work was an essential component of updating the 1989 RPA range assessment. In addition, Ms. Goddard conducted the analyses relating to demographic and 

land-use changes on U.S. rangelands.

Projections of demand for forage were estimated by a 

team of three range economists led by Drs. E.T. Bartlett, 

Professor of Rangeland Ecosystem Science, Colorado State 

University, and Larry W. Van Tassell, Professor of Agricultural Economics, University of Wyoming (who now is 

Head, Department of Agricultural Economics and Rural 

Sociology, University of Idaho). Dr. Neil Rimbey, Extension Professor of Range Economics, University of Idaho, 

worked closely with them. Their work, which infl uenced 

the contents of this document, is published in a separate 

report (Van Tassell et. al. 1999).

Investigations concerning the extent and distribution 

of non-indigenous weeds were led by Dr. George Beck, 

Professor of Weed Science, Colorado State University, and 

his graduate student, Ms. Suellen May. A review and 

analysis of rangeland biodiversity was carried out under 

the guidance of Dr. Dan Milchunas, Research Associate in 

Rangeland Ecosystem Science, Colorado State University. 

The results of his research has been submitted for publication elsewhere.

I am grateful to Forest Service range management staff 

offi cers for data and valuable advice. Included in this 

group are Rita Beard, Van Elsbernd, and Jim Montoya 

in Fort Collins; Daryl Herman and Dr. Larry Bryant in 

the Washington Offi ce; and regional staff offi cers Jim Olivarez, Bruce Fox, Charlie Richmond, Dave Stewart, John 

Conner, Bob Hamner, Curt Johnson, Dick Lindenmuth, 

and Levester Pendergrass. Many others at the Forest and 

District levels helped provide needed information. Dr. 

Alison Hill, National Grassland Ecologist, served a valuable role as a liaison with the Vegetation Management 

and Protection Research Staff.

Other agencies contributed data and results of other 

assessments for my use. I am especially appreciative 

to Steve Brady, Natural Resources Conservation Service 

(NRCS), for facilitating access to and analysis of the National Resources Inventory data. Tom Roberts, Bureau of 

Land Management, was directly involved in helping appraise the breadth of pinyon-juniper expansion; he also 

helped in other ways.

Finally, the RPA specialists in Fort Collins, Drs. Curt 

Flather, Deborah Shields, John Hof, and Tom Brown, made 

preparation of the rangeland assessment easier by providing guidance and sharing information. Dr. Linda Langner, 

WO RPA staff, was liaison offi cer for this assignment, and it 

could not have been completed without her direction. Mark 

Delfs, RPA Branch Chief for Assessments and Analysis, facilitated after Dr. Langner was called to another assignment. 

Dr. H. Fred Kaiser, Jr. and Dr. Dave Darr provided continual 

support and counsel. So, in reality, the following document 

represents a group effort with many contributors.

USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 5

The status of rangelands in the United States has been 

of continual interest to the Congress and American people 

since the western states were occupied by Europeans. 

Until 1854, the issue for the federal government was one 

of acquisition. A decade later, however, the Homestead 

Act of 1862 marked the beginning of an era of land disposal. This western expansion for minerals, forage, and 

timber was considered our country’s “manifest destiny” 

(Clawson 1983).

During the 100 years following the Civil War, U.S. 

rangelands were almost exclusively used for livestock 

grazing. During the 1880’s, the number of cattle in the 17 

western states proliferated almost six-fold from 4.5 million head to nearly 27 million head (Poling 1991). This 

was the high water mark of the prominent cattle barons 

fi nanced by European capital (Mitchell and Hart 1987). At 

the same time, the number of domestic sheep was also 

multiplying—from less than one million head in 1850 to 

20 million head by 1890 (Stoddart and Smith 1943).

The fi rst national problem involving rangelands originated from the joint effects of land disposal and rapidly 

increasing livestock numbers. Large cumulative areas 

were awarded for railroad expansion and to states when 

they jointed the Union. Counting Alaska, 17 percent of 

the total state land area of the 30 states receiving land 

grants was obtained from the federal government; for the 

16 western states (Texas received no land), the fi gure was 

more than 91 million acres or almost 10 percent of their 

cumulative area (Public Land Law Review Commission 

1970). 

The Homestead Act of 1862 was followed by the 

Enlarged Homestead Act of 1909 (which allowed settlers 

to claim 320 acres) and the Stock Raising Homestead Act 

of 1916 (which provided 640 acres). In total, about 285 

million acres were claimed under the Homestead Acts 

(Ross 1984). All lands containing water and good grazing 

were occupied during this era. Even a section of land was 

insuffi cient for homesteaders to make a living throughout much of the West, however, so grazing started on the 

public domain (Carpenter 1981). 

Early Assessments

By 1934, the United States was facing a crisis on 

the public domain and, to a lesser extent, on National 

Forest reserves. The crisis was caused by the depression, 

drought, and confl icts between cattle and sheep interests 

Chapter 1: Introduction

in conjunction with severe depletion of the rangeland 

resource. States tried to regulate grazing within their borders, but the migratory nature of sheep operations compared to the spatially fi xed character of cattle ranches precluded solutions at the state level (Carpenter 1981). The 

result was passage of Senate Resolution 289 in the 74th 

Congress. The resolution read: 

“Whereas large parts of the western range have been 

subject to unrestricted use since settlement and are commonly believed to be more or less seriously depleted; and 

whereas the range resource constitutes one of the major 

sources of wealth to the Nation; and whereas the Department of Agriculture has through many years of research 

and of administration of the national forests accumulated 

a large amount of information on the original and present 

condition of the range resource, the factors which have 

led to the present condition, and the social and economic 

importance of the range and its conservation to the West 

and to the entire United States: Therefore, be it resolved 

that the Secretary of Agriculture be ... requested to transmit to the Senate at his earliest convenience a report 

incorporating this information, together with recommendations as to constructive measures.”

The Secretary of Agriculture (1936) subsequently submitted Senate Document 199, entitled “The Western 

Range.” In it, he highlighted several elements, including 

the following: 

• Of the 728 million acres of rangeland, more than 99 

percent “is available for livestock grazing.”

• Much of the range, especially in the Southwest, is in 

severely depleted condition (fi gure 1.1).

• A “maladjustment” to rangeland use has been the 

attempt to use more than 50 million acres for dryland farming.

• At least 589 million acres of rangeland is eroding 

excessively, thereby reducing soil productivity and 

impairing watershed function.

Box (1990) summarized fi ndings pertaining to rangeland depletion contained in the Senate Document 199 

report in two tables, reproduced here. They showed the 

National Forest reserves to be in better condition than private, state, and public domain lands (table 1.1), and that 

National Forest land was in an improving trend while the 

other three categories were in decline (table 1.2).

World War II interrupted conservation priorities in the 

United States. High priority was placed on producing red 

meat, wool, and leather for the war effort (Wasser 1942). 
6 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 1 Introduction

Table 1.1—Depletion of U.S. rangelands by ownership in 1935, taken from Senate Document 199 by Box (1990).

 Percent of Land by Depletion Class1

 Moderate Material2 Severe Extreme

Ownership (0–25%) (26–50%) (51–75%) (76–100%)

Federal

National Forests 45.5 40.0 12.0 2.5

Public Domain 1.5 14.3 47.9 36.3

Indian Lands 6.6 35.8 54.0 3.6

Other Federal 2.0 21.2 50.1 26.7

State and County 7.1 47.4 36.8 8.7

Private 11.7 36.9 36.4 15.0

1

 Referred to depletion of forage value in relation to “virgin” range.

2

 Substantial or noticeable. 

Table 1.2—Trends in range forage condition between 1905 and 

1935, taken from Senate Document 199 by Box (1990).

 Percent of Land by Trend Class

Ownership Improved Declined Unchanged

Federal

 National Forests 77 5 18

 Public Domain 2 93 5

 Indian Lands 10 75 15

 Other Federal 7 81 12

State and County 7 88 5

Private 10 85 5

Moderate Severe

Boundary of

range territory

Depletion

Material

Miles

0 300

Extreme

Fig. 1.1—Range depletion classes presented in Senate Document 199 (1936). Of the depletion classes, material (26–50 percent) and severe (51–75 percent) covered more than 70 percent 

of the entire “range area.” Nearly 120 million ac. was shown in 

the extreme (76–100 percent) depletion class. Of the 95 million 

ac. in the moderate (0–25 percent) depletion class, probably not 

more than half was estimated to be in “thoroughly satisfactory”

condition.

The next national assessment of rangelands, along with 

all other public lands not set aside for Indian reservations, 

was initiated in 1964 by the passage of Public Law 88-606, 

which established the Public Land Law Review Commission under the chair of Rep. Wayne Aspinall of Colorado. 

Its purpose was to review the effects of existing law and 

policy to determine whether U.S. public lands were providing “the maximum benefi t for the general public.”

When the Public Land Law Review Commission published its report to the President and Congress in 1970, 

the section of the report addressing rangelands emphasized the importance of forage coming from public lands 

(fi gure 1.2). Although public lands accounted for only 3 

percent of all forage consumed by livestock in the United 

States during the 1960’s, they supplied approximately 12 

percent of the forage in the western range states. In these 

states, forage from public lands was seen to play a signifi cant role in local economies, and increased funding to 

improve rangeland health was recommended. Cattle and 

sheep on public rangelands were seen as “an accepted 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 7

Introduction CHAPTER 1

Table 1.3—Principal conservation laws passed during the 1970’s that pertain to rangelands.

National Environmental Policy Act of 1969 Requires consideration of environmental impacts of Federal 

actions.

Wild Horses and Burros Protection Act Protects wild horses and burros.

Endangered Species Act of 1973 Provides a means for protecting/restoring threatened and 

endangered species.

Forest and Rangeland Renewable Resources Requires renewable resources assessment and program.

Planning Act of 1974 (RPA) 

Eastern Wilderness Act Promotes incorporating eastern public lands into the Wilderness 

system.

Federal Noxious Weed Act of 1974 Controls dissemination of noxious weeds.

Federal Land Policy and Management Act of 1976 (FLPMA) Retains remaining public domain lands in public ownership. Acts 

as organic act for the Bureau of Land Management.

National Forest Management Act of 1976 Amends and expands RPA.

Soil and Water Resources Conservation Act of 1977 Requires a recurring appraisal of all private lands and authorizes 

a national soil and water conservation program.

Forest and Rangeland Renewable Resources Expands research activities to encompass natural resource

Research Act of 1978 issues on a global scale.

Public Rangelands Improvement Act of 1978 Avows policy of monitoring and improving rangeland conditions; 

sets grazing fee policy.

Archaeological Resources Protection Act of 1979 Protects archaeological resources and sites on public and Indian 

lands.

Nevada 49%

Utah 28%

Arizona 27%

Idaho 17%

New Mexico 17%

Wyoming 16%

Oregon 13%

Montana 7%

Colorado 6%

California 4%

Washington 2%

Fig. 1.2—The importance of western public rangelands in the 

1960’s (Public Land Law Review Commission 1970).

feature of the scenery and environment” (Public Land 

Law Review Commission 1970).

From a legislative context, the 1970’s could be considered the decade of the environmental movement. The 

Wilderness Act was enacted in 1964. Then, starting in January 1970 with the National Environmental Policy Act of 

1969, no fewer than 12 major environmental laws affecting the conservation and management of U.S. rangelands 

were signed into law during the following 10 years (table 

1.3). Among such laws were the Resources Planning Act 

of 1974 (RPA) and the National Forest Management Act of 

1976 (NFMA) which called for a recurring assessment of 

America’s forest and rangeland situation.

The fi rst comprehensive assessment produced under 

the auspices of RPA/NFMA was published in 1980 (U.S. 

Department of Agriculture, Forest Service 1980). The 

chapter entitled “Range” defi ned rangeland in a manner 

that excluded improved pastures, cropland pasture, and 

grazed cropland because of they way these lands were 

managed—using agronomic instead of ecological means. 

Under this defi nition, 99 percent of the Nation’s 650 million acres of rangeland were identifi ed as being in the 

17 western states. About two-thirds of these rangelands 

were estimated to be under private ownership. 

The 1980 Assessment determined that 46 percent of 

rangelands in the conterminous 48 states were in fair to 

good condition. The authors noted the same general relationship between latitude and range condition reported 

in Senate Document 199 (Secretary of Agriculture 1936), 

except for Nevada which was deemed to be in better condition than expected (fi gure 1.1). 
8 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 1 Introduction

Projected demands for rangeland forage in the 1980 

Assessment were derived from the National Interregional 

Agricultural Projections (NIRAP) system, developed by 

the USDA Economic Research Service.1 The projections 

showed a logarithmic 40 percent increase between the 

years 1976 and 2030, from 213 million AUM’s to 300 

million AUM’s (fi gure 1.3). Determined linearly over 55 

years, such growth amounts to 0.62 percent per year. The 

principal factors driving the expansion in demand were 

forecasts for increased per capita demand for meat and 

increasing human populations (U.S. Department of Agriculture, Forest Service 1980). 

A forecasted 40 percent increase in demand for rangeland forage infl uenced agencies and some corporate landowners to look for ways to increase forage supplies without causing adverse effects on other uses. For example, 

the Northern Region of the Forest Service concluded that 

it could only meet this anticipated increase in demand 

by expanding uses of transitory range2 (Hardman 1979). 

Research relating to forage production on transitory range 

intensifi ed (Eissenstat and Mitchell 1983).

The 1989 RPA Range Assessment established a new 

standard for projecting the derived demand for grazed 

forage in the United States (Joyce 1989, Gee et al. 1992). 

It expanded the defi nition of grazed forage to include, 

in addition to rangeland, irrigated and non-irrigated pastures and grazed crop residues. Thus, the estimated forage 

supply for 1985 contained in the 1989 Assessment was 431 

300

Mil. animal unit months 275

250

225

200

1990 2000

Year

1970 2010 2020 2030

Historical demand supply relationship

Projected supply

Projected demand

1976

Fig. 1.3—Estimated increase in demand for rangeland forage, 

as presented in the 1980 RPA Assessment document (U.S. 

Department of Agriculture, Forest Service 1980).

1 Unpublished report: Quinby, William. 1989. Documentation of 

the NIRAP model. Washington, DC: U.S. Department of Agriculture, Economic Research Service, Natural Resource Economics 

Division. 29 p.

2 Transitory range is forest land that normally does not produce 

forage, but which does so for a limited number of years following forest harvest or fi re. See Basile and Jensen (1971), Lyon 

(1976), and Mitchell and Bartling (1991) for further discussion.

million AUM’s, substantially more than was projected for 

1985 in the 1980 Assessment. 

Also using the NIRAP system, but with revised estimates showing no increase in per capita meat consumption, the 1989 Range Assessment projected a linear 

increase in demand for grazed forage from 431 million 

AUM’s to 665 million AUM’s by the year 2040, a 54 

percent increase (fi gure 1.4). This is equivalent to an 

annual increase in forage demand of 0.79 percent per 

year, a higher rate than projected in the 1980 Assessment. 

Nonetheless, based upon an anticipated expansion in the 

rangeland land base of 5 percent and advances in technology, the 1989 Assessment concluded that increased 

demand for grazed forages by cattle and sheep could be 

almost entirely accommodated by an expanding contribution from private lands (Joyce 1989).

In the decade since the last RPA Range Assessment 

(Joyce 1989), our society’s values pertaining to public 

lands and natural resource management have begun to 

shift. Concepts such as sustainability, biodiversity, and the 

value of endangered species are having an increasingly 

larger infl uence upon management objectives (Salwasser 

et al. 1993). Policymakers, natural resource managers, and 

citizens, alike, are becoming aware of the importance of 

riparian zones (Chaney et al. 1990) and the cumulative 

effect caused by the spread of non-native plants (U.S. Congress, Offi ce of Technology Assessment 1993). Amenity 

resources associated with rangelands are starting to be 

valued (Peterson et al. 1988). The present Range Assessment, like those preceding it, is structured to address contemporary topics while continuing a baseline appraisal of 

the central theme for all range assessments—the demand 

for and supply of forage in the United States It examines 

Fig. 1.4—Projected (1990–2040) U.S. consumption of grazed 

forages by cattle and sheep, as reported in Joyce (1989).

700

Projected total

Projected cattle

Projected sheep

AUMs (millions)

1985 1995 2005

Year

2015 2025 2035

600

500

400

300

200

100

0
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 9

Introduction CHAPTER 1

Table 1.4—Montreal Process Criteria for the sustainable management of temperate and boreal forests (Coulombe 1995).

Criterion 1 Conserving biological diversity. (9 indicators)

Criterion 2 Maintenance of productive capacity of forest ecosystems. (5 indicators)

Criterion 3 Maintenance of forest ecosystem health and vitality. (3 indicators)

Criterion 4 Conservation and maintenance of soil and water resources. (8 indicators)

Criterion 5 Maintenance of forest contribution to global carbon cycles. (3 indicators)

Criterion 6 Maintenance and enhancement of long-term multiple socio-economic benefi ts to meet the needs of (19 indicators)

 societies. 

Criterion 7 Legal, institutional and economic framework for forest conservation and sustainable management. (20 indicators)

both anticipated supply and future demand from a different perspective, however. The U.S. Department of Agriculture has dropped its support of the NIRAP system 

and no longer maintains a model with a 50-year outlook. 

Therefore, an alternative approach, scenario analysis, was 

selected to project forage demand, and is reported elsewhere (Van Tassell et al. 1999). Supply projections are 

still tied to land use changes, but increases in rangeland 

resulting from conservation programs are no longer anticipated (Chapter 2, Extent of Rangelands) and advances 

in technology are not expected to signifi cantly change the 

forage supply per unit area (Chapter 4, Maintenance of 

Productive Capacity), except, perhaps, in the South (Van 

Tassell et al. 1999).

Four Assessment regions are used to describe data 

and other information on U.S. rangelands. They are the 

Pacifi c Coast (PC), Rocky Mountain (RM), North (NO), 

and South (SO) (fi gure 1.5). The Pacifi c Coast Assessment Region is further subdivided into the Pacifi c North 

(PN) and California (CA) Regions and the RM Assessment Region is subdivided into the Northern Rocky (NR) 

and Southwest (SW) Regions for some discussions.

Criteria and Indicators of 

Sustainability

As explained by Joyce (1989) in the last RPA Rangeland 

Assessment, determining the supply of natural resource 

outputs at a national level requires an evaluation of factors infl uencing their level of expression in the environment. One effort for identifying criteria and indicators 

(C&I) for the sustainable management of temperate and 

boreal forests at a national scale, the Montreal Process, 

has become widely recognized. Moreover, the concept of 

using C&I as factors for evaluating all facets of sustainability, including resource supplies, is receiving increasing acceptance (Corson 1996). 

The Montreal Process began with the 1992 United 

Nations Conference on Environment and Development, 

held in Rio de Janeiro in June 1992 (U.N. Conference on 

Environment and Development 1992). In addition to two 

treaty conventions, this conference produced three nontreaty agreements, including The Rio Declaration on Environment and Development and Agenda 21. The former 

presented a number of principles, one of which (Principle 

4) stated, “In order to achieve sustainable development, 

environmental protection shall form an integral part of 

the development process.” Specifi cally, the statement recognized that governments should be involved in devising 

scientifi cally credible C&I for the management, conservation, and sustainable development of forests. Agenda 21 

was designed as a scheme for attaining sustainable development (Johnson 1993). 

Following the Rio Conference, commonly called the 

“Earth Summit,” Canada convened an international seminar on Sustainable Development of Boreal and Temperate Forests. It was held in Montreal in September 1993. 

The seminar specifi cally addressed the establishment of 

C&I for sustainable management of temperate and boreal 

forests, and provided the conceptual basis for subsequent 

work on the subject. From that conference came a working group, whose business became known as the Montreal Process, that developed a set of C&I for temperate 

and boreal forests.

The Montreal Process has converged upon 7 criteria 

and 67 indicators for the sustainability of temperate and 

boreal forests, ultimately recognized in the Santiago Declaration of 1995 (Coulombe 1995) (table 1.4). The Forest 

Service, in collaboration with other agencies and interest 

groups, is undertaking a extensive program to develop 

and implement a C&I framework that can be integrated 

into Forest Service strategic planning, annual performance 

planning, national assessments, and forest resource planning, inventory and monitoring (USDA Forest Service 

1997).
10 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 1 Introduction

Work is presently in progress to evaluate the applicability of these C&I to rangelands (Mitchell 1999a). Notwithstanding the results of the evaluation, at least four 

criteria (Conserving biological diversity, maintenance of 

productive capacity of rangeland ecosystems, maintenance of rangeland health and vitality, and conservation 

and maintenance of soil and water resources) are expected 

to relate directly to rangeland resource outputs. Criterion 7 (Legal, institutional, and economic framework for 

rangeland conservation and sustainable management) 

is also briefl y considered in this report. The other two 

criteria contain indicators having important impacts on 

the supply and demand for rangeland resources; however, they are not considered directly. The relationships 

between the Montreal Process C&I are identifi ed, where 

appropriate, throughout this assessment document.

Fig. 1.5—USDA Forest Service regions.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 11

Introduction

Rangeland is a type of land that encompasses a number 

of major physiographic regions. It is characterized as 

those areas where the potential natural vegetation is comprised predominantly of grasses, grasslike plants, forbs, 

and shrubs, and where herbivory is an important ecosystem process (Frank et al. 1998). The Society for Range 

Management (Glossary Update Task Group 1998) defi nes 

rangeland as “land on which the indigenous vegetation is 

predominantly grasses, grass-like plants, forbs, or shrubs 

and is managed as a natural ecosystem.” Their defi nition 

further states that “rangelands include natural grasslands, 

savannas, shrublands, many deserts, tundras, alpine communities, marshes and meadows.” Rangelands are not 

limited to those areas grazed by domestic livestock, but 

include lands suitable only for wild herbivores. 

The area of rangeland constitutes a key indicator of 

conservation and sustainable management at a national 

scale (Mitchell et al. 1999a). If the term “forest” is replaced 

by “rangeland” in the Montreal Process criteria and indicators, the following indicators require estimates of the 

total area of rangeland in relation to classifi cation or land 

use practices:

Criterion 1: Conserving biological diversity

Indicator 1: Extent of area by rangeland type relative to 

total rangeland area.

Indicator 3: Extent of area by rangeland type in protected area categories.

Criterion 2: Maintaining the productive capacity of rangeland 

ecosystems

Indicator 10: Net area of rangeland available for forage 

production.

Criterion 4: Conservation and maintenance of soil and water 

resources

Indicator 19: Area of rangeland managed primarily for 

protective functions.

Criterion 6: Maintenance and enhancement of long-term multiple socio-economic benefi ts to meet the needs of societies

Indicator 35: Area of rangeland managed for general 

recreation and tourism in relation to the total area of 

rangeland.

Indicator 42: Area of rangeland managed to protect 

the range of cultural, social, and spiritual needs and 

values in relation to the total area of rangeland.

Chapter 2: Extent of Rangelands

World’s Rangelands

It is not a trivial task to accurately estimate the areal 

extent of any global land cover type (Bouwman 1990), 

especially one that crosses biome lines. There is general 

agreement, however, that rangelands occupy nearly half 

of the earth’s land area or about 65 million km2 (FAO 

1990). This total is reached as the sum of permanent pasture, open forest, and half of “other” lands such as desert 

and tundra (World Resources Institute 1986). The world’s 

rangeland base is roughly broken down as shown in table 

2.1. Slightly more than half, or 34 million km2

, is used for 

grazing livestock (Sere and Steinfeld 1996). An additional 

3 million km2 of cropland is devoted to cereal production 

for livestock feed (Steinfeld et al. 1997). (For comparison 

purposes, a square kilometer contains 247.1 acres.)

U.N. Food and Agriculture Organization (FAO) defi nes 

four general land-cover categories for global assessments; 

cropland, pasture, forest, and other. Various authors have 

compiled estimates of proportional changes in these cover 

classes (Werger 1983, World Resources Institute 1992). 

Although total world changes involving pasture land are 

relatively small, less than 0.1 percent per year, regional 

shifts are more pronounced (World Resources Institute 

1992). Niger, India, and Mongolia are losing pasture land 

at a much higher rate while South American countries, 

particularly Brazil, are gaining it (FAO 1987). Rangelands 

are typically being generated in the tropics as forests are 

cleared; while in more temperate regions, rangelands are 

being converted to cropland to satisfy needs of increasing 

human populations (Graetz 1994).

Current global demographic and environmental trends, 

however, could cause these slow changes in the rangeland base to become less stable and less predictable 

(World Resources Institute 1996). The human population 

Table 2.1—Global extent of major rangeland cover types. 

Land Cover Type Area ( 106

 km2)

Grassland 27

Shrubland 15

Woodland 8

Other (tundra, desert, forested) 15

Total possible rangeland 65

Grassland, shrubland, woodland estimates from Graetz (1994)

Total rangeland estimate from World Resources Institute (1986)
12 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 2 Extent of Rangelands

14

12

10

8

6

4

2

0

1850 1950 2050 2150 1900

Developing regions Developed regions

2000

Year

Billions

2100

Fig. 2.1—Estimated world population growth from 1800 to 2100 

AD (adapted from Clarke 1995).

Table 2.2—Population estimates in 1995 and projections (billion 

people) to 2050 by region (from Bongaarts 1998).

 Year

World Region 1995 2025 2050

Africa 0.72 1.45 2.05

Asia 3.47 4.82 5.49

Latin America 0.48 0.69 0.81

Europe 0.73 0.70 0.64

North America 0.30 0.37 0.38

Developing World 4.52 6.82 8.20

Developed World 1.17 1.22 1.16

World 5.69 8.04 9.37

is expected to increase to a range of from 8 billion to 

20 billion people by the year 2050 because of the demographic momentum of populations in developing countries with very high proportions in younger age classes 

(Demeny 1990). The median projection is for a population of about 10 billion people by mid-21st century 

(Clarke 1995) (fi gure 2.1). This low median results chiefl y 

from declining fertility rates that overcome continued 

decreases in mortality (Bongaarts 1998) (table 2.2). 

Urban sprawl consumes up to 5,000 km2 of arable land 

annually in developing countries (U.S. AID 1988). As a 

consequence, farming operations are systematically displaced onto more marginal lands, including those used 

for livestock grazing. A Canadian study, described by the 

World Resources Institute (1996), calculated that replacing the agronomic capability of farmland lost to urban 

expansion in Ontario required three times as much prairie grazing land to be converted to cropland. Countries 

with the highest annual increases in urban population 

tend to be the poorest of countries, mostly located in 

the tropics, or are wealthy oil states (fi gure 2.2). Temperate, mid-latitude countries with most of the world’s 

rangelands not only are characterized by annual growth 

rates of less than 4 percent, but already have signifi cant 

urban centers to act as the focal point of future expansion 

(Douglas 1994) (fi gure 2.2). 

One consequence of human population growth will be 

increasing pressure on basic natural resources, especially 

water. Since 1940, global withdrawals of fresh water from 

above-ground and below-ground sources have increased 

fi ve-fold (Clarke 1993). Many current patterns of water consumption are clearly unsustainable, although in the United 

States, aggregate withdrawals are expected to be fairly 

stable because of increased water use effi ciency (Brown 

1999). The effects of loss of available water to the rangeland base are uncertain: Irrigated farmland could convert 

to grazing land under some conditions, but semi-arid and 

arid grazing lands could become unsuitable for livestock 

production and, to a lesser extent, wildlife if aquifers are 

depleted to the point where wells and water holes protactedly dry up.

Mismanagement of water has potential to provide 

credible measures of desertifi cation, discussed below, at a 

national scale (Sharma 1998). The severity of desertifi cation may be determined from such hydrological indicators as runoff and reduced areas of water bodies.

Also more consequential than actual global rangeland 

conversion rates are the cumulative losses of soil quality, 

and hence productivity, because of erosion and desertifi cation (Schlesinger et al. 1990). Soil quality refers to 

the capacity of a soil to sustain biological productivity, 

maintain environmental quality, and promote plant and 

animal health (Doran and Parkin 1994). Unfortunately, 

the extent of erosion and desertifi cation on a world scale 

is inadequately understood (Graetz 1994). Some in the 

environmental conservation movement have derived estimates that approach two-thirds of all rangeland (Mabbutt 1984); however, the underlying assumptions are, to 

a large extent, speculative (Crosson 1995, Pimentel et al. 

1995). There is heightened scientifi c interest in whether 

some desertifi cation processes may amplify regional climatic changes (Verstraete and Schwartz 1991).

Oldeman et al. (1991) reported upon a UN-sponsored 

global assessment of human-induced soil degradation. 

They estimated that 19.6 million km2

 of land had been 

degraded around the world since the end of World War II, 

84 percent of it because of wind and water erosion. Of the 

total land eroded, 37 percent had been lightly eroded, 48 

percent had been moderately eroded, 15 percent had been 

heavily eroded, and 1 percent extremely eroded (table 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 13

Extent of Rangelands CHAPTER 2

Papua

New Guinea

Mozambique

Mauritania

Saudi Arabia

Libya Kuwait

Qatar

Djibouti

Swaziland

Botswana U.A.E.

Tanzania

Benin Chad Zambia Rwanda

Malawi Niger

Nigeria Bangladesh

Zimbabwe

Somalia

Afghanistan

Ethiopia

Malaysia

Thailand Zaire

Indonesia

Pakistan

Iran

Iraq

Jordan

Brazil

Vietnam

Sri Lanka

China

Kampuchea

India Fiji

Yugoslavia

South

Africa

Mexico

Norway

Cuba

Spain

Canada

Greece

Barbados

France

Japan

New Zealand

U.K.

Chile

Isreal

Venezuela

Australia

Singapore

U.S.A.

Austria

Germany

Belgium

U.S.S.R

Romania

Portugal

Ireland

Uganda

Kenya

Lesotho

OIL STATES

POOREST COUNTRIES

(Mainly Africa)

EUROPE

GROWING

ECONOMIES

SOUTHEAST

ASIA

Less successful

Rich

12

10

8

6

4

2

0

0 20 40

1990 urban population as a percentage of total

Average annual percentage increase in urban population, 1960-1990

60 80 100

Fig. 2.2—Increases in urban populations, by selected countries, in relation to urban proportion of total population (adapted from 

Douglas 1994).

2.3). The authors did not specify quantitative measures to 

their ordinal values of degradation, but if the proportions 

of productivity loss used by Dregne and Chou (1992) 

are assumed, one can derive an annual rate of productivity loss of approximately 0.5 percent per year since 1945 

(Crosson 1995). If true, soil productivity for the earth has 

declined by 22 percent during the past 50 years.

Nearly all deterioration of soil productivity in the 

United States is a result of water and wind erosion (fi gure 

2.3). The worst losses are in the Great Plains, with a rough 

dividing line between water and wind erosion occurring 

near 100° west longitude. As can be seen in a later section on the Conservation Reserve Program, these highly 

eroded lands form the core of farmland taken out of 

crop production and seeded predominantly to perennial 

grasses to mitigate excessive soil erosion.

The consequences of desertifi cation are cumulative. 

Oldeman et al. (1991) reported on unpublished comments 
14 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 2 Extent of Rangelands

Table 2.3—Global soil degradation by wind and water erosion 

(ha 106

). From Oldeman et al. (1991).

 Disturbance

Country (Land Area) Light Moderate Strong Extreme Total

North America (1,885)

 Wind 3 31 1 —1 35

 Water 14 46 — 60 —

South America (1,768)

 Wind 26 16 — — 42

 Water 46 65 12 — 123

Central America (306)

 Wind 1 22 23 — 46

 Water 1 4 — — 5

Africa (2,966)

 Wind 88 89 8 1 186

 Water 58 67 98 4 227

Asia (4,256)

 Wind 132 75 14 1 222

 Water 124 242 73 — 441

Europe (950)

 Wind 3 38 — 1 42

 Water 21 81 10 2 114

Australia/New Zealand (882)

 Wind 16 — — — 16

 Water 79 3 1 — 83

World (13,013)

 Wind 268 254 24 2 548

 Water 343 527 217 7 1,094

1

 Negligible land area.

by E.G. Hallworth in 1988 concerning soil loss from rangelands in Australia. Hallworth observed two “eras” of 

desertifi cation in the 20th century: the fi rst after sheep and 

cattle were introduced in large numbers, and the second 

during the second quarter of the century in association with 

extensive wind erosion. The land and vegetation became 

stable again after each era, but species composition had 

irreversibly changed and primary production may have 

also suffered. Wang and Hacker (1997) corroborated those 

observations by showing that severely degraded land in 

arid zones cannot be restored by optimal grazing management practices, nor even by compete removal of grazing.

Unfortunately, we lack explicit information that can 

verify the amount of change or degree of instability 

caused by desertifi cation (Wilson 1989). Existing assessment approaches relied, and largely still rely, upon equilibrium-based models of ecosystem behavior that do not 

adequately depict non-equilibrium rangeland dynamics 

(Westoby et al. 1989, Behnke and Scoones 1993).

Desertifi cation can occur as a consequence of more 

factors than soil erosion. The National Research Council 

(Committee on Rangeland Classifi cation 1994) recognized 

that nutrient cycling could hypothetically be as important to rangeland health as soil stability. Recent work at 

the Jornada Experimental Range in New Mexico not only 

has validated such a principle, but presented a conceptual model for linking a transition from desert grassland 

to shrubs, caused by re-distribution of soil nutrients, to 

climatic warming. The changes in world climate, in turn, 

can reinforce the transition process leading to regional 

desertifi cation (Schlesinger et al. 1990).

If irreversibility and declining productivity are assumed 

to be essential attributes of desertifi cation, then some of the 

world’s rangelands are in better condition than has been 

described above. One example is sub-Saharan Africa, where 

Tucker et al. (1991) showed that the northern boundary 

had recovered from long droughts over the previous two 

decades to its historic limits. The authors concluded that 

rangelands in the Sahel were in a state of dynamic fl ux 

rather than in continual decline because of desertifi cation. 

Milchunas and Lauenroth (1993) analyzed data from more 

than 200 areas around the world, and found percentage differences in above-ground production between grazed and 

ungrazed sites to be small where the ecosystem had evolved 

with grazing, particularly where productivity was low.

This alternative perspective is one of arid and semiarid rangelands being dynamic and resilient to perturbation when managed by established customs that allow for 

corrections, both spatially and temporally, during drought 

(Steinfeld et al. 1997). Under current environmental and 

social conditions, the essential element seems to be having 

suffi cient time for communities and cultures to react and 

adapt to non-equilibrium changes (Dunn 1997).

Land ownership reforms constitute a social non-equilibrium change on rangelands, and are serving to intensify 

rangeland degradation in many developing countries. Government policies pertaining to land ownership rights and 

restrictions can have a considerable impact on sustainability at a national scale, thus indicators in Criterion 7 of the 

Montreal Process (Legal, Institutional and Economic Framework for Forest Conservation and Sustainable Management) 

address the subjects of property rights and land tenure (U.S. 

Department of Agriculture, Forest Service 1997). 

Land transfers became important in the 1960’s when 

the World Bank and some governments began to capitalize livestock development projects (Herlocker 1998). 

The deleterious effects of privatization and other reforms 

were not anticipated by those planning and approving 

these projects; in fact, a number of negative outcomes 

did not show up until recently. For example, drilling of 

wells in central Asia led to increasing human populations, rangeland deterioration and, ultimately, decreases 

in national herd sizes of roughly 60 percent during the 

last 10 years (Laca and Suleimenov 1998). 
USDA Forest Service Gen. Tech. Rep. RMRS

–GTR–68. 2000. 15

Extent of Rangelands CHAPTER 2 Fig. 2.3—Human-induced soil degradation in the United States. (Source: Oldeman et al. 1991).
16 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 2 Extent of Rangelands

In Morocco, agricultural commodity and input cost 

subsidies associated with land reforms led to conversions 

from rangeland to cereal crop production, which, in turn, 

accelerated desertifi cation already taking place (Dobrowolski 1998). In Tanzania, the “villagization” process, 

combined with rapid socio-economic changes caused by 

population growth, has led to widespread rangeland degradation (East 1998). 

Nomadic customs in Tibet, Mongolia, and western 

China had promoted the maintenance of sustainable 

rangeland ecosystems for centuries. However, recent state 

privatization policies have caused graziers to settle in 

one place. These new practices are starting to transform 

rangelands on the Tibetan Plateau into less sustainable 

states (Miller 1998). A comparative examination of land 

use patterns in Mongolia versus Inner Mongolia (China) 

and Russian parts of Inner Asia has shown dividing rangeland into individual household pastures greatly reduced 

large-scale, nomadic pastoral movements. Resulting sedentary grazing systems required large quantities of hay, 

and the extensive use of heavy machinery to cultivate and 

store it is causing soil erosion and decreased productivity 

(Sneath 1998).

In summary, although the status of the world’s rangelands outside the United States is little changed since the 

last Assessment, most evidence points to signs of an accelerating rate of loss in rangeland productivity in developing countries outside the tropics; these losses are caused 

by increasing pressures from an expanding human population for the basic resources, food and water. These 

changes may have a limited short-term effect on U.S. 

rangelands, however, because of a lack of trade in red 

meat with and decreasing aid to developing countries 

(Fletcher 1992, Hook 1996).

U.S. Grazing Lands

Grazing land is any vegetated land that is grazed or 

that has the potential to be grazed by animals (Glossary 

Update Task Group 1998). Thus, grazing lands include 

rangeland, pastures, grazed woodlands, and grazed croplands. Information about the U.S. grazing land base comes 

from a number of sources. Regrettably, they are neither 

mutually exclusive nor collectively exhaustive (Zar 1996). 

The USDA Forest Service, for example, tracks acreages in 

grazing allotments, land that contains suitable rangeland, 

unsuitable rangeland, grazed forest land, and ungrazed 

forest land; however, rangelands not included in allotments are not considered. Therefore, the extent of rangeland must be determined indirectly, based upon more reliable and precise data describing other land categories.

The total land area in the conterminous United States 

is slightly less than 7.7 million km2 or about 1.9 billion 

acres. Alaska and Hawaii have another 360 million acres 

and 4 million acres, respectively. About 29 percent of all 

U.S. lands, or 660 million acres, is administered by federal 

civil and defense agencies (USDI Bureau of Land Management 1997a).

Disregarding Alaska and Hawaii, which have little 

effect on variations in the total U.S. rangeland base, the 

land used for livestock grazing gradually declined from 

the end of World War II until the 1980’s (USDA Economic 

Research Service 1997). In 1949, 1.0 billion acres were 

grazed in the continental United States (Wooten 1953). By 

1992, this area had dropped to 801 million acres (Daugherty 1995). Most changes have taken place on private 

lands because of shifts in land use, including conversion 

to cropland, urban expansion, improving forage productivity on private lands, and declines in the number of 

domestic grazing animals (Goddard et al. 1999).

The acreage devoted to grazing in 1992 included the 

following categories (USDA Economic Research Service 

1997):

 ac. 106

Grassland pasture and rangeland 589.0

Cropland used for pasture 66.8

Grazed forestland 145.0

The rangeland/pastures values are slightly less than the 

rangeland area reported by Joyce (1989). Her estimates 

were derived from model estimates, however, while the 

Economic Research Service estimates were based upon 

various agricultural surveys and the census of agriculture.

The distribution of rangeland in the United States, as 

described by Joyce (1989), can be described on the basis 

of Assessment Regions used in the Forest Service’s RPA 

reporting process:

Assessment Region and States Percent of Rangeland

Pacifi c Coast: WA, OR, CA 11

Rocky Mtns: ID, MT, ND, SD, 

WY, NE, NV, UT, CO, KS, AZ, NM 69

North: MO and states to N and E 1

South: VA to OK and south 19

Non-Federal Grazing Lands

The USDA Natural Resource Conservation Service 

(NRCS) inventories the Nation’s soil, water and related 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 17

Extent of Rangelands CHAPTER 2

resources found on non-federal lands every 5 years. This 

National Resources Inventory (NRI) is mandated by Congress (Nusser and Goebel 1997). In 1982, the NRI concentrated on determining the condition of the natural 

resource base, including rangelands (USDA Soil Conservation Service 1987). The 1992 NRI was designed to 

appraise changes to the non-federal resource base since 

1982 (Nusser et al. 1998). 

Privately owned rangeland accounted for 399 million 

acres of the total U.S. land base in 1992 (USDA Natural 

Resources Conservation Service 1996). Pastureland and 

grazed forestland added an additional 126 million acres 

and 63 million acres, respectively, giving a total non-federal grazing land base in the United States of 587 million 

acres (table 2.4). This total does not include Alaska or 

grazed croplands, neither of which are available from the 

NRI. Alaska was fi rst sampled in 1997.

Non-federal U.S. rangelands, like federal lands, are 

almost entirely west of the 95° meridian. The North 

(NO) Assessment Region contains only 130,000 acres of 

rangeland, all of which is in Missouri. In the South (SO) 

Assessment Region, nearly all rangeland is in Oklahoma 

(14 million acres) and Texas (94 million acres). Florida 

has more than 90 percent of the remaining 3.8 million 

acres of rangeland in the SO Assessment Region. From 

a physiographic perspective, Texas and Oklahoma are 

more similar to the Great Plains states included in 

the Rocky Mountain (RM) Assessment Region (Bailey 

1995).

NRI data indicate the United States lost a net area 

of 9.3 million acres of grazing land between 1982 and 

1992 (Goddard et al. 1999). This is from a 1982 land base 

of 606.5 million acres of non-federal rangeland, pastureland, and grazed forestland. The net losses and gains by 

state are shown in table 2.5. Assessment Regions had the 

following net losses in grazing land between 1982 and 

1992:

Table 2.4—Areas of non-Federal rangeland and pastureland, by Assessment Region, in relation to the total area of rural land, 1992 

(USDA Natural Resource Conservation Service 1995).

Acres 106

Assessment Grazed Total

 Region Rangeland Pastureland Forestland Total Rural Land

Pacifi c Coast1

 32.9 4.5 13.7 51.1 104.0

Rocky Mountains 253.6 15.7 19.9 282.2 453.3

North .1 39.9 9.2 49.3 359.5

South 112.0 65.4 20.1 197.5 468.7

Total 398.7 125.6 62.9 587.1 1,385.5

1

 Includes Hawaii, but not Alaska. The NRI did not sample Alaska until 1997.

Note: Grazed forestland sums come directly from the 1992 NRI data base.

Table 2.5—Net Loss (–) or Gain (+) of Non-Federal U.S. Grazing 

Lands1

 between 1982 and 1992, by state for those states changing by at least 100,000 acres. From Goddard (In Press).

State Acres 103 State Acres 103

SD –1,429 IL –330

TX –831 IN –291

ND –757 NY –284

CA –669 WI –267

FL –669 MI –254

MT –664 OH –185

IA –611 ID –154

CO –610 PA –121

MN –452 MS +500

NE –442 KY +264

KS –433 AL +212

AZ –382 GA +177

NM –351 VA +162

Note: States increasing or decreasing in grazing land less than 100,000 

acres are not shown.

1

 Includes rangeland, pastureland, and grazed forestland.

Assessment Region Acres 103

Pacifi c Coast 685

Rocky Mountain 5,400

North 3,100

South Not signifi cant

The SO Assessment Region had no signifi cant reduction in grazing land because fi ve states (MS, KY, AL, GA, 

and VA) recorded net conversions to grazing land from 

agricultural uses that totaled more than 1.3 million acres. 

Together with the other southern states, that was enough 

to compensate for the large losses of grazing land in Texas 

and Florida (table 2.5).
18 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 2 Extent of Rangelands

The land use to which non-federal grazing land was 

converted between 1982 and 1992 varied greatly with 

Assessment Region. Goddard et al. (1999) defi ned the 

three categories, developed land, agriculture and miscellaneous as follows: 

Category NRI Land-Use Classifi cation

Developed Land Large and small urban and built-up,

 roads and highways, railroads, farm 

 and ranch headquarters

Agriculture Horticulture, row crops, close-grown

 cropland 

Miscellaneous Conservation Reserve Program 

 lands, barren areas, marshland, 

 ungrazed forestland, water

In this categorization, farmsteads, ranch headquarters, 

and other rural home sites are included as developed 

land. Ranchettes and other rural home sites have been 

reported to be multiplying in several western states since 

1990 (Jobes 1993, Riebsame et al. 1996).

Most land coming out of grazing land between 1982 

and 1992 in the Pacifi c Coast (PC) Assessment Region and 

SO Assessment Region states was converted to developed 

land. In Texas, more grazing land went into development 

(1.055 million acres) than was lost, on a net basis, from 

the grazing land base. This could happen because Texas 

recorded a net increase in grazing land from agricultural 

land during the same time period (table 2.5). States in the 

SO Assessment Region that had a net gain in grazing land 

also lost land to development, but those conversions were 

more than offset by shifts from agricultural uses to grazing.

States in the RM Assessment Region primarily lost 

grazing land to agricultural uses (table 2.5). Plowing of 

rangeland for wheat and other close-grown crops was 

a recognized infl uence on the Great Plains during the 

1980’s. Laycock (1988) estimated that at least 4.5 million 

acres of native grassland was plowed in the Northern and 

Central Great Plains, alone. The causal factor was a large 

shortfall in world grain production in 1972 that induced 

the U.S.S.R. to purchase more than 700 million bushels of 

grain from the United States, including 25 percent of the 

total U.S. wheat crop (Sobel 1975). This and other sales, 

coupled with continued high demand, drove the price of 

wheat from $1.32 per bushel in July 1972 to a new high of 

$5.93 per bushel the following year. Prices for grains had 

weakened by 1987, but by then the fraction of farmland in 

crops stood at 41 percent, an all-time high (Crosson 1991). 

Plowing of rangeland may have lagged behind the outset 

of high wheat prices because many Great Plains farmers 

fi rst increased production by expanding onto idle lands 

(Crosson 1991). For example, the amount of land farmers 

were required to leave idle under provisions of the federal feed support program was reduced from 25 percent 

to 10 percent in 1973 (Sobel 1975).

The NO Assessment Region, as noted above, has no 

signifi cant rangeland. Accordingly, all net losses of grazing land came from pastureland and grazed forestland. 

Only one state in this assessment region, Iowa, lost more 

than a half-million acres. Another eight states lost between 

100,000 acres and 500,000 acres (table 2.5).

Non-Federal Rangeland

Nearly 8.6 million acres of non-federal rangeland was 

converted on a net basis to other uses between 1982 and 

1992 (Goddard et al. 1999). The decline amounted to roughly 

2 percent of the 1982 non-federal rangeland base of 409 million acres (USDA Natural Resources Conservation Service 

1995). No states gained rangeland, although it should be 

noted that lands put into the Conservation Reserve Program under provisions of Title XII of the 1985 Farm Bill 

were not categorized as rangeland in this report. The net 

losses by state are shown in table 2.6. Assessment Regions 

had the following net losses between 1982 and 1992:

Assessment Region Acres 103

Pacifi c Coast Not signifi cant

Rocky Mountain 5,100

North Not signifi cant

South 3,100

The NO Assessment Region contains by far the lowest 

amount of rangeland, only 130,000 acres (table 2.4). As a 

result, it is extremely diffi cult to detect even substantial 

changes for this region because of the low sampling population in relation to the NRI grid. 

As for all grazing lands, the land use to which nonfederal rangeland was converted on a net basis differed 

by Assessment Region. In the PC Assessment Region, 

about half of all rangeland was changed to agricultural 

lands with lesser amounts going to the miscellaneous and 

developed land categories. Rangeland changing use in 

the SO Assessment Region tended to be divided equally 

among developed land, agricultural land, and the miscellaneous category (table 2.6).

In the RM Assessment Region, which contains the most 

rangeland (table 2.4), net losses were dominantly shifted 

into agriculture to even a greater extent than for all grazing lands (table 2.6). The one outlier seems to be in New 

Mexico where for some reason the majority of its rangeland was transferred to the miscellaneous category. The 

likely reason for such a categorical conversion is the same 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 19

Extent of Rangelands CHAPTER 2

Table 2.6—Net conversion of non-Federal U.S. rangeland to development, agricultural and miscellaneous uses between 1982 and 

1992 for those states changing by at least 100,000 acres. From Goddard et al. (1999).

 Percent Converted to

 Change in

 rangeland Developed

Assessment Region/State (acres 103

) Land Agriculture1 Miscellaneous2

Pacifi c Coast

 WA 166 20 49 31

Rocky Mountains

 MT 977 03 89 08

 SD 824 02 91 07

 KS 655 06 68 26

 ND 635 06 79 15

 NM 477 23 16 61

 NE 419 05 75 20

 CO 390 34 78 –123

South 

 TX 1,181 55 16 29

 OK 1,002 07 38 55

 FL 877 30 43 27

1

 Includes pastureland.

2

 Includes grazed forest land and CRP land considered rangeland in the 1992 NRI.

3

 Negative percentage indicates transfer of land use into grazing.

as for all grazing lands in the RM Assessment Region: 

high demand for wheat and other grain crops.

The Conservation Reserve 

Program

The last rangeland assessment (Joyce 1989) described 

agricultural policy and conditions that led to conservation provisions in the Food Security Act of 1985 (1985 

Farm Bill). One of these provisions, The Conservation 

Reserve Program (CRP), has had a major infl uence on 

land cover in the United States (Mitchell 1988, Joyce et 

al. 1991). The CRP is a voluntary cropland retirement program that provides farm owners, operators, or tenants 

with an annual rental payment, plus an establishment 

cost-share, for establishing a permanent cover of grass, 

wildlife habitat, or trees. CRP was created to retire highly 

erodible or environmentally sensitive cropland from crop 

production for a period of 10 to 15 years.

The Food, Agriculture, Conservation, and Trade Act 

of 1990 extended the CRP and broadened its objective to 

include improving water quality and other environmental goals. In 1996, The Federal Agriculture Improvement 

and Reform Act amended the 1985 Farm Bill and confi rmed CRP’s new focus. 

An enrollment goal of at least 40 million acres was set 

by the 1985 Farm Bill. By the end of the 1989 crop year 

(9th signup) 29.8 million acres had been accepted into the 

program. This rapid expansion over a three-year period 

had several negative effects: A depletion of the native 

plant seed supply, leading to substitution of lower quality native and non-native species in many plantings; 

dramatic downturns for agricultural businesses in some 

areas that affected the well-being of local communities; 

and inadequate time for planning (Laycock 1991).

By 1993, and 12 signups after being implemented, 36.4 

million acres had been enrolled in the CRP (fi gure 2.4). The 

annual total rental payment at that time amounted to $1.8 

billion (USDA Farm Services Agency, unpublished report). 

Forty-fi ve percent of this land area was in the RM Assessment Region. Both the NO and SO Assessment Regions 

had about one-quarter of CRP lands, with the remaining 5 

percent situated in the PC Assessment Region. However, 

Oklahoma and Texas had more than 5.3 million acres of 

the South’s total. If these Great Plains states were added to 

the RM Assessment Region, the latter’s land in CRP would 

have amounted to 21.7 million acres, or 60 percent of all 

land enrolled through the 12th signup period (table 2.7). 

Much of the CRP lands in the SO Assessment Region outside of Texas and Oklahoma were planted to trees, signifying their importance as forestland rather than rangeland.
20 USDA Forest Service Gen. Tech. Rep. RMRS

–GTR–68. 2000.

CHAPTER 2 Extent of Rangelands Fig. 2.4—Distribution of CRP land in the United States through the 12th signup, 1993. Each blue dot represents 3,000 acres planted to other than trees (primar- ily grass), and each green dot represents 3,000 acres planted to trees. (Source: USDA Natural Resources Conservation Service, contract data, 1995).
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 21

Extent of Rangelands CHAPTER 2

Table 2.7—Land area enrolled in the Conservation Reserve Program through the 12th signup period, 1993, by Assessment Region 

and state. Area in acres 103

.

Pacifi c Coast Area Rocky Mtn Area South Area North Area

CA 187 CO 1,978 AL 573 DE 1

OR 531 ID 877 AR 260 IL 812

WA 1,047 KS 2,938 FL 135 IN 463

Total 1,765 MT 2,854 GA 706 IA 2,225

 NE 1,425 KY 451 MD 20

 NV 3 LA 147 ME 38

 NM 483 MS 842 MI 333

 ND 3,181 NC 151 MN 1,929

 SD 2,120 OK 1,193 MO 1,727

 UT 234 SC 278 NY 64

 WY 257 TN 476 OH 377

 Total 16,350 TX 4,150 PA 101

 VA 80 WI 746

 Total 9,442 Total 8,836

In late 1994, USDA decided to allow CRP participants 

to release their contracted land before the contract expiration date without penalty, with certain exceptions tied to 

parcels adjoining streams or other water bodies. 

Starting with the 13th signup, CRP contracts were 

designed to put greater emphasis on improving water 

quality and wildlife habitat. Bids were ranked using an 

environmental benefi ts index that gives preference to 

lands that are considered highly erodible, cropped wetlands, lands subject to scour erosion, and/or lands in 

national or state CRP priority areas. Overall, however, 

the amount of land under CRP contract declined to 33.0 

million acres by the end of 1996 and will have fallen 

to slightly more to 31.3 million acres in October 1999 

(Unpublished USDA press release). The 1996 Farm Bill 

limits the amount of land enrolled in CRP to 36.4 million 

acres, the land area under contract after the 12th signup.

Because of the priorities contained in the “new” CRP, 

distribution of enrolled lands has changed during the 

signups since 1996. A greater proportion of the contracts 

are being approved in areas affected by water erosion 

more than wind erosion which, in the Great Plains, is 

shifting the locus of points eastward (fi gure 2.5).

Much of the lands placed in the CRP have been planted 

to native rangeland species. However, they cannot be 

grazed by domestic livestock or hayed except during certifi ed emergencies such as droughts. Thus, these lands 

are not regarded as rangeland for classifi cation purposes 

by the NRCS. Diffi culties in converting former cropland 

fi elds to livestock production systems provide another 

reason for putting CRP lands in the miscellaneous category. For example, perimeter and interior fencing must 

be constructed, water developed, corrals and other livestock handling facilities built, and livestock purchased 

(Dodson and McElroy 1995).

Most economic data and landowner preference information indicate that farmers favoring retention of land 

under permanent cover do not have much land under 

CRP contract (Heimlich and Kula 1991). The area of CRP 

land ultimately converting to rangeland after all CRP 

contracts terminate will depend upon the long-term relative economics of crop and livestock production, including agricultural policy, and the kinds of values held by 

CRP participants (Heimlich 1995). 

No published research forecasts a signifi cant long-term 

increase in rangelands for livestock grazing because of the 

CRP. A comprehensive 1993 survey of CRP participants 

conducted by the Soil and Water Conservation Society 

concluded that 37 percent of land at the time would not 

be returned to crop production after the contracts expired, 

assuming that crop prices remained at 1993 levels. The 

survey also indicated that approximately 8.3 million acres 

enrolled in the CRP in 1993 would be used for pasture or 

grazing by cattle if contracts were not renewed (USDA 

Economic Research Service 1994). 

Another study, using data from the 1993 survey, raised 

doubts that so much land would be grazed (Dodson 

and McElroy 1995). The study noted, using state average 

stocking rates, that only 21 percent of enrollees would 

have suffi cient CRP land to stock 50 or more animal units 

on this land. Moreover, less than 40 percent of farms in 

the CRP reported having other pasture or cattle (only 14 

percent had more than 100 head of cattle), suggesting 

that a large majority of CRP contract holders lack both 

the expertise and equipment to handle livestock. Farmers who do have the capacity to expand livestock opera-
22 USDA Forest Service Gen. Tech. Rep. RMRS

–GTR–68. 2000.

CHAPTER 2 Extent of Rangelands Fig. 2.5—Distribution of percent change in Conservation Reserve Program lands from the 15th signup in March 1997 to the 16th signup in October–November 1997. (Source: USDA Natural Resources Conservation Service, contract data, 1995).
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 23

Extent of Rangelands CHAPTER 2

tions tend to be concentrated in the Central and Northern 

Great Plains (Dodson and McElroy 1995).

Research has demonstrated the effectiveness of CRP 

lands in enhancing wildlife habitat, especially for some 

ground nesting birds (Herkert 1998, Brady and Flather 

1998). Consequently, areas having economic incentives 

for wildlife habitat, such as in the Northern Great Plains, 

may primarily determine where CRP lands will be permanently converted to rangeland (Johnson and Schwartz 

1993).

A principal social intent for maintaining erodible farmland in a conservation program is to decrease soil erosion. According to USDA Natural Resources Conservation Service data, annual reductions in topsoil loss for 

land within the CRP amounted to 700 million tons by 

1993, or an average of 19 tons per acre (USDA Economic 

Research Service 1994). Two far-reaching unknowns will 

impact the future of CRP lands: (1) Whether the federal 

government will indefi nitely continue to fund a conservation program involving annual outlays of approximately 

$200 million for the public good of decreased soil erosion; 

and (2) if not, whether signifi cant numbers of contract 

holders in areas not having high wildlife values will opt 

to keep their land under permanent cover with decreased 

or no monetary remuneration for doing so. 

National Forest System Lands

The extent of rangelands on National Forest System 

(NFS) lands is diffi cult to ascertain. The 1989 Assessment 

estimated the total to be 40.66 million acres. This broke 

down by Assessment Region to (USDA Forest Service 

1989):

Assessment Region Rangeland Area (Acres 103

)

Pacifi c Coast 10,813

Rocky Mountain 29,785

South None

North 65

Forest Service estimates of NFS rangeland are presently 

defi ned on a different basis, making any comparisons 

with the 1989 data infeasible. They are enumerated as the 

area of land with range vegetation, either upland or riparian, within grazing allotments having range vegetation 

management objectives. The Range Management Staff, 

Washington Offi ce, USDA Forest Service approximated 

the following extent of such lands, by Assessment Area, 

for 1997:

 Upland Riparian

 Rangeland Rangeland 

 Area Area

Assessment Region (Acres 103) (Acres 103)

Pacifi c Coast 17,349 785

Rocky Mountain 53,763 1,576

South 1,169 60

North 65 <1

All NFS Lands 72,346 2,421

The discrepancy between the 1997 estimates and those 

contained in the 1989 RPA Assessment is primarily attributed to differences in the way individual national forests 

determined rangeland area in 1997. Some Forests, for 

example, included all lands within the borders of range 

allotments, regardless of whether they were unsuitable 

for grazing because of timber cover (Personal communication, Rita Beard, Range Management Staff, Washington Offi ce, USDA Forest Service). Thus, it is likely that 

the extent of rangelands on NFS lands is not signifi cantly 

different from what was reported in 1989 (USDA Forest 

Service 1989). National Resources Inventory data disclose that all federal lands together increased by only 

3.29 million acres, or 0.5 percent of the federal land base, 

between 1982 and 1992 (USDA Natural Resources Conservation Service 1995). Therefore, NFS lands, including 

rangelands, have not increased signifi cantly during the 

past 20 years.

Rangelands Managed by the 

Bureau of Land Management

The Bureau of Land Management (BLM) has jurisdiction over 137 million acres within grazing districts, 

including Land Utilization Project lands transferred to 

the Department of Interior from the Department of Agriculture by various executive orders. It is responsible for 

an additional 108 million acres of public land that are not 

included in grazing districts, 87 million acres of which 

are located in Alaska, along with 19 million acres of 

other reserved land (USDI Bureau of Land Management 

1997b). 

Lands within grazing districts are managed according 

to the Taylor Grazing Act of 1934, as modifi ed by the Federal Land Policy and Management Act of 1976 (FLPMA). 

Lands outside of grazing districts are managed solely 

under FLPMA, which gave BLM a unifi ed legislative 
24 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 2 Extent of Rangelands

mandate to manage all public lands—lands that were to 

“be retained in Federal ownership.” There are minor differences between how the two categories of land are managed; for example, grazing permits are awarded on rangelands within grazing districts, while leases are allowed 

on rangelands outside of grazing districts. Nonetheless, 

there is little difference between how permits and leases 

are administered.

Nearly all BLM public lands not classifi ed as reserved, 

both those within grazing districts and those without, 

are deemed to be rangeland (Personal communication, 

Thomas C. Roberts, Jr., Washington Offi ce Range Management Staff, USDI Bureau of Land Management). Public 

lands outside of Alaska sum to 155.4 million acres (table 

2.8), or 6.6 million acres more than was attributed to BLM 

rangelands in the 1989 RPA land base assessment document (USDA Forest Service 1989). Assuming the accuracy 

of the 1989 estimate, that means more than 95 percent of 

BLM public lands are classifi ed as rangeland.

Essentially all BLM rangelands are found in the PC 

and RM Assessment Regions. Public lands outside of 

grazing districts are limited to 16,000 acres in seven states 

in the SO Assessment Region and less than 9,000 acres in 

two states, Minnesota and Wisconsin, in the NO Assessment Region. About three-fourths of all BLM lands can 

be found in the Intermountain region of the western and 

southwestern United States (table 2.8).

The extent of rangeland under BLM control is stable 

and is expected to be so in the future. Between 1986 and 

1996, the amount of land within grazing districts diminished by 1.5 percent from 136.8 million acres to 134.8 million acres. Concomitantly, the land area outside of grazing districts, excluding Alaska, decreased from 26.1 milTable 2.8—Area of public lands under the management of USDI Bureau of Land Management for the Pacifi c Coast and Rocky Mountains Assessment Regions, 1996. Area in acres 103

.

 Pacifi c Coast Rocky Mountains

 

State Grazing Districts Other Public Lands State Grazing Districts Other Public Lands

CA 1,725 7,380 AZ 10,093 1,517

OR 12,459 578 CO 6,776 480

WA None 362 ID 10,737 423

Total 14,184 8,320 MT 4,940 1,151

 NE None 7

 NV 44,493 3,137

 NM 11,113 1,356

 ND None 59

 SD None 272

 UT 21,159 None

 WY 11,274 3,916

 Total 120,585 12,318

lion acres to 20.7 million acres, primarily because of large 

transfers totaling 5.4 million acres in California, including 

the 1.6 million acre Mojave National Preserve created by 

the 1994 California Desert Protection Act.

Outlook for the U.S. Rangeland 

Base

Two antithetical processes, consolidation and subdivision, are infl uencing the nature of the U.S. rangeland base, 

and nothing shows on the horizon that can be expected to 

signifi cantly alter this pattern over the next 50 years.

Consolidation is the process of concentrating private 

rangeland among fewer and fewer holders. Today, less than 

2 percent of farmland owners possess more than one-third 

of U.S. farmland (USDA Economic Research Service 1994). 

Between 1988 and 1997 the number of farms in the United 

States decreased from 2.20 million to 2.06 million, while 

the average farm size increased from 452 acres to 471 acres 

(USDA National Agricultural Statistics Service 1998). Since 

the mid-1930’s the decline in farm numbers has approximated an inverse exponential curve, meaning that the rate of 

decrease will presumably lessen in future years (fi gure 2.6).

Farms and ranches are subdivided into smaller units 

for multiple reasons, but primarily to allow children of 

farmers to have their own land or to raise capital to pay 

debt. Farmland subdivided for economic purposes may 

or may not remain in that use.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 25

Extent of Rangelands CHAPTER 2

Table 2.9—States with the greatest population growth rate 

during the period 1990 to 1994. From Riebsame et al. (1997).

 Population growth

State (Percent)

1. Nevada 21.2

2. Idaho 12.5

3. Arizona 11.2

4. Colorado 11.0

5. Utah 10.7

6. Alaska 10.2

7. Washington 9.8

8. New Mexico 9.1

Table 2.10—Change in economic sales class of farms and 

ranches in the 11 western states1

 (where most rangelands 

occur) plus Alaska and Hawaii between 1995 and 1997. From 

USDA National Agricultural Statistics Service (1998).

 Economic sales class

 Number of farms 103

Year <$10,000 $10,000–99,999 ≥$100,000 Total

1995 126.6 100.0 47.7 274.3

1996 130.7 96.2 50.2 277.1

1997 135.1 92.1 51.9 279.1

1

 AZ, CA, CO, ID, MT, NV, NM, OR, UT, WA, WY

Fig. 2.6—Trends in the number of U.S. farms and amount of farmland between 1900 and 1990. A farm is any establishment from 

which $1,000 or more of agricultural products, including livestock, 

are sold or normally would be sold during a given year, and farmland is all land used to produce those agricultural products.

1900

0

Farms (millions)

Farmland (billion acres)

2

4

6

10 20 30 40

Year

50 60 70 80 90

In some scenic parts of the rangeland West, pastureland and rangeland value is appreciating so rapidly that 

ranchers have come under extreme economic pressure 

to subdivide their lands for rural homes or “ranchettes.”

Such appreciation has been fueled by a signifi cant immigration into the mountain states of the RM Assessment 

Region since 1990, resulting in part from an expanding 

high-tech, professional service industry that is not physically tied to metropolitan centers (Riebsame et al. 1997). 

The fi ve most rapidly growing states between 1990 and 

1994 were from this region (table 2.9). Ranchettes are commonly developed in parcels of 35 acres or slightly larger, 

sometimes to circumvent local and county zoning regulations. In semi-arid foothill locations, 35 acres are often 

inadequate for commercially raising livestock, yet constitute too large a block of land to be recognized as being 

a built-up landscape by the NRI or remotely sensed classifi cation systems. Thus, the extent of subdivisions for 

rural homes is mostly undetermined. The spatial distribution of successful and unsuccessful developments for 

rural homes across all grazing lands also has not been 

described.

Both consolidation and subdivision can be seen by 

examining the changing distribution of number of farms 

and ranches by farm economic sales class over time. For 

example, smaller working farms and ranches in the 13 

western states (where most rangelands occur), including 

Alaska and Hawaii, decreased while those making less 

than $10,000 or more than $100,000 increased between 

1995 and 1997 (table 2.10). The increasing number of small 

“hobby” farms that have farm-related incomes between 

$1,000 and $10,000 is probably causing the rate of farm 

decline shown in fi gure 2.6 to be fl atter than a true negative exponential curve.

To summarize, the amount of grazing land and rangeland in the United States is expected to continue slowly 

declining over the next 50 years. However, land use shifts 

away from grazing use will be much greater in areas of 

more rapid population increases and concomitant appreciation in land values. Whether states in the Rocky Mountains and their foothills will continue to dominate locations of high immigration by the year 2050 is unknown. 

Research supporting the forage demand projections, however, suggests that changes in land use will decrease the 

amount of land available for grazing to a greater extent 

in a consolidated PC and RM Assessment Region than 

either the NO or SO Assessment Regions throughout the 

foreseeable future (Van Tassell et al. 1999).

USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 27

Introduction

Indicators of rangeland health vary between those 

applying to national-level criteria and those that apply to 

management-unit or site-specifi c criteria. Classical conventions for assessing rangeland health have dealt exclusively with the latter. In fact, at least two indicators 

of range condition at a site level are manifested in criteria other than ecosystem health and vitality (Criterion 

3) of the Montreal Process (U.S. Department of Agriculture, Forest Service 1997): The extent of area by successional stage appears in Criterion 1, conserving biodiversity (Flather and Sieg 2000), and area with signifi cant soil 

erosion appears in Criterion 4, conservation and maintenance of soil and water resources (Neary et al. 2000). This 

chapter deals primarily with local measures of rangeland condition, although the chapter summary attempts 

to synthesize them into a national-level assessment of 

rangeland health.

The decade since the last technical document supporting the RPA Assessment (Joyce 1989) has seen rapid 

advances in how rangelands have been viewed from 

a condition or health context. Early management concepts of range condition (Dyksterhuis 1949) were based 

upon the Clementsian equilibrium theory of retrogression caused by overgrazing, and by secondary succession 

to a stable climax following removal of the grazing disturbance. Although the Forest Service had incorporated 

soil condition (erosion and erodibility) into its protocol 

for assessing range condition by the early 1950’s (Ellison 

et al. 1951), vegetation condition continued to be differentiated following the Clementsian model (Parker 1954).

The abstraction of four range condition classes (excellent, good, fair, poor) remained ingrained into inventory 

and assessment processes of U.S. land management agencies (DeGarmo 1992), even after scientifi c evidence began 

challenging the Clementsian vision of succession (Slayter 1975, Wilson and Tupper 1982, Archer 1989). Consequently, the last RPA technical document was obliged to 

report rangeland health in these terms for all agencies 

(Joyce 1989).

The seminal alternative hypothesis for non-equilibrium vegetation dynamics on disturbed rangelands was 

advanced by Westoby et al. (1989). At the same time, ecologists in various disciplines began to question whether 

ecosystem behavior under stress should be described only 

on the basis of vegetation responses (Rapport et al. 1985). 

The manner in which the range condition concept evolved 

Chapter 3: Rangeland Health

from a simplistic, universally accepted model to the present changing, complex situation has been described by 

Joyce (1993).

In 1989, the Board on Agriculture of the U.S. National 

Research Council convened a Committee on Rangeland 

Classifi cation to examine the scientifi c basis of methods 

used by the USDA Forest Service, USDA Natural Resources Conservation Service (NRCS) (then, called Soil 

Conservation Service), and the USDI Bureau of Land Management (BLM) to classify, inventory, and monitor rangelands. The Committee fulfi lled its assignment through 

meetings, fi eld investigations, and interviews. Their report 

was issued as a book in 1994 (Committee on Rangeland 

Classifi cation 1994). The report proposed a new paradigm for assessing rangeland health—one based upon 

non-equilibrium, state-and-transition models of succession that focus on ecosystem function rather than ecosystem state (plant community composition). Three major 

criteria suggested were soil stability and watershed function, distribution of nutrient cycling and energy fl ow, and 

recovery mechanisms.

At about the same time, the Society for Range Management assembled a Task Group on Unity in Concepts 

and Terminology to seek agency commonality in technology and methodology relating to rangeland condition 

and trend. The Task Group report called for making sustainability the fundamental goal of rangeland management (Task Group on Unity in Concepts and Terminology 

1995). They defi ned sustainability in terms of maintaining 

soil productivity. Therefore, the primary goal of management would be to keep wind and water erosion to a rate 

below that where soil loss reduces the productive potential for a site.

Unfortunately, the scientifi c advances described above 

have not yet been incorporated into national data sets 

of rangeland condition. The Western Regional Research 

Coordinating Committee on Rangeland Research concluded that thresholds for sustainability can only be 

determined through monitoring benchmarks representing well-managed ecological sites in arid and semi-arid 

areas (West et al. 1994). Relict areas can be situated in 

topographic features that isolate them from different disturbance patterns than the surrounding landscape, especially with reference to wildlife grazing and fi re (West 

1991a). 

Nor are data sets of rangeland condition standardized 

in a manner that allow comparisons among federal agencies. This chapter will assess condition as reported by the 

NRCS for non-federal rangelands and by the Forest Service and BLM for federal lands under their jurisdiction. 

In 1997, these three primary land management agencies 
28 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

entered into a memorandum of understanding to establish a Federal Interagency Rangeland Health Committee 

to standardize the methodology for inventorying, monitoring, and assessing the status of rangeland health on all 

U.S. lands. Thus, future range assessments should have 

more opportunity to describe the rangeland health situation at the management unit level in a coordinated and 

consistent way.

Two factors relating to trees have affected rangeland 

condition during the 20th Century. They are encroachment of brush and woodlands onto grasslands, and the 

decline of quaking aspen (Populus tremuloides) (Bartos and 

Campbell 1998). Both are seen as rangeland sustainability 

issues and are discussed in this chapter.

Finally, the spread of non-indigenous plants onto 

U.S. rangelands has had a considerable deleterious effect 

on sustainability (U.S. Congress, Offi ce of Technology 

Assessment 1993). The area of forest (or rangeland) 

affected by processes or agents beyond the range of historic variation, including exotic species, is an indicator 

of ecosystem health in the Montreal Process, so trends 

of unwanted non-indigenous rangeland plants are also 

examined separately.

Condition of Non-Federal 

Rangelands

Condition of non-federal rangelands was reported in 

the 1989 Assessment (Joyce 1989) from data collected 

during the 1982 National Resource Inventory (NRI) 

(USDA Soil Conservation Service 1990). The NRI was 

directed by the 1972 Rural Development Act to provide 

Congress with current information concerning the status 

and trends of soil, water, and related resources on nonfederal lands. The NRI is repeated every fi ve years using 

a stratifi ed, two-stage random area sample of primary 

sampling units (PSU). By 1982, more than 300,000 PSU’s 

had been established. The second sampling stage consists of three or less permanent sample points situated 

within each PSU according to a restricted sampling process (Nusser and Goebel 1997).

In 1992, a study supplementing the 1992 NRI was conducted to estimate range condition and trend, as well as 

other indicators of rangeland health, in the 17 conterminous western states plus Florida and Hawaii. The supplemental study obtained data from fi eld sampling techniques that followed nearly the same procedures for estimating condition and apparent trend as was carried out 

in the 1982 NRI. The results of the supplemental study, 

which were not included in the 1992 NRI (USDA Natural 

Resources Conservation Service 1995), have not been published. Those results can still be used, however, to crudely 

assess rangeland health over the 10 years between these 

two sampling periods by comparing state range condition summaries with those in the 1982 NRI.

Both the 1982 NRI and 1992 supplemental study evaluated range condition on the basis of species composition following the Dyksterhuis (1949) model. Species 

composition, estimated on a biomass basis, is compared 

to a typical “climax” plant community for the range site 

being rated. A range site, now called an ecological site, is 

defi ned as “a kind of land with specifi c physical characteristics which differs from other kinds of land in its ability to produce distinctive kinds and amounts of vegetation and in its response to management” (Task Group on 

Unity in Concepts and Terminology 1995). 

Pacifi c Coast Region

It is infeasible to estimate trend in rangeland condition for the entire Pacifi c Coast (PC) Assessment Region 

because data were not obtained in California during 1992. 

Of the 17 million acres of non-federal rangeland in California that year, one-half million acres had been seeded 

to non-native species, more than 5 million acres were on 

sites for which no condition guides had been written, and 

11 million acres were annual grasslands. The 1982 estimate for range condition in California is shown in table 

3.1.

Rangeland conditions in Washington and Oregon are 

very similar. The 1992 estimates show at least one-third 

of the land is in excellent or good condition and another 

one-third is in fair condition (table 3.1). Because measured 

trend is improving, range condition on private lands 

in the Pacifi c Northwest is judged to be in an upward 

trend.

Rocky Mountain Region

For purposes of discussing rangeland condition, the 11 

states in the Rocky Mountain (RM) Assessment Region 

are divided into the states dominated by mountains, 

valleys, and cold desert steppes (mountain states) and 

the states exclusively found on the Great Plains (plains 

states).

Condition of non-federal rangeland in the mountain 

states was characterized as improving more slowly than 

in other western states, with only 1 acre in 20 being in 

excellent condition. However, only 1 acre in 10 was in 

poor condition in 1992, indicating at least 80 percent of 

the land was clustered into the two middle condition 

categories, good and fair. This ranking had not changed 

much since 1982, although trends subjectively appeared 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 29

Rangeland Health CHAPTER 3

Table 3.1—Range condition on non-federal rangelands, 1982 

and 1992: Pacifi c Coast Assessment Region (acres 103

 and 

percent of total area for which condition ratings were applied).

 Year

State Condition Class 1982 1992

California Excellent 29 2% NA 

 Good 473 31%

 Fair 613 40%

 Poor 434 28%

Oregon Excellent 226 2% 625 7%

 Good 1,813 20% 2,404 27%

 Fair 3,486 38% 3,073 34%

 Poor 3,731 40% 2,855 32%

 Other1

 136 418

Washington Excellent 629 11% 689 13%

 Good 1,169 21% 1,567 29%

 Fair 1,816 33% 1,617 30%

 Poor 1,933 35% 1,542 28%

 Other 90 61

Total Excellent 855 6% 1,314 9%

 Good 2,982 20% 3,971 27%

 Fair 5,302 36% 4,690 33%

 Poor 5,664 38% 4,397 31%

 Other 226 479

NA = Data not available.

1

 “Other” indicates land for which range condition guides are not available.

Table 3.2—Range condition on non-federal rangelands, 1982 

and 1992: Rocky Mountain Assessment Region, mountain states 

(acres 103

 and percent of total area for which condition ratings 

were applied ).

 Year

State Condition Class 1982 1992

Arizona Excellent 518 2% 650 2%

 Good 4,923 16% 8,446 27%

 Fair 16,574 54% 15,886 50%

 Poor 8,832 28% 6,661 21%

 Other1

 101 584

Colorado Excellent 333 1% 371 2%

 Good 5,803 24% 9,399 41%

 Fair 14,012 58% 10,462 45%

 Poor 4,033 17% 2,872 12%

 Other 41 433

Idaho Excellent 323 5% 242 4%

 Good 2,187 35% 2,187 35%

 Fair 2,566 40% 2,420 39%

 Poor 1,255 20% 1,357 22%

 Other 402 462

Montana Excellent 5,028 13% 3,905 11%

 Good 17,272 46% 17,233 47%

 Fair 12,605 34% 14,048 38%

 Poor 2,727 7% 1,361 4%

 Other 185 288

Nevada Excellent 239 3% 386 5%

 Good 2,674 35% 2,913 40%

 Fair 4,027 53% 3,208 44%

 Poor 659 9% 780 11%

 Other 309 567

New Mexico Excellent 659 2% 591 2%

 Good 12,262 30% 14,314 36%

 Fair 22,617 55% 21,227 53%

 Poor 5,422 13% 3,645 9%

 Other 22 15

Utah Excellent 155 2% 303 3%

 Good 1,724 21% 2,188 23%

 Fair 4,027 48% 4,322 46%

 Poor 2,451 29% 2,563 27%

 Other 132 46

Wyoming Excellent 331 1% 1,853 7%

 Good 11,610 43% 12,047 46%

 Fair 13,988 52% 10,761 42%

 Poor 976 4% 1,308 5%

 Other 10 46

Total Excellent 7,586 4% 8,301 5%

 Good 58,455 32% 68,727 38%

 Fair 90,416 50% 82,334 46%

 Poor 26,375 14% 20,547 11%

 Other 1,202 3,069

1

 “Other” indicates land for which range condition guides are not available.

to be slightly upwards (table 3.2). Montana seemed to 

stand alone in having vegetation distributions approaching later seral stages (table 3.2).

Non-federal lands in the plains states were in substantially better rangeland condition than the mountain states 

in 1992, with surprisingly large movements from good to 

excellent condition during the 10 years since 1982 (table 

3.3). North Dakota was an anomaly, perhaps responding 

in part to the recent accelerated spread of weeds in the 

northern plains (Bangsund and Leistritz 1991). 

The overall rangeland condition on non-federal lands 

for the RM Assessment Region is shown in table 3.4.

South Region

Only three states in the South (SO) Assessment Region 

were sampled during the 1992 supplemental study—Florida, Oklahoma, and Texas. On the other hand, these three 

states contains approximately 62 percent of all grazed 

AUM’s in the SO Assessment Region (table 3.5). The 

states, consequently, somewhat refl ect overall conditions 

in the region by their weighted importance.
30 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

Table 3.3—Range condition on non-federal rangelands, 1982 

and 1992: Rocky Mountain Assessment Region, plains states 

(acres 103

 and percent of total area for which condition ratings 

were applied).

 Year

State Condition Class 1982 1992

Kansas Excellent 966 6% 1,820 12%

 Good 8,092 48% 6,934 44%

 Fair 6,122 36% 5,832 37%

 Poor 1,666 10% 1,137 7%

 Other1

 63 0

Nebraska Excellent 2,189 9% 4,501 20%

 Good 12,636 55% 10,527 47%

 Fair 7,110 31% 6,303 28%

 Poor 1,069 5% 1,178 5%

 Other 92 160

North Dakota Excellent 1,524 14% 1,130 11%

 Good 6,295 57% 5,096 51%

 Fair 2,761 25% 2,984 30%

 Poor 368 3% 872 8%

 Other 0 243

South Dakota Excellent 1,877 8% 3,804 17%

 Good 13,716 60% 10,736 49%

 Fair 6,486 29% 6,687 31%

 Poor 704 3% 566 3%

 Other 1 140

Total Excellent 6,556 9% 11,255 16%

 Good 40,739 55% 33,293 48%

 Fair 22,479 30% 21,806 31%

 Poor 3,807 5% 3,753 5%

 Other 156 543

1 “Other” indicates land for which range condition guides are not available.

Table 3.4—Range condition on non-federal rangelands, 1982 

and 1992: Rocky Mountain Assessment Region (acres 103

 and 

percent of total area for which condition ratings were applied).

 Year

 Condition Class 1982 1992

 Excellent 14,142 5% 19,556 8%

 Good 99,194 39% 102,020 41%

 Fair 112,895 44% 104,140 41%

 Poor 30,182 12% 24,300 10%

 Other1

 1,358 3,612

1 “Other” indicates land for which range condition guides are not available.

Table 3.5—Forage consumption estimates in the Southern 

Assessment Region, based upon the January 1993 inventory 

of beef cattle. Source: USDA National Agricultural Statistics Service (1995).

Region Animals 103

 AUM’s 103

FL, OK, and TX 14,560 174,720

Southern Assessment Region 23,467 281,604

Percent of total 62%

Florida ranks as having more non-federal rangeland 

unlike its associated climax communities than any other 

state in the conterminous U.S. (table 3.6). More than onehalf of Florida rangeland was estimated to be in poor condition in 1992 by the NRCS supplemental study, and the 

proportion of land in poor condition increased by approximately 350,000 acres during the prior decade. No scientifi c basis has been proposed for such a rapid decline, but 

weed infestations, expansion of urban areas and attendant lowering of freshwater aquifers, and regulation of 

controlled fi res may be adversely impacting the physical 

environment (Mullahey et al. 1994, Collins and Freeman 

1996, Breininger and Schmalzer 1990).

Texas’ non-federal rangelands were more degraded, 

according to the 1992 supplemental study, than any other 

Great Plains state (table 3.6). Since federal lands comprise 

less than 2 percent of Texas, these estimates essentially 

apply to the entire state (USDI Bureau of Land Management 1997a).

Collectively, non-federal rangeland in the three states 

in the SO Assessment Region are in earlier successional 

status than either the PC or RM Assessment Regions 

(table 3.6).

North Region

There are only 130,000 acres of native rangeland in the 

North (NO) Assessment Region, nearly all of it in Missouri (table 2.4). This does not constitute an adequate 

land base to warrant discussion in a national assessment. 

Condition of Federal Rangelands

The condition of rangelands administered by the U.S. 

government is a subject of great interest and contention. 

Grazing is the most widespread land management practice on western public lands, and the results of public 

grazing policy, both past and present, are coming under 

increasing scrutiny (Council for Agricultural Science and 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 31

Rangeland Health CHAPTER 3

Table 3.6—Range condition on non-federal rangelands, 1982 

and 1992: Southern Assessment Region (acres 103

 and percent of total area for which condition ratings were applied).

 Year

State Condition Class 1982 1992

Florida Excellent 25 1% 19 1%

 Good 273 7% 171 5%

 Fair 1,831 49% 1,196 35%

 Poor 1,640 43% 2,003 59%

 Other1

 35 78

Oklahoma Excellent 907 6% 1,749 12%

 Good 3,601 24% 4,492 32%

 Fair 7,639 51% 5,835 42%

 Poor 2,904 19% 1,951 14%

 Other 9 34

Texas Excellent 480 1% 174 <1%

 Good 13,546 15% 16,324 18%

 Fair 53,543 57% 49,899 55%

 Poor 25,681 27% 24,922 27%

 Other 2,103 2,926

Total Excellent 1,412 1% 1,942 2%

 Good 17,420 16% 20,987 19%

 Fair 63,013 56% 56,930 52%

 Poor 30,225 27% 28,876 27%

 Other 2,147 3,038

NA = Data not available.

1 “Other” indicates land for which range condition guides are not available.

Technology 1996). The two predominant opposing viewpoints are epitomized by Fleischner (1994) and Box (1990). 

Fleischner believes grazing has caused a loss of biodiversity, disruption of ecosystem function, and irreversible changes in ecosystem structure, while Box concludes that the trend of U.S. public rangelands, on the 

average, has been upwards over a number of decades 

and the land is in the best ecological condition of this 

century.

The following report on condition of public rangelands 

can neither judge nor mediate the disparity in perspectives about their perceived status. It simply conveys information provided by the responsible agencies, in this case 

the BLM and Forest Service.

Lands Managed by the Bureau of Land 

Management

Until the mid-1970’s, the BLM used various qualitative methods for assessing range condition (Wagner 

1989). In 1977, the agency adopted a range site concept 

for its inventory procedure, called Soil-Vegetation Inventory Method (SVIM) (USDI Bureau of Land Management 

1979). Five years later, the BLM changed to the Ecological 

Site Inventory (ESI) Procedure used by the Soil Conservation Service (USDA Soil Conservation Service 1976, USDI 

Bureau of Land Management 1984). 

Since implementing SVIM and, later, ESI, the BLM has 

been inventorying its rangelands and classifying condition into four ecological status categories: Potential natural community (PNC, Küchler 1964), late seral, mid-seral, 

and early seral. These categories correspond to 76–100, 

51–75, 26–50, and 0–25 percent similarity, respectively, 

of the PNC species structure on a biomass basis (USDI 

Bureau of Land Management 1985). To date, the BLM has 

inventoried 85.7 million acres under SVIM/ESI, or about 

one-half of its rangelands (USDI Bureau of Land Management 1997a).

In the decade since the 1989 range assessment (Joyce 

1989), rangeland condition on BLM lands has not measurably changed in either the RM or the PC Assessment 

Region (table 3.7 and table 3.8). The results are consistent, even though the inventory methods have changed, 

as explained above. The BLM has no rangelands in the 

two eastern assessment regions. 

Rocky Mountain Assessment Region

Except for the southwestern states of Arizona and 

New Mexico, rangeland condition in the RM Assessment 

Region was fairly constant between 1986 and 1996 (USDI 

Bureau of Land Management 1987, 1997a). Arizona and, 

to a lesser extent, New Mexico both showed a greater 

increase in the areal extent of late seral communities and 

a decrease in the area of early seral communities (table 

3.7).

Pacifi c Coast Assessment Region

An initial scan of table 3.8 seems to indicate a dramatic 

decline in rangeland health in California since 1986. However, the 1986 statistics (USDI Bureau of Land Management 1987) included lands inventoried by fi ve techniques: 

ESI, professional judgment, seeding, annual range, and 

other. If the non-ESI acres, which were deleted by the 

later report (USDI Bureau of Land Management 1997a), 

are added to the 1996 acres that were inventoried under 

ESI, the results show little percentage change from 1986 

(unpublished data):

CA BLM Late Mid- Early

Lands PNC seral seral seral Unclass

1986 1% 44% 43% 10% 2%

1996 3% 40% 37% 15% 5%
32 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

 Year

State Condition Class 1986 1996

Arizona PNC2

 467 4% 521 9%

 Late seral 2,801 24% 2,217 40%

 Mid seral 6,068 52% 2,217 40%

 Early seral 2,334 20% 652 12%

 Unclassifi ed 0 913

 Not Inventoried 5,123

Colorado PNC 237 3% 140 5%

 Late seral 1,266 18% 630 22%

 Mid seral 3,403 48% 1,260 45%

 Early seral 2,216 31% 770 28%

 Unclassifi ed 791 700

 Not Inventoried 3,792

Idaho PNC 417 4% 182 2%

 Late seral 3,193 29% 2,002 24%

 Mid seral 4,304 39% 2,912 36%

 Early seral 3,054 28% 3,093 38%

 Unclassifi ed 2,916 910

 Not Inventoried 2,134

Montana PNC 397 6% 481 7%

 Late seral 4,764 67% 4,329 68%

 Mid seral 1,826 26% 1,512 24%

 Early seral 79 1% 69 1%

 Unclassifi ed 873 550

 Not Inventoried 1,027

Nevada PNC 2,771 6% 372 2%

 Late seral 12,010 27% 5,016 32%

 Mid seral 19,400 43% 8,360 52%

Table 3.7—Range condition on Bureau of Land Management rangelands1, 1986 and 1996: Rocky Mountain Assessment Region 

(acres 103

 and percent of total). Note: The acres and percentages by condition class shown for 1996 are based upon only those acres 

inventoried using the Soil-Vegetation Inventory Method or the Ecological Site Inventory (see text) and classifi ed by condition.

 Year

State Condition Class 1986 1996

Nevada, Early seral 10,624 24% 2,229 14%

 cont. Unclassifi ed 1,385 2,787

 Not Inventoried 29,056

New Mexico PNC 125 1% 102 1%

 Late seral 3,002 25% 3,555 36%

 Mid seral 6,003 50% 4,673 48%

 Early seral 2,877 24% 1,422 15%

 Unclassifi ed 500 305

 Not Inventoried 2,540

Utah PNC 893 5% 1,399 11%

 Late seral 6,476 35% 3,690 30%

 Mid seral 8,486 45% 5,471 45%

 Early seral 2,903 15% 1,654 14%

 Unclassifi ed 3,573 509

 Not Inventoried 8,482

Wyoming PNC 911 5% 438 7%

 Late seral 8,203 48% 3,137 48%

 Mid seral 6,745 40% 2,481 38%

 Early seral 1,094 7% 438 7%

 Unclassifi ed 1,276 803

 Not Inventoried 7,904

Total PNC 6,218 4% 3,635 5%

 Late seral 41,715 32% 24,576 37%

 Mid seral 56,235 50% 28,886 43%

 Early seral 25,181 14% 10,327 15%

 Unclassifi ed 800 7,477

 Not Inventoried 60,058

1

 Lands with grazing permits in grazing districts and lands with grazing leases (Section 15 lands).

2

 Potential Natural Community (see Küchler 1964; Glossary Update Task Group, Society for Range Management 1998). 

California is an unusual state because much of its rangeland is comprised of annual grassland, for which ESI classifi cation guides do not exist.

All BLM Lands

Condition of all lands managed by the BLM, taken 

together, was steady during the 10-year period, 1986 to 

1996 (USDI Bureau of Land Management 1987, 1997a):

All BLM Late Mid- Early

Lands PNC seral seral seral Unclass

1986 4% 31% 41% 17% 7%

1996 4% 33% 40% 14% 9%

Of the land for which actual range condition determinations were made using ESI/SVIM, about 42 percent was 

in PNC or a late seral stage, 44 percent was at an intermediate successional state, and 14 percent was dominated 

by early seral vegetation (USDI Bureau of Land Management 1997b).

Lands Managed by the Forest Service

In the last range assessment, Joyce (1989) reported 

upon the condition of rangelands managed by USDA 

Forest Service by Assessment Region in three different 

ways: (1) ecological status, using the same four categories as the BLM; (2) livestock forage value within ecological status; and (3) trend in ecological status. These 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 33

Rangeland Health CHAPTER 3

Table 3.8—Range condition on Bureau of Land Management 

rangelands1

, 1986 and 1996: Pacifi c Coast Assessment Region 

(acres 103

 and percent of total). Note: The acres and percentages by condition class shown for 1996 are based upon 

only those acres inventoried using the Soil-Vegetation Inventory 

Method or the Ecological Site Inventory (see text) and classifi ed 

by condition.

 Year

State Condition Class 1986 1996

California PNC2

 95 1% 41 3%

 Late seral3

 4,201 45% 273 21%

 Mid seral 4,106 44% 574 44%

 Early seral 955 10% 410 32%

 Unclassifi ed 191 55

 Not Inventoried 5,123

Oregon PNC 505 4% 88 1%

 Late seral 3,280 27% 2,900 35%

 Mid seral 6,308 52% 4,218 50%

 Early seral 2,145 17% 1,142 14%

 Unclassifi ed 379 351

 Not Inventoried 4,328

CA and OR PNC 600 3% 129 1%

 Late seral 7,481 35% 3,173 33%

 Mid seral 10,414 48% 4,792 50%

 Early seral 3,100 14% 1,552 16%

 Unclassifi ed 570 406

 Not Inventoried 9,451

1

 Lands with grazing permits in grazing districts and lands with grazing 

leases (Section 15 lands).

2

 Potential Natural Community (see Küchler 1964; Glossary Update Task 

Group, Society for Range Management 1998).

3

 For explanation of apparent decline of rangeland classifi ed as late seral 

between 1986 and 1996, see text.

estimates were derived from unpublished contents analyses of forest plans (fi gure 3.1). The same approach was 

not repeated for the present assessment because very few 

forest plans have been revised.

The Forest Service presently does not publish summaries of range condition, per se. Alternatively, the agency 

identifi es areas of rangeland vegetation that meet, are 

progressing towards, or neither meet nor are progressing 

towards established Forest Plan Management Objectives 

(FPMO). Land is classifi ed only in conformity with rangeland-related attributes of each forest plan. The three categories are comprised of lands that are monitored (thus, 

verifi ed as being in that category) and unmonitored (estimated to be in that category). Upland and riparian lands 

are reported separately.

There is at least one diffi culty associated with categorizing rangeland health in terms of FPMO’s: most 

National Forests are still operating under the fi rst round 

of forest plans approved in the 1980’s, and the elements 

relating to rangeland health are not well correlated to 

trends in indicators judged to be relevant by contemporary standards (Committee on Rangeland Classifi cation 

1994). For example, numerous forest plans employ utilization standards as criteria to limit livestock grazing use 

to that believed necessary to maintain or improve targeted rangelands (USDA Forest Service 1985). Yet, some 

observers consider this approach, in a de facto manner, 

also is unduly being used to monitor changes needed 

to determine if overall FPMO’s are being met (Sanders 

1998). 

Even though the Forest Service expressed range condition by an indirect ordinal measure (proportion of land in 

relation to FPMO’s), the results probably portray conditions at a national scale with reasonable accuracy. Hierarchy theory postulates that ecosystem processes and characteristics, including those relating to sustainability, differ 

according to the temporal and spatial scale on which they 

are organized (Allen and Starr 1982, O’Neill 1989). Slowchanging, generalized features have been incorporated 

into indicators of forest health at a national level as part 

of the Montreal Process (Coulombe 1995). The Forest Service fi ndings on range condition fi t this classifi cation.

Pacifi c Coast Assessment Region

The PC Assessment Region includes the Pacifi c Southwest (R-5) and Pacifi c Northwest Regions (R-6) of the 

Forest Service. As of 1998, all Forests in R-5 were still 

operating under their original plans, although several 

plans were completed after 1992 and two Forests had 

completed range-related amendments to their plans. The 

Forests in R-6 were in the same situation in 1998, except 

that the 17 National Forests west of the summit of the Cascade Mountains fell under the authority of the Northwest 

Forest Plan covering the protection of spotted owl and 

anadromous fi sh habitats (USDA Forest Service, Pacifi c 

Northwest Region 1998). East of the Cascade Mountains 

summit, Forest plans were subject to restrictions for managing riparian zones and contiguous uplands for anadromous and native fi sh species by two interim strategies, 

PACFISH and INFISH (Pacifi c States Marine Fisheries 

Commission 1995).

The area of upland rangeland vegetation within grazing allotments falling in the three categories relating to 

FPMO’s is depicted by Forest Service Region (table 3.9 and 

table 3.10). For the entire PC Assessment Region, approximately 95 percent of rangeland within grazing allotments 

is either meeting or progressing towards FPMO’s (table 

3.11). The only difference between R-5 and R-6 is the fraction of land that already meets FPMO’s, two-thirds and 

one-half, respectively. 

The 5 percent of lands not meeting nor progressing 

towards FPMO’s is less than the 15 percent of lands esti-
34 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

Table 3.9—Area of upland range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): Pacifi c Southwest Region — CA (acres 103

).

Year

Land Category 1995 1996 1997

Total range vegetation 7,055 6,775 7,121

Having range vegetation management objectives 7,055 6,760 7,106

Monitored during current year 1,806 1,784 1,626

Verifi ed meeting FPMO 809 855 841

Estimated meeting FPMO 1,682 1,641 1,650

Total 2,491 (67%) 2,496 (67%) 2,491 (68%)

Verifi ed moving toward FPMO 250 261 243

Estimated moving toward FPMO 786 788 737

Total 1,036 (28%) 1,049 (28%) 980 (27%)

Verifi ed not meeting or moving toward FPMO 28 27 28

Estimated not meeting or moving toward FPMO 178 178 139

Total 206 (5%) 205 (5%) 167 (5%)

Undetermined status 3,322 3,025 3,483

Figure 3.1—Well-managed fescue grassland on the Pike National Forest, Colorado. This allotment is in a desired ecological 

state and has high forage value, as called for in the Forest Plan.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 35

Rangeland Health CHAPTER 3

Table 3.10—Area of upland range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): Pacifi c Northwest Region — OR, WA (acres 103

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 10,383 10,252 10,243

Monitored during current year 3,249 3,262 2,822

Verifi ed meeting FPMO 742 710 665

Estimated meeting FPMO 2,840 2,812 2,872

Total 3,582 (49%) 3,522 (50%) 3,537 (51%)

Verifi ed moving toward FPMO 432 368 201

Estimated moving toward FPMO 2,870 2,930 2,978

Total 3,302 (45%) 3,298 (46%) 3,179 (45%)

Verifi ed not meeting or moving toward FPMO 84 62 58

Estimated not meeting or moving toward FPMO 353 231 232

Total 437 (6%) 293 (4%) 290 (4%)

Undetermined status 3,075 3,139 3,237

Table 3.11—Area of upland range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): Pacifi c Coast Assessment Region (acres 103

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 17,438 17,012 17,349

Monitored during current year 5,055 5,046 4,448

Verifi ed meeting FPMO 1,551 1,565 1,506

Estimated meeting FPMO 4,522 4,453 4,522

Total 6,073 (55%) 6,018 (55%) 6,028 (57%)

Verifi ed moving toward FPMO 682 629 444

Estimated moving toward FPMO 3,656 3,718 3,715

Total 4,338 (39%) 4,347 (40%) 4,159 (39%)

Verifi ed not meeting or moving toward FPMO 112 89 86

Estimated not meeting or moving toward FPMO 531 409 371

Total 643 (6%) 498 (5%) 457 (4%)

Undetermined status 6,384 6,149 6,705

mated to be in early-seral stage or moving away from 

PNC in 1986 (Joyce 1989). Since the two approaches 

are not comparable, however, no conclusions concerning 

trend in condition can be drawn.

Rocky Mountain Assessment Region

The RM Assessment Region includes four Forest Service Regions: Northern (R-1), Rocky Mountain (R-2), 

Southwest (R-3), and Intermountain (R-4) (fi gure 1.5). As 

of 1998, all Forests in R-1 were operating on fi rst-round 

plans with no signifi cant rangeland-related amendments. 

In R-2, 4 out of 10 Forests had new forest plans. In R-3, 

all Forests were still operating on their original plans, 

although the forest plans were amended in 1996 to add 

updated grazing utilization standards. In R-4, all Forests 

but three were operating on their original plans; one had 

a revised plan and two had range-related amendments. 

The area of upland rangeland vegetation within grazing allotments falling in the three categories relating to 

FPMO’s is depicted by Forest Service Region (table 3.12 

through table 3.15). By the standards described herein, 
36 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

Table 3.12—Area of upland range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): Northern Region — MT, northern ID, ND, northwest SD (acres 103

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 5,219 4,660 4,664

Monitored during current year 1,376 1,288 1,300

Verifi ed meeting FPMO 157 160 192

Estimated meeting FPMO 3,197 2,841 2,832

Total 3,354 (64%) 3,001 (64%) 3,024 (65%)

Verifi ed moving toward FPMO 45 45 48

Estimated moving toward FPMO 882 822 820

Total 927 (18%) 867 (19%) 868 (19%)

Verifi ed not meeting or moving toward FPMO 6 5 9

Estimated not meeting or moving toward FPMO 933 788 763

Total 939 (18%) 793 (17%) 772 (16%)

Undetermined status 0 0 0

Note: The total area having range management objectives for 1995 exceeds that for 1996 and 1997 because of a reporting error. The 1995 estimates 

assume the land mistakenly included was distributed in the same manner as the land appropriately included.

Table 3.13—Area of upland range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): Rocky Mountain Region — CO, KS, NE, SD, eastern WY (acres 103

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 11,924 11,435 11,533

Monitored during current year 2,621 2,574 2,830

Verifi ed meeting FPMO 2,358 2,483 2,781

Estimated meeting FPMO 3,509 3,306 3,262

Total 5,867 (61%) 5,789 (64%) 6,043 (65%)

Verifi ed moving toward FPMO 533 600 583

Estimated moving toward FPMO 2,496 2,091 2,066

Total 3,029 (32%) 2,691 (29%) 2,649 (29%)

Verifi ed not meeting or moving toward FPMO 124 200 141

Estimated not meeting or moving toward FPMO 544 446 414

Total 668 (7%) 646 (7%) 555 (6%)

Undetermined status 2,360 2,309 2,286

the RM Assessment Region is clearly in less desirable condition than the PC and NO Assessment Regions: 15 percent of rangeland within grazing allotments is neither 

meeting nor moving towards FPMO’s (table 3.16). This 

proportion conforms to the estimate of National Forest 

System (NFS) lands in early seral successional stages or 

progressing away from PNC in 1986 (Joyce 1989).

Vegetation in the mostly dry Southwestern Region 

has been subjected to a history of fi re suppression since 

the late 19th Century and improper grazing, primarily 

between the 1880’s and World War I (Secretary of Agriculture 1936, Rasmussen 1941, Cooper 1960, Buffi ngton and 

Herbel 1965, Mortensen 1978). These factors and others 

have caused upland vegetation and soil changes that are 

slow to improve, some of which probably will not ever 

recover to pre-existing conditions (Schlesinger et al. 1990, 

Wang and Hacker 1997). As a result, the higher percentage of rangeland in R-3 that is not meeting or progress-
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 37

Rangeland Health CHAPTER 3

Table 3.14—Area of upland range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): Southwestern Region — AZ, NM (acres 103

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 18,320 18,332 18,019

Monitored during current year 4,859 6,348 6,364

Verifi ed meeting FPMO 1,676 1,859 1,945

Estimated meeting FPMO 2,541 2,595 2,376

Total 4,217 (26%) 4,454 (27%) 4,321 (27%)

Verifi ed moving toward FPMO 1,486 1,456 1,455

Estimated moving toward FPMO 6,227 6,208 6,105

Total 7,713 (47%) 7,664 (46%) 7,560 (47%)

Verifi ed not meeting or moving toward FPMO 788 673 741

Estimated not meeting or moving toward FPMO 3,663 3,702 3,548

Total 4,451 (27%) 4,375 (27%) 4,289 (26%)

Undetermined status 1,938 1,839 1,849

Table 3.15—Area of upland range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): Intermountain Region — Southern ID, NV, UT, western WY (acres 103

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 23,192 19,172 19,547

Monitored during current year 7,805 6,076 5,224

Verifi ed meeting FPMO 2,068 2,090 2,321

Estimated meeting FPMO 6,483 5,548 5,771

Total 8,551 (46%) 7,638 (48%) 8,092 (49%)

Verifi ed moving toward FPMO 1,136 1,073 870

Estimated moving toward FPMO 7,511 5,899 6,361

Total 8,647 (47%) 6,972 (44%) 7,231 (43%)

Verifi ed not meeting or moving toward FPMO 87 64 70

Estimated not meeting or moving toward FPMO 1,305 1,304 1,284

Total 1,392 (7%) 1,368 (8%) 1,354 (8%)

Undetermined status 4,602 3,194 2,870

Note: The total area of range vegetation for 1995 exceeds that for 1996 and 1997 because of a reporting error. The 1995 estimates assume the land 

mistakenly included was distributed in the same manner as the land appropriately included.

ing towards FPMO’s, roughly 25 percent, should not be 

surprising (table 3.14). 

South Assessment Region

The SO Assessment Region includes only one Forest 

Service Region, the Southern (R-8). Fourteen Forests are 

operating on fi rst-round plans, two of which have signifi cant revisions, and four Forests have revised forest 

plans.

Table 3.17 suggests an apparent trend of decreasing land 

moving towards FPMO’s and increasing land that neither 

meets nor moves towards FPMO’s for NFS rangelands in 

R-8. However, unpublished information (personal communication, Mr. Levester Pendergrass, R-8, Atlanta, GA) 

indicates the 1997 data in the table represent stable conditions that have actually changed little over the past decade. 

The 16 percent of NFS rangelands in grazing allotments 

that are not meeting nor progressing towards FPMO’s puts 

it on a par with the RM Assessment Region.
38 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

Table 3.16—Area of upland range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): Rocky Mountains Assessment Region (acres 103

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 58,655 53,599 53,763

Monitored during current year 16,661 16,286 15,718

Verifi ed meeting FPMO 6,259 6,592 7,239

Estimated meeting FPMO 15,730 14,290 14,241

Total 21,989 (44%) 20,882 (45%) 21,480 (46%)

Verifi ed moving toward FPMO 3,200 3,174 2,956

Estimated moving toward FPMO 17,116 15,020 15,352

Total 20,316 (41%) 18,194 (39%) 18,308 (39%)

Verifi ed not meeting or moving toward FPMO 1,005 942 961

Estimated not meeting or moving toward FPMO 6,445 6,240 6,009

Total 7,450 (15%) 7,182 (16%) 6,970 (15%)

Undetermined status 8,900 7,341 7,005

Table 3.17—Area of upland range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): South Assessment Region (acres 103

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 1,523 1,262 1,169

Monitored during current year 238 269 250

Verifi ed meeting FPMO 405 421 370

Estimated meeting FPMO 546 500 473

Total 951 (76%) 921 (82%) 843 (76%)

Verifi ed moving toward FPMO 1 16 51

Estimated moving toward FPMO 286 147 32

Total 287 (23%) 163 (14%) 83 (8%)

Verifi ed not meeting or moving toward FPMO 0 7 7

Estimated not meeting or moving toward FPMO 21 39 170

Total 21 (1%) 46 (4%) 177 (16%)

Undetermined status 264 132 66

North Assessment Region

The NO Assessment Region also includes only one 

Forest Service Region, the Eastern (R-9). The Eastern 

Region has 15 Forests operating under their original 

plans, and none has a signifi cant revision related to rangelands. Rangelands in R-9 are in exemplary condition in 

relation to FPMO’s (table 3.18). Less than 5 percent of 

range vegetation within grazing allotments is not meeting 

nor progressing towards management goals. The large 

disparity between areas meeting FPMO’s versus areas 

moving toward FPMO’s represents, like that described 

above for the SO Assessment Region, a correction resulting from more complete verifi cation and improved estimates of the actual status of land in grazing allotments 

(personal communication with Ken Holtje, R-9, Milwaukee, WI).

All NFS Lands

Even though the current protocol for appraising range 

condition is fundamentally different from that used for the 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 39

Rangeland Health CHAPTER 3

Table 3.18—Area of upland range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): North Assessment Region (acres 103

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 66 66 65

Monitored during current year 63 63 48

Verifi ed meeting FPMO 26 27 12

Estimated meeting FPMO 4 4 8

Total 30 (49%) 31 (49%) 20 (33%)

Verifi ed moving toward FPMO 24 24 9

Estimated moving toward FPMO 6 6 32

Total 30 (48%) 30 (48%) 41 (67%)

Verifi ed not meeting or moving toward FPMO 0 0 0

Estimated not meeting or moving toward FPMO 2 2 0

Total 2 (3%) 2 (3%) 0 (0%)

Undetermined status 4 3 4

last Assessment, two factors allow one to accept the null 

hypothesis that rangeland health of uplands on NFS lands 

is fairly static: (1) the lack of any short-term trend between 

1995 and 1997, and (2) the congruity of results presented 

above with Joyce’s (1989) general conclusions showing only 

about one acre in seven on NFS lands in a less than satisfactory ecological condition or downward trend.

Rangeland health has clearly improved over the past 

20 years, regardless of its present stable state, if conditions now are compared to those presented in the 1979 

RPA Assessment document (USDA Forest Service 1980). 

Although it did not separate NFS lands, the 1979 Assessment estimated that at least half of all rangelands were in 

poor or very poor condition. And, in the Rocky Mountain 

states where most NFS rangelands are situated, the percentage of rangelands in poor or very poor condition was 

nearly identical to the Nation as a whole.

Another consideration concerns the proportion of NFS 

land within grazing allotments that have an undetermined status, nearly 20 percent of the total. The percentages shown in parentheses in table 3.9 through table 3.19 

are based upon only those lands that have been cateTable 3.19—Area of upland range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): All NFS lands (acres 103

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 77,682 71,939 72,346

Monitored during current year 22,017 21,664 20,464

Verifi ed meeting FPMO 8,241 8,578 9,127

Estimated meeting FPMO 20,802 19,247 19,247

Total 29,043 (47%) 27,825 (48%) 28,374 (49%)

Verifi ed moving toward FPMO 3,907 3,843 3,460

Estimated moving toward FPMO 21,064 18,891 19,131

Total 24,971 (40%) 22,734 (39%) 22,591 (38%)

Verifi ed not meeting or moving toward FPMO 1,117 1,038 1,054

Estimated not meeting or moving toward FPMO 6,999 6,690 6,550

Total 8,116 (13%) 7,728 (13%) 7,604 (13%)

Undetermined status 15,552 13,625 13,780
40 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

gorized; thus, they sum to 100 percent in each column. 

These percentages assume that allotments yet to be categorized will follow the same distribution as those which 

have been categorized. Such an assumption obviously 

may not be true.

The low level of funding for rangeland vegetation 

management and grazing management programs on NFS 

lands may be contributing to the static nature of range 

condition in recent years. According to unpublished information provided by the Forest Service Washington Offi ce 

Range Staff, the regional distribution of appropriated 

rangeland vegetation and grazing management funds 

remained fairly stagnant throughout the 1990’s at a level 

only adequate to pay administrative costs for managing 

most NFS grazing programs. In the Pacifi c Northwest 

Region, where about one-half of allotments are subject 

to the terms and conditions contained in biological opinions, the current budget does not meet administrative 

costs (Personal communication with Richard Lindenmuth, Pacifi c Northwest Region, USDA Forest Service, 

Portland, OR). Therefore, the only funds used by the 

Regions for actual rangeland improvements were range 

betterment funds returned from grazing fees. Because of 

declining grazing fees (based upon P.L. 95-514, Public 

Rangelands Improvement Act of 1978), total range betterment funding declined from $5.3 million in 1993 to $3.1 

million in 1998.

Riparian Areas

In March 1996, the Chief of the Forest Service and 

the Director of the BLM, in cooperation with NRCS, initiated an interagency strategy for “accelerating cooperative riparian restoration and management” starting in the 

11 western states. This approach is based on the premise 

that restoration and management must be addressed on 

a watershed scale in cooperation with all landowners 

in order to be successful. The emphasis is also on problem resolution at the ground level by the people most 

affected by success or failure. The interagency commitment included formation of a National Riparian Service 

Team (NRST), headquartered in Prineville, OR, to promote and lead this collaborative effort.

The Proper Functioning Condition (PFC) assessment 

was selected as the foundation tool to help people of 

diverse backgrounds focus initially on the physical function of riparian-wetland areas rather than values produced, such as habitat, forage, etc. This provides an effective fi rst step toward development of cooperative management plans, and also helps guide restoration and monitoring priorities. The PFC assessment is intended to be 

performed by a journey level, interdisciplinary team that 

includes specialists in vegetation, soils, and hydrology 

(Barrett et al. 1995, Bridges et al. 1994). This method relies 

on a qualitative checklist, supported by quantitative sampling techniques where answers are uncertain or where 

experience is limited. 

The on-the-ground condition termed PFC refers to 

how well the physical processes are functioning. The PFC 

assessment is designed to determine four defi ned states: 

proper functioning condition, functional-at risk, nonfunctional, and unknown. PFC is a state of resiliency that will 

allow a riparian-wetland area to hold together during 

moderately high fl ow events, sustaining that system’s 

ability to produce values related to both physical and biological attributes. PFC does not automatically indicate a 

desired (future) condition, but is always a prerequisite to 

achieving desired condition. 

Both the BLM and Forest Service have been collecting 

data on the status of riparian areas for a number of years. 

Beginning with their Riparian-Wetland Initiative for the 

1990’s (USDI Bureau of Land Management 1991), BLM 

began assessing and reporting riparian condition in terms 

of PFC status. The Forest Service, through direction outlined in “Riparian Management — A Leadership Challenge” (Robertson 1992), uses the same reporting method 

it employs for uplands. For rangelands, that includes 

the number of acres within grazing allotments meeting, 

moving towards, or neither meeting nor moving towards 

forest plan objectives.

BLM Lands

The status of riparian areas on BLM lands in 1997 is 

reported by state and assessment region in table 3.20. For 

all BLM lands in the conterminous United States, 12,014 

miles (41 percent) are at PFC, 12,888 miles (45 percent) 

are functional but at risk, and 3,965 miles (14 percent) are 

non-functional. One-fourth (9,854 miles) of BLM streams 

have not been inventoried for condition, so their status is 

unknown (USDI Bureau of Land Management 1997a). In 

1995, 11,352 miles had not been inventoried in the same 

western states (USDI Bureau of Land Management 1995). 

The Agency has an ambitious plan to inventory and classify its riparian areas and wetlands, so succeeding Assessments should contain more complete information (USDI 

Bureau of Land Management 1991). All surveys are to 

be completed during fi scal year 2000, and a sample of 

functional-at risk systems where management changes 

have been made will be re-analyzed for the purpose of 

determining resultant trends (Personal communication, 

NRST).

NFS Lands

The status of riparian condition varies among assessment regions. In the PC Assessment Region, about 10 percent of the area of riparian rangeland vegetation within 

grazing allotments is neither meeting nor moving towards 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 41

Rangeland Health CHAPTER 3

Table 3.20—Status of riparian areas on BLM lands in 1997 that have been classifi ed using Proper Functioning Condition (PFC) 

(Barrett et al. 1995).

PFC Condition Class

 PFC Functioning-at risk Non-functional

State/Assessment Region Miles Percent Miles Percent Miles Percent

California 1,750 61 1,023 36 87 3

Oregon/Washington 1,575 49 1,469 45 197 6

Pacifi c Coast Assessment Region 3,325 54 2,492 41 284 5

Arizona 290 39 436 58 21 3

Colorado 1,942 48 1,415 35 700 17

Idaho 932 41 966 43 352 16

Montana 2,048 43 2,225 46 523 11

Nevada 361 26 543 38 513 36

New Mexico 137 33 184 45 88 22

Utah 1,657 46 1,447 40 502 14

Wyoming 1,322 24 3,180 58 982 18

Rocky Mountains Assessment Region 8,689 38 10,396 46 3,681 16

Source: USDI Bureau of Land Management (1998)

FPMO (table 3.21). As mentioned above, it should be 

noted that three working strategies for protecting and 

restoring anadromous and native fi sh habitats, the Northwest Forest Plan, PACFISH, and INFISH, have effectively 

modifi ed Forest plans throughout the Pacifi c Northwest 

Region.

In the RM Assessment Region, about one riparian acre 

in six does not meet nor is progressing towards FPMO 

(table 3.22). Interestingly, this is the same proportion as 

Table 3.21—Area of riparian range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): Pacifi c Coast Assessment Region (acres 102

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 7,983 7,922 7,854

Monitored during current year 2,317 2,241 1,940

Verifi ed meeting FPMO 867 948 796

Estimated meeting FPMO 1,886 1,823 1,528

Total 2,753 (50%) 2,771 (51%) 2,324 (45%)

Verifi ed moving toward FPMO 594 450 407

Estimated moving toward FPMO 1,408 1,754 1,939

Total 2,002 (36%) 2,204 (40%) 2,346 (46%)

Verifi ed not meeting or moving toward FPMO 176 120 126

Estimated not meeting or moving toward FPMO 598 342 343

Total 774 (14%) 462 (9%) 469 (9%)

Undetermined status 2,454 2,485 2,715

was reported as being nonfunctional by the BLM for their 

riparian lands in the RM Assessment Region (table 3.20). 

Both the SO and NO Assessment Regions contain very 

little riparian range vegetation, and nearly all of these 

lands already meet FPMO (table 3.23 and table 3.24).

There are several reasons why the condition of riparian areas in arid and semi-arid regions can improve more 

quickly than associated uplands. Because of vegetation 

and physical characteristics refl ective of permanent sur-
42 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

Table 3.22—Area of riparian range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): Rocky Mountains Assessment Region (acres 102

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 16,340 15,317 15,760

Monitored during current year 4,935 4,169 4,400

Verifi ed meeting FPMO 1,391 1,450 1,777

Estimated meeting FPMO 4,549 4,421 4,662

Total 5,940 (42%) 5,871 (45%) 6,439 (47%)

Verifi ed moving toward FPMO 922 858 875

Estimated moving toward FPMO 4,519 3,973 4,092

Total 5,441 (39%) 4,831 (37%) 4,967 (37%)

Verifi ed not meeting or moving toward FPMO 402 266 208

Estimated not meeting or moving toward FPMO 2,226 2,059 1,905

Total 2,628 (19%) 2,325 (18%) 2,113 (16%)

Undetermined status 2,331 2,290 2,241

Table 3.23—Area of riparian range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): South Assessment Region (acres 102

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 654 609 597

Monitored during current year 38 33 28

Verifi ed meeting FPMO 68 67 65

Estimated meeting FPMO 241 206 199

Total 309 (82%) 273 (79%) 264 (79%)

Verifi ed moving toward FPMO 10 6 6

Estimated moving toward FPMO 58 42 39

Total 68 (18%) 48 (14%) 45 (14%)

Verifi ed not meeting or moving toward FPMO 1 0 0

Estimated not meeting or moving toward FPMO 0 23 23

Total 1 (0%) 23 (7%) 23 (7%)

Undetermined status 276 265 265

face or sub-surface water, these areas often exhibit faster 

recovery rates from the effects of improper management 

(Alford 1993, Hindley 1996, Mosley et al. 1997). Additionally, the strategic goals of the Forest Service, NRCS, and 

the BLM include specifi c objectives designed to restore 

and maintain watershed function and structure in order 

to reduce erosion and improve water quality. The overall 

goals of the Clean Water Act are further supported by the 

interagency responsibilities outlined in the Clean Water 

Action Plan (CWAP), announced by the President on February 19, 1998. The CWAP contains key action items for 

federal agencies and provides for incentives relative to 

private land stewardship.

Some reviewers conclude that grazing by domestic 

livestock is not compatible with restoring watersheds and 

water quality, at least in the short term (Belsky et al. 

1999). However, comparitive research and case studies 

show that improved rangeland and livestock management practices are compatible with watershed and water 

quality improvement when designed to address the attri-
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 43

Rangeland Health CHAPTER 3

Table 3.24—Area of riparian range vegetation within grazing allotments on National Forest System lands in relation to Forest Plan 

Management Objectives (FPMO): North Assessment Region (acres 102

).

Year

Land Category 1995 1996 1997

Having range vegetation management objectives 17 17 1

Monitored during current year 12 12 1

Verifi ed meeting FPMO 2 2 1

Estimated meeting FPMO 2 2 0

Total 4 (29%) 4 (29%) 1 (100%)

Verifi ed moving toward FPMO 1 1 0

Estimated moving toward FPMO 6 6 0

Total 7 (50%) 7 (50%) 0 (0%)

Verifi ed not meeting or moving toward FPMO 1 1 0

Estimated not meeting or moving toward FPMO 2 2 0

Total 3 (21%) 3 (21%) 0 (0%)

Undetermined status 3 3 0

butes of each individual site (Elmore and Kauffman 1994). 

Ultimately, social and political values, along with scientifi c knowledge, will drive future laws and regulations 

affecting the grazing use of riparian areas, just as they 

will for uplands (Lee 1993).

Lands Managed by Department of Defense

The Department of Defense (DOD) is responsible for 

administering more than 25 million acres of federal land 

in the United States (Public Land Law Review Commission 1970). In addition to these lands, DOD services 

have agreements with states and other federal land managment agencies, including the Forest Service, to allow 

training use on 15 million additional acres (Council on 

Environmental Quality 1989). The U.S. Army Corps of 

Engineers manages 12 million acres of this land through 

its civil works programs. 

Military commanders responsible for DOD lands must 

address two important national goals: maintaining military readiness and safeguarding the environment. The 

emphasis on environmental stewardship began with a 

1989 challenge by Secretary Cheney for DOD to be “the 

federal leader in environmental compliance and protection” (Baca 1992). On the other hand, military readiness increasingly requires large-unit, mechanized exercises that reduce vegetation cover and soil stability, and 

destroy woody vegetation (Siehl 1991). Consequently, the 

military has become more and more involved in land 

management and land restoration concurrently with the 

execution of its training activities (Berlinger and Cammack 1990). Conservation has been incorporated into 

training guidelines at all installations (Shaw and Diersing 

1989). Protection of plant and animal species for biodiversity is receiving increased consideration in military land 

management planning (Vogel 1997).

In the mid-1980’s the U.S. Army initiated a servicewide ecosystem monitoring program called Land Condition-Trend Analysis (Diersing et al. 1992). The procedures 

adopted are described in a Corps of Engineers technical 

manual (Tazik et al. 1992). Although the base sampling 

protocols are the same worldwide, the amount of information synthesized across a regional or national scale is 

still limited. This situation is expected to improve greatly 

over the next few years through improved data analysis 

and synthesis activities, and collaboration with other land 

management agencies (Mitchell and Shaw 1993).

A recent report provides an approximation of ecosystem health for training lands in the continental United 

States administered by DOD (Shaw and Kowalski 1996). 

The authors surveyed 32 military installations, half of 

which were dominated by desert, grassland, shrubland, 

or woodland vegetation. The land area of the 16 installations characterized by rangeland ecosystems was 7.1 

million acres. About 20 percent of all rangeland showed 

evidence of livestock use. The principal disturbances on 

military lands were related to human activities, however. 

Approximately 17 percent of all lands, including forests, 

was disturbed because of military operations. Sixty percent of this land area showed signs of accelerated erosion. 

Evidence of fi res could be found on almost two-thirds 

of the land, often because of use of munitions and other 

incendiary devices (Shaw and Kowalski 1996).
44 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

Expansion of Woodlands

Trees and shrubs are found on rangelands worldwide. 

Nonetheless, native woody plants have rapidly increased 

in abundance on a number of arid and semi-arid grassland steppes and savannas over the past century, clearly 

expanding beyond their historical range of distribution 

in the United States (Archer 1994). The area of these 

expanded woodland types, as well as the increased soil 

erosion that can accompany such land cover shifts, are 

indicators of sustainability under the Montreal Process 

(USDA Forest Service 1997). 

Ecologists fi rst noticed the invasion of grasslands by 

woodland species early in the 20th Century (Foster 1917, 

Leopold 1924). By mid-century, numerous scientifi c articles addressed the issue of increasing extent and/or density of mesquite (Prosopis glandulosa) (Allred 1949, Brown 

1950), creosote bush (Larrea tridentata) (Gardner 1951), 

and juniper (Juniperus spp.) (Johnson 1962, Burkhardt and 

Tisdale 1969). Oak brush (Quercus gambelii) was noted to 

thicken, if not spread, under disturbance by fi re or cutting (Brown 1958). At that time, Platt (1959) estimated 

that these woody species occupied the following area:

Species Area (acres 106

)

Mesquite 93.0

Creosote bush 46.5

Juniper 63.9

Oak brush 40.2

The causes of woodland expansion, and the resultant 

balance between the distributions of grasslands and 

woody plant communities, are complex and interactive. 

They comprise changing climate, including episodic 

events, grazing, and fi re (Archer et al. 1999). Grover and 

Musick (1990) concluded that the extensive expansion of 

mesquite and creosote bush in the Southwest was brought 

about by livestock overgrazing in the late 19th Century 

that coincided with drought conditions unfavorable for 

perennial grass growth. Evidence is beginning to suggest 

that droughts and global warming may favor forbs and 

some woody species over grasses in parts of North America (Turner 1990, Paruelo and Lauenroth 1996, Alward et 

al. 1999).

Non-equilibrium successional models with a critical 

threshold between the grassland domain and woodland/

shrubland domain also provide a mechanism for explaining dynamic interactions between grasslands and woodlands (Archer and Smeins 1991). Increased grazing and 

decreased fi re frequency can drive succession towards 

a woodland state (fi gure 3.2). If grazing pressure is 

relaxed prior to reaching some critical threshold, succession towards a later seral grassland can occur; otherwise, 

the transition can be permanent (Archer 1989). 

Most research evidence indicates that two of the major 

anthropocentric disturbance factors, livestock grazing and 

fi re, had their controlling impacts in the late 19th and early 

20th centuries—the time shortly before woodland expansions were being documented (Buffi ngton and Herbel 

1965, Baisan and Swetnam 1997). An additional factor, nonindigenous plants, has continued to deleteriously affect 

woodlands by forming closed, mono-specifi c understories 

that decrease biodiversity (Young and Longland 1996) and 

promote accelerated erosion (West 1991b). 

A number of management techniques have been 

devised over the past half-century to reduce or eliminate 

tree dominance in woodlands. Fire has seldom worked 

in pinyon-juniper because of a lack of fi ne fuels, often 

caused by grazing, to carry a fi re (Miller et al. 1994). Treatments other than fi re, such as cabling and chaining, were 

fi rst designed to increase forage production for livestock 

and harvest fi rewood. The management emphasis for 

treating woodlands in recent years has been to enhance 

wildlife habitat. Wildlife treatments have generally been 

less frequent and tended to involve smaller areas than 

natural wildfi res, allowing trees to more rapidly reoccupy their former territories. Some treatments have 

included seeding of introduced grasses and forbs that 

replaced native species, detrimentally impacting biodiversity (Richards et al. 1998). 

Although most scientifi c literature supports the premise that controlling pinyon-juniper in areas outside its 

Low Low High

High Low

Low High

Woodland

succession

Transition threshold

Grazing intensity

Fire frequency

Probability and rate

of woody plant establishment

Woodland

Domain

Grassland

Domain

Woody

plants

Perennial

grasses

A

B

C

A Grassland PNC

Grassland

succession

Grassland

retrogression =

B Grassland seral state =

C Woodland seral state =

Community composition

Fig. 3.2—Conceptual model of how grazing and fi re interact 

to convert a grassland to a shrub-dominated ecosystem. The 

threshold is determined by the establishment of shrub-driven 

successional processes once shrub dominance reaches a critical level (adapted from Archer 1989).
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 45

Rangeland Health CHAPTER 3

recent historical range reduces erosion and increases soil 

water and understory abundance, this conclusion is not 

unanimous (Belsky 1996). 

Woody cover of mesquite, creosote bush, and juniper 

on non-federal rangelands in the PC, RM, and SO Assessment Regions is presented in table 3.25 (from unpublished 

1992 supplemental NRI study, described earlier in the 

section on non-federal rangeland health). Although the 

total acreages cannot be compared with Platt’s (1959) estimates, the 1992 data do provide an interesting perspective on cover class distributions for non-federal lands. 

In general, the areas dominated by woody species are 

characterized by communities with less than 20 percent 

canopy cover. It should be noted that non-federal lands 

Table 3.25—Area of non-federal rangelands for selected woody species, by cover class, for selected states, in 1992 (acres 103).

Total Woody Cover (%)

Region/Species <1 1–9 9–20 20–30 30–40 >40 Total

Pacifi c Coast Assessment Region

 California

 Pinyon-Juniper 0 65 254 241 0 81 641

 Creosote bush 0 66 261 265 265 643 1,500

 Oregon

 Juniper 295 636 651 314 147 89 2,312

Rocky Mountains Assessment Region

 Arizona

 Pinyon-Juniper 695 3,593 1,220 517 210 53 6,288

 Creosote bush 222 1,923 2,199 894 299 0 5,537

 Mesquite 0 104 57 57 57 229 514

 Colorado

 Pinyon-Juniper 187 760 376 0 31 31 1,385

 Idaho

 Juniper 0 0 87 14 0 0 101

 Nevada

 Pinyon-Juniper 26 270 237 18 18 0 569

 Creosote bush 0 103 137 0 0 0 240

 New Mexico

 Pinyon-Juniper 583 7,048 4,478 765 368 21 13,283

 Creosote bush 73 1,001 601 140 74 1 1,890

 Mesquite 941 4,213 2,258 756 140 81 8,389

 Utah

 Pinyon-Juniper 77 852 367 98 95 0 1,489

Southern Assessment Region

 Oklahoma

 Mesquite 68 477 151 0 0 0 696

 Texas

 Juniper 1,424 8,620 5,289 1,823 1,002 1,702 19,860

 Creosote bush 780 3,657 2,706 616 118 127 8,004

 Mesquite 4,067 20,032 14,349 4,782 2,054 2,143 47,430

occupy less than one-fourth of all lands in the two principal pinyon-juniper states of the Great Basin, Nevada 

and Utah (USDA Soil Conservation Service 1990). Further, private lands in the Great Basin are situated primarily at lower elevations and do not include many productive sites (West et al. 1978). Research has shown that 

woodlands have greater canopy cover at higher elevations in the Great Basin, and that the median cover for all 

sites is on the order of 45–50 percent (fi gure 3.3) (Tausch 

and Tueller 1990, West et al. 1998).

The increased distribution, density, and crown size of 

pinyon-juniper on more favorable sites typical of federal 

lands have amplifi ed the risk of large crown fi res that 

have the potential to burn over large areas. The area of 
46 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

Fig. 3.3—Relationship between elevation and percent cover in 

tree-dominated pinyon-juniper woodlands. Adapted from Tausch 

and Tueller (1990).

mature woodlands is currently expanding faster than it is 

being lost from wildfi re, but this net trend shows signs of 

reversal (Tausch 1999a). Nationally, woodlands seem to 

be expanding at a decreasing rate, however. For example, 

the extent of pinyon-juniper ecosystems in the western 

United States is estimated to be 56 million acres (Mitchell 

and Roberts 1999), no more than inferred by Platt (1959) 

40 years ago. Pressures to control woodland trees over the 

next 50 years may shift to a strategy of restoring patch size 

distributions instead of controlling future expansions. 

Decline of Quaking Aspen

Quaking aspen (Populus tremuloides) stands have long 

been valued both for wildlife habitat and as a regionally 

important source of summer livestock forage (Ellison and 

Houston 1958). Forage biomass in some aspen stands 

can exceed 4,000 lb./ac. Species diversity indices of both 

plants (Houston 1954) and animals (Smith and MacMahon 1981) are relatively high in aspen communities, particularly when compared to surrounding coniferous communities. Quaking aspen has been cited as an excellent 

indicator of ecosystem integrity because the species does 

not establish from seed (Kay 1997).

Landscapes dominated by quaking aspen receive 

exceptionally high recreational use during early fall when 

the trees’ leaves turn a brilliant gold. Tours, festivals, 

and other activities highlighting aspen may be found 

throughout the Rocky Mountains from mid-September 

to mid-October each year. Although the scenic value of 

aspen communities may now exceed commercial uses, 

very little research has been conducted to assess its aesthetics (Johnson et al. 1985).

The quaking aspen type extends from eastern Canada 

to Alaska, and southward to Mexico in the western United 

States (Jones 1985). Mueggler (1985) has summarized 

aspen-dominated vegetation associations in the Northern, Central, and Southern Rocky Mountains, Colorado 

Plateau, Black Hills, Northern Great Plains, and Sierra 

Nevada Mountains. The largest clones and most extensive distribution of aspen are in the Colorado Plateau 

states of Utah and Colorado. In the early 1980’s, quaking 

aspen occupied 7.1 million acres in the RM Assessment 

Region (Green and Van Hooser 1983).

Aspen reproduction is unique from other montane 

trees in that it sprouts vegetatively from a persistent 

parent root system. Such reproduction can only be triggered by disturbance, primarily fi re. Most aspen communities are considered seral, and will slowly be replaced by 

conifers or sagebrush/grass with a lack of disturbance. 

Thus, recurring fi res have maintained the abundance of 

aspen in the western United States, even though the transition to a different community-type can take more than 

500 years (Jones and DeByle 1985).

Historical research has confi rmed that fi re frequency 

has greatly decreased in aspen in the same manner it has 

within other western forest and woodland zones since the 

mid 19th Century (Baker 1925, Bartos and Campbell 1998). 

As the interval between fi res lengthens, aspen is more 

prone to be eliminated from the landscape because the 

competitive edge of vegetative over sexual reproduction 

is forfeited in the absence of periodic disturbance (Noble 

and Slatyer 1980). Aspen stands are not easily burned, so 

continued overgrazing by domestic livestock, deer, and 

elk can exacerbate the lack of fi re by reducing fi ne fuels 

(Jones and DeByle 1985). In addition, browsing of suckers 

by livestock and wildlife can directly thwart regeneration 

of quaking aspen (Kay 1997, Suzuki et al. 1999).

As a consequence of past domestic grazing practices, 

expanding populations of elk and deer, and a long-term 

strategy of quickly fi ghting all forest fi res, the abundance of quaking aspen has dramatically declined in the 

last century. Bartos and Campbell (1998), using Forest 

Inventory and Analysis (FIA; Rocky Mountain Research 

Station, 507-25th St., Ogden, UT 84401) data on size 

and distribution of existing stands, estimated that quaking aspen has declined by 60 percent to a present area 

of 800,000 acres on NFS lands in Utah. O’Brien (1999) 

reported aspen declined from 2.9 million acres to 1.4 mil75

45

15

2000 2100 2200

Elevation (m)

Cover (%)

2300
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 47

Rangeland Health CHAPTER 3

Table 3.26—Decline in area of quaking aspen (Populus tremuloides) in eight Rocky Mountains Assessment Region states 

from historical levels in the mid-19th Century.

 Area Occupied (acres 103

)

State Historical Area Current Decline (%)

Arizona 721 29 96

Colorado 2,188 1,111 49

Idaho 1,610 622 61

Montana 591 211 64

Nevada N/A 119 —

New Mexico 1,142 140 88

Utah 2,931 1,428 51

Wyoming 436 204 53

Total1

 9,619 3,745 61

N/A = Not available.

1

 Not including Nevada

Source: D.L. Bartos, Rocky Mountain Research Station, Logan, UT. Data 

are originally from the Forest Inventory and Analysis Work Unit, Rocky 

Mountain Research Station, Ogden, UT.

lion acres on all lands in Utah, a loss of slightly more 

than 50 percent.

Historical estimates of quaking aspen abundance were 

obtained by FIA following an algorithm with the following assumptions: Aspen clones cannot regenerate once 

the parent root system dies; one or more aspen stumps or 

logs denote a former clone; and the size of aspen clones 

has not signifi cantly changed over the past several hundred years. As a result, the historical area occupied by 

quaking aspen can be estimated by concluding that each 

location where stumps or logs of dead aspen are found 

supported an average-sized aspen clone. Based upon FIA 

data provided by D.L. Bartos (Rocky Mountain Research 

Station, 860 N. 12th East, Logan, UT 84321) and this algorithm, we estimate that west-wide, quaking aspen has 

declined by 60 percent since settlement by Europeans 

(table 3.26).

Whether the downward trend in quaking aspen abundance can be reversed will depend upon proper livestock 

grazing plans, the ability to control excessive browsing 

by wildlife, and our ability to restore natural regeneration 

using silvicultural techniques such as clearcutting, fi re, 

and the use of herbicides (Schier et al. 1985). With declining public support for clearcutting and the use of chemicals, increasing populations of deer and elk (Flather et 

al. 1999), and the high cost of prescribed fi re in forested 

ecosystems, there is no reason to expect the rate of aspen 

decline to markedly change over the next 50 years.

Non-Indigenous Plants

The spread of plant and animal species outside their 

historic home ranges constitutes an important indicator 

of forest and rangeland ecosystem health and vitality 

(USDA Forest Service 1997). On a global scale, biological 

invasions of non-indigenous species not only are disrupting natural ecosystems, but are to a greater and greater 

degree threatening human health and burdening economies (Vitousek et al. 1996). The invasion of non-native 

plants onto forests and rangelands has been likened to 

wildfi res wherein entire areas have been made useless in 

a comparatively short period of time, requiring the same 

form of open-ended funding to control (Westbrooks 1998). 

Bright (1998) declared bioinvasions to be a form of evolution-in-reverse because human activities have negated 

the effectiveness of barriers isolating thousands of particular ecosystems around the world.

Exotic or non-indigenous plants are species that have 

been introduced into ecosystems in which they did not 

evolve, and, consequently, tend to have no natural enemies to limit their reproduction and expansion. Where 

introduced, they tend to be more vigorous and taller, 

producing more seeds, than in their native environment 

(Crawley 1987). Invasive plants fall largely under the 

ruderal and competitive life history strategies proposed 

by Grime (1977); ruderal where weeds appear after disturbance, and competitive where they are better adapted 

to conditions of low stress and low disturbance. Noble 

(1989) identifi ed two strategies for invading habitats 

where native species are displaced: where the invader is 

a superior competitor, and where the invader has characteristics permitting it to survive under unique conditions 

such as extreme events.

Alien plants have both environmental and economic 

consequences to those managing rangelands. They displace native species, even those fi rmly established, and 

alter ecosystems principally through stand renewal and 

successional processes (Young and Longland 1996). Exotic 

species are invasive in that they can spread quickly, even 

though the ecosystem may be in good ecological condition 

(Tyser and Key 1988), although conclusive evidence supports the premise that disturbance almost always has some 

role in promoting biological invasions (Rejmánek 1989). All 

things considered, perhaps every rangeland ecosystem has 

been disturbed to some degree (Pickett and White 1985).

Non-indigenous plants have been shown to hybridize 

with native species, an insidious process that lessens the 

distinction between alien and non-alien species (Abbott 

1992). Hybridization may become especially destructive 

in designated wildernesses and other protected areas 

(Cole and Landres 1996).

From a legal point of view, noxious weeds are different 

from non-indigenous plants. The former consist of spe-
48 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

cies that are offi cially listed by a state or county, usually 

under the purview of state law, for the purpose of their 

control. Species on noxious weeds lists are usually nonindigenous, but not always. This section deals with nonindigenous invasive plants.

The prevalence of invasive non-native plants on U.S. 

grazing lands became broadly understood in the early 

1990’s with the publication of a comprehensive report 

by the U.S. Congress, Offi ce of Technology Assessment 

(1993). By 1998, 17 federal agencies reached an understanding to form the Federal Interagency Committee for 

Management of Noxious and Exotic Weeds (1998). The 

Committee was established to develop an integrated ecological program to manage noxious and exotic weeds on 

federal lands, and provide technical assistance to private 

landowners (Westbrooks 1998). On 3 February 1999, President Clinton issued an executive order establishing a 

cabinet-level Invasive Species Council to provide national 

leadership in controlling and managing invasive species.

Land managers now rank weeds among their most burdensome problems; more than 1 in 10 stewards of lands 

owned by The Nature Conservancy have identifi ed weeds 

as their worst management problem (Randall 1996).

The ratio of non-native species to all fl ora varies globally 

by region from 1 percent in the Mediterranean region to 

nearly 50 percent in New Zealand (Quezal et al. 1990, Heywood 1989). Regions dominated by deserts and savannas 

are less infl uenced than more mesic regions, as is the eastern hemisphere in comparison to the western hemisphere. 

Within continents, the degree of invasion rises with latitude 

(Lonsdale 1999). There is confl icting evidence concerning 

the positive vs. negative relationship between invasibility 

and biodiversity (Tilman 1997, Lonsdale 1999), although 

the differences may be related to scale. Stohlgren et al. 

(1999) concluded that exotic species are more likely to 

invade areas of high species richness at the landscape and 

biome levels because both biodiversity and invasibility are 

positively correlated with resource richness. 

Canada and the United States each have about 2,000 

non-indigenous invasive plant species, although within 

the United States these species are concentrated in three 

states—California, Florida, and Hawaii (U.S. Congress, 

Offi ce of Technology Assessment 1993). According to one 

review, non-indigenous plants comprise 14 percent of all 

species in the Great Plains (Rejmánek and Randall 1994). 

Even though much of the mid- and tall-grass prairies 

have been planted to agronomic crops for many years, 

it is not unreasonable to expect associated grasslands to 

have a similar percentage of alien species. 

Non-indigenous weeds are rapidly escalating on U.S. 

rangelands. During the 19th Century, 90 to 120 new species were introduced per decade in the Pacifi c Northwest. The decennial rate of new non-indigenous species 

declined to as low as 30 species during the 1930’s and 

1940’s, however, before closing in on the previous frequency of introductions in the mid-20th Century (fi gure 

3.4). Expanding global commerce and travel are certainly 

the major causes of the recent expansion. Interestingly, 

the fi rst surge of invasive plant species tended to be annuals, while greater proportions of perennials, including 

woody plants, characterize species introductions during 

the latter 20th Century (Toney et al. 1998).

The USDI Bureau of Land Management (1996a) Action 

Plan alluded to information showing that weeds have 

seriously infested 8.5 million acres, or 5 percent, of BLM 

lands. However, they estimated the area impacted to be 

increasing at a rate of 2,300 acres/day, an amount that 

would bring the area of BLM lands infested to approximately 19 million acres by the year 2000. The same reference predicted an infestation rate for all public lands in 

the West to be double that found on BLM lands—4,600 

acres/day—leading to a total wildland infestation of 33 

million acres by the year 2000.

Although there is little doubt that invasive weeds have 

been increasing in abundance across U.S. grazing lands, no 

sources of data exist that can be agglomerated to estimate 

the total magnitude of infestation. Information from both 

published and unpublished sources is summarized by species below. Still, one can logically surmise that the gravity 

of the present non–indigenous rangeland weed situation 

cannot be adequately characterized by aggregating material that is neither current nor collectively exhaustive.

Leafy Spurge

Leafy spurge (Euphorbia esula) is a deep-rooted perennial 

forb with milky sap that forms expansive dense patches. It 

is diffi cult to control because of its extensive root system 

and its ability to spread by seed. The species has spread 

widely, from coast to coast across the northern United 

States over the past 80 years. Twenty years ago, leafy 

140

77 87 97 07 17 27 37

Last year of decade (1877-1997)

47 57 67 77 87 97

No. of new species invading

per decade

120

100

80

60

40

20

0

Fig. 3.4—Invasion of non-indigenous weeds, by decade, in 

Washington, Oregon, Idaho, Montana and Wyoming. Unpublished data from testimony of Peter M. Rice, University of 

Montana, to the Senate Agriculture Committee, 8 May 1999, 

Nampa, ID.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 49

Rangeland Health CHAPTER 3

100

60

20

90

50

10

80

40

0

0 10 20 50 30 40 70 90 60

Leafy spurge infestation (%)

Wildland wildlife habitat value (%)

80 100

70

30

Fig. 3.6—Relationship between leafy spurge infestation and 

wildlife habitat value. Adapted from Leistritz et al. (1993).

2,000

1,500

1,000

500

0

1960

With successful

biological control

Without successful

biological control

1970 1980 1990 2000 2010 2020 2030

Year

Acres x 103 Fig. 3.7—Historic and projected extent of leafy spurge infestations in the Northern Great Plains. Adapted from Bangsund et 

al. (1999).

100

90

80

70

60

50

40

30

20

10

0

0 10 20 30 40 50

Available carrying capacity (%)

Leafy spurge infestation (%)

60 70 80 90 100

Fig. 3.5—Relationship between leafy spurge infestation and 

rangeland livestock carrying capacity. Adapted from Leistritz et 

al. (1993).

spurge was reported in 458 counties in 26 states (Dunn 

1979). The species expanded in a linear fashion into new 

counties in Montana and surrounding states until the mid1980’s, after which it mushroomed exponentially (unpublished data from the Invaders data base; see <http://

invader.dbs.umt.edu>). Lym (1991) applied data in Dunn’s 

paper to estimate the extent of leafy spurge in the Northern 

Great Plains, including Canada, at 2.7 million acres. 

Leafy spurge, like other alien invasive weeds, costs 

rangeland owners and managers directly through decreased grazing capacity (fi gure 3.5) and wildlife habitat 

(fi gure 3.6). Weeds also generate secondary costs through 

lost jobs and reduced spending by visitors. The direct and 

secondary economic impacts of leafy spurge in the Upper 

Midwest, alone, were estimated to be $120 million in 1993 

(Leitch et al. 1996).

Regardless of the exponential increase in leafy spurge 

over the latter half of the 20th Century, some experts 

expect the rate of growth will slow and even decrease 

over the next 30 years in the Northern Plains because the 

species has already occupied much of the areas in which 

it is best adapted (fi gure 3.7). The actual future expanse of 

leafy spurge will depend, as with other invasive plants, 

upon the success of biological control measures (Bangsund et al. 1999).

Knapweeds and Starthistles

About 15 species of knapweeds and starthistles (Centaurea spp.) have invaded U.S. rangelands. The genus 

originated in the Mediterranean region. Among the most 

signifi cant invaders are spotted knapweed (C. maculosa), 

diffuse knapweed (C. diffusa), Russian knapweed (C. 

repens), and yellow starthistle (C. solstitialis). As a group, 

these species are deemed as being harmful to rangelands 

because they often invade communities that are in relatively good condition, cause sites to be more erodible, and 

provide little forage or wildlife habitat value (Lacey et al. 

1989, Roché and Roché 1991). 

Centaurea spp. have replaced native species on millions 

of acres of rangeland in western North America (Lacey 

and Olson 1991). The four species listed above occupy at 

least 20 million acres by themselves (table 3.27). The eco-
50 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

nomic impact of knapweeds and yellow starthistle upon 

rangeland is severe, especially where they have taken 

over productive sites. In Montana alone, losses in forage 

value amounted to more than $10.50 per infested acre in 

1994. Total economic costs in Montana, including those 

associated with grazing, wildlife habitat, and soil and 

water conservation, were estimated at $14.1 million annually during the same year (Hirsch and Leitch 1996).

Knapweeds and yellow starthistle are primarily controlled with chemicals (Sheley and Jacobs 1997), but 

chemical control is only cost-effective on productive sites 

where increased forage production can adequately compensate for the cost of treatment (Griffi th and Lacey 1989). 

Integrated control measures, involving biological agents, 

grazing, fi re, and chemicals, are seen as a more long-term 

solution to the problem (Hrubovcak et al. 1999). Although 

phytophagous insects to control knapweed were introduced as far back as the 1970’s (Müller et al. 1988), 

research has shown that the introduction of natural enemies alone does not commonly reduce Centaurea spp. 

dominance, and can even decrease the competitive ability 

of associated native plants (Callaway et al. 1999).

No quantitative approaches are available to project the 

spread of Centaurea spp. in the United States. Chicoine et 

al. (1985) estimated spotted knapweed was expanding at 

an approximate rate of 25 percent per year in Montana, 

and that the species had the potential to increase from 2 

million acres at the time of their work to 35 million acres. 

The real uncertainty with Centaurea spp., as with other 

non-indigenous plants, lies with understanding how far 

and to what extent they will spread beyond the ranges in 

which they are found now.

Saltcedar

Saltcedar (Tamarix spp.), an aggressive phreatophyte, 

was fi rst introduced into the United States as an ornamental in the early 19th Century (Horton 1964), but has 

been a robust invader of riverine and riparian rangeland 

ecosystems during the past 60 years (Busby and Schuster 

1971, Di Tomaso 1998). In the Southwest, particularly, 

Table 3.27—Area occupied by four non-indigenous noxious species of Centaurea in the western United States. From Lacey and 

Olson (1991).

 Area occupied

Common name Species (acres 106

)

Spotted knapweed C. maculosa 7.3

Diffuse knapweed C. diffusa 3.2

Russian knapweed C. repens 1.4

Yellow starthistle C. solstitialis 9.4

saltcedar has replaced more benign native phreatophytes 

such as cottonwoods and willows (Busch and Smith 1995). 

In some areas, water management practices and dam 

construction have dropped fl oodplain water tables and 

stopped recurring scouring of river banks, thus further 

reducing the competitiveness of native woody species 

(Howe and Knopf 1991). With its extremely high transpiration rate and capability for osmotic adjustment, saltcedar, once established, can depress the water table by 

itself, giving the species an added competitive advantage 

over native phreatophytes because of its higher water use 

effi ciency (Davenport et al. 1982, Busch and Smith 1995). 

Robinson (1965) calculated that a dense 1-acre stand of 

saltcedar is capable of transpiring 11,100 m3

 (9 acre-feet) 

of water annually.

The present extent of saltcedar is not precisely known. 

More than 30 years ago, Robinson (1965) showed Tamarix spp. to be established in every conterminous state 

west of the 95th Meridian except North Dakota, Idaho, 

and Washington, occupying 1.5 million acres. Like other 

rangeland weeds, saltcedar has expanded exponentially 

within some parts of its range (fi gure 3.8). It now 

is found along the main branches and tributaries of 

the Snake and Columbia Rivers in Idaho and Washington (unpublished data from the Invaders data base), 

as well as in North Dakota (unpublished data from 

the PLANTS data base, see <http://plants.usda.gov/

plantproj/plants/index.html>).

1910

Total area,

light, medium and dense cover

Medium and dense cover

0

10

20

30

40

50

60

1920 1930 1940

Year

Area, in thousands of acres

1950 1960

Fig. 3.8—Expansion of saltcedar along a 200-mile reach of the 

Pecos River in southeastern New Mexico. Adapted from Robinson (1965).
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 51

Rangeland Health CHAPTER 3

Controlling saltcedar will not be an easy task. U.S. 

Congress, Offi ce of Technology Assessment (1993) cited 

a Bureau of Reclamation report estimating the cost of 

restoring native phreatophytes to the lower Colorado 

River to be as much as $450 million. The species is resistant to herbicides and root-plowing because of its ability 

to sprout following treatment (Kerpez and Smith 1987). 

Non-Indigenous Thistles

Thistles are somewhat of an anomaly. While the majority of thistles are native to the United States, occurring 

inconspicuously from low to mid-montane elevations 

across wide regions, a few introduced Eurasian species are 

among the most deleterious of weeds on western rangelands (Dewey 1991). Canada thistle (Cirsium arvense) has 

been declared a noxious weed in at least 35 states from 

California to Maine and Washington to Georgia. Musk 

thistle (Carduus nutans) has been so designated in half as 

many states in every U.S. region except the Southeast. 

A third thistle, Scotch thistle (Onopordum acanthium) is a 

major invader of rangelands in the PC Assessment Region. 

Invasive thistles are biennials or short-lived perennials.

No one knows the extent of alien thistle populations 

on U.S. rangelands. In montane regions, Canadian thistle 

can dominate the understory after logging, but lose out 

to native species after a few years. Whether or not such 

areas of transient dominance should qualify in assessing 

the health of grazing lands is unclear. In other areas, thistles persist for years after disturbance. 

Colleagues at the Department of Bioagricultural Sciences and Pest Management, Colorado State University, 

and I conducted a survey of state weeds specialists in 

1997. With reference to Canadian thistle, we received estimates from seven RM Assessment states (ID, KS, ND, NE, 

SD, UT, WY), fi ve states in the NO Assessment Region 

(DE, MN, NH, NJ, PA) and two states in the SO Assessment Region (FL, LA). The specialists conjectured that 

a total of 3.0 million acres of Canadian thistle could be 

found in their states, which collectively comprise 27 percent of the land mass of the conterminous 48 states. The 

invaded area equaled 0.6 percent of the area of these 14 

states, ranging from <.01 percent in Kansas and Wyoming 

to 4 percent in Delaware and Pennsylvania (May 1999). 

Even if the above estimates exceeded actual infestations 

by a factor of two, extrapolation implies that Canada thistle would still occupy nearly 6 million acres in the conterminous United States.

Purple Loosestrife

Although wetlands, marshy sites, and riparian zones 

comprise a small part of rangeland landscapes in the 

United States, their sustainability is essential for the maintenance of biodiversity, clean water supplies, wildlife habitat, recreational opportunities, and as a forage supply for 

both wild and domestic grazing animals. Purple loosestrife (Lythrum salicaria), a colorful, tall perennial herb 

from Europe, has invaded wetlands in nearly every U.S. 

region and Canada, particularly across the northern tier 

of states. It is listed as a noxious weed in 24 states (Westbrooks 1998). The species has expanded rapidly westward since the early 1940’s, but new infestations have 

been most remarkable in western states from California 

to Montana (Thompson et al. 1987). 

Once established, purple loosestrife forms dense, mono -

typic stands that decimate biodiversity, wildlife habitat, 

and forage value (Malecki et al. 1993). It is highly competitive in multiple environments, fertile vs. unfertile, 

drained vs. fl ooded (Keddy et al. 1994). The weed’s ability to invade infertile habitats is particularly detrimental 

for threatened and endangered wetland plants because of 

the propensity of rare plants to occupy such sites (Moore 

et al. 1989). 

Purple loosestrife reduces U.S. forage supplies in two 

ways: by replacing palatable graminoid and forb species 

in wet meadows that are grazed or hayed, and by clogging irrigation ditches that deliver water to forage-producing land (Mullin 1998). No actual data delineate the 

area of wetlands infested or biomass of forage lost because 

of purple loosestrife.

Cheatgrass

Cheatgrass (Bromus tectorum) is a winter annual grass 

that invaded from the Mediterranean region in the mid19th Century (Klemmedson and Smith 1964). It is now 

widely distributed throughout North America, where it 

occurs in every U.S. state, Canada, and Mexico (Westbrooks 1998). Mack (1981) has suggested that cheatgrass 

is universally present on 100 million acres of steppe vegetation within the RM and PC Assessment Regions alone. 

Cheatgrass is so ubiquitous that, more than any other 

species, it may have fostered the concept of PNC as a 

replacement for climax in successional theory (fi gure 3.9). 

Aldo Leopold (1949) captured the idea of cheatgrass’

unpretentious, yet total, occupation of rangelands in an 

essay called “Cheat Takes Over” when he stated that “one 

simply woke up one fi ne spring to fi nd the range dominated by a new weed.”

The abundance of cheatgrass has caused some livestock producers to use it as a source of early spring 

forage. Cheatgrass provides a balanced ration in early 

spring before perennial grasses commence growth (Cook 

and Harris 1952). The disadvantage of grazing cheatgrass 

lies in its extreme fl uctuations in production from year 

to year. Nonetheless, the species is unique among non-
52 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

Table 3.28—List of non-indigenous weed species not described in document text.

Common Name Scientifi c Name Distribution Reference

Medusa head Taeniatherum aspeum PC, RM Hilken and Miller 1980

Perennial Pepperweed Lepidium latifolium PC, NO, SO Young et al. 1998

Mediterranean sage Salvia aethiopis PC, RM Roché and Wilson 1999

Russian olive Elaeagnus umbellata U.S. Olson and Knopf 1986

Dalmatian toadfl ax Linaria dalmatica PC, RM Alex 1962

Yellow toadfl ax Linaria vulgaris PC, RM Saner 1994

Whitetop Cardaria pubescens PC, RM, NO Sheley and Stivers 1999

Rush Skeletonweed Chondrilla juncea PC, RM Heap 1993

Oxeye daisy Chrysanthemum leucanthemum PC, RM, NO Olson and Wallander 1999

Hounds tongue Cynoglossum offi cinale PC, RM Upadhyaya et al. 1988

Tanzy ragwort Senecio jacobaea PC, RM McEvoy et al. 1991

Kudzu Pueraria lobata SO, NO Miller and Edwards 1982

Mile-a-minute Polygonum perfoliatum SO, NO McCormick and Hartwig 1995

1.0

0.8

0.6

0.4

0.2

0.0

1890 1900 1910

Year

Proportion of Total Range Occupied

1920 1930 1940

Fig. 3.9—Expansion of cheatgrass (Bromus tectorum) throughout its eventual range in the United States. From Mack (1981).

indigenous weeds as being both managed for and managed against, depending upon the circumstances. 

Cheatgrass has a profound effect on sagebrush-grass 

rangelands by replacing perennial native grasses. It does 

so by extending its root growth through the entire soil 

solum during winter months, then extracting all soil 

water in the spring, causing perennial grass seedlings to 

die (Harris 1967). Once it becomes established, cheatgrass 

creates a positive feedback in association with wildfi re by 

depleting the vigor and abundance of perennial grasses. 

Cheatgrass allows hot fi res to occur earlier in the spring 

when perennial grasses are physiologically susceptible to 

burning (Wright and Klemmedson 1965). The resulting 

extended fi re season, in turn, creates conditions for cheatgrass to maintain dominance. Overgrazing exacerbates 

these dynamics (Pechanec et al. 1954). 

In pinyon-juniper woodlands, cheatgrass and fi re can 

jointly create a threshold that prevents re-establishment 

of the original woodland. Tausch (1999b) has submitted 

that a number of woodland and sagebrush rangeland ecosystems in the Great Basin have crossed thresholds created by non-indigenous species, but the full effect of these 

species are as yet unknown.

Other Non-Indigenous Weeds

The species described above may be the most prevalent weeds on U.S. rangelands, but a number of other 

invasive plants pose present or potential problems to 

agency managers and private landowners alike. A short 

and non-exhaustive listing of other weeds is presented in 

table 3.28. The Council for Agricultural Science and Technology (CAST) has published an issue paper on invasive 

plant species that contains a list of 60 rangeland/wildland 

economically and ecologically important invasive weed 

species in the United States (CAST 2000).

Non-Indigenous Weeds on National Forest 

System Lands

Estimated weed abundance is shown, by Forest Service Region, in table 3.29. The supporting data for the 

totals shown were derived from expert-opinion estimates 

at the individual National Forest level. 

As can be seen from the median estimates, distributions are highly skewed among Forests within Regions 

and among Forest Service Regions within the United 

States. For example, in the NO Assessment Region about 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 53

Rangeland Health CHAPTER 3

Table 3.29—Total area infested by non-indigenous weeds on 

National Forest System lands, by Region, and area infested by 

median National Forest in Region, 1998.

Forest Service Region Area (ac. 103

)

Northern, R-1 1,181.1

Median Forest (n = 13) 40.0

Rocky Mountain, R-2 376.2

Median Forest (n = 10) 23.6

Southwestern, R-3 193.8

Median Forest (n = 11) 2.0

Intermountain, R-4 805.0

Median Forest (n = 14) 26.2

Pacifi c Southwest, R-5 60.6

Median Forest (n = 12)1

 2.6

Pacifi c Northwest, R-6 454.8

Median Forest (n = 20) 10.0

Southern, R-8 200.0

Median Forest No data

Eastern, R-9 295.6

Median Forest (n = 15) 13.5

Total, All Regions 3,567.1

Median Region (n = 8) 335.9

1

 Two forests and the Lake Tahoe Basin Management Unit did not report 

weeds data.

two-thirds of all NFS lands infested with non-indigenous 

weeds can be found on three National Forests, the Bitterroot, Idaho Panhandle, and Lolo. In the Southwestern 

Region, a single National Forest, the Coconino, accounted 

for almost 90 percent of all infested acres reported (unpublished data). The lack of spatial evenness seems to be a 

characteristic of weeds at different spatial scales, especially at regional and national levels (see discussion 

above, Rejmánek and Randall 1994, Lonsdale 1999).

Future Impacts of Non-Indigenous Plants

The future extent of non-indigenous weeds in the 

United States will depend upon the rate that non-infested 

rangelands become occupied and the rate of recovery on 

lands already infested. Given that disturbance is a natural 

process on rangelands regardless of how they are managed, one can conclude that alien weeds will continue to 

invade into areas previously unoccupied. 

The potential for invading rangelands, either by new 

species or existing species from surrounding locations, 

is high. Increasing trade and travel will facilitate new 

pathways for species exchange across national borders, 

thereby exposing U.S. rangelands to weeds previously 

not seen (U.S. Congress, Offi ce of Technology Assessment 

1993). Broadened interest in ornamentals is allowing 

non-indigenous plants to escape into natural areas. For 

example, the forb Japanese knotweed (Polygonum cuspidatum) has escaped from urban landscapes in the Pacifi c 

Northwest and is rapidly escalating in riparian zones 

from Oregon to Montana (personal communication with 

Andrew Kratz, USDA Forest Service, Rocky Mountain 

Region, Denver, CO). It forms thick stands that are presently unaffected by hand treatments or herbicides.

Even though we should expect future non-indigenous 

weed invasions onto U.S. rangelands, drawing conclusions about potential patterns of plant invasions is not 

easy (Lonsdale 1999). Once a species is established, 

research can only sometimes appraise its potential for 

expansion into uninvaded areas (Chicoine et al. 1985). 

Some theoretical reaction-diffusion models of how invasive species spread have been validated as accurate, but 

others have been shown to have large error terms (Hastings 1996). Stochastic models may furnish better insight 

into modeling how weeds spread from initial invasion 

patterns. 

Reichard and Hamilton (1997) have advanced the possibility of being able to predict invasive success on the 

basis of plant attributes and climatic range. Under their 

proposed scenario, protocols could be developed to screen 

intentional introductions of alien species, leaving mostly 

the impacts from unintentional invasions to cause problems in natural ecosystems. However, Mack (1996) argued 

that predicting plant invasions is not easy because “climate-matching” fails to account for different biotic restrictions among regions, and models based upon initial 

rates of spread are inaccurate because they lack critical 

spatial pattern recognition. Mack called for experimental 

approaches to complement theoretical models for determining invasibility. Thus, our facility for forecasting weed 

invasions in order to mitigate future impacts is somewhat 

ambiguous.

Researchers are divided about the outlook for controlling invasions of non-native plants. When speculating 

about coming years, they tend to fall into the two camps: 

optimism and pessimism (U.S. Congress, Offi ce of Technology Assessment 1993). In general, those working in 

biological control research hold the encouraging perspective that biocontrol agents will hold down future impacts 

by up to one-third of introduced weed species (McFadyen 

1998). At the other end of the spectrum lie environmental 

organizations and many state and federal agencies that 

see invasive species increasing in a geometric progression 

(Williams 1997, Federal Interagency Committee for Management of Noxious and Exotic Weeds 1998). Some scientists are expecting a continuing wave of introductions 

from rangelands in other countries climatically similar to 

the United States such as China, South Africa, and Argentina (unpublished testimony of Peter M. Rice, University 

of Montana, to Senate Agriculture Committee, Hearing 

on Noxious Weeds, 8 May 1999, Nampa, ID).
54 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 3 Rangeland Health

The most likely outcome will lie between these two 

extremes. Several investigators working in biological control acknowledge the effectiveness of introduced organisms in successfully controlling some weeds like tansy 

ragwort (Senecio jacobaea)(McEvoy et al. 1991), but question whether simply adding natural enemies will check 

or reverse an invasion regardless of the local or environmental conditions, particularly in an uncertain future 

(McEvoy and Coombs 1999). 

Little work has been done on balancing the risks of 

introducing new releases versus the benefi ts accrued from 

such actions (Simberloff and Stiling 1996, Louda et al. 

1997). Rejmánek and Randall (1994) have demonstrated 

that the rate of non-indigenous species establishment is 

slowing somewhat in California, a state with one of the 

highest densities of alien species.

There is inadequate understanding about the degree 

to which episodic events such as droughts and extreme 

fi re years will accelerate the spread of non-indigenous 

weeds. For example, large areas of Nevada and adjoining 

Intermountain states burned during the summer of 1999, 

and some rangeland scientists are expecting cheatgrass 

to spread extensively in this region. Klemmedson and 

Smith (1964) and Young and Longland (1996) discussed 

how fi re can intensify the rate that cheatgrass increases in 

abundance and distribution. If infrequent episodic events 

do cause unforeseen levels of expansion by alien plants, 

present rates of increase may be maintained well into the 

21st Century.

Collectively, riparian and aquatic habitats are perhaps 

the most crucial rangeland ecosystems when it comes 

to invasibility. Purple loosestrife, Russian olive (Elaeagnus angustifolia), saltcedar, and Japanese knotweed have 

been rapidly spreading in these ecosystems (Cartron et 

al. 2000). A free-fl oating aquatic fern, giant salvinia (Salvinia molesta) has recently invaded ponds, oxbows, and 

slow-moving streams from the Atlantic Coastal Plain to 

central California. This weed can quickly form thick mats 

that threaten aquatic plant and animal life (Oliver 1993). 

Stohlgren et al.’s (1999) conclusion that plant communities with high canopy cover, soil fertility and species 

diversity are most likely to be hot spots for expanding 

exotics points to riparian zones as a potential target. Such 

a conclusion should be tempered with the understanding 

that not all riparian areas are exceptionally diverse when 

compared to other kinds of ecosystems (Baker 1990).

Summary

The status of our Nation’s rangelands can be ascertained on the basis of various standards. In general terms, 

rangeland health is connected to the broader concepts 

of sustainability and sustainable management. One standard, the Montreal Process (USDA Forest Service 1997), 

is appropriate for evaluating rangeland sustainability at a 

national scale through seven criteria: biological diversity, 

productive capacity, ecosystem health, soil and water conservation, contribution to the global carbon cycle, multiple socio-economic benefi ts, and a legal-institutional-economic framework (Mitchell et al. 1999a). The fi rst four 

criteria are summarized in turn below. Criterion 7 is the 

subject of Chapter 5. Insuffi cient information is available 

for an effective discussion of the other two criteria at this 

time.

Biological Diversity

Extent of area by rangeland type and successional 

stage is an important indicator of biological diversity. 

More than half of all the ecosystem types determined to 

be critically endangered (i.e., >98 percent of area has been 

lost or ecologically degraded) are grasslands or shrublands (Noss et al. 1995). This sum is weighted heavily, 

however, by the near-total disappearance of tallgrass prairie and extensive conversions of the mixed grass plains 

to agricultural use prior to the 1930’s (Samson and Knopf 

1994). Much of the remaining land base is stable. Additionally, some studies showing such total losses of native 

cover tend to overlook smaller tracts because of the large 

pixel size (1 km) used in data analysis (Sieg et al. 1999). 

Thus, rangeland type should be judged by both actual 

extent and long-term trend. There is no indication that 

endangered rangeland ecosystem types are now being 

lost except for desert grasslands (Schlesinger et al. 1990, 

Grover and Musick 1990, Loftin et al. 2000) and aspen 

(Bartos and Campbell 1998). 

The Nature Conservancy and other non-governmental organizations have been working to protect endangered ecosystems and enhance biodiversity by preserving critical ecosystems (Mitchell et al. 1999b). If pockets 

of threatened and endangered species are broadly distributed across the Great Plains, as may be the case (Sieg et al. 

1999), it may be possible to reclaim species biodiversity 

by a combination of ecosystem protection and good management.

Rangeland area by successional state has been 

addressed in this chapter. Recall that range health is 

closely correlated with species composition, which is tied 

to successional stage. Trends in range condition range 

from static to improving in the PC and RM Assessment 

Regions across all land ownerships. Overall the trend 

seems to be one of slow improvement since the last 

Assessment (Joyce 1989) except for a few arid and semiarid ecosystems that have already crossed thresholds 

where recovery to previously existing PNC’s is not fea-
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 55

Rangeland Health CHAPTER 3

Fig. 3.10—Land area burned in the United States, 1924 to 1997. 

Data from USDA Forest Service as presented by The Heinz 

Center (1999). The acreage covers lands managed by agencies 

in U.S. Department of Interior and U.S. Department of Agriculture, as well as private lands.

60

50

40

30

20

10

0

1924 1934 1944 1954 1964

Year

Acres x 106

1974 1984 1994

sible in the short term. Such ecosystems are mostly static, 

or in some areas such as those with extensive infestations 

of non-indigenous weeds, still declining. A dichotomy 

exists in the SO Assessment Region, where NFS grazing 

lands are in good condition and fairly static but non-federal land condition seems to be in a downward trend. 

Productive Capacity

National Montreal Process indicators for productive 

capacity address the area of rangeland and total biomass 

available for grazing, and the annual removal of forage 

compared to that determined to be sustainable. Monitoring and documenting these indicators are diffi cult, and 

have not been adequate (McArthur et al. 2000). However, given the projection that livestock utilization of grazing land will decrease in the PC, RM, and NO Assessment Regions and not change signifi cantly in the Southern Assessment Region (Van Tassell et al. 1999), we can 

expect that the overall U.S. productive capacity will not 

be degraded. 

Ecosystem Health

Three indicators gauge the maintenance of ecosystem 

health under the Montreal Process: Area and percent of 

rangeland affected by processes or agents beyond the 

range of historic variation; area and percent of rangeland 

subject to specifi c levels of air pollution or ultraviolet B 

that may cause negative ecosystem impacts; and area and 

percent of rangeland with diminished biological components indicative of changes in fundamental ecological 

processes (USDA Forest Service 1997). 

Invasions of exotic species, fi re, drought, and grazing 

are examples of agents and processes that have apparently occurred beyond their range of historic variation on 

U.S. rangelands during the past 150 years. Fire is a natural and important component of many U.S. rangelands, 

but fi re prevention and suppression programs over the 

past 70 years have resulted in a major shift in fi re frequencies (fi gure 3.10). Prolonged drought reduces plant cover, 

thereby increasing erosion potential over large areas following the drought (Thurow and Taylor 1999). Nonindigenous weeds and grazing also have been considered 

in this chapter.

The vast expanses and remoteness of rangelands, both 

in the United States and globally, create diffi culties in 

assessing these indicators of health and vitality. No 

national monitoring framework is in place to collect data 

on long-term and episodic processes and agents over 

time. The best data available for the ecosystem health criterion may be for its second indicator because of national 

networks to monitor air quality (Joyce et al. 2000).

Soil and Water Conservation

A number of indicators have been developed as part 

of the Montreal Process for evaluating how well a nation 

maintains its soil and water resources. Among them are 

the area and percent of rangeland with signifi cant soil 

erosion and percent of stream length in which stream fl ow 

and timing have signifi cantly deviated from the historic 

range of variation (USDA Forest Service 1997). National 

data sets do exist for soils, water quality, and streamfl ow, 

but they have such varying degrees of coverage, compatibility, and recency that comprehensive analyses of them 

are problematic (Neary et al. 2000). The Proper Functioning Condition approach for rating the health and functioning of riparian zones, described above, could well 

serve as an adequate method for reporting the percent 

of stream reaches with abnormal stream fl ow and timing 

(Neary et al. 2000).

No hard rules exist for summarizing these or other criteria to determine rangeland health. Individual conclusions will vary from person to person and organization 

to organization. Thus, any collective overview can only 

be reached through values and objectives of society as 

expressed in goals and objectives, primarily through society’s refi nement process of laws and regulations (Shields 

and Mitchell In press). 

USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 57

Introduction

The Assessment required in the Forest and Rangeland 

Renewable Resources Planning Act of 1974 (RPA) is to 

include “an analysis of present and anticipated uses, 

demand for, and supply of renewable resources.” Forage 

supplies, in particular grazed forages, comprise the predominant renewable resource on rangeland, although 

other resources such as wildlife habitat, water, timber, 

minerals, and recreational opportunities are also jointly 

provided. Collectively, forage and other resources characterize a nation’s rangeland productive capacity.

Numerous factors are correlated with and affect the 

value of grazed forages. The future supply of forage is a 

function of changes in forage productivity and the extent 

of land available to produce forage (Joyce 1989). Quantifying either of these factors is not a trivial task, however. Across broad scales, primary production on rangelands is limited by fairly constant abiotic factors such as 

mean annual precipitation, potential evapotranspiration, 

temperature, and soil texture (Webb et al. 1983, Sala et 

al. 1988, Epstein et al. 1997). Therefore, any increases 

in production will rely upon advances in technology, 

rangeland restoration based upon existing technology 

that largely rely upon increasingly uneconomical energy 

inputs (Workman and Tanaka 1991), and/or substantial 

and widespread changes in rangeland health (Committee 

on Rangeland Classifi cation 1994). 

Technological developments can be analyzed within 

the framework of Criterion 6 (Maintenance and enhancement of long-term multiple socio-economic benefi ts to 

meet the needs of societies) and Criterion 7 (Legal, institutional and economic framework for forest conservation 

and sustainable management) of the Montreal Process 

(Coulombe 1995). For example, as applied to rangelands, 

Indicator 38 under Criterion 6 would assess the value of 

investment in rangeland health and management, livestock processing, and recreation and tourism. Indicator 40 

refers to the extension and use of new and improved technology. The extent to which the U.S. institutional framework has the capacity to develop and maintain an effi -

cient physical infrastructure to facilitate the supply of 

rangeland products and services is accounted for in Indicator 56 under Criterion 7 (USDA Forest Service 1997).

Joyce (1989) estimated that technology could result in 

a doubling of forage production in the Southwest and 

Pacifi c Northwest by the year 2040. As a result, U.S. 

rangelands as a whole were expected to have the capabilChapter 4: Maintenance of Productive Capacity

ity for substantially increasing forage productive capacity. Joyce’s deduction was made in part on the basis of a 

2 percent annual growth in research, development, and 

extension expenditures, and expected gains in technologies originated for croplands that could have applications 

for boosting pasture and rangeland forage production.

The average annual growth of real output per capita 

has increased in nearly every country since the end of 

World War II. The growth has been fueled by expanding 

access to education, increased savings and investments, 

advances in technology, and better integration of countries into the world economy (Bayoumi 1995). At the same 

time, however, commitments to science and technology 

are becoming less prominent among some U.S. mission 

agencies, a circumstance that could foretell a slowing 

of our international involvement in this arena (Watkins 

1997). Given the myriad and varied changes around the 

world during the past decade, it is appropriate to revisit 

how changing technology may or may not affect future 

rangeland forage production. 

Improving rangeland health relies more heavily on 

using ecological tools rather than advances in technology (Heady and Child 1994). From a national perspective, measures of rangeland health are found within two 

Montreal Process criteria, Criterion 2, productive capacity, and Criterion 3, maintenance of ecosystem health 

(McArthur et al. 2000, Joyce et al. 2000). Factors to be 

evaluated within these domains include the total biomass 

from rangeland available for grazing, removal of rangeland biomass and other products compared to the level 

determined to be sustainable, the infl uences of processes 

or agents beyond the range of historic variation, effects 

of air pollutants on rangeland function, and the area of 

rangeland with diminished biological components.

Advances in Technology

Research and Development Budgets

National budgets for research and development (R&D) 

face uncertain futures in many developed countries at 

the close of the 20th Century. In the U.S., federal research 

funds outside of those allocated for health issues face 

nearly continuous scrutiny because of political desires to 

decrease spending while simultaneously funding specifi ed domestic programs such as highways (Lawle 1998). 
58 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 4 Maintenance of Productive Capacity

The European Union’s research itinerary for the years 

1998–2002 may be reduced $1.9 billion from what was 

proposed by their Commission (Williams 1998). Recent 

fi nancial crises in east Asian countries are combining 

with their culture of science to at least temporarily limit 

R&D, even in those countries that have a recent history of 

emphasizing research in their development plans (Mervis 

and Normile 1998).

National funding for R&D is always expected to rise 

and fall with recessions. Longer term trends will likely 

depend upon factors such as the peace dividend, aggregate 

savings, possible debt crises, and global economic integration. No obvious future global tendencies for these factors have been documented. Even under conditions of low 

infl ation and a large government budget surplus, federal 

research spending faces an uncertain fate as long as social 

programs such as Social Security and Medicare appear to 

be in long-term jeopardy (Mervis and Malakoff 1999).

Although worldwide military spending decreased by 

3 percent of gross domestic product (GDP) between 1985 

and 1995, the resultant “peace dividend” of about $345 billion has been largely returned to the private sector through 

lower defi cits or lower taxes instead of being used to 

increase other spending (Clements et al. 1997). A number 

of low-intensity national confl icts during the 1990’s has 

increased the world demand for arms, thus helping 

blunt any tendency for decreased arms spending (United 

Nations 1997). On the other hand, at least one simulation 

analysis indicates that the GDP is an unreliable estimator 

of economic benefi ts accruing from military spending cuts, 

and that lower taxes and government spending reduce 

interest rates, which cause private sector spending on 

investment and consumption (including R&D) to be notably increased (Arora and Bayoumi 1994).

Nations’ gross national savings are generally seen as 

being important to help sustainable growth. Over the past 

25 years, savings rates of both industrial and developing 

countries, including the United States, have dropped 

abruptly (Aghevli and Boughton 1990). Whether this 

downswing will greatly infl uence the long-term growth 

rates or domestic investments depends upon government 

policy and other factors, however (Bayoumi 1990).

The inability of developing countries to service their 

debts can deny access to private international capital, 

possibly leading to the incapacity to carry out R&D programs over an extended period (Fischer and Husain 

1990). A number of economically developing countries 

with important rangeland bases are presently classifi ed 

as severely indebted: Argentina, Ethiopia, Kenya, Mexico, 

and Russia (Ahmed and Summers 1992).

Economic integration, the ratio of international trade 

to GDP, has been seen as a reliable indicator of a country’s 

participation in the world economy and, thus, its exposure to new technology (Brahmbhatt and Dadush 1996). 

Integration of most countries has risen rapidly in recent 

years, in great part because of liberalization actions precipitated by the General Agreement on Tariffs and Trade 

(GATT) and the international structure of private corporations (Qureshi 1996). Whether the fi nancial integration 

of developing countries as a whole will continue is yet 

to be seen. While the developed world as a whole has 

become more integrated, the extent and rate of integration varies widely among developing countries (Brahmbhatt and Dadush 1996).

Progress in crop production technology faces a less 

clear situation than was prevalent one decade ago. Recent 

World Bank studies indicate that global agricultural production growth rates slowed from 3.0 percent in the 

1960’s to 2.0 percent during 1980–92, and this percentage 

is expected to slip to 1.8 percent by 2010 (Ruttan 1991, 

Alexandratos 1995). The gradual growth of world food 

production is slackening because of a decline in demand 

in those countries that can afford food, and insuffi cient 

personal incomes in countries whose people would consume more food, if available (Ingco et al. 1996). 

Advances in Agricultural Technology

Early agricultural advances in developing countries 

were established by transferring technologies and management practices of the developed countries for a few 

agronomic crops with high production potential—the 

green revolution. Several undesirable consequences of 

the green revolution have been identifi ed, particularly 

the implied objective of maximizing yields regardless of 

system stability (Daily et al. 1998). Excluding the technological needs of arid regions is another problem. Regardless, the prevailing technological direction is expected 

to continue over the next 15 years (Alexandratos 1995), 

although the most likely outcome is for the green revolution to become less and less effective (Mann 1997). 

If a real innovation in forage supply happens during 

the projection period for this Assessment, it most conceivably will involve biotechnology. Discoveries in biotechnology have provided numerous breakthroughs for 

industrial development of benefi cial ways to prevent or 

treat illness, make better use of energy sources, and produce more nutritious foods (President’s Council of Advisors on Science and Technology 1992). In agriculture, the 

central emphases for biotechnology during the fi rst half 

of the 21st Century are expected to focus upon food safety, 

gene sequencing and mapping, metabolic studies leading to new uses for plant materials, and animal growth 

and development (U.S. National Science and Technology 

Council, Biotechnology Research Subcommittee 1995).

Biotechnology holds some promise of being able to 

lessen existing biological limitations on agricultural production by improving tolerances to different physical 

stresses (Platais and Collinson 1992). Other problems in 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 59

Maintenance of Productive Capacity CHAPTER 4

American agriculture being resolved with biotechnology 

include biological control of non-indigenous weeds and 

insects, and improving the metabolic effi ciency of domestic herbivores for meat and milk production (Persley 

1990). Some scientists see the most profound consequence 

of biotechnology in future years to be in the fi eld of altering the chemical composition of plants and animals to 

improve their nutritional value for food (Bills and Kung 

1992). Disputes over environmental risks identifi ed with 

genetically-modifi ed food plants may measurably slow 

the application of genetic engineering, and perhaps other 

forms of biotechnology (Ferber 2000).

Biotechnology is also increasingly concentrating upon 

environmental health—studies of the origins, pathways, 

and outcomes of chemical contaminates that may elevate 

risks to human health—rather than the broader subject 

of ecosystem sustainability (Rapport 1998). Gene therapy 

and other new biologies are also part of a larger biotechnological research program in environmental health 

(Rudolph and McIntire 1996).

Unfortunately, there is no way to assess how discoveries in biotechnology will improve rangeland forage production. To benefi t rangeland forage production, research 

and development will have to eventually shift toward 

improving technologies for more marginal areas using 

species other than those with high yield potentials (Hazell 

and Ramasamy 1991). Moreover, until world research priorities shift toward the inclusion of arid and semi-arid 

regions, increases in global forage production because of 

new breakthroughs in technology are not expected to be 

signifi cant. An important exception could be in the abovementioned area of pest control. Even the expanding discipline of biological control poses environmental risks if 

not employed in a deliberate and careful manner, a condition that may limit widespread application of this aspect 

of biotechnology (Louda et al. 1997).

One area that shows promise is the integration of 

new fi ndings in genetics to promote maintenance of the 

genetic variation in forage plant materials necessary for 

adaptation to changing environments. If genetic concepts 

can be broadly integrated into planning for rangeland 

seedings, discussed in the section below, increases in productivity may result in small national benefi ts not presently anticipated (Jones and Johnson 1998).

Application of Existing Technology

Agricultural technology is being called upon to achieve 

goals associated with sustainable land management, 

including decreased soil erosion and improved water 

quality and quantity, both ground- and surface-based 

(Magleby et al. 1995, Committee on Long-Range Soil and 

Water Conservation 1993). Nonetheless, further advances 

in existing technology will have to be profi table if U.S. 

agriculture is continue in its course of economic development. Some researchers foresee limits to developing socalled green technologies because of a lack of markets 

and intrinsic social barriers to adopting new practices 

(Hrubovcak et al. 1999). These same impediments should 

apply to the management of private rangelands for livestock production.

Forage production can be increased by implementing 

existing rangeland restoration practices that modify species composition and/or vegetation structure to improve 

forage production from desirable species. Promoting species that further management objectives has led the Forest 

Service, Bureau of Land Management (BLM) and Natural 

Resources Conservation Service (NRCS) to differentiate 

between potential natural community (PNC) and desired 

plant community (DPC) (USDA Natural Resources Conservation Service 1997):

PNC: The biotic community that would become established on an ecological site if all successional 

sequences were completed without human interference under the present environmental conditions.

DPC: One of several plant community types that may 

occupy an ecological site that meet both the manager’s objective and the minimum quality criteria 

for the soil, water, air, plant, and animal resources. 

Desired plant communities may result from modifi cation 

of vegetation by mechanical means, seeding, chemicals, 

prescribed fi re, biological control, fertilization, or various combinations thereof (Heady and Child 1994). Little 

information exists at a national scale that depicts trends 

and effects of these treatments on forage production.

Mechanical brush clearing has been used to increase 

the forage supply for many years, particularly in areas 

invaded by woodland tree species (Miller et al. 1995). 

In pinyon-juniper stands, herbage production tends to 

follow a negative exponential distribution with increasing overstory canopy, staying fairly low until canopy 

cover approaches zero (Pieper 1983). Seeding and herbicides can be used independently or in conjunction with 

mechanical treatments. The former is expedient where 

terrain, soils, and available precipitation can provide a 

reasonable chance of stand establishment, and native 

forage species are lacking (Plummer et al. 1955). Herbicides have historically been used for brush control (Young 

et al. 1981), but they are now being increasingly applied 

as a component of integrated pest management in controlling invasive plants (Lym et al. 1997).

The annual rate of brush control and seeding on lands 

managed by the BLM has not changed signifi cantly since 

1980, even though the apparent trends seem to be down 

for seeding (fi gure 4.1) and up for brush control (fi gure 

4.2). The median areas seeded and cleared of brush annually on BLM lands during this period have been about 
60 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 4 Maintenance of Productive Capacity

Fig. 4.1—Rangeland managed by USDI Bureau of Land Management seeded to forage species as a range improvement 

practice, 1979–1996 (Public Land Statistics, various years).

200

100

1970 1980 1990

Year

Acres x 103

2000

-100

27,000 acres and 20,000 acres, respectively. Nonstructural range restorations, not counting treatment of noxious weeds, has declined from 35,200 acres during the 

mid-1990’s to 23,800 acres in 1990; this short-term trend 

refl ected decreased funding (USDA Forest Service 1999). 

These statistics are not signifi cant from a national perspective. Additionally, the strategic plans of both the Forest 

Service and BLM contain performance goals emphasizing restoration of riparian areas and high-priority watersheds over lower-priority upland sites. Thus, mechanical 

improvements, seeding, and herbicide applications are 

not anticipated to signifi cantly increase the Nation’s 

forage supply in themselves over the next 50 years.

For rangelands as a whole, it is not possible to project 

the impact of dynamics in the distribution and development of woodlands over the next 50 years. Tausch (1999b) 

has concluded that the next 150 years could actually bring 

about a considerable reduction in the area dominated by 

pinyon-juniper because of large fi res arising from extensive stands with close canopies. Other areas of the United 

States will likely see continued increases in undesirable 

woody species (Archer 1994). 

Some technological advances in rangeland management will be directed towards goals that do not directly 

improve the Nation’s forage supply, for example those 

mitigating impacts on water quality (Binkley and Brown 

1993).

Changes in Rangeland Health

Because the U.S. rangeland health situation is described 

in Chapter 3, this section is limited to a prognosis for 

Fig. 4.2—Rangeland managed by USDI Bureau of Land Management cleared of brush and trees as range or watershed 

improvement practices, 1979–1996 (Public Land Statistics, various years).

80

1970 1980 1990

Year

Acres x 103

2000

60

40

20

0

increased forage production available for consumption by 

wildlife and domestic livestock in response to expected 

changes in rangeland health or condition.

Research has shown that productivity and diversity are 

related to the extent that rangeland has been degraded 

(Reid 1946, Breman and de Wit 1983). Thus, if broad 

advances in range condition can be attained, the supply 

of forage will be increased, at least in mesic ecosystems. 

In arid and semiarid rangelands, however, productivity 

can inexorably decline once degradation passes certain 

thresholds (Milton et al. 1994).

Aside from the condition of private rangeland in the 

South (SO) Assessment Region, the results presented in 

Chapter 3 do not portray many opportunities for signifi -

cant increases in available forage from U.S. grazing lands 

in the near term. Trends are not improving in areas with 

the best capacity for positive change—the mesic South 

and Southeast. Major ecosystems dominating the southwestern part of the Rocky Mountains (RM) Assessment 

Regions are not capable of rapidly recovering to higher 

ecological states, either, because of the imposition of 

thresholds and the slow nature of succession in arid and 

semiarid rangelands (Friedel 1991, Laycock 1991). 

Numerous individual “success stories” have been 

recorded where range forage quality and production have 

been spectacularly advanced by good management practices (Masters et al. 1996, Bradford 1998). However, one 

cannot conclude that (1) these management-unit achievements will be manifested in a greater forage supply 

regionally than is revealed in the trends shown in Chapter 3, or (2) any increased forage production will lead to 

increased livestock stocking levels or cause wildlife populations to expand on a regional scale. 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 61

Maintenance of Productive Capacity CHAPTER 4

Perceived confl icts between grazing and biodiversity, 

risks to threatened and endangered species, and water 

quality have led some environmental organizations to 

employ lawsuits and other mechanisms to limit livestock 

numbers on federal land (Kenworthy 1998). Propositions 

to eliminate livestock grazing from large tracts of semiarid and arid public western rangelands will tend to counter any plans to increase the broad use of added forage 

by livestock (Donahue 1999). These actions are consistent with a scenario analysis by Van Tassell et al. (1999) 

that forecasts a higher likelihood for decreased livestock 

utilization of grazing lands in the RM and Pacifi c Coast 

(PC) Assessment Regions than for outcomes where grazing levels are maintained or even increase. 

Steps to limit livestock grazing on public lands are 

being taken even though ample evidence exists that 

most rangeland landscapes and plant communities can 

tolerate a certain degree of herbivory (Vavra et al. 1994). 

For example, Holechek et al. (1999) have concluded 

that a stocking rate that consumes only 30–35 percent 

of available forage, with some destocking in drought 

years, will maximize profi ts while maintaining range 

condition in the desert Southwest. The above paradox 

was recognized by R.K. Heitschmidt at a recent symposium on the Great Plains when he stated that managed 

grazing is ecologically sustainable, although not always 

economically viable or socially acceptable (Mitchell et 

al.1999b). 

Nationally, harvests of pronghorn, deer, and elk have 

been climbing since the mid-1970’s, although long-term 

projections over the next 50 years do not show a continued increase (Flather et al. 1999). While changes in harvest rates refl ect total population sizes, there is no basis 

to explain why such changes have or are expected to take 

place. Forage supply cannot be singled out as a primary 

causal factor, although it can be important (Caughley 

1970). Thus, the allocation of any increased forage resulting from improved range condition to wildlife is uncertain, but expected (Van Tassell et al. 1999)

Riparian Areas

Perhaps the greatest potential for increased forage 

production in response to improved rangeland health 

within the more xeric RM and PC Assessment Regions 

will come from riparian areas (fi gure 4.3). Three considerations drive this assumption: First, riparian zones can 

account for fi ve or more times the production of available 

forage than uplands on a per unit area basis (Roath and 

Krueger 1982). Second, degraded riparian ecosystems 

can recover to a productive state in relatively few years 

compared to uplands, once proper management practices are implemented (Alford 1993). Finally, although a 

comprehensive appraisal of our Nation’s riparian areas 

has not yet been undertaken, even on public lands (USDI 

Bureau of Land Management 1991), there is evidence 

that some western riparian areas are not in good condition because of improper grazing by cattle. Extensive 

beaver trapping and more recent ill-conceived physical 

modifi cations of stream channels for fl ood control, irrigation, and wetland conversion have exacerbated the situation (Chaney et al. 1990, Elmore and Kauffman 1994).

Regardless of its collective potential for increased primary production, riparian areas cannot be counted on to 

provide greater forage supplies over the next 50 years. On 

public lands, riparian areas often constitute the most critical locations for multiple-use planning because of their 

limited spatial extent; great importance for grazing, wildlife, and biodiversity; high concentration of threatened 

and endangered species; recreational opportunities; and 

rapidly increasing public interest (Platts 1979, Kauffman 

and Krueger 1984, Johnson et al. 1977, Brown et al. 1991, 

Fort 1993). Whether or not any increased forage resulting from widespread changes in riparian health will 

become available for consumption by grazing animals 

will depend in large part upon shifts in public values and 

objectives (Mitchell et al. 1995).

A 1988 General Accounting Offi ce report concluded 

that recovery of western riparian areas will be constrained 

over the foreseeable future by staff reductions in the 

Forest Service and BLM as well as agency institutional 

barriers to making needed changes in the fi eld (U.S. General Accounting Offi ce 1988). The problem of staffi ng 

remains (see chapter 5), but, on the other hand, the Forest 

Service, BLM, NRCS, Fish and Wildlife Service, and other 

agencies have promoted riparian area restoration as a key 

component in the Clean Water Action Plan announced 

by the President in February 1998. Since the focus of the 

Clean Water Action Plan is on restoration and the economic benefi ts of clean water conveyed therein relate primarily to recreation, tourism, and the commercial fi sh 

and shellfi sh industry, one cannot expect to gain a signifi -

cantly increased forage supply from riparian areas over 

the next 50 years.

U.S. Livestock Production

When assessing the productive capacity of forests at 

a national scale, the total growing stock of timber is 

an essential indicator. On rangelands, vegetation in the 

form of forage may be a principal indicator of productive capacity, but livestock numbers can also act as a measure of a productive capacity from a commodity point of 

view.
62 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 4 Maintenance of Productive Capacity

Fig. 4.3—Sandhills-mixed vegetation in eastern Colorado in (a) 1907 and (b) 1949. This rangeland had been heavily grazed for years 

at the time of the fi rst photograph, but was being properly grazed before the time of the second photograph. From McGinnies et al. 

1991.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 63

Maintenance of Productive Capacity CHAPTER 4

Cattle and Sheep Numbers

Joyce (1989) described the U.S. historical trends in 

cattle, sheep, horses, and goats from the mid-1800’s until 

1986. Cattle and sheep numbers were roughly equivalent 

from the time records were fi rst made until the 1880’s, 

the decade marking the end of much of the western 

open range (Mitchell and Hart 1987). From that era, cattle 

continued to increase until the 1970’s; however, sheep 

remained fairly constant until after World War II, when 

they began a slow decline (Joyce 1989). Reasons for this 

decrease included diffi culties in obtaining adequate labor, 

increased costs from predation and for labor, and the need 

for sheep producers to attain a higher net return in order 

to maintain production (Parker and Pope 1983, Shapouri 

1991). The reduction in lamb packing plants may have 

exacerbated the diffi culties facing woolgrowers by reducing competition for available lambs (Stillman et al. 1990).

The U.S. cattle inventory has undergone cycles since 

the 1880’s. A characteristic cattle cycle lasts roughly 10 

years. It can be divided into an expansion stage, where 

cattle numbers increase following high prices, a turnabout stage that comes in response to lowering prices, and 

a reduction stage where cattle numbers decline (fi gure 

4.4). The latest national cycle peaked in 1996 at 103.5 mil140

1979-86 1967-79

1958-67 1949-58

1938-49

1912-28

1928-38

1896-1912

130

120

110

100

90

80

70

60

50

40

0 5 10

Years in cycle

Million head

15 20

Fig. 4.4—United States cattle inventory cycles, 1896 through 

1996. From Hughes (1997).

Fig. 4.5—Number of livestock on farms in the United States, 

1840–1990. (U.S. Department of Commerce, USDA Census of 

Agriculture — various years).

lion head of all cattle and calves and the reduction stage 

shows no sign of ending before 2000 (USDA National 

Agricultural Statistics Service 1999). Like the 1980’s cattle 

cycle, the apex of the present cycle did not increase the 

national herd size, checking any anticipation of the return 

to long-term herd buildups that had occurred throughout 

the Nation’s history prior to 1975. The USDA Economic 

Research Service projects a cyclical low of 97 million head 

in 2001, followed by only a modest increase to 102 million 

head by 2007, indicating a continuation of fairly constant 

cattle numbers from cycle to cycle (Interagency Agricultural Projections Committee 1998).

During the 10 years since the last range assessment 

(Joyce 1989), the 10-year national numbers of cattle, goats, 

and horses have remained fairly constant (fi gure 4.5). 

Horses are now primarily used for various forms of recreation, so their numbers seem to be immune to agricultural 

economic forces and have not declined at all during the 

latter 20th Century. The shift of livestock production from 

the East to the West (all western Assessment Regions plus 

OK and TX) identifi ed by Joyce (1989) has also apparently steadied at a difference of approximately 10 million 

more head in the West (fi gure 4.6). When OK and TX are 

included in the SO Assessment Region, the two eastern 

regions have more cattle; again, there do not appear to be 

signifi cant shifts in cattle numbers between 1986 and 1996 

(fi gure 4.7).

As mentioned earlier, the situation with sheep has been 

different from that of cattle. Between 1986 and 1993, total 

U.S. sheep and lamb numbers remained somewhat constant between 10.1 million and 11.4 million animals. By 

1996, however, the national herd size had dropped to 8.5 

million head. Preliminary data show this total to have 

1840 1860 1880 1900 1920

Year

Source: USDC (various years), Census of Agriculture Note: Only

source of consistent data for all animal types; latest census 1992

1940 1960 1980

120

Horses

Goats

Sheep

Cattle

100

80

Millions 60

40

20

0
64 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 4 Maintenance of Productive Capacity

Fig. 4.6—Number of cattle in the eastern and western United 

States, 1955–1995. Note: The eastern United States includes 

the North and South Assessment Regions except for OK and 

TX, which are included with the western Assessment Regions.

Fig. 4.7—Number of domestic grazing animals in the United 

States, 1986 and 1996, by Assessment Region.

dropped even further, to 7.6 million head, in 1998. Thus, 

during the 10-year period between 1988 and 1998, the U.S. 

sheep industry may have declined by almost one-third 

(USDA National Agricultural Statistics Service 1991, 1999). 

Between 1986 and 1996, the largest percentage decrease 

in breeding sheep was in the PC Assessment Region, 37 

percent. All other Assessment Regions showed a decline 

of about one-fourth for the same period. Overall, the 

number of breeding sheep declined from 8.5 million in 

1986 to 6.2 million in 1996, a 27 percent drop.

Distribution of Cattle Operations and 

Cattle by Herd Size

One of the factors affecting dynamics of the U.S. cattle 

herd is the distribution of the size of livestock operations. 

Economies of size stipulate that long-term net revenues 

on a per-head basis increase with herd size. A 100-cow 

herd does not provide suffi cient cash fl ow or profi t to support a family operation (Godfrey and Pope 1990). According to Harlan Hughes, Extension Livestock Economist, 

North Dakota University, Fargo (personal communication), family cattle ranches receive an average of approximately $100 per cow.

Lack of management power has the potential to undermine the long-term economic competitiveness of midsized farms and ranches. Management power comes from 

using ranch operational data on land, livestock, labor, and 

capital to make management decisions. However, recent 

treaties and losses of commodity support programs are 

placing more importance on the entrepreneurial nature of 

agriculture. This, along with the exponentially increasing 

availability of information on the Internet, is making agriculture more competitive. There is some indication that 

mid-sized farmers and ranchers are, as a group, too busy 

to assemble and analyze operational data or to access 

other sources of information in order to compete with 

larger operations (Hughes 1999).

Little is presently known about how the distribution 

of livestock operations and herd size are related to the 

productive capacity of U.S. rangelands, either public or 

private. The subject entails an interesting area of needed 

research.

The vast majority of U.S. cattle operations are too small 

to sustain themselves economically without other sources 

of income such as farming or outside jobs. In 1993, only 19 

percent of all cattle owners had herds larger than 100 cows. 

Only 2 percent of all cattle are raised by ranchers with commercial herd sizes of 500 cows or more (table 4.1). 

Within Assessment Regions, the distribution of different-sized cattle operations varied greatly in 1993. Nearly 

40 percent of operations in the RM Assessment Region 

had more than 100 cows, compared to less than 20 percent 

in the each of the other Assessment Regions (table 4.1).

Grazing Use on Federal Lands

Livestock grazing on BLM and National Forest System 

(NFS) lands has been stable over the past 30–40 years. On 

NFS lands, the number of animal unit months (AUM—

the biomass of forage consumed by a 1000-lb. cow with a 

70

60

50

40

30

20

10

0

1955 1960 1965 1970 1975

Year

# of animals (millions)

Eastern

Note: East: NO and SO regions except OK and TX; West: all other regions

and OK and TX. Data for 1996 is preliminary. Source: USDA Agricultural

Statistics: 1956-1996

Western

1980 1985 1990 1995
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 65

Maintenance of Productive Capacity CHAPTER 4

Region/State 1–49 50–99 100–499 500–999 1000+

Pacifi c Assessment Region

 CA 17,300 1,900 3,500 1,200 1,100

 OR 18,400 1,800 2,200 400 200

 WA 17,100 1,300 2,200 250 150

 Total 52,800 5,000 7,900 1,850 1,450

 Percent 77 7 11 3 2

Rocky Mountain Assessment Region

 AZ 2,700 500 1,000 180 190

 CO 5,700 2,100 4,100 700 400

 ID 7,800 1,800 2,800 380 220

 KS 17,800 8,400 10,300 920 500

 MT 4,500 2,200 5,200 900 300

 ND 4,500 3,900 6,100 430 70

 NE 10,500 6,400 10,000 1,200 900

 NM 4,900 1,200 2,100 450 350

 NV unk unk unk unk unk

 SD 6,300 4,200 9,700 1,300 500

 UT 4,400 1,100 1,900 260 140

 WY 2,600 700 1,800 500 300

 Total 71,700 32,500 55,000 7,220 3,870

 Percent 42 19 33 4 2

Southern Assessment Region

 AL 24,000 4,800 3,900 240 60

 AR 21,500 6,000 4,300 170 30

 FL 14,600 2,400 2,300 400 300

 GA 21,000 4,200 3,600 150 50

 KY 37,000 9,400 6,400 180 40

 LA 14,100 2,800 2,400 160 40

 MS 21,000 4,200 3,500 260 40

 NC unk unk unk unk unk

 OK 39,000 10,900 10,700 900 500

 SC unk unk unk unk unk

Table 4.1—Distribution of U.S. farms and ranches with cattle, by herd size and Assessment Region, 1993. From USDA National Agricultural Statistics Service 1994.

Region/State 1–49 50–99 100–499 500–999 1000+

Southern Assessment Region (cont.)

 TN 52,000 8,400 5,400 150 50

 TX 100,000 21,000 22,500 2,100 1,500

 VA 20,500 4,800 4,400 250 40

 Total 364,700 79,800 69,400 4,960 2,650

 Percent 70 15 13 1 1

Northern Assessment Region

 CT unk unk unk unk unk

 DE unk unk unk unk unk

 IA unk unk unk unk unk

 IL 21,000 5,400 4,400 190 60

 IN 24,000 3,500 2,400 80 20

 MA unk unk unk unk unk

 MD 5,200 800 780 10 10

 ME unk unk unk unk unk

 MI 12,800 2,900 3,000 250 50

 MN 17,600 11,100 9,000 200 100

 MO 47,000 15,000 12,400 510 90

 NH unk unk unk unk unk

 NJ unk unk unk unk unk

 NY 11,000 4,800 5,000 150 50

 OH 32,600 4,700 3,500 170 30

 PA 21,000 7,100 4,800 80 20

 RI unk unk unk unk unk

 VT 1,500 1,300 1,200 50 10

 WI 21,500 14,800 14,400 270 30

 WV unk unk unk unk unk

 Total 215,200 70,600 60,100 1,960 470

 Percent 62 20 17 1 0

 All “unk”

 states 34,900 3,900 3,900 450 120

 Total, 

 all states 739,300 191,800 196,300 16,440 8,560

suckling calf in one month, or about 780 lb. dry weight) 

has varied within 10 percent of 10 million AUM’s since 

1960 (fi gure 4.8). Grazing use on NFS lands has also been 

steady by Assessment Region with the exception of the 

SO Assessment Region (fi gure 4.9 through fi gure 4.14). 

Cattle grazing on NFS lands in the South has been declining constantly since 1970 (fi gure 4.13), but its contribution 

to overall livestock grazing in the region has always been 

small.

Livestock grazing use of BLM lands has also remained 

nearly constant at around 10 million AUM’s over the past 

20 years (fi gure 4.15). Declines in the Pacifi c Northwest 

and California did not involve enough AUM’s to affect 

the national trend (fi gure 4.16, fi gure 4.17). Total livestock 

grazing use on BLM lands in the Intermountain, Rocky 

Mountain, and Southwestern regions have not notably 

declined since 1980 (fi gure 4.18, fi gure 4.19).

Another way of assessing the extent of livestock grazing 

on U.S. federal rangelands is to examine trends in non-use. 

In the last rangeland assessment document, Joyce (1989) 

defi ned non-use of cattle and sheep on NFS lands as 

1 - (authorized AUM’s/permitted AUM’s)

where authorized use was the sum of all of paid permits 

contained in annual authorizations and permitted use 
66 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 4 Maintenance of Productive Capacity

USDA, Forest Service (1978-1995)

12

Year

AUMs (millions)

10

8

6

4

2

0

1952 1956 1960

Cattle and horses

Sheep and goats

Total permitted use

1964 1968 1972 1976 1980 1984 1988 19921995

Fig. 4.8—Livestock grazing use of National Forest System lands, 

1953–1995.

800

AUMs (thousands) 600

400

200

0

USDA, Forest Service (1978-1995)

Year

1952 1956 1960

Cattle and horses

Sheep and goats

Total permitted use

1964 1968 1972 1976 1980 1984 1988 19921995

Fig. 4.9—Livestock grazing use of National Forest System lands, 

Pacifi c Northwest Region, 1953–1995.

700

600

AUMs (thousands) 500

400

300

200

100

0

USDA, Forest Service (1978-1995)

Year

1952 1956 1960

Cattle and horses

Sheep and goats

Total permitted use

1964 1968 1972 1976 1980 1984 1988 19921995

Fig. 4.10—Livestock grazing use of National Forest System 

lands, Pacifi c Southwest Region (California), 1953–1995.

7

6

5

4

3

2

1

0

USDA, Forest Service (1978-1995)

Year

AUMs (millions)

1952 1956 1960

Cattle and horses

Sheep and goats

Total permitted use

1964 1968 1972 1976 1980 1984 1988 19921995

Fig. 4.11—Livestock grazing use of National Forest System 

lands, Northern Region, 1953–1995.

USDA, Forest Service (1978-1995)

Year

AUMs (thousands)

1952

3000

0

500

1000

1500

2000

2500

1956 1960

Cattle and horses

Sheep and goats

Total permitted use

1964 1968 1972 1976 1980 1984 1988 19921995

Fig. 4.12—Livestock grazing use of National Forest System 

lands, Southwestern Region, 1953–1995.

400

AUMs (thousands)

Year

1953

Estimated C & H

Cattle & horses

Source: USDA Forest Service (1954-1995)

1957 1961 1965 1969 1973 1977 1981 1985 1989 1993

300

200

100

0

Fig. 4.13—Livestock grazing use of National Forest System 

lands, South Assessment Region, 1953–1995.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 67

Maintenance of Productive Capacity CHAPTER 4

200

150

100

50

0

AUMs (thousands)

Year

1953

Estimated C & H

Cattle & horses

Source: USDA Forest Service, Grazing Statistical Summary: 1954-

1995

1957 1961 1965 1969 1973 1977 1981 1985 1989 1993

Fig. 4.14—Livestock grazing use of National Forest System 

lands, North Assessment Region, 1953–1995.

14

Year

AUMs (millions)

12

10

8

6

4

Total

USDI BLM Public Land Statistics: (1970-1994)

1969 1971 1973 1993 1975 1977 1979 1981 19831985 1987 1989 1991

Section 3

Section 15

2

0

Fig. 4.15—Livestock grazing use of Bureau of Land Management lands, 1969–1993. All public lands within the boundaries 

of grazing districts are managed under Section 3 of the Taylor 

Grazing Act of 1934. These areas contain large blocks of public 

land. Lands outside the boundaries of grazing districts are managed under Section 15 of the Act. These are mostly small, isolated tracts of land.

1969197019711972197319741975197619771978197919801981198219831984198519861987198819891990199119921993

1200

Year

AUMs (thousands)

1000

800

600

400

200

0

Sheep and goats, section 3

USDI BLM Public Land Statistics: (1970-1994)

Total section 3

Cattle and horses, section 3

Total section 3 and 15

Fig. 4.16—Livestock grazing use of Bureau of Land Management lands, Pacifi c Northwest states, 1969–1993.

500

Year

AUMs (thousands)

0

100

200

300

400

1969 1971

USDI Public Land Statistics: (1970-1994)

1973 1993 1975 1977 1979 1981 1983 1985 1987 1989 1991

Sheep and goats, section 3

Total section 3

Cattle and horses, section 3

Total section 3 and 15

Fig. 4.17—Livestock grazing use of Bureau of Land Management lands, California, 1969–1993.

was the sum of all animals permitted to graze, both 

expressed in AUM’s (FSM 2231.41). Authorized use can 

differ from permitted use for a number of reasons known 

before the grazing season commences that affect the available forage supply, and is usually less than permitted 

use. Examples include a drought the preceding year and 

restrictions resulting from logging or reforestation. 

Increasing non-use, as described by Joyce (1989), probably does not refl ect a general economic decline in the 

agriculture sector. Such a decline would more likely be 

expressed in terms of falling livestock numbers actually 

permitted to graze on NFS lands. There are provisions 

to adjust permitted livestock numbers to ensure proper 

use of the forage resource and/or to comply with forest 

management plans, laws, regulations, and policy (FSM 

2231.6).

Joyce’s (1989) defi nition of non-use differs from that 

depicted under FSH 2231.7 which allows an individual 

permittee or the Forest Service to temporarily withhold 

grazing on an allotment for permittee convenience, 

resource protection, or range research purposes. For this 

Assessment, I have continued portraying non-use following Joyce’s defi nition.

In the last rangeland assessment document, Joyce 

(1989) reported that non-use of cattle allotments was 

increasing even though permitted use had remained constant. Percentage non-use of sheep allotments exceeded 

that for cattle, but had remained reasonably constant 
68 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 4 Maintenance of Productive Capacity

3000

AUMs (thousands)2500

0

500

1000

1500

2000

Year

1969 1971

USDI Public Land Statistics: (1970-1994)

1973 1993 1975 1977 1979 1981 1983 1985 1987 1989 1991

Sheep and goats, section 3

Total section 3

Cattle and horses, section 3

Total section 3 and 15

Fig. 4.19—Livestock grazing use of Bureau of Land Management lands, Arizona and New Mexico, 1969–1993.

10AUMs (millions)

8

6

4

2

0

Year

1969 1971

USDI Public Land Statistics: (1970-1994)

1973 1993 1975 1977 1979 1981 1983 1985 1987 1989 1991

Sheep and goats, section 3

Total section 3

Cattle and horses, section 3

Total section 3 and 15

Fig. 4.18—Livestock grazing use of Bureau of Land Management lands, Intermountain and Rocky Mountain states, 

1969–1993.

during the same period. After adding annual statistics for 

10 more years (1987–96), it is becoming evident that the 

proportion of authorized to permitted cattle is not showing long-term increases but has remained variably steady 

between 10 and 15 percent since the early 1980’s. The 

proportion was higher in 1988, 1990, and 1991 for some 

reason. Sheep non-use has ranged between 19 and 25 percent during the past 20 years, and also shows no longterm trend (fi gure 4.20).

Consumption of Red Meat

Domestic Consumption

Demand for red meat may act as a useful indicator 

for grazing land productive capacity because it has a 

direct bearing on national livestock numbers. Total per 

capita consumption of beef/veal, pork, poultry, fi sh, and 

lamb combined has very slowly increased since the early 

1980’s. The same trend noted by Joyce (1989) in the last 

assessment has continued. If this trend continues, Americans will soon be eating more than 200 lb. of meat 

per year. The increase in per capita meat consumption 

is due to rising use of poultry in U.S. diets. Statistics 

from USDA National Agricultural Statistics Service (1999) 

show annual per capita poultry consumption going from 

32.9 lb. in 1975 to 65.8 lb. in 1998 (fi gure 4.21). 

Percent non-use

30 Cattle

Source: USDA Forest Service, Grazing Statistical Summary: 1978-

1995 Note -- Non-use = [ 1 - (actually grazed/paid authorized use)

Sheep

1977 1994 1987 1989 1990 1992

Year

1979 1981 1983 1985 0

5

10

15

20

25

Fig. 4.20—Non-use of cattle and sheep permitted use on 

National Forest System Lands. Note: Non-use is defi ned as the 

proportion of permitted livestock use, expressed in AUM’s, not 

authorized by annual operating plans: 1. – (authorized AUM’s/

permitted AUM’s). See Joyce (1989).

In 1995 and 1996, the National Agricultural Statistics 

Service reported average annual per capita consumption 

of beef and veal in boneless, trimmed meat equivalents as 

64 lb., the same as it was in 1990 (USDA National Agricultural Statistics Service 1999). Thus, beef/veal consumption continues to be level.

With individual red meat consumption at a constant 

level, increases in domestic consumption will primarily 

be a function of population increases. Even these increases 

are projected to be fairly small over the next 20 years, particularly in comparison to expected growth in meat consumption within developing countries (table 4.2).
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 69

Maintenance of Productive Capacity CHAPTER 4

Fig. 4.21—Per capita consumption of beef and veal, pork, lamb 

and poultry in the United States, 1975 to 1991. Note: Total meat 

consumption includes veal, lamb, and mutton. (Frazão 1999).

Table 4.2—Projected changes (percent) in total meat consumption in the developing and developed countries, 1990-2020.

Product Developed Countries Developing Countries

Beef, other 

 ruminant meat 11 to 14 101 to 170

Pork 12 to 16 131 to 225

Poultry 30 to 31 126 to 211

From Sere and Steinfeld (1996)

Meat Exports and Imports

In 1970, meat imports exceeded exports by more than 

an order of magnitude. Beef imports added to 813,000 

metric tons while beef exports were only 46,000 metric 

tons. Between then and the time of the last Assessment 

(Joyce 1989), meat imports increased slightly, but exports 

expanded more than fi ve-fold. Beef imports and exports 

were 1.03 million metric tons and 274,000 metric tons, 

respectively (USDA Economic Research Service 1989).

According to USDA-ERS (Interagency Agricultural Projections Committee 1998), the short-term trend of expanding beef exports will be delayed until weak demand in the 

Pacifi c Rim recovers and the U.S. cattle inventory builds to 

higher levels. How the world beef trade will adjust to the 

more open markets created by GATT is far from certain. 

Long-term growth in beef demand in the Pacifi c Rim may 

be slower than previously anticipated, however (Interagency Agricultural Projections Committee 1998). Regardless, the U.S. continues to be the principal source of highquality fed beef for export, and the Pacifi c Rim will provide the largest market for these meats.

Conclusions

The productive capacity of U.S. rangelands will not 

likely change signifi cantly in the near future. The expected 

slow decline in the grazing land base may be offset, in 

part, by equally slow increases in rangeland health and 

advances in grazing technology. Projected slowly rising 

consumption of red meat should not create extensive 

new demands for forage. For that and other reasons, 

lands in the Conservation Reserve Program, described 

in chapter 2, are not expected to have even a moderate 

effect on livestock numbers. They have been shown to 

have a positive infl uence on some wildlife species at 

the regional level, however, including the provision for 

feeding cover. A proliferation of non-indigenous weeds, 

explained in chapter 3, Rangeland Health, could feasibly impact the productive capacity of rangeland, regionally. If demands for forage ever exceed supply, however, 

market forces should prompt shifts in land use from agriculture to grazing land, such as described in chapter 2, 

Extent of Rangelands.

Since there is no reason to expect signifi cant increases 

in the rangeland base, advances in technology affecting 

productivity of rangeland forage species, or restoration of 

rangeland health, we must conclude that the supply of 

forage in the United States is not likely to change signifi -

cantly over the next few decades. The country’s productive capacity should remain adequate to promote sustainable management of U.S. rangelands, however.

Beef

Pork

Poultry

Fish

Total

200

150

100

50

Year

Pounds

0

1970197319761979198219851988199119941997

USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 71

Criterion 7 of the Montreal Process pertains to a country’s overall policy framework that can facilitate the conservation and sustainable management of forests. Because 

20 of the 67 total Montreal Process indicators are under 

Criterion 7, they have been clustered into fi ve sub-criteria. 

Applied to rangelands, these sub-criteria are: The extent 

to which the (1) legal framework, (2) institutional framework, and (3) economic framework support the conservation and sustainable management of rangelands; (4) the 

capacity to measure and monitor changes in the conservation and sustainable management of rangelands; 

and (5) the capacity to conduct and apply research and 

development aimed at improving rangeland management delivery of rangeland-derived goods and services 

(USDA Forest Service 1997).

The legal framework was succinctly discussed in Chapter 1. In the latter half of the 20th Century, numerous 

laws promoting various conservation practices, including 

public involvement in federal land management planning, have been written into U.S. law (table 1.3). Conservation and stewardship provisions included in various 

farm bills have added to the legal framework for sustainable management.

The institutional framework for sustainable rangeland 

management at a national scale focuses, among other things, 

upon providing for public involvement activities, undertaking periodic planning, assessment and policy reviews, and 

developing and maintaining human resource skills across 

relevant disciplines. The purpose here is to address this last 

indicator, maintaining a critical mass of people with adequate technical skills to properly manage rangelands and to 

conduct needed research and development.

Rangeland Science Education

The education of students in rangeland management 

and related disciplines at the undergraduate level has 

undergone a transformation since the 1980’s, principally 

in response to two factors: (1) Advances in ecology and 

management applications and (2) changing employment 

opportunities for graduates. 

For the 40-year period ending in the late 1980’s, most 

range management students took courses emphasizing a 

triad of plant, soil, and animal sciences. The principal job 

opportunity for those with an undergraduate degree was 

as a range conservationist with the federal government. 

Chapter 5: Institutional Framework for 

Rangeland Conservation and Sustainable Management

As stipulated by law, public rangelands were (and are) 

managed under a multiple-use, sustained-yield concept 

for grazing livestock, wildlife habitat, recreation, water, 

and timber production. Doctoral students often found 

employment with teaching and research universities after 

graduation. Following far behind were careers managing 

ranches and working for consulting companies. 

In the 1990’s, both the job market and undergraduate 

curriculum began to change. Working for regulating agencies, environmental organizations, and companies specializing in rangeland restoration became a much more 

promising career choice (Personal communication, Dr. R. 

Dennis Child, Colorado State University, Fort Collins). 

Employment as a rangeland conservationist with federal 

land management agencies started to involve new skills. 

The planning process has taken on an increasingly important role in rangeland management. It now must provide 

for alternative actions, be developed on a multi-resource 

basis, and include public involvement. Consequently, curricula have also diversifi ed and now incorporate such subjects as ecosystem/sustainable management, landscape 

ecology, biodiversity, restoration ecology, and rangeland 

planning (Kothmann 2000).

Department names have changed to refl ect the new 

science of rangelands (Kothmann 2000). The four largest 

Table 5.1—Names of university departments offering a range 

management degree in the United States. Number in parentheses indicates more than one university with the same name. 

From Kothmann (2000).

Offering Ph.D. Degree Not offering Ph.D. Degree 

Rangeland Resources (2)1

 Agriculture

Rangeland Ecology and Agribusiness, Agronomy, 

Management1 Horticulture and Range 

 Management

Rangeland Ecosystem Science1

Agronomy (2) Animal and Range 

 Sciences (2)

Animal and Range Sciences (2) Animal and Wildlife Sciences

Botany and Range Natural Resource 

 Management

Environmental Sciences, Rangeland Resources and 

Policy & Management Wildland Soils

Plant and Soil Sciences

1

 Four largest departments
72 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 5 Institutional Framework for Rangeland Conversation and Sustainable Management

university departments all have the word “rangeland”

instead of “range,” in them (Table 5.1). In addition, a 

broad range of concentration areas are offered within 

undergraduate degree programs. Range and Forest Management, Rangeland Ecology, and Restoration Ecology 

can now be found in the Colorado State University General Catalog, for example.

Trends in student numbers have been mixed during 

the 1990’s. Annual enrollments at the B.S., M.S., and 

Ph.D. levels collectively increased about 25 to 30 percent 

between 1991 and 1996. Since then, enrollments have 

been dropping (fi gure 5.1). Although more undergraduates were enrolled in rangeland-related curricula at the 

end of the last decade than at the beginning, nearly all 

of the increase can be attributed to smaller universities 

Fig. 5.1—Number of undergraduate (A) and graduate (B) range science majors, 1991, 

1996, and 1999 (from Kothmann 2000).

in the Southern Assessment Region (Texas) that stress 

teaching over research. Numbers of students training 

to be researchers, particularly Ph.D. candidates, showed 

a downward trend during the latter 1990’s (Kothmann 

2000), but no long-term prognoses are possible from these 

data, alone. It is likely that student numbers are holding 

somewhat constant because of the more diverse employment opportunities mentioned above.

The number of rangeland science faculty members, 

expressed as full-time equivalents (FTE), has remained 

exceptionally constant through the 1990’s. Teaching positions have held within a narrow range of 58 to 62 FTE’s 

between 1991 and 1999, and positions devoted to research 

have varied between 59 and 69 FTE’s with no apparent 

trend. During the same time period, faculty allocations 
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 73

Institutional Framework for Rangeland Conversation and Sustainable Management CHAPTER 5

for rangeland extension actually increased from 34 to 44 

FTE’s (Kothmann 2000). 

There is no information on a possible “aging” effect 

upon the population size of university faculties of rangeland science. However, if a substantial proportion of faculties are approaching retirement, the outlook for continued stability is not favorable unless university administrators replace retiring faculty members with others in 

disciplines related to rangeland science or management. 

Informal discussions with heads of rangeland science 

departments indicates that, at best, only a fraction of retirees will be replaced during the foreseeable future. An 

emerging trend within natural resource academia of splitting FTE’s into multiple departments (replacing a retiring professor with someone who is part-time in another 

department) may moderate any net losses of rangeland 

science faculty.

Trends in Persons Employed in 

Rangeland Management

Employment trends of rangeland conservationists in the 

three principal Federal land management agencies—Forest 

Service (FS), Bureau of Land Management (BLM), and NatFig. 5.2—Trends in the number of permanently-employed rangeland conservationists 

working for the USDA Forest Service, USDA Natural Resource Conservation Service, 

and USDI Bureau of Land Management, 1989–1999. From unpublished data.

ural Resources Conservation Service (NRCS)—depict two 

different patterns, one holding steady and one a constant 

decline (fi gure 5.2). The number of rangeland conservationists in the FS dropped by 21 percent between September 

1992 and May 1999. Losses were not evenly split across 

FS regions. The Intermountain Region lost 48 positions 

(40 percent), while the Eastern Region gained one position 

(100%). All FS regions have identifi ed current and future 

staffi ng shortages of rangeland conservationists (Unpublished report, National Academy of Public Administration, 

Washington DC). During a roughly comparable time, 1990 

to 1997, the BLM lost 137 rangeland conservationist positions, a decrease of 28 percent (Unpublished data, USDI 

Bureau of Land Management, Washington DC).

One reason for declining numbers of rangeland conservationists within the FS is the recent tendency to classify 

positions so that individuals can supervise or be responsible for two or more different specialties. This policy has dramatically expanded the number of general biologist positions within the FS because a general biologist can supervise foresters, wildlife biologists, soil scientists, and rangeland conservationists (Unpublished report, National Academy of Public Administration, Washington DC). Effects of 

classifi cation have impacted the number of forester positions much more than rangeland conservationist positions. 

An expansion in the number jobs performed by each 

forest staff member, following agency downsizing, has 

resulted in an erosion of career ladders in several natural 

resource management disciplines, including rangeland 
74 USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000.

CHAPTER 5 Institutional Framework for Rangeland Conversation and Sustainable Management

conservation. Slowing the rate of advancement has been 

seen to also adversely affect the number of positions fi lled 

by individuals in the rangeland conservationist job series 

(USDA Forest Service, Range Management Staff 1990).

Unlike the FS and BLM, the NRCS has maintained a 

nearly constant workforce of rangeland conservationists 

throughout the 1990’s (fi gure 5.2). There are several possible interrelated reasons for such a disparity. The NRCS 

mission has broad support from state and local organizations such as the National Association of Conservation 

Districts and the Grazing Lands Forum (personal communication, Mr. Dennis Thompson, National Rangeland Conservationist, NRCS). It is feasible that the workload associated with conservation programs in recent Farm Bills has 

been deemed important enough by policymakers to provide expanding budgets for rangeland conservation.

Within the Federal land management agencies, reduced 

hiring has contributed to an increased workforce average 

age. Between September 1992 and May 1999, the average 

age of FS permanent employees jumped by three years, 

from 42.6 to 45.6 years. The number of rangeland conservationists eligible for retirement will rise from 4 percent of the permanent staff in 1999 to 19 percent in 2004 

if present hiring and retention trends continue (Unpublished report, National Academy of Public Administration, Washington DC). An aging workforce adds uncertainty to any outlook of how adequately our Nation will 

maintain a critical mass of people with needed technical 

skills to properly manage rangelands.

The loss of people with adequate resource skills in 

rangeland conservation has, in part, induced the Society 

for Range Management to create a certifi cation process 

for rangeland managers. The Society was concerned that 

people planning and implementing management practices on rangelands increasingly lack basic qualifi cations 

needed to conduct professional work. According to procedures put forth by the Society for Range Management, 

certifi ed professionals should have training and experience in the areas of vegetation and animal management, planning and policy, measurement and assessment, and communications (see: <http://www.srm.org/

procedures.html>). 

Work in research and development is an important 

component of any technical discipline, including natural resource management. In the United States, the preponderance of rangeland-related research is conducted 

by universities and their associated state experiment 

stations, FS research stations, and USDA Agricultural 

Research Service. Non-governmental organizations, such 

as The Nature Conservancy, and other state natural 

resource-related organizations also carry out some range 

research. University professors are responsible for nearly 

all research conducted under the auspices of universities, 

and information about their numbers were discussed 

earlier. 

In the FS, a signifi cant shift has occurred within the 

biological sciences—a shift away from research foresters 

and rangeland scientists and towards ecology and wildlife biology (Unpublished report, National Academy of 

Public Administration, Washington DC). Between 1985 

and 1999, the number of rangeland scientists decreased 

from 3.3 percent to 1.0 percent of the agency’s research and 

development workforce. Many of the remaining rangeland scientists are approaching retirement age (personal 

communication, Craig Whittekiend, Society for Range 

Management, Denver, CO). Thus, given the redirection 

of FS R&D resources since 1985, it is not implausible to 

expect future rangeland research to focus upon hypotheses related to species, community, and ecosystem sustainability. This work will necessarily be undertaken by 

scientists with training, skills, and interests in disciplines 

represented by the existing FS R&D workforce.

To conclude, new approaches are needed to assess how 

well the United States promotes programs that maintain 

human resource skills across relevant disciplines supporting the sustainable management of rangelands. They 

must be able to capture the degree of professional rangeland management, along with support for rangeland 

research, at a time when career paths are not clearly 

defi ned, science is creating previously unidentifi ed disciplines related to monitoring and assessments, and ideas 

about what constitutes sustainable management is becoming more complex, refl ecting the diverse values corresponding with our American society.

An understanding of other social, economic, and political indicators, as expressed in Criteria 6 and 7 of the 

Montreal Process, will also assist future national assessments of U.S. rangelands.
USDA Forest Service Gen. Tech. Rep. RMRS–GTR–68. 2000. 75

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GENERAL TECHNICAL REPORT RMRS-GTR-68

DECEMBER 2000

UNITED STATES DEPARTMENT OF AGRICULTURE

FOREST SERVICE

ROCKY MOUNTAIN RESEARCH STATION