U.S. Department of Agriculture

Interim Update of the 2000 Renewable Resources 

Planning Act Assessment

Forest Service

Interim Update of the 2000 Renewable Resources 

Planning Act Assessment
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, 

national origin, age, disability, and where applicable, sex, marital 

status, familial status, parental status, religion, sexual orientation, 

genetic information, political beliefs, reprisal, or because all or 

part of an individual’s income is derived from any public assistance 

program. (Not all prohibited bases apply to all programs.) Persons 

with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) 

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

and TDD). To file a complaint of discrimination, write USDA, 

Director, Office of Civil Rights, 1400 Independence Avenue, S.W., 

Washington, D.C. 20250-9410, or call (800) 795-3272 (voice) or 

(202) 720-6382 (TDD). USDA is an equal opportunity provider 

and employer.
Interim Update of 

the 2000 Renewable 

Resources Planning 

Act Assessment

United States 

Department of 

Agriculture

Forest Service

FS-874

April 2007

Interim Update of the 2000 RPA Assessment

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

Organization of the Document................................................3

Overview...................................................................................5

Concepts of Sustainable Development and Sustainable 

Forest Management.............................................................9

Social and Economic Context for the Interim Update 

of the 2000 RPA Assessment.............................................11

World Context......................................................................11

. . Box 1—Globalization, consolidation, and structural

change in the U.S. forest sector..........................12

. . Box 2—Plantations..........................................................13

. . Box 3—Trade and the environment.................................14

U.S. Context ........................................................................15

. . Box 4—Amenity migration..............................................16

. . Land Use and Cover in the United States .......................18

. . Box 5—Values change over time.....................................19

. . Forest land........................................................................19

. . Rangeland ........................................................................20

. . Agricultural lands.............................................................21

. . Wetlands...........................................................................21

. . Urban lands......................................................................22

. . Box 6—More people on the forested landscape..............23

. . Box 7—Measures of stress on ecosystems......................24

Summary..............................................................................25

Legal, Institutional, and Economic Framework 

for Forest and Rangeland Conservation and 

Sustainable Management..................................................27

Ownership of Forest and Rangelands..................................27

The Privately Owned Forest and Rangeland Estate ............28

The Publicly Owned Forest and Rangeland Estate .............29

Management of and Access to Inland Water ......................29

Management of and Access to Minerals..............................30

Economic Institutions .........................................................30

. . Markets.............................................................................30

. . Incentives.........................................................................31

. . Box 8—What are ecosystem services?............................32

. . Box 9—What are ecosystem services worth?..................32

Research Institutions............................................................33

Availability and Extent of Data for Measuring 

Indicators of Sustainable Resource Management............33

Minerals............................................................................33

. . Water................................................................................33

. . Rangelands.......................................................................33

. . Forests..............................................................................34

. . Localizing information from higher scale data................38

Summary..............................................................................41

Conservation of Biological Diversity....................................43

Historical Trends in Forest Land Cover...............................43

Area of Timber Land by Forest Type .................................43

Extent of Area by Forest Type and Age Class or

Successional Stage...........................................................44

Extent of Areas by Forest Type in Protected Area 

Categories as Defined by IUCN.......................................45

The Fragmentation of Forests..............................................46

Number of Forest-Dependent Species.................................47

The Status of Threatened and Endangered Species ............49

Number of Forest-Dependent Species That Occupy 

a Small Portion of Their Former Range...........................52

Population Trends in Recreationally Harvested 

Wildlife Species...............................................................52

Rangeland Area ...................................................................54

. . Box 10—Impact of roads on fragmentation.....................56

. . Box 11—Housing change and relative species 

richness of forest birds......................................57

. . Box 12—Conservation easements on private lands.........57

Box 13—Decline in aspen and other early successional

species in the West, Lake States, and 

Northeast...........................................................58

Box 14—Exotic plant richness as an indicator of

ecosystem health...............................................59

Summary..............................................................................60

Maintenance of Productive Capacity of Forest 

Ecosystems..........................................................................61

Forest Products.....................................................................61

. . Area of forest land and net area of forest land available 

for timber production....................................................61

Contents
ii Interim Update of the 2000 RPA Assessment

. . Growing stock available for timber production................61

. . Area and growing stock of plantations.............................62

. . Annual removal of wood products compared to the 

volume determined to be sustainable............................62

. . Annual removal of nontimber forest products 

compared to the level determined to be sustainable.....63

. . Box 15—Certification......................................................64

. . Box 16—Expectations for future timberland area,

forest management types, and private 

inventories.........................................................64

Rangeland Products..............................................................65

. . Number of cattle and sheep..............................................65

. . Grazing use of Federal rangelands...................................65

. . Box 17—Characteristics of private rangeland associated 

with public land grazing leases.........................66

Summary..............................................................................67

Maintenance of Forest and Rangeland Ecosystem 

Health and Vitality.............................................................69

Climate Change....................................................................69

. . Ecosystem impacts...........................................................70

. . Box 18—Sea-level rise.....................................................71

. . Socioeconomic impacts....................................................72

Forest Health and Vitality....................................................72

. . Air pollution.....................................................................72

. . Mortality...........................................................................73

. . Box 19—Bringing climate into natural resource

management......................................................74

. . Area of forest affected by insects and diseases................75

Invasive Plants and Animals................................................75

. . Wildfire.............................................................................76

. . Forest condition class.......................................................76

. . Wildlife.............................................................................76

Rangeland Health and Vitality.............................................76

Summary..............................................................................77

Conservation and Maintenance of Soil and Water 

Resources............................................................................79

Condition of Forest Soil.......................................................79

Soil Organic Matter and Other Soil Chemical Properties....79

Condition of Water Flowing From Forest Land..................80

Summary..............................................................................81

Maintenance of Forest Contributions to Global Carbon 

Cycles..................................................................................83

Carbon Retained in Forests and Forest Products.................83

Carbon Emissions Avoided With Production and Use of

Wood Products.................................................................84

Summary..............................................................................85

Maintenance and Enhancement of Long-Term Multiple 

Socioeconomic Benefits To Meet the Needs of Societies...87

Timber..................................................................................87

. . Production and consumption............................................87

. . . Softwood harvest..........................................................87

. . . Hardwood harvest.........................................................89

. . . Prices............................................................................89

. . Employment.....................................................................90

. . Alternative futures for timber and related markets..........91

. . Box 20—Timber processing capacity for various 

products in the West........................................92

Water....................................................................................93

. . Supply...............................................................................93

. . Withdrawals.....................................................................94

. . Possible future trends.......................................................94

Minerals...............................................................................95

. . Production and consumption............................................95

. . Investment........................................................................95

. . Employment.....................................................................95

Outdoor Recreation..............................................................95

. . Participation.....................................................................96

. . Trends since 1960.............................................................96

. . Trends in the past 20+ years.............................................96

. . Trends since 1995.............................................................99

. . Implications of participation rates..................................100

. . Possible future trends.....................................................100

Wilderness..........................................................................100

. . Status of the system........................................................100

. . Some characteristics of the system.................................100

. . Box 21—Off-highway vehicle participation..................101

—Off-highway vehicle impacts..........................101

Rangeland...........................................................................102

. . Production and consumption..........................................102

. . Valuing grazing use of rangelands.................................102

. . Possible future trends.....................................................103

Summary............................................................................103

Literature Cited....................................................................105
Interim Update of the 2000 RPA Assessment 

This report updates the 2000 Renewable Resources Planning

Act (RPA) Assessment (USDA Forest Service 2001) that

was prepared in response to the mandate in the Forest and

Rangeland Renewable Resources Planning Act of 1974, P.L.

93-378, 88 Stat. 475, as amended. The RPA Assessment

Update consists of this summary report and supporting

documents. The U.S. Department of Agriculture (USDA)

Forest Service has been carrying out resource analysis in the

United States for more than a century. Congressional interest

was first expressed in the Appropriations Act of August 15,

1876, which provided $2,000 for the employment of an expert

to study and report on conditions. Between that time and 1974,

Forest Service analysts prepared a number of assessments

of the forest resource situation intermittently in response to

emerging issues and perceived needs for up-to-date resource

information. The 1974 RPA legislation established a periodic

reporting requirement and broadened the resource coverage

from timber alone to all renewable resources from U.S. forests

and rangelands. Renewable resources in this RPA Assessment

Update include outdoor recreation, fish and wildlife,

wilderness, timber, water, range, and minerals.

Demands and supplies of renewable resources from the Nation’s

forest lands and rangelands are dynamic. Consumers of these

resources accommodate the changing nature of resource supplies

in various ways, including adoption of technologies that change

the ways renewable resource outputs are used. Supplies of

renewable resource outputs change in response to use, management, changing laws, and environmental conditions. Resource

owners and managers respond to the changing demands by

varying the amount and character of resource supplies. In the

future, as in the past, accommodations will be made between

demands and supplies through markets, policy actions, regulations, and management to influence the amount, quality, and

value of renewable resource outputs and conditions. These 

accommodations influence the nature and extent of the forest

land and rangeland estate.

In this review, the outcomes of these accommodations are

presented within the context of the following criteria from the

Montreal Process for conserving and managing U.S. forest

lands and rangelands:

• Conservation of biological diversity.

• Maintenance of productive capacity of forest land and

rangeland ecosystems.

• Maintenance of forest land and rangeland ecosystem health

and vitality.

• Conservation and maintenance of soil and water resources.

• Maintenance of forest contribution to global carbon cycles.

• Maintenance and enhancement of long-term multiple

socioeconomic benefits to meet the needs of society.

• Legal, institutional, and economic framework for forest land

and rangeland conservation and sustainable management.

This context was used to organize the 2000 RPA Assessment

and is used in this RPA Assessment Update to be consistent

with the 2000 report.

Interest in sustainable management of the world’s forest

resources was heightened by the United Nations Conference

on Environment and Development in Rio de Janeiro in 1992.

Since that time, various countries have joined together to

discuss and attempt to reach consensus on ways to evaluate

the management of their forest resources. The United

States is a participant in what has come to be known as the

Montreal Process. The United States, together with Canada,

Japan, Russia, New Zealand, Australia, Republic of Korea,

Chile, Mexico, China, the Russian Federation, Uruguay,

and Argentina, reached a nonbinding agreement on a set of

criteria and indicators for the conservation and sustainable

management of temperate and boreal forests. The criteria are

intended to provide a common understanding of what is meant

by sustainable forest management. The criteria provide a

common framework for describing, assessing, and evaluating a

country’s progress toward sustainability at the national level.

Introduction
Interim Update of the 2000 RPA Assessment
Interim Update of the 2000 RPA Assessment 

The seven criteria resulting from the Montreal Process include

67 indicators of the conservation and sustainable management

of forests. (See http:www.mpci.org/ for more information.) As

reported in the National Report on Sustainable Forests–2003

(USDA Forest Service 2004), data are available on a regular

basis at a national scale for 8 of the 67 indicators, but some

information is available for each indicator. The 67 indicators

are a collection of agreed-upon measures that are indicators

of resource condition. In this RPA Assessment Update, we

report on those indicators from the Montreal Process where

data are available at a national scale. In addition, we add to

the Montreal Process by reporting on important drivers of

change in resource condition and issues such as urbanization

and globalization that cross-cut or affect many measures of

U.S. renewable resource condition. For each of the renewable

resources, we report on projections for selected measures of

future resource use and condition. The capability to integrate

across indicators, drivers, and issues to make a summary

statement about the condition of U.S. renewable resources

remains largely qualitative and subjective.

Organization of the Document
 Interim Update of the 2000 RPA Assessment
Interim Update of the 2000 RPA Assessment 

In this overview of the findings of the RPA Assessment

Update, we present highlights of findings as answers to

commonly asked questions about renewable resource

conditions and policies in the United States.

What’s Behind Expected Changes in Natural Resource 

Conditions?

Population growth—The U.S. population is projected to

grow from 300 million in 2006 to 403 million by 2050.

Population distribution—Population growth continues on

both coasts of the United States, but other fast-growing areas

include the Southwestern United States.

Population composition—The average age is increasing,

the population is more diverse racially and ethnically, and

the population is becoming increasingly urban and suburban

in location and occupation.

Economic growth—U.S. average per capita income will

continue to outpace inflation in the future, increasing the

overall purchasing power of the American public.

The result—The changing U.S. population will likely

demand increased ecosystem services coming from forest

land and rangeland resources, including fresh water,

protection from drought and floods, carbon storage,

recreation, and other cultural benefits.

What’s Happening Across the Landscape?

Total forest land has remained relatively stable at about

750 million acres since 1900, but this stable trend masks

dynamic shifts among forest types, forest age classes, and

how forest cover is arranged on the landscape due to land use

intensification. The area of rangeland has slowly declined from

about 800 million acres in 1900 to approximately 580 million

acres today. Since the middle of the 20th century, rangeland

losses have averaged between 1 and 2 percent per decade.

Forest conversion—More than 50 million acres of nonFederal forests are projected to be converted to urban and

developed uses in the next 50 years.

Net change in forest land—Conversion of pastureland to

forest helps to offset future loss of forest land, but still an estimated net loss of 20 million acres of forest land, primarily

to housing development, is expected over the next 50 years.

Rangeland loss—Rangeland area is projected to decline

slowly over the next 50 years

Increasing urbanization—Urban land is projected to

increase from 3.1 percent of the conterminous United States

in 2000 to 8.1 percent in 2050—an increase in area the size

of Vermont and New Hampshire combined.

Arrangement of forest lands and rangelands—Much

of today’s forests are subject to anthropogenic, or humancaused, “edge effects.” Most large patches of forest are

publicly owned, although urbanization and increasing

intensity of land use on private lands are leading to further

subdivision of these lands.

Parcelization—Nonindustrial private forest land is being

held in increasingly smaller parcels by an increasing number

of owners. Working ranches are also being subdivided into

smaller parcels often called ranchettes.

The result—The interface between humans and natural land

cover will increase as intensified land uses expand. Resulting

edge effects will increase the risks of fire and invasive

species, change the amount and pattern of wildlife habitat

and alter the distribution of air pollution. Collectively, these

changes will increase the challenges to management of

forest lands and rangelands.

How Do Globalization Forces Affect Natural Resources?

Expansion of free trade policies has affected U.S. competitiveness in forest products and mineral and energy resources and

accelerated restructuring and consolidation of the U.S. forest

products industries. The United States is expected to continue

to be a net importer of timber products, as well as numerous

mineral and energy products.

Effects on domestic harvest—High levels of goods imports

and continued high rates of paper recycling result in U.S.

timber harvest increasing at a slower rate than in the last half

of the 20th century.

Effects on measures of forest resource condition—

Imports and loss of domestic processing capacity reduce

domestic timber harvest, which affects the age-class

distribution of domestic forests, which in turn affects habitat

for plants and animals, biodiversity, and other measures of

forest resource condition.

Overview
 Interim Update of the 2000 RPA Assessment

Effects on forest management—A slowing in the growth of

stumpage prices caused by imports reduces expectations for

long-term returns for forest management, raising questions

about incentives for sustainable forest management.

Effects on domestic industrial capacity—Globalization

has been associated with the loss of domestic capacity in

forest industry and several mineral industries. The historical

comparative advantage of some U.S. industries is now

challenged by rising imports and structural changes in

manufacturing. Related impacts are loss of related jobs

and income, which is particularly problematic for naturalresource-dependent communities with few other economic

development options.

Effects of imports on invasive species—Increasing forest

product imports and global commerce in general increase the

risk of invasive species entering the United States.

How Will Climate Change Affect Natural Resources?

Increasingly, the relationship between human-caused emissions

and a warming climate is being documented. Although uncertainty exists in quantifying the impact of emissions on climate,

a global warming of 1.4 to 5.8 degrees centigrade is projected

by 2100. Melting of glaciers, reduction in arctic sea ice, and

rising sea levels are expected to continue. Adapting to climate

change and its potential impacts poses challenges and opportunities for managing resources, infrastructure, and the economy.

Ecosystem responses—The carbon dioxide fertilization

effect on ecosystems is more complex than originally

thought. Research is documenting changes in the breeding

and migrating patterns of animals and flowering of plants,

especially in northern latitudes.

Climate variability—Whether natural or human-induced,

lack of understanding of climate variability limits natural

resource managers’ ability to plan mitigation for climatic

extremes such as droughts, intense rainfall events, or

extreme temperatures.

Effects on forest management toward the range of 

historical variation—Management to mimic the range of

historical variation in resource conditions may no longer

be plausible if climate change overwhelms the intent of the

actions: management must adjust to dynamic conditions.

Other effects—Concurrent with climate change could be

land cover and land use changes, increases in atmospheric

pollutants such as ozone and nitrous oxides, and potential

expansion of exotic plants and animals, some of which may

be considered invasive.

What’s the Role of the Nation’s Forests and Rangelands in 

Carbon Management? 

Forests and rangelands are seen as part of the solution to

reducing atmospheric carbon dioxide and other greenhouse

gases. Carbon management technology and trading are

emerging. The magnitude of the opportunity for carbon storage

and carbon trading is not well quantified.

Forests as carbon sinks—Although forests are expected

to continue to be sinks for carbon, the size of the annual

addition to the sink appears to be declining.

Forests reduce emissions—Trees and forests around

buildings can reduce building energy use and consequently

reduce carbon emissions from power plants.

Wood products as carbon reservoirs or fuel—

Accumulation of wood carbon in long-lived products holds

down carbon dioxide release to the atmosphere; and use of

wood for fuel, when combined with tree regrowth, can offset

carbon dioxide emissions from fossil fuels.

What’s Happening to the Nation’s Biodiversity?

The largest reserves of intact forest are concentrated on public

lands, with the largest share of public intact forest contained

in the National Forest System (NFS). Since private lands can

limit the degree of intactness on adjacent public lands, joint

management may be needed to achieve a specified level of

forest intactness.

Distribution of threatened and endangered species—

Geographic areas where threatened and endangered species

are concentrated have remained unchanged for the past

decade and include the southern Appalachians, coastal areas,

and the arid Southwest. States that have recently lost the

most species occur prominently in the South. More than 30

species have been lost from the biota of California, Texas,

Tennessee, Alabama, and Florida.

Distribution of forest species richness—Data on the

distribution of nearly 700 tree species and nearly 1,500

terrestrial animals show that biodiversity is concentrated in

the Southeast and the arid Southwest. Future concentrations

of biodiversity will be affected by global climate change.
Interim Update of the 2000 RPA Assessment 

Trends in bird biodiversity—Land use intensification

and housing development is associated with reduced native

diversity and increased exotic diversity. Potential impacts

include an overall simplification of biological communities

that may reduce the goods and services that humans derive

from ecosystems.

Where Are All of These People Going To Recreate? 

Recreation demand for forest lands and rangelands in the

United States continues to grow. Population and income

growth, coupled with technological advances in camping and

off-highway transportation, are helping to expand use of our

Nation’s forests and rangelands.

Access to public lands—Primary and secondary home and

resort development adjoining public lands will limit general

public access and allow greater unmanaged recreational use

of those public lands, including off-highway motorized use.

Access to private lands—Increasing closure of private

lands to free public access and shortfalls in funds for public

site and facility management will stress the U.S. public

recreation supply system.

Effects on sensitive ecosystems—Wilderness areas and

special attractions will experience greater congestion at peak

times of the year. Unmanaged motorized uses and heavy

uses in high-elevation alpine ecosystems (e.g., peaks over

14,000 feet) can be especially problematic.

What’s the Role of the Growing Urban Forest?

Urban land is expected to grow from 3.1 percent of the

total area in the conterminous States to 8.1 percent in 2050.

Understanding how and where these urban areas and urban

forests are changing is critical to helping develop policies and

management plans to help sustain this growing resource and its

numerous benefits, and to minimize negative urban effects on

surrounding forests.

Carbon storage—Urban forests sequester an estimated 22.8

million metric tons annually, with total storage in urban

forests estimated at 700 million metric tons.

Air quality—Urban forests can influence air quality by

reducing temperature, removing air pollutants, and altering

building energy use which affects pollutant emissions from

utilities.

Water quality and runoff—Changes in tree canopy cover

affect stream flows and water quality.

Wildlife habitat—Urban forests can provide important

habitats for wildlife.

Quality of life—Besides the numerous environmental

benefits associated with urban forests, these trees also

provide significant social, psychological, and economic

benefits that contribute to the quality of life in urban areas.

Outdoor recreation—Urban forests provide nearby outdoor

recreation opportunities for residents. Some attractions may

be so popular as to decrease pressure for recreation in the

surrounding countryside.

Wildland-urban interface interactions—Urban land

expansion increases the potential for human-caused

pollution and enhances the risk of structural damage from

wildfire. Increasing human population density that occurs

with an expanding wildland-urban interface may also

increase the risk of introducing exotic species into wildlands.

Expansion of urban lands can also displace other land uses

such as timber production.

Where Does Our Water Come From and Will We Have 

Enough?

Water supply—About 53 percent of the Nation’s water

supply originates on forest land, 26 percent on agricultural

land, and 8 percent on rangeland. About 24 percent of the

water supply in the contiguous 48 States originates on

Federal lands and 18 percent on NFS lands alone, even

though these lands occupy only about 11 percent of the

surface area.

Water withdrawals—Water withdrawals in the United

States are projected to increase less than 10 percent over the

next 50 years, although population is expected to increase

more than 40 percent. These increases in withdrawals,

although relatively small, will further diminish instream

flows in rivers and streams across the country. This trend

will add pressure for amending laws and institutions to

facilitate water transfers from low-value to higher-value

water uses. Generally, the quality of water draining from

forests is very good.
 Interim Update of the 2000 RPA Assessment

Where Do Our Timber Products Come From and Will We 

Have Enough?

Current timber supply—At the end of the 20th century,

the United States imported the equivalent of 27 percent of

the consumption of industrial wood used for products, up

from 13 percent in 1965. Most of the imports originated

in Canada, but Brazil, Chile, Finland, and other offshore

countries are increasing in importance for some products.

In 2002, private lands accounted for 92 percent of timber

removals; national forests, 2.1 percent; and other public

lands, the remaining 5.9 percent. In 2002, the South

accounted for 58 percent of the domestic harvest; the North,

21 percent; the Rocky Mountain region, 4 percent; and the

West Coast the remaining 17 percent.

Projected timber supply—Most of the projected increase

in U.S. harvest through 2050 is in nonsawtimber (smaller)

trees, and will come primarily from managed stands in the

South. By 2050, 60 percent of projected softwood harvest

is from managed plantations that occupy about 9 percent

(46 million acres) of total U.S. timberland area. Projected

product imports in roundwood terms will remain around

25 percent of domestic consumption. Aggregate U.S. forest

inventory rises 31 percent for all owners as growth exceeds

harvest over the next five decades. Supplies are generally

adequate to moderate price increases for timber products.

Solidwood product prices rise more slowly than historical

rates and paper and paperboard prices are projected to

decline in real terms. Consumption is expected to increase as

population increases.
Interim Update of the 2000 RPA Assessment 

Although many ideas about sustainability have been put

forward during the past two decades, most are consistent with

the basic concept of sustainable development found in the

1987 Brundtland Commission Report (World Commission on

Environment and Development 1987):

...development that meets the needs of the present without 

compromising the ability of future generations to meet their 

own needs.

The concept of sustainable development links the environment,

society, and the economy. These three basic components or

spheres of sustainable development are often stated as three

interdependent goals of environmental protection, social

well-being, and economic prosperity. Environmental, social,

and economic issues and values must be integrated into our

decisionmaking and actions, while accounting for future, as

well as present, needs.

Sustainable development involves all sectors of society and all

resources. The capacity for sustainable forest management is

often affected by events in other sectors, such as the demand

for housing. The Society of American Foresters adopted the

following statement defining the concept of sustainable forest

management:

“Sustainability as applied to forests is the enhancement 

of human well-being by using, developing, and protecting 

resources at a rate and in a manner that enables people 

to meet their current needs while also providing future 

generations with the means to meet their needs as well; it 

requires simultaneously meeting environmental, economic, and 

community aspirations.”

The concept of sustainability implies that desired future conditions or societal goals are known and that society’s relative

values for desired future conditions are known. As pointed out

in the National Report on Sustainable Forests—2003 (USDA

Forest Service 2004), however, neither desired future conditions nor relative societal values are known for the U.S. forest

situation. This RPA Assessment Update provides further information for readers to use in making judgments about the status

and trends in the U.S. renewable resource situation.

Concepts of Sustainable Development and Sustainable Forest Management
10 Interim Update of the 2000 RPA Assessment
Interim Update of the 2000 RPA Assessment 11

World Context

Worldwide growth in population and income has contributed

to the evolution of issues related to the environment that are

mirrored in domestic issues. The basic dynamics of population

change contribute to social, economic, and technological

change that can have profound effects on the ways that the

renewable resources of the world are managed and used. After

the Second World War, growth of the world’s population and

the economies of some countries forever altered ecosystems

in many parts of the world. World population more than

doubled from 2.5 billion people in 1950 to 6.4 billion in 2004

(U.S. Census Bureau 2005). Much of this growth was in the

developing countries where population increased from 1.7 to

4.9 billion people during this time. One person in three now

resides in India or China. Population in the developed countries

increased from 800 million to 1.2 billion people.

Between 1950 and 2004, the population of the United States

as a percent of the world population declined from 6 to 4.5

percent. Overall, the United States had about 78 people per

square mile of land in 1999 (U.S. Census Bureau 2001). These

figures compare with the world average of 119 people per

square mile (Food and Agriculture Organization of the United

Nations 2005a).

The Food and Agriculture Organization of the United Nations

(2005a) projects world population to grow from 6.5 billion

people today to 9.1 billion in 2050. Under the terms of the

medium projection, the rate of growth in population will

continue to decline in the future to 0.5 percent in 2045–50,

down from a peak rate of growth of 1.2 percent in the period

2000–05. Although uncertainties are present with any

projections, there is little doubt that there will be significant

growth in world population with implications for resource use,

carbon emissions, and other renewable resource issues that

transcend national boundaries.

The population of more developed regions, currently at 1.2

billion, is anticipated to change little during the next 50 years

with 30 countries actually projected to experience declining

populations. The population of the less developed regions is

projected to rise steadily from 4.9 billion in 2000 to 8.1 billion

in 2050.

Through the 1970s, much of the income growth was in the

developed countries. In the past two decades of the 20th

century, liberalization of trade and many other factors

contributed to income growth in some developing countries

such as China and India. This growth in developing countries

coincided with a general maturation of the economies of the

developed countries. Thus, much of the change in the world

economy originates in the developing countries.

Gross domestic product per capita in the United States was

5.5 times the world total in 1995 (World Resources Institute

et al. 1998). Although per capita incomes in some developing

countries such as China and India have increased in the past 20

years, others remain impoverished.

Population and income growth, changing societal values, and

many other factors contributed to the development of various

issues related to the environment during the last half of the 20th

century. Growth in population often led to deforestation for

agriculture in developing countries. Patterns in international

trade often resulted in exports of forest products from

developing to developed economies, leading to concerns over

trade and the environment. Development of all types led to

concern about diminishing biological diversity and increasing

numbers of endangered species, and it is increasingly clear

that the causes and outcomes of climate change transcend

national boundaries. The United States’ interests in these issues

are reflected in the fact that we are signatories to the United

Nations Convention to Combat Desertification, the Convention

on International Trade in Endangered Species of Wild Fauna

and Flora, and the International Tropical Timber Agreement.

In addition, U.S. representatives have participated in the

Social and Economic Context for the Interim Update of the 2000 RPA Assessment
12 Interim Update of the 2000 RPA Assessment

plantations increase in importance as a source of wood fiber

(see box 2). Bilateral trade issues in forest products remain

such as Canadian exports of softwood lumber and Chinese

exports of furniture to the United States. We are connected to

the rest of the world through trade. Imports of timber products

can affect domestic forest resource conditions; imports

of minerals can affect domestic mineral production, and

international trade can affect domestic land use (see box 3).

Globalization, consolidation, and structural change in the 

U.S. forest sector—A general definition of “globalization”

is the ongoing expansion of global interconnectedness in

society and culture, associated with reduced territoriality,

higher speed of social activity, and long-term structural

changes with multifaceted aspects (Stanford Encyclopedia

of Philosophy [http://plato.stanford.edu]). Economic

globalization is reflected in expansion of global

interconnectedness in commerce, business, and capital

investments. Structural change includes the competitive

replacement of older and less efficient means of production

by more efficient means of production, a process unlikely

to be reversed. The U.S. forest products industries have

a long history of structural change as timber harvesting

moved around the country, and as technology and consumer

demands evolved. At times, these market forces led to

consolidation of capacity. Structural change is generally

thought to result in economic gains over the long run, but

possible negative consequences can include local job losses,

economic instability, shifts in capital flows, or declines

in local market demands for resources. Globalization can

accelerate or alter the nature of structural change.

Globalization, consolidation, and structural change during

the past decade contributed to a recent decline in domestic

consumption of certain forest products (paperboard products

and wood pallets used for packaging and shipping as well as

paper used for print advertising), with corresponding loss of

industrial capacity and related jobs, increased imports, and

lower stumpage prices. According to Ince et al. (n.d.), globalization and structural change contributed to the following:

• Domestic consumption of paper and paperboard declined

by 7 percent from a peak of 103 million tons in 1999 to 96

million tons in 2003, and then increased by 4 percent in

2004 (American Forest and Paper Association 2005).

• According to the Forest Resources Association (for more

information, go to http://www.forestresources.org/), by

2002 annual volumes of pulpwood received at U.S. pulp

mills declined by 16 percent since peaking in 1994 and

volume rose by 4 percent from 2002 to 2004.

• Domestic hardwood lumber consumption in furniture

declined from 3.3 billion board feet in 2000 to about 1.7

billion board feet in 2003; for pallets, the decline was

from about 5 billion board feet to 3 billion board feet.

• Economic globalization contributed to significant abatement of growth in U.S. timber harvest because some processing capacity was lost to competitors in other countries.

• About one out of every six paper and paperboard mills has

closed since the mid-1990s.

• One out of every three jobs at U.S. pulp and paper

mills has been eliminated since the early 1990s

due to consolidation, cost-cutting, and productivity

improvements.

• Nearly 40 North Carolina furniture plants have closed

since 2001.

• The number of major softwood sawmills in the United

States declined from 850 in 1995 to 700 in 2004, with

a 37-percent increase in average capacity as older mills

were replaced with larger ones.

• In the 1990s, imports as a percent of U.S.sales of wood

household furniture increased from 20 to more than 50 percent

and continuesto expand, primarily importsfrom China.

Box 1

Framework Convention on Climate Change and the Convention

on Biological Diversity. Thus, the rest of the world is trying to

deal with many of the same environmental issues that are being

debated domestically in the United States.

The issues will likely change over time. For example,

globalization has become an issue in the forest product and

other manufacturing industries (see box 1). Biodiversity

and other issues concerning plantations will likely grow as
Interim Update of the 2000 RPA Assessment 13

Box 1 (continued)

• Since 1990, imports of softwood lumber increased from

27.1 percent (12.1 billion board feet) of consumption to 38

percent (25 billion board feet).

• Imports of oriented strand board increased from 1.3 billion

square feet (19 percent of consumption) in 1990 to 8.5

billion square feet (39 percent of consumption) in 2002.

• Southern pine pulpwood stumpage prices peaked about

1997, declined to half that level by 2002, and have not

recovered to previous peak levels.

Globalization and structural change have contributed

declines in exports of timber products from the United States.

New suppliers have emerged in world markets and the nature

of demand has changed for some countries. For example,

softwood log export volume from the four West Coast States

declined from 3.7 billion board feet in 1990 to less than 1

billion board feet in 2003. Much of the decline was due to

reduced shipments to the People’s Republic of China, Japan,

and South Korea. Exports of softwood lumber, plywood, and

wood chips from the United States have also declined.

Structural change and economic globalization have many

implications for evaluation of the status and trends of

renewable resources. For example, imports of timber

products decrease domestic harvest and thereby affect

commonly used measures of resource condition such as the

growth removal ratio for roundwood. Structural change and

globalization should also be key considerations in evaluation

of future returns from forest management because they affect

stumpage prices and costs of forest management.

Box 2

Plantations1—According to the Food and Agriculture

Organization (FAO) of the United Nations (2005b),

plantations account for 1.4 percent of global land area

with tree cover, but only a fraction are industrial wood

plantations. Most tree plantations serve other purposes such

as soil conservation, or cultivation of crops such as nuts, or

extractives, such as rubber plantations. An FAO analysis

(2001) suggests that most countries will move away from the

use of natural forest resources for wood and fiber production

toward other land-based and non-land-based sources of

supply, including the use of wood processing residues and

recycled fibers.

Fast-growing industrial wood plantations occupy less than

2 percent of forested area worldwide, yet they supply onequarter of all industrial roundwood. Furthermore, plantations

are projected to supply half of global wood resource needs

within two decades (Australian Bureau of Agricultural and

Resource Economics and Jaako Poyry Consulting 1999).

Haynes (2003) projected that timber supply from fastgrowing managed plantations in the United States (primarily

southern pine plantations) will approach one-third of total

U.S. timber supply and more than half of softwood timber

supply, and will account for most projected increases in

timber supply in the decades ahead. Yet managed plantations

were projected to increase from only 6 percent of U.S.

timberland area to about 9 percent by the year 2050. Since

harvest is reduced on the remaining timber land, there are

many implications for indicators of resource condition and

trend on these lands.

The 2005 RPA timber assessment update (Haynes et al.

2006) projects a more modest but continued expansion in the

area of southern pine plantations. Real hardwood pulpwood

prices are projected by then to reach levels that will stimulate

competitive expansion of hardwood short-rotation woody

crops on agricultural land, and by 2050, the projected output

is 100 million cubic feet per year.

1 Defined by Smith et al. (2001) as forest stands consisting almost exclusively as planted trees, of native or exotic species, and intensively managed to

maintain this composition to maturity. Management practices may include extensive site preparation prior to planting and suppression of competing

vegetation.
14 Interim Update of the 2000 RPA Assessment

Box 3

Trade and the environment

Effects of imports of timber products on domestic forest 

resource conditions—From a small net export situation at

the start of the 20th century, U.S. trade in timber products

evolved into a deficit situation in volume terms (Hair and

Ulrich 1964). Imports as a percent of consumption increased

from 13.1 percent in 1965 to 27.2 percent in 2002 (fig. 1).

Because imports have increased, U.S. harvest has been

lower than it would have been without increasing imports.

Imports also have the effect of dampening domestic prices

for roundwood, thereby decreasing the incentive for forest

management. Lower harvest could affect all indicators

of renewable resource condition and trends. Exports as

a percent of production have also decreased. In addition,

increased U.S. imports of manufactured goods in general and

broad displacement of U.S. manufacturing by imports, have

directly affected U.S. demands for some forest products,

such as demands in manufacturing for paper or paperboard

packaging, wood product use in industry, and demands for

paper in print advertising.

Effects of imports of minerals—The United States is nearly

100 percent dependent on imports as a source of bauxite,

chromium, cobalt, and the minerals in the platinum group

(table 1).1 Of the minerals in table 1, we are self-sufficient

in copper and nearly self-sufficient in iron ore and lead.

Japan is the most dependent on imports as a source of

minerals although Russia is the most self-sufficient of the

four industrialized areas. Many of the energy and mineral

resources used by industrialized societies are imported

from developing nations, some with fragile economies

and unstable governments. The production of minerals is a

driving force in many nations’ economies. A low correlation

exists, however, between the production and export of a

mineral endowment and widespread economic prosperity

in many developing countries. As with most commodities,

imports of minerals dampen prices. This situation means that

some deposits of minerals in the United States are not mined

at current prices because of imports.

Effects of trade on land use—The quality of forest land

conditions can be affected by trade. In our interdependent

world economy, land-based sectors such as forestry and

agriculture have significant trade components. Such trade

affects product prices and land prices, thereby possibly

influencing land allocation among sectors of the economy.

For example, increased agricultural export demand can

lead to reduced area in forest, given the fixed land base

(Alig et al. 1998). In early decades, clearing of bottomland

hardwood areas in the South was prompted by increased

export demand for soybeans. Farm subsidies can compound

the effects in land markets, in that they can affect the amount

of agricultural trade, as well as the allocation of land between

the forestry and agricultural sectors (Alig et al. 1998).

1 Personal communication with Deborah Shields, Rocky Mountain Research Station, Fort Collins, CO.

Figure 1.—Imports as a percentage of consumption and 

exports as a percentage of production of industrial wood.

30

25

20

15

10

5

0

1965 1970 1975 1980 1985 1990 1995 2000

Imports Exports
Interim Update of the 2000 RPA Assessment 15

Box 3 (continued)

Table 1.—Mineral import reliance (net imports as a percent of consumption) of selected regions as of 1997. A value of 0 

indicates that the region is a net exporter.

United States Japan Russia European Union

Bauxite 99 100 21 80

Chromium 100 100 78 57

Copper 0 100 17 86

Cobalt 100 100 0 100

Iron ore 16 100 1 83

Lead 10 97 0 68

Platinum group 94 100 0 100

Source: British Geological Survey (2006). 

Commodity trade is now only one among a number of ways in

which producers, consumers, resource managers, and policy

makers must consider the international context of their decisions.

Integration of national economies, and therefore natural resource

conditions, also takes place through foreign investment and

through multinational corporations. The interdependence of the

U.S. forest sector with other countries—through trade, investment, and international agreements and policy processes—is

likely to expand and become increasingly complex.

U.S. Context

The condition and trend in renewable resources are affected

by changes in the Nation’s population and the way in which

people deploy themselves on the landscape. In 1900, most of

the Nation’s people lived in the East and were concentrated in

the mid-Atlantic and Lake States regions. By 1999, the most

heavily populated places were along the coasts (fig. 2) (Cordell

and Overdevest 2001). Migration to be close to amenities such

as recreational opportunities on national forests helps to explain

some of the settlement pattern (see box 4).

Each year, hundreds of thousands of people move to or from

the United States. By 2000, net migration into the United States

was estimated to be 970,000 people. The legal immigrating

population to this country is moving into all of its regions.

Figure 2.—Population per square mile by county in the 

contiguous 48 States in 1970, 2000, and 2025.

0–50

51–150

151–400

401–1,000

1,001+

States Population 

Density
16 Interim Update of the 2000 RPA Assessment

Box 4

Amenity migration—Increasingly, the U.S. population is

choosing places to live on the basis of factors other than employment. The net increase or decrease in an area’s population through migration is driven by many agents, including

economic factors (job location, income differential), life

courses changes (attending college, retirement), and noneconomic factors (physical attractiveness of the area, pace of

life). People who choose their new area of residence based

on its natural resources, recreation opportunities, and esthetic

qualities are referred to as amenity migrants (Garber-Yonts

2004, Johnson and Stewart 2005). Since the 1970s, amenity

migration has stimulated considerable population growth in

rural areas rich in natural resources.

Measuring amenity migration is difficult because amenities

are subjective and personal preference determines what

resources are attractive. For this RPA Assessment Update,

counties were classed according to their amenities, recreation

opportunities, retirement allure, and whether or not national

forests make up more than 10 percent of the county’s land

area. Counties with concentrations of national forests had

demographic gains similar in size and structure to amenity,

recreation, and retirement counties during the 1990s (fig. 3).

In each county type, gains were fueled by net migration, and

it is likely that amenities draw most of the migrants.

Amenity migration is bringing new people to rural areas,

and with them, new demands for housing, infrastructure,

government, and retail services, and a host of environmental

services. Of particular interest to planners is the possibility

that population growth is likely to increase the population

density along the forest edge, putting additional pressure

on riparian and environmentally sensitive areas, increasing

the demand for recreational facilities, and complicating

forest management and fire suppression. Retirees make

up a large percentage of amenity migrants. If the “Baby

Boom” generation makes retirement decisions similar to

the decisions made by people in the 1990s, the likelihood

of accelerating population growth in amenity rich areas is

extremely high (fig. 4).

Figure 3.—Demographic change from 1990 through 2000 

by county type.

Figure 4.—Age-specific net migration: nonmetro national 

forest.

Analysis: K.M. Johnson, Loyola University Chicago

Sources: U.S. Census Bureau; USDA Forest Service; USDA Economic 

Research Service; Johnson and Beale (2002)

Analysis: Johnson, Voss, Fuguitt, Hammer and McNiven (2003).

Data: U.S. Census Bureau
Interim Update of the 2000 RPA Assessment 17

Almost 43 percent of foreign-born persons living in the North

had moved into that region between 1990 and 2000; for the

Rocky Mountain region, the similar percentage was 49 percent;

for the South, 46 percent; and for the Pacific Coast, 38 percent.

The U.S. population continues to diversify. In 1900, 87.9

percent of the U.S. population was classified as non-Hispanic

white, 11.6 percent was classified as non-Hispanic black, and

the remainder was American Indian, Asian, or Pacific-Islander.

By 1950, whites composed 89.5 percent of the population and

blacks 10 percent. Change in U.S. immigration law and policies

in the 1950s and 1960s led to a much-changed composition of

the U.S. population. The Immigration Act amendments of 1965

(also known as the Hart-Celler Act) amended the Immigration

and Nationality Act of 1952. The 1965 Act abolished the

national origin quotas and established a policy that gave

priority to family reunification and to bringing those who had

certain “desirable or needed skills” regardless of nationality. By

2000, non-Hispanic whites were 69.1 percent of the population,

Hispanics were 12.5 percent, blacks were 12.3 percent, Asians

were 3.6 percent, and American Indians were 0.9 percent.

Much of the growth in the minority (other than non-Hispanic

white) population is expected to occur in the upper Midwest,

the Pacific Coast, Florida, and parts of the West (fig. 5).

On average, people are living longer in the United States. In

1900, the average life span expected for persons born that year

was 46.4 years for males and almost 49 years for females. By

1950, the corresponding data was 65.6 years for males and 

71.1 years for females and, in 2000, 73.7 years for males and

79.4 years for females.

In 1900, less than 5 percent of the U.S. population was 65 or

older. By 2000, more than 12 percent were in this age group.

By contrast, in 1900, about 45 percent of the population was

less than 20 years of age. By 2000, less than 30 percent of

the population was under 20 years of age. The changing age

composition of the population has many implications for

entitlement programs such as social security, societal values,

and demands for goods and services. For example, projected

changes among counties with populations age 65 or older are

mainly in the West and South (fig. 6).

Over time, the economic diversity of the Nation has changed,

reflecting population movements, changes in technology, and

a host of other factors. After the Second World War, growth in

income and increases in leisure time led to increased demands

for outputs of ecosystems as well as recreation and other values

for these systems. For example, real gross domestic product

increased by 50 percent between 1960 and 1970 (fig. 7).

Changing societal values are reflected in Federal legislation that

has been passed over the past several decades. Key legislation

includes the Multiple Use-Sustained Yield Act of 1960, the

Wilderness Act of 1964, the National Environmental Policy

Figure 5.—Percent change in minority population by county 

from 2000 to 2025 in the contiguous 48 States.

–60–42.8

42.8–72.6

72.6–109.7

109.7–155

155–966.7

States Minority, 

change 2000 to 2005

Figure 6.—Projected percentage change among counties 

with populations age 65 and older in 2000 and 2025.

–27.8–28.6

28.6–53.2

53.2–76.9

76.9–115.9

115.9–1,521.5

States Population > 65, 

change 2000 to 2005
18 Interim Update of the 2000 RPA Assessment

income and thus more opportunity to enjoy the Nation’s

natural resources (fig. 9). This projection does not mean

that population and income will increase uniformly across

the country. For example, population growth in the Great

Plains is likely to be small while growth in Florida, Texas,

and California is likely to be relatively large. Any long-term

economic projections are fraught with uncertainty, especially

with consideration of globalization and implications for energy

and other key essentials of modern living.

Figure 7.—Real gross domestic product ($2,000).

Figure 8.—U.S. population.

Figure 9.—Projected per capita disposable personal income.

1 Data for U.S. forest land, rangeland, agricultural lands, and wetlands are maintained by the Natural Resources Conservation Service. At the time of

publication of this report, the latest available data are for 1997.

Act of 1970, the Endangered Species Act of 1973, the Forest

and Rangeland RPA of 1974, the National Forest Management

Act of 1976, and the Forest and Rangeland Renewable

Resources Research Act of 1978. These and other legislated

mandates provide direction to Federal agencies in management

and protection of values associated with ecosystems found

on Federal lands. Many of the environmental policy issues

grow out of the public’s perceptions of how these mandates

are implemented and how values are protected. These values

change over time (see box 5).

Demands on the Nation’s forest land and rangeland ecosystems

will continue to increase. By 2055, the population of the

United States is projected to increase 45 percent, or by more

than 129 million people (fig. 8) (U.S. Census Bureau 2004).

During the past 50 years, the population increased by about 121

million. The population is projected to have more discretionary

Land Use and Cover in the United States1

Human land use is the primary force driving changes in

ecosystem attributes. Through management and use of

ecosystems, human land use affects all aspects of sustainable

forest management. Thus, land use and cover are important

aspects of the social and economic context for understanding

the status and trends in U.S. renewable resources.

Changes in land use and cover can affect wildlife habitat,

riparian and wetlands, risk of damage by insects and diseases,

introduction of exotic species, and water quantity and quality,

as well as the use of forests and rangelands for recreation. Data

for changes in land use are based on the National Resources

Inventory (NRI) conducted by the USDA Natural Resources

Conservation Service (NRCS) (2000). The NRI is an inventory

of land use on non-Federal lands. Much of the publicly owned

forest land is stable in terms of land use.

1959196219651968197119741977198019831986198919921995199820012004

12,000

10,000

8,000

6,000

4,000

2,000

0

20102020203020402050

50,000

45,000

40,000

35,000

30,000

25,000

20,000

15,000

10,000

5,000

0

500,000

450,000

400,000

350,000

300,000

250,000

200,000

150,000

100,000

50,000

0

$1996

Thousands

19802000202020402050
Interim Update of the 2000 RPA Assessment 19

Box 5

Values change over time—Bengston et al. (2004) characterized forest value orientations in three ways. An anthropocentric/utilitarian value orientation suggests that providing for

human use and benefits is the primary aim of natural resource

allocation and management. A biocentric value orientation

emphasizes primary goals such as environmental protection,

preservation, and ecosystem health and integrity. The moral/

spiritual/aesthetic value orientation emphasizes the noninstrumental values of forests such as bequest values. Content analysis was used to review 8,379 stories about forest

planning, management, and policy found in seven national

newspapers, news magazines, and newswires over the period

January 1, 1980 to May 1, 2002. Major national news sources

such as these have been found to accurately reflect the national debate and public opinions about the environment and

other policy issues. The analysis counted the number of expressions of each of the forest value orientations.

Figure 10 shows the share of each value orientation as a

percent of total value expressions over time. The share of

utilitarian value expressions declined significantly over time.

Commodity production is still an important use of public

lands, but other, nonconsumptive uses and related values

have increased in relative importance. The share of biocentric

value expressions increased and the share of moral/spiritual/

aesthetic value orientation has remained constant over time.

Bengston et al. (2004) point out that drivers of changing

forest values in the future will likely include continued

declines in the economic importance of primary commodity

industries, urbanization and the blurring of boundaries

between urban and rural areas and values, and continued

strong demand for environmental amenities and quality.

Demographic changes such as rapid population growth and

growing racial and ethnic diversity will also help shape our

changing relationships with forests.

Cordell et al. (2004) found that utilitarian values such as

production of wood products rank lower than biocentric

and moral/spiritual/aesthetic value orientations in peoples’

preferences for management of publicly owned forests.

the total area of temperate and boreal forests. The total area

of forest land in the world has been decreasing at least since

1980 (Food and Agriculture Organization of the United Nations

2001). Most of the decrease has been in the developing tropical

countries. Forest area in several developed countries such as

Norway, France, and New Zealand has been increasing. The

net area of forest land in the United States has been relatively

stable since the 1920s, with decreases due to development

and other land uses being offset by afforestation and natural

reversion of abandoned crop and pastureland to forest land. We

Forest land—The area of the world’s forests is estimated to

be 9.6 billion acres as of 2005, or about 30 percent of the land

area of the Earth (Food and Agriculture Organization of the

United Nations 2005b). About 55 percent of the world’s forests

are located in developing countries and 45 percent in developed

countries. The world’s forests are almost equally divided

between tropical/subtropical and temperate/boreal.

The U.S. forest land area of 749 million acres amounts to about

8 percent of the total world forest land area and 12 percent of

Figure 10.—Forest value orientations in the United States.
20 Interim Update of the 2000 RPA Assessment

have 2 acres of forest land per person, which is more than the

world average of 1.5 acres per person (Food and Agriculture

Organization of the United Nations 2005b).

The United States is not alone in having a high proportion of

forest land in private ownership (57 percent). Among other

countries, Austria, Finland, France, and Japan have more

than one-half of their forest and other wooded land in private

ownership (United Nations Economic Commission for Europe

and Food and Agriculture Organization of the United Nations

2002). By contrast, only 6.5 percent of Canada’s forest and

other wooded land is in private ownership.

According to NRCS (2000), forest land area had a net increase

of about 3.6 million acres on non-Federal lands between 1982

and 1997 (table 2). This acreage amounts to less than 1 percent

of the area that existed in 1982. Losses to other uses were

more than offset by gains from other land cover categories.

The largest loss of forest land was to development (10.3

million acres or 2.6 percent of the area in 1982). The largest

gain in forest land was from pasture land (14.1 million acres

or 3.5 percent of the area in 1982). In total, 23 million acres

of forest land (5.7 percent of the area in 1982) was converted

to other uses between 1982 and 1997 while 26.6 million acres

(6.5 percent of the area in 1997) were added to the forest land

classification, resulting in a net gain of 3.6 million acres of

forest land.

Rangeland—Rangeland occupies nearly one-half of the

Earth’s land area or about 16.1 billion acres (Food and

Agriculture Organization of the United Nations 1990). About

one-half of this area is used for grazing livestock. Total world

change in rangeland area amounts to less than 0.1 percent per

year. This net change masks regional shifts: Niger, India, and

Mongolia are losing pasture land at a much higher rate than

South American countries, particularly Brazil, are gaining it.

Much of the gain in rangeland area in the Tropics is attributable

to conversion of rain forests. Although a consensus definition

for rangeland area is elusive, the rangeland area of the United

States amounts to about 5 percent of the total area of rangeland

in the world (Mitchell 2000).

Between 1982 and 1997, non-Federal rangeland area

nationwide had a 2.6 percent net loss (table 2). Of those acres

Table 2.—Changes in land cover/use between 1982 and 1997.

Read this table horizontally to determine how a particular 1982 land use (row heading) was distributed in 1997 (column headings). Read this table vertically to 

determine where a particular 1997 land use (column heading) came from in terms of 1982 land uses (row headings).

CRP = Conservation Reserve Program.

Land

Water 

cover/use in

CRP Forest Other Developed areas & 1982

1982

Cropland land Pastureland Rangeland land rural land land Federal total

 land

1,000 acres 

Cropland 350,265.3 30,412.1 19,269.4 3,659.2 5,606.5 3,158.9 7,097.5 1,485.1 420,954.0

Pastureland 15,347.0 1,329.6 92,088.3 2,567.9 14,091.4 1,619.0 4,230.0 732.8 132,006.0

Rangeland 6,967.5 728.5 3,037.2 394,617.4 3,021.6 1,702.7 3,281.3 3,383.2 416,739.4

Forest land 2,037.1 128.8 4,168.2 2,098.8 380,343.3 1,754.8 10,279.2 2,528.0 403,338.2

Other rural land 1,386.8 93.1 1,013.6 719.1 2,767.7 42,713.3 726.9 227.8 49,648.3

 

Developed land 196.7 1.2 78.6 110.8 227.0 12.0 72,618.7 0.8 73,245.8

 

Water areas 797.5 2.7 336.6 2,204.0 897.7 180.8 18.1 443,760.6 448,198.0

 and Federal

 land

1997 total 376,997.9 32,696.0 119,991.9 405,977.2 406,955.2 51,141.5 98,251.7 452,118.3 1,944,134.7
Interim Update of the 2000 RPA Assessment 21

that were rangeland in 1982, 5.3 percent were converted to

another land use class in 1997. Of these converted acres, the

largest proportion was converted to cropland (31.5 percent),

just over 14.8 percent was converted to developed land, 13.7

percent was converted to pasture land, and 13.7 percent was

converted to forest. It should be noted, however, that exurban

developments on lot sizes exceeding 10 acres are not captured

as a land use change by the NRI, although subdivision of

ranches into ranchettes is common where population is growing

in the West.

Rangeland supports habitat for some wildlife species and

provides the settings for hunting and other recreation activities.

In evaluating the state of rangeland habitats, it is important to

recognize that present land use dynamics do not indicate the

extent to which certain rangeland systems have been altered

historically. Many rangeland ecosystems underwent extensive

conversions long before land-based inventories were designed.

Grazing, agricultural development, fire suppression, urban

development, and exotic species invasions are primary agents

of rangeland alteration. Tallgrass prairie habitats have been lost

primarily to agriculture development. Eastern and northwestern

grasslands and savannas have been lost to urban development,

agriculture, and fire suppression.

Agricultural lands—Agricultural lands consist primarily

of lands used to produce food, feed, fiber, and oilseed crops

and are described as cropland and pasture land. Cropland is

classed as cultivated and noncultivated. Cultivated cropland is

annually planted for commodities including rowcrops such as

corn, soybeans, and cotton or small grains such as wheat and

oats. Noncultivated cropland consists of land planted to multiyear or perennial crops such as hay, horticultural plants, and

orchards. Pasture land is used for livestock grazing and differs

from rangeland in the level of management it receives. Pasture

lands are planted with introduced or domesticated native forage

species and receive periodic cultural treatments such as tillage,

fertilization, mowing, weed control, or irrigation. Agricultural

lands provide food and cover used by many species of wildlife

and many agricultural cropping practices are used in managing

habitats for wildlife. They also provide significant opportunities for outdoor recreation and are important for water quantity 

and quality.

From 1982 to 1997, cultivated cropland had a net decline of

10.4 percent (table 2). This net loss of 44 million acres resulted

from 26.7 million new acres being converted to cultivated

cropland while 70.7 million acres of cultivated cropland

went to other uses. Of those 70.7 million acres of converted

cropland, 43 percent was enrolled into the Conservation

Reserve Program (CRP), 27.3 percent was converted to

pasture land, and 10 percent went to developed land. The

CRP removed highly erodible land out of crop production and

established perennial vegetative cover for 10 to 15 years. The

1990 Farm Bill capped CRP acreage at 36 million and created

an environmental benefits index that gives preference to lands

being bid that will improve water quality and wildlife benefits.

Although pasture had only a net decline of 9.1 percent from

1982 to 1997, 30.2 percent of the 1982 pasture was converted

to another use category. Some 38 percent of the pasture loss

went to cropland and 35 percent reverted to forest land.

For the most part, farms have become larger and are now

characterized by larger field sizes, reduced crop diversity, and

a loss of wildlife habitats provided by fencerows and wetlands.

These changes reduce the amount of vertical and horizontal

wildlife habitat diversity.

The CRP has potential to directly improve wildlife habitat

associated with agriculture. Enrollments in the CRP have

shown local benefits to some nesting birds such as the ringnecked pheasant.

Wetlands—Wetlands are characterized by constant or recurrent shallow inundation, or saturation, at or near the surface.

Wetland ecosystems are very productive and they are critical to

flood and erosion control, aquifer recharge, and water purification. The inherent productivity of wetlands supports a diversity

of wildlife and fish that are important to commercial fisheries,

furbearer harvests, waterfowl hunting, recreational fishing, and

nonconsumptive outdoor recreation and nature study.

During the early settlement period of America, wetlands were

perceived as an impediment to economic development and, up

until the mid-1970s, wetland drainage and conversion was an

accepted land use policy. Historically, agricultural development
22 Interim Update of the 2000 RPA Assessment

was the primary economic force in the conversion of wetlands.

The loss of wetland area slowed from 460,000 acres per year in the

1950s to mid-1970s to 260,000 acres per year in the mid-1970s to

mid-1980s and to 100,000 acres per year during the 1990s.

Causes of conversion of wetland habitats have now shifted

away from agriculture to urban development (fig. 11). Urban

and built-up land was responsible for 49 percent of the wetland

acres that were converted during the 1992 to 1997 period,

whereas agricultural development was responsible for 26

percent. Much of the pressure from conversion to urban and

built-up land is likely due to continued development along

coastal areas in the North and South.

Urban lands—Urban land2 in the conterminous United States

increased from 2.5 percent of the total land area in 1990 to 3.1

percent in 2000. This urban growth is equivalent to an area

about the size of Vermont and New Hampshire combined.

States with the greatest increase in the percent of urban land

between 1990 and 2000 were Rhode Island (5.7 percent),

New Jersey (5.1 percent), Connecticut (5.0 percent), and

Massachusetts (5.0 percent) (Nowak et al. 2005). Much of the

increase in the percent of urban land by county is clustered

in specific areas of the Southeast, Midwest, Northwest, and

California, but is particularly evident along the northeastern

seaboard (fig.12).

Basing information on the historical growth pattern between

1990 and 2000, urban land is projected to increase from 3.1

percent of the conterminous United States in 2000 to 8.1 percent in 2050 (Nowak and Walton 2005) (fig. 12). This projected

urban growth is larger than the State of Montana. Urban expansion is projected to be greatest near the most urbanized regions.

Urban areas are expanding at an increasing rate and will

likely subsume significant amounts of exurban lands over the

next 50 years, particularly in areas adjacent to existing urban

lands. This urban shift will have significant impacts on natural

resource management, and will increase the demands on urban

forest management to help sustain environmental and human

health in and around urban areas. The existing urban forests

currently provide considerable benefits and the importance of

this resource may increase in the future if these benefits can be

Figure 11.—Causes of conversion of wetland habitats.

Figure 12.—Projected percentage of land classified as urban 

in 2000 (12a) and 2050 (12b) by county.

2 Defined as all territory, population, and housing units located within either urbanized areas or urban clusters: a cluster of one or more block groups or

census blocks with a population density of 500 people per square mile, surrounding block groups with a population density of 500 people per square mile,

or less densely settled blocks that form enclaves or indentations or are used to connect discontinuous areas.

(12a)

(12b)
Interim Update of the 2000 RPA Assessment 23

maintained. Understanding how and where these urban areas

and urban forests are changing is critical to helping develop

policies and management plans to help sustain this growing

resource and its numerous benefits, and to minimize negative

urban effects on surrounding forest areas.

When an area is converted to urban and built-up uses, it is

likely to be a permanent conversion. Conversion of rural lands

to urban and other built-up uses affects the mix of commodities

and services produced from the U.S. land base. Between 1982

and 1997, the amount of U.S. land devoted to urban and builtup uses increased 34 percent, an amount that was larger than

the percentage increase in population. Newly developed lands

are coming predominantly from the conversion of croplands

and forest land. The largest increases in U.S. developed areas

between 1982 and 1997 were in the South, with major driving

factors being growth in population and personal income (Alig

and Plantinga 2004). Projected potential future urbanization

and development indicate increases by about 80 percent by

2025, based on a projected 35-percent increase in the U.S.

population and a projected significant future increase in real

personal income. The magnitude of projected increase in

developed uses varies by region. Developed area is projected

to increase from 5.2 percent to 9.2 percent of the land base by

2025. More people on the forested landscape often means loss

of open space and concern over the values generally associated

with open space (see box 6). The growing concerns about the

loss of forest land to development have also been reflected in

public and private efforts to preserve forest land as open space

(Kline et al. 2004). Because much of the growth is expected

in areas relatively stressed with respect to human-environment

interactions, such as some coastal counties, implications for

landscape and urban planning include potential impacts on

sensitive watersheds, riparian areas, wildlife habitat, open

space, and water supplies (see box 7).

Box 6

More people on the forested landscape—Forest land

development raises several issues for managers and policy

makers associated with the manner in which development

affects landscape patterns and conditions, and the goods

and services provided by forests. More people on the

forested landscape generally means increased parcelization

(the breaking up of large parcels into smaller parcels for

development) which can lead to conflicts with existing land

uses. Forest land development can also have ecological

effects in loss of habitat, landscape fragmentation, and

changes in vegetation structure brought about by changing

land uses. Socioeconomic effects can result from loss of

access and the supply of open space for outdoor recreation

and aesthetic enjoyment, just as demands for these services

might be increasing. These changes can result in increasing

political pressure for greater regulation of management

practices. Other policies and programs intended to slow

forest conversion include State use-value assessment

programs that reduce property taxes on forest and farm lands,

and programs that purchase development rights, conservation

easements, or land in fee simple.

As the U.S. population grows, continued development of

forest land seems inevitable. According to Stein et al. (2005),

much of the privately owned eastern forest land will be

under pressure from increased housing density. Nationwide,

the trend of more people living on the forested landscape

is projected to continue. The number of forested acres per

capita in the United States has been declining and the number

by 2050 is projected to be less than half the 1952 level (Alig

and Butler 2005). Land managers and policy makers will

increasingly need to become involved with issues regarding

the interdependency of socioeconomic trends and changing

landscapes.
24 Interim Update of the 2000 RPA Assessment

Box 7

Measures of stress on ecosystems—Human use

and natural processes combine to determine the

condition of renewable resources. As more people

demand products and services from forest lands and

rangelands, they may stress ecosystem processes that

produce environmental output from them. Hof et al.

(2006) document the current and expected distribution

of the following indicators of forest land and rangeland

condition: Edge of natural land cover, average patch

size of natural land cover, proportion of total exotic

breeding birds, a measure of timber growth on timber

land, a measure of timber mortality on timber land,

a measure of streamflow variation, total nitrogen in

surface waters, total phosphorus in surface waters, and

acidity in precipitation. A specific example involves

exotic birds. Commonly, as resource development

intensifies, the abundance of exotic species that

tolerate human activity increases. Figure 13 shows that

compared with figure 14, the Midwest will continue to have

the highest concentration of exotic breeding birds. Hotspots

for each indicator are defined as the areas in the country with

the highest 10 percent of the values for that indicator.

Interpreting the indicator maps must be done with caution.

The methods used identify only patterns of association

between the condition indicators and explanatory variables,

not cause-effect relationships. Thus, the hotspots should be

viewed only as candidates where ecosystem condition may

erode in the future, suggesting areas for further investigation.

Moving from east to west, the first noteworthy area of

projected hotspot concentration is on the Atlantic seaboard,

running from South Carolina through the North Carolina

piedmont to Massachusetts (fig. 15). The most expansive

concentration of projected hotspots includes a broad area

through the Midwest extending from Ohio in the east, to the

till plains of Iowa and western Nebraska in the west, south

into Kansas, and north into Minnesota and South Dakota.

Three much smaller concentrations appear in Texas, around

the Houston area, the Dallas-Fort Worth area, and in west

Texas around Lubbock and Amarillo. Additional areas with

high concentrations of projected hotspots include the Front

Range of Colorado, the Wasatch Range of Utah, the area

around Las Vegas, and southern California. Additional areas

with two or three projected hotspots are located throughout

the West, the Northeast, Florida, and the large area south of

the Great Lakes States.

Figure 13.—Current condition hotspots for exotic species.

Figure 14.—Predicted hotspots for exotic species in 2025.

Figure 15.—Number of coincident predicted hotspots in 

2025.

0

1

5

6

7

4

3

2

Number

of hotspots

Upper 10 percent

Predicted hotspots
Interim Update of the 2000 RPA Assessment 25

Summary

The U.S. population continues to grow and diversify. Projected

increases in population and income imply increased demands

for all goods and services from U.S. forests and rangelands.

Historical trends suggest that these increased demands will

likely lead to land use changes that can affect the condition

of renewable resources—sometimes permanently. There have

been area changes back and forth between agriculture and forestry. But when areas become developed, they are unlikely to

return to natural vegetation cover or agriculture, although urban

forests can have associated environmental benefits. By 2050,

about 1 acre in 12 may be classed as urban compared with 1 in

32 in 2000. The broader category of developed is projected to

increase from 1 acre in 19 in 1997 to 1 acre in 10 by 2025. Urban and exurban development will affect watersheds, riparian

areas, wildlife habitat, open space, water supplies, and goods

and services desired from forests and rangelands.

The United States population and economy are increasingly

linked to the world population and economy. Each year, the

U.S. population increases by more than 1 million people, in

large part because of immigration. Growth in demand for

energy and raw materials in China and India now have effects

felt around the world. Easing of trade restrictions since World

War II has subjected some sectors of the U.S. economy to new

sources of competition. Manufacturing industries such as steel,

service industries such as data processing and fresh produce in

the agricultural sector have all been affected by trade. These are

examples of structural changes associated with globalization

that influence needs for forest resources. In the forest products

sector, the furniture industry has been reduced by competition

from China, the pulp industry has been affected by decreased

domestic demand and by competition from several sources,

and softwood lumber and oriented strand board imports from

Canada have captured increased market shares in the United

States. Other sources of softwood lumber have also become

more competitive in the U.S. market. Softwood log and chip

exports have declined.

Trade in forest products affects timber harvest in the United

States and thereby affects biodiversity, carbon storage,

and other measures of renewable resource condition, as

well as employment and other economic benefits of forest

management.
26 Interim Update of the 2000 RPA Assessment
Interim Update of the 2000 RPA Assessment 27

The legal, institutional, and economic framework for

sustainable management of renewable resources is largely

determined by ownership of these resources and laws that

govern their use.

Ownership of Forest and Rangelands

In the United States, 57 percent of the forest land is privately

owned (fig. 16). Some 15 percent of the forest land in private

ownership is classed as forest industry and the remainder as

nonindustrial private (Smith et al. 2004). Forest land3 owned

by Native Americans is included in the nonindustrial private

category. The Forest Service is the largest public forest land

management agency with responsibility for 47 percent of the

total forest area in the public ownership category. State (20

percent), U.S. Department of the Interior (DOI) Bureau of Land

Management (BLM) (14 percent), and County and Municipal

(3 percent) are other ownership categories delineated by the

data. The other public category includes 16 percent of the forest

land in public ownership and includes lands managed by the

DOI National Park Service (NPS), Department of Defense,

Department of Energy, and all other Federal ownerships.

Forest land in the various ownership categories is not evenly

distributed across the country. Some 54 percent of the forest

land in the forest industry category is located in the South.

About 73 percent of the forest land in the nonindustrial

category is located in the East (fig. 17). About 44 percent of

the forest land in the State category is located in Alaska and

32 percent is in the North. Nearly two-thirds of the county

and municipal lands are in the North. About 86 percent of

the forest land managed by Federal agencies is located in the

West. About 79 percent of the publicly owned forest land is

in the West and 74 percent of the privately owned forest land

is in the East. The location and ownership of forest land tends

to determine the focus of management issues, which differ by

type of ownership.

Some 66 percent of the rangeland area is in non-Federal ownerships (table 3). About 61 percent of the rangeland in non-Federal ownership is in the Rocky Mountain region, 30 percent is

in the South, about 9 percent is in the Pacific Coast region, and

a small amount is in the North. Most of the rangeland within

the NFS is in the West as is all of the rangeland managed by

the BLM. The BLM manages 27 percent of the rangeland in the

conterminous States and the Forest Service, 7 percent.

Figure 16.—U.S. forest land by ownership.

3 Lands held in trust by the United States or States for Indian tribes or individual Indians or lands owned in fee simple by Indian tribes whether subject to

Federal or State restrictions against alienation or not.

Figure 17.—Distribution of forest land in the private 

nonindustrial ownership.

Legal, Institutional, and Economic Framework for Forest and Rangeland 

Conservation and Sustainable Management
28 Interim Update of the 2000 RPA Assessment

The Privately Owned Forest and Rangeland 

Estate

About 57 percent, or 430 million acres, of forest land in the

50 States is privately owned. Forest industry accounted for

an estimated 66 million acres in 2002. The forest industry

ownership units are associated with timber processing

facilities; however, millions of acres in the forest industry

ownership have been sold to timber investment management

organizations, real estate investment trusts, or other entities

that do not own processing facilities. We expect the number

of acres in the forest industry category to decline as new forest

inventories are reported.

Other private owners include other businesses or corporations,

partnerships, tribes, families, and individuals. Family forests

include lands that are at least 1 acre in size, 10 percent stocked,

and owned by individuals, married couples, family estates and

trusts, or other groups of individuals who are not incorporated

or otherwise associated as a legal entity (Butler and

Leatherberry 2004). An estimated 10.3 million family forest

owners in the conterminous States control 262 million acres of

forest land. An increasing number of family forest owners own

smaller size tracts of forest land. The number of family forest

owners in the conterminous United States increased by 11

percent between 1993 and 2003. Most of this increase occurred

among owners with fewer than 50 acres of forest land (fig. 18).

Private ownerships are managed with a variety of objectives.

For family forest owners, the most common reasons cited as

very important or important for ownership are to enjoy beauty/

scenery, to protect nature and biological diversity, that the

acreage is part of a farm or home site, for privacy, and to pass

the land on to heirs.

Twenty percent of the forest land in family control is owned

by people 75 years or older. Because of the advanced age of

many owners and their stated intentions for their land, land

transfers will be substantial during the next 10 to 20 years with

implications for changes in management objectives as a new

generation of forest landowners takes over.

Regulations affecting privately owned forest land vary by State

and locality. Forty-four States have best management practice

legislation that has the intent of promoting better management

of lands, when timber production is involved, especially

to protect water quality (Ellefson et al. 1995). Nine States

have forest practice regulatory acts that have the intent of

promoting good management practices and may require plans,

reforestation, and other actions on the part of the landowner.

Table 3.—Rangeland area in the conterminous States by ownership and region in 1997 (1,000 acres).

Ownership

Region Non-Federal National forests BLM Total

Pacific Coast 32,757 10,813 22,504 66,074

Rocky Mountain 229,117 29,785 132,903 391,805

South 112,770 0 0 112,770

North 98 65 0 163

Total 374,742 40,663 155,407 570,812

Figure 18.—Number of owners by size of holdings (acres).

BLM = Bureau of Land Management
Interim Update of the 2000 RPA Assessment 29

The Federal Government, as well as some State and local

jurisdictions may offer incentives and/or technical assistance to

private landowners to encourage better management of private

lands. Such programs of the Forest Service include cost sharing

for tree planting and other forest management activities and

assistance in development of management plans. The USDA

Cooperative State Research, Education, and Extension Service

provides technical advice and assistance to private forest

landowners. Some States provide assistance in management

and may give forest land preferential tax treatment. Localities

may offer tax incentives to keep land in forests. Income from

forest land is subject to Federal taxes as well as State and local

taxes as tax codes specify.

Private property rights have their origins in part with the

Magna Carta (National Research Council 1997). Governments

at all levels may take private property if in the public interest.

The public interest is refined over time to reflect changing

social values. For example, private property rights within the

context of the Endangered Species Act of 1973 are currently

being litigated in the courts.

The Publicly Owned Forest and Rangeland 

Estate

Management of Federal lands is influenced by Federal

legislation as interpreted by the judiciary and as administered

by the executive branch of government. The BLM manages the

largest area of combined Federal land and water area (fig. 19).

Changes in social values may lead to changes in management

practices that are initiated by one or more branches of

government. For example, the National Environmental

Policy Act of 1969 requires that Federal agencies prepare an

environmental impact statement for major actions affecting

the quality of the human environment. This act facilitated

public scrutiny of management of Federal forest land and

associated resources. For the Forest Service, the Forest and

Rangeland Renewable Resources Planning Act, as amended,

further facilitated public involvement in management of

renewable resources. Other Federal agencies have varying

legislative mandates for management and public review of this

management.

State, county, and municipal governments own nearly 73 million

acres of the Nation’s forest land, with most of these lands in

the Great Lake States (Minnesota, Wisconsin, and Michigan),

Alaska, New York, Oregon, Pennsylvania, and New York. The

largest single State ownership of 27 million acres is in Alaska.

State and county forests often have an economic development

focus and thus have proven to be especially important to

local and regional economies. Government programs that

foster stability in community income and employment have

proven to be especially important in accomplishing economic

development (National Research Council 1997).

Management of and Access to Inland Water

About 7 percent, or 161 million acres, of the United States

is covered by water. In the United States, the two water

right doctrines are appropriation and riparian. The law of

appropriation, developed by miners and farmers in the West to

meet their needs, has two basic tenets: (1) a water right can be

acquired by the party diverting the water from the water course

and applying it to a beneficial use, and (2) the earliest water

right will have priority over other, later-acquired rights.

Although most States in the West now recognize various

instream-flow water rights (Gillian and Brown 1997), they

often place many restrictions on who can hold them, the uses

of the water, and the degree of proof to support them. Almost

none allow the Forest Service to hold an instream flow right.

Figure 19.—Distribution of land and water area among 

Federal land-managing agencies.
30 Interim Update of the 2000 RPA Assessment

East of the 100th meridian, the doctrine of riparian rights

entitles riparian landowners to reasonable use of streamflow as

long as they obtain a permit from the State first. Over the past

few decades, the riparian doctrine has been modified to more

closely resemble the appropriation doctrine. The number of

waterbodies with diminished streamflows is growing rapidly in

the East.

Access rights for recreational use of water are also difficult

to describe. In general, trespass laws apply to land adjoining

water, and private owners can deny access. Once access has

been achieved, however, water can generally be used for

recreation despite the existence of adjacent, posted land.

The 191 million acres of NFS lands contain 128,000 miles of

fishable streams and rivers, more than 2.2 million acres of lakes,

ponds, and reservoirs, and 12,500 miles of coast and shoreline.

Management of and Access to Minerals

The Nation’s forest lands and rangelands are underlain by

extensive mineral resources. The greatest concentrations occur

in the western mountain ranges, the Western Overthrust Belt,

the Northern Great Plains, and the Appalachian region.

Ownership patterns for energy and mineral resources do not

necessarily match surface ownership patterns because mineral

rights may be severed from the surface. Privately held minerals

underlie private, as well as public, lands. Similarly, publicly

held mineral rights exist under both public and private lands.

Significant undiscovered energy and mineral resources in the

Western United States are publicly held. In the East, minerals

are predominately privately held, although some areas with

high mineral potential reside in the public estate.

The Mining Law of 1872 governs mineral locations on public

domain lands (lands which have never left the Federal estate)

for most nonenergy minerals. The law was framed to encourage

mineral exploration and development by individuals or firms.

If a deposit is discovered, it may be claimed and extracted to

exhaustion by the finder. A deposit that can be shown to be

economic may be patented, thus transferring the surface and

mineral rights to private ownership. The rights to both claims

and patented claims may be sold or transferred.

The Mineral Leasing Act of 1920 and its amendments govern

the location and extraction of energy and some industrial

minerals. Nonenergy minerals on acquired lands, which would

otherwise be subject to the Mining Law of 1872, are covered

by the Mineral Leasing Act. This law, too, was intended

to encourage mining activities. Individuals and firms may

explore the public lands; however, discovery does not lead to

a transfer of ownership. Mineral locations are leased, with the

lessor having an exclusive right to extract the deposit ore to

exhaustion. Royalties are paid to the Government, based on the

value of energy or mineral resource extracted.

Economic Institutions

Markets—Within U.S. economic institutions, the production

and consumption of natural resources are governed by a

number of factors, with competitive market forces being

especially important for resources coming from private lands

and from imported materials.

Markets for processed wood products are generally recognized

as being competitive with producers and consumers responding

to prices in expected ways. Markets for roundwood can be

more or less competitive depending on the numbers of buyers

and sellers in local situations. Depending on the product,

local markets may be affected by international markets.

Characteristics of markets for other renewable resources vary,

depending on the resource and ownership. In some areas of

the country, markets have developed for water rights, forage,

various types of recreation including wildlife viewing, and

mineral rights. For the most part, these markets have developed

for renewable resources on private lands. Timber is also sold

at fair market value on many public ownerships. The sale of

the rights to use other renewable resources on public lands

may involve a mixture of market information and legislative

oversight or it may be provided free as is the case for recreation

on many public ownerships.
Interim Update of the 2000 RPA Assessment 31

Markets for minerals have much variation. Each mineral

possesses characteristic physical properties that determine uses

and, ultimately, markets for them. Metallic minerals typically

occur in one of several types of mineralogical compounds.

They are seldom traded at this raw stage, however. Instead,

milling, smelting, and refining are used to separate the metal

from other elements or compounds present in the ore. The

metals are then sold in pure or near pure form, with any unit

replaceable by and identical to any other, regardless of origin.

Transportation costs aside, each unit sells for the same price.

This degree of competition is not necessarily present in gaining

access to minerals on public lands.

Water markets are emerging in many regions of the United

States. Water prices are highly variable across regions and

within local areas of the same region. Most activity in water

markets has occurred in the Western United States, where

the amount of water annually transferred through leases is

more than 50 times greater than the amount transferred as

water rights. On an annual basis, however, the price of water

transferred as rights significantly exceeds the price of water

transferred in leases. The median price of leases is greatest in

Arizona, California, New Mexico, and Nevada. The median

price of water rights is greatest in Colorado and Nevada.

Combining across leases and annualized water rights, the

highest medians for municipal purposes (above $85 per acrefoot per year) are found in California, Colorado, and Nevada

and the lowest medians (below $30) are found in Texas and

Utah; the highest median price for irrigation purposes (above

$75) is found in Colorado and the lowest medians (below $10)

are for Idaho, Oregon, Utah, and Wyoming; and the highest

median for environmental purposes (above $60) is found

in California and the lowest medians (below $25) are for

Colorado and Idaho.

The use of market mechanisms is also evolving to maintain or

enhance the production of ecosystem services from forest lands

and rangelands. (See boxes 8 and 9 for defining ecosystem

services and valuing them). Appropriate roles of markets

and/or market-based approaches in influencing the supply of

and demand for ecosystem services are still being defined.

Market-based approaches, such as “cap and trade” systems

and pollution taxes, have been used as an efficient way to

implement environmental regulations. For example, the “cap

and trade” system has been used in the United States to meet

sulfur dioxide emission targets. Pollution taxes, which charge

per ton of pollutant produced, create similar market incentives

but are not necessarily linked to pollutant reduction targets.

Incentives—The United States has a long history of using

incentive programs to accomplish environmental goals.

For example, the Conservation Reserve Program provides

incentives for farmers to take highly erodible cropland out

of production, resulting in improvements in water quality as

one of several benefits. Tree-planting subsidies for timber

production in the South have a long and successful history.

Market-based incentives are being considered to encourage the

maintenance and enhancement of ecosystem services, in effect,

encouraging the production of environmental “goods” rather

than controlling environmental “bads.” Programs specifically

designed to enhance the production of services such as

carbon sequestration, water and air quality, and biodiversity

conservation are newer and their impacts uncertain.
32 Interim Update of the 2000 RPA Assessment

Box 8

What are ecosystem services?—There is no commonly

accepted or “correct” definition of ecosystem services. An

often cited definition from Daily (1997) defines ecosystem

services as the “conditions and processes through which

natural ecosystems, and the species that make them up,

sustain and fulfill human life.” The Millennium Ecosystem

Assessment (World Resources Institute 2003) defined four

categories of ecosystem services: provisioning services

include all products from ecosystems, regulation services

include benefits from ecosystem processes, cultural services

include all nonmarket benefits obtained from ecosystems,

and supporting services include ecosystem functions. Boyd

and Bahnzaf (2005) defined ecosystem services as “end

products of nature that yield human well-being.” Although

no one disputes that ecosystems provide a variety of services

to society, understanding is limited about the processes that

result in services and how humans value those services.

The Daily definition is broad and comprehensive,

recognizing the interconnectedness of human and natural

systems. The Millennium Ecosystem Assessment categories

of services are also comprehensive, with some separation

between ecosystem function and services across the four

categories. The Boyd and Bahnzaf definition focuses on

separating ecosystem services from ecosystem processes,

functions, and benefits. For example, the Daily and

Millennium Ecosystem Assessment definitions would

include water purification, aesthetic beauty, and nutrient

recycling as ecosystem services, although Boyd and Bahnzaf

would categorize water purification as an ecosystem function

(providing clean water as a service); and aesthetic beauty

as an ecosystem benefit (based on an ecosystem service of

landscape arrangement).

Separating processes from their services and benefits is

particularly important for evaluating management and policy

options. Biophysical scientists provide the understanding

of how nature physically “produces” the services that are

essential for society, and how human or natural disturbances

alter service flows. Economists can then assess the value of

changes in the service flows.

Box 9

What are ecosystem services worth?—It’s a simple question with no simple answer. The National Research Council

(2005) recently reviewed the state-of-the-art for valuing

ecosystem services. The report recognized the importance of

valuing ecosystem services for informing policy decisions,

and also recognized the significant challenges:

The fundamental challenge of valuing ecosystem services lies in providing an explicit description and adequate assessments of links between the structures and

functions of natural systems and the benefits derived by

humanity (National Research Council 2005: 29).

Urban forests have been recognized for providing a

number of ecosystem services that improve environmental

quality and human health. The Urban Forest Effects model

(UFORE) was developed to model ecological processes and

functions to estimate the effects of urban forests on services

such as carbon sequestration and improved air quality

(Nowak and Crane 2002). The UFORE model was used

to estimate that urban forests nationally store between 335

and 980 million metric tons of carbon, sequester between

14.7 and 27.7 million metric tons per year (Nowak and

Crane 2002), and remove 711,000 metric tons per year of

air pollutants (Nowak et al. 2002). Valuing these services

is more problematic since the appropriate value for an

application is often both site and context specific. Nowak

and Crane (2002) applied an estimate of the marginal social

cost of carbon dioxide emissions of $20.30 per ton of carbon

(Fankhauser 1994). Carbon markets in the United States
Interim Update of the 2000 RPA Assessment 33

Box 9 (continued)

are developing, and may be a basis for estimating the total

value of the storage and sequestration services in the future.

The Chicago Climate Exchange has an increasing volume of

trade, with prices per metric ton of CO2 reaching $2.75 per

metric ton in March 2006 (Chicago Climate Exchange 2006).

Prices on the European Carbon Exchange are considerably

higher as a result of the Kyoto Protocol. European prices

ranged between 25 and 30 euros through most of 2006,

although prices dropped sharply at the end of April to about

17 euros (European Climate Exchange 2006)

The National Research Council report reviewed numerous

ecosystem valuation case studies. Since most ecosystem

services are public goods, nonmarket valuation methods

are typically employed. Another approach that has been

applied in a number of cases is the “replacement cost” or

“avoided cost” approach, which can be an effective way to

evaluate whether maintaining the service through resource

management is more cost effective than some technological

option (e.g., protecting watersheds for New York City rather

than build new water treatment facilities), but this approach

does not value the ecosystem service itself. Significant

challenges remain, but progress has been made both in

understanding the ecological processes and functions and in

valuing the resulting services.

Research Institutions

Natural resources research in the United States is primarily

supported by the Federal Government and, to a lesser extent, by

State agencies, private foundations, and businesses. Research

takes place in Federal institutions, State institutions such

as universities, and private organizations such as research

institutes and industry. Our ability to manage forest lands and

rangelands depends largely on our understanding of forest

land and rangeland dynamics and our ability to predict the

consequences of management actions and natural and human

disturbance. Our capacity to implement research depends on

investments in research and fostering access to this research by

stakeholders and policymakers.

Historically, research pertaining to rangelands has emphasized

ecological and grazing-related problems. Within the socioeconomic research area, studies have primarily dealt with tradeoffs

derived from different management practices. Little work has

taken place that integrates ecosystem and economic processes

to better understand the contribution of rangelands in providing

ecosystem services and other measures of human well-being.

Availability and Extent of Data for Measuring 

Indicators of Sustainable Resource 

Management

Minerals—The Sustainable Minerals Roundtable developed

87 indicators of sustainability for energy and mineral systems.

Thirty-eight of the indicators were given priority. The First

Approximation Report of the Sustainable Minerals Roundtable

lists the indicators, discusses the process used to develop criteria and indicators, and offers complete write-ups for a small

number of indicators (Sustainable Minerals Roundtable 2003).

Water—A preliminary report by the Water Resources

Roundtable discusses the roles of indicators, conceptual

foundations for the work of the roundtable, and criteria and

indicators on the sustainability of water resources (Water

Resources Roundtable 2005). The report presents findings

for 17 indicators selected from a candidate list of 386. Data

availability and quality varied across the selected indicators.

Rangelands—The Sustainable Rangelands Roundtable

(SRR) has developed 64 indicators of rangeland sustainable

management at regional and national scales (Sustainable

Rangelands Roundtable n.d.). A summary of data availability,
34 Interim Update of the 2000 RPA Assessment

as indexed using four categories based upon the existence of

standardized measurement procedures and the accessibility

of actual data sets, is presented for these indicators in table 4.

Recognizing the technical, legal, and monetary hurdles to

monitoring all 64 indicators, the SRR also reached a consensus

on 27 core indicators that warrant more immediate attention

by Federal agencies. These core indicators are underlined in

table 4. Only 4 out of the 13 ecological indicators and 6 out

of 14 socioeconomic indicators presently are populated with

regional-level or national-level data sets based upon broadly

accepted methodologies. Thus, serious challenges remain

if a broad suite of indicators for monitoring the sustainable

management of rangelands is to be widely accepted and

used. One of the largest obstacles to monitoring biophysical

indicators is the lack of consistent, comprehensive data sets on

Federal rangelands.

Forests—Analysis of trends in resource condition as revealed

by measurement of indicators requires the availability of data

on a continuing basis. When the desire for scaling up and

down from national to regional to local scales is considered,

data must be available for the Nation as a whole through

Table 4.—Categorized availability of data for 64 sustainable rangeland roundtable indicators.

Indicator Availability

of data sets1

Criterion 1: Conservation and maintenance of soil and water resources of rangelands

1. Area and percent of rangeland with significantly diminished soil organic matter and/or high carbon:nitrogen ratio D

2. Area and extent of rangelands with changes in soil aggregate stability B

3. Assessment of microbial activity in rangeland soils D

4. Area and percent of rangeland with a significant change in extent of bare ground C

5. Area and percent of rangeland with accelerated soil erosion by water and wind B

6. Percent of water bodies in rangeland areas with significant changes in natural biotic assemblage composition A

7. Percent of surface water on rangeland areas with significant deterioration of their chemical, physical, and biological 

properties from acceptable levels A

8. Changes in groundwater systems A

9. Changes in the frequency and duration of surface no-flow periods in rangeland streams A

10. Percent stream miles in rangeland catchments in which stream channel geometry significantly deviates from the 

natural channel geometry B

Criterion 2: Conservation and maintenance of plant and animal resources on rangelands

1. Extent of land area in rangeland B

2. Rangeland area by vegetation community C

3. Number and extent of wetlands A

4. Fragmentation of rangeland and rangeland vegetation communities C

5. Density of roads and human structures A

6. Integrity of natural fire regimes on rangeland C

7. Extent and condition of riparian systems C

8. Area of infestation and presence/absence of invasive and nonnative plant species of concern C

9. Number and distribution of species and communities of concern A

10. Population status and geographic range of rangeland-dependent species B

Criterion 3: Maintenance of productive capacity on rangeland ecosystems

1. Rangeland above ground phytomass A

2. Rangeland annual productivity A

3. Percent of available rangeland grazed by livestock D

4. Number of domestic livestock on rangeland B

5. Presence and density of wildlife functional groups on rangeland C

6. Annual removal of native hay and nonforage plant materials, landscaping materials, edible and medicinal plants, 

wood products, and native hay D
Interim Update of the 2000 RPA Assessment 35

Table 4.—Categorized availability of data for 64 sustainable rangeland roundtable indicators (continued).

1

 Availability of data sets is categorized by: A—methods and procedures for data collecting and reporting, and data sets of useable quality exist at the regionalnational level; B—standardized methods and procedures for data collecting and reporting exist at the regional-national level, but useable data set(s) do not exist 

at the regional-national level; C—some data set(s) exist at the regional-national level, but methods and procedures are not standardized at the regional-national 

level; D—conceptually feasible or initially promising, but no regional-national methods, procedures, or data sets currently exist.

Criterion 4: Maintenance and enhancement of multiple economic and social benefits to current and future generations

1. Value of forage harvested from rangeland by livestock A

2. Value of production of nonlivestock products produced from rangeland D

3. Number of visitor days by activity and recreational land class C

4. Reported threats to quality of recreation experiences B

5. Value of investments in rangeland, rangeland improvements, and recreation/tourism infrastructure D

6. Rate of return on investment for range livestock enterprises B

7. Area of rangelands under conservation ownership or control by conservation organizations B

8. Expenditures (monetary and in-kind) to restoration activities D

9. The threat or pressure on the integrity of cultural and spiritual resource values D

10. Poverty rate—general A

11. Poverty rate—children A

12. Income equality A

13. Index of social structure quality C

14. Community satisfaction A

15. Federal transfers by categories (individual, infrastructure, agriculture, etc.) A

16. Presence and tenure of natural resource nongovernmental organizations at the local level D

17. Sources of income and level of dependence on livestock production for household income C

18. Employment diversity A

19. Agriculture (farm/ranch) structure A

20. Years of education A

21. Value produced by agriculture and recreation industries as percent of total A

22. Employment, unemployment, underemployment, and discouraged workers by industrial sector A

23. Land tenure, land use, and ownership patterns by size classes C

24. Population pyramid and population change A

25. Income differentials from migration A

26. Length of residence (native, immigrant more than 5 yrs., less than 5 yrs.) A

27. Income by work location versus residence A

28. Public beliefs, attitudes, and behavioral intentions toward natural resources C

Criterion 5: Legal, institutional, and economic framework for rangeland conservation and sustainable management

1. Land law and property rights B

2. Institutions and organizations D

3. Economic policies and practices C

4. Public information and public participation C

5. Professional education and technical assistance C

6. Land management D

7. Land planning, assessment, and policy review C

8. Protection of special values C

9. Measuring and monitoring C

10. Research and development C

Indicator Availability 

of data sets1
36 Interim Update of the 2000 RPA Assessment

comprehensive monitoring programs. Within the forestry

sector, the comprehensive monitoring programs are the Forest

Inventory and Analysis Program of the Forest Service and

the Natural Resources Inventory of the NRCS. The Census

Bureau provides locally, regionally, and nationally consistent

data for some measures of the forest products industries. Trade

associations such as the American Forest and Paper Association

provide some data on capacity and production for some

industries such as pulp and paper. Measures of participation

and other attributes of recreation are provided on a continuing

basis and are consistent locally, regionally, and nationally

(Cordell et al. 2004).

The Forest Service (2004) reviewed the 67 indicators developed

in the Montreal Process and found that data was generally complete nationally, current, and reliable for eight indicators—six

based on the Forest Service Forest Inventory and Analysis Program and two based on Census Bureau data (fig. 20).

Localizing information from higher scale data—Local,

regional, and national assessments are conducted at different

scales but use the same basic measures of resource condition.

In some cases, data sets can be aggregated from local to

national scale. For example, the Forest Inventory and Analysis

program conducts samples to gather detailed local timber

Figure 20.—Capacity to measure and monitor changes in the 67 indicators from the Montreal Process.

Criterion Indicators Data status

Coverage Currency Frequency

1 Conservation 

of biodiversity

1 Area of total land and forest land by type

2 Area of forest by type and age

3 Area of forest by type and IUCN category

4 Area of forest by type, age, and IUCN

5 Fragmentation by forest type

6 Number of forest-dependent species

7 Status of forest-dependent species

8 Number of forest-dependent species in restricted range

9 Population levels of representative species

2 Maintenance 

of productive 

capacity 

of forest 

ecosystems

10 Area of forest land & timber land available for timber production

11 All live and growing stock volume

12 Area and growing stock in plantations

13 Annual removals for products vs. sustainable volume

14 Removals of nontimber products vs. sustainable levels

3 Maintenance of 

forest 

ecosystem

health and 

vitality

15 Area and percent forest damaged by insect, disease, fire, flood, etc

16 Area and percent forest affected by airbourne agents (nitrate, ozone, etc.)

17 Area and percent forest with diminished biological components

4 Conservation 

and 

maintenance of 

soil and water 

resources

18 Area and percent of forest with significant soil erosion

19 Area and percent of forest managed primarily for protective functions

20 Percent of stream kilometers in forested catchments

21 Area and percent of forest with significantly diminished soil organic matter

22 Area and percent of forest with significant soil compaction

23 Percent of water bodies in forested areas with significant change in 

biodiversity

24 Percent of water bodies in forested areas with significant change in hydro. 

character

25 Area and percent of forest area experiencing significant accumulation of toxic 

substances

5 Maintenance of 

forest 

contribution

to global 

carbon cycles

26 Total forest biomass and carbon pool by type and age

27 Contribution of forest to total global carbon budget

28 Contribution of forest products to global carbon budget indicators
Interim Update of the 2000 RPA Assessment 37

Criterion Indicators Data status

Coverage Currency Frequency

Figure 20.—Capacity to measure and monitor changes in the 67 indicators from the Montreal Process (continued).

6 Maintenance 

and 

enhancement 

of long-term 

multiple 

socioeconomic

benefits to 

meet the needs 

of societies

29 Value and volume of wood products (including value added)

30 Value and quantity of nonwood forest products

31 Supply and consumption of wood/wood products (including per capita)

32 Value of wood and nonwood forest products as percent of GDP

33 Degree of recycling of forest products

34 Supply and consumption/use of nonwood products

35 Area and percent forest land managed for recreation (rel. to total)

36 Number and type of recreation facilities (rel. to forest area and population)

37 Number of recreation visitor days (rel. to forest area and population)

38 Value of investment in forest growth, health, management, recreation, etc.

39 Expenditures on research and education

40 Extension and use of new and improved technology

41 Rates of return on investment

42 Area and percent forest managed to protect cultural needs

43 Nonconsumptive forest use values

44 Direct and indirect employment in forest sector (rel. to total)

45 Average wage rates and injury rates in forest sector

46 Viability and adaptability to change of forest-dependent communities

47 Area and percent of forest land used for subsistence purposes

7 Legal, 

institutional, 

and economic 

framework 

for forest 

conservation 

and 

sustainable 

management 

48 Clarifies property rights

49 Provides for periodic forest-related planning, assessment, and policy review

50 Provides opportunities for public participation in public policy and 

decisionmaking 

51 Encourages best practice codes for forest management

52 Provides for the management of forests to conserve special environmental 

values

53 Provide for public involvement activities and public education, etc.

54 Undertake and implement periodic forest-related planning, assessment, etc.

55 Develop and maintain human resource skills across relevant disciplines

56 Develop and maintain efficient physical infrastructure to facilitate the supply of 

forest products and services

57 Enforce laws, regulations, and guidelines

58 Investment and taxation policies and a regulatory environment which 

recognizes the long-term nature of investments 

59 Nondiscriminatory trade policies for forest products

60 Availability and extent of up-to-date data, statistics, and other information

61 Scope, frequency, and statistical reliability of forest inventories, etc.

62 Compatibility with other countries in measuring, monitoring, and reporting 

63 Development of scientific understanding of forest ecosystems

64 Development of methodologies to measure and integrate environmental and 

social costs and benefits into markets and public policies

65 New technologies and the capacity to assess socioeconomic consequences 

66 Enhancement of ability to predict impacts of human intervention on forests

67 Ability to predict impacts on forests of possible climate change

KEY

Notes on the rating system: This rating provides a general overview of the data supporting the indicators. Green means few gaps, 

yellow means several gaps, red means no data or numerous gaps, and purple indicates data that has been modelled.

Data 

coverage

Data 

currency

Data 

frequency

Data generally complete nationally, current, and reliable. National 1997+ Annual to 

< 5-year 

periodic

Data may not be consistent nationally, slightly dated, and not measured 

frequently enough.

Regional 

or some 

national

1980–96 5+ year 

periodic

Data are from inconsistent sources or nonexistent, more than 15 years old 

or partial, and have no consistent plan for remeasurement.

Varies or 

incomplete

Incomplete One-time or 

incomplete

Data are modelled (currency and frequency dots refer to model baseline data). Modelled
38 Interim Update of the 2000 RPA Assessment

inventory data that can be statistically aggregated to larger

geographic and thematic scales. Other types of measurements

are not amenable to sampling, and must instead be made at

regional scale, and then disaggregated for local assessments.

To illustrate one application of national assessment data at local

scale, we used local scale land-cover maps to disaggregate

national measures of forest fragmentation.

The national assessment protocols (Riitters et al. 2002)

identified forest parcels as dominant (i.e., surrounded by 60

percent forest), interior (90 percent), and core (100 percent).

The protocols for localizing the information (Riitters et al.

2003) disaggregate the national statistics according to forest

type as identified by State-level maps from the GAP Analysis

Program in Oregon and New York. The GAP maps were

overlaid on the national fragmentation maps to assign a forest

type to the fragmentation category measured in the national

analysis.

Because fragmentation varies in meaningful ways with the size

of the surrounding neighborhood, the results are shown for

three neighborhood sizes of 2.25 hectares, 65.61 hectares, and

5314.41 hectares (5.56, 150, and 13,130 acres, respectively)

(fig. 21). Typically, the proportions of core and interior forest

decrease with increasing neighborhood size, indicating that

most forests are fragmented to some degree. At the same time,

the proportion of dominant forest decreases less rapidly with

increasing neighborhood size, indicating that forest tends to be

the dominant land cover type where it occurs. For a given combination of neighborhood size and fragmentation category, the

differences among forest types (New York) or forest vegetation

classes (Oregon) reflect local differences in overall forest fragmentation influencing locally defined forest types. Comparisons

among neighborhood sizes or fragmentation categories can

be interpreted with respect to spatial scales and intensities at

which local fragmentation occurs (Riitters et al. 2003).
Interim Update of the 2000 RPA Assessment 39

Figure 21.—Localizing information from higher scale data. Forest land fragmentation statistics for selected forest types in 

Oregon (A) and New York (B). The proportions of total area of each type meeting national criteria for “core” ( ), “interior” 

(r), and “dominant” ( ) forest land are shown for landscape sizes of 2.25 hectares (ha), 65.61 ha, and 5,314.41 ha. The 

forest types have been sorted according to the proportion of “interior” for each landscape size. Adapted from Riitters et al. 

(2003).

(A)
40 Interim Update of the 2000 RPA Assessment

Figure 21.—Localizing information from higher scale data. Forest land fragmentation statistics for selected forest types in 

Oregon (A) and New York (B). The proportions of total area of each type meeting national criteria for “core” ( ), “interior” 

(r), and “dominant” ( ) forest land are shown for landscape sizes of 2.25 hectares (ha), 65.61 ha, and 5,314.41 ha. The 

forest types have been sorted according to the proportion of “interior” for each landscape size. Adapted from Riitters et al. 

(2003) (continued).

(B)
Interim Update of the 2000 RPA Assessment 41

Summary

More than one-half (57 percent) of the forest land in the United

States is privately owned and 85 percent of this land is in

nonindustrial private ownership. Nonindustrial private forest

land owners have a variety of ownership objectives. Because

of the advancing age of people in this ownership category,

a significant percentage of U.S. forest land will change

ownership over the next 20 years with implications for possible

changes in objectives. The number of forest owners continues

to increase with consequent parcelization of the landscape. The

decreasing average size of forest ownerships has implications

for ownership objectives and delivery of services such as

protection from wildfire.

The sale of millions of acres of forest land owned by forest

industry to timber investment management organizations, real

estate investment trusts, and other private ownership entities

adds uncertainty to the future management and disposition of

these lands. Available information suggests that, for now, some

purchasers of forest industry lands may develop or sell lands

with high residential value, but keep most of the ownership

intact. The sale of forest industry lands is expected to continue

(Clutter et al. 2005).

The publicly owned forest estate amounts to 43 percent of the

total forest land area. Federal lands account for 77 percent of

the publicly owned forest land. Changes in social values may

lead to changes in management practices that are initiated by

one or more branches of government. For example, timber

harvest on national forests peaked at 12.7 billion board feet in

1987 and declined to 2 billion board feet in 2004, reflecting

concern about threatened and endangered species and other

values. State and county forests are managed with a variety of

objectives.

Whether public or private, forest management with timber

production as an objective is linked to global markets. The

expected modest increases in stumpage prices in the next

several decades weaken expected returns for implementing

some management practices.

On all ownerships, ecosystem services have long been

recognized as coproducts of forest land and rangeland

ownership. If markets could be further developed for

these products, forestry as a land use would become more

competitive relative to other land uses. Markets for water are

developing in the West and interest in markets for carbon

storage is increasing. Some markets, such as leasing forest land

for hunting, have been around for decades. Ecosystem services

provided by urban forests for air pollution removal and carbon

storage are valued in the billions of dollars per year.

Within the existing legal, institutional, and economic

framework for forest land and rangeland conservation and

management, lack of data for monitoring the condition

of renewable resources at a national scale is apparent for

minerals, water, range, and forests. This assessment of data

availability was done within the context of the Montreal

Process framework, but the issue is also more generally

recognized (H. John Heinz III Center for Science, Economics,

and the Environment 2002, 2006; United States Environmental

Protection Agency 2003). We demonstrate one way to localize

some information from higher scale data. The development

of consistent local, regional, and national scale data for the

indicators in the Montreal Process, however, is challenging in

developing a statement about sustainable forest management in

the United States.
42 Interim Update of the 2000 RPA Assessment
Interim Update of the 2000 RPA Assessment 43

Figure 22.—Forest land area.

Conservation of Biological Diversity

Figure 23.—Unreserved forest land in the East by forest 

type group: 1977 and 2002.

Figure 24.—Unreserved forest land in the West by forest 

type group: 1977 and 2002.

Area of Timber Land by Forest Type

Between 1977 and 2002 in the Eastern States, the area of

spruce-fir, white-red-jack pine, oak-gum-cypress, oak-hickory,

and maple-beech-birch increased (fig. 23). During this same

time period in the Western States, the area of Douglas-fir, firspruce, other softwoods, and western hardwoods also increased

(fig. 24).

Between 1977 and 2002, the area of longleaf-slash pine, oakpine, elm-ash-cottonwood, and aspen-birch declined in the

Eastern States. In the West, the area of ponderosa pine, western

Biodiversity enables the ecosystem to respond to external

influences, to recover after disturbance, and to maintain the

organisms essential for its ecological processes. Human

activities can adversely impact biodiversity by altering habitats,

introducing invasive species, or reducing the population or

ranges of species. Conserving the diversity of organisms should

support the ability of ecosystems to function, reproduce, and

remain productive.

Historical Trends in Forest Land Cover

At the time of arrival of European immigrants around 1630,

the total area of forest land in the United States is estimated to

have been 1,045 million acres (fig. 22) (Smith et al. 2004). This

acreage represented about 46 percent of the total land area. The

area of forest land declined steadily as settlement proceeded, to

an estimated 759 million acres in 1907 or 33 percent of the total

land area. Forest area has been relatively stable since the 1920s,

and in 2002, the area amounted to 749 million acres. Stability

in total land area does not mean that no change in forest land

area has occurred. There have been shifts from agriculture to

forests and vice versa. Some forest land has been converted to

more intensive uses such as urban land. Even on areas where

the area of forest land has remained stable, changes occur as

forests respond to human manipulation, aging of the forest, and

other natural processes.
44 Interim Update of the 2000 RPA Assessment

white pine, hemlock-Sitka spruce, larch, and lodgepole pine

decreased during the same time period.

In the Eastern States, forests are getting older as represented

by the increase in the area of forest types that are more

representative of later stages of succession, and by the decrease

in the area of forest types that are more representative of earlier

successional stages. Increases in earlier successional forest

types, such as cottonwood, birch, and poplar, reflect either new

forest land or forest land that was harvested to the point where

a completely new stand was established.

Natural processes will continue to result in changes in the area

of forest types even if the total area of forest land remains

constant. For example, without human intervention, the area

of the aspen-birch forest type will continue to decline. Human

intervention has caused the loss of area of forest types such as

slash pine. Even as forests age, duplication of pre-European

conditions are not possible. For example, the ravages of the

exotic chestnut blight forever changed the nature of forest

ecosystems in the East.

Forest cover projections differ markedly by region, owner,

and forest cover type (Alig and Butler 2004a). Although some

regions such as the North are projected to have relatively small

percentage changes by 2050 in common types such as maplebeech-birch (less than 5 percent), others in the South have

relatively large projected changes: Projected changes include

reductions of 19 percent for upland hardwood on nonindustrial

private forest timber lands and 58 percent on forest industry

timber lands in the South Central region and increases in excess

of 25 percent for planted pine for both private ownerships

in the South. Although the area of softwoods is projected to

increase across many regions of the country, especially on

forest industry lands, hardwoods will remain the dominant

forest type on private lands.

Projected changes in planted pine area in the South have

important implications for future timber supplies, as a

significant share of southern timber supplies are projected to

come from planted stands (Haynes 2003). The area of planted

pine in the South has increased more than tenfold since 1950,

Figure 25.—Timberland area by stand-age class in the East.

mostly on private lands (Haynes et al. 2006). Planted pine

area on private lands increased by more than 25 million acres

between 1952 and 1997. Management intensification on

these industrial lands is one of the reasons some harvested

natural pine, mixed oak-pine, and hardwood stands are being

regenerated as pine plantations. Private landowners have

responded to market incentives and government programs,

including subsidized afforestation on marginal agricultural

land. Timber harvest is a crucial disturbance affecting

planted pine area, as other forest types may be converted to

planted pine. The privately owned area in pine plantations

is projected to increase by about 17 million acres by 2050,

approximately a 53-percent increase largely owing to the

addition of pine plantations on forest industry lands or lands

owned by timberland investors (Alig and Butler 2004a).

Conversely, many harvested pine plantations revert to other

forest types, mainly because of passive regeneration behavior

on nonindustrial private timber lands.

Extent of Area by Forest Type and Age Class 

or Successional Stage

Ecological processes and the species associated with those

processes within any forest ecosystem are associated with

vegetative structures (age of the vegetation, its diameter, and

height) and successional stages (variable species of vegetation).

In the East, about 58 percent of all timber land is classed as

having an average stand age of more than 40 years, 19 percent

is between 20 and 40 years in average stand age, and 23 percent

has an average stand age of less than 20 years (fig. 25). In the
Interim Update of the 2000 RPA Assessment 45

West, the average stand age is older (80 percent of the area has

timber aged 40 years or more) than for the East, reflecting the

fact that more areas in the West have never been harvested.

About 6 percent of the timberland area in the East is classed as

uneven aged compared with less than 1 percent in the West.

In 2002, about 65 percent of all timber lands were classified

as sawtimber-sized in the Western United States.4 Most of the

remaining area was split between seedling-sapling (15 percent)

and poletimber (17 percent). The area of nonstocked timber

land amounted to 4 percent of total timberland area. In the

East, 46 percent of timberland area was classed as sawtimber

in 2002, 28 percent was poletimber, and 26 percent seedling/

sapling. By comparison, in 1953, 29 percent of the timber land

in the East was classed as sawtimber.

The Nation’s forests are getting older in many areas of the

country, but age is a relative term. Compared to the early 20th

century, eastern forests are older, but they are only a fraction

of the average age of forests at the time of pre-European

settlement. From an ecosystem diversity perspective, this

maturation will lead to increased diversity of forest structure

but a decreased diversity of forest types because later

successional stages will continue to increase at the expense of

earlier successional stages.

Extent of Areas by Forest Type in Protected 

Area Categories as Defined by IUCN

There is worldwide interest in the extent of protection

of representative ecosystems so as to maintain a pool of

biodiversity for future generations, and various ways of

classifying the degree of protection are given to an area. The

classification scheme used by the International Union for

the Conservation of Nature (IUCN) includes the following

categories:

I. Strict nature reserve/wilderness area.

II. National park.

III. National monument.

IV. Habitat/species management area.

V. Protected landscape/seascape.

VI. Managed resource protection area.5

The IUCN classification scheme is based on the concept of

protection by legal statute and thus does not apply well to

private lands and some public lands in the United States.

Individual landowners may have no intention to harvest

timber, but subsequent owners may chose to harvest timber

or otherwise develop the land. Some organizations such

as the Nature Conservancy own land with the intention

of preservation, but this protected status may change as

organizational objectives change over time.

In 2002, about 77 million acres of forest land were classed as

reserved and include wilderness areas on Federal and State

lands and national parks. This estimate includes small areas of

4 To be classed as sawtimber, softwood trees must be at least 9.0 inches in diameter 4.5 feet above the ground and hardwood trees must be at least 11.0

inches. Seedlings are live trees less than 1.0 inch in diameter 4.5 feet above the ground and at least 1 foot in height, saplings are live trees 1.0 inch through

4.9 inches in diameter 4.5 feet above the ground, and poletimber trees are live trees at least 5.0 inches in diameter but smaller than sawtimber trees.

5 Category I is defined as an area of land and/or sea possessing some outstanding or representative ecosystems, geological or physiological features and/or

species, available primarily for scientific research and or environmental monitoring or a large area of unmodified or slightly modified land, and/or sea,

retaining its natural character and influence, without permanent or significant habitation, which is protected and managed so as to preserve its natural

condition. Category II land is a natural area of land and/or sea, designated to (a) protect the ecological integrity of one or more ecosystems for present and

future generations; (b) exclude exploitation or occupation inimical to the purposes of designation of the area; and (c) provide a foundation for spiritual,

educational, and recreational and visitor opportunities, all of which must be environmentally and culturally comparable. Category III land is an area

containing one, or more, specific natural or natural/cultural feature that is of outstanding or unique value because of its inherent rarity, representative or

aesthetic qualities, or cultural significance. Category IV is an area of land and/or sea subject to active intervention for management purposes so as to ensure

the maintenance of habitats and/or to meet the requirements of specific species. Category V is area of land with coast and sea as appropriate, where the

interaction of people and nature over time has produced an area of distinct character with significant aesthetic, ecological, and/or cultural value, and often

with high biological diversity. Safeguarding the integrity of this traditional interaction is vital to the protection, maintenance and evolution of such an

area. Category VI is an area containing predominantly unmodified natural systems, managed to ensure long-term protection and maintenance of biological

diversity, while providing at the same time a sustainable flow of natural products and services to meet community needs.
46 Interim Update of the 2000 RPA Assessment

private lands. The reserved forest land area in 2002 amounted

to 3 percent of the total forest land area in the East and 18

percent in the West (figs. 26 and 27). The area classed as

reserved in 2002 was about triple the area classed as reserved

in 1953. The remaining public forest land (242 million acres)

is classed in categories III–VI. It is in national monuments or

other custodial-managed areas, or it is in areas managed for

the sustainable use of natural ecosystems. Currently, tens of

millions of acres on Federal lands are classed in Category VI,

even though they may never be available for harvest. They are

protected by administrative action rather than legal statute.

A complete data set for the area of forest type in protected

areas is not yet available by age class or successional stage. We

expect that the area of reserved mid- to late-successional forest

types, such as maple-beech-birch, will continue to increase.

In the absence of disturbance, earlier successional forest

type groups, such as aspen-birch, will convert to these later

successional forest types. In the West, the area of larch and

redwood, both on reserved forest land and in total, is limited.

The Fragmentation of Forests

The fragmentation of forest area into small pieces affects

habitat quality and thus biological diversity. A nationally

consistent assessment of fragmentation was conducted by

using maps of forest land derived from satellite imagery at

0.09 hectare (ha) resolution (Riitters et al. 2002). The results

show that about three-fourths of all forest land is found

in close proximity to large (greater than 5,000 hectares or

12,000 acres), yet heavily fragmented forest land patches,

and the rest exists as smaller patches in mostly nonforested

regions. The assessment protocols took into account the fact

that fragmentation is a scale-dependent concept. Although

57 percent of all forest land is “core” in 2-ha neighborhoods,

the proportion decreases rapidly with landscape size, and

less than 1 percent of forest land is “core” in 590-ha or larger

neighborhoods (fig. 28). Similarly, although 69 percent of

all forest land is “interior” in 2-ha neighborhoods, less than

Figure 26.—Percent of forest land in reserved status by forest 

type in the East: 2002. 

Figure 27.—Percent of forest land in reserved status by forest 

type in the West: 2002. 

Figure 28.—Forest land fragmentation from national landcover maps. The chart shows percentage of forest land in the 

conterminous United States that is in landscapes of different 

sizes meeting the criteria for “core” ( , completely forested 

landscape), “interior” (r, more than 90 percent forested), 

and “dominant” ( , more than 60 percent forested). Open 

and closed symbols represent western and eastern RPA 

regions, respectively. Adapted from Riitters et al. (2002).
Interim Update of the 2000 RPA Assessment 47

Number of Forest-Dependent Species

Flather et al. (2004a) analyzed data on the distribution of 689

tree and 1,486 terrestrial animal species associated with forest

habitats (including 227 mammals, 417 birds, 176 amphibians, 191 reptiles, and 475 butterflies). For all taxa, the highest

richness classes are concentrated in the Southeast and in the

arid regions of the Southwest (fig. 30). Data on trends in the

number of forest species was available only for birds (fig. 31).

Areas with evidence of declining forest bird richness generally

occur in the East, with notable areas of decline in the Mississippi lowland forests, southeastern coastal plain, northern New

England, southern and eastern Great Lakes forests, and central

Tallgrass prairie. Areas with evidence of increasing forest bird

richness tend to occur in the West and include the great basin,

northern Rocky Mountains, northern mixed grasslands, and

southwestern deserts.

For the time period 1966 to 2000, 26 percent of native forestdependent bird species increased in abundance, 27 percent

decreased, and 47 percent showed no change (Sieg et al.

2004) (fig. 32). Even when the percentage of species with

increasing and decreasing trends is compared early (1966–79)

and late (1980–2000) in this period, we tend to see evidence

for a balance in the number of species with increasing and

decreasing populations (fig. 32).

Figure 29.—Geographic distribution of relatively intact 

forests. The map shows the relative amount of “interior” 

forest at 7 ha scale shaded from low (red) to high (green) 

for areas containing more than 60 percent forest overall. 

The large green areas contain the major reserves of less 

fragmented forest land. Adapted from Riitters et al. (2002).

half is “interior” in neighborhoods larger than 66 hectares. A

direct relationship exists between “core” status and distance to

nearest forest edge (Riitters et al. 2002). Overall, 44 percent

of forest land is within 90 meters of forest land edge, 62

percent is within 150 meters of forest land edge, and less than

1 percent is more than 1,230 meters from forest land edge.

Although fragmentation is pervasive, forest land usually is

“dominant” where it occurs; at least 72 percent of all forest

land is in neighborhoods that are at least 60 percent forested for

neighborhoods up to about 5,000 hectares in size (fig. 29).

Box 10

Impact of roads on fragmentation—The effects of

roads on forest fragmentation were not specifically

incorporated in earlier national assessments (Riitters et

al. 2002, USDA Forest Service 2004) that were based on

land-cover maps alone. Some roads are not large enough

to be seen on satellite imagery, and as a result were not

shown on the land-cover map. In a comparative analysis,

Riitters et al. (2004) evaluated the degree and location

of incremental changes in forest fragmentation resulting

from superimposing detailed road maps upon the landcover maps. There was more overall fragmentation when

roads were included, but the land-cover maps alone

detected greater than 80 percent of the forest edge and

greater than 88 percent of the fragmentation of intact

core forest that was detected by road and land-cover

maps together. Important exceptions include many

large regions of publicly owned forest land where small

roads traverse relatively undeveloped forest landscapes.

Nevertheless, the overall geographic patterns of core

forest are very similar with and without roads. In both

cases, the largest reserves of core forest are along the

Oregon-Washington coast, northern Minnesota, New

York, Maine, and in the northern Rocky, Ouachita, Ozark,

and Appalachian Mountain ranges. Road maps should

be used in future assessments if interest centers on roadcaused fragmentation. Otherwise, land-cover maps alone

may provide an adequate representation of the national

geography of forest fragmentation.
48 Interim Update of the 2000 RPA Assessment

Figure 30.—Geographic variation in the number of forest-associated species occurring within ecoregions for all taxa (a), 

trees (b), mammals (c), birds (d), amphibians (e), reptiles (f), and butterflies (g). 

The interpretation of these forest bird population trends is

complicated by the fact that not all native birds that breed

in the forested habitats of the United States winter here (see

Sieg et al. 2004). In fact, more than half of the landbirds that

breed in temperate North America spend the winter months

at the lower subtropical and tropical latitudes (Askins et al.

(a) (b)

Richness classes were based on percentiles defined to approximately reflect the upper 90th percentile (dark red), the 80th to 89th percentile, the 60th to 79th

percentile, the 20th to 59th percentile, and the lower than 20th percentile (lightest red). The highest richness class represents the 10 percent of ecoregions with

the greatest count of species. For details, see Flather et al. (2004b).

1990). Consequently, the factors causing increases or decreases

in forest-breeding bird populations could be attributable to

conditions either on the breeding grounds, along migration

corridors, or in the wintering areas. Evidence suggests that

human activities altering habitat in both the temperate and

tropical regions affect migratory bird population trends

(c) (d)
Interim Update of the 2000 RPA Assessment 49

(f) (e)

(g)

The Status of Threatened and Endangered 

Species

As of November 1, 2004, 1,264 species were formally listed as

threatened or endangered within the United States. Of that, 746

were plants (59 percent) and 518 were animals (41 percent).

Since the 2000 Renewable Resources Planning Act (RPA)

Figure 30.—Geographic variation in the number of forest-associated species occurring within ecoregions for all taxa (a), 

trees (b), mammals (c), birds (d), amphibians (e), reptiles (f), and butterflies (g) (continued).

(Robbins et al. 1989). A comparison of recent abundance trends

(1980–2004) between permanent resident and neotropical

migrant birds (Sauer et al. 2005) indicates that permanent

residents have fared better (51 percent with positive trends)

than long-distant migrants (40 percent with positive trends)—

an indication that environmental factors off the breeding areas

are playing a role in observed population dynamics.

Richness classes were based on percentiles defined to approximately reflect the upper 90th percentile (dark red), the 80th to 89th percentile, the 60th to 79th

percentile, the 20th to 59th percentile, and the lower than 20th percentile (lightest red). The highest richness class represents the 10 percent of ecoregions with

the greatest count of species. For details, see Flather et al. (2004b).
50 Interim Update of the 2000 RPA Assessment

Figure 31.—Trends in forest bird richness by ecoregion from 

1975 to 1999. 

Change in richness is estimated by lambda, which is the ratio of estimated

richness in 1999 to the estimated richness in 1975. Values of lambda

greater than 1.0 indicate increasing richness (green shades); values of

lambda less than 1.0 indicate declining richness (red shades). For details,

see Flather et al. (2004b).

Figure 32.—Percentage of breeding birds whose population 

trends have increased or decreased significantly (P<0.10) 

over three time periods: (1) 1966–2000, (2) 1966–1979, and 

(3) 1980–2000 (Sieg et al. 2004).

(1) (2)

(3)

Box 11

Housing change and relative species richness of forest birds—The amount of housing in the rural United States has

been growing. This growth removes and alters wildlife habitat, potentially introduces exotic species, and increases human

disturbance with potentially severe long-term effects on biodiversity. Two studies, one regional and one national, sought to

better understand the influence of housing growth and land use intensification on breeding birds in the United States.

The regional study (Lepczyk et al. In review), conducted across the Midwestern United States, found that both total and

native breeding bird richness were highest where human influence was lowest. Conversely, exotic bird species tended to increase with higher housing density and higher proportions of intensive human land uses. The fact that total richness declined

with increasing human influences indicates that the observed gain in exotic richness was not sufficient to offset the loss of

native species.

A study that focused on forest breeding birds across the conterminous United States found the observed relationship between

housing density and land use intensification was more varied than the regional study indicated. Consequently, the relationship

between bird diversity and the human footprint is more complex than originally thought and may depend on where a particular

place falls along a gradient of pristine to highly altered landscapes. This variable response suggests that efforts to counteract

the potentially negative influence of housing growth and human land use intensification through land management activities

will be conditional on the peculiarities of the region under consideration.
Interim Update of the 2000 RPA Assessment 51

(a)

Wildlife Assessment (Flather et al. 1999), 182 species have been

added to the list. Since the mid-1970s, the number of species

that has been added to the list has varied over time (fig. 33)

(Flather et al. 2004b). As described in Flather et al. (1999),

the Endangered Species Act listing history is characterized by

three phases defined primarily by the rate at which species were

listed. Early in the listing history, species were added at a relatively moderate rate and culminated in the mass listing of cactus species that were threatened by the plant trade. Phase 1 was

followed by a period of relative inactivity. Phase 3 of species

listing was characterized by a high rate of new species being

classified as threatened and endangered.

Although phase 3 is bounded by the listing moratorium that

occurred in April 1995, once the moratorium was lifted, the

rate of listings appears to have resumed to premoratorium

levels. The listing rate in phase 3 was caused primarily by new

plant listings as animal listings have increased more slowly

than plants. Since the 2000 RPA Assessment, however, the rate

of species listed as threatened or endangered has declined five

fold. This decline cannot be attributed to a reduced number of

species that deserve protection for there are enough candidate

(c) (b)

Figure 33.—Cumulative number of species listed as 

threatened or endangered under the Endangered Species Act 

of 1973 from July 1, 1976, through November 1, 2004, for 

(a) plants and animals, (b) vertebrates, and (c) invertebrates 

(Flather et al. n.d. [b]) (continued).
52 Interim Update of the 2000 RPA Assessment

species to support a much higher listing rate for years to come.

Rather, in 2003, the U.S. Fish and Wildlife Service estimated

that processing the nearly 300 candidate species would require

$153 million, an amount nearly 10 times its budget for all

listing activities in fiscal year 2005 (Stokstad 2005).

Animal taxa that have contributed the greatest number of

new species to the list include fish, mollusks, and insects.

The number of counties having seven or more threatened

and endangered species is concentrated in the southern

Appalachians, Atlantic and Gulf coastal areas, and the arid

Southwest (fig. 34).

Data from NatureServe shows a somewhat similar pattern for

at-risk species based on biological criteria (Flather et al., n.d.

[a], n.d. [b]) (fig. 35). Ten percent of the counties having the

highest count of at-risk species are again found in the southern

Appalachians, peninsular Florida, Atlantic and Gulf coasts,

and the arid Southwest. The count of at-risk species, however,

indicates a potentially new area of conservation concern in

the driftless area of southwestern Wisconsin and the northern

mixed forests around Lake Superior.

Recent extirpation of species is most prominent in the

southern third of the conterminous United States (fig. 36).

More than 30 species of plants and animals have been lost

in California, Texas, Tennessee, Alabama, and Florida.

Invertebrates represent the majority of species lost in Alabama

and Tennessee, whereas plants are a notable component of the

extirpated biota in Florida and California.

The places that have gained threatened or endangered species

have generally been in areas where other threatened or endangered species are already concentrated. States where species

extirpations are most prominent coincide roughly with those

areas supporting high concentrations of at-risk species. One of

the arguments for focusing conservation efforts in those areas

supporting high numbers of species thought to be at risk of

extinction is that these areas represent places where species are

likely to be lost from the species pool in the future. The results

reported here support this argument. Land and resource management policies targeting those factors causing increased rarity in hotspots have the potential to avert future species losses.

Figure 35.—The geographic distribution of county-level 

counts of species considered to be at risk of extirpation 

(conservation rank N1, N2, and N3) from the conterminous 

United States. 

The highest count class (28–111 species) represents 10 percent of counties

with the highest occurrence of at-risk species. County-level occurrence data

were not available for New Hampshire and Massachusetts. For details, see

Flather et al. (n.d. [a]).

Figure 34.—The geographic distribution of county-level 

counts of species formally listed as threatened and endangered by the Endangered Species Act in the conterminous 

United States. 

The highest count class (7–35 species) represents 10 percent of counties

with the highest occurrence of threatened or endangered species.

County-level occurrence data were not available for New Hampshire and

Massachusetts. For details, see Flather et al. (n.d. [b]).
Interim Update of the 2000 RPA Assessment 53

Figure 37.—The number of terrestrial animal species 

(mammals, birds, amphibians, reptiles, and some insects 

[grasshopper and butterfly species only]) associated with 

(a) forest habitats and (b) the number of aquatic species 

(fish and mollusks) that have been extirpated within each 

State.

(a)

Aquatic species were not assigned to broad habitat infinity classes and so 

the counts within each State reflect species associated with all habitats. 

Because range occupancy was estimated for only extant species, and 

because historical and current range size was measured at the State level, 

Hawaiian species are not reflected in these data. For details, see Flather et 

al. (2004c).

(b)

Figure 36.—The geographic distribution of State-level 

counts of species considered to be extirpated from a State 

(conservation rank SX and SH) for the conterminous United 

States. 

The highest count class (29–96 species) represents 10 percent of States

with the highest count of extirpated species. Pie charts represent the

proportional composition of extirpated species from each State that is

vertebrate, invertebrate, and plant species. For details, see Flather et al. 

(n.d. [a]).

Number of Forest-Dependent Species That 

Occupy a Small Portion of Their Former 

Range

Geographic range data for 1,642 terrestrial animals associated

with forests shows that 88 percent of species fully occupy their

former range as estimated by State-level occurrence (Flather et

al. 2004c). Of the 193 species that have been extirpated from

at least one State, 72 percent still occupy at least 90 percent of

their former range. The number of species that now occupy 80

percent or less of their range varies by taxonomic group (fig. 37).

Range contraction of this magnitude is most commonly observed

among mammals (5.7 percent), followed by amphibians (2.3

percent), and birds (1.4 percent). States that have lost the greatest

number of terrestrial animal species associated with forest

habitats are concentrated in the Northeast (fig. 38).
54 Interim Update of the 2000 RPA Assessment

Population Trends in Recreationally 

Harvested Wildlife Species

Available data suggests that big game and small game populations and harvests differ in a very fundamental way. Big game

populations and harvests have, with a few regional exceptions,

increased consistently from 1975 to 2000 (fig. 39). For several

species, such as for wild turkey and deer, the increases have

been substantial. By contrast, available data suggests that small

game populations and harvests have declined (Flather et al.,

n.d. [a]).

Because few States provided population data for small game

species, the declines in population are suggested by the

reported declines in small game harvests. On average, between

1975 and 2000, small game harvests declined by 49 percent. It

is not possible to argue definitively that this decline is caused

by population reductions because harvests can change for

reasons other than population status. For example, declines

in the accessibility of land for hunting, changes in species

preferences that hunters pursue, and declines in the number

of days devoted to hunting small game could all explain the

observed reduction in small game harvest. Population trends

derived from the North American Breeding Bird Survey 

(Sauer et al. 2005), however, suggest that small game harvest

declines may be caused in part by population declines. Of the

13 small game bird species monitored by the Breeding Bird

Survey, 10 showed evidence of declining trends (four of which

were statistically significant declines).

Within species classified as small game, available data suggests

that declines are prominent among those species associated

with grassland, early successional, and farmland habitats.

For example, three of the five small game species (northern

bobwhite, cottontail, and prairie grouse) with the greatest

percent decline in harvests are clearly associated with grassland

and agricultural habitats. This pattern was reinforced by trends

derived from the Breeding Bird Survey which show that

populations of gray partridge, ring-necked pheasant, greater

prairie chicken, and northern bobwhite have declined. These

species are all associated with grassland/agricultural systems.

There are regional exceptions to the national relationship

between population and harvest. For examples, deer and elk

harvests increased in all regions except the Pacific Coast and

harvests of pronghorn and black bear in the Rocky Mountains

region have declined despite population increases.

Figure 38.—The percent of listed (a) plant and (b) animal species that now occupy varying amounts of their former geographic range.

Percentage is based on only those species for which range reduction data were available. Values reported on the x-axis represent the mid-points of a 5-percent

interval. For details, see Flather et al. (2004a).

(a) (b) Percent of species

Percent of range occupied

Percent of species

Percent of range occupied

Plants Animals
Interim Update of the 2000 RPA Assessment 55

Figure 39.—Harvest trends in selected species and species groups of big game for the Nation and RPA regions for 1975 

through 2000 in 5-year increments.

The number of States providing data is given by “n=”. For details, see Flather et al. (n.d. [a]).

Box 12

Conservation easements on private lands—Land conservation in the United States has evolved since earlier eras which

emphasized Federal Government acquisition and reservation such as establishment of the Forest Reserves in 1891 and the

National Park Service in 1916. As the Federal estate moved toward maturation in the mid- to late 20th century, new methods of

conserving natural lands for the public good have been emerging. Chief among these is the conservation easement.

Conservation easements became much more common after passage of the Uniform Conservation Easement Act in 1981. A

conservation easement is a legal document that transfers some development and management options from the property owner

to a nonprofit or government agency that holds those rights. Under a conservation easement, the property owner is selling or

donating some of the property rights to the easement holder. In return, the owner continues to own the property and use the

land subject to the restrictions imposed by the easement.
56 Interim Update of the 2000 RPA Assessment

Rangeland Area

The rangeland and grazed forest land base occupies about onethird of the Nation’s land area (Vesterby and Krupa 2001).

The national trend in the area of rangeland, however, has been

slowly downward over the past century (Conner et al. 2001).

Van Tassell et al. (2001) projected continued slow declines in

the U.S. rangeland base, especially in the West and Northeast.

In the South, the area of rangeland was expected to remain

fairly constant. A recent, still unpublished analysis of Census

Bureau data corroborates the above work (table 5). The three

States losing the most privately owned rangeland and pasture

between 1987 and 1997 were Arizona (6.2 million acres),

Nevada (3.5 million acres), and Colorado (1.2 million acres).

Changes in the extent and distribution of rangeland vary widely

by community type. An analysis of the National Resources

Inventory land cover data in relation to Küchler potential

natural vegetation classification data has shown that the largest

rangeland losses have occurred in the northern Great Plains,

the southern Rocky Mountains, and the semidesert and desert

Southwest (fig. 40).

Box 12 (continued)

There are many types of conservation easements. Federal funding for conservation easements through the Land and Water

Conservation Fund Act of 1965 has been declining, especially since the 1980s. In part, this decline, along with economic

prosperity, increasing demand for open space, and other factors, enhanced the rise of non-Federal conservation easements. The

widespread variability in the institutions, organizations, and properties involved make a national assessment of the role and

extent of conservation easements in land conservation a very difficult task.

Federal agencies, including the Forest Service, and various State and local governments are active in conservation easement

acquisition. Most Federal programs for conservation easements are agency sponsored grant-in aid or other incentive programs.

The Conservation Reserve Program in the 1985 Farm Bill is an example of this type of conservation easement. Other examples

include the Forest Service’s Forest Legacy program and the National Fish and Wildlife Foundation.

State government involvement in conservation easements varies. For example, California has a wide array of State

conservation programs under administration of the California Resources Agency. Florida’s “Florida Forever” program

receives $300 million in annual funding from the State to support a variety of environmental services and values.

Local government involvement in conservation easements varies around the country. No centralized database tracks these

activities. An example is New York City’s efforts to protect the watersheds that provide the city’s drinking water through

conservation easements and fee simple property. Also, Lancaster County, Pennsylvania, has an Agriculture Reserve Board to

which landowners apply to sell development rights and agree to maintain the land in farming.

Nongovernmental organizations such as the Nature Conservancy and land trusts are placing additional areas under various

types of protection. The area of water and land protected by the Nature Conservancy amounted to 7.6 million acres in 2004.

The area of land trusts increased from 1.9 million acres in 1990 to 6.2 million in 2000.
Interim Update of the 2000 RPA Assessment 57

Table 5.—Area and percentage of privately owned rangeland and pastureland lost between 1987 and 1997 by State (for those 

States having more than 1 million acres of rangeland and pastureland in 1997) and assessment region.

1

 State land area is from 1998 USA counties, based on 1990 Census (http://censtats.census.gov/usa/usa.shtml).

2

 Rangeland/pasture area data from U.S. Census of Agriculture (http://www.nass.usda.gov/census).

3

 Rangeland/pasture area data include only private holdings.

Assessment 

region or State

Land area

(million ac.)1

Area of rangeland and pasture 

(ac.)2, 3 Loss or (gain) Loss (gain) in relation to 

entire State (percent) 1987 1997 Acres Percent

Iowa 35.76 1,452,248 1,440,627 11,621 0.8 < 0.1

Missouri 44.09 3,736,320 3,715,717 20,603 0.6 < 0.1

North 413.45 11,258,408 10,295,362 963,046 8.6 0.2

Alabama 32.48 1,234,245 1,062,424 171,821 13.9 0.5

Arkansas 33.33 1,483,476 1,466,303 17,173 1.2 < 0.1

Florida 34.52 4,495,653 4,069,927 425,726 9.5 1.2

Kentucky 25.43 1,232,448 1,127,746 104,702 8.5 0.4

Louisiana 27.88 1,011,276 1,006,084 5,192 0.5 < 0.1

Oklahoma 43.95 14,261,454 15,431,722 (1,170,268) (8.2) (2.7)

Texas 167.63 86,802,117 86,073,441 728,676 0.8 0.4

Virginia 25.34 1,180,356 1,074,183 106,173 9.0 0.4

South 534.48 115,535,470 114,679,943 855,527 0.7 0.2

Arizona 72.73 29,840,297 23,681,829 6,158,468 20.6 8.5

Colorado 66.39 21,173,673 19,943,701 1,229,972 5.8 1.9

Idaho 52.96 5,528,460 4,589,326 939,134 17.0 1.8

Kansas 52.37 13,254,094 14,062,576 (808,482) (6.1) (1.5)

Montana 93.16 39,459,291 37,974,463 1,484,828 3.8 1.6

Nebraska 49.20 20,443,481 21,876,974 (1,433,493) (7.0) (2.9)

Nevada 70.28 8,684,697 5,232,909 3,451,788 39.7 4.9

New Mexico 77.67 40,964,044 40,737,445 226,559 0.6 0.3

North Dakota 44.16 10,206,220 10,375,089 (168,869) (1.7) (0.4)

South Dakota 48.57 23,069,181 23,588,662 (519,481) (2.3) (1.1)

Utah 52.59 7,010,858 9,247,212 (2,236,354) (31.9) (4.3)

Wyoming 62.15 29,624,287 30,051,421 (427,134) (1.4) 0.7

Rocky Mountain 742.22 249,258,583 241,361,607 7,896,976 3.2 1.1

California 99.82 17,111,110 14,384,908 2,726,202 15.9 2.7

Oregon 61.44 10,409,418 9,663,817 745,601 7.2 1.2

Washington 42.61 4,875,988 4,944,327 (68,339) (1.4) (0.2)

Pacific Coast 573.03 34,276,665 30,547,641 3,729,024 10.9 0.7

United States 2,263.18 410,329,126 396,884,553 13,444,573 3.3 0.6
58 Interim Update of the 2000 RPA Assessment

Box 13

Decline in aspen and other early successional species in 

the West, Lake States, and Northeast—Even without human-caused disturbance, forests will change as a result of

natural disturbances or natural succession. Since the 1980s,

ecologists have concluded that aspen is in steady decline in

many parts of the Intermountain West, particularly in Utah

(Bartos 2001). The combination of modern fire suppression

and a steady increase in elk herbivory has prevented aspen

regeneration in some forests, with conifer understories now

widely overtopping aspen stands in a slow successional process that takes more than a century to play out (Bartos et al.

1983). Aspen clones are able to persist in a suppressed state

in the understories of conifers for many years, but without

major fires, aspen stands may continue to decline. Evidence

indicates, however, that aspen has not started to decline in

abundance in all locations in the West (Manier and Laven

2002). For the Lake States of Minnesota, Wisconsin, and

Michigan, the total area of the aspen-birch forest type group

decreased by 7.8 million acres between 1953 and 1997.

Figure 40.—National net change in Küchler types from 

1987 to 1997.

Net changes in non-Federal rangeland area by Küchler vegetation type

between 1987 and 1997. The largest losses are ecosystems dominated by

wheatgrasses and needlegrasses (red, yellow, and brown) in the northern

Great Plains and Colorado, grama and galleta grasses (yellow) in Arizona

and New Mexico, and pinyon-juniper (brown) in the Southwestern United

States. To a lesser extent, creosote bush (tan) has also declined in the desert

Southwest. The greatest increases are found in the sagebrush steppe (dark

green) in the Great Basin and the California oak woodland (dark green).

Data from National Resources Inventory.

Summary

The largest reserves of intact forest are concentrated on public

lands and the largest share of intact forest is contained in the

NFS. Indeed, for some types of ecosystems, only NFS lands

contain significant amounts of intact forest. The status of

adjacent private lands can determine the degree of intactness

that can be achieved on public lands. For example, urbanization

of private land next to public land increases the likelihood of

invasive species on the public land. Even if public lands can be

kept intact, changes in biological diversity will occur as forests

and habitats evolve and as natural disturbances/succession lead

to change such as the decline in aspen in parts of the West and

North.

Those species that have been able to adapt to human activities

did well in the 20th century, as have species such as elk that are

highly valued and managed by humans. Species that need large

undeveloped landscapes or specialized habitats vulnerable to

development pressures did not do as well. Many species that

are formally listed as threatened or endangered share some of

these characteristics.

The rate of species listed as threatened or endangered has

declined five fold since the 2000 RPA Assessment (USDA

Forest Service 2001). This decline may not reflect so much

on the condition of threatened and endangered species as on

funding and other factors. Conservation efforts should continue

to focus on those areas supporting higher numbers of species

thought to be at risk of extinction. Most future forest loss

will be to development/urbanization. We can expect more

widespread occurrences of invasive species as this development

progresses.

The area of private lands protected by conservation easements

is growing. These easements offer various levels of protection,

but most minimize the possibility for urbanization.

A development of the past 15 years has been forest industry’s

sale of large parcels of timber land, primarily to timber investment management organizations and real estate investment

trusts. The objective of industry ownership was generally to

protect a source of timber supply and reduce the risks of timber
Interim Update of the 2000 RPA Assessment 59

Box 14

Exotic plant richness as an indicator of ecosystem 

health—The colonization of native plant communities by

exotic species poses one of the greatest threats to natural

ecosystems in the United States (Sieg et al. 2005). Invasions

of plant species not native to the United States can alter

the capacity of lands to support biodiversity and to provide

services to humans. By displacing native species, invasive

plants reduce biodiversity, threaten at-risk species, and can

alter important ecological processes such as hydrologic and

fire regimes in ways that reduce the capacity of ecosystems

to provide services like water, forage, and recreation.

The understanding of patterns of exotic species hotspots

and environmental attributes that are related to these

concentrations is a fundamental step in developing a national

strategy for managing invasions.

Sieg et al. (2005) did a study that related county-level data

on exotic plant species richness for the conterminous States

to six variables: Population density; herbarium presence;

average distance to the five closest counties with at least

one herbarium; mean elevation; county area; and mean

annual temperature. The positive relationship between

human population density and exotic plant species richness

is due in part to direct or indirect introductions by humans.

There is the expectation that there would be increasing

numbers of exotic plant species in counties with herbaria

and decreasing numbers with increasing distances from

counties with herbaria, suggesting that the better studied

counties tend to be characterized by higher exotic plant

species richness. Results indicate that hot spots of exotic

species richness are associated with low mean elevation and

low mean annual temperature. These results are consistent

with the pattern of exotic species hot spots in low elevation

coastal settings in the Southeastern United States as well

as in the Northeastern United States that are characterized

by generally lower mean annual temperatures. The positive

relationship between area sampled and species richness

is well accepted. The model used in the study correctly

classified more than 93 percent of the county-level hot and

cold spots of exotic species richness (fig. 41).

Figure 41.—(a) Exotic plant species hotspots and coldspots. (b) Counties misclassified. False hotspots are those 

counties that were predicted to be hotspots but were actually coldspots, and false coldspots were counties predicted to be 

coldspots but were actually hotspots.

(a) (b)
60 Interim Update of the 2000 RPA Assessment

price volatility. Because the industry managed its lands for timber production, this ownership generally assured maintenance

of large landscapes. The sale of forest industry lands creates

uncertainty about the long-term nature of these lands and the

implications for associated biodiversity. Clutter et al. (2005)

suggest that turnover in timberland ownership will continue

to accelerate fragmentation issues on the urban-rural fringe.

Hagan et al. (2005) found that in the northern forest, many of

the new landowners do not have biodiversity practices and policies as strong as industry land owners.

Stability in the area of forest land does not mean no changes

have occurred in forest area. Between 1982 and 1997, 23

million acres went out of forest land and 26.6 million acres

went into forest land. Areas converted from forests went mainly

to developed uses. Areas going into forest came primarily from

pasture land. Acres that enter and exit the forest land base can

be quite different; entering acres may be bare ground or have

young trees, while exiting acres often contain older trees before

conversion to developed uses. Forest land lost to development

seldom changes back to a more natural land cover.

Forests in the United States are getting older. This aging will

lead to increased diversity of forest structure, but to a decreased

diversity of forest types because later successional stages will

continue to increase at the expense of earlier successional

stages. Although forests are getting older, duplication of preEuropean conditions is not possible.

Expected increases in plantation areas in the South will be

the source of much of the United States’ increase in softwood

timber supply. This increase will tend to decrease prices and

reduce pressure for harvest on some private timber lands.

Reduced harvest will change the dynamics of temporal changes

in habitat and biodiversity.
Interim Update of the 2000 RPA Assessment 61

If renewable resource inventories are stable or increasing on the

land or if outputs are stable or increasing without diminishing

the inventories, we can infer that productive capacity is being

maintained. Inventories and outputs reflect the influences of

harvesting, land use changes, natural disturbances, natural

processes, management activities, and trade in renewable

resources.

Forest Products

Area of forest land and net area of forest land available for 

timber production—About 504 million acres, or 67 percent of

the total forest land area, is classed as timber land. These forest

land areas are capable of producing more than 20 cubic feet

per acre per year of industrial wood that is not withdrawn from

timber utilization by statute or administrative regulation (Smith

et al. 2004). Timber land is used here as a proxy for the net area

of forest land available for timber production. Timberland area

includes currently inaccessible and inoperable areas and thus

overestimates the net area of forest land available for timber

production. Also, no consideration is given to owner objectives

regarding timber production when forest land is classed as

timber land. Most of the timber harvested for roundwood

products comes from this part of the forest resource base.

About 72 percent of the timber land is in the Eastern United

States; in the Western United States, timber land is found

primarily in Montana, Idaho, Colorado, and the Pacific Coast

States. Timberland area has consistently amounted to about

two-thirds of the forest land area since the 1950s.

Growing stock available for timber production—The volume

of hardwood growing stock on timber land generally increased

for the Nation as a whole and across ownerships during the

period 1953–2002 (fig. 42). An exception was a downturn in

hardwood inventories on forest industry lands, which may indicate conversion of hardwood stands to softwood.

The volume of softwood growing stock on timber land

increased from 1953 through 2002. (fig. 43). Between 1987 and

2002, the volume increased on national forest and nonindustrial

private timber land. Volume decreased on the forest industry

ownership, in part because of decreased area in this ownership.

Growing stock is defined as timber inventory that includes live

trees of commercial species meeting specified standards of

quality or vigor. Cull trees are excluded. Growing stock volume

includes trees 5.0 inches diameter breast height and larger. As

with the definition of “timber land,” no allowance is made for

economic accessibility or operability and thus growing stock

volume may overstate the volume actually available.

Figure 42.—Hardwood growing stock inventory by ownership. Figure 43.—Softwood growing stock inventory by ownership.

Maintenance of Productive Capacity of Forest Ecosystems
62 Interim Update of the 2000 RPA Assessment

Area and growing stock of plantations—The area of

plantations—mostly softwoods in the East—amounted to

41.9 million acres in 2002. The planted area amounts to 10.9

percent of all U.S. forest land in the East. Total growing stock

volume in these planted areas amounts to about 7 percent of the

total growing stock volume in the East. Southern pines are the

dominant species on about three-fourths of the planted area in

the East.

An estimated 13.6 million acres of planted forest are in the

West; they primarily augment natural regeneration after harvest

and ensure adequate stocking of desired species. Planted trees

are often used to supplement natural regeneration and after

5 years or so, it can be difficult to differentiate planted and

natural areas in the West.

The Southern United States has witnessed a substantial

decrease in the area of natural pine and a rapid increase in

the area of planted pine over the past 50 years. The area of

planted pine is now about equal to the area of natural pine. The

loss of natural pine is largely due to land use conversions and

transitions to planted pine and to upland hardwood following

final harvest.

Annual removal of wood products compared to the volume 

determined to be sustainable—When Federal and some other

public agencies produce wood products, production is generally

planned within the frame of an overall plan that considers

the management of all resources. These plans generally

have in them some notion or intention to manage resources

in a sustainable fashion. For timber, these plans would at a

minimum include the objective that timber harvests should be

at a level that can be maintained in the foreseeable future.

According to Butler and Leatherberry (2004), 3 percent of

family forest land owners had prepared written management

plans that covered 20 percent of the total private forest land

area. Some plans on private lands may include consideration of

sustainable outputs and some may be based solely on financial

considerations. On private lands, the concept of sustainable

outputs can be dependent on price and other workings of

the market place. For example, higher prices may lead to

more intensive management that could increase the level of

sustainable output of wood products. In 2001, 8 percent of the

timber output was produced on public lands and 92 percent on

private lands.

From available data, the growth-removal ratio is a coarse-filter

measure that approximates the notion of sustainable production:

If the Nation is growing more wood than it is cutting, this ratio

implies that current levels of wood production are sustainable.

Growth is assumed to be a measure of sustainable output. The

indicator, however, conveys no information about quality,

forest types, size, and other attributes of growth and harvest.

The indicator is affected by imports of timber products, forest

management, and natural processes such as losses to mortality.

Trends for the Nation as a whole indicate that growth exceeds

removals for both softwoods and hardwoods (fig. 44). In total,

the ratio of growth to removals was 1.49 in 2001. The growthremoval ratio for all species declined from 1976 to 1986. The

increase from 1986 to 2001 reflects primarily the decrease

of harvest on national forests. The growth-removal ratio for

hardwoods was essentially unchanged from 1996 to 2001.

A striking trend is an increase in the ratio for softwoods in the

Pacific Coast region between 1991 and 1996. The rise reflects

decreased harvesting on public lands and increased growth on

timber stands that were regenerated after harvest during the 20th

Figure 44.—Growth-removal ratios by softwoods and 

hardwoods.
Interim Update of the 2000 RPA Assessment 63

century (fig. 45). The growth-removal ratios for both softwoods

and hardwoods in the South were relatively stable between

1996 and 2001after declining from 1976 to 1991. Current

growth measures in the South do not reflect anticipated growth

on millions of acres of plantations expected to reach maturity

over the coming decades. The trees are not yet large enough to

be classed as growing stock.

Removals continue to exceed growth on the forest industry

ownership (fig. 46). The ratios on this ownership were little

changed between 1996 and 2001. The growth-removal ratio on

the nonindustrial private ownership was little changed between

1996 and 2001. The decrease in harvest on national forests is

reflected in an increase in the growth-removal ratio between

1991 and 1996. The ratio for this ownership was more stable

between 1996 and 2001.

Annual removal of nontimber forest products compared to 

the level determined to be sustainable—Annual or periodic

harvest of nontimber forest products is largely undocumented

in a systematic way, especially on private lands (Alexander

2004). Many case studies and examples from anecdotal

information, however, document the widespread use and

importance of nontimber forest products (Jones et al. 2002).

Nontimber forest products include medicinal plants, food and

forage species, floral and horticultural species, resins and oils,

materials used for arts and crafts, and game animals and fur

bearers. Some management issues regarding nontimber forest

products are discussed by Kerns et al. (2002). For example, a

major gap in current knowledge is how harvesting practices

affect resource productivity, adversely or positively.

Certification of management of forest land adds a new

dimension to making judgments about sustainable production

of wood products (see box 15).

Figure 45.—Ratio of net annual growth to removals by region. Figure 46.—Ratio of net annual growth to removals by 

ownership.

North

South

Rocky Mountains

Pacific Coast

United States National forests

Other public

Forest industry

Nonindustrial 

private

All owners
64 Interim Update of the 2000 RPA Assessment

Box 15

Certification—Forest certification aims to identify forest

land that is managed to meet agreed-upon standards and

sometimes to label products originating from those forests

(Hansen et al. 2006). Forest certification involves an independent verification that forests are being managed and that

products are being produced that minimize or avoid harm to

the natural forests and the human systems they support.

The ideas of certifying and publicly advertising a wellmanaged forest in the United States goes back to 1941 when

the American Tree Farm System was created. This program

is now sponsored by the American Forest Foundation. Other

forest certification systems include: the Forest Stewardship

Council spearheaded by the Worldwide Fund for Nature;

the Sustainable Forestry Initiative initiated by the American

Forest and Paper Association, and Green Tag developed by

the National Forestry Association mainly for nonindustrial

forest owners.

The above certification programs are performance based.

The certifying organization sets most if not all performance

criteria and oversees the assessment process to ensure

conformance. Under systems-based certification such as

International ISO 14001, the organization or individual

seeking certification identifies its own environmental aspects

and impacts, sets its own goals and targets, and devises an

environmental management system to address them. The

system does not demand that any particular performance

level be attained.

Millions of acres of U.S. forest land have been certified by

one system or another. To date, most of the acreage has

been for private lands, but some State and county-owned

forest land is also certified. Very little federally owned forest

land has been certified. The Forest Service1 and the Pinchot

Institute have signed a joint venture agreement to evaluate

the potential consistency of forest certification with the

Forest Service’s mission to conserve and sustainably manage

Federal public land.

1 For details, log on to http://www.fs.fed.us?news/2005/releases108/factsheets.pdf.

Box 16

Expectations for future timberland area, forest management types, and private inventories—Between 1953 and

2002, U.S. timberland area declined by 5 million acres, or

about 1 percent, to 503.5 million acres. Haynes et al. (2006)

project a further decline of about 3 percent by 2050. The major cause of loss in timberland area will be conversion to developed uses (e.g., residential and commercial building sites)

rather than conversion to agriculture which was the dominant

competing use in earlier decades.

Several significant recent trends in private timberland

ownership are expected to continue. The result will be a

smaller private timberland base and a more numerous and

diverse set of owners with smaller parcels in closer proximity

to urban areas. Land held by the forest industry group (firms

integrated to processing) will continue to decline through

sales to institutional and other financial investors (Timber

Investment Management Organizations and Real Estate

Investment Trusts). These groups manage for production of

timber and for appreciation in the value of the forest land

asset but do not operate timber processing facilities. The

land base of nonindustrial ownerships is also projected to

decline, by more than 12 million acres or about 4 percent by

2050, continuing the trend of the past 50 years. At the same

time the number of nonindustrial land owners is expected to

continue to grow and the average parcel size fall. Between

1997 and 2002, the forest area in major metropolitan areas

increased by 5 percent (Smith et al. 2004). Future urban
Interim Update of the 2000 RPA Assessment 65

Rangeland Products

Numbers of cattle and sheep—Cattle numbers have

historically followed 10-year cycles since the mid-19th century.

The national herd size increased until reaching a maximum of

132 million head in 1975. The latest cycle peaked in 1996 at

103.5 million head (fig. 48).

Per capita consumption of beef and veal has stabilized (fig. 49).

Total demand for red meat in developed countries is projected

to increase because of increased population. The annual

increase through 2020 is expected to be less than 0.5 percent

(Sere and Steinfeld 1996).

Grazing use of Federal rangelands—Livestock grazing on

NFS lands has been relatively stable over the past 30 years

(Mitchell 2000). On these lands, annual permitted cattle

grazing has varied between 8 million and 9 million animal unit

months, or AUMs, (the amount of forage needed to sustain a

1,000-pound cow for 1 month). Permitted sheep grazing during

this time declined from 2 million to 1 million AUMs. Livestock

grazing on BLM lands has been relatively stable at around 10

million AUMs.

Figure 47.—U.S. private growing stock inventory by 

region and species group.

Box 16 (continued)

development will bring still more urban forests and more

people living in closer proximity to the remaining forest

lands (Alig and Plantinga 2005, Alig et al. 2004). The area

of planted pine in the South will continue to expand as U.S.

timber production is concentrated on fewer acres (Alig and

Butler 2004b). Even so, hardwood types will continue to

dominate the forest land base in the South and throughout the

Eastern United States.

For the United States as a whole, and for virtually all regions

and private owner groups, projected softwood inventory in

2050 is higher than estimated levels in 2000 (fig. 47). Growth

exceeds harvest in all these cases despite rising removals over

the projection. Aggregate U.S. private hardwood inventories

also rise sharply by 2050, with continued expansion in the

North offsetting modest reductions in the South.

One of the key determinants of long-term forest growth is

private investment in silvicultural activities. For the South,

the RPA Assessment Update base case projects continued

shifts of private timber land in softwood types toward the

more intensive forms of management for both industrial

and nonindustrial ownerships. In western Washington and

western Oregon, industrial ownerships will continue to shift

lands toward more intensive silvicultural regimes until the

decade 2010–19; by the end of the projection, the structure

of management intensities will return to the mix observed in

the 1990s.
66 Interim Update of the 2000 RPA Assessment

Box 17

Characteristics of private rangeland associated with public land grazing leases—The Western States have experienced tremendous population growth over the past 30 years,

with many of these people moving into previously rural

areas (Theobald 2001). This exurban development of former

rangelands has the potential to significantly affect wildlife

and ecosystem processes (Hanson et al. 2002). Any impacts

of exurban development in the West tend to be aggravated

by the relative positions of public and private lands; that is,

private lands are generally at lower elevation and on more

productive soils than public lands (Scott et al. 2001).

Little is known about the size, distribution, and types of

rangeland occupied by private ranches having Federal

grazing permits or leases, or about the beliefs and attitudes

of public lands graziers. Some observers, however, have

hypothesized that ranches, by their nature of requiring

extensive acreages to produce an agricultural product, act

as protected areas for open space and biodiversity (Maestas

et al. 2003). Public rangelands contribute key parts of the

annual forage requirements for ranches with public grazing

leases. Although research has shown that ranchers would not

want to sell their ranches if they lost their grazing privileges,

such a loss would constitute a major variable in the complex

of factors that influence the maintenance of livestock grazing

in rural areas (Sulak and Huntsinger 2002). Unpublished

results of a pilot study in the southern Rocky Mountains

indicate that private ranches occupy areas that are proximate

to public lands. Thus these lands may not only act to protect

open space and biodiversity, but could also tend to mitigate

ecological and social conflicts between public and private

lands (Mitchell and Wallace 1998).

Figure 48.—Number of cattle and sheep. Figure 49.—Per capita consumption of meat and fish.

200

180

160

140

120

100

80

60

40

20

0

Pounds per capita

1970

198019902000 

Fish Chicken Lamb Pork Veal Beef
Interim Update of the 2000 RPA Assessment 67

Summary

Available measures of productive capacity are very coarse. In

this RPA Assessment Update, we project increasing volumes

of growing stock inventory. The level of timber inventory

depends in part on assumptions about future trade, management

intensity, harvest, mortality and timberland area. The area of

timber land is projected to remain relatively stable, but this

outcome is dependent on assumptions about urbanization and

rural land use changes including parcelization. The timber

growth-removal ratio is projected to continue to be greater

than one for the Nation as a whole for both hardwoods and

softwoods. This outlook is dependent on assumptions about

imports and exports, management intensity and harvest on

timber land. Over the past decade, the sale of forest industry

lands to timber investment management organizations and real

estate investment trusts has increased uncertainties about the

long-term management and disposition of these properties.

Management of these lands has potential to affect the outlook

for plantation area. There is little prospect for better data at

a national scale for nontimber forest products such as wild

mushrooms, berries, and so forth.

The grazing of cattle on Federal rangeland has been relatively

stable during the past several decades, suggesting some measure

of sustainability. Although at lower elevations, and generally

more productive than Federal lands, privately owned rangeland

is threatened by parcelization in some areas of the West.
68 Interim Update of the 2000 RPA Assessment
Interim Update of the 2000 RPA Assessment 69

A basic need to know how and why our forest land and

rangeland ecosystems are changing and to determine the

importance of human influences on these changes will

continue. Forest land and rangeland ecosystems are naturally

dynamic, often changing species composition and abundance

as the ecosystem evolves through succession or reacts to

disturbances such as fire and insects. These dynamics are an

essential ingredient of a healthy ecosystem. Human stresses

on ecosystems include introduced insects, diseases, plants,

and wildlife; altered fire patterns; air pollution; and land use

practices such as timber harvesting and livestock grazing.

Climate change can complicate all these stresses.

Climate Change

Climate change is one of many pressures on forest land and

rangeland ecosystems in the United States encompassed under

the term “global change.” Ecosystems sustain human life by

providing some of the goods and services on which life depends,

including food, fiber, shelter, energy, and other amenities, such

as biodiversity, clean air and water, recycling of elements, and

cultural, spiritual, and aesthetic returns. Ecosystems also affect

the climate system by exchanging large amounts of energy,

water, and greenhouse gases with the atmosphere.

Climate variability and change can alter the structure and

function of ecosystems. These variations and changes in

turn can affect the availability of ecological resources and

benefits, can change the magnitude of some feedbacks between

ecosystems and the climate system, and can affect economic

systems that depend on ecosystems.

Other pressures under the term ‘global change’ include the

human stressors listed above. The deposition of atmospheric

trace gases such as nitrogen oxides, sulfur dioxide, and ozone

reduce vegetation growth. Introduced species, such as plants,

insects, or animals, alter the native ecosystems. Land use

changes such as the conversion of forests to agriculture or

urban area reduce the land area in natural ecosystems as well

as the dynamics of the remaining forest land. While some of

these changes may occur at a faster rate than those resulting

from climate change, particularly in the near term, climate

change has the potential to fundamentally alter the large-scale

distribution of U.S. forest land and rangeland ecosystems, their

species diversity, their productivity, and their ability to supply

ecosystem services.

The energy of the Earth’s atmosphere and the dynamics of

global and regional climates are strongly influenced by the

chemistry of the atmosphere. Carbon dioxide, methane, nitrous

oxides, chlorofluorocarbons, and water vapor are known

collectively as greenhouse gases and have the potential to

warm the atmosphere. The amount of warming is a function of

the ability of these gases to absorb solar radiation (a physical

constant) and the atmospheric concentrations of each gas.

The 2003 concentrations of greenhouse gases are shown in

table 6. For carbon dioxide, methane, nitrous oxides, and the

chlorofluorocarbons, their concentrations since preindustrial

times have increased from 13 percent (nitrogen oxides) to 145

percent (methane). Approximately three-quarters of the carbon

dioxide emissions are from fossil-fuel combustion, the rest

from land use change (Intergovernmental Panel on Climate

Change 2001). Concentrations of carbon dioxide continue to

increase in the atmosphere whereas methane concentrations at

the global scale remained constant from 1999 to 2002.

Recent reports from the Intergovernmental Panel on Climate

Change suggest that human-caused emissions of carbon dioxide

and other greenhouse gases will alter climates and raise global

average temperatures by 1.4 to 5.8 °C by the end of the 21st

century. These emissions are likely to affect weather patterns,

extreme climate events, and the seasonality of weather.

And these changes in weather and climate will alter water

resources, ecosystems, and the social and economic dynamics

of communities. In the United States, average temperature

is projected to rise from 2 to 5.5 oC over the next 100 years.

Projections of precipitation changes vary greatly across the

United States and are more uncertain than the projected

changes in temperature.

Maintenance of Forest and Rangeland Ecosystem Health and Vitality
70 Interim Update of the 2000 RPA Assessment

Over the past 5 years, analysis of long-term trends in the

natural systems has increasingly documented physical and

biological changes. These changes include decreasing mass

of glaciers and Artic sea ice, changes in seasonal dynamics of

snowpack, rising sea levels, changes in temperature-sensitive

events in the life cycle of plants and animals, and changes in

ecosystem productivity.

Recent studies at the global and at the North American spatial

scale have used large-scale patterns of surface temperature

variation and climate models to investigate changes in climate

over the 20th century. Increases in the North American

temperatures observed from 1950 to 1999 were unlikely to be

due only to natural climate variations. Observed trends were

consistent with climate simulations that include increasing

atmospheric greenhouse gases and sulfate aerosols, thus

detecting a human influence on North American climate

(Climate Change Science Program 2004).

Ecosystem impacts—The use of future climate scenarios and

ecological models suggests that the impact of climate change

on U.S. ecosystems could include increases in ecosystem

productivity in the short term and shifts in the distribution of

plants and animals in the long term (Joyce and Birdsey 2000).

As climate changes advance, there are some indications that

there will be increases in disturbances such as forest fires,

drought, and insects (Dale et al. 2001)

Plants and animals have adapted to climate and have been

known to respond to changes in climate on short-term as well

as long-term time periods. Average body shape and size of

animals reflect the adaptation to climate over evolutionary

time periods. Changes in body shape, size and other physical

traits may provide better adaptation to local climate (Parmesan

and Galbraith 2004) and could occur in short time periods

responding to changes in the local climate. The phenology

of important events in a plant or animal’s life cycle may be

affected by climate. These events include the onset of spring

growth, timing of migration, timing of breeding, and spring

insect emergence, for example. Changes in the geographic

distribution of plants and animals have been documented in

paleoecological studies during and after the last glaciation in

North America (Delacourt and Delacourt 1993). Recent efforts

that have associated species diversity patterns with attributes

of climate have confirmed what these paleoecological studies

have suggested. Namely, that the diversity of trees, birds,

mammals, amphibians, and reptiles may change dramatically

under projected changes in climate (Hansen et al. 2001). At the

ecosystem level, the relationship between ecological processes

such as nutrient cycling and decomposition is known to be

sensitive to moisture and temperature.

Table 6.—Greenhouse gases in the atmosphere.

Atmospheric concentration1 Atmospheric Atmospheric Increased radiative

prior to 1750 concentration2 2003 lifetime (years)3 forcing (W/m2)

4

Carbon dioxide 280.0 ppm 374.9 ppm Variable 1.46

Methane 730.0 ppb 1852.0 ppb 12 0.48

Nitrous oxide 270.0 ppb 319.0 ppb 114 0.15

1

 Following the convention of IPCC (2001), inferred global-scale trace-gas concentrations prior to 1750 are assumed to be practically uninfluenced by human 

activities such as increasingly specialized agriculture, land clearing, and combustion of fossil fuels. 

2

 For most gases, concentrations for the year 2003 are given, as indicated more specifically in the footnotes below. Estimates for 1998, from IPCC (2001), are 

given for CHF3, C2F6, and SF5CF3. The current (2002) concentration of SF5CF3 is probably around 0.16 parts per trillion. Atmospheric concentrations of some 

of these gases are not constant throughout the year. Global annual arithmetic averages are given. 

3

 The atmospheric lifetime is defined as “the burden (Tg) divided by the mean global sink (Tg/yr) for a gas in a steady state (i.e., with unchanging burden)” (IPCC 

2001: 247).

4

 Increased radiative forcing is the change in the rate at which additional energy is made available to the Earth atmosphere system over an “average” square 

meter of the Earth’s surface due to increased concentration of a “greenhouse” gas, or group of gases, since 1750. Energy is measured in joules; the rate at which 

it is made available is in joules/second, or watts; hence, radiative forcing is measured in watts per square meter (W/m2).
Interim Update of the 2000 RPA Assessment 71

Box 18

Sea-level rise—Within the United States, 51 percent of the

2000 population lives within 80 km (50 miles) of an ocean or

the Great Lakes coasts, whereas this area accounts for only

13 percent of the continental U.S. land area (Rappaport and

Sach 2003). Increasingly, coastal areas are being developed,

altering the natural systems along the coast lines. Ecological

services provided by these coastal ecosystems include habitat

for terrestrial and aquatic organisms, attenuation of waves

and storm surge impacts, and the nutrient export to stimulate

estuarine and near-shore productivity.

Sea-level rise globally over the past 100 years has been

estimated to be between 10 and 25 cm (3 to 10 inches)

(Shriner et al. 1998). Within the United States, sea-level rise

has been 2.5 to 3.0 mm/year along parts of the U.S. Gulf

coast and along the Atlantic coast south of Maine (Shriner et

al. 1998). Along the Louisiana coastline, a combination of

natural and human-induced processes (in addition to climate

change) is resulting in land subsidence (Burkett et al. 2005).

The Alaskan coast is experiencing a postglacial rebound and

sea level appears stable.

A potentially warming climate will warm the oceans and will

increase the melting of the glaciers. Sea-level rise occurs

through the thermal expansion of the ocean, glacial melt, and

ice-cap decline.

Given scenarios for climate change, global mean sea level is

projected to rise by 50 cm (19.7 inches) above today’s levels

by 2100, with an uncertainty range of 20 to 86 cm (7.9 to

33.9 inches) (Shriner et al. 1998). For the North American

Atlantic ocean coastlines, the sea-level rise may be higher

than the global average, reflecting the higher historical rates

of sea-level rise in this area. Similarly, the sea-level rise

along the Pacific Coast of North America is likely to be

lower than the global average, reflecting the lower historical

rates there. Even if concentrations of greenhouse gases were

stabilized at the 2000 levels, the atmosphere would continue

to warm by another half degree C from the current levels

of greenhouse gases in the atmosphere (Meehl et al. 2005).

This further warming of the atmosphere would result in a

sea-level rise of 10 to 18 cm (3.9 to 7.1 inches), from thermal

expansion of the oceans only (Meehl et al. 2005).

Coastal ecosystems in the United States vary from coastal

grasslands, salt marshes, mangrove forests, agricultural land

and lowland forests. Sea-level rise influences these coastal

ecosystems through increases in tidal flushing in estuaries

and storm surges over low-lying coastal landforms, processes

which alter the salinity levels, sediment transport and other

coastal processes that maintain these ecosystems (Burkett

et al. 2005). In addition, higher tides result in saline water

moving farther inland in streams and rivers, increasing the

salinity exposure to those riparian systems and salt water

intrusion to water supplies.

Shriner et al. (1998) reported that a 50 cm (19.7 inches) rise

in sea level would inundate approximately 50 percent of

North American coastal wetlands in the 21st century. This

50 cm (19.7 inches) rise could also inundate 8,500 to 19,000

km2 (3,282 to 7,336 square miles) of dry land (Shriner et al.

1998). This dry land includes forests and agricultural land,

mainly in mid-Atlantic and Southeastern United States.

Coastal vegetation varies in its tolerance to saline conditions,

resulting in a zonation of vegetation along the coastlines

where plants with high tolerance experience the saline water

and plants with lower tolerance are further from the coast

and high tide marks. In the Big Bend region of Florida,

forests are found on mounds above the mean higher high

water (the higher of the two tides each day) (Burkett et al.

2005). When sea level rises, trees are unable to regenerate

as the seedlings fail in high salinity conditions and under

high water conditions (Williams et al. 1999). Burkett et al.

(2005) noted that the loss of coastal systems may appear to

be incremental however, some coastal systems may not show

a response until an intrinsic threshold is reached, resulting in

large-scale loss of the coastal system.
72 Interim Update of the 2000 RPA Assessment

Understanding of recent changes in climate comes from the

analysis of large spatial-scale patterns over long periods of

time. Attribution of any biological response to climate change

is complicated because short-term and local biological changes

are strongly influenced by factors such as land use. As with

the detection of the climate change signal, the underlying

biological signal from climate change will be teased out

only with analyses that seek systematic trends, over time,

across large spatial regions, and across many diverse species

(Parmesan and Galbraith 2004). Examples of existing studies

include an analysis of the range and phenological patterns of

1600 species across the globe (Parmesan and Yobe 2003);

the timing of initiation of breeding in tree swallows (Dunn

and Winkler 1999), and the range of the Edith’s checkerspot

butterfly (Parmesan 1996).

Socioeconomic impacts—Climate variability and change

can profoundly influence social and natural environments

throughout the world, with consequent impacts on natural

resources and industry that can be large and far-reaching. For

example, seasonal to interannual climate fluctuations strongly

affect agriculture, the abundance of water resources, and the

demand for energy, while long-term climate change may

alter agricultural productivity, land and marine ecosystems,

and the goods and services that these ecosystems supply. At

the national level, where climate change was projected to

induce forest productivity increases, consumers were found

to benefit but not producers. Projections of yield decreases

had the opposite effect (Alig et al. 2004). Adaptation in the

forest sector and in the agricultural sector could limit these

effects. Options in forestry include land market adjustments,

interregional migration of production (e.g., northerly migration

of productive capacity), substitution in consumption between

wood and nonwood products (reflected in overall growth in

wood products use) and between sawtimber and pulpwood, and

alteration of stand management (Alig et al. 2004).

Practices that increase carbon sequestration in ecosystems or

reduce emissions are seen as ways to mitigate these potential

impacts. The United States currently administers a variety

of voluntary, regulatory, or incentive-based programs on

energy efficiency, agricultural practices, and greenhouse gas

reductions. The voluntary greenhouse gas reporting program

allows for the reporting of practices that increase carbon

sequestration or reduce emissions. Many western parks are

implementing measures such as using alternative fuel vehicles,

such as converting diesel fleets to 20 percent biodiesel or

promoting bus shuttle systems, which helps address air quality

concerns in pristine environments. The National Park Service

Climate Friendly Parks Initiative reviews park activities to

reduce emissions. In 2005, the Arapahoe Basin Ski Area in

Colorado had a “Be Cool and Carpool” program that offered

discounted lift tickets to those who arrived with four people or

more in one vehicle.

Meanwhile, U.S. annual production of fuel ethanol (mostly

from corn grain) climbed from 1.6 billion gallons in 2000 to 3.9

billion gallons in 2005 (Renewable Fuels Association 2006).

At present, ethanol production consumes about 15 percent

of U.S. corn grain harvest, and future increases in output of

ethanol may begin to impact corn prices more significantly in

the future. If so, alternative feedstocks for ethanol production,

including lignocellulosic materials such as wood, may begin to

be used on a large scale for ethanol production.

Forest Health and Vitality

Air pollution—Air pollution exposure has generally been

highest in the East (Coulston 2004). Annual estimates of sulfate

deposition for forested areas decreased across all regions from

1994 through 2000. In the East, about 50 percent of the forest

was exposed to sulfate deposition of more than 13.4 pounds per

acre per year for the period (fig. 50). Nitrate deposition rates

were lowest in the Pacific Coast and Rocky Mountain regions.

In those areas, approximately 84 percent of the forest received

less than 4.2 pounds per acre per year from 1994 through 2000,

as compared with the East where only 2 percent of the forest

received this amount. Ozone exposure was highest across the

South and in southern California; however, little or no ozone

injury to plants was recorded on most ozone biomonitoring

plots (fig. 51). In the North and South, about 77 percent of the

biomonitoring plots received little or no injury. In the Pacific

Coast and Rocky Mountain regions, 97 percent and 100 percent,

respectively, of the biomonitoring plots had little or no injury

from ambient levels of tropospheric ozone. Only a small portion
Interim Update of the 2000 RPA Assessment 73

Figure 51.—Percent of ozone biomonitoring plots with low, 

moderate, or severe foliar ozone injury.

Figure 52.—Average annual mortality as a percent of 

growing stock inventory.

Mortality—Mortality is one indicator of health. Average

annual mortality as a percent of timber inventory has generally

been between 0.5 and 0.8 percent (fig. 52). Mortality is a

coarse-filter measure of ecosystem condition. If dead and dying

trees are salvaged and used between inventories, this volume is

not reflected as mortality in timber inventories. Thus, relatively

large losses of volume can occur due to disturbance agents that

are not measured as mortality.

The Forest Service Forest Health Protection Program has

developed estimates of the area of forests where increased

mortality rates from insects and diseases are expected to occur

(Lewis 2002). These rates were termed to be at risk because

there was an expectation of at least 25 percent mortality over

“normal” mortality rates from insects and pathogens over

the next 15 years. Twenty-six insects and pathogens were

evaluated using current survey data, models, and expert opinion

to estimate forested areas at risk.

The Forest Service Forest Health Protection Program found

an estimated 58 million acres or 8 percent of the forested area

in the United States to be at risk. Gypsy moth in the East, root

diseases in the West, southern pine beetles in the South, and

bark beetles in the West were responsible for 66 percent of the

total area at risk. In the North, 8.6 percent of the forested area

was estimated to be at risk; 7 percent in the South; 13.6 percent

in the Rocky Mountain region, and 5.8 percent in the Pacific

Coast region.

Figure 50.—Cumulative distribution functions of forest 

subject to specific levels of wet sulfate deposition (1994 to 

2000).

of plots, mostly in the North and South, had severe foliar injury.

Results from multivariate analysis showed that oak-hickory and

loblolly-shortleaf forest type groups were generally exposed to

more air pollution than other forest types. Conversely, western

white pine and larch forest type groups were exposed to less air

pollution than all other forest types. Currently, it is not known

if the specific levels of sulfate, nitrate, and ammonium deposition

reported cause large-scale negative effects on forest ecosystems

even though smaller scale effects have been observed, such as

on high-elevation spruce-fir forests.

120

100

80

60

40

20

0

0.036

3.5

6.96

10.4213.8817.3420.8124.2727.7331.1934.65

Percent

West sulfate (pounds per acre per year)

North Pacific Coast Rocky Mountain South

120

100

80

60

40

20

0

Little or 

no Injury

Low Injury Moderate 

Injury

Severe 

Injury

National forest Forest industry Rocky Mountain South

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

1952 1962 1976 1986 1996 2002

Softwoods Hardwoods Total
74 Interim Update of the 2000 RPA Assessment

Box 19

Bringing climate into natural resource management— 

Increasing concerns about climate have put the issue on the

agenda of some natural resource managers in the Western

United States and they are using institutional processes to

develop management actions to address climate change.

In listening to more than 70 natural resource managers

and professionals in the Western United States, Joyce and

Laskowski (2006) found that understanding the role that

climate plays in the natural environment was an important

step in developing management activities to address climate

variability and change. In past natural resource management

or planning, climate was often assumed to be static over

the period of interest, so that the management focus was on

managing the relationships between habitat changes or natural disturbances and the natural resource of interest. Today,

consideration of climate, if any, is typically linked with a

current resource management goal (e.g., improved grazing or

hydropower capacity), concern about the sustainability of the

natural resource, and recent climate variability.

Natural resource managers from Federal agencies, State

agencies, and nongovernmental organizations are bringing

the consideration of climate into the management arena

through institutional processes such as assessment,

monitoring, focused research, education, planning,

field-based activities, and mitigation. A diverse array of

assessments initiated by resource agencies or organizations

have been aimed at describing and quantifying potential

impacts such as the vulnerability of coastal ecosystems

to sea level rise, the potential impact on resources and

recreation within national parks, and the risk to economies

in the Southwest. Long-term monitoring of climate change

indicators to detect changes in the natural resources has

been initiated by natural resource agencies, such as the

NPS in the United States and Parks Canada in Canada.

A variety of indicators are being considered such as

weather, ice-free time in lakes, glacier photography, tree

encroachment, and indicator species such as butterflies.

Natural variability of climate such as drought (both the

temperature and the moisture aspects) and intense rainfall

events were phenomena that managers were addressing in

their management plans.

Natural resource managers included the consideration of

climate change only when scientifically accepted quantitative relationships between climate and a specific natural

resource (e.g., water) were available and when applications

were available that could easily be used within the manager’s

current planning or management framework. Managers benefiting from partnerships with climate-focused organizations,

extension staff, and/or scientists within their geographic

areas were able to incorporate consideration of climate variability and change into management planning processes.

Monitoring and recording of disturbances in our forests has

taken place only over the past 100 to 150 years, depending on

the disturbance agent. Observations are lacking for more distant

timeframes, precluding us from knowing with certainty what

the preceding historical conditions and trends may have been.

Analyses of tree rings and other materials do provide clues

to estimate some past conditions. Ciesla and Mason (2005)

compared data for conditions for various disturbance agents

in the period 1996–2000 with available data for the periods

1800–50 or 1979–95, depending on the disturbance agent. By

definition, impacts from exotic insects, diseases, and plants are

outside the natural range of variation of our forest ecosystems.

The following highlights the extent of disturbance by various

agents. The range of variation for some disturbance agents in

existing ecosystems is being established by the Forest Service

Forest Health Monitoring (FHM) Program.

A potentially grave threat to coastal forests in California

and Oregon, and possibly the rest of the country, has been

the outbreak of an emerging generalist root rot pathogen,

Pytophthora, first discovered in Europe as the cause of the

Irish potato famine. Pytophthora has been causing significant

mortality in various species of oaks, cedar, and redwood.

(See http://nature.berkeley.edu.comtf/ for more information).
Interim Update of the 2000 RPA Assessment 75

Various species of this exotic pathogen have also impacted

southern oaks from South Carolina to Texas as well as trees in

the Ohia forests in Hawaii.

Area of forest affected by insects and diseases—For the

most part, outbreaks of native insects and diseases have been

episodic with eventual collapse of populations/infestations by

natural agents or fires. Ciesla and Mason (2005) suggest that

acreage affected by the following indigenous insects may have

exceeded their historical range of variation during the period

1973 through 1997, in the indicated year: southern pine beetle

(1986 and 1995); mountain pine beetle (1981); spruce beetle

in Alaska (1996); spruce budworm (1978); spruce budworm in

Alaska (1997); western spruce budworm (1986), and Douglasfir tussock moth (1973). Similarly for native diseases, Ciesla

and Mason (2005) suggest that dwarf mistletoes, fusiform

rust, root diseases in portions of northern Idaho and western

Montana, oak decline in Arkansas, and oak wilt in Texas since

the 1970s may have been at levels exceeding the historical

range of variation. Data for annual forest and insect conditions

are maintained by the Forest Service at http://www.fs.fed.us/

foresthealth/pubsindex.shtml.

Invasive Plants and Animals

Forests can be adversely affected by invasive plants and animals.

Throughout the landscape, plants and animals introduced from

other countries can create problems and push out some native

species. Some foreign plants and animals have no natural

predators to stop them. Exotic weeds can take hold when new

roads are installed as part of the expanded developed area in the

United States (Alig et al. 2005) or when homes are built.

Human disturbances have also contributed to problems caused

by native species such as raccoons, jays, and crows spreading

into habitats where they normally do not occur in harmful

numbers. One reason for that spread is human disturbance

of natural systems. For example, raccoons in the developing

lands of Shenandoah, Virginia, are now found in moderate to

high densities (more than 10 per square mile) in 96 percent of

counties, compared with only moderate densities in 43 percent

of the counties in the 1970s. Raccoons not only are a predator

of ground-nesting birds but also are vectors for rabies.

Protected open space lands give communities a better chance

of keeping invaders under control. For example, where open

spaces remain intact, controlling exotic weeds is a simpler task.

Also, high-density developments sharing a common large tract

of open space can result in a similar outcome—where weed

control is part of the land covenant.

More than 4,500 exotic free-living species are in the United

States—some 2 to 8 percent of plants, insects, and pathogens

are introduced. Approximately 19 of the 70 major insect pests

found in the United States are exotic.

High-profile exotics include Dutch elm disease, chestnut blight,

white pine blister rust, Port-Orford-cedar root disease, European gypsy moth, hemlock woolly adelgid, and beech bark disease. These infestations can have effects extending well beyond

the loss of timber volume. For example, loss of hemlock from

eastern forests as a result of the hemlock woolly adelgid would

impact riparian areas where hemlocks help regulate water temperature and wildlife species that depend on hemlock stands for

shelter, nesting, and foraging habitat. Dutch elm disease had a

large and adverse impact on urban forested ecosystems.

One 1994–95 study showed that a significant part of the total

flora is composed of invasive plant species. The number of

invasive plant species was highest (greater than 10 percent of

the total flora) in areas of the North, and in areas of the Pacific

Coast region. Invasive plant species accounted for 25 percent

of the California cover (Stapanian et al. 1998).

The scope, impact, and trends of invasive plants are outlined

in a fact book by the Federal Interagency Committee for the

Management of Noxious and Exotic weeds (Westbrooks 1998).

Among the most worrisome exotic weeds found on U.S. forests

and rangelands are leafy spurge, knapweeds, and star thistle,

Canada and musk thistles, salt cedar, cheat grass, mile-aminute, and purple loosestrife (Mitchell 2000).

Hypotheses on why invasive species expand so aggressively

include the presence of fewer natural enemies (insects and

disease), less competition from native species, and native

species that are vulnerable to chemical attack by the invaders

(called allelopathy). The knapweeds (Centaurea spp.) found
76 Interim Update of the 2000 RPA Assessment

Figure 53.—Area burned by wildfire.

on rangelands are exceedingly successful in completely

dominating habitats because of allelopathy. Recent theoretical

work by ecologists has concluded that invasive species tend to

rely on two related mechanisms to occupy new sites—release

from natural enemies and being adapted to make use of high

levels of resources. Native species adapted to increased

resource availability tend to be contained by natural enemies.

Wildfire—The frequency and scope of wildfire have changed

dramatically over time (fig. 53). Fire suppression resulted

in relatively stable areas burned from the 1950s through the

1970s. During the 1980s, the area burned by wildfires in the

West began to increase again, due in part to unprecedented

success of fire suppression and its effects on forest conditions.

Fire suppression led to increased forest density and biomass,

changes in forest composition and the resulting increases in

insect and disease susceptibility and mortality, and the resulting

buildup of fuels (Hill 1998).

Forest condition class—Historical (pre-European

colonization) fire regimes were reconstructed from tree ring

analyses and fire scars (USDA Forest Service Fire Sciences

Laboratory 1999a, 1999b) to identify areas of relatively

high change in forest condition. Current condition classes

categorize departure from the historical fire regimes based on

five ecosystem attributes: Disturbance regimes, disturbance

agents, smoke production, hydrologic function, and vegetative

attributes. Current condition class 1 represents a relatively

small deviation from ecological conditions compatible with

historical fire regimes. Condition class 2 is a deviation from

ecological conditions compatible with historical fire regimes

that would require some silvicultural management to restore

conditions compatible with historical fire regimes. Current

condition class 3 represents a major deviation from the

ecological conditions compatible with historical fire regimes

that would require a major effort such as harvesting and

replanting to restore.

Seventy-three percent of the forested area in the North was

classified as condition class 2 or 3. Most of the forested area

in the South (70 percent) has ecological conditions compatible

with historical fire regimes and is classified as condition class 1.

Eighty-six percent of the forested area in the Pacific Coast region was classified as condition class 2 or 3, as was 78 percent

of the Rocky Mountain region.

Wildlife—Wildlife populations can increase to the point of

becoming threats to the health and vitality of forest land and

rangeland ecosystems. For example, in some portions of the

East, white-tailed deer have reached numbers that are causing

damage to plant community structure and forest regeneration

(Ciesla and Mason 2005). Excessive deer browsing also has

been shown to reduce nesting areas for songbirds, change the

composition of small animals, reduce winter food for turkeys,

and reduce cover for black bear and ruffed grouse.

Rangeland Health and Vitality

Traditional methods for monitoring rangeland condition have

focused on vegetation and soil dynamics at the site level. Other

indicators of rangeland health and vitality are more appropriate

at regional and national scales. These include (1) area and

percent of rangeland affected by processes like invasive weeds,

fire, and grazing outside their range of natural vegetation,

(2) deposition of air pollutants, and (3) area and percent of

rangeland with diminished biological components indicative

of changes in fundamental ecological processes. Currently,

little is known about ranges of natural variation of disturbances

at multiple scales, and no national inventory captures these

metrics. Little theory or agreement exists on how indicators

should be integrated for assessing changes in ecological

processes at a broad scale.
Interim Update of the 2000 RPA Assessment 77

Summary

The forest resources of the United States have always

been affected by insects, diseases, fire, and other natural

disturbances. European settlement brought land clearing, new

domestic animals, new species of plants and animals, and other

sources of disturbance beyond the range of historical variation

for North American ecosystems. Human activities over the

past three centuries have forever changed the nature of some

forested ecosystems in the United States.

Pre-European conditions will never again exist for the bulk of

U.S. forest land and rangeland ecosystems. Much of the forest

in the North and West would require at least some silvicultural

management to restore conditions compatible with historical

fire regimes.

The range of natural variation in existing ecosystems has yet

to be established in terms of disturbance, pollutants, and the

functioning of fundamental processes. The FHM Program

of the Forest Service is establishing a baseline to be used

to evaluate changes in forest ecosystem health and vitality.

As more States are included, results from this program will

provide the basis for more wide-scale statements regarding

ecosystem health and vitality. Until such a baseline exists,

episodic outbreaks and damage from insects and disease,

fuel buildups, and other disturbances will continue to be of

concern and will be the source of speculation about their role

in ecosystem health and vitality. Globalization of the world

economy will mean more travel, trade, and opportunities for

the spread of exotic insects and diseases. Fragmentation of

landscapes and changes in land use will continue to stress

forest health and increase the likelihood of invasion by exotics.

Air pollution remains a threat to many forest and high-elevation

alpine and subalpine ecosystems. Although sulfate levels are

declining, regional haze, ozone, and nitrogen deposition have

increased for some areas and pose increasing problems for

sensitive forest, range, and aquatic ecosystems. In some areas,

wildlife populations have increased to the point of being threats

to forest land and rangeland ecosystem health and vitality.

The possibility of climate change adds new dimensions to the

evaluation of forest land and rangeland health and vitality.

Climate change may lead to land cover and land use changes,

increases in atmospheric pollutants such as ozone and nitrous

oxides, and potential expansion of invasive plants and animals.
78 Interim Update of the 2000 RPA Assessment
Interim Update of the 2000 RPA Assessment 79

Condition of Forest Soil

There is little data but research-scale data regarding forest soil

erosion, forest soil organic matter and other soil chemical properties, forest soil compaction or changes in soil physical properties, and the area of forest land experiencing an accumulation

of persistent toxic substances (O’Neill and Amacher 2004a,

2004b, 2004c, 2004d). The following excerpts available information as reported in the four papers by O’Neill and Amacher.

Data from the Natural Resources Conservation Service State

Soil Geographic (NRCS STATSGO) database and the Forest

Inventory and Analysis (FIA)/FHM soil indicator program suggest that the potential for the most forest soil erosion is in the

southern Appalachian Mountains of West Virginia, Kentucky,

North Carolina, and Virginia—an area of erodible soil, high

relief, and intense rainfall—and in mountainous areas in the

northern Rocky Mountains and the Cascades Range (fig. 54).

Soil Organic Matter and Other Soil Chemical 

Properties

Analysis of the NRCS STATSGO data indicates a rough latitudinal gradient in soil organic matter contents, with low soil

organic matter contents in the warmer southern portions of the

country and higher soil organic matter contents becoming more

prevalent toward the Northern United States. General patterns

of carbon distribution based on FIA/FHM data are similar to

those derived from the NRCS STATSGO data and indicate

highest organic carbon concentration in upper mineral soils of

New England, upper Minnesota, and the Pacific Northwest.

Soils in regions receiving higher precipitation, such as the

Eastern United States, are more acidic than soils in arid regions

(fig. 55). In these areas, high rainfall tends to leach base cations

(e.g., calcium, magnesium, and potassium) from the surface of

soil particles, resulting in increased acidity.

Figure 54.—Modeled erosion limitation ratings derived 

from State Soil Geographic database of the Natural 

Resources Conservation Service. 

Figure 55.—Modeled mean soil acidity in the upper 

mineral layer of woodland soils derived from the State 

Soil Geographic database of the Natural Resources 

Conservation Service.

Conservation and Maintenance of Soil and Water Resources
80 Interim Update of the 2000 RPA Assessment

Data from the NRCS STATSGO database and the FIA/FHM

soil indicator program can provide some general insights

into the susceptibility of different regions to soil compaction

or change in soil physical properties resulting from human

activities. Although soils throughout much of the Eastern

United States are rated as more susceptible to physical

disturbance from management practices (fig. 56), evidence of

surface soil compaction above trace levels was not found on 86

percent of FIA/FHM plots measured in 1999–2000.

The accumulation of persistent toxic substances in the soil

depends upon a large number of site-specific factors, including

proximity to the source, the composition and chemistry of

the soil (e.g., acidity, organic matter content, clay content),

drainage, and local climate. For this reason, pollutant

accumulation can only be measured at the local level and

cannot be inferred from deposition or soil properties alone.

At present, no national-scale monitoring programs exist for

accumulation of persistent toxic substances on forest land.

O’Neill and Amacher (2004d) discuss an experimental

approach to determination of the potential susceptibility of

forest lands for accumulation of toxic substances.

Condition of Water Flowing From Forest Land

No national-scale monitoring programs are in place to assess

the various characteristics of water flowing from forest land.

Water monitoring stations are generally placed at the bottom

of watersheds that have a variety of land uses. For example,

within a watershed may be forest cover, agricultural land

uses, and urban settings. The water monitoring stations cannot

differentiate the source of water in samples.

In an attempt to isolate samples of water draining from forested

areas, the Heintz Center worked with the U.S. Geological

Society and its National Water Quality Assessment program to

determine nitrate loadings in streams coming from watersheds

that are predominately forested (H. John Heinz III Center for

Science, Economics, and the Environment 2002). The Federal

standard for drinking water for the protection of human health

is 10 parts per million of nitrate. Ninety-seven percent of forest

stream sites had nitrate concentrations below 1 part per million,

more than three-fourths had concentrations of less than 0.5

parts per million, and more than one-half had concentrations of

less than 0.1 parts per million.

Brown and Binkley (1994) found that the quality of water

draining forested watersheds is typically the best in the Nation,

whether the forests are left untouched or managed. Water

quality problems on forest land are highly variable over space

and time. Relatively few forest areas of the country, if carefully

managed, are prone to troublesome pollutant yields. Forest

practices, however, are sometimes poorly implemented, leading

to degradation of water quality. Sediment loads in streams are

the most widespread water pollution problem in forests and are

especially associated with poor road design and maintenance.

Forest practices generally have little impact on oxygen levels or

on dissolved solids. Nitrate generally is the only ion of critical

interest in relation to forest practices. Harvesting markedly

increases nitrate concentrations in the chapparal and northern

hardwood areas. Application of nitrogen fertilizers may cause

stream nitrate levels to peak at high concentrations. Buffer

strips along streams can alleviate the effects of harvesting on

water temperature.

Figure 56.—Modeled equipment limitation ratings derived 

from the State Soil Geographic database of the Natural 

Resources Conservation Service.
Interim Update of the 2000 RPA Assessment 81

Summary

Agencies such as the U.S. Geological Survey that monitor

water quality tend to locate monitoring stations in areas with

real or perceived water quality issues. The general lack of

data for the characteristics of water draining from forested

lands may suggest that, although there may be local problems,

little basis exists for developing issues at a national scale.

Regulations embodied in best management practices acts in 43

States generally have as one objective the protection of water

quality (Ellefson et al. 2005).

Agencies charged with monitoring soil conditions also place

added emphasis on land use types more at risk to disturbances.

For example, the NRCS monitors erosion on agricultural lands,

but not on forest lands. Soil erosion and compaction following

forest management activities depend to a large degree on how

the activity is implemented. Few data are available at a national

scale for the condition of forest soils. The Forest Service FHM

Program collects some data on forest soils. Initial data collected

in 1999–2000 indicated that 86 percent of 2,006 plots had only

trace levels of soil compaction. Soil compaction may be a serious problem on a local scale, however, as indicated by the high

proportion of disturbance reported for some individual plots.

Until systematically collected data are available at a national

scale, little basis exists for developing a national statement

on management and policy implications for conservation

and maintenance of forest land and rangeland soils and water

draining from them.
82 Interim Update of the 2000 RPA Assessment
Interim Update of the 2000 RPA Assessment 83

Forests contribute to global carbon cycles in at least two ways.

First, carbon is retained in forests and in forest products as

part of the larger cycle of carbon through the land, water, and

atmosphere. Secondary emissions of carbon to the atmosphere

are reduced to the extent that wood products production and

use causes less fossil fuel carbon emissions than production and

use of substitute products.

Carbon Retained in Forests and Forest 

Products

The accumulation of biomass as living vegetation, debris, peat,

and soil carbon is an important forest process related to the

health and vitality of the forest. Land management activities

influence the uptake and release of the carbon stored in forests.

Carbon is also stored in the atmosphere and the oceans as well

as in vegetation. Because carbon dioxide is a greenhouse gas

with the potential to warm the atmosphere, identifying the

role of forests in storing and releasing carbon is important in

determining changes in atmospheric carbon. Incorporation of

carbon into vegetation is the fastest process whereas transfer to

the soils and the ocean may operate on a time scale spanning

centuries.

In the Intergovernmental Panel on Climate Change carbon

budget for the globe, emissions from fossil fuel combustion

and cement production are the larger of the carbon sources

identified (table 7) (Intergovernmental Panel on Climate

Change 2001). Land use change in the Tropics is a flux into the

atmosphere and there is a residual terrestrial sink.

The carbon balances shown in figure 57 reflect an accounting

for net annual growth and use of timber in the conterminous

United States (Heath and Smith 2004). Forests in the United

States have acted as carbon sinks at least since 1953 when

data first became available. Thus, carbon has accumulated

over time, mainly in aboveground live trees. Significant

regional differences in past and projected carbon storage reflect

Table 7.—Annual average anthropogenic carbon budget for 1980 to 1989. CO2 sources, sinks, and storage in the atmosphere 

are expressed in GtC/yr.

CO2 sources

(1) Emissions from fossil fuel combustion and cement production 5.5 + 0.5

(2) Net emissions from changes in tropical land use 1.6 + 1.0

(3) Total anthropogenic emissions = (1) + (2) 7.1 + 1.5

Partitioning among reservoirs

(4) Storage in the atmosphere 3.3 + 0.2

(5) Ocean uptake 2.0 + 0.8

(6) Uptake by Northern Hemisphere forest regrowth 0.5 + 0.5

(7) Inferred sink: 3 – (4 + 5 + 6) 1.3 + 1.5

Maintenance of Forest Contributions to Global Carbon Cycles

Figure 57.—Carbon pools (Mt) on forest land in the 

conterminous States.
84 Interim Update of the 2000 RPA Assessment

long-term changes in land use and harvesting. Millions of

acres of forests in the Northeast have regrown on abandoned

agricultural land, causing a steep historical increase in carbon,

including a substantial buildup on carbon-depleted soils. As

these forests mature, the rate of carbon buildup is expected to

slow substantially.

The historical pattern is similar in the South Central States,

but the more intensive utilization of southern forests for wood

products has already leveled past gains as growth and removals

have come close to balancing. In the Pacific Coast States,

carbon stocks are expected to increase after a recent decline,

mainly due to reduced harvest projections as more forest land

has been reserved from timber production.

The half-life of carbon in products varies from 1 year for paper

(except free-sheet used in books) to 100 years for wood used in

new single-family homes. Carbon consumption in 1910 was not

exceeded until 1990 (fig. 58). In 1990, some 18 percent of the

carbon consumed was added to products in use and 23 percent

was added to landfills. About one-half was burned for energy,

presumably offsetting fossil fuel or other material that would

have been burned.

Forests in the United States are a sink for carbon in that more

carbon is sequestered than is emitted. In terms of annual flux,

the change in carbon stored in forests amounted to 82 percent

of the change in the stock of carbon in 1990.

Carbon Emissions Avoided With Production 

and Use of Wood Products

The production and use of wood products in end uses results

in emissions of carbon to the atmosphere. To the extent that

wood products are used in place of other products (e.g., steel

and concrete, or plastics) that generate even larger carbon

emissions, it is beneficial to use wood products rather than

other products. One major end use that uses wood, steel, and

concrete is residential housing. Wood (versus steel or concrete)

is used to make 99 percent of roofs, 91 percent of walls, and 69

percent of floors (Wood Products Council 1999).

A life cycle analysis of the emissions associated with

production and use of wood versus steel and concrete in

housing has found that the global warming potential (for gases

emitted) for typical houses is 25 percent to 30 percent greater

when steel or concrete is used in place of wood in floors

and walls (Lippke et al. 2004). The global warming impact

associated with production and use of products for housing

may be further reduced if wood is used for more components of

walls and for exterior siding in place of alternate materials.

In the future, forests and tree plantations may contribute to

global carbon cycles in a third significant way, if biomass

fuels—such as cellulosic ethanol—displace significant

volumes of fossil fuels. Cellulosic ethanol production is

nearing commercial development and is favored by recent

shifts in the global price of oil (from the $20 to $25 per barrel

range of recent decades to a level above $60 per barrel) (U.S.

Department of Energy Biomass Program, http://www/.eere.

energy.gov/biomass). If the global oil price shift is, as some

now suggest, a structural change due to long-run shifts in the

global oil supply-demand balance, then large-scale cellulosic

ethanol production may become a reality which could also

offset fossil fuel carbon emissions.

Figure 58.—Net changes in carbon in harvested wood 

products pools (Mt per year) for the United States, including 

carbon in net imports, from 1910 to 1997.
Interim Update of the 2000 RPA Assessment 85

Summary

Growth of forests in the United States has exceeded removals

at least since 1952; earlier data are not available. Thus, U.S.

forests have been a carbon sink—absorbing more carbon than

they release. With the advent of sealed landfills in the 1980s,

the amount of carbon stored in products increased, especially

for paper and other fiber-based products. The annual rate of

carbon accumulation in landfills and products in use is projected to increase from 65 million tons in 1990 to 83 million tons

in 2040. This change is due entirely to the increasing rate of accumulation in landfills (table 8). Further guidance forthcoming

on green house gas inventories and carbon reporting expected

from the Intergovernmental Panel on Climate Change may

lead to changes in carbon accounting because of reporting on

all greenhouse gases, gross versus net changes in carbon, and

representation of land area. Carbon management technology

is emerging. Forests and rangelands can be part of the solution

to reducing atmospheric carbon dioxide and other greenhouse

gases. Production and use of wood products in place of alternate products can reduce carbon emissions and their associated

contribution to global warming. In the future, biomass grown

for cellulosic ethanol production, such as crops, may further

offset carbon emissions from fossil fuels.

Table 8.—United States net carbon accumulation, emission, net imports, and drain from the atmosphere by year.1

Net carbon flux (Tg)

1990 2000 2010 2020 2030 2040 

Change in forests, CIC 274 189 192 176 166 161

Change in products in use, P 26.02 24.99 24.51 25.58 24.27 22.86

Change in landfills, L 33.38 32.48 39.37 42.53 46.89 50.74

Wood burning, WB 74.38 88.07 96.58 102.83 109.27 118.86

Emitted CO2, ECO2 11.43 14.02 14.83 15.77 16.49 16.98

Emitted CH4 from landfills, ECH4 0 0.23 0.5 0.61 0.62 0.55

Change in stock of carbon2 333.40 246.47 255.88 244.11 237.16 234.60

Net imports of wood products,

 paper, and paperboard (I-3) 2.23 3.26 3.67 3.87 2.84 1.50

Drain from atmosphere, S3 331.07 243.21 252.21 240.24 234.32 233.10

Drain from atmosphere in CO2

 equivalents, Sg

4 331.07 238.61 242.21 228.04 221.92 222.10

1

 Base case projections.

2

 Change in stock of carbon = CIC + P + L.

3 S = CIC + P – (I – E) + L. (Net carbon drain from atmosphere.)

4

 Sg = CIC + P – (I – E) + L – 20(ECH4). (Net carbon drain from atmosphere in CO2 equivalents.)
86 Interim Update of the 2000 RPA Assessment
Interim Update of the 2000 RPA Assessment 87

It is important to understand the values that people assign to

the existence and use of renewable resources. Resources that

have little or diminishing value will tend to be ignored in terms

of investment in their maintenance and enhancement or will

be converted to other uses. This part of the RPA Assessment

Update presents available information for some indicators of

socioeconomic values held by society.

Timber

Production and consumption—Haynes et al. (2006)

project continued strong growth in total U.S. forest products

requirements (domestic consumption plus exports) to 2050.

Imports will continue to grow, but will supply a smaller portion

of the growth in total wood requirements, and domestic sources

a correspondingly larger share, over the next 45 years than

was the case during the previous five decades. This reduced

role for imports is based largely on the assumption that the

allowable annual cut in Canada will be lowered in the future,

especially after accelerated harvest in British Columbia in

response to the wide-scale infestation of timber by bark beetles.

Future harvests from domestic forests alone6 are expected to

grow each year by 0.11 billion cubic feet (Bcf), close to the

trend over the past 50 years of 0.12 Bcf/year (fig. 59). At the

same time, real product price growth will fall below long-term

historical rates for all products.

Over the 50 years from 1952 to 2002, U.S. consumption plus

exports of all forest products rose by some 9.5 billion cubic

feet per year. U.S. harvest increased by 6.0 billion cubic feet

and imports rose by 3.5 billion cubic feet over this same period

(fig. 59). Real prices of softwood lumber, hardwood lumber

and paper rose (compound rates of 0.8 percent, 0.4 percent and

0.3 percent, respectively), while prices of softwood plywood,

oriented strand board (OSB) (since 1976), and paperboard fell.

Projected U.S. consumption plus exports increases over the

2002–50 period by 8.0 billion cubic feet. Imports grow by 2.6

billion cubic feet, while harvest from forests and short-rotation

woody crop (SRWC) plantations rises by 5.4 billion cubic feet.7

Prices of softwood lumber, hardwood lumber, and OSB rise

slowly (0.2 percent, 0.3 percent and 0.1 percent, respectively),

prices of softwood plywood, paper, and paperboard remain

stable or fall.

Softwood harvest—U.S. softwood growing stock removals rise

slowly over the projection at about 0.6 percent per year, driven

entirely by expansion of pulpwood consumption (for OSB and

wood pulp). Sawtimber cut for lumber, plywood, and other

solid wood products declines slightly for the first decade of

the projection (to 2015) then recovers to near current levels by

2050 (fig. 60). The decline to 2015 reflects a modest reduction

in U.S. softwood lumber production and a steady fall in

plywood output. Housing starts are projected to move back to

levels of the late 1990s and the recent rapid growth in housing

unit size will come to an end. This slowing in end-use activity

is reflected in reduced softwood lumber consumption. At the

same time, softwood lumber imports, both from Canada and

off-shore sources, continue to out-compete domestic products.

Figure 59.—Total U.S. roundwood consumption, harvest, 

and trade.

6 Excluding agricultural short-rotation woody crops.

7 Domestic forest harvest rises by 5.3 Bcf and short-rotation woody crops by 0.1 Bcf.

Maintenance and Enhancement of Long-Term Multiple Socioeconomic Benefits 

To Meet the Needs of Societies
88 Interim Update of the 2000 RPA Assessment

The effects of a recently negotiated agreement with Canada

regarding softwood lumber imports remain to be tested.8 Thus,

in the period to 2015, imports grow while U.S. output slowly

declines. After 2015, driven by expansion in residential upkeep

and alteration (and by a resurgence in new housing after 2030),

growth in softwood lumber consumption and overall sawtimber

harvest resumes. This growth in harvest is also based on the

assumption that annual allowable harvest levels will be reduced

in Canada. Softwood plywood consumption and output fall

steadily through 2030, as substitution by OSB in all major

markets continues.

In contrast, U.S. paper and paperboard output and OSB

production continue to expand throughout the projection,

driving up pulpwood consumption and total softwood

nonsawtimber harvest (fig. 60). Between 2006 and 2050, total

U.S. pulpwood consumption (at OSB and wood pulp mills)

is projected to grow at an average annual rate of just over

0.8 percent, roundwood pulpwood consumption is projected

to grow annually at about 1.1 percent, and wood residue

pulpwood consumption is expected to decline by 0.7 percent

per year. During this period, OSB production will expand at

1.3 percent per year and U.S. pulp production at 0.7 percent

per year. OSB consumption will rise steadily, both because it

continues to capture market share from softwood plywood and

because it accounts for essentially all of the future growth in

structural panel consumption.

U.S. paper and paperboard production and consumption both

experienced a significant downturn after 1999, associated with

economic globalization and a decline in overall U.S. industrial

production. Downsizing and import competition have resulted

in structural changes in U.S. manufacturing, and also in paper

and paperboard production, with substantial labor productivity

gains achieved by U.S. producers through consolidation and

automation.

In 2004, U.S. output of paper and paperboard increased by

more than 4 percent, as one element in a general recovery in

U.S. industrial production. Although U.S. paper and paperboard

production dipped again, by 1 percent in 2005, it is projected

to increase in the period to 2050, in line with expected growth

in consumption, population, and overall economic activity.

Per capita consumption of paper and paperboard is projected

to remain essentially flat at about 700 pounds in the decades

ahead. The current growth outlook for U.S. production of

paper, paperboard, and wood pulp contrasts sharply with the

trends of the late 20th century (fig. 61). Whereas U.S. paper and

paperboard output increased at an average annual rate of 2.3

percent from 1970 to 1999, the base projections from 2001 to

2050 yield an average annual rate of only 0.8 percent, with very

modest expansion in production capacity.

U.S. wood pulp production is projected to increase at an

average annual rate of 0.7 percent (2001 to 2050), less than half

the historical growth rate from 1970 to 1999 (fig. 61). Wood

pulp output growth stems in part from projected growth in

paper and paperboard output and from limited projected growth

in domestic recycled fiber use. Paper recovery for recycling

in the United States is projected to climb above the current

recovery rate of 50 percent, but growth in exports (mainly to

China) accounts for the largest share of projected expansion in

paper recovery.

Figure 60.— U.S. sawtimber and nonsawtimber harvest by 

species group.

8 According to the framework of the agreement, no tax or quota is in place when the Random Lengths Framing Lumber Composite Price is higher than $355

per thousand board feet. If the Composite Price is $355 or less, the various producing regions in Canada can either pay an export tax of 5–15 percent (the

lower the Composite Price, the higher the tax), or pay a lower tax and have a quota in place (Random Lengths 2006)
Interim Update of the 2000 RPA Assessment 89

As U.S. municipalities shift toward single-stream recycling

(commingled curbside collection) to reduce collection costs,

downstream recycling industries incur higher expenses for

sorting and separation. This approach favors shipment of

recovered paper to countries such as China, where labor for

hand sorting is cheap and paper-recycling capacity is rapidly

expanding. U.S. recovered paper exports doubled in the past

decade, with China the leading export destination, and are

projected to increase from 16 million tons in 2005 to more than

26 million tons by 2050.

Hardwood harvest—Total hardwood harvest on forest land is

projected to increase steadily over the projection. On average,

hardwood harvest (excluding SRWCs) is projected to increase

at 0.4 percent per year from 2005 to 2050. As in the case of

softwoods, the increase is due to expansion of the pulpwood

component of nonsawtimber harvest (fig. 60).

The net effect of the projected trends in fiber use and

production is a relatively stable distribution of hardwood and

softwood in projected U.S. pulpwood consumption. With

increased wood pulp output, pulpwood consumption at pulp

mills is projected to increase. The projected trend in hardwood

pulpwood consumption is relatively flat as the hardwood share

of total pulpwood consumption at wood pulp mills is projected

to gradually decline. Historically, increased recycling had a

more pronounced impact on growth in softwood pulpwood

receipts at wood pulp mills (peaking in the late 1980s, see

fig. 62), because recycled fiber use expanded more rapidly in

paper and paperboard products that traditionally used large

proportions of softwood fiber (newsprint and containerboard).

Both softwood and hardwood pulpwood consumption were

altered by economic globalization and the downturn in paper

and paperboard output of the past decade. In the future, the

projected leveling in printing and writing paper output affects

hardwood receipts more than softwoods.

Projected growth in U.S. softwood pulpwood consumption

(at about 0.9 percent per year between 2006 and 2050) is

well below the 1960–2003 trend rate of 1.4 percent (fig. 62).

Softwood, however, accounts for the largest share of projected

gains in pulpwood consumption. The projected growth in U.S.

softwood pulpwood consumption is supplied primarily by

southern pine plantations.

In contrast, hardwood harvests for sawtimber products are

relatively stable over the projection (fig. 60). This pattern is

dictated by end-use consumption trends in hardwood lumber,

where declining use for pallets and furniture offset growth in

use for millwork and miscellaneous products.

Prices—The 2005 RPA Assessment Update projects a very

moderate future for growth in real forest products prices. Prices

of some solid wood products are expected to rise (lumber and

OSB), but at rates that are small in absolute terms (all 0.3

percent or less) and well below those of the past five decades.

Figure 61.— U.S. paper, paperboard, and pulp production. Figure 62.— U.S. receipts of pulpwood at pulpmills by 

species group.

Source: AF&PA (historical data): TNA (projections, May 2006). Source: FRA & Forest Service (historical data): TNA (projections, March

2006).

Recycling had big impact on softwood in the 1980s 

and early 1990s (via newsprint & containerboard)

U.S. paper & paperboard production

U.S. wood pulp production
90 Interim Update of the 2000 RPA Assessment

Prices for the large aggregates of paper and paperboard are

expected to decline in real terms (fig. 63). Limited product

price growth derives from continued improvements in input use

efficiency in domestic production, competition from substitute

products, and continued pressure from lower cost imports

across the whole array of product classes.

Slow product price growth is reflected in many categories of

timber prices (fig. 64). Sawtimber stumpage prices in the South

and interior West decline slowly after 2010, while those in

western Washington and western Oregon and the North rise at

about 0.2 percent and 0.8 percent per year. Southern hardwood

pulpwood prices rise in the projection as hardwood inventories

contract. Southern softwood pulpwood prices oscillate in

response to the changing fiber mix, ending the projection near

recent levels.

Employment—Total employment in the forest sector is

increasing and accounts for roughly 2 percent of all U.S.

jobs (fig. 65). This percentage includes employment in wood

and paper products firms, forest-based recreation, forest

management, and forestry education (Skog et al. 2004). In

2000, jobs in logging, lumber and wood products, and paper

and allied products were 1.1 percent of all U.S. jobs and 8.1

percent of manufacturing jobs (849,000 and 660,000 jobs,

respectively). These percentages indicate a decline in share of

jobs since 1950, from 2.5 percent of all jobs and 8.6 percent of

manufacturing jobs. However, employment in logging, lumber,

and wood products in 2000 was higher than in 1950 (849,000

and 824,000 jobs, respectively), as was the case for paper and

allied products (660,000 and 485,000 jobs, respectively). Jobs

in wood furniture industries were 182,000 in 1997.

Although the current number of direct jobs from forest-based

recreation is uncertain, a rough estimate for the United States is

1.1 million or 0.8 percent of all U.S. jobs (table 9). An increase

may be inferred by the increase in participation in U.S. forest

recreation.

Jobs in forest management include those in the Forest Service,

29,400 in 2001, down from 37,236 in 1980; jobs on tribal lands

in the DOI Bureau of Indian Affairs and tribal governments,

Figure 63.—Real prices for forest products.

Figure 64.—Real prices of softwood sawtimber stumpage by 

region and real pulpwood stumpage prices in the South (all 

in 1982 dollars).

Figure 65.—Employment in wood and paper products mills 

as a percentage of total employment and manufacturing 

employment from 1930 to 2000.

3.0

2.5

2.0

1.5

1.0

0.5

0

1950

Price index 1982=1.0

Softwood lumber Hardwood lumber Softwood plywood Oriented 

 strand board

19551960196519701975198019851990199520002005201020152020202520302035204020452050

450

400

350

300

250

200

150

100

50

0

Dollars per thousand board feet

1950

1955

1960196519701975198019851990199520002005201020152020202520302035204020452050

Pacific Northwest West North South Interior West

10

8

6

4

2

0

Percent

Manufacturing

Total

193019341938194219461950195419581962196619701974197819821986199019941998
Interim Update of the 2000 RPA Assessment 91

about 900 in the early 1990s; in State forestry agencies, 12,405

permanent and 5,648 seasonal in 1996; in the BLM, 9,728 in

1997; and an undetermined number in county and municipal

governments, private land management organizations, private

consultants, and private forest-resource-related organizations.

Firefighting and support jobs during fire season have recently

numbered from 12,000 to 15,000 a year nationwide. Management of forests in parks includes forests in the National Park

Service (18,361 total in 1997), and thousands of jobs in forests

managed by State, county, tribal, and municipal governments.

Jobs in forest management education and research in 2001

include colleges and universities, 1,361; Forest Service

research, 701 (included in the Forest Service total), and

industry research, 124; and an undetermined number in

providing forest resource education in high schools, and in

education efforts of private associations and organizations.

Total forest-related jobs are estimated to be close to 3 million

or a little more than 2 percent of all U.S. employment.

This estimate does not include indirect jobs generated by

expenditures of government agencies, businesses, or others.

Direct jobs in forest-based recreation and tourism employment

is estimated to be highest in the North, followed by the South,

Rocky Mountains, and Pacific Coast.

In 1997, forest products industry employment was highest in

the North, at about 600,000, followed by the South (550,000),

Pacific Coast (200,000), and Rocky Mountains (70,000). 

In 1996, employment in State forestry agencies was highest in

the South (6,064 permanent and 1,508 temporary), followed

by the North (3,399 permanent and 1,934 temporary), Pacific

Coast (2,017 permanent and 1,714 temporary), and Rocky

Mountains, (924 permanent and 492 temporary).

Indirect jobs (from indirect and induced effects) supported by

expenditures of wood products firms, furniture firms, paper

products firms and forest-recreation-related business, are

estimated to be 2.2 million, 1.2 million, 2.7 million, and 0.9

million, respectively (table 9).

Alternative futures for timber and related markets—

Haynes et al. (2006) projected various measures of timber

inventory and timber markets in a “base case” (discussed

previously). They then varied background assumptions

one at a time and recast the projection to learn more about

the sensitivity of outcomes to external conditions. Seven

alternative projections are (1) increased timber harvest in

British Columbia caused by an effort to salvage mortality due

to an outbreak of mountain pine beetle, (2) a stronger U.S.

dollar, (3) accelerated reduction in other private timberland

area, (4) possible effects of climate change on timber growth

rates, (5) increased public timber harvest in the West consistent

with one possible restoration thinning program, (6) planting of

additional plantations to sequester carbon, and (7) reduced rate

of pine plantation establishment on other private lands in the

south-central region. Rationales for selection of the alternatives

are discussed in Haynes et al. (2006).

Table 9.—Direct employment and indirect employment from indirect and induced effects of four forest-based sectors in 1999.

Industry

Jobs per million dollars

industry output Industry 

output 

(million $)

Number of jobs1

Direct 

effect

Indirect 

effect

Induced 

effect

Total 

effect

Direct 

effect 

Indirect 

effect 

Induced 

effect Total 

Wood products 7.7 9.0 8.9 25.6 122,715 941,302 1,106,253 1,089,924 3,137,471

Wood furniture 8.2 8.3 9.2 25.8 70,963 584,973 588,602 655,881 1,829,448

Pulp and paper 4.0 7.8 8.2 20.1 167,293 669,733 1,310,387 1,375,560 3,355,671

All wood products 6.1 8.3 8.6 23.1 360,971 2,196,008 3,005,238 3,121,361 8,322,607

Recreation/tourism 16.1 5.8 8.1 30.3 67,726 1,091,576 389,568 549,569 2,030,713

1

 Number of jobs includes full-time, part-time, and self-employed jobs. 

Source: Minnesota Implan Group, Inc. 1997, using 1999 data. 
92 Interim Update of the 2000 RPA Assessment

Each of the alternatives was modeled as a shift in timber

supply. The availability of many types of substitute products

and many sources of supply for any given forest product act

to reduce the price impacts of supply shifts in forest product

markets. For example, increased public harvest in the West

under a restoration thinning program raises western softwood

lumber output, but reduces production in the South and lowers

the volume of softwood lumber imports. Of the western

softwood lumber increment, 75 percent is offset by substitution

across regional suppliers.

Substitution also regulates adjustment to supply shifts

within a region. For example, fewer acres of planted pine

on nonindustrial private forest lands in the south-central

region cause stumpage prices to increase. Forest industry

and institutional owners in the south-central region respond

to the higher prices by increasing output and moderating the

stumpage price increase.

Box 20

Timber processing capacity for various products in the 

West—A special concern related to timber supply is the

availability of processing capacity. This issue was previously

highlighted as a potential issue related to globalization

and the continued loss of the timber industry. The lack of

processing capacity is also an issue in the West in regards to

markets for small-diameter timber. The need to clear more

small-diameter timber in the West to restore forest health

has been highlighted in the Healthy Forest Restoration Act

of 2003 (HR 1904). Keegan et al. (2004) estimated timber

processing capacity and capabilities in the Western United

States for trees less than 7 inches diameter breast height

(d.b.h.), trees 7 to 9.9 inches d.b.h., and trees equal to or

greater than 10 inches d.b.h. Timber processing capacity

is defined as the volume of timber that could be used by

existing timber processors if demands for products were

firm and sufficient raw materials were available. Timber

processing capability is the volume of trees that could be

processed efficiently at prices comparable to 1999–2001. The

study area included the Pacific Coast and Rocky Mountains

regions less the Great Plains States.

Calculations of timber processing capacity and timber use

included facilities that primarily use timber to manufacture

products. Sawmills, veneer/plywood plants, and producers

of utility poles and pilings, posts, small poles, stakes,

roundwood furniture, house logs and log homes, vigas

and lattillas, cedar shakes, shingles, and split rail fencing

were included. Timber use was estimated separately for

manufacturers that primarily use industrial fuelwood or

roundwood pulpwood, as well as log exporters.

In the study regions between 1986 and 2003, harvest on

national forests declined from 9.9 billion board feet to 1.1

billion board feet. Associated with the decline in harvest

was a 37-percent decline in capacity to process timber and

a 32-percent decline in timber use. In the late 1980s, mills

received 40 percent of their timber from national forests.

By 2003, less than 10 percent of timber harvested in the

study area came from national forests. Most of the capacity

decline (from 5 to 3.18 billion cubic feet) occurred between

1986 and 1996. Capacity remained essentially unchanged

from 1996 to 2003; however, timber use increased 6 percent

between 1996 and 2003. Proportionately, capacity declines

were greatest in the four corners area which was also the area

with the greatest dependence/use of national forest timber.

Most of the timber processing capability (94.7 percent)

and use (97.3 percent) is in the five States of California,

Idaho, Montana, Oregon, and Washington (table 10). Use

amounted to 77.6 percent of capability. Alaska has the lowest

use versus capability (12.8 percent). Sawmilling capability

to process timber less than 7 inches d.b.h. amounted to

2.4 percent of the total capability. About 59 percent of the

capability to process timber less than 7 inches d.b.h. was

located in Oregon and Washington. About 25 percent of the

capability was used.
Interim Update of the 2000 RPA Assessment 93

Box 20 (continued)

The capability to process timber 7 to 9.9 inches d.b.h.

amounted to 17.7 percent of the total capability and 7.9

percent of use. Use as a percent of capability for timber 7 to

9.9 inches d.b.h. was 34.7 percent. Much of the capability

(87 percent) to use timber in this size class was in California,

Montana, Oregon, and Washington. Actual use of timber

in this size class was mainly (73 percent) in Oregon and

Washington.

Timber was also used for pulpwood and industrial fuelwood, or was exported as logs. Since 1986, use of timber for

pulpwood and industrial fuelwood in the study area ranged

from about 100 million cubic feet to 300 million cubic feet

annually. In recent years, the total annual use of roundwood

for pulp and industrial fuel has been near the low end of the

range, with more than 50 percent of the volume from live

trees greater than or equal to 10 inches d.b.h. Log exports

during the 1986 to 2003 period ranged from more than 850

million cubic feet annually in the late 1980s to less than 200

million cubic feet in recent years. Virtually all exported timber was from trees greater than or equal to 10 inches d.b.h.

Table 10.—Timber processing capability (million cubic feet) and percent used by State and tree diameter class.

Tree d.b.h. (inches)

State Less than 7.0 7.0 to 9.9 All sizes

Capability % used Capability % used Capability % used

AK < 0.05 NA 2.0 < 0.02 47.0 12.8

AZ 0.2 100.0 1.1 100.0 18.7 69.0

CA 9.4 0.5 60.0 22.2 558.7 65.0

CO 3.0 43.3 16.2 22.2 35.0 48.3

ID 3.9 76.9 34.5 33.0 264.9 83.8

MT 9.1 29.7 77.3 26.1 226.6 76.7

NM 0.4 25.0 1.4 12.3 7.3 59.3

OR 27.0 33.3 225.0 51.1 1,104.0 86.6

UT 1.2 41.7 48.0 20.8 12.7 48.8

WA 17.0 < 0.01 126.0 21.4 840.0 79.9

WY 3.7 29.7 12.8 7.8 41.9 41.1

Total 74.9 24.6 561.1 34.7 3,161.8 77.6

Water

About 70 percent of the Earth’s surface is covered with water.

Some 97.5 percent of the water on the planet is in oceans and is

too salty to drink or grow crops. Most of the 2.5 percent that is

not salt water is tied up in ice caps. Less than .00008 percent is

annually renewable and available in rivers and lakes for human

and wildlife use (Sedell et al. 2000).

Supply—The supply of usable water is largely fixed. Most

opportunities to develop water sources have been implemented.

Some existing sources of water, such as dams, are losing their

utility because of siltation. The demand for water continues to

increase. Because of fixed supply and increasing demand, the

value of the water resource is increasing.

About 53 percent of the Nation’s water supply originates on

forest land, 26 percent on agricultural land, and 8 percent on
94 Interim Update of the 2000 RPA Assessment

Figure 66.—Water withdrawals for off-stream use by type of 

use.

rangeland (Brown et al. 2005). Forested areas contributed 49

percent of the water supply in the conterminous States west of

the Mississippi River and 56 percent in the East. Most of the

rangeland is west of the Mississippi River, and thus rangeland

is more important as a source of water in the West than in the

East. Agriculture is relatively more important as a source of

water east of the Mississippi River than for the West.

About 24 percent of the water supply in the contiguous 48

States originates on Federal land. Eighteen percent of the

Nation’s water supply originates on lands of the NFS alone

even though these lands occupy only about 11 percent of the

surface area. Land in State and private ownership supply the

remaining 76 percent. Because Federal lands are concentrated

in the western part of the country, the contributions of Federal

lands to water supply are relatively more important west of the

Mississippi River than for lands east of the Mississippi. West of

the Mississippi River, 42 percent of the Nation’s water supply

originates on Federal land, with 32 percent on Forest Service

land alone compared with 9 percent and 7 percent, respectively,

east of the Mississippi.

Withdrawals—After continual increases in the Nation’s total

water withdrawals for offstream use for the period 1950–80,

withdrawals declined from 1980 to 1985 and stabilized at about

400 billion gallons per day through 2000 (fig. 66) (Hutson et al.

2004).

Estimated withdrawals for public supply increased continuously since 1950, along with population served by public suppliers. The percentage of population served by public suppliers

increased from 62 percent in 1950 to 85 percent in 2000.

Estimated withdrawals for self-supplied domestic use increased

by 71 percent between 1950 and 2000. The self-supplied

domestic population was 57.5 million people in 1950, or 38

percent of the total population. For 2000, 43.5 million people,

or 15 percent of the total population, were self-supplied.

Data for withdrawals for livestock and aquaculture use includes

fish farms from 1985 to 2000. Withdrawals increased from

1985 through 1995. Data for a total in 2000 is not available.

Withdrawals for irrigation increased through 1980 and then stabilized. Depending on the geographic area of the United States,

the decrease since 1980 can be attributed to climate, crop type,

advances in irrigation efficiency, and higher energy costs.

Thermoelectric power has been the category with the largest

water withdrawals since 1965. Since 1980, withdrawals have

been relatively stable. Withdrawals were affected primarily by

Federal legislation that required stricter water quality standards

for return flow and by limited water supplies in some areas of

the United States. The average gallons of water to produce 1

kilowatt-hour decreased from 63 in 1950 to 21 in 2000.

The decline in other industrial use reflects stricter water quality

standards for water discharges which encouraged conservation,

greater efficiency, and lower water-using technologies. The

decline in withdrawals is also attributable in part to a decline in

manufacturing and reclassification of fish farms in 1985. Data

for a total is not available for 2000.

Possible future trends—Brown (1999) projected total U.S.

withdrawals to rise by 7 percent between 1995 and 2040

despite a projected 41-percent increase in population. This

situation reflects the improving efficiencies projected for the

municipal and industrial and thermoelectric sectors and the

projected reductions in total irrigation withdrawals.
Interim Update of the 2000 RPA Assessment 95

Minerals9

Production and consumption—In 2004, the U.S. economy

used more than $200 billion of domestically produced nonfuel

minerals plus more than $100 billion of domestically produced

crude oil, natural gas, and coal. In addition, the U.S. economy

also depended upon domestic reclaimed metals, mineral

materials, and imports of energy and mineral raw materials.

A wide range exists in the extent of domestic production of

minerals. The United States mining industry accounts for

about one-quarter of the world’s production of molybdenum

and phosphate and about one-fifth of the natural gas and coal.

It produces no chromium and very little of the metals in the

platinum group. The United States is a net exporter of gold and

molybdenum. About 40 percent of the unprocessed minerals

and 12 percent of fertilizer and chemical minerals currently

used in the United States are imported.

The Nation has extensive coal reserves and is a net exporter of

coal. Coal production west of the Mississippi River exceeded

production east of the Mississippi River for the first time in the

late 1990s. More than 90 percent of the total U.S. energy needs

are met by petroleum, natural gas, or coal. In contrast to coal,

the United States relies on imports for 57 percent of petroleum

consumption and 15 percent of natural gas consumption.

Investment—The contribution of energy and minerals

industries to the U.S. gross domestic product declined from

2.66 percent in 1977 to 1.37 percent in 2001. Some of the

decrease reflects lower prices and some decreased production,

as well as increased growth in other sectors of the economy.

Despite this decline in relative importance, the industry remains

essential to the national economy and is especially important

for the economies of some States. For example, in 2001, the

nonrenewable resource sectors accounted for 22.2 percent of

the gross State product in Wyoming, 16.7 percent in Alaska,

14.9 percent in Louisiana, and 9.1 percent in West Virginia.

Employment—Employment in all sectors of the industry

peaked in the late 1970s or early 1980s. The decline reflects in

part declines in production levels (oil and gas), increases in productivity (coal), and changes in extraction technology (metals).

In 2001, the mineral industry employed about 558,000 people.

Real hourly wages ($1996) for all production workers increased

slowly from $11.77 in 1977 to $13.34 in 2001. Compensation

in the metals mining industry increased from $16.33 in 1977 to

$19.05 in 2001 and for nonmetals, from $13.03 to $15.53. For

all production workers and the metal and nonmetal sectors, most

of the increase in wages occurred in the 1990s. Wages in the

coal industry were $18.48 in 1977, peaked at $20.74 in 1984–

85, and declined to a low of $17.80 in 2001. For oil and gas,

wages were $14.29 in 1977, a peak of $15.40 in 1986, reaching

a low of $14.51 in 1990, and increasing to $18.65 in 2001.

Outdoor Recreation

Availability of facilities for recreation and tourism found on

forests and rangelands, and their use by people, are indicators

of whether people enjoy the out-of-doors for these purposes,

and that they are therefore likely to support management of

the land on a sustainable basis. Research examining forest

visitor perceptions about livestock grazing has shown that most

forest visitors are conditionally supportive of management if

the management objective provides for sustaining ecosystem

health, protecting streams and lakes, and reducing conflicts

among various user groups.

Available data are primarily for participation in recreational

activities regardless of the type of land or its ownership. Thus,

no direct measurements of recreation and tourism occur on

forest land or rangeland.

For availability of forest land, we know that almost all publicly

owned forest land (42.5 percent of the total forest land area) is

available for recreational purposes. Lack of access or regulation

9 The analysis in this section on minerals is from personal communication from Deborah Shields, Rocky Mountain Research Station, Fort Collins, CO.
96 Interim Update of the 2000 RPA Assessment

of permitted activities such as in Wilderness areas may limit

recreational use of these lands. Access to privately owned

forest lands for recreational purposes can vary by ownership.

From a survey of owners of private forest land, we do know

that recreational use of their land is a primary objective for

many owners (Butler and Leatherberry 2004). The proportion

of privately owned forest land open to the public and free of

charge declined steadily from 29 percent in 1979 to 23 percent

in 1989, 15 percent in 1996, and 11 percent in 2001. Access to

the remaining privately owned forest land is at the discretion

of the owner and can vary from no access to free access.

Recreational activities most likely to occur on private lands by

the general public are hunting and other activities that require

large open areas.

Participation—Congress created and funded the Outdoor

Recreation Resources Review Commission (ORRRC) to study

demand and supply of outdoor opportunities for Americans

(Outdoor Recreation Resources Review Commission 1962).

From that time, we have tracked outdoor recreation trends

in this country using the National Recreation Survey Series

that was begun by ORRRC. Here, we examine long- and

short-term trends in Americans’ participation in outdoor

recreation activities. All data are from various applications of

the National Recreation Survey, the most recent of which has

been published as a book entitled Outdoor Recreation for 21st

Century America (Cordell et al. 2004).

Trends since 1960—Since the first national recreation survey

was conducted in 1960, the number of people legally living in

this country has expanded to 300 million (U.S. Bureau of the

Census 2006). That first survey was conducted in 1960 and

reported in 1962. It is this survey and subsequent ones that we

reference in examining briefly long-term participation trends.

Subsequent national recreation surveys were repeated in 1965,

1972, 1977, 1982, 1995, 2000, and 2001.

Population growth has been highly correlated with changes in

recreation participation seen in this country over the past 44

years. But population is not the only factor underlying growing outdoor recreation participation. Continuing growth in

economic welfare, improved personal equipment technology,

easier transportation, and better information are also contributors. Within the overall growth we have seen in outdoor recreation participation, some activities have grown faster, and

some slower. This shifting in the hierarchy of popularity among

activities clearly indicates that people’s tastes, abilities, and the

supply of opportunities has been changing.

Growing fastest between 1960 and 2000–01 are bicycling,

camping, canoeing/kayaking, and swimming. Advancement

of the technology of bicycles has transformed what was once

a close-to-home, slow-paced activity into one involving many

different types of biking with a wide variety of equipment

and outdoor venues. The appearance of mountain bikes in the

late 1970s and especially their more affordable availability

beginning in the early 1980s was an especially significant

development.

Technology and changing lifestyles also have impacted outdoor

activity. Camping is a good example. Campgrounds now serve

less the tent camper of the 1960s and more the contemporary

travelers with large, high-technology motor homes and towed

residences. Hookups for electricity, water, sewage, cable TV,

phone, and high-speed cable for lap tops are no longer considered just nice-to-have amenities. Campers also demand hot

showers, computer games, and other entertainment for children.

Participation in canoeing and kayaking grew from 2.6 million

in 1960 to approximately 15 million in 1982–83, and then to

27.7 million in 2000–01. Today’s kayaks include hole-riding

boats, surfing boats, boofing boats, squirting boats, beginner

boats, intermediate boats, advanced boats, and boats for all

sizes of paddlers. Swimming, unlike other fast-growing activities, is not especially driven by technology. Its slower paced

rise has been driven by persistent popularity and population

growth. From 1995 to 2001, the proportion of people who said

they went swimming outdoors in the past year held constant

at about 55 percent. Due to population growth, however, this

steady percentage participating has meant an increase of about

9 million swimmers to approximately 125 million.

Trends in the past 20+ years—Viewing or photographing

birds was the activity growing fastest in this country from the

early 1980s up to the early 2000s. There were more than 50

million additional birding participants in 2001 than in the early
Interim Update of the 2000 RPA Assessment 97

1980s. Since the 1982–83 national survey, the growth rate in

birding participation has exceeded 231 percent. Following

birding has been day hiking and backpacking at 194 and 182

percent growth, respectively. Snowmobiling grew 125 percent

in those almost 20 years between surveys. A second motorized

activity within the list of fastest growing activities was driving

motorized vehicles off road, including all-terrain and other

four-wheel-drive vehicles.

Other activities growing fast, at between 50 and 100 percent

since 1982, were attending outdoor concerts, plays and other

events; walking for pleasure; camping in developed sites;

canoeing or kayaking; running or jogging; downhill skiing and

swimming in natural waters (i.e., streams, lakes, and oceans).

Five of these seven activities are physically active. Growing at

between 25 and 50 percent were the activities of ice skating,

visiting nature centers/museums/etc., picnicking, horseback

riding, sightseeing, and driving for pleasure. Most of these

activities are relatively passive and are done within the confines

of development or vehicles.

Because, generally, men participate in most activities at

higher rates than women, the trends men set tend to have

more influence on most population-wide activity trends

(table 11). Trends in participation in walking for pleasure,

running/jogging, driving motor vehicles off road, primitive

camping, backpacking, fishing and snowmobiling have been

greatly influenced by growth in participation by men. For

most activities, however, participation by women has grown

substantially and is becoming a larger overall share of the

participant numbers. Regarding age-related trends, participation

by the oldest age group, persons age 60 or older, was strongly

up for a number of activities—putting older Americans

among the outdoor trend setters. Regarding race (not shown

in table 11), whites’ trends in participation was a major driver

of population-wide trends for most activities, especially for

Table 11.—Estimated percentages of persons age 12 years or older who participated one or more times in the 12 months from 

2000–01 and 1982–831 by activity, gender, and age.

Activity Population Male Female Age 12–24 Age 25–39 Age 40–59 Age 60+

Land activities

Walking for pleasure 83.1

(53)

79.8

(45)

86.0

(61)

84.7

(57)

83.8

(58)

84.6

(53)

78.8

(42)

Visiting nature centers, etc. 57.1

(50)

57.7

(50)

56.6

(51)

57.1

(65)

66.9

(62)

60.1

(41)

39.8

(26)

Picnicking 53.9

(48)

51.2

(45)

56.4

(51)

46.1

(52)

60.8

(59)

59.6

(46)

46.0

(29)

Sightseeing 51.4

(46)

49.7

(45)

53.0

(46)

45.4

(46)

53.9

(54)

56.7

(47)

46.7

(31)

Driving for pleasure 51.0

(48)

51.1

(47)

51.0

(49)

47.8

(48)

53.1

(59)

55.7

(46)

43.7

(35)

Attending outdoor sports events 50.7

(40)

56.0

(44)

46.1

(36)

62.7

(55)

53.6

(44)

49.1

(36)

35.9

(16)

Attending outdoor concerts, etc. 40.7

(25)

40.6

(25)

40.7

(26)

53.7

(34)

39.4

(29)

38.8

(22)

30.6

(12)

Bicycling 40.7

(32)

45.3

(33)

36.5

(32)

56.9

(55)

46.9

(37)

37.3

(22)

19.1

(7)

Running or jogging 37.3

(26)

44.7

(30)

30.6

(23)

73.9

(51)

38.1

(31)

23.4

(13)

12.3

(2)

Day hiking 33.3

(14)

37.0

(15)

29.9

(13)

33.8

(19)

40.3

(17)

35.5

(12)

19.2

(5)

Viewing/photographing birds 31.8

(12)

29.3

(11)

34.1

(12)

24.1

(10)

30.1

(12)

38.4

(12)

35.6

(13)

Camping (developed) 26.8

(17)

28.7

(18)

25.1

(16)

32.7

(24)

31.1

(22)

27.1

(15)

14.3

(5)
98 Interim Update of the 2000 RPA Assessment

Table 11.—Estimated percentages of persons age 12 years or older who participated one or more times in the 12 months from 

2000–01 and 1982–831 by activity, gender, and age (continued).

1 1982–83 information in parentheses.

NA = Not available.

Sources: 1982–1983 National Recreation Survey; National Survey on Recreation and the Environment, 2000-2001.

Activity Population Male Female Age 12–24 Age 25–39 Age 40–59 Age 60+

Playing outdoor team sports 24.5

(24)

33.0

(30)

17.0

(18)

49.8

(50)

27.0

(26)

15.4

(11)

4.7

(2)

Driving off road 18.3

(11)

23.2

(14)

13.8

(8)

28.9

(20)

20.9

(11)

15.1

(6)

6.3

(2)

Golfing 17.2

(13)

25.3

(20)

9.8

(7)

22.3

(16)

18.7

(13)

16.3

(13)

10.2

(7)

Camping (primitive) 16.6

(10)

22.0

(11)

11.7

(8)

24.2

(17)

18.6

(11)

15.1

(6)

6.0

(2)

Playing tennis outdoors 12.7

(17)

13.9

(18)

11.7

(16)

28.1

(32)

11.7

(20)

7.4

(10)

2.9

(1)

Hunting 11.6

(12)

20.3

(22)

3.7

(3)

15.3

(15)

12.3

(13)

11.3

(13)

6.8

(5)

Backpacking 11.1

(5)

14.6

(6)

7.9

(3)

16.4

(9)

13.8

(5)

9.7

(2)

2.5

NA

Horseback riding 10.2

(9)

10.6

(8)

9.8

(10)

16.3

(18)

11.6

(10)

9.1

(5)

2.7

(1)

Water activities

Swimming in natural waters 42.8

(32)

45.5

(34)

40.5

(30)

56.4

(49)

50.1

(40)

41.7

(21)

17.8

(7)

Swimming in outdoor pool 42.6

(43)

41.0

(43)

44.0

(42)

63.5

(67)

48.5

(49)

37.0

(33)

18.0

(11)

Fishing 34.7

(34)

45.1

(47)

25.4

(23)

42.4

(43)

37.6

(40)

34.9

(31)

22.1

(17)

Motorboating 24.8

(19)

29.4

(22)

20.7

(16)

29.6

(25)

27.8

(23)

24.9

(17)

14.5

(7)

Canoeing or kayaking 12.1

(8)

14.6

(10)

9.9

(7)

19.2

(14)

12.9

(9)

11.2

(6)

3.8

(1)

Waterskiing 8.8

(9)

11.1

(11)

6.8

(7)

17.7

(17)

10.1

(12)

5.6

(4)

0.8

NA

Sailing 5.3

(6)

5.5

(7)

5.2

(5)

7.6

(9)

5.3

(7)

5.2

(5)

2.8

(2)

Snow and ice activities

Sledding 15.7

(10)

16.6

(12)

14.8

(9)

30.5

(22)

19.7

(11)

10.9

(5)

2.3

NA

Skiing downhill 9.1

(6)

11.1

(8)

7.3

(5)

16.1

(12)

10.6

(8)

7.0

(3)

1.3

(1)

Ice skating 7.7

(6)

7.6

(6)

7.7

(6)

18.2

(15)

8.2

(6)

4.4

(3)

0.6

NA

Snowmobiling 5.9

(3)

7.6

(4)

4.5

(2)

10.5

(6)

6.8

(3)

4.3

(2)

1.3

NA

Skiing cross country 3.9

(3)

4.3

(4)

3.6

(3)

5.3

(5)

3.9

(4)

4.7

(3)

1.4

NA
Interim Update of the 2000 RPA Assessment 99

outdoor sporting events, day hiking, viewing/photographing

birds, golfing, primitive camping, swimming, motor boating,

canoeing/kayaking, and snowmobiling.

Trends since 1995—The most popular activities in 2000–01

(those having the most participants), included walking for

pleasure, outdoor family gatherings, and visiting a beach.

These are the same activities that were at the top in 1994–95.

Examining percentage growth by activity, however, shows

that the hierarchy of popularity among activities is changing

over time. Of the 62 activities examined through the National

Survey on Recreation and the Environment, many at the

top of the list, when ranked by percentage growth from

1994–95 to 2000–01, are physically demanding (table 12).

Highly physical and challenging sports, such as kayaking,

snowboarding, backpacking, and mountain climbing, typically

require specialized equipment and skills not possessed by

everyone. Together with larger numbers of people participating

in outdoor activities in 2001, a changing mix of activities

means very noticeable differences between what one would

have witnessed at a typical outdoor area in earlier times, and

now. Many of the activities at or near the top of this list in

terms of percentage growth do not represent large numbers of

added people (for example, participants in kayaking) while

others further down the list with lower percentage growth have

increased substantially in total numbers. Numbers reporting

viewing and photographing wildlife, for example, have risen by

more than 34 million and viewing or photographing fish have

risen by more than 26 million.

Table 12.—Participation percentages and number of participants in the United States by the 20 fastest growing activities from 

1994–95 to 2000–01.

Sources: NSRE 1994–95 data (1995 number of participants based on estimate of 195.8 million, civilian, noninstitutionalized population 16 years and older); NSRE 

2000–2001, Versions 1-9 (2000–01 number based on estimate of 213.1 million, civilian, noninstitutionalized people 16 years and older).

Activity

Percent 

participating 

1994–95

Millions of 

participants 

1994–95

Percent 

participating 

2000–01

Millions of 

participants 

2000–01

Percent 

increase

 1994–2001

Kayaking 1.3 2.6 3.5 7.4 185.7

Snowboarding 2.3 4.4 4.9 10.4 134.8

Jet skiing 4.7 9.3 9.5 20.3 119.3

Viewing or photographing fish 13.7 26.8 24.8 52.8 96.8

Playing soccer outdoors 4.7 9.3 8.1 17.3 87.2

Snowmobiling 3.6 7.0 5.6 11.8 70.2

Ice fishing 2.0 3.9 2.9 6.2 59.5

Sledding 10.2 20.0 14.7 31.2 56.2

Viewing wildlife 31.2 61.1 44.7 95.2 55.8

Backpacking 7.6 14.8 10.7 22.8 53.8

Day hiking 23.8 46.7 33.3 70.9 51.8

Canoeing 7.0 13.8 9.7 20.7 50.7

Bicycling 28.7 56.1 39.5 84.2 50.0

Horseback riding 7.1 13.9 9.7 20.6 48.0

Mountain climbing 4.5 8.8 6.0 12.9 46.5

Running or jogging 26.2 51.3 34.5 73.6 43.5

Coldwater fishing 10.4 20.3 13.6 28.9 42.8

Ice skating outdoors 5.2 10.3 6.9 14.6 42.7

Surfing 1.3 2.6 1.7 3.6 40.4

Camping developed 20.7 40.5 26.4 56.2 38.7
100 Interim Update of the 2000 RPA Assessment

Figure 67.—Area of the National Wilderness Preservation 

System by managing agency, 2002

National forests in many areas serve a unique role in providing

recreational opportunities. For example, roaded areas in natural

settings increasingly are to be found only on public lands.

Participation in recreation and tourism is a function of the

availability and supply of recreation opportunities as well as

the demand for recreation. Demand for outdoor recreation and

tourism is driven in part by population, disposable income, and

people’s tastes and preferences. For many outdoor recreation

and tourism activities, the availability of facilities determines

whether the activity is possible or not.

Implications of participation rates—A fixed land base with a

growing population and increasing demands for recreation has

many management implications, including a smaller and more

fragmented rural land base and less “connectiveness” between

people and the land. Perhaps the most important implication

is greater conflicts and competition for access to land. For

example, the public puts clean water, protection for future

generations, wildlife habitat, and naturalness at the top of their

list of most highly valued purposes for public forests (Tarrent

et al. 2003). These uses are often at odds with motorized and

resource extraction uses.

Possible future trends—Cordell (1999) presents projections

of participation by selected recreation activities. In part due to

projected rising incomes, the number of participants in most

recreation activities is projected to increase faster than the rates

of growth in population. Increased rates of participation are

expected in most activities. The expected increasing number

and diversity of the U.S. population will affect future recreation

patterns. The population is also aging and fewer people come

from a rural background.

Wilderness

Status of the system—The National Wilderness Preservation

System (System) was started in 1964 with 54 areas that totaled

11.4 million acres. Over the past decades, the System has

grown to 662 units that, as of January 2004, totaled about 106

million acres. The System is expected to continue to grow.

The System is managed by the BLM, Forest Service, U.S. Fish

and Wildlife Service, and National Park Service. The Forest

Service manages 33 percent of the total area in the System (fig.

67). The NPS has the largest area to manage—41 percent of the

total.

Alaska has 55 percent of the designated area where it accounts

for 15.9 percent of the total land area. Wilderness areas

comprised 5.8 percent of the total land area in the rest of the

West, 0.5 percent in the South, and less than 0.3 percent in the

North. Most of the growth in the number of areas and total area

in the System has been in the West where the majority of the

federally owned land is located.

The entire population of the United States lives within 400

miles of one or more wilderness areas. Nearly 17 percent live

within 25 miles, and more than two-thirds of the population

live within 100 miles of one or more wilderness areas.

Some characteristics of the system—In general, the more

diverse the elevation and other natural characteristics of the

wilderness system, the greater are their contributions toward

sustaining a variety of natural species. Not surprisingly, most of

the wilderness area at high elevation is in the West. Nationally,

about 2 percent of the total area in wilderness is above 10,000

feet and more than 40 percent is at elevations between 5,000

and 10,000 feet.
Interim Update of the 2000 RPA Assessment 101

Box 21

Off-highway vehicle participation—Since 1982, driving

motor vehicles off highways became one of the fastest

growing activities in the country: The number of participants

over 12 years of age increased by more than 100 percent

(Cordell et al. 2004). From the sample period fall 1999 to

summer 2000, to the sample period fall 2003 to fall 2004, the

number of people age 16 and over and participating at least

once in the past 12 months in off-highway motorized driving

or riding increased from 36 million to 51 million people

(table 13). In 2003–04, the number of participants amounted

to 23.2 percent of the population.

Available data indicates that most off-highway-vehicle

participants are younger than 50 years of age, male, white,

and urban. Across all demographics in table 13, the number

of people participating were increasing, except for American

Indian and Asian Pacific Islander.

Off-highway vehicle impacts—Available information

regarding the effects of off-highway vehicles is anecdotal

or based on case studies. The following impacts are from

studies on national forest lands. Noise has a negative effect

on breeding birds within about 100 meters. Off-highway

vehicles and mountain bike activities substantially increase

movement rates of elk, cause elk avoidance of use areas,

Table 13.—Millions of people in the United States age 16 

years or older participating at least once in the last 12 

months from 1999–2000 to 2003–2004 in off-road vehicle 

use.

Demographic Fall 1999– Fall 2003–

summer 2000 fall 2004

Total participating 36.0 51.0

Age—under 30 14.5 18.7

Age—30–50 15.5 23.4

Age—51 and older 5.8 9.2

Male 22.1 31.2

Female 14.1 20.1

White 29.3 39.7

Black 2.7 4.0

American Indian 0.4 0.3

Asian/Pacific Islander 1.3 0.8

Hispanic 2.8 5.7

Nonmetropolitan 10.0 13.6

Metropolitan 27.3 34.2

and reduce foraging time by elk. Off-highway vehicles emit

particulates and ozone precursors. Issues identified with

off-highway vehicle management on the national forests

of California were mainly related to natural resources (soil

erosion and trampling) and social institutions (violations of

regulations, such as off-highway vehicles going too fast).

As well as elevation, precipitation contributes to determining

the plant and animal species in wilderness ecosystems.

Arid areas receiving less than or equal to 15 inches of

annual precipitation are found in the West and comprise

about one-quarter of the total area (table 14). The West also

contains wilderness areas receiving a variety of amounts of

precipitation. Much of the wilderness area in the East receives

16 to 60 inches of precipitation.

Every acre designated as wilderness protects a number

of aspects of national systems. As a growing population

distributes itself farther and farther into the rural landscape

and as the mileage and distribution of roads rises, designated

wilderness areas will become of greater uniqueness.
102 Interim Update of the 2000 RPA Assessment

Rangeland

Production and consumption—Beef cattle and sheep consume some 431 million animal unit months of grazed forages

each year. Of this total, 86 percent comes from deeded nonirrigated lands, 7 percent comes from public grazing lands, 2

percent from irrigated grazing, and 5 percent from crop residue.

In addition to domestic livestock, wild herbivores depend on

range forage for a portion of their dietary needs. Big game populations have been stable to increasing, suggesting that range

forages are adequate for the needs of these populations.

Since much of the forage consumed by livestock is produced

from nonirrigated pasture owned by the livestock enterprises,

it is not priced in a forage market. Thus, decisions to change

forage production will be based on the likely economic return

associated with the final output such as livestock or wildlife.

The amount of forage produced on public lands that is available

for livestock consumption is set at different scales, respectively,

by allotment management plans, management-unit-level plans,

and agency strategic plans, all of which are directed by public

policy.

Forage production is not inventoried in a manner that can be

aggregated and reported upon at regional or national levels.

Use, not production, is quantified when forage consumption

estimates are derived from livestock inventories. Forage

consumption estimates derived from livestock inventories do

not include estimates of forage consumed by wild herbivores.

The demand for livestock is a function of society’s demand

for red meat. Other market commodities such as hides, wool,

tallow, and secondary products such as pharmaceuticals can

have a minor effect on demand. These demands in turn are

based largely on human population and income. In the time

since the 2000 Renewable Resources Planning Act Assessment,

per capita beef and lamb consumption in the United States

has remained constant at approximately 67 pounds and 1

pound, respectively. Consumption of pork and turkey has also

remained fairly constant. Per capita consumption of broilers

(chickens), however, steadily increased from 76.9 pounds in

2000 to 84.3 pounds in 2004.

Rangelands provide many values in addition to forage. They

contribute to meeting people’s needs for recreation, conserve

biodiversity, are sources of clean water, and provide vistas and

other amenities that many people enjoy.

Valuing grazing use of rangelands—The value of rangeland

forage is an important component of any assessment of trends

in the supply and demand for natural resources. In the United

States, numerous studies have evaluated the value of forage

in terms of private lease rates, particularly for public lands

(Bartlett et al. 2002). Private lease rates, however, do not

always represent the sum of all benefits received from the use

of forage on Federal rangelands. A rancher’s total willingness

to pay for public lands grazing extends beyond its forage value

for livestock production to include other attributes associated

with grazing permits like access rights and maintaining a

ranching lifestyle (Liffman et al. 2000). Researchers have also

Table 14.—Number of areas, acres, and percentage of acres of wilderness by precipitation amounts per year for the 

conterminous United States.

Precipitation Areas Acres Percent

(inches) (million)

0–15 146 12.9 27.6

16–30 138 9.5 20.3

31–40 101 8.8 18.7

41–60 185 9.8 20.9

61–90 63 3.5 7.5

100 + 20 2.3 5.0

Source: Daly and Taylor (2000).
Interim Update of the 2000 RPA Assessment 103

observed large variations in observed grazing costs, both within

and across regions of the United States, making it difficult to

ascertain the true value of forage use (Van Tassell et al. 1997).

Possible future trends—According to Mitchell (2000), the

supply of forage in the United States is not likely to change

significantly over the next few decades. The country’s

productive capacity should remain adequate to promote

sustainable management of U.S. rangelands, however.

Summary

Americans enjoy many values from their forest lands and

rangelands. This enjoyment is evident from timber harvest that

meets 73 percent of domestic needs for wood and wood fiber,

the provision of range forage and minerals, clean water, the

hundreds of millions of visits for recreation on forest lands and

rangelands each year, and use of these lands to satisfy cultural,

social, and spiritual needs and values. In addition, forest lands

and rangelands are used for subsistence purposes by many

people, and interest in nonwood and nonforage goods and

ecosystem services is increasing. Forest lands and rangelands

are the basis for employment for millions of people. The

availability, nature, and relative importance of these values to

society will evolve over time as the needs of society and the

character of the resources change over time. For example, the

changing cultural backgrounds and demographics of the U.S.

population will likely alter the hierarchy of values the public

holds toward public and private forest lands and rangelands.

With expectations of rising income and increased population,

there is little doubt that demands for goods and services from

our forest lands and rangelands will continue to increase.

We have every reason to believe that U.S. forest lands and

rangelands will continue to provide at least some level of goods

and services that society desires. Globalization also facilitates

worldwide movement of goods that are easily traded, such as

mineral and wood products.

Provision of other renewable resources such as water and recreation will be more dependent on management of domestic

forest lands and rangelands. Increasing demands for goods and

services from a fixed land base set the stage for continuation of

conflicts in the use and management of renewable resources.

Resource owners and managers and consumers will continue

to respond through reliance on markets and public processes to

help guide adaptive management as new resource conditions

and public opinions evolve. Increasing the area in conservation

easements and further developing markets for ecosystem services may become more common as ways to resolve conflicts

in resource use and management. Societal values, management

of private forest lands and rangelands, technological change in

the growing, processing, and use of timber products, recycling,

public land management policies, trade in timber and mineral

products and, more recently, globalization have all contributed

to the current renewable resource situation in the United States

and will likely continue to do so in the future. Developing

phenomena such as climate change and invasive species may

change the goods and services provided by U.S. forest lands

and rangelands. Rising energy prices may stimulate interest in

ethanol production from wood fiber.
104 Interim Update of the 2000 RPA Assessment
Interim Update of the 2000 RPA Assessment 105

Literature Cited

Alexander, S. 2004. Indicator 14: annual removal of nontimber

forest products compared to the level determined to be

sustainable. In: Darr, D., coord. Data report: a supplement to

the national report on sustainable forests—2003. FS-766A.

Washington, DC: U.S. Department of Agriculture (USDA),

Forest Service. http://www.fs.fed.us/research/sustain/.

(December 2006).

Alig, R.; Adams, D.; Joyce, L.; Sohngen, B. 2004. Climate

change impacts and adaptation in forestry: responses by trees

and markets. Choices. 19(3): 7-11.

Alig, R.; Adams, D.; McCarl, B. 1998. Impacts of incorporating

land exchanges between forestry and agriculture in sector

models. Journal of Agricultural and Applied Economics. 30(2/

December 1998): 389-401.

Alig, R.; Butler, B.J. 2004a. Area changes for forest cover types

in the United States, 1952 to 1997, with projections to 2050.

Gen. Tech. Rep. PNW-GTR-613. Portland, OR: USDA Forest

Service, Pacific Northwest Research Station. 106 p.

Alig, R.; Butler, B.J. 2004b. Projecting large-scale area changes

in land use and land cover for terrestrial carbon analyses.

Environmental Management. 33(4): 443-456.

Alig, R.; Lewis, D.; Swenson, J. 2005. Is forest fragmentation

driven by spatial configuration of the land quality? The case of

western Oregon. Forest Ecology and Management. 217(2/3):

266-274.

Alig, R.; Plantinga, A. 2004. Future forestland area: impacts

from population growth and other factors that affect land

values. Journal of Forestry. 102(8): 19-24.

American Forest and Paper Association. 2005. Statistics of

paper, paperboard, and wood pulp. Washington, DC. 62 p.

http://www.afandpa.org.

Askins, R.A.; Lynch, J.F.; Greenberg, R. 1990. Population

declines in migratory birds in eastern North America. Current

Ornithology. 7: 1-57.

Australian Bureau of Agricultural and Resource Economics;

Jaako Poyry Consulting. 1999. Global outlook for plantations.

Research Report 99.9. Canberra, Australia: ABARE. 107 p.

Bartlett, E.T.; Torell, L.A.; Rimbey, N.R.; Van Tassell, L.W.;

McCollum, D.W. 2002. Valuing grazing use on public land.

Journal of Range Management. 55: 426-438.

Bartos, D.L. 2001. Landscape dynamics of aspen and conifer

forests. In: Shepperd, W.D.; Binkley, D.; Bartos, D.L.;

Stohlgren, T.J.; Eskew, L.G., compilers. Sustaining aspen in

western landscapes: symposium proceedings. Proceedings

RMRS-P-18. Fort Collins, CO: USDA Forest Service, Rocky

Mountain Research Station: 5-14.

Bartos, D.L.; Ward, F.R.; Innis, G.S. 1983. Aspen succession

in the Intermountain West: a deterministic model. Gen. Tech.

Rep. GTR-INT-153. Ogden, UT: USDA Forest Service,

Intermountain Research Station. 60 p.

Bengston, D.N.; Webb, T.J.; Fan, D.P. 2004. Shifting forest

value orientation in the United States, 1980–2001: a computer

content analysis. Environmental Values. 13(3): 373-392.

Boyd, J.W.; Banzhaf, H.S. 2005. Ecosystem services and

government: the need for a new way of judging nature’s value.

Resources. 158: 16-19.

British Geological Survey. 2006. World mineral statistics:

1993–1997 and 1998–2002. http://www.bgs.ac.uk/mineralsuk/

commodity/world/home.html. (December 2006).

Brown, T.C. 1999. Past and future freshwater use in the United

States: a technical document supporting the 2000 USDA Forest

Service RPA Assessment. Gen. Tech. Rep. RMRS-GTR-39.

Fort Collins, CO: USDA Forest Service, Rocky Mountain

Research Station. 47 p.
106 Interim Update of the 2000 RPA Assessment

Brown, T.C.; Binkly, D. 1994. Effect of management on water

quality in North American forests. Gen. Tech. Rep. RM-248.

Fort Collins, CO: USDA Forest Service, Rocky Mountain

Research Station. 29 p.

Brown, T.C.; Hobbins, M.T.; Ramirez, J.A. 2005. The source of

water supply in the United States. Discussion paper DP-05-1,

RMRS-4851. Fort Collins, CO: USDA Forest Service, Rocky

Mountain Research Station. 57 p. http://www.fs.fed.us/rm/

value/docs/SourceWaterSupplyUnitedStates.pdf. (11 September

2006).

Burkett, V.R.; Wilcox, D.A.; Stottlemyer, R.; Barrow, W.; Fagre,

D.; Baron, J.; Price, J.; Nielsen, J.L.; Allen, C.D.; Peterson,

D.L.; Ruggerone, G.; Doyle, T. 2005. Nonlinear dynamics in

ecosystem response to climatic change: case studies and policy

implications. Ecological Complexity. 2: 357-394.

Butler, B.J.; Leatherberry, E.C. 2004. America’s family forest

owners. Journal of Forestry. Oct/Nov: 4-14.

Chicago Climate Exchange. 2006. CCX Market Report. iii(3).

April 1, 2006.

Ciesla, W.M.; Mason, A.C. 2005. Disturbance events in

America’s forests: an analysis of criterion 3, indicator 15 of

the Montreal Process—criteria and indicators of sustainable

forestry—2003. FHTET-05-02. Fort Collins, CO: USDA Forest

Service, Forest Health Technology Enterprise Team. 89 p.

Climate Change Science Program. 2004. Our changing planet:

the U.S. climate change science program for fiscal years 2004

and 2005. Washington, DC: U.S. Department of Commerce.

150 p.

Clutter, M.; Mendell, B.; Newman, D.; Wear, D.; Greis, J.

2005. Strategic factors driving timberland ownership changes

in the U.S. South. http://www.srs.fs.usda.gov/econ/pubs/

southernmarkets. (7 September 2006).

Conner, R.; Seidl, A.; Van Tassell, L.; Wilkins, N. 2001. United

States grasslands and related resources: an economic and

biological trends assessment. College Station, TX: Texas A&M

University Institute of Renewable Natural Resources. 170 p.

http://landinfo.tamu.edu/presentations/grasslands.cfm.

Cordell, K. 1999. Outdoor recreation in American life: a

national assessment of demand and supply trends. Champaign,

IL: Sagamore Publishing. 449 p.

Cordell, K.H.; Betz, C.T.; Green, G.T.; et al. 2004. Outdoor

recreation for 21st century America. State College, PA: Venture

Publishing. 293 p.

Cordell, K.H.; Overdevest, C. 2001. Footprints on the land:

an assessment of demographic trends and the future of natural

resources in the United States. Champaign, IL: Sagamore

Publishing. 314 p.

Coulston, J.W. 2004. Indicator 16: area and percent of forest

land subject to specific levels of air pollutants (e.g. sulfates,

nitrates, ozone) or ultraviolet B that may cause negative impacts

on the forest ecosystem. In: Darr, D.R., coord. Data report: a

supplement to the national report on sustainable forests—2003.

FS-766A. Washington, DC: USDA Forest Service. http://www.

fs.fed.us/research/sustain. (December 2006).

Daily, G., ed. 1997. Nature’s services: societal dependence on

natural ecosystems. Washington, DC: Island Press. 392 p.

Dale, V.H.; Joyce, L.A.; McNulty, S.; Neilson, R.P.; Ayres,

M.P.; Flannigan, M.D.; Hanson, P.J.; Irland, L.C.; Lugo, A.E.;

Peterson, C.J.; Simberloff, D.; Swanson, F.J.; Stocks, B.J.;

Wotton, B.M. 2001. Climate change and forest disturbances.

BioScience. 51: 723-734.

Daly, C.; Taylor, G. 2000. United States average annual precipitation, 1961–1990. Corvallis, OR: Spatial Climate Analysis

Service at Oregon State University. http://nationalatlas.gov/mld/

prism0p.html. (11 September 2006).
Interim Update of the 2000 RPA Assessment 107

Delcourt, P.A.; Delcourt, H.R. 1993. Paleoclimates, paleovegetation, and paleofloras during the Late Quaternary. In: Flora

of North America Editorial Committee, eds. Flora of North

American. New York: Oxford University Press: 71-94. Vol. 1.

Dunn, P.O.; Winkler, D.W. 1999. Climate change has affected

the breeding date of tree swallows throughout North America.

Proceedings of the Royal Society of London Series B. 266:

2487-2490.

Ellefson, P.V.; Chang, A.S.; Moulton, R.J. 1995. Regulation of

private forestry practices by State governments. Station Bulletin

605-1995. St. Paul, MN: Minnesota Agricultural Experiment

Station, University of Minnesota. 225 p.

Ellefson, P.V.; Hubbard, C.M.; Kilgore, M.A.; Granskog,

J.E., eds. 2005. Legal, institutional, and economic indicators

of forest conservation and sustainable management: review

of information available for the United States. A technical

document supporting the USDA Forest Service 2005 update of

the RPA Assessment. Gen. Tech. Rep. SRS-82. Asheville, NC:

USDA Forest Service, Southern Research Station. 221 p.

European Climate Exchange. 2006. http://www.europeanclimate

exchange.com. (7 September 2006).

Fankhauser, S. 1994. The social costs of greenhouse gas

emissions: an expected value approach. The Energy Journal.

15(2): 157-184.

Flather, C.H.; Brady, S.J.; Knowles, M.S. 1999. Wildlife

resource trends in the United States: a technical document

supporting the 2000 USDA Forest Service RPA Assessment.

Gen. Tech. Rep. RMRS-GTR-33. Fort Collins, CO: USDA

Forest Service, Rocky Mountain Research Station. 79 p.

Flather, C.H.; Knowles, M.S.; Brady, S.J. [N.d. (a)]. Population

and harvest trends of big game and small game species: a technical document supporting the interim update of the 2000 RPA

Assessment. Draft. On file with: Curtis Flather, USDA Forest

Service, Rocky Mountain Research Station, Fort Collins, CO.

Flather, C.H.; Knowles, M.S.; McNees, J. [N.d. (b)].

Geographic pattern of at-risk species: a technical document

supporting the interim update of the 2000 RPA Assessment.

On file with: USDA Forest Service, Rocky Mountain Research

Station, Fort Collins, CO.

Flather, C.H.; Ricketts, T.H.; Sieg, C.H.; Knowles, M.S.; Fay,

J.P.; McNees, J. 2004a. Criterion 1—conservation of biological

diversity—Indicator 6: the number of forest-dependent species.

In: Darr, D.R., coord. Data report: a supplement to the national

report on sustainable forests—2003. FS-766A. Washington,

DC: USDA Forest Service. http://www.fs.fed.us/research/

sustain. (December 2006).

Flather, C.H.; Ricketts, T.H.; Sieg, C.H.; Knowles, M.S.; Fay,

J.P.; McNees, J. 2004b. Criterion 1—conservation of biological

diversity—Indictor 7: the status (threatened, rare, vulnerable,

endangered, or extinct) of forest-dependent species at risk of

not maintaining viable breeding populations as determined by

legislation or scientific assessment. In: Darr, D.R., coord. Data

report: a supplement to the national report on sustainable forests—2003. FS-766A. Washington, DC: USDA Forest Service.

http://www.fs.fed.us/research/sustain. (December 2006).

Flather, C.H.; Sieg, C.H.; Knowles, M.S.; McNees, J. 2004c.

Criterion 1—conservation of biological diversity—Indicator 8: the number of forest-dependent species that occupy a

small portion of their former range. In: Darr, D.R., coord. Data

report: a supplement to the national report on sustainable forests—2003. FS-766A. Washington, DC: USDA Forest Service.

http://www.fs.fed.us/research/sustain. (December 2006).

Food and Agriculture Organization of the United Nations

(FAO). 1990. United Nations production yearbook. Rome, Italy.

FAO. 2001. Global forest resources assessment 2000: main

report. FAO forestry paper 140. Rome, Italy. 479 p.

FAO. 2005a. Press Release POP/918. http://www.un.org/News/

Press/docs/2005/pop918.doc.htm. (16 August 2006).
108 Interim Update of the 2000 RPA Assessment

FAO. 2005b. State of the world’s forests 2003. Rome, Italy:

United Nations. http://www.fao.org/forestry/site/10168. (13

September 2006).

Garber-Yonts, B. 2004. The economics of amenities and

migration in the Pacific Northwest: review of selected literature

with implications for national forest management. PNW-GTR617. Portland, OR: USDA Forest Service. 48p.

H. John Heinz III Center for Science, Economics, and the

Environment. 2002. The state of the Nation’s ecosystems:

measuring the lands, waters, and living resources of the United

States. New York: Cambridge University Press. 270 p.

H. John Heinz III Center for Science, Economics, and

the Environment. 2006. Filling the gaps—priority data

needs and key management challenges for national

reporting on ecosystem condition—summary, findings, and

recommendations. Washington, DC. 46 p.

Hagan, J.M.; Irland, L.C.; Whitman, A.A. 2005. Changing

timberland ownership in the northern forest and implications

for biodiversity. Report to the National Committee of Science

for Sustainable Forestry. MCCS-FCP-2005-1. Brunswick,

ME: Manomet Center for Conservation Sciences, Forest

Conservation Program. 25 p.

Hair, D.; Ulrich, A.H. 1964. The demand and price situation for

forest products—1964. Misc. Pub. No. 983. Washington, DC:

USDA Forest Service. 51 p.

Hansen, A.J.; Neilson, R.P.; Dale, V.H.; Flather, C.H.; Iverson,

L.R.; Currie, D.J.; Shafer, S.; Cook, R.; Bartlein, P.J. 2001.

Global change in forests: responses of species, communities,

and biomes. BioScience. 51: 765-779.

Hansen, A.J.; Rasker, R.; Maxwell, B.; Rotella, J.J.; Johnson,

J.D.; Parmenter, A.W.; Langner, U.; Cohen, W.B.; Lawrence,

R.L.; Kraska, M.P.V. 2002. Ecological causes and consequences

of demographic change in the new West. Bioscience. 52: 151-162.

Hansen, E.; Fletcher, R.; Cashore, B.; McDermont, C. 2006.

Forest certification in North America. EC 1518. Corvallis, OR:

Oregon State University Extension Service. 12 p.

Haynes, R.W., tech. coord. 2003. An analysis of the timber situation in the United States: 1952 to 2050: a technical document

supporting the 2000 USDA Forest Service RPA Assessment.

Gen. Tech. Rep. PNW-GTR-560. Portland, OR: USDA Forest

Service, Pacific Northwest Research Station. 254 p.

Haynes, R.W.; Adams, D.M.; Alig, R.J.; et al. 2006. Draft. The

2005 RPA timber assessment update. Portland, OR: USDA

Forest Service, Pacific Northwest Research Station.

Heath, L.S.; Smith, J.E. 2004. Indicator 26: total forest

ecosystem biomass and carbon pool, and if appropriate, by

forest type, age class, and successional changes. In: Darr, D.R.,

coord. Data report: a supplement to the national report on

sustainable forests—2003. FS-766A. Washington, DC: USDA

Forest Service. http://www.fs.fed.us/research/sustain. (25

August 2006).

Hill, B.T. 1998. Western national forests: catastrophic wildfires

threaten resources and communities. GAO/T-RCED-99-79.

Testimony before the Subcommittee on Forests and Forest

Health, Committee on Resources, House of Representatives.

Washington, DC: U.S. General Accounting Office. 23 p.

Hof, J.; Flather, C.; Baltic, T.; King, R. 2006. Nonparametric

projections of forest and rangeland condition indicators: a

technical document supporting the USDA Forest Service 2005

update of the RPA Assessment. Gen. Tech. Rep. RMRS-GTR166. Fort Collins, CO: USDA Forest Service, Rocky Mountain

Research Station. 39 p.

Hutson, S.S.; Barber, N.L.; Kenny, J.F.; et al. 2004. Estimated

use of water in the United States in 2000. USGS Circular 1268.

Denver, CO: U.S. Geological Survey. http://water.usgs.gov/

pubs/circ/2004/circ1268. (25 August 2006).
Interim Update of the 2000 RPA Assessment 109

Ince, P.; Schuler, A.; Luppold, B.; Durback, I. [N.d.]

Globalization and structural change in the U.S. forest sector:

an evolving context for sustainable forest management. Draft.

On file with: Peter Ince, USDA Forest Service, Forest Products

Laboratory, Madison, WI.

Intergovernmental Panel on Climate Change (IPCC).

2001. Climate change 2001: synthesis report, summary for

policymakers. Cambridge, UK; New York, NY: Cambridge

University Press. 398 p.

Johnson, K.M.; Stewart, S.I. 2005. Recreation, amenity

migration and urban proximity. In: Green, G.G.P.; Deller, S.C.;

and Marcouiller, D.W., eds. Amenities and rural development.

Northampton, MA: Edward Elgar: 177-196.

Jones, E.T.; McLain, R.J.; Weigand, J., eds. 2002. Nontimber

forest products in the United States. Lawrence, KS: University

Press of Kansas. 445 p.

Joyce, L.A.; Birdsey, R., tech. eds. 2000. The impact of climate

change on America’s forests: a technical document supporting

the 2000 USDA Forest Service RPA Assessment. Gen. Tech.

Rep. RMRS-GTR-59. Fort Collins, CO: USDA Forest Service,

Rocky Mountain Research Station. 133 p.

Joyce, L.A.; Laskowski, M. 2006. Natural resource managers

respond to climate change: a look at actions, challenges, and

trends. In: Price, M.F., ed. Global change in mountain regions.

Duncow: Sapiens Publishing.

Kay, C.E. 1997. Is aspen doomed? Journal of Forestry. 95(5):

4-11.

Keegan, C.E.; Morgan, T.A.; Gebert, K.M.; et al. 2004. Timber

processing capacity and capabilities in the western United

States. Unpublished. Report on file with USDA Forest Service,

Research and Development, Washington Office.

Kerns, B.K.; Liegel, L.; Pilz, D.; Alexander, S.J. 2002.

Biological inventory and monitoring. In: Jones, E.T.; McLain,

R.J.; Weigand, J., eds. Nontimber forest products in the United

States. Lawrence, KS: University Press of Kansas: 237-269.

Kline, J.D.; Alig, R.J.; Garber-Yonts, B. 2004. Forestland social

values and open space preservation. Journal of Forestry. 102(8):

39-45.

Lepczyk, C.A.; Flather, C.H.; Radeloff, V.C.; Pidgeon, A.M.;

Hamer, R.B.; Liu, J. In review. Human impacts on regional

avian diversity and abundance. Conservation Biology.

Lewis, J.W. 2002. Mapping risk from forest insects and

diseases. FS-754. Washington, DC: USDA Forest Service.

http://www.fs.fed.us/foresthealth/pubsindex.shtml.

Liffman, R.H.; Huntsinger, L.; Forero, L.C. 2000. To ranch

or not to ranch: home on the urban range? Journal of Range

Management. 53: 362-370.

Lippke, B.; Wilson, J.; Perez-Garcia, J.; Bowyer, J.; Meil, J.

2004. CORRIM: life-cycle environmental performance of

renewable building materials. Forest Product Journal. 54(6):

8-19. http://www.corrim.org/reports/pdfs/FPJ_Sept2004.pdf.

Maestas, J.D.; Knight, R.L.; Gilbert, W.C. 2003. Biodiversity

across a rural land-use gradient. Conservation Biology. 17:

1425-1434.

Manier, D.J.; Laven, R.D. 2002. Changes in landscape patterns

associated with the persistence of aspen (Populus tremuloides 

Michx.) on the western slope of the Rocky Mountains,

Colorado. Forest Ecology and Management. 167: 263-284.

Meehl, G.A.; Washington, W.M.; Collins, W.D.; Arblaster, J.M.;

Hu, A.; Buja, L.E.; Strand, W.G.; Teng, H. 2005. How much more

global warming and sea level rise? Science. 307: 1769-1772.

Minnesota IMPLAN Group, Inc. 1997. IMPLAN professional

social accounting and impact analysis software: user’s, analysis

and data guide. Stillwater, MN: Minnesota IMPLAN Group. 

378 p. http://www.implan.com.
110 Interim Update of the 2000 RPA Assessment

Mitchell, J.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: USDA Forest Service, Rocky Mountain

Research Station. 84 p.

Mitchell, J.E.; Wallace, G. 1998. Managing grazing and

recreation across boundaries in the Big Cimarron watershed.

In: Knight, R.L.; Landres, P.B., eds. Stewardship across

boundaries. Washington, DC: Island Press: 217-236.

National Research Council. 1997. Forested landscapes in

perspective: prospects and opportunities for sustainable

management of America’s non-Federal lands. Washington, DC:

National Academy Press. 249 p.

National Research Council. 2005. Valuing ecosystem services:

toward better environmental decisionmaking. Washington, DC:

National Academy Press. 277 p.

Nowak, D.J.; Crane, D.E. 2002. Carbon storage and

sequestration by urban trees in the United States.

Environmental Pollution. 116: 381-389.

Nowak, D.J.; Crane, D.E.; Dwyer, J.F. 2002. Compensatory

value of urban trees in the United States. Journal of

Arboriculture. 28(4): 194-199.

Nowak, D.J.; Walton, J.T. 2005. Projected urban growth (2000–

2050) and its estimated impact on the U.S. forest resource.

Journal of Forestry. 103(8): 383-389.

Nowak, D.J.; Walton, J.T.; Dwyer, J.F.; et al. 2005. The

increasing influence of urban environments on U.S. forest

management. Journal of Forestry. 103(8): 377-382.

O’Neill, K.P.; Amacher, M.C. 2004a. Criteria 4—Indicator 18:

area and percent of forest land with significant soil erosion. In:

Darr, D.R., coord. Data report: a supplement to the national

report on sustainable forests—2003. FS-766A. Washington,

DC: USDA Forest Service. http://www.fs.fed.us/research/

sustain. (December 2006).

O’Neill, K.P.; Amacher, M.C. 2004b. Criteria 4—Indicator 21:

area and percent of forest land with significantly diminished

soil organic matter and/or changes in other soil chemical

properties. In: Darr, D.R., coord. Data report: a supplement

to the national report on sustainable forests—2003. FS-766A.

Washington, DC: USDA Forest Service. http://www.fs.fed.us/

research/sustain. (December 2006).

O’Neill, K.P.; Amacher, M.C. 2004c. Criteria 4—Indicator 22:

area and percent of forest land with significant compaction

or changes in soil physical properties resulting from human

activities. In: Darr, D.R., coord. Data report: a supplement to

the national report on sustainable forests—2003. FS-766A.

Washington, DC: USDA Forest Service. http://www.fs.fed.us/

research/sustain. (December 2006).

O’Neill, K.P.; Amacher, M.C. 2004d. Criteria 4—Indicator 25:

area and percent of forest land experiencing an accumulation of

persistent toxic substances. In: Darr, D.R., coord. Data report: a

supplement to the national report on sustainable forests—2003.

FS-766A. Washington, DC: USDA Forest Service. http://www.

fs.fed.us/research/sustain. (December 2006).

Outdoor Recreation Resources Review Commission (ORRRC).

1962. National recreation survey. Outdoor Recreation

Resources Review Commission study report 19. Washington,

DC: Island Press.

Parmesan, C. 1996. Climate and species’ range. Nature. 382:

765-766.

Parmesan, C.; Galbraith, H. 2004. Observed impacts of global

climate change in the United States. Arlington, VA: Pew Center

for Climate Change. 56 p.

Parmesan, C.; Yobe, G. 2003. A globally coherent fingerprint

of climate change impacts across natural systems. Nature. 42:

37-42.

Random Lengths. 2006. Officials decry, support lumber trade

deal. In: Random Lengths. Eugene, OR: Random Lengths

Publications. 62(18).
Interim Update of the 2000 RPA Assessment 111

Rappaport, J.; Sachs, J.D. 2003. The United States as a coastal

nation. Journal of Economic Growth. 8: 5-46.

Renewable Fuels Association. 2006. From niche to Nation—

ethanol industry outlook 2006. Washington, DC. 24 p.

Riitters, K.H.; Coulston, J.W.; Wickham, J.D. 2003. Localizing

national fragmentation statistics with forest type maps. Journal

of Forestry. 101: 18-22.

Riitters, K.H.; Wickham, J.D.; Coulston, J.W. 2004. Use of

road maps in national assessments of forest fragmentation in

the United States. Ecology and Society. 9(2): 13. http://www.

ecologyandsociety.org/vol9/iss2/art13.

Riitters, K.H.; Wickham, J.D.; O’Neill, R.V.; Jones, K.B.;

Smith, E.R.; Coulston, J.W.; Wade, T.G.; Smith, J.H. 2002.

Fragmentation of continental United States forests. Ecosystems.

5: 815-822.

Robbins, C.S.; Saur, J.R.; Greenberg, R.S.; Droege, S.1989.

Population declines in North American birds that migrate to the

neotropics. Proceedings of the National Academy of Science

(USA). 86: 7658-7662.

Saur, J.R.; Hines, J.E.; Fallon, J. 2005. The North American

breeding bird survey: results and analysis 1966-2004. Version

2005.2. Laurel, MD: USGS Patuxent Wildlife Research Center.

http://www.mbr-pwrc.usgs.gov/bbs/bbs.html.

Scott, J.M.; Abbitt, R.J.F.; Groves, C.R. 2001. What are we

protecting? Conservation in Practice. 2: 18-19.

Sedell, J.; Sharpe, M.; Apple, D.D.; et al. 2000. Water and

the Forest Service. FS-660. Washington, DC: USDA Forest

Service. 40 p.

Sere, C.; Steinfeld, H. 1996. World livestock production

systems: current status, issues, and trends. Animal Production

and Health Paper 127. Rome, Italy: Food and Agriculture

Organization of the United Nations. 82 p.

Shriner, D.S.; Street, R.B.; et al. 1998. North America. In:

Watson, R.T.; Zinyowera, M.C.; Moss, R.H., eds. The regional

impacts of climate change. Cambridge: Cambridge University

Press: 255-330.

Sieg, C.H.; Flather, C.H.; Barstatis, N. 2004. Criterion 1—

conservation of biological diversity—Indicator 9: population

levels of representative species from diverse habitats monitored

across their range. In: Darr, D.R., coord. Data report: a

supplement to the national report on sustainable forests—2003.

FS-766A. Washington, DC: USDA Forest Service. http://www.

fs.fed.us/research/sustain.

Sieg, C.H.; Flather, C.H.; Barstatis, N.; Fowler, J.F.; et al.

2005. Exotic plant richness as an indicator of ecosystem

health: an update to support the 2005 update of the 2000 RPA

Assessment. Draft. On file with: Carolyn Seig, USDA Forest

Service, Rocky Mountain Research Station, Flagstaff, AZ.

Skog, K.E.; Abt, K.; Alexander, S. 2004. Indicator 44: direct

and indirect employment in the forest sector and the forest

sector employment as a proportion of total employment. In:

Darr, D.R., coord. Data report: a supplement to the national

report on sustainable forests—2003. FS-766A.Washington, DC:

USDA Forest Service. http://www.fs.fed.us/research/sustain.

(December 2006).

Smith, B.W.; Miles, P.D.; Vissage, J.S.; Pugh, S.A. 2004. Forest

resources of the United States, 2002: a technical document

supporting the USDA Forest Service 2005 update of the RPA

Assessment. Gen. Tech. Rep. NC-GTR-241. St. Paul, MN:

USDA Forest Service, North Central Research Station. 137 p.

Stapanium, M.A.; Sundberg, S.D.; Baumgardner, G.A.; Liston,

A. 1998. Alien plant species composition and associations with

anthropogenic disturbance in North American forests. Plant

Ecology. 136: 49-62.

Stein, S.M.; McRoberts, R.E.; Alig, R.J.; et al. 2005. Forests

on the edge: housing development on America’s private forests.

Gen. Tech. Rep. PNW-GTR-636. Portland, OR: USDA Forest

Service, Pacific Northwest Research Station. 16 p.
112 Interim Update of the 2000 RPA Assessment

Stokstad, E. 2005. What’s wrong with the Endangered Species

Act? Science. 309: 2150-2152.

Sulak, A.; Huntsinger, L. 2002. Sierra Nevada grazing in transition: the role of Forest Service grazing in the foothill ranches of

California. A report to Sierra Nevada Alliance, California Cattlemen’s Association, and California Rangeland Trust. Berkeley,

CA: University of California, Berkeley.

Tarrent, M.A.; Cordell, H.K.; Green, G.T. 2003. PVF: a scale

to measure public values of forests. Journal of Forestry. 101(6):

24-30.

Theobald, D.M. 2001. Land-use dynamics beyond the American

urban fringes. Geographical Review. 91: 544-564.

United Nations Economic Commission for Europe; Food and

Agriculture Organization of the United Nations. 2000. Forest

resources of Europe, CIS, North America, Australia, Japan, and

New Zealand. UN-ECE/FAO contribution to the global forest

resource assessment 2000. Main Report. New York: United

Nations. 445 p.

U.S. Bureau of the Census. 2004. National population

projections. http://www.census.gov/population/www/

projections/natsum-T1.html.

U.S. Bureau of the Census. 2005. World population 1950 to

2050. http://www.census.gov/pc/www/worldpop.html.

U.S. Bureau of the Census. 2006. Annual population estimates

2000 to 2005: annual estimates of the population for the United

States and States, and for Puerto Rico: April 1, 2000 to July 1,

2005. http://www.census.gov/popest/states/NST-ann-est.html.

(24 August 2006).

U.S. Environmental Protection Agency. 2003. Draft report on

the environment 2003. EPA 600-R-03-050. Washington, DC.

www.epa.gov/indicators.

USDA Forest Service. 2001. 2000 RPA assessment of forest

and rangelands. FS-687. Washington, DC. 78 p.

USDA Forest Service. 2004. National report on sustainable

forests—2003. FS-766. Washington, DC. 139 p.

USDA Forest Service Fire Sciences Laboratory. 1999a. Current

condition classes v1.0. Unpublished database. On file with

USDA Forest Service, Rocky Mountain Research Station,

Missoula, MT. http://www.fs.fed.us/fire/fuelman.

USDA Forest Service Fire Sciences Laboratory. 1999b. Historic

natural fire regimes v3.0. Unpublished database. On file with

USDA Forest Service, Rocky Mountain Research Station,

Missoula, MT. http://www.fs.fed.us/fire/fuelman.

USDA Natural Resources Conservation Services (NRCS).

2000. National resources inventory. Washington, DC. http://

www.nrcs.usda.gov/technical/NRI/1997/summary_report.

(December 2006).

Van Tassell, L.W.; Bartlett, E.T.; Mitchell, J.E. 2001. Projected

use of grazed forages in the United States: 2000 to 2050: a

technical document supporting the 2000 USDA Forest Service

RPA Assessment. Gen. Tech. Rep. RMRS-GTR-82. Fort

Collins, CO: USDA Forest Service, Rocky Mountain Research

Station. 73 p.

Van Tassell, L.W.; Torell, L.A.; Rimbey, N.R.; Bartlett, E.T.

1997. Comparison of forage value on private and public grazing

leases. Journal of Range Management. 50: 300-306.

Vesterby, M.; Krupa, K.S. 2001. Major land uses of the United

States, 1997. ERS Statistical Bulletin No. 973. Washington,

DC: USDA Economic Research Service. 54 p.

Westbrooks, R.C. 1998. Invasive plants, changing the landscape

of America: fact book. Washington, DC: Federal Interagency

Committee for the Management of Noxious and Exotic Weeds.

109 p.

Williams, K.; Ewel, K.C.; Stumpf, R.P.; Putz, F.E.; Workman,

T.W. 1999. Sea-level rise and coastal forest retreat on the West

Coast of Florida, USA. Ecology. 80: 2045-2063.
Interim Update of the 2000 RPA Assessment 113

Wood Products Council. 1999. Wood used in mew residential

construction—1998 and 1995. Tacoma, WA: APA—The

Engineered Wood Association. 154 p.

World Commission on Environment and Development. 1987.

Our common future. Oxford, UK: Oxford University Press. 54 p.

World Resources Institute. 2003. Millennium ecosystem

assessment. Washington, DC: Island Press. 245 p.

World Resources Institute; United Nations Environment

Programme; United Nations Development Programme; World

Bank. 1998. World resources 1998–99. New York. 369 p.


United States Department of Agriculture

Forest Service

FS-874

April 2007

http://www.fs.fed.us/research/rpa/
Interim Update of the 2000 Renewable Resources Planning Act Assessment

2007