United States

Department of

Agriculture

Forest Service

Pacific Northwest

Research Station

General Technical

Report

PNW-GTR-416

December 1997

Forest Sustainability: An

Approach to Definition

and Assessment at the

Landscape Level

Michael P. Amaranthus
MICHAEL P. AMARANTHUS is a research biologist, Pacific Northwest Research

Station, stationed at Siskiyou National Forest, Box 440, Grants Pass, OR 97526.

Author
Amaranthus, Michael P. 1997. Forest sustainability: an approach to definition and

assessment. Gen. Tech. Rep. PNW-GTR-416. Portland OR: U.S. Department of

Agriculture, Forest Service, Pacific Northwest Research Station. 14 p.

Forest sustainability is a concept for the desired condition of forest ecosystems all

over the world. The essential aspects of sustainable forests differ tremendously,

however, among peoples of the world. Parks and wilderness areas, wildlife preserves,

watershed protection areas, multiple-use forestry, and short-rotation tree farming all

are sustainable, from some viewpoints, when inflows and outflows balance over time.

Sustainability needs to be defined to minimize conflict, confusion, and mistrust. For

what, where, whom, and how long are forest values being sustained? One recommended approach is to assess sustainability at the landscape level and define the

processes, structures, and resources needed to meet many of society’s objectives.

A landscape-level example in the 200 000-hectare Applegate watershed in southwest

Oregon uses four criteria as a measure of sustainability. With these criteria, management objectives, activities, and monitoring measures can be implemented across the

watershed. Managers and policymakers must recognize that modern forest practices

have a short history and there is little documentation of long-term effects. Increased

efforts are needed for well-designed, long-term, and integrated approaches for

monitoring forest sustainability.

Keywords: Applegate watershed, landscape level, forest management, social values,

spatial and temporal scales, sustainability.

Abstract
Contents 1 Introduction

1 Sustainability of What?

3 Sustainable Where?

5 Sustainable for Whom?

5 Sustainable for How Long?

7 Defining Sustainability

10 A Landscape Example

12 Conclusions

12 Acknowledgments

13 Literature Cited
1

Forest sustainability is a concept for the desired condition of forest ecosystems all over

the world. Although the term “sustainable forestry” is used frequently, it is seldom

defined. The essential aspects of sustainable forests differ tremendously among and

within peoples of the world. Parks and wilderness areas, wildlife preserves, watershed

protection areas, multiple-use forestry, and short-rotation tree farming all are sustainable, from some viewpoints, when inflows and outflows balance over time. Individual

views of forest sustainability differ widely and depend on various ecosystem perspectives, uses, and spatial and temporal scales. For what, where, whom, and how long

are forest values being sustained? Once specific definitions are made, management

objectives, activities, and monitoring measures can be implemented.

Although people want to sustain forests, differences and misunderstandings often arise

about what features should be sustained. Sustainability can range from commodity

outputs to spiritual values, from individual mushrooms to whole forest ecosystems

(fig. 1). The features used as a measure of sustainability reflect the needs and backgrounds of the people involved: fiber production may be the feature most important to

the industrial landowner, but a forester working in a wilderness area on public lands

may place a higher value on biodiversity. Regional and national differences can be

great: an artist in New York City may value visual quality, whereas a cabinet maker in

Oregon may place a high value on wood quality. Villagers from the mountains of Nepal

may value coppiced fuelwood, fodder, and green manure for their fields, but a rural

resident in the mountains of California may value the recreation industry associated

with old-growth forests.

Utilitarian perspectives often dictate what is to be sustained (Monnig and Byler 1992).

For example, insect- and fungus-related disturbance and mortality are integral parts of

how forests normally function, with many species dependent on and adapted to forest

senescence, decay, and disturbance (Bormann and Likens 1979). Yet most groups

would consider these organisms to be destroying forests rather than sustaining them.

Far from being negatives, these organisms tend to renew and diversify forest stands

and landscapes, if their disturbance-related activities do not become too severe or

occur too frequently (fig. 2) (Perry and others 1989).

What practices are sustainable? Sustainable forestry practices often include a “tool kit”

of actions with which people modify the forest to perpetuate desired features.

Throughout the Western United States, forest thinning and other density-management

projects are often considered sustainable forestry practices. Although density management can be an excellent tool to increase the vigor of an existing stand and reduce

susceptibility to bark beetle attack, thinning is not synonymous with forest sustainability.

A commercial thinning project may do little for the sustainability of organisms that thrive

at high basal areas or high canopy closure, or rely on inputs of dead trees (fig. 3).

Similarly, commercial thinning and other vegetation removal can reduce fuel loadings,

continuity, and fire risk but do little for organisms that rely on high levels of forest

structure and canopy or are shade intolerant (FEMAT 1993, Thomas and others 1993).

Prescribed underburning is another forestry practice perceived as “sustainable”

throughout much of the Western United States. Although burning can be an effective

tool to reduce fuel levels and thin forest stands, loss of coarse woody debris due to fire

can impact populations of small mammals (Harmon and others 1986). In addition,

Introduction

Sustainability

of What?
2

Figure 1—Sustainability measures differ widely, from

commodity to aesthetic and other values: (A) Forest

harvest in Gifford Pinchot National Forest, southwest

Washington (photo by Jim White); (B) admiring oldgrowth redwood tree in Redwood National Park,

northwest California

Figure 2—Disease organisms can

promote forest structure: (A)

Fomitopsis pinicola fruiting body

and; (B) resulting gap in forest

canopy with regenerating trees,

Umpqua National Forest, southern

Oregon.

A B

A B
3

burning can result in erosion and increased distribution of nonnative species

(Amaranthus and others 1993). Clearly, the selection of sustainable forestry practices

depends on what one is trying to sustain.

The term “forest sustainability” can be applied to stands, landscapes, and regions.

Thus, understanding how forests function at different spatial scales is critical to assess

the impact of any management activity on sustainability. For the most part,

sustainability concepts have developed at the level of individual organisms and have

not been applied effectively at the landscape level. For example, insects and pathogens may increase the quality of habitat for organisms requiring high levels of coarse

woody debris at the stand scale, but they may create a landscape and regional environment vulnerable to catastrophic fires that could affect the existence of those same

organisms when viewed at a larger scale. Many practices can create one condition at

the stand scale and a different one at a landscape or regional scale (fig. 4). Protecting

excessive levels of forest structure and coarse woody debris may mean healthy habitat

for dependent organisms at the stand scale, but when viewed in the landscape scale, it

may create an environment that magnifies the spread and intensity of uncontrolled fire.

Site productivity often is used as a criterion for evaluating sustainable forestry. Site

productivity emphasizes a stand-level view of sustainability, focusing on the productive

capacity of forest sites and most often referring to vegetative production, soil fertility,

and other considerations at the stand level. Impacts to sustainability such as soil

erosion, nutrient depletion, and compaction also are evaluated at the stand level (Dyck

and Mees 1990). By comparison, a regional approach to sustainability emerges in the

Northwest Forest Plan covering large areas of California, Oregon, and Washington

(Species Analysis Team 1994). Sustainability issues focus on late-successional forest

species, especially the northern spotted owl (Strix occidentalis) that can be understood

only with landscape and regional approaches. Moreover, the Northwest Forest Plan

reflects relative national priorities between wood production and preservation of endangered species. This approach, in which massive allocations of public lands are off

limits to any logging activity, emphasizes sustainability in terms of certain wildlife

species, aesthetics, and water quality. Such a large-scale approach, however, can

constrain wood supplies and human needs for shelter and fuel (Koch 1992). Unforeseen consequences can result when forest management and timber supplies are

discouraged or constrained at this scale. These include the conversion of private forest

land to nonforest uses and increased use of nonrenewable substitutes for wood

products (Bowyer 1992).

Measures of forest sustainability get increasingly more complex as one moves from

individual organisms and stands to landscapes (fig. 5). Sustainability of the growth of

an individual tree can be evaluated simply by height and diameter measurements and

external examination of crown conditions. At the stand or landscape level,

sustainability qualities expand to include soil and water protection, wildlife habitat,

disturbance effects, and many other features not dependent on the sustained growth of

all trees and, in fact, requiring the mortality of individual trees (Bisson and others 1987,

Thomas and others 1993). Defining the spatial scale being evaluated reduces opportunities for confusion.

Sustainable Where?
4

Figure 3—Throughout the Western United

States, forest thinning and other densitymanagement projects are often considered

sustainable forestry practices: (A) Recently

thinned mixed-conifer stand, Rogue River

National Forest, southwest Oregon,

increases tree vigor and reduces canopy

cover; some organisms in the area, however,

such as the (B) California red backed vole

(Clethnonomys occidentalis), require habitat

with dense canopy cover.

Figure 4—Retaining coarse woody debris is considered a sustainable

practice at the stand scale but, when viewed at the landscape scale,

may create an environment that magnifies the spread and intensity of

uncontrolled fire: (A) High levels of coarse woody debris left for

wildlife habitat in mixed-conifer stand (B) stand-replacing wildfire; and

(C) resulting stand condition following wildfire, Siskiyou National

Forest, southwest Oregon.

A B

A

B C
5

Sustainability has several meanings and most often reflects the values of those

involved. Sustainability depends on what people want and this is often clouded with

controversy, because one view often represents one group’s particular values at the

expense of others (fig. 6 ). Whether a forest practice enhances sustainability depends

on the cultural “lens” that influences how people think and the nature of their work. No

one version of the sustainable forest is correct. A resource specialist concerned about

declining late-successional habitat or salmon habitat may not view prescribed burning

as a sustainable forestry practice. A wildlife biologist studying snag-dependent species

may view a landscape recently affected by bark-beetle mortality as adding to the

sustainability of the forest. A commercial mushroom picker may see decomposing

woody material as a moisture source for the sustained production of his favorite fungal

species. A fuel specialist may view the same piece of wood as a fire hazard and risk

and not sustainable. A villager may see a continual source of fuelwood.

Over time, what people need, want, and can do changes; this is reflected in the forest

values they seek to sustain. In the Pacific Northwest United States, the emphasis of

National Forest management has shifted over the years from watershed protection to

fiber production to conservation of biological diversity. Even at a particular time, human

interests often differ depending on ownership and locality of the forest resources

(Romm and Washburn 1987). Local, state, and national governments often disagree

on how forests should be managed and which resources are important to sustain.

Most modern forest management practices have a short history and little documentation of long-term effects on forest sustainability (Powers and Van Cleve 1991). Much

effort has focused on predicting forest responses via models. Few models, however,

actually test the sustainability of resources that are not traded in the marketplace or

that use comprehensive data sets collected during the period relevant to the predicted

outcome (Franklin and others 1989). Knowledge of the long-term effects of forest

management practices on basic forest resources, such as soil productivity, water

quality and quantity, biodiversity, and wood production, are clearly needed. Forest

phenomena can occur on time scales of seasons, decades, and centuries. Short-term

results, chronosequence, and retrospective studies may mask the real sustainability of

the forest and lead to erroneous conclusions and serious management mistakes

(Magnuson 1990).

Forest ecosystems are slow to develop and subject to complexities that confound

measures of sustainability. Changes in sustainability thus may not be recognized

without long-term measurements. Forest soil formation is slow, requiring many centuries to millenia; coarse woody debris can take several centuries to decompose (Sollins

and others 1980). Several rotations may be necessary to determine if the system is

losing, gaining, or cycling nutrients and organic matter (Miller and others 1988). Over

the long term, cumulative effects can result from the incremental impact of a forestry

practice that results in individually minor but collectively significant actions over time

(Gosselink and others 1990) For example, loss of soil productivity can result from the

continuous removal of the forest floor: these may be individually minor actions but

collectively a significant action over a long period (fig. 7). Several tree rotations may be

necessary to assess the sustainability of practices.

Sustainable

for Whom?

Sustainable

for How Long?
6

Figure 5—Measures of forest sustainability get increasingly more complex as one moves from individual organisms and stands to

landscapes: (A) Evaluating individual tree diameter and (B) landscape view of mix of forest habitats in managed forests of central

Cascade Range in Oregon.

Figure 6—Protesting a timber sale at the Siskiyou National Forest headquarters

in southwest Oregon (photo by Robert Ettner).

A

B
7

Many processes in forest ecosystems are subject to considerable annual variability,

such that systematic long-term monitoring is necessary to determine whether year-toyear variations during these periods are unidirectional, cyclic, time-lag, or episodic, or

reflect other trends (Waring and Schlesinger 1985). Observations of sustainability can

be confounded by the timing and pattern of disturbance processes, such as insects,

windfall, or fires, that are greatly influenced by human activities (Franklin and others

1989). Comparisons of wildfire activity early and late in the 20th century in the Siskiyou

National Forest, southern Oregon, illustrate different levels and patterns of disturbance

(table 1). The period between 1915 to 1940 had three times more hectares burned

annually compared to the 1970-94 period. This probably reflects a high level of arsonrelated fires during the 1915-40 period and less fire supression capability compared to

the 1970-94 period. The 1970-93 period had an episodic pattern of wildfire activity with

almost 90 percent of the total hectares burned in just one year. Extreme wildfire years,

such as 1987, may result from a combination of factors: the episodic nature of fire

weather conditions; decades of effective suppression activities that result in increased

fuel levels, fire intensity, and rates of spread when fire suppression capabilities are

overwhelmed; interactions of other disturbance agents, such as bark beetles, that

increase tree mortality and fuel levels; and landscape vegetative patterns caused by

management practices. Failure to assess episotic events with long-term study may

limit understanding of factors influencing sustainability. In addition, time-lag effects of

previous practices also may influence sustainability measures, such as forest productivity or soil fertility. Native Americans used fire extensively in the period before European settlement, and extensive burning by miners and settlers before 1915 confound

current efforts to define baseline estimates of sustainability. How often disturbances

occur and how they influence sustainability require long-term studies; foresters, biologists, managers, and policymakers must recognize that sustainability of forests and

forest practices depends on a temporal scale seldom considered.

If forest sustainability is to be used as a desired goal for forested lands, it is important

to specify what it implies and how it will be evaluated. The World Commission on

Environment and Development (1987) considers sustainable forestry as the balancing

of ecology and economics to current human needs while protecting the ability of future

generations to meet their needs. Unfortunately, this definition lacks the clarity and

specificity needed for evaluation. How would such a definition be measured? Are

balanced forestry uses the only sustainable forest practices? At what scale is

sustainability evaluated? What is meant by human needs? Are current levels of

human needs realistic and sustainable?

A useful definition of forest sustainability is presented by Kolb and others (1994); it

specifically identifies the products, structures, and resources needed to support healthy

forests in the sense of satisfying at least some of the objectives of society. This definition considers a healthy forest to have the following four characteristics that relate to

forest sustainability: (1) the physical environment, biotic resources, and trophic networks to support productive forests; (2) resistance to catastrophic change and the

ability to recover on the landscape level; (3) a functional equilibrium between supply

and demand of essential resources (water, nutrients, light, and growing space) for

major portions of the vegetation; and (4) a diversity of seral stages and stand structures

that provide habitat for any native species and all essential ecosystem processes.

Defining

Sustainability
8

Figure 7—Over the long term, cumulative effects can result from the incremental

impact of a forestry practice that results in individually minor but collectively

significant actions over time: (A) Northern Thailand pine stand with forest floor

bare following pine needle removal and (B) bundles of pine needles being

hauled to market.

A

B
9

Table 1—Hectares burned by wildfires, Siskiyou Natonal Forest,

1915-40 and 1960-94

Year Area burned Year Area burned

Hectares Hectares

1915 4227 1970 304

1916 5723 1971 408

1917 42687 1972 89

1918 18298 1973 72

1919 * 1974 16

1920 314 1975 204

1921 1376 1976 10

1922 1854 1977 15

1923 1014 1978 15

1924 7795 1979 49

1925 * 1980 39

1926 * 1981 2

1927 27 1982 60

1928 * 1983 8

1930 9308 1984 14

1931 9018 1985 144

1932 14610 1986 6

1933 263 1987 45377

1934 1244 1988 13

1935 1201 1989 4

1936 5011 1990 932

1937 643 1991 21

1938 20549 1992 18

1939 5368 1993 3

1940 837 1994 3157

 Total 151366 Total 50981

Average per year 6880 Average per year 2039

* = data not available.
10

The Applegate watershed in southern Oregon is a 200 000-hectare landscape containing a mix of private, state, and Federal ownerships that range in elevation between 50

and 2000 meters (fig. 8). Applegate forests are occupied by a complex array of conifer

and hardwood forests supporting a rich mix of plant and animal species. About 13,000

people live in the watershed, mostly in the lower elevations and near to the forest

interface. The four sustainability characteristics in Kolb and others (1994) can be used

to assess forest sustainability in the Applegate watershed.

1. The physical environment, biotic resources, and trophic networks to support

productive forests.

Over most of the Applegate watershed, the physical, biotic, and tropic networks are

intact to support the forest ecosystem. There are some exceptions at the stand level:

highly eroded or steep raveling areas, aggraded stream reaches, and high-elevation,

old, nonreforested clearcuts. These areas, however, occupy less than 3 percent of the

entire watershed. Based on this criterion, the forests of the Applegate watershed are

probably in a sustainable condition.

2. Resistance to catastrophic change and the ability to recover on the landscape

level.

A significant threat of catastrophic disturbance exists within the Applegate watershed

that could dramatically alter plant and animal structure and composition. Bark beetle

hazard is high across large portions of the watershed with risk extreme in many areas

(fig. 9). These insects are known to reach outbreak levels when stand density exceeds

the carrying capacity of sites across large areas. In addition, high levels of fuels, stand

density, increasing mortality, and urban encroachment have increased the risk of

intense wildfire over the next several decades. Natural rates of fire frequency indicate

that much of the area has missed two to five fire cycles. In its current state, the

Applegate landscape will magnify rather than resist the catastrophic effects of disturbance. Suburban encroachment, forest clearing, and changes in land use within the

watershed have reduced the ability of the area to recover. Based on the second

criterion, the forests of the Applegate watershed are probably not in a sustainable

condition.

3. A functional equilibrium between supply and demand of essential resources.

Stagnant, overstocked stands of low vigor are characteristic across the Applegate

watershed. Nutrient cycling is low because of fire-suppression activities. Larger, older

trees are rapidly dying because of intense competition with dense understory vegetation. Streamflows have declined across the landscape owing to increased evapotranspirational demand upslope and water withdrawals. These factors indicate a major

imbalance between demand and supply of water, nutrients, and growing space for

some important vegetative components (fig. 10). Based on the third criterion, the

forests of the Applegate watershed are probably not in a sustainable condition.

A Landscape

Example
11

Figure 8—A landscape view of the Applegate

watershed (photo by Robert Ettner).

Figure 9—Recent bark beetle mortality in the

Applegate watershed.

Figure 10—Dense, stagnant 120-

year-old Douglas-fir stand in the

Applegate watershed.
12

4. A diversity of seral stages and stand structures that provide habitat for any

native species and all essential ecosystem processes.

The Applegate watershed contains a diversity of seral stages and stand structures.

Logging and especially fire exclusion have led to an abundance of younger, smaller

trees and increases in stand-structure complexity and canopy coverage. Habitats for

some native species have been promoted by fire suppression and bark beetle mortality,

which have increased stand-structure diversity and the numbers of snags across much

of the watershed. Other species that require fire have probably been adversely affected. Open savannas of pine (Pinus spp.) and oak (Quercus spp.) sustained by fire

have been lost. Heavy grazing and introduction of exotic plant species in some areas

have adversely affected rates and types of ecosystem processes and plant succession.

Based on this fourth criterion, the forests of the Applegate watershed are only marginally in a sustainable condition, and more data are needed to accurately assess the

current situation.

Having evaluated these criteria, what can be done to bring the Applegate watershed

into a sustainable condition? This evaluation permits managers to devise specific

approaches. Although the physical and biological resources and networks to support

productive forest are still in place, the watershed has lost resistance to catastrophic

change and the equlibrium between supply and demand of essential resources. A

strategy to reduce the potential catastrophic effects of fire and insects and address

major imbalances among the vegetative demands for water, nutrients, and growing

space will require a large, long-term, cooperative effort among ownerships. Because

the needs have been specifically identified, however, a measureable strategy can be

implemented.

The growing use of the terms “sustainable forests” and “sustainable forestry practices”

demands that natural resource users and managers understand the many different

perspectives embodied in them. Individual views of sustainability differ widely and

depend on various ecosystem perspectives, uses, and spatial and temporal scales. To

minimize conflict, confusion, and mistrust, sustainability needs to be defined. Clarity is

needed on what, where, for whom, and for how long forest values are being sustained

and assessed. Once specific definitions are in place, management objectives, activities, and monitoring measures can be implemented. One recommended approach is to

assess sustainability at the landscape level and define the processes, structures, and

resources needed to meet many of the objectives of society. In the Applegate watershed in southwest Oregon, this approach allows for specific needs to be identified and

strategies for sustainable forests to be implemented.

This research was supported by the Pacific Northwest Research Station Long-term

Ecosystem Productivity and People and Natural Resources Program. Many of the

concepts in this paper have emerged over the last few years out of the work and

thoughts of numerous people. Special thanks are due to Marty Main, David Perry, T.E.

Kolb, and Tom Atzet.

Conclusions

Acknowledgments
13

Amaranthus, Michael P.; Trappe, James M.; Perry, David A. 1993. Soil moisture,

native revegetation, and Pinus lambertianna seedling survival, growth and mycorrhiza formation following wildfire and grass seedling. Restoration Ecology. Sept.:

188-195.

Bisson, P.A.; Bilby, R.E.; Bryant, M.D. [and others]. 1987. Large woody debris in

forested streams in the Pacific Northwest: past, present, and future. In: Salo, E.O.;

Cundy, T.W. Streamside management: forestry and fishery interactions. Contrib. 57.

Seattle, WA: University of Washington, Institute of Forest Resources: 143-190

Bormann, F. H.; Likens, G. E. 1979. Pattern and process in a forested ecosystem.

New York: Springer-Verlag.

Bowyer, J.L. 1992. Realistic thinking and the North American approach to environmental issues: a dichotomy. Forest Products Journal. 42: 18-24

Dyck, W.J.; Mees, C.A., eds. 1990. Impact of intensive harvesting on forest site

productivity. FRI Bull. 159. Rotorua, New Zealand: Ministry of Forests.

Franklin, Jerry F.; Perry, David A.; Schowalter, Tim D. [and others]. 1989. Importance of ecological diversity in maintaining long-term site productivity of Pacific

Northwest forest ecosystems. Portland, OR: Timber Press.

Forest Ecosystem Management Assessment Team [FEMAT]. 1993. Forest ecosystem management: an ecological, economic, and social assessment. Portland, OR:

U.S. Department of Agriculture; U.S. Department of the Interior [and others]. [Irregular pagination].

Gosselink, J.G.; Shaffer, G.P.; Lee, L.C. [and others]. 1990. Landscape conservation

in a forested wetland watershed: can we manage cumulative impacts? Bioscience.

40: 588-600

Harmon, Mark E.; Franklin, Jerry F.; Swanson, Fred J. [and others]. 1986. Ecology

of coarse woody debris in temperate ecoysystems. Advanced Ecological Research.

15: 133-302

Koch, P. 1992. Wood versus nonwood materials in U.S. residential construction: some

energy related global implications. Forest Products Journal. 42: 31-42

Kolb, T.E.; Wagner, M.R.; Covington, W.W. 1994. Concepts of forest health. Journal

of Forestry. 92(7): 10-15

Magnuson, John J. 1990. Long-term ecological research and the invisible present.

Bioscience. 40(7): 495-501

Miller, Richard E.; Stein, William I.; Heninger, Ron L. [and others]. 1988. Maintaining and improving site productivity in the Douglas-fir region. In: Perry, D.A.;

Meurisse, R.; Thomas, B. [and others]. Maintaining the long-term productivity of

Pacific Northwest forest ecosystems. Portland, OR: Timber Press.

Monnig, E.; Byler, J. 1992. Forest health and ecological integrity in the northern

Rockies. FPM Rep. 92-7. [Place of publication unknown]: U.S. Department of

Agriculture, Forest Service.

Literature Cited
14

Perry, David A.; Meurisse, Robert; Thomas, Byron [and others]. 1989. Maintaining

the long-term productivity of Pacific Northwest forest ecosystems. Portland, OR:

Timber Press.

Powers, Robert; Van Cleve, K. 1991. Long-term ecological research in temperate and

boreal forest ecosystems. Agriculture Journal. 83: 11-24

Romm, J.; Washburn, C. 1987. Public subsidy and private forestry investment. Land

Economics. 63(2): 153-167

Sollins, Phil; Grier, C.C.; McCorison, F.M. [and others]. 1980. The internal element

cycles of an old-growth Douglas-fir ecosystem in western Oregon. Ecological Monographs. 50(3): 261-285

Species Analysis Team. 1994. Final supplemental environmental impact statement

on management of habitat for late-successional and old-growth forest related

species within the range of the northern spotted owl: appendix J2—results of

additional species analysis. [Place of publication unknown]: U.S. Department of

Agriculture, Forest Service; U.S. Department of the Interior, Bureau of Land Management. 417 p.

Thomas, Jack W.; Raphael, Martin G.; Anthony, R.G. [and others]. 1993. Viability

assessments and management considerations for species associated with latesuccessional and old-growth forests of the Pacific Northwest. Washington, DC: U.S.

Government Printing Office. 520 p.

Waring, Richard; Schlesinger, W.H. 1985. Forest ecosystems: concepts and management. [City unknown], FL: Academic Press.

World Commission on Environment and Development. 1987. Our common future.

Oxford, United Kingdom: Oxford University Press.
Amaranthus, Michael P. 1997. Forest sustainability: an approach to definition and

assessment. Gen. Tech. Rep. PNW-GTR-416. Portland OR: U.S. Department of

Agriculture, Forest Service, Pacific Northwest Research Station. 14 p.

Forest sustainability is a concept for the desired condition of forest ecosystems all

over the world. The essential aspects of sustainable forests differ tremendously,

however, among peoples of the world. Sustainability needs to be defined to minimize

conflict, confusion, and mistrust. For what, where, whom, and how long are forest

values being sustained? One recommended approach is to assess sustainability at

the landscape level and define the processes, structures and resources needed to

meet many of society’s objectives. A landscape-level example in the 200 000 hectare

Applegate watershed in southwest Oregon uses four criteria as a measure of

sustainability. With these criteria, management objectives, activities, and monitoring

measures can be implemented across the watershed. Managers and policymakers

must recognize that modern forest practices have a short history and there is little

documentation of long-term effects. Increased efforts are needed for well-designed,

long-term, and integrated approaches for monitoring forest sustainability.

Keywords: Applegate watershed, landscape level, forest management, social values,

spatial and temporal scales, sustainability.

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provide increasingly greater service to a growing Nation.

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