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Background, science issues,and research agendaPart Two of Two Parts

iven the wide range ofissues encompassed byconcerns over forest man-agement, a conceptualframework must be devel-

oped to identify the scopeof necessary research, to

layout key research objectives and ap-proaches, and to assign priorities to re-search tasks. An overarching frameworkis needed to provide a common language,frame and test hypotheses, and communi-cate the results. This framework must ac-commodate currently prominent issuesand must lead us forward-that is, make

productive sense of the results of science.A systems approach, which has a

broad and deep tradition in ecology andeconomics, helps clarify complex issuesand couches them in terms accessible to abroad scientific community (Watt 1966,Smith 1970, Shugart and O'Neill 1979,Boyce 1985). The systems approach isespecially appropriate to integrate thecontributions of many disciplines and fo-cus on common or compatible hypotheses.

Definition of TermsWe begin with the premise that a for-

est ecosystem can be described in termsof its states, stocks, and flows. A state de-scribes the condition with respect to cer-tain observable attributes measured at a

given moment. Key attributes are age,structure, and composition of vegetation;type, abundance, and distribution of wild-life; and type, magnitude, and distribu-tion of human benefits. Old-growth, forexample, is a forest condition defmed byan age-class of vegetation, structure offorest canopy I volume of dead and

downedwoody debris,and other at-tributes; old-growth is trees, other vege-tation (including decaying material),birds, mammals, and other organisms andthe manner in which they associate andinteract in communities. No single mea-sure, such as age, is sufficient to describeit (Franklin et aJ. 1981). Similarly, otherstates can be identified by condition andconsequent processes.

Old-growth is a state with tremendouspopular appeal; however, other states areequally important to forest ecosystemprocesses and to forest-dependent organ-isms. The limited nomenclature of statesreflects the fact that little attention has

been paid to describing or defining them.State descriptions depend on spatialscale; particular states may not be mean-ingful at all spatial scales, but all statesare scale-dependent. An old-growthstand, for example, will have a differentcollection of attributes than will an old-growth landscape. Although some statedefmitions are distinctive and somewhat

intuitive in their meaning (such as old-growth), others are less clear and for con-venience may be defmed as discrete con-ditions along a continuum. By defmition,each state is a distinct and unique collec-tion of attributes; however, one or moreattributes may have equivalent values inone or more states.

Ecosystems change states over time inresponse to both successional and distur-bance forces; disturbances include hu-man management as well as naturalevents such as fife, disease, and insects.Factors that develop slowly, such as at-mospheric pollution and climate change,are less obviously "disturbances" in the

.'

!

The first part of this article,

. pMblishtd in Jtl1UlIJry,aamined the

M:ientific. IfUUlagement,and social.focton tMt have contributed to the

~ lied for rethinkingsomebasic~ precqts of/orell management.Thist .UCOM part outlines aframework

for research and sllggests somedirections and approachts that must

be more fully tkveloped by scientists

from many disciplines.-Ed.

same sense, but are likely to affect bothsuccessional and disturbance processes.

One obvious model for this discussionis the successional stages of plant com-munities; in fact, a terminology and to-pology of states developed within ourcurrent understanding of forest succes-sion would provide the basis for examin-ing interactions among conditions,processes, spatial and temporal scales,and disciplines. The essential differencefrom traditional modeling (e.g., Shuganand West 1980) is that humans are in-cluded as an integral pan of the system.

A given state suppons various stocksand flows. Stocks are quantities of re-sources per unit area (e.g., number or vol-ume of standing trees, density of spottedowls or pine martens, miles of trail).Stocks are likely to be among the at-tributes useful in defming a system' sstate. Flows are the periodic yields fromthe stock of the system (water or sedi-ment discharge, annual production of fi-ber, annual smolt escapement. forest-dependent jobs). Stocks can be viewed asthe "capital" of the system (Costanza etal. 1991, EI Serafy 1991), flows the in-come produced by this capital.

Organization and FocusForest science has historically devel-

oped tools and methods for manipulatingstocks and flows without much attentionto states. This emphasis reflects society' s

. ,

FEBRUARY 1992 21

/RtSelU'Ch is lUeded 011 how GIld why speciJie ecosystems GIld IluuIsCDpeS challge oller time.

general perception that forests are pri-marily sources of commodities for humanconsumption-tangible flows separablefrom the system and often characterizedin economic terms. Some of the most vis-

ible (and volatile) political issues in for-estry relate to reductions in stocks ordisruptions in flows; for example, the lossof individual species or economic dislo-cations resulting from reduced timberharvests. But a more appropriate focusfor many major forest issues-forestfragmentation, biological diversity, for-est health, long-term sustainability-isthe state of the ecosystem. A shift in per-spective, from concern with stocks andflows to concern with states and associ-

ated stocks and flows, may be a "scien-tific revolution" (Kuhn 1970).

Looking at effects on states, stocks,and flows provides a common referencepoint for analyzing past, present, and fu-ture practices. As an example, many ofour current silvicultural practices in-crease the certainty of future wood fiberproduction (flow) by reducing risk of re-generation failure or mortality from inter-specific competition. In doing so, we mayhave reduced biological, structural, orfunctional diversity-risks related to for-est state. On the other hand, proposednew forestry techniques-such as green-tree retention-may accept increasedrisks to cenain flows such as wood fiberproduction, or ptoduce states with higher

22 JOURNAL OF FORESTRY

susceptibility to catastrophic loss, whilereducing the risk ofreduction in long-term productivity or system complexity(state characteristics), or loss of spottedowls (stock).

States, stocks, and flows define thenature of the trade-offs associated with

various actions; scenario analysis orga-nizes this information and examines pos-sible future conditions. A scenario

describes hypothetical changes in statesover time, and thus illustrates transitionsbetween two states or transitions betweena state and several successive states. Therules and assumptions used to generatechanges in either conditions or processesmust be stated. To fully depict a scenario,analysts must specify the basis forchanges in climate, land use, or manage-ment practices and how the system re-sponds to those changes. A consistentanalytical framework-ideally, a formalmodel-provides the basis for interpret-ing the effects of assumed changes inthese factors. For example, alternate sce-narios could describe progressivechanges in forest landscape structure overseveral decades under either dispersedharvesting or aggregated harvesting.

A Research AgendaAfter states. stocks, and flows are de-

fined, then scenarios can be developed todescribe the essential features of possiblefuture conditions. This scientific ap-

proach has six broad objectives:(I) defme, characterize, and measure

different forest ecosystem states;(2) develop methods to analyze stocks

and flows associated with different eco-system states;

(3) evaluate social benefits, values,costs, and preferences associated withdifferent states, stocks, and flows;

(4) determine factors that influencetransitions between states;

(5) develop scenarios and analyze as-sociated changes in states, stocks, andflows; and

(6) propose methods of public panici-pation in defining objectives and in de-signing and implementing forestdemonstration and research areas.

Characterize states. Producing scien-tifically credible and workable defmi-tions of possible states is the flTstandfundamental step. Developing ways todefme, characterize, and measure differ-ent forest ecosystem states is one of theprincipal challenges facing the researchcommunity. Research must provide bothquantitative and qualitative descriptionsof alternative forest states~ither de-

signed or unintentional-at all relevantspatial scales. Characteristics should en-compass a broad range of biological.physical, and social (including eco-nomic) features.

Designed forest states are those devel-oped for one or more specific manage-ment objectives, such as diversity.productivity. resiliency, complexity, orold-growth. One such state might be the"desired future conditions" identified in

national forest plans. Unintentional statesmay result from natural disturbances,such as wind and flTe,interacting with ei-ther a natural or designed landscape.Given a description of possible futurestates, social and political processes candetermine which of them society prefers.

Research must identify the full rangeof states possible for specific ecosystemsand landscapes. For example, can all sitessuppon old-growth? Do disturbancesproduce distinct states or a continuum ofpossible states? What characteristics dis-tinguish plantation forests from naturalforests?

Stocks andfloK's. Continued societalinterest in the flow of products from for-est ecosystems requires knowledge aboutthe quantities and qualities of stocks andflows associated with different ecosys-

tem states. With this knowledge, the ef-fects of altemative forest states on keyflows (timber, water, sediment, target or

indicator wildlife species, C02' user-days)can be assessed. Both quantity and qual-ity characteristics must be addressed.

Scientists need accurate methods toevaluate and measure flows of ecologi-cally significant products, keeping inmind likely distinctions between ecologi-cal significance and market-based value.Possible approaches include retrospec-tive studies, process studies, field experi-ments, computer modeling, and large-scale landscape experiments.

Social science. What social benefits,values, and costs are associated with dif-ferent states, stocks, and flows? Studiesmust identify the range of societal bene-fits represented by different states. Oneobvious component is the direct eco-nomic benefits associated with specificstates or scenarios (for example, forestsmanaged primarily for timber, biodiver-sity, or spotted owls). However, econom-ics research must go beyond simplemeasures, such as the number of jobs andthe value of wages, to produce a compre-hensive view of the role of forest re-sources in economies and communities.We also must improve our ability to as-sess the economic arid social benefits offorest attributes other than timber.

In a more general sense, we also needto identify the values assigned by thepublic to different forest states and sce-narios. For example, what are the valuesattached to old-growth? To plantationforests? To a forest managed primarilyfor.diversity? To a fragmented forest?Important results may be more effectivecommunication among different groupsof forest users regarding their visions ofthe future forest and a clearer expressionof preferences.

Transitions between stales. Greater

understanding is needed concerning thefactors that influence transitions betweenstates-i.e., how natural and anthropo-genic processes (vegetation age, struc-ture, composition, pattern) change theforest attributes that define states.Changes may be due to succession, com-petition, and other autogenic processes orin response to environmental conditionssuch as fire, wind, and climate change.Such research will evaluate probabilitiesand paths for transitions between statesand for scenarios, and elucidate mecha-

nisms of ecosystem change. This workcan be viewed as defining the "topology"of states: the domain of possible states forparticular ecosystems.

Scenarios. An integrated and interdis-ciplinary analysis of forest stand andlandscape change is a fifth area for re-search. Scientists must describe ecosys-tem change through time and analyzechanges in states, stocks, and flows, andbenefits associated with each of them.After scenarios are defmed, alternativefuture states can compare, for example,even-aged and uneven-aged managementat the stand scale, or aggregated and dis-persed cutting patterns at the landscape .

scale. A major emphasis will be to por-tray the effects of alternative mecha-nisms, patterns, or rates of vegetativechange over time and at a variety of spa-tial scales. This effon could expand com-munication among researchers,strengthen research planning, and formu-late alternative hypotheses of future for-est conditions.

After scenarios are defmed, individualdisciplines must analyze effects of the al-ternative scenarios on stocks and flows ofinterest (e.g., marketable commodities,stream flow, or specific wildlife species).This process is iterative in the sense thatthe results from the first round would log-

ically lead to develop-ment of additional

scenarios.

Public participa-tion. Finally, re-searchers should

develop new methods to involve the pub-lic in defining objectives for forest man-agement, and in designing andimplementing effons to demonstrate andexamine the consequences of these objec-tives. The public plays a critical role.inevaluating and choosing among alterna-tive future states; new approaches to ex-pand public involvement should includeexperiments in both forest management(effects on forest ecosystems) and the ef-fectiveness of public participation. Thisapproach, which represents a new oppor-tunity, may playa key role in producing apublicly acceptable-and technicallyfeasible-vision of future forests.

Demonstration areas can be part of.traditional. controlled experiments. andpart of a broadened experimental design(in which strict controls are not possible)to evaluate new forestry practices. Ad-justments in future management strate-gies-adaptive management (Walters1986)-can be based on these experi-ences with ecosystems and human expec-tations. Demonstration areas offer a vital

meeting ground for researchers. manag-ers, and the public, and a medium fortransfer of research results into practice.

ConclusionsThis research agenda will require

many years, and process, retrospective.modeling, and field experiment studiesmust occur simultaneously. Becauselarge-scale experiments and data collec-tion take many years to complete. theseactivities require early attention and in-

Old-growth is a statewith tremendouspopular appeal;however, other statesare equally importantto forest ecosystemprocesses and to forest-dependent organisms

FEBRUARY 1992 23

vestment. Meanwhile, scientists mustdemonstrate an ability to contribute tonear-term management and policy deci-sions. Such participation is risky, as sci-entists will increasingly be drawn intoconflicts over resource use that are basedon conflicts in values. Under these condi-

tions, evaluating information and makingdecisions become increasingly difficultfor policy-makers and the public; to con-tribute effectively, scientists must main-tain scientific credibility.

Early efforts should concentrate onretrospective studies-analyzing forestpattern changes through time, identifyingecological responses to alternative silvi-cultural treatments, comparing historicalstream flow data with patterns of harvest,and compiling and analyzing economicand social benefits at various spatialscales.

New scientific issues in forest man-

agement include the wide range of scales

24 JOURNAL OF FORESTRY

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at which questions are being raised; amore systematic view of forests; broaderobjectives and concerns for forested eco-systems; and improved public participa-tion in setting a research agenda. Thedifference from previous forest manage-ment science is the attention to issues atlarger spatial scales and explicit recogni-tion of the need for interdisciplinary ap-proaches. Only by considering groups ofstands (landscapes, multilandscapes, andregions) can biological diversity, habitatand hydrological impact, and interactionwith human communities be addressed.

Although this research agenda incor-porates some new approaches to forestmanagement and forest research, it isdeeply rooted in the past 50 years of for-est science. Shifting social values, an ex-panded understanding of ecosystemdynamics, emerging technologies, and aripe political and social climate allow usto reevaluate basic assumptions about the

role of forests in society. These new ap-proaches reflect a growing recognition ofthe need to view forests as integrated ec-osystems operating within a range of tol-erance, rather than as limitless producersof commodities for human consumption.Research cannot define social objectivesfor forests, but it can help evaluate theecological, social, and economic trade-offs between alternative visions. 8

Literature CitedBOYCE,S.G. 1985. Forestry decisions. USDA

For. Servo Gen. Tech. Rep. SE-35. 318 p.COSTANZA, R., H. DALY. and J. BARTIlOJ.O.

MEW. 1991.Goals,agenda,andpolicyrec-ommendations for ecological economics.P. 1-20 in Ecological economics: the sci-ence and management of sustainability, R.Costanza, ed. Columbia Univ. Press, NewYork.

EL SERAf'Y. S. 1991. The environment as cap-ital. P. 168-75 in Ecological economics:the science and management of sustain-ability. R.Costanza, ed. Columbia Univ.Press, New York.

FltANKLIN,J.F., et aI. 1981. Ecological charac-teristics of old-growth Douglas-fu forests.USDA For. ServoGen. Tech. Rep. PNW.118.

KuHN,T. 1970. The structure of scientific rev-

olutions. Ed. 2. Univ. Chicago Press. Chi-cago. 210 p.

SHUGART,H.H., and R.V. O'NEn.L, eds. 1979.Systems ecology. Benchmark Pap. in Etol.9. Dowden. Hutchinsen, & Ross, Inc.,Stroudsburg, PA. 368 p.

SHUGART.H.H., and D.C. WEST.1980. Forestsuccession models. BioScience 30:308-13.

SMITH,F.E. 1970. Analysis of ecosystems. P.7-18 in Analysis of temperate forest eco-systems, D.E. Reichele. ed. Springer- Ver-lag, New York.

WAL'JERS,C. 1986. Adaptive management ofrenewable resources. Macmillan Pub!..

New York. 374 p.WATT.K.E.F., ed. 1966. Systems analysis in

ecology. Academic Press. New York..276p.

David J. Brooks is research forester and Gor-

don E. Grant is research hydrologist, USDAForest Service. Pacific Northwest ResearchStation,Corvallis.OR.

AcknowledgmentsThe authors wish to acknowledge contribu-tions from Martha H. Brookes, Susan S.Hanna, Richard W. Haynes, Martin G.Raph-ael, Gordon H. Reeves, Thomas A. Spies, andFrederick J. Swanson.

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