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Conservation Biology, Pages 930–932Volume 12, No. 4, August 1998

A Biologist’s Perspective on the Role of Sustainable Harvest in Conservation

THOMAS T. STRUHSAKER

Department of Biological Anthropology and Anatomy, Duke University, Box 90383, Durham, NC 27708–0383, U.S.A.,email tomstruh@acpub.duke.edu

“Sustainable harvest” is one of the most commonly mis-understood and misused concepts in today’s conserva-tion arena. It generally refers to activities that involvethe extraction of a natural resource in such a mannerthat it is not depleted and can renew itself so that similarlevels of exploitation can occur indefinitely. I addressseveral of the more important misconceptions surround-ing the idea that sustainable harvest is an important strat-egy for conservation and offer an explanation as to whythe concept is currently so popular.

Unfortunately, the concept of sustainable harvest hastoo often been equated with effective conservation. Tothe contrary, sustainable harvest is invariably an activitywhose objective is the material welfare of a select groupof humans. Sustainable harvest does not necessarily haveanything to do with conservation of species except in acoincidental and passive way. Rarely is considerationgiven to the impact of so-called sustainable harvests onother, nonmarketable species that are part of the ecosys-tem being exploited.

Four years ago Robinson (1993) provided an excellentcritique of the concept of sustainable development andshowed how it is generally incompatible with the goalsof conservation. In spite of this and other forceful argu-ments and case studies showing how sustainable devel-opment projects can be counterproductive to conserva-tion (e.g., Wells & Brandon 1992; Brandon 1997; Krameret al. 1997; Noss 1997; Oates 1995, 1997), the sustain-able development movement as a purported conserva-tion strategy is gaining in popularity and is being fundedat higher levels than ever before.

In the case of tropical forests, the sustainable harvestof timber has been given recent attention in semi-popu-lar articles (McRae 1997; Rice et al. 1997), overviews byforesters and plant ecologists (Dickinson et al. 1996), scien-tific tomes (Struhsaker 1997), and policy perspectivesby international development agencies (Canadian Inter-national Development Agency, Forestry Advisors Net-

work, http://www.cfanrcfa.org). One clear message fromthese publications is that the relevance of sustainable har-vest to conservation remains very much open to ques-tion. My objective is to highlight some of the key issuesthat must be considered if future attempts at sustainableharvest are to make a meaningful contribution to theconservation of old-growth or mature ecosystems.

First, are any harvests of natural resources sustainable?Long-term and critical evaluations of attempts at sustain-able harvest are painfully scarce and generally do notsupport the concept. That most, if not all, attempts atsustainable harvest have failed, whether they concernmarine fisheries (Larkin 1977; Ludwig et al. 1993) or trop-ical timber (Struhsaker 1997), does not deter advocates ofintegrated conservation and development projects (ICDPs)and of the “conservation-through-use” (“use it or lose it”)perspective from continuing to invoke the concept in thename of successful conservation.

The second issue concerns what is perhaps the great-est criticism of the sustainable harvest concept, that itrepresents a narrow perspective. Sustainable harvest isgenerally thought of in reference to a relatively smallproportion of all the species living within the ecologicalcommunity being exploited (Robinson 1993). For exam-ple, discussions of sustainable harvest of timber in thetropics rarely consider anything but the tree species be-ing harvested (e.g., Dickinson et al. 1996; but for excep-tions see Rice et al. 1997; Struhsaker 1997).

In fact, timber-production forests are usually not com-patible with sustainable conservation of the other non-harvested species, plant or animal, that depend on old-growth forest. Harvest systems can be developed thatyield tropical timber over at least two or three cuts, butthese systems have never been shown to conserve thefull complement of old-growth species (Struhsaker 1997).These intensively managed forests more closely resem-ble tree plantations than natural forests. They are oftenimpoverished in terms of plant and animal species (Struh-

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saker 1997). The flora and fauna that follow heavy log-ging are usually dominated by colonizing (weed) speciesand not those adapted to old-growth forest (Struhsaker1997). Peter Ashton is quoted as saying: “Let’s not pre-tend that sustained-yield forestry and biodiversity preser-vation are in any way compatible” (McRae 1997).

Because the concept of sustainable harvest, as it isgenerally used, is not readily demonstrable and, there-fore, of limited value in developing conservation man-agement plans, a third important issue must be ad-dressed. When harvest systems of natural resources aredeveloped, a reference point or perspective must be es-tablished and all of its consequences carefully consid-ered. If one’s objective is to produce only timber, thenstudies and management plans need be concerned onlywith those species relevant to the regeneration, growth,and reproduction of the timber species being exploited.If one’s objective is the sustainable conservation of old-growth species, on the other hand, then it is this com-munity of species that must be evaluated and studied,not just the timber species being logged, because anyform of extraction has an impact.

The fourth point, and an important caveat with regardto the implementation of sustainable harvests in the con-ventional sense, is that as market demands increase,whether due to increasing human populations or in-creasing levels of consumption per capita, the tempta-tion is to increase harvest levels accordingly (Struhsaker1997). What was considered a sustainable (i.e., suffi-cient) harvest 5–10 years ago will likely be inadequatefor contemporary and future market demands. In re-sponse to escalating economic, social, and political pres-sures, sustainability is redefined and harvest levels in-creased accordingly (Larkin 1977; Ludwig et al. 1993).This is particularly so for tropical countries where hu-man populations are increasing at 3–4% per year. But italso occurs in wealthy, temperate-climate countries thathave relatively low rates of population growth, such asthe United States and Canada.

Given the preceding points, we must ask a final ques-tion. Why is the concept of sustainable harvest as a con-servation strategy so widely advocated? Too often thesuccess of integrated conservation and developmentprojects or other sustainable harvest projects is equatedwith the project’s fund-raising capabilities because man-agement policy and practice are usually influenced inproportion to the availability of funds. Correspondingly,these project designs tend to be shaped and driven bythe donors and, because the wealthiest donors comefrom the development industry (e.g., World Bank, U.S.Agency for International Development, Overseas Devel-opment Agency [U.K.], European Community, Norwe-gian Agency for Development, Swedish InternationalDevelopment Agency, Japan International CooperationAgency, Overseas Economic Cooperation Fund [Japan]),they assume a development perspective. In other words,

the paradigm of conservation through development, in-cluding the sustainable harvest concept, originated withindividuals and organizations primarily concerned withhuman welfare and economic growth (an anthropocen-tric perspective) and not with biological conservation (aholistic perspective). Based on 35 years of experiencewith tropical conservation, I believe one of the main rea-sons the concept of sustainable harvest has gained pre-eminence in today’s conservation arena is not because ithas a well-established history of success but because de-velopment agencies have far more money to offer thando conservation organizations that advocate a more tra-ditional and holistic approach. In other words, funding,rather than conservation, has become the predominantobjective of the implementing organizations.

An additional force that encourages and fosters the“development” approach to conservaton is the rapidlygrowing human population in the tropics. Because rap-idly growing or high-density human populations usuallyrepresent the most serious threat to old-growth forestsin the tropics (Bruenig 1989; Struhsaker 1997), as wellas other ecological communities, they must be dealtwith in some way. Rather than address the ultimate andunderlying issue of population control and planning, thedevelopment approach encourages plans based on sim-plistic and/or inappropriate concepts of economic growthand sustainable harvest (Robinson 1993). Combined withthe population problem is an increasing concern for in-digenous peoples (Kramer & van Schaik 1997), whichfurther encourages the development approach to con-servation.

Sustainable harvest is offered by its proponents as aconcept that resolves conflicts between conservationistsand exploiters through compromise. The trend and thevery real risk are that, unless dealt with in a far moreobjective and holistic—less anthropocentric—manner,the current patterns of sustainable harvest will continueto drive old-growth species and ecosystems to extinc-tion. In terms of effective conservation of old-growthspecies, there is no substitute for totally protected areas.Realizing that not all remaining old-growth habitats willbe given total protection, buffer zones and other formsof extractive reserves can play important roles in conser-vation. They are, after all, better options than completeconversion to monocultures. These extractive areas will,however, play a significant role in conservation only ifharvest levels are established with the goal of conserv-ing all members of the old-growth community and notjust the commodity being harvested.

Acknowledgments

I thank the following individuals for helpful commentson the manuscript: T. M. Butynski, D. Forthman, G. K.Meffe, J. F. Oates, and T. P. Young.

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