Sayer, Jeffrey A.

Stuart, Simon

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GUEST COMMENTBiological Diversity and Tropical ForestsThe conservation of biological diversity has recently become a subject of significant international action.Task-forces in its support have been established by institutions such as the World Bank, and campaignsto improve its prospects are being orchestrated by international nongovernmental conservation organi-zations. This world-wide concern is largely based on the widespread belief that more species of organisms arebecoming extinct in the latter part of the 20th century than at any time in the history of the Earth. A majormanifestation of this concern is the significant international effort which is now under way to save the forestsof the tropical 'developing world'. These forests are the most biologically diverse biomes on Earth, and manyof the present species extinctions are thought to result from their rapid disappearance.The current preoccupation with the conservation of biological diversity leads to a tendency to concentrateconservation efforts in areas where this diversity is greatest. The term 'megadiversity' has been applied inrespect of such areas as the Atlantic forests of Brazil, the east-coast forests of Madagascar, PeninsularMalaysia, and parts of the huge island of Borneo. These sites are indeed of very high value for conservation,and consequently merit special international attention. However, a logical extension to this preoccupationwith species diversity as a criterion for the application of conservation resources, could lead to unfortunatedistortions of conservation programmes, much as can overemphasis on conservation of a single species.IUCN's Ongoing ProgrammeThe 'World Conservation Union', IUCN (the International Union for Conservation of Nature and NaturalResources), has ongoing programmes which monitor the status of species and protected areas throughout theworld. Recent analyses of data from various components of this programme have shown that existing systemsof protected areas, at least in the old-world tropics, contain a remarkably high proportion of the biologicaldiversity of those groups of plants and animals for which information is available. For instance, in 12 Africancountries that were studied, between 47% and 91% of their native bird species are present in protected areas,and in most cases population sizes are thought to be viable for long-term conservation (Table I and see Sayer,McNeely & Stuart, 1988). Moreover, several of the species which are not present in protected areas are coastalor marine species, or are associated with human settlements and agricultural land. These species are probablynot particularly endangered. A relatively small number of additional sites are known in Africa whoseprotection would lead to a situation where virtually all African bird species would receive a reasonable level ofprotection in national parks and reserves.Recent studies by P. Round (cited in IUCN, 1986) in Thailand have shown that 508 of the 578 species ofresident birds occur in the existing system of National Parks and Wildlife Sanctuaries. Of the remaining 70species, 27 are open-country species which are unlikely to be severely threatened by forest loss, while 10 of theother species are considered likely to occur in protected areas but have not yet been confirmed as doing so. Avery high proportion of the mammals of India are thought to be adequately conserved in the 30 areas thatwere established some years ago under 'Project Tiger' as Tiger (Felis tigris) reserves. The situation with plantsis much less clear, and information currently available is quite inadequate to permit any generalizations.Diverse Floras Under Threat?There is certainly evidence that, in some parts of the Andes and the Andean foothills of the Amazon basin,areas of very diverse flora are under great threat from transformation to agriculture, while the species whichthey contain are very inadequately represented in protected areas. However, for some sites in the forests of theold-world tropics for which information is available, the situation may not be as bad as one might fear. Over50% of the endemic vascular plants and 64% of the trees of Sri Lanka are known to occur in the 11,000-haSinharaja Biosphere Reserve in the moist lowlands of the south-west of the island (Gunatilleke & Gunatilleke,1985). Anderson et al. (1982) have listed 450 pteridophytes and 1,500 angiosperms from the Mulu NationalPark in Sarawak, representing about 20% of the vascular plants that are currently known from the entireisland of Borneo. The 4,500 species of vascular plants that are estimated to occur in the Mt Kinabalu NationalPark in Sabah represent 45% of the known vascular flora of Borneo (Cockburn, 1978; Corner, 1978).The conclusion which we draw from these figures is that, if the preservation of species is our primaryconservation objective, then we might best achieve this through investing in completing, and assuringadequate management of, the network of national parks and reserves in the tropical forest biome. At presentsome 9.7% of the remaining moist forests of Africa are protected in national parks and equivalent reserves. Itis probable that as many as 90% of all tropical forest vertebrates species of that continent would be maintainedif these and a few additional critical sites could be adequately protected.193Environmental Conservation, Vol. 15, No. 3, Autumn 1988—©1988 The Foundation for Environmental Conservation—Printed in Switzerland.https:/www.cambridge.org/core/terms. https://doi.org/10.1017/S0376892900029295Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 13:30:41, subject to the Cambridge Core terms of use, available at194 Environmental ConservationTABLE INumbers of Species of Birds Occurring in Protected Areas in Selected African Countries.CountryNumber ofbird species inprotected areasNumber ofbird species inthe countryPercentagein protectedareasLiterature source *CameroonGhanaIvory CoastKenyaMalawiNigeriaSomaliaTanzaniaUgandaZaireZambiaZimbabwe64955856890848571930283388096763758184872168310646248316391 016989108672863576.577.483.285.377.786.547.382.089.089.087.591.5Louette (1981)Grimes (1987)Thiollay (1985)Britton (1980)Benson & Benson (1977)Elgood (1982)Ash & Miskell (1983)Britton (1980)Britton (1980)Lippens & Wille (1976)Benson et al. (1970)Irwin (1981)* Not cited in References but available from the Authors. — Ed.Increase Reserves to Protect SpeciesIt might be possible to ensure the continued existence of a high proportion of the plant and animal species ofthe planet through a relatively modest increase in resources applied to existing protected area programmesespecially in the moist tropics. However, in adopting such a strategy, we would need to be aware of the factthat conservation resources might thus be diverted away from measures to conserve functioning ecosystemsthroughout the ecobiome. To take an extreme example, the emphasis on biological diversity conservationwould suggest that very few conservation resources should be applied to the species or ecosystems of theSahelian zone. But one could argue that the continued functioning of these fragile ecosystems might in realitybe a much higher conservation priority than the preservation of the very highly diverse fauna of folivorousColeoptera in the tropical forest canopy. Similar arguments could be applied to polar, mountain, wetland, ormarine, ecosystems where small numbers of species have critical ecological roles in maintaining ecosystemfunctions.At a period when the prospects of global climatic change make all predictions of the future evolution of TheBiosphere somewhat problematical, it would seem unwise to base one's conservation strategy on an excessiveconcentration of resources in a small number of megadiversity sites. Instead, we would contend that thebalanced approach to conservation prescribed by the World Conservation Strategy remains the mostappropriate standard by which to dispense those resources which are available for conservation. Biologicaldiversity is just one, admittedly important, criterion alongside the need to conserve ecosystem functions andto promote sustainability in the exploitation of all biological resources.REFERENCESANDERSON, J.A.R., JERMY, A.C. & CRANBROOK, Earl of (1982). GunungMulu National Park: A Management and Development Plan.IUCN/WWF Project 1576, Royal Geographical Society, Kensington Gore, London SW1, England, UK: 345 pp., illustr.COCKBURN, P.F. (1978). Flora. Pp. 255-63 in Sabah Society Monograph [not available for checking].CORNER, E.J.H. (1978). Plant life. Pp. 113-78 in Sabah Society Monograph [not available for checking].GUNATILLEKE, C.V.S. & GUNATILLEKE, I.A.U.N. (1985). Phytosociology of Sinharaja—a contribution to rain forest conservation in SriLanka. Biological Conservation, 31, pp. 21-40.IUCN (1986). Review of the Protected Areas ofthelndo-Malayan Realm. IUCN and UNEP, Gland, Switzerland & Cambridge, England,UK: 284 pp. + maps.SAYER, J.A., MCNEELY, J.A. & STUART, S. (1988). Enhancing the Contribution of Conservation Biology & Conservation Practice: APerspective from the Old-world Tropics. Paper presented to the Second Annual Conference of the Society for Conservation Biology,Davis, California, USA: 17 pp., mimeogr.JEFFREY A. SAYER, Senior Programme AdviserTropical Forest ConservationIUCN/UICNAvenue du Mont-Blanc1196 Gland, Switzerland,& SIMON STUART, Species Programme OfficerIUCN/UICNAvenue du Mont-Blanc1196 Gland, Switzerland.https:/www.cambridge.org/core/terms. https://doi.org/10.1017/S0376892900029295Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 13:30:41, subject to the Cambridge Core terms of use, available at

Biological Diversity and Tropical Forests

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