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Conservation and protection of tropical rain forests: The perspective of the World Conservation Union

J. Sayer

Jeffrey Sayer is Coordinator of the Tropical Forest Programme of the World Conservation Union (IUCN). He is based in Gland, Switzerland.

The majority of the world's biological diversity is to be found in the moist tropical forests

The urgency of conserving the remaining tropical moist forests has attracted enormous attention in the media and in political environments in recent years. But among foresters, naturalists and natural resource managers this concern is not new. In 1948, at the meeting in Brünnen, Switzerland, where the decision was taken to establish the International Union for the Conservation of Nature and Natural Resources (IUCN) now the World Conservation Union - tropical rain forests were identified as an important target for attention. Even much longer ago, concern was already being expressed. For example, in 1850 the British Association for the Advancement of Science appointed a committee to consider "the probable effects, from an economical and physical point of view, of the destruction of tropical forests". A report by the committee mentioned the economic value of teak for export although considerable attention was also given to the ill-effects of felling trees on steep slopes.

Early concern centred upon the environmental values of tropical forests. Recognizing that the removal of forests disrupted hydrological functions and microclimates, the objective of foresters and land managers was to ensure the maintenance of some form of forest cover. However, it was thought that any type of forest could protect soils and watersheds and it was not considered particularly important to maintain the forest in a natural state.

In the late nineteenth and early twentieth centuries, as resource management legislation and forest departments were gradually set up throughout the tropics, the main emphasis was on defining and protecting a "permanent forest estate". At this point, the objective was to maintain forest cover on environmentally sensitive areas and to ensure supplies of forest products. In most tropical countries, "forest reserves" were established in which the extraction of timber and non-wood products was allowed on condition that a permanent forest cover was maintained.

The biological richness of rain forests, at least in terms of the more conspicuous plants and animals, was recognized by nineteenth-century botanists and zoologists who visited the tropics. Charles Darwin commented that: "Delight... is a weak term to express the feelings of a naturalist who for the first time has wandered by himself in a Brazilian forest."

Alfred Russel Wallace collected 700 species of butterflies and moths within an hour's walk of his house in eastern Amazonia, one in 30 of all the world's known species. However, very little was known of the distribution of even these species within the forests, and even less of their ecology or habitat requirements. The amazing diversity of less conspicuous arthropods and the soil fauna and flora were almost completely unknown.

Thus, in the first half of the twentieth century, while many tropical countries were establishing national parks and reserves to protect outstanding landscapes or conspicuous species of large mammals and birds (tigers in Asia, game in the plains of Africa, etc.), very little attention was given to the protection of the rain forests and their flora and fauna.

With hindsight this is easy to understand. Until the 1950s there were vast areas of tropical rain forest which had suffered very little disturbance. Clearance had occurred on the fringe of the true rain-forest zones in Madagascar and mainland South and Southeast Asia, and in areas where alluvial or volcanic deposits provided especially rich soils suited to agriculture. But the major forest blocks of Amazonia, central Africa and insular Southeast Asia were largely intact.

The situation then began to change radically. Technological advances occurring around the time of the Second World War resulted in heavy tracked vehicles becoming widely available. It was suddenly feasible to build access roads into remote forest areas. The wide availability of mobile power handsaws greatly facilitated clearing and logging in remote forest areas, and the transport of large-size timber became much easier. Stable, strong and aesthetically attractive tropical timbers were in increasing demand in distant industrial markets as a result of industrial growth. Equivalent timbers from temperate sources were in short supply and were also expensive as investments in forest management in the North created a significant price differential.

The sudden availability of modern medicines, health care and food in tropical countries triggered a doubling of human populations between 1950 and 1990. Most of this growth occurred in the tropics or subtropics. Population growth generated greatly increased demand for resources and also a vast reservoir of poor people eagerly seeking new lands on which to eke out a living. The new access roads into the forests were an irresistible magnet to these people.

Forest departments and nature conservation bodies found themselves unprepared for the dramatic increase in on tropical forest resources. Legislation, enacted in days when pressures were fewer, proved inadequate, inappropriate and unenforceable in the changed circumstances. Powerful industrial logging interests found it easy to circumvent or ignore forest management plans, and burgeoning rural populations living at the brink of subsistence could not be denied access to the only unoccupied lands available. The period from 1950 to 1990 saw unprecedented degradation, clearance and fragmentation of the world's rain forests.

Gunung Leuser National Park in Indonesia is of great importance for biological diversity and also as a reliable source of water for downstream agriculture pressure

Light disturbance is important in contributing to fatal diversity of the forest (for example, tree ferns are typical of species that colonize forest gaps and edges)

The biological value of rain forests

The period from 1950 to 1990 al so saw an unprecedented increase in the level of scientific interest in tropical forest ecosystems. New universities and research institutes sprang up in tropical countries and affordable air travel allowed researchers from the industrialized world to conduct field work in the tropics. The communication of research findings through initiatives such as the Unesco International Biological Programme in the 1960s and, later, the Man and the Biosphere Programme, led to greatly increased awareness of the enormous wealth of species in tropical forests.

In the light of classic studies by Erwin (1988) on the insect fauna of the canopies of trees in Central America, scientists upwardly revised their estimates of total species diversity by several orders of magnitude. Some 1.4 million species of organisms have been described by science to date, but extrapolation of the work of Erwin and others suggests that the total number of species in the world may be as many as 20 to 80 million (Stork, 1988). The vast majority of these are inhabitants of the tropical forest canopy.

Although the higher plants and vertebrates of tropical forests are now reasonably well-catalogued, new species in these groups are still being described with surprising frequency. Even among the primates, several new species were described in the 1980s, and all plant collections from the humid tropics contain a significant proportion of undescribed species.

Parallel to this emerging realization of the amazing diversity of tropical forests is an increasing awareness of the complex interdependence of many species. Terborgh, working in the Peruvian Amazon, coined the term "keystone species" for those trees whose selective elimination could provoke the domino-like extinction of many animal species that depended on them for their food and habitat. Other studies have shown that there are animal species which play a similarly vital role in completing the life cycles of rain forest plants of considerable economic importance. The euglossine bees, essential for the pollination of Brazil nuts in the Amazon, are an often-cited example (Goodland and Ledec, 1988).

Studies on the genetics of small populations of organisms have also changed perspectives regarding the problems encountered in the conservation of tropical forest species. Many predictions of species extinction in tropical forests have been based upon a formula, derived from observations on islands, that a 90 percent reduction in habitat size will result in a 50 percent loss of species. However, it is now clear that the distribution, size, location and interconnectedness of forest areas are all important factors in determining species survival. It appears that the fragmentation of forests into small, isolated reserves may reduce populations of widely dispersed species to levels that are not viable in the long term. Thus, although some publications may have exaggerated the number of endangered species, we may have underestimated the number that have been reduced to levels where they are already condemned to eventual extinction. The majority of the higher plants, birds and mammals of tropical forests are present in national parks and reserves, but many constitute such small populations that they may already be condemned to extinction as a consequence of genetic deterioration or random climatic or human-induced events.

The challenge of forest conservation

There is broad consensus among conservationists that forest management, beyond ensuring wood supplies and protecting watersheds, should also maintain the maximum number possible of plant and animal species (Poore and Sayer, 1987). This is based on the realization that many species have actual or potential values for human beings. Some highly improbable species have produced medicinal drugs or have proved to be vital in the genetic improvements of crops, in pest control, or in ecological functions. There is no doubt that many more will prove to have great value for humans, either directly or indirectly. There is also wide acceptance that even those species that make no apparent contribution to the material well-being of people should be conserved. This recognition is embodied in the World Conservation Strategy and has been recognized by the United Nations General Assembly through the adoption of the World Charter for Nature and the endorsement of the report of the World Commission on Environment and Development (WCED, 1987). Given the imperative of conserving all species, FAO, UNEP and IUCN are now collaborating in the preparation of an international convention for the conservation of biological diversity.

The safest way of ensuring the maximum protection of these species is to allocate significant forest areas to national parks and reserves where human interference is minimized. Protected areas covering tropical savannah, mountains and wetlands were largely in place by the 1960s, but it was only from 1970 onward that priority was given to according tropical moist forest habitats protection, a consequence of our greater appreciation of the value of their biological diversity and of the threats of deforestation.

There was a major move to gazette protected areas in the 1970s and 1980s (see Figure 1), and the latest United Nations list of protected areas (IUCN, 1980) includes 669 sites in the lowland tropical moist forest biome, covering some 66 million ha (see Table). They are areas lying within the limits of this biome, as determined by Udvardy (1984), and falling within IUCN categories l-IV of protected areas of which no significant human use is permitted. Not all of these protected areas are entirely forested and probably only about 5 percent of the biome is under this form of total protection.

A legal gazette alone does not guarantee protection. As long as poverty exists in the tropics, people with limited resources will turn to the forests to supplement their food supplies and incomes. Human greed is also a factor. There will always be individuals who strive to enrich themselves even at the expense of society at large. Valuable stands of timber in national parks can be threatened by urban elites, who dominate the timber industry and have the power to influence legislation, as much as by poor rural people.

Even if the conservation status of these 669 areas could be assured, our knowledge of forest ecology and biogeography tells us that they would be inadequate to prevent the extinction of large numbers of animal and plant species. Therefore, more totally protected parks and reserves are urgently needed but, as is evident from Figure 2, fewer are being established now than in the past. Present trends suggest that achieving even the modest target of 10 percent total protection of all the tropical moist forest remaining in 1990 will be very difficult. This is a reflection of the fact that pressures on land are increasing and fewer options for new protected areas are available. A major priority for the conservation community, therefore, must be to identity additional sites that are of special significance for biological diversity, and bring them under management for conservation.

Crops gathered for market from natural forests can enhance the value of these forests for local people

However, protection of even large areas of the tropical rain forests would not in itself guarantee maximum biodiversity. In completely undisturbed areas, natural evolution continues; although most species remain, many are naturally replaced by others. Therefore, the conservation of desirable species requires deliberate management.

Furthermore, many forest species are remarkably resistant to the periodic disturbance of their habitat (Johns, 1985). Indeed, the periodic fragmentation of forests during periods of climatic change and the diversification caused by storm damage, and even by traditional cycles of shifting cultivation, have all contributed to the rich diversity of today's forests. Many species have adapted to the regeneration of forest areas after disturbances and would be less abundant if all human interferences were to cease. The four species of wild cattle in Southeast Asia are a notable example (Wharton, 1968). Another is the natural emergence of vigorous pioneering tree species which form a new, dense forest stand after clear-felling.

Therefore, the challenge for the conservation community is not only to protect larger areas of tropical rain forest, but to ensure land uses outside protected areas that will enhance and complement the conservation value of parks and reserves, while providing sustainable socio-economic benefits.

Conserving biological diversity in managed forests

With the knowledge that human needs for land and raw materials will result in the modification of most of the forest outside protected areas, as well as the permanent conversion of a significant portion to other uses, we need to assess the various options that exist for the use of these forests and the land on which they grow, and also determine which will yield the greatest benefits for the conservation of biological diversity. Empirically, diverse forest systems composed of native species in an arrangement similar to the natural forest of the site would seem the most likely to support the maximum number of original plant and animal species.

Ecological coverage of protected areas of moist tropical forests


No. of areas

Total area (ha)



9 448 837



18 314 029



8 150 053



30 130 486



66 043 405

FIGURE 1. Cumulative growth of the world coverage of protected areas in tropical forest regions

FIGURE 2. Growth of the world coverage of protected areas in tropical forest regions over five-year periods

Note. The figures refer to 610 protected areas in moist tropical forest and mixed insular systems up to 1985. Additional sites were designated in the period 1985-1989 and a further 80 protected areas (totalling 81 000 ha and consisting mainly of mangrove ecosystems) have been designated over the past ten years on the islands of Andaman and Nicobar. However, both the number and size of new protected sites are declining.

The best land uses will therefore be the harvesting of non-wood products from the natural forest, and selective logging systems where a small number of high-value timber trees are extracted without gross disruption to the remaining vegetation.

Many of the challenges related to the achievement of adequate management standards for ensuring sustainability and preventing the loss of biological values are economic or political, rather than technical. Much of the biodiversity of tropical forests is retained even in forests which are heavily exploited, and improved forestry practices can further enhance the contribution of production forests to conservation (IUCN, in press). The optimum scenario that we might look forward to in the twenty-first century is a totally protected forest estate of about 100 million ha, buffered by a permanently managed forest estate of a further 200 to 300 million ha.

One of the most intriguing problems for conservationists is to reconcile the needs of conservation with those of local people who live in the forests around protected areas. When conservation programmes are based on dialogue with, and the participation of, forest-dwelling people, it is often possible to find a large measure of local understanding and support for forest protection. Considerable work has now been undertaken in developing ecologically sound ways of managing "buffer zones" so that wildlife and people can coexist in carefully managed, near-natural forests. If these buffer zones are judiciously distributed so as to surround the protected areas and also provide corridors between them, their value will be enhanced considerably.


In the past three decades, increased pressure on the tropical forests and a better understanding of the ecology and value of tropical forest species have led to the establishment of a network of national parks and reserves covering some 5 percent of the moist tropical forests. This is clearly not sufficient to meet species conservation objectives, and a major effort is needed to extend the protected area network to include adequate samples of all forest types as well as their full range of biological diversity. Rich industrialized countries must be prepared to help poorer tropical countries meet the costs of such expanded conservation programmes. The proposed convention on biological diversity and legal instrument for forest conservation and management could provide mechanisms for the equitable sharing of costs involved in greatly expanding protected area networks in tropical forests.

However, protected areas alone will not be enough to meet the objective of conserving as many tropical forest species as possible. To achieve this, it is essential that appropriate forest uses are found for additional extensive areas of land in the tropics. These will include forests managed for timber and others for non-wood products. The future of many forest species depends on successful sustainable management.


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Goodland, R. & Ledec, G. 1988. Wildlands: their protection and management in economic development. Washington, D.C., The World Bank.

IUCN. 1980. World conservation strategy: living resource conservation for sustainable development. Gland, Switzerland, IUCN/UNEP/WWF.

Johns, A.D. 1985. Selective logging and wildlife conservation in tropical rain forests: problems and recommendations. Conservation Biology, 31: 355-75.

Poore, D. & Sayer, J. 1987. The management of tropical moist forest lands: ecological guidelines. Gland, Switzerland, IUCN.

Sayer, J. & Wegge, P. The role of production forests in conserving biological diversity. Gland, Switzerland, IUCN; Yokohama, Japan, ITTO. (in press)

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Terborgh, J. 1986 Keystone plant resources in the tropical forest. In M.E. Soulé, ed. Conservation biology: the science of scarcity and diversity. Sunderland, Massachusetts, Sinaure Associates.

Udvardy, M.D. 1984. A biogeographical classification system for terrestrial environments. In J.A. McNeely & K.R. Miller, eds. National parks, conservation and development: the role of protected areas in sustaining society. Washington, D.C., IUCN/Smithsonian Institution Press.

Wharton, C.H. 1968. Man, fire and wild cattle in South East Asia. Annual Proceedings of the Tall Timbers Fire Ecology Conference, 8: 107-67.

World Commission on Environment and Development. 1987. Our common future. Oxford, Oxford University Press.

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