Previous - Next
This is the old United Nations University website. Visit the new site at http://unu.edu
Forest clearance and loss of biodiversity
Forest clearance and life-support capacity
The forest people: Endangerment or criticality?
Deforestation
and global climate
Drought and fire: Hazards leading toward
endangerment
Studies in the grasslands of Borneo
Urban development and social welfare
Review and conclusions
A logical approach
The review of the accelerating pace of transformation in part I has confirmed that the most geographically extensive consequences of change in the past 40 years have been the conversion of forest to agriculture and forest degradation for timber extraction. In this part of the book, where we turn to the examination of seeming "endangerment" leading toward "criticality," we begin with the consequences of deforestation and degradation for the natural environment of the region, and with the effects of such environmental change on present and future life-support capacity. We defer until chapter 7 the effects on the atmosphere, which - if established as major - have consequences of a truly critical nature far beyond the region.
Direct environmental change has two elements: the effect on the forest and its biodiversity, and the effect on soils and hydrology. Lifesupport consequences need to be considered in the context of three groups of people: the indigenous forest-dwellers themselves, the agricultural and other settlers who occupy former forest land, and the wider regional and national economies, especially those parts dependent on the forest industry. In none of these three cases can the direct consequences of forest transformation be isolated from other factors in change. Paradoxically perhaps, the most complex issues are those that concern the forest-dwellers themselves. These are therefore considered separately in chapter 6, after the larger context is set out in chapter 5. The present chapter, however, considers the issue of biodiversity loss, on which questions of true criticality are often raised in the literature.
We begin with an overview of the present situation, drawing on a wide range of data. This will set the scene both for the rest of this chapter and for those that follow.
The scale of the transformation
In figure 4.1 we present some of the best available general information on the state of the forests in the 1980s, since when there has been substantial further change. A principal source, which uses all this available best information, is Collins, Sayer, and Whitmore (1991). Other sources show the earlier extent of forest, reliably for the Peninsula but very unreliably for Borneo.
Loss of forest and biodiversity
Concerning those large areas of forest that have been totally cleared and converted to other uses or that lie waste, we can state only that there is nothing to be gained simply by bemoaning the past. A great resource has been squandered, and a major part of the habitat of a great range of plant and animal species has been destroyed. Moreover, this has been done with far less than adequate economic return to the two nations concerned (Gillis, 1988a, 1988b). The loss is enormous, more complete in the Peninsula and in Sabah, but the principal issues now concern what is created in place of the old-growth forest, and the future capacity of the forest industries to support people. Anticipating discussion below, however, it is useful to note that some of the cleared land is not likely to be converted to agricultural use in the near future, that some of it will be converted to low-diversity planted forest, and that some land previously converted will probably not remain in agriculture. Quite large areas of hill land in the Peninsula have, in fact, already reverted to secondary forest, with or without planted but unused rubber.
The proportion of the region's biodiversity that has already been lost can only be conjectured. It can already be said that in the Peninsula very little lowland mixed dipterocarp forest now remains wholly unlogged outside the conservation areas (Collins, Sayer, and Whitmore,1991: 188); considerable areas of Borneo are already in the same condition. Total removal of forest for conversion to agriculture certainly involves an enormous reduction of biodiversity and the loss of endemic species that were specific to the sites cleared. Species that have low density of distribution suffer huge erosion when large tracts of forest are removed (Cook, Janetas, and Hinds, 1990). Total clearance over large areas has been characteristic of the eastern Peninsula and a few parts of Borneo in the 1970s and 1980s, but it does not prevail on the scale reported from tropical America. In logged forest under selective systems a significant proportion is damaged, but much remains. While it is true that some surviving specimens may be the "living dead," alive but no longer reproducing (Jantzen, 1973), this is probably true of only a minority. In the degraded forest the extent of logging damage varies widely. Moreover, whereas many mammals and birds are seriously disturbed by logging, others survive quite well (Whitmore, 1984: 273-275). Wherever forest has been converted to Imperata-dominated grassland, however, little animal or bird life remains.
A poverty of hard data
There is very little basis in firm research for the spectacular figures of species loss rates that appear not infrequently in sections of the conservationist literature, and that readily attract media attention. While it is surely true that the forests of Borneo and the Peninsula, like those of other regions, are suffering "accelerating and irreversible loss of biodiversity" (Goodland, Asibey, and Post, 1990), there are insufficient data to quantify this process. It is known that Borneo, even more than the Peninsula, contains an immensely varied and diverse array of plant, animal, and insect species with very high rates of endemism - 32 per cent of terrestrial mammals, 70 per cent of leaf beetles, 50 per cent of flowering plants (Groves, 1992; Said, Salleh, and Nor Hassan, 1992). It represents the centre of diversity for durians, dipterocarps, pitcher plants (Nepenthes), and many others (Sastrapradji, Rifai, and Kartawinata, 1992).
Collections of Bornean plants have been made since the 1820s, and are scattered throughout 54 herbaria in Asia, Europe, and the United States. It is not known in detail which regions are less well represented, though there is a concentration of material on significant sites, such as Mt Kinabalu. In general, knowledge is more complete for Sabah, Sarawak, and East Kalimantan, and for the Peninsula, than for other parts of Borneo. Neither is it known how exhaustive or accurate those collections were, in order to establish a baseline against which species loss may be measured (Mat-Salleh, Beach, and Beaman, 1992).
On the faunal side, while there is knowledge of distributions of the larger mammals and birds, other groups such as insects have been inadequately sampled, especially from Kalimantan. The Committee of Research Priorities in Tropical Biology, in a report to the US National Academy of Sciences in 1980, listed Borneo as one of two critical areas (together with Sulawesi) more in need of biological inventory than any other part of tropical Asia (Mat-Salleh, Beach, and Beaman, 1992). Almost all the scientists presenting papers at a 1990 conference on "Forest Biology and Conservation in Borneo" held in Sabah expressed concern that time was running out, because logging was invading so many localities in which no basic work had been done (Ghazally Ismail, Murtedza Mohamed, and Siraj Omar, 1992). It is only recently that a few permanent research stations have been set up to facilitate longer-term ecological and other studies. Most of these are close to the coast so that interior and mountainous areas are not covered. Specific projects, located in the geographical centre of the island in the hill forests of Central Kalimantan and along the mountainous border region between East Kalimantan, Sarawak, and Sabah, have attempted to fill this void (Bodmer, Mather, and Chivers, 1991; Jessup, Soedjito, and Kartawinata, 1992). Direct impacts of logging on particular flora and fauna are just beginning to be examined.
A significant number of biotic and faunal species may be endangered owing to loss of habitat, but this can really be established only in the case of the larger mammals. The tiger and the elephant are now reduced to very small numbers in the Peninsula, where estimated losses of seven primate species between 1957 and 1975 range from 23 to 57 per cent (Mohd Khan bin Momin Khan, 1988). However, this is based only on estimates of former density applied to the known loss of forest areas; it does not allow for the possible migration of the wildlife concerned. The Sumatran rhinoceros was locally common in eastern Sabah during the early years of the twentieth century (Payne, 1992). It may be close to extinction in the more heavily affected parts of eastern Borneo (Wirawan, 1993), though there were sightings in 1977 along the northern edge of the Kutai Nature Reserve (Cockburn and Sumardja, 1978). Small numbers - perhaps a score - remain in the Tabin Wildlife Reserve, north of Lahad Datu, Sabah, together with 100200 elephants and 50 banteng (WWF, 1987), and there are rhinoceros and elephants, together with all of Borneo's other large land mammals, in the Danum Valley Conservation Area in the same district (Marsh and Greer, 1992). It is believed that for several species, including the rhinoceros, eastern Sabah and adjacent parts of East Kalimantan hold the largest or only remaining populations in Borneo. A few rhinoceros may still be found in the Peninsula (in Endau-Rompin National Park). The Tabin Reserve has almost all been selectively logged since 1970 and the Sabah Foundation retains logging rights to a substantial portion. The World Wildlife Fund (WWF, 1987) suggests, however, that eventually Tabin could become a model for combining species conservation with sustained-yield harvesting of tropical forest. It writes (p. 11) that "one of the reasons for the survival of these animal populations is the low density of human population in the immediate area and the reserve's relative inaccessibility." Nevertheless, some poaching does occur and the institution of proper management is recommended.
Potter worked as a consultant on a survey of the Gunung Palung National Park in the south-western part of West Kalimantan in 1992. Like Tabin in Sabah, the region has a relatively sparse human population, but has a selection of all major forest habitats, from peat and swamp to upland, giving sustenance to an extraordinary wealth of animal species. These include most of the large ungulates, though the last confirmed rhinoceros sighting was in 1939 (MacKinnon and Warsito, 1982). Many wild orangutan are present, ranging through various habitats, and there is an impressive population of proboscis monkeys (Nasalis larvatus), which gather in large nocturnal groups along the swampy river banks. Other monkey species, such as macaques and leafeaters, are common, and the call of gibbons (Hylobates agilis) can be heard in the mornings. One of the reasons for the continued faunal abundance is the fact that the surrounding population is Melayu (Malay), not Dayak. These Muslims do not hunt any animals except deer. Dayaks are to be found at a distance and will harvest animals that are using outside forest corridors to move to or from the park. MacKinnon (1992) has generalized from the Gunung Palung situation to suggest that all remaining large populations of orangutan in Kalimantan tend to be located in Malay areas, a position challenged by others who argue that particular habitat characteristics are equally important (Payne, 1992; Mather, 1992).
Access to Gunung Palung used to be difficult; although it still takes some considerable effort to reach the research station in the heart of the park, road improvements together with faster boats along the coast are reducing the isolation of the park edges. They can now be easily reached from the district centre of Ketapang. Open boundaries along the larger rivers make entry simple and surveillance difficult. Although to date this has not had a severe effect on animal populations (with the possible exception of the monitor lizard, the skins of which are sold), some tree species such as gaharu (Aquilaria malaccensis and other spp.), ramin (Gonystylus bancanus), and medang (Litsea amara) are being selectively felled on a wide scale for sale to illegal collectors. Ramin is a valuable swamp timber; the bark of the medang tree is stripped, a process that kills the tree, then it is used to make mosquito coils; the fragrant gaharu wood is extracted from the diseased heart of Aquilaria trees, which also results in tree destruction. Although such activities have not yet resulted in elimination of these species from the area, there are obvious impacts on forest structure (Potter, 1992).
From the Malesian region have been derived a significant number of the world's crop plants, fruits, and some medicinal plants. Sugar cane and bananas are perhaps the most important of these, together with rice on the margins of the region. There is an enormous range of wild fruit trees, and Whitmore (1984: 265) lists 29 cultivated in, or gathered from, a small area of forest in the eastern Peninsula. Those most useful have long since been domesticated and form part of the dusun, or orchards, found in and around villages all over South-East Asia. However, a high proportion of their wild relatives remain in the forest, used by the small populations of hunter-gatherers, by shifting cultivators who consciously preserve many of them in clearing their swiddens and in the fallow vegetation, and by villagers practicing agro-forestry. Chin (1985: 211-227) details 89 basic plant types and some 200 sub-types, corresponding to at least 95 botanical species as actually planted by the Lepo Ga' Kenyah of Long Selatong on the upper Baram in Sarawak; 74 of these provide food. His total botanical inventory of this area consists of more than 600 collection numbers (p. 9).
Considering the concern being expressed about shrinking crop gene-pools in other heavily affected tropical forest regions (e.g. Smith and Schultes, 1990), this aspect has received rather little attention from the scientific community or government agencies. The situation has now changed, and efforts are being made in the collection, documentation, and preservation of wild species. Work is under way in Sabah on the wild varieties of rice found growing in the forest or in disturbed environments, because it has come to be realized that they have high potential as sources of genes for resistance or tolerance to a number of pests and diseases. The variety Oryza officinalis, for example, which is widespread in Sabah, is resistant to the brown planthopper (Benong, 1992). Research in the upper Bahau River area of East Kalimantan, within the huge Kayan Mentarang Nature Reserve, has discovered 42 varieties of rice being grown in two villages; 24 are upland dry rice and 18 wet rice (Dolvina Damus, 1992). An important part of the scientific studies now being undertaken in this reserve concerns the conservation of traditional crop varieties, which, it is argued, may best be done by maintaining them within their entire agroecosystems (Jessup, Soedjito, and Kartawinata, 1992). Bompard and Kostermans (1992: 69) agree with this approach, noting that the multi-purpose tree gardens in parts of West and East Kalimantan "are sanctuaries of crop germplasm of amazing diversity."' They also make a plea for recognition of the active role of peasants in the conservation of genetic resources.
The Department of Agriculture in Sabah has collected species of wild fruits for planting out in germplasm arboreta as living collections ("ex-situ conservation"), which is another approach. Areas especially rich in wild fruits are also being placed in special Virgin Jungle Reserves in collaboration with the Forestry Department (Wong and Lamb, 1992). The National Committee on Plant Genetic Resources of Malaysia is working towards the conservation of wild fruit, spice, and nut trees so that the value of these resources is now being recognized.
Borneo is in the heart of the distribution area of the genus Mangifera. A total of 21 indigenous species have been recorded as part of a project sponsored by the International Union for Conservation of Nature (IUCN)/WWF in cooperation with the International Board for Plant Genetic Resources (IBPGR) and carried out in Kalimantan from 1986 to 1988 with the cooperation of the Indonesian Institute of Sciences and the Indonesian National Committee for Plant Genetic Resources. The list is not exhaustive because many areas have not yet been investigated. The authors of the study believe that wild mangoes have considerable potential in improvement and breeding programmes, but they note a high degree of genetic erosion as traditional lifestyles are changing and the knowledge that accompanied them is lost.
Local people can recognize and name the many wild mangoes, and they have specific uses for each of them. But the cultural background and natural environment of Javanese people resettled in Kalimantan is quite different. They indiscriminately use the Javanese word "Pakel", which applies to M.foetida, when referring to many wild species for which they have no specific use. (Bompard and Kostermans, 1992: 68)
One might generalize that the progressive displacement of huntergatherers and shifting cultivators from forest areas to make way for settlers from non-forest environments has eroded the bank of knowledge about these forest products, especially those that are rare and specific to particular localities.
Research is also proceeding on medicinal plants in parts of East and Central Kalimantan and among the Murut population of Sabah (Ahmad and Raji, 1992; Leaman, Yusuf, and Arnason, 1992; Riswan et al., 1992; Siti Susiarti, 1992). Such products are still in common use among many groups, especially those living in less accessible regions. Traditional Chinese medicine, even in sophisticated urban areas, continues to employ these plants. In Malaysia, 30-40 species of ginger have been used to cure a range of ailments from rheumatism to indigestion. Research into their medicinal properties has shown several to be positive for anti-microbial use and they are being actively investigated for anti-cancer application in the United States. The Indo-Malayan region is reportedly the centre of diversity for Zingiberaceae, with at least 20 genera and 160 species in Borneo, and 23 genera and 200 species earlier recorded for the Peninsula. There could be more but, like so many other under-exploited, non-timber species, they are disappearing with the vanishing forest before being recorded (Ibrahim, 1992).
The heavy loss of lowland and hill dipterocarp forest has greatly reduced an entire environment, so that a disproportionate share of the wild resources remaining are those of the high mountain areas. The scale of this loss is unknown, and it raises an important issue for the conservation of surviving forests. Not only should the size and nature of areas be matters of priority in conservation, but so should their management, with or without occupiers. To this we now turn in concluding this brief discussion.
