BIODIVERSITY OF TROPICAL PEATLAND IN SOUTHEAST ASIA

摘要

Natural lowland peat swamps of Southeast Asia support forest vegetation forming a catena of types from their perimeter to centre, a change that is reflected in variations in canopy height, peat thickness, waterlogging and nutrient availability. Recognition of the biological, environmental and economic importance of tropical peatlands has been a slow process. The earliest interest in the peat swamp forests of Southeast Asia was in the 1930s by British foresters working in the former British Protectorates of Malaya, Sarawak and Brunei and Dutch scientists in Kalimantan and Sumatra. The ecological and taxonomic studies of peat swamp forests of northern Borneo by J.A.R. Anderson became a benchmark for all subsequent research on tropical peatland. Many plant species are restricted to this stressful habitat and some are endemic to it. Several historical accounts of the fauna of tropical peat swamp forests suggested that animal diversity was low but more recent ones, for example in the upper Sg. Sabangau catchment of Central Kalimantan, show the opposite that they are vital habitats for many rare and endangered species of animals and plants including orang utan (Pongo pygmaeus). By the end of the 1980s, extensive areas of peatland in Indonesia, Malaysia and Thailand had been drained and converted to agriculture for a large range of crops including rice and vegetables and plantations of oil palm and paper pulp trees. Associated problems of peat shrinkage, subsidence, nutrient deficiency, toxicity and low plant productivity are also documented. Deforestation, drainage and conversion of tropical peatland to other land uses has continued apace since then over increasingly larger areas with consequent problems of fire, flooding, greenhouse gas emissions and poverty all of which have had negative impacts on biodiversity. These are now regional and global problems some of which will be the subject of other presentations at this congress.