Lowland tropical peatlands of Southeast Asia: importance, impacts and prospects

Tropical peatlands, which cover approximately 50 million ha spread across the per humid tropical region, have been largely ignored until recently by Governments, scientists and developers alike because they are difficult to access and have an environment that most people find dangerous and unpleasant. Tropical peatlands comprise approximately 12 percent of the global peatland resource and two-birds of this area is located in Southeast Asia mostly in coastal and sub-coastal areas. The greatest concentration is in Indonesia and Malaysia where they occur in Irian Jaya, Kalimantan, Peninsular Malaysia, Sarawak and Sumatra covering extensive areas of landscape with peat that varies in thickness from half a metre to more than 20 metres. The vast majority of these peatlands are ombrotrophic systems that are extremely acid and nutrient deficient. Many form peat domes elevated above the highest limit of wet season river flooding. They have perched water-tables close to, or above, the surface throughout the year. Their natural vegetation is rain forest that consists of a catena of sub-types extending from the perimeter near to major rivers to the centre of the peatland dome. The principal characteristic of this zonation is replacement of high canopy forest of the edge zone by a dense, low canopy pole forest in the interior. The poor soils that tropical peatlands produce following development, and their waterlogged nature and proneness to flooding, have protected them from major land use conversion pressures whilst there were still adequate mineral land resources. This has now changed and pressures for land for people and crops, especially in southeast Asia, has increased to such an extent that even these peat-covered wildernesses are being drained and converted to agriculture. At the same time awareness of the environmental importance of tropical peatlands has also increased and their role in sustaining several important natural resource functions has become evident. The major role of tropical peatlands in land stabilization, water supply, climate stabilization and carbon balance is only now being realized. Infortunately, pressure to develop tropical peatlands for short-term gain is increasing whilst their long-term environmental importance is being ignored. Large-scale peatland development projects, however, often end in disaster as shown by the recent example of the Mega Rice Project in Indonesia to convert one million ha of peat-covered landscape to rice paddy. The Indonesian Government has now officially abandoned this ill-conceived project, which was commenced without firstly carrying out an independently validated ELA. In the meantime, however, a vast peatland landscape has been degraded, its rain forest destroyed by logging and fire, the peat surface drained by channels that cannot irrigate the land and ten thousand people settled on part of it without hope of economic or social security and sustainability. The cost of rehabilitation is immense. The successor to this project may be no better than the original one since this area is now being proposed for oil palm plantations once again ignoring the environmental conditions and importance of the tropical peatland landscape. There is a pressing need for integrated approaches to the environmentally sustainable management of tropical peatlands incorporating principles of wise multiple use. Several models are now in formulation and the Ramsar Convention has recently adopted a stronger course of action in support of wildlife conservation in large areas of tropical peatland.