Abundant charcoal in forest soils gives evidence of prehistoric and historic natural and anthropogenic wildfires in perhumid lowland and in seasonal Dipterocarp forest types of continental and insular South Asia. Favorable conditions for the occurrence of historic and contemporary rain forest fires are associated with cyclic droughts caused by the El Niño-Southern Oscillation [ENSO] event. The escalating pressure of wildfires on the Dipterocarp forest biome originates from swidden agriculture systems and forest conversion programs. A detailed study of the ecological consequences of the wildfires of 1982-83 was conducted on an area of 2.7x106 ha of rain forest in East Kalimantan. The results show that Dipterocarps are very susceptible to fire and are replaced by pioneer and fire-tolerant species which occupy the disturbed sites or survive the immediate fire effects. Smoke from forest conversion burning causes considerable environmental problems reducing visibility, and affecting human health. In addition, emissions from forest fires may even influence the atmospheric chemistry on a global scale.