FLAMING PEAT: SYNERGISTIC EFFECTS OF FIRE AND FOREST CLEARANCE ON TROPICAL PEAT SWAMP FORESTS

摘要

Recent burning in the tropical peat swamp forests of Southeast Asia, linked with anthropogenic land-use change, has resulted in widespread environmental degradation across the region. Yet little is known about the long-term natural fire regime in these landscapes. Using fossil pollen and charcoal data from three peat cores collected from Sarawak, Malaysian Borneo, we looked at the incidence and impact of local and regional fire on coastal peat swamp forests over the last 7000 years. Results show that burning has occurred in these wetland ecosystems throughout their history. However, prior to the Colonial era c. 1839, when human presence in the peat swamp forest was comparatively limited, neither local nor regional burning significantly impacted on the forest vegetation. After the mid-19th Century, at the onset of intensified land-use change, fire incidence elevated significantly within these coastal peat swamp forests. Although fire does not correlate with past vegetation changes in these ecosystems, the long-term data reveal that open vegetation, a proxy for human forest clearance, does to a greater extent. However, results suggest that human activity may be strongly influencing and acting synergistically with fire in the recent past, leading to the enhanced degradation of these peatland ecosystems. These findings support present-day concerns about the increase in fire incidence and combined impacts of fire and human disturbance on peat swamp forests, with serious implications for biodiversity and global climate change.