The impacts of large-scale, low-intensity fires on the forests of continental South-east Asia

Abstract

South-east Asia’s tropical forests harbour high levels of species richness and endemism. In continental South-east Asia strong rainfall seasonality driven by the Asian monsoon lead to ground-fires during the dry season in most years. How these fires influence the region’s landscape mosaic of evergreen and deciduous forests and the biodiversity they support is poorly understood. In this paper we report on the impacts of the El Niño–Southern Oscillation-induced 1997–98 fires that burned across much of western Thailand. We compare fire effects in the three common regional forest types – seasonal evergreen (SEG); mixed deciduous (MDF); and deciduous dipterocarp – and use data from a 50-ha study plot to evaluate the impacts of fire on these forests. We found few differences among the forest types. The fires created more large gaps in MDF than the other forest types. The SEG experienced greater fire mortality in the smallest size classes, abundant resprouting, and showed some evidence of lagged mortality among larger trees. The resilience of the SEG to fire and lack of major differences in fire effects among the forest types suggest that infrequent landscape-scale fires may have little effect on biodiversity in the landscape mosaic of seasonal tropical forests of continental South-east Asia.