Diverse forests of Indonesia have been severely affected by megafires, but the impact of fire on forest vegetation in this region has not been widely studied. We reviewed papers following a systematic methodology to assess the state of the literature on the impact of fires in non-peatland tropical forests of Indonesia. In total, we found 15 papers written in English and 3 papers written in Bahasa Indonesia. Most research has been done in Kalimatan, particularly in East Kalimantan (15 out of 18), with only 2 research projects conducted in Sumatra, and one in Java. In general, forest fires changed forest structure and composition. Fires killed almost all seedling, sapling, and small trees in the under- and mid-story layers. One of the unique species in Indonesian forests, the world´s southernmost naturally distributed pine called Pinus merkusii or Tusam, is fire-prone in some southeast Asian habitats. However, its fire ecology has rarely been examined in Indonesia, despite its prominence for resin production. We quantify differences between burned and unburned P. merkusii forests in the Tapanuli and Kerinci regions of Sumatra. Fires killed more than 60% of P. merkusii trees and reduced tree biomass and carbon by about 40%. Fire killed trees of all sizes up to 60 cm diameter at breast height (DBH), but preferentially killed small trees with DBH less than 10 cm. With increasing pressure of climate change, fire is predicted to become more severe, frequent, and widespread. Increasing research to develop reliable information on fire effects is urgently needed.
Northern Arizona University