Effects of fire on tree species composition and carbon stocks of a peat swamp forest in Central Kalimantan, Indonesia

Peat swamp forests are important in the global carbon (C) budget because of the huge amount of C stored in these ecosystems, particularly in below-ground components. Indonesia has some of the greatest extent of peat swamp forests globally, yet many of them are being disturbed by fires that are becoming increasingly frequent. In Kalampangan, Central Kalimantan, the tree species (≥4.8 cm diameter) composition, aboveground biomass (AGB) and litter standing crop of peat swamp forests were sampled, and the overall ecosystem C stock estimated, within two 1-ha sampling plots, one of which was undisturbed (natural) and the other previously burned. The AGB and litter standing crop found in the natural forest totaled 341 and 6.77 Mg ha−1, respectively. The AGB declined more than six-fold to 53.2 Mg ha−1, and the litter standing crop declined by about half to 3.30 Mg ha−1 in the disturbed forest; the total number of tree species declined from 114 to 80 per hectare. The disturbed peat swamp lost just over 200 Mg C ha−1 to the atmosphere due to the combustion of tree biomass and the upper layer of the peat, but C stocks still remained very high overall (c. 1100 Mg ha−1) due to the thick layer of peat (>2 m) making peat swamp forest conservation imperative due to their huge carbon stocks.