Charcoal and organic geochemical properties as an evidence of Holocene fires in tropical peatland, Central Kalimantan, Indonesia

Abstract

A fire-history study of the tropical peatland of Central Kalimantan has been conducted using charcoal and organic geochemical analyses. A-153 cm core was taken from Kalampangan. Charcoal analysis and ¹⁴C dating were used to understand the fire pattern, and organic geochemical analysis was used to identify environmental changes caused by fires. The peat formed from 9472 - 8981 to 7624 - 7424 cal. yr BP (calendar years before present) coeval with the development of the wet and warm climate of the Southeast Asia region. Fire frequently occurred in the study area during the peat formation. The fire intensity must have been low to have allowed continous peat formation. The record indicated that two comparatively severe fires, or fire periods, occurred in the study area between ca. 7500 and ca. 7600 cal BP and between ca. 6400 and ca. 6500 cal. yr BP. In addition, several fires caused nitrogen loss from the peatland and destroyed the plant communities. Re-established plant communities gained nitrogen for photosynthesis from the atmosphere through bacterial fixation. As a consequence, low quality litters with more negative δ¹⁵N were produced.