Aboveground biomass and carbon stock assessment in the Eastern Himalaya foothills along the Indo-Bhutan border

Abstract

Aboveground biomass (AGB) and the distribution of carbon stock was assessed in a swath of territory along the Indo-Bhutan border. This tract between Brahmaputra river’s floodplain and foothills of Eastern Himalayas, is a part of the Indo-Bhutan biodiversity hotspot. Using Landsat satellite data, the analysis assessed spatio-temporal landuse/landcover changes during 1989 and 2019. AGB and carbon stock were estimated using a forest inventory. Total AGB losses were 21.44 and 7.24 Mt in India and Bhutan respectively. Tree density ranged between 107–350 and 253–853 trees ha−1 in India and Bhutan respectively and tended to decrease with increasing tree diameter. Anthocephalus Chinensis (76 trees ha−1), Aphanamixis Polystachya (64), Syzygium Formosum (62) were the most dominant species in India while Quercus Spp (249 trees ha−1), Abies densa (190), Rhodendron (155) dominated in Bhutan. AGB and carbon losses were more marked in India than Bhutan. Land cover changes were not uniformly spatially distributed throughout the study area and dense forests in India decreased at a rate seven times that of Bhutan’s. Consequently, AGB losses in India were three fold those of Bhutan’s.