Geographical distributions of carbon in biomass and soils of tropical Asian forests

Abstract

Abstract Estimates of geographically referenced carbon densities and pools in forest soils and vegetation of tropical Asia were modeled using a geographic information system. Spatial data bases of climatic, edaphic, and geomorphologic indices, and vegetation were first used to estimate the potential carbon densities (without human impacts) in above‐ and below‐ground biomass of forests in 1980. The resulting map was then modified to actual carbon density estimates as a function of population density and three climatic regimes. Soil organic carbon estimates were generated by calculating mean carbon densities, to 100 cm depth, from pedon data for tropical forests, stratified by soil texture classes and climatic regimes. The means for each class were assigned to a texture/climate map for all of tropical Asia. The average carbon density for the tropical forests of Asia was 255 Mg ha‐1 in potential biomass, 144 Mg ha‐1 in actual biomass and 148 Mg ha‐1 in soils, which correspond to total carbon estimates of 74, 42, and 43 Pg, respectively. Three out of the 14 countries considered (Indonesia, India, and Myanmar) accounted for about 70% of the total carbon pools in tropical Asian forests. Carbon densities and pools in vegetation and soil varied widely by ecofloristic zone and country.