Soil organic carbon pool in Indian forests

A database of published measurements (with depth) of soil organic carbon (C) containing information on location, soil type, texture, measured/estimated bulk density and forest type in Indian forests was prepared. It was used for estimating soil organic C densities for various forest types for two-depth classes (0-50 and 0-100 cm). The mean soil organic C density estimates for top 50 cm based on 175 observations ranged from 37.5 t/ha in tropical dry deciduous forest to 92.1 t/ha in littoral and swamp forest. The mean soil organic C density estimates based on 136 observations ranged from 70 t/ha in tropical dry deciduous forest to 162 t/ha in montane temperate forest for top 1 m soil depth. The estimated soil organic C densities were combined with remote sensing based recent forest area inventory (64.20 Mha) by Forest Survey of India [The State of Forest Report, Forest Survey of India (FSI), Ministry of Environment and Forest, Govt. of India, Dehradun, 80 pp.] to arrive at estimates of soil organic C pool by major forest types of India. The total soil organic C pools in Indian forests have been estimated as 4.13 PgC(1) in top 50 cm and 6.81 PgC in top 1 m soil depth. These estimates may be taken valid for 1980-1982 period on which the remote sensing based forest area assessment was made by FSI. The historic loss in forest soil organic C pool (1880-1981) in top 1 m soil depth has been estimated as 4.13 PgC. The estimated soil organic C densities by forest types can form input in models for estimating net C release from forests by deforestation as well as in estimation of historic loss in soil organic C pool in Indian forests. (C) 2002 Elsevier Science B.V. All rights reserved.