Estimation of tree biomass, carbon pool and net primary production of an old-growth Pinus kesiya Royle ex. Gordon forest in north-eastern India

Background The data on carbon pool and biomass distribution pattern of old-growth Pinus kesiya Royle ex. Gordon forests are not available. Methods The forest carbon pool and annual net primary production (NPP) were assessed in three old-growth P. kesiya forest stands in north-eastern India, using biomass equations developed from 40 harvested trees between 9 and 63 cm in diameter at breast height (DBH) range. Results Regression models of the form Log(Y) = a + b logD + c (logD)(2) + d (logD)(3) were the best fits for biomass estimation of total tree and its various components. The total forest biomass (which includes live and dead compartments of trees, shrubs, and herbs) was 460.5 Mg ha(-1), of which 91.2% was in the aboveground and 8.8% in the belowground compartment. P. kesiya contributed 77%, broad-leaved tree species 13.5%, shrubs 0.12%, herbs 0.03% and litter 0.5% to the total forest biomass. The total ecosystem carbon content of the forest including soil organic carbon pool was 283.1 Mg C ha(-1). The annual net primary production (NPP) of the forest was 17.5 Mg ha(-1) yr(-1). Conclusion The estimated total forest biomass and carbon pool of the P. kesiya forest were greater than for the other pine forests studied world-wide.