Allometric equations and parameters for estimating the biomass of planted Pinus merkusii Jungh. et de Vr. forest

We investigated the possibility of formulating broadly applicable equations and parameters for estimating the biomass of planted Pinus merkusii Jungh. et de Vr. forests. We selected four plantations of different stand ages (5, 11, 19, and 24 years) in West Java, Indonesia, and destructively sampled 55 trees after tree census. (1) Coefficients of allometric equations for estimating biomass from tree census data : When the allometric equations contained height data [Yn = a.(DBH2.height) b], we did not detect significant differences between forests in the predictor variables in the equations. (2) Parameters for estimating biomass from stem volume data, i.e., basic density, biomass expansion factor, and root-to-shoot ratio : Some parameters obtained by this study differed from the trends in the default values in the Good Practice Guidance for Land Use, Land Use Change and Forestry, provided by the Intergovernmental Panel on Climate Change. Those default values should thus be refined to reduce errors. (3) Other parameters : Using tree census data collected at 20 sites in Indonesia by the Forest and Nature Conservation Research and Development Center, chrono-sequential changes in biomass were estimated using an allometric equation obtained in the present study. The estimated stand-level biomass of a 21-year-old stand ranged from 161.75 to 456.34 t ha(-1) and, according to multiple-regression analysis, varied significantly with tree density and site index.