Developing an Empirical Formula for Volume of Timber Availability from Different Species of Trees in Gujarat

Abstract

The standing tree volume is a measurement of the amount of merchantable volume and available growing stock in forests and trees outside forest areas. The precise estimation of the tree log volume plays an important role in sustainable forest management and also in trees outside forest areas. Several scientists have derived various tree log volume calculation formulae, which are used in estimating standing tree volume. The Gujarat State has very rich forest biodiversity. The forest department has done very good work in conserving existing forests and achieved outstanding success in planting and raising trees outside forest areas through a successful social forestry program in the State. The efforts through public participation have resulted in to increase in forest cover of the State. The present investigation was carried out at Gujarat Forest Research & Training Institute, Gandhinagar campus to develop an empirical formula for estimating standing timber availability from different selective tree species of Gujarat. The attempt has been made to measure Girth at Breast Height (GBH), Clean Bole Height (CBH) of selected tree species, and round log volume was calculated using a quarter girth formula assuming it to be a cylinder. Considering principle factors behind tree growth that 1) the height is a function of girth, 2) young aged tree grows at a double rate that in middle age and 3) mature tree hardly puts any height or girth, a general growth formula has been derived. The general growth formula was validated for different species based on actual measurement of effective height. Finally, the empirical formulas were developed based on the Regression of derived formula V = A G 2 10 -5 e bG for different tree species.