Allometric Relationships for Estimating Stem Volume of Rubber Tree (Hevea Brasiliensis Muell-Arg.) in Bangladesh

摘要

The estimation of stem volume is needed for both sustainable planning of forest resources and for studies on the energy and nutri-ents flows in ecosystems. Tree volume equation provide to the tree biomass and carbon estimation in non-destructive way. The aim of this study is to developed allometric relationships for estimating stem volumes of rubber tree ( Hevea brasiliensis Muell-Arg.) were investigated in monoculture plantations of Bangladesh. The various allometric relationships between stem volume and different tree dimensions were tested and the values of coefficient of determination ( R~(2) ) were used to compare strength of these relationships. Although the allometric equations were highly significant ( P<0.001 ), there were considerable variations among them which was also indicated by R~(2) value. The results suggested that tree volume is more correlated with simple G (stem girth at 1.3m height from ground). The allometric relationships of stem volume to various dimensions such as G~(2) and LnG did not improve the allometric strength in comparison to simple G which was also reported for some other tree species. The multiplication of tree height, H and girth, G in the allometric equation gives a little improvement to consider the degree of fitness. However, in this plantation, girth at breast height, GBH only showed a very strong accuracy of estimation ( R~(2) =0.953) especially when used variable G . Therefore, for stem volume estimation, it is recommended to use independent variable G~(2) in the allometric equation. The paper describes the tree volume allometry in details which has significant importance in the field of silviculture and forest management.