BIOMASS INVENTORY WITH TREE TAPER EQUATIONS

A method of using tree taper equations to estimate volume and weight in a forest inventory is presented. Coefficients of the taper equations are estimated using diameter-height pairs measured on the sample trees. In an evaluation, the taper-equation-based estimates of volume had mean square errors ranging from 0.05 to 0.43 m3 per tree. Regression-based estimates had mean square errors ranging from 0.22 to 0.99 m3 per tree. In all cases the mean square error for taper-based estimates was less than one-half of those for regression-based estimates. The taper-based estimates require measurements only on an individual tree for which volume or weight prediction is desired, thereby eliminating the need for the large-scale measurements only on an individual tree for which Volume or weight prediction is desired, thereby eliminating the need for the large-scale measurements needed to develop regression equations. Two sampling schemes combining taper equation use and horizontal point sampling are described. The schemes make use of the integrated form of the taper equations and the probability of selection criterion of horizontal point sampling.