Wiant's Appalachian Hardwood Weight Equations—Revised

Abstract

Revised model formulations are presented using the original data of Wiant et al. (Tables and procedures for estimating weights of some Appalachian hardwoods, W.V. Agr. For. Exp. Sta. Bull. 659T, 1977). Model forms are presented as functions of dbh and total tree height (THT), dbh and merchantable tree height (MHT), and dbh alone as independent variables. Using the root mean prediction sum of squares statistic (PRESS) statistic, the root mean square residual, and residual plots as the criteria for evaluating prediction accuracy, models using dbh and THT generally out performed those using dbh and MHT as well as models based on dbh alone. In general, newly fit nonlinear models outperformed earlier linear functions and provided a set of new equations based on the field measurement of merchantable height to a 4-in. top rather than requiring the input of total tree height.