Tree Taper Model Based on Similar Triangles and Use of Crown Ratio as a Measure of Form in Taper Equations for Longleaf Pine

摘要

WC used data from 322 natural longlcaf pine (Pinus pdustris Mill.) trees to include crown ratio as a continuous variable in taper equations. The data were divided into 10 crown-ratio classes and fitted taper equations into each class to detect trends in the coefficients. For application to longleaf pine, we replaced coefficients that exhibited a trend with crown ratio with a function of crown ratio. The inclusion of crown ratio as a continuous variable improved by at least 16 percent the mean square residual for both models. The authors model performed better on the modeling dataset based on fit statistics and on the validation dataset. It also contained fewer parameters and was easier to rearrange to solve for height to a given diameter.