Individual tree growth models for natural even-aged shortleaf pineThis article is part of a larger document. View the larger document here.
Shortleaf pine (Pinus echinata Mill.) measurements were available from permanent plots established in even-aged stands of the Ouachita Mountains for studying growth. Annual basal area growth was modeled with a least-squares nonlinear regression method utilizing three measurements. The analysis showed that the parameter estimates were in agreement with respect to both direction and magnitude to those published by Lynch and others (1999) with data for the first two measurements. Since the tree measurements within a plot were correlated, a linear mixed model (with log-transformed basal area growth as a response) with a compound symmetry covariance structure for trees within a plot was also fitted. The mixed model fitted the basal area growth well, although the least-squares nonlinear model and the linear mixed model were not directly comparable.