GENERAL HEIGHT-DIAMETER EQUATION WITH BIOLOGICAL ATTRIBUTES FOR Pinus taeda L. stands

Abstract

The aim of this study was to develop an equation with biological attributes and general applicability, to represent the height-diameter relationship for Pinus taeda L. stands, with and without thinning, in the Middle West region of Santa Catarina state, Brazil. The data came from 652 permanent plots, with 428 to 740 m², located in forest stands with ages ranging from 4.6 to 35.2 years, in which the total heights of about 20% of the trees were measured, in addition to the dominant trees. The functions developed by Harrison et al. (1986) and by Michailoff, Prodan and Stoffels & Van Soest modified by Tomé (1988) were fitted with their parameters linear function of stand variables, by the procedure PROC NLIN of the software SAS^® University Edition, based on the Gauss-Newton algorithm. In general, the Harrison et al. (1986) model, fitted with the parameter  linear function of age (), site index (), coefficient of variation of the tree diameters in the plot () and basal area of the plot (), showed the best statistical performance to represent the height-diameter relationship of Pinus taeda. The fitting of the Harrison et al. (1986) function, with its parameter  linear function of forest stand variables, allowed the development of a height-diameter equation with good statistical performance, biological consistency and general applicability for stands of Pinus taeda.