Equações volumétricas para Pinus taeda e Pinus elliottii na FLONA de Caçador, SC.

Abstract

Determining the volume of the forest stand is one of the most important procedures in the forest inventory. In this context, the use of volumetric equations to estimate this variable concerns an effective alternative because it presents good accuracy and leads to cost reduction. The objective of this study was to test volumetric equations for data originating from rigorous scaling of Pinus elliottii and Pinus taeda species, in the Caçador National Forest, SC. For this, 12 regression models were adjusted, six of them arithmetic and six logarithmic. The selection of the best mathematical model proceeded based on the statistical criteria of adjusted coefficient of determination (R²adj), standard error of the estimate (Sγχ), F value of the analysis of variance chart, mean relative deviation (DMR), Chi-square , percent coefficient of variation (CV%) and based on graphical analysis of residuals. The results pointed to the Spurr model combined variation II as the best, followed by the Schumacher-hall model among the logarithmic ones, and among the non-logarithmic ones the selected ones were the Burkhaut II models, followed by the Spurr without B0. Among the four models, Spurr combined variation II presented the best results (R²adj = 0.9925; Sγχ = 0.1078 and CV= 10.57%). A covariance test was performed to verify whether this general model could be used to estimate the two species. The results indicated that it is possible to estimate the volume of the two species through the general model Spurr Combined Variation II: .