Hypsometric equation adjustments for multi species clonal plantations of Eucalyptus in the Cerrado Goiano

Abstract

Eucalyptus forests has an important role in the national economy since the wood generated by this activity supplies most of the forest-based industries and, also, by its contribution to reducing the pressure of exploitation in native forests. In recent years, commercial eucalyptus plantations have expanded to new areas, such as the central regions of Braziland, as a result, there is a lack of multidisciplinary studies on clones adapted to these environments. This way this study aimed to adjust 18 traditional hypsometric models and 2 proposed for a six-year-old eucalyptus multispecies clonal test in the municipality of Catalão, Goiás. For the execution of this work, a total of 80 representative trees were randomly selected to adjusted 20 hypsometric models (arithmetic and logarithmic). To select the best models, the regression significance, the coefficient of determination (R²), the correlation coefficient (r), the standard error of percent estimate (Syx%), and the bias through the root-mean-square error were verified (RMSE) and the graphical analysis of the residuals. Most of the evaluated models presented high values of r and R² and low error and bias rates (RMSE). The adjusted models Hyperbolic (a), Naslund (b) and Prodan (c), DBH²/H =1.8142+0.0997*DBH+0.0261*DBH²; and DBH²/(H − 1.3)=2.2342+0.0870*DBH+0.0274*DBH², were the most appropriate for the estimation of the total height from the diametric data of multispecies clonal plantations in the Cerrado of Goiás, in regions with Cerradão phytophysionomy.