Biomass in native and planted forests has been increasingly estimated for several purposes in Brazil. The idea of this work was make two assumption before defining the model, using regression or ratio to estimate biomass: i) the metric units of independent variables in a model should be composed to keep the same metric unit of the dependent variable, ii) the additivity of the components. The objective was established a simple and consistent biological model using ratio estimate and compare its performance with regression modeling WNSUR (weighted-nonlinear seemingly unrelated regressions). The biomass estimation model was applied on stands of Acacia mearnsii in the state of Rio Grande do Sul - Brazil, which include a sample of 670 trees in an age range of 1 to 10.75 years. The modeling of the biomass components was performed using: i) ratio estimate applied to the general model: , where = biomass of a given component: stem, crown or total, in kg; = Scale Coefficients Proxy of Density, kg.m-3; = cylinder volume which is based in dq, in m³, e = error associated to the estimate, in kg; ii) Spurr and Shumacher-Hall’ models fitted by WNSUR. The results obtained by ratio estimates and WNSUR were similar. The fitted model by ratio estimate, for total biomass or its components, proved to be of great interest for biomass estimation and consistent when compared to the results obtained by WNSUR estimates (traditional method). The proposed model, using ratio estimates, is appropriate and promising for modeling of tree biomass.
No datasets are available for this submission.