Species-specific wood volume growth models outperform unified model across eucalypt species

Forest ecosystems play an essential role in maintaining biodiversity and mitigating global warming. Intensively managed forest plantations represent a major raw material source for pulp, timber and paper industries. The objective of this study was to apply the model identity test to compare the regression equations used in wood volume estimates of forest species. Five eucalypt species (E. camaldulensis, E. urophylla, E. saligna, E. grandis and E. urograndis) and Corymbia citriodora were evaluated in an experimental area of the Federal University of Mato Grosso do Sul. Five trees in each plot were measured from 56 to 71 months of age to assess the diameter at breast height (DBH) and plant height (Ht), which were later used to estimate the wood volume. The model identity test was applied to evaluate the feasibility of using a single equation to predict the wood volume of all the forest species involved in the study. The complete model had a better fit for the wood volume prediction of the six forest species involved in this study when compared to a single equation. As the tree species studied had different performances in terms of wood volume, species-specific equations should be used to study their growth curves.