Biomass equations for Castanea sativa high forest in the Northwest of Portugal

There is considerable interest today in estimating the biomass of trees and forests for practical forestry issues, sustainable management, carbon and nutrient flux and other scientific purposes. For these reasons, aboveground biomass was studied in Castanea sativa high forest stands located in the Northwest of Portugal. The most widely used procedure for stand biomass evaluation is the regression estimation method, in which the stand biomass is predicted through the sum of the predicted biomass of individual trees. In this study, thirty-four old sweet chestnut trees, located in three stands, were felled, measured and weighted to evaluate the aboveground biomass by components. Several linear and nonlinear equations were fitted by the least squares method to select a model that predicts total tree aboveground biomass as well as bole-wood, bole-bark, branches, leaves and flowers biomass components as a function of DBH (diameter at breast height) and total height. For each component it was selected the model which fit better