Allometric models for aboveground biomass estimation of the mangrove Avicennia schaueriana

As mangroves become recognized as important carbon storages, the need for reducing the uncertainty of carbon inventories becomes increasingly emphasized. Accordingly, the objective of this study was to develop allometric models to estimate the total aboveground biomass (AGB) and the biomass per compartment of Avicennia schaueriana and to compare them with other models previously published for the genus Avicennia. Fifty three A. schaueriana trees, with different diameters at breast height (DBH) and height, were felled in a mangrove from Southeastern Brazil and their dry weight determined. Simple linear regression analysis was used to develop the equations after log-transformation, using the following independent variables: DBH and DBH2 * height. All the equations were significant and presented high R (a) (2) (adjusted coefficient of determination). DBH provided the lowest SEE (standard error of estimation) in the regressions associated to leaves and total AGB, while DBH2 * height generated the most precise regressions for trunk, branches, and twigs. In comparison with other 11 equations previously developed for the genus Avicennia, the equation developed in the present study for total AGB showed the lowest mean deviation in relation to trees with known biomass, underscoring the importance of developing species- and site-specific equations.