Abstract

SIONE, S. M. J. et al. Biomass allometric models for Vachellia caven Mol. Molina in native Espinal forests (Argentina). Quebracho (Santiago del Estero) [online]. 2020, vol.28, n.1, pp.20-33.  Epub June 01, 2020. ISSN 0328-0543.

The capture and fixation of atmospheric CO2 is one of the environmental services provided by native forests. Tree biomass is an indicator of carbon stocks and can be estimated using allometric models that must be accurate, unbiased and local. The objectives of this study were to determine the individual aerial biomass of Vachellia caven and its distribution by structural component; estimate the diametric class-based biomass expansion factors (BEF) and obtain allometric models for the estimation of the aerial biomass of the El Espinal, a native forests of Entre Ríos, Argentina. The dasometric variables of 30 individuals of different diametric classes were measured and both the total and componential (trunk, branches of more than 5 cm in diameter, and branches of less than 5 cm + leaves + flowers + fruits) biomass determined using the destructive method. To select the best biomass estimating models, goodness of fit indicators were used: the adjusted coefficient of determination (r.), mean squared predicting error, the PRESS statisticgraph, the Akaike and Bayesian’s Information Criteria and the Furnival index. The best-fit models were based on diameter at breast height (BHD), crown area (ca) and total height. The best model was: Ln(Bt) = -1,69 + 1,74 * Ln(dbh) + 0,41 * Ln(ca). The BEF values varied between 3.1 and 5.8, and were significantly higher in individuals with larger diameters. The models developed in this work present high accuracy (r2 adj. ≥ 0.92) and can be applied in the native forest area of the province of Entre Ríos (Argentina) in V. caven individuals with diameters between 5 cm and 25 cm.

Keywords : carbon pool; native species; models; Fabaceae; estimating functions.