Allometric equations to estimate biomass in oak species in Guanajuato, Mexico

Oak forests are important from an environmental point of view, since they have a significant function as a carbon storage. This study is based on a destructive sampling of 165 oak trees with the objective of developing allometric equations to estimate aboveground biomass of six oak species (Quercus rugosa, Q. obtusata, Q. sideroxyla, Q. coccolobifolia, Q. laurina y Q. candicans). Allometric equations as additive system were generated to estimate biomass by structural components (stem, branches and foliage), the of additivity property guaranteed total biomass estimations as well as a generalized model. To improve the predictive capacity of the equations, models that include variables of diameter at breast height, total height and wood density were fitted. The highest percentage of biomass was concentrated in tree stem with 60.6%, while in the branches and foliage a concentration of 36.1 and 3.28%, respectively. The developed equations explained more than 95% of the total tree biomass, and compared with equations developed in other regions for the same genus, showed lower percentual bias. Such equations could be used for the region, as well as in forests with similar structural and growth features to those oak communities in forests from Santa Rosa and Guanajuato mountain ranges.