Allometric Equation to Estimate the Belowground Biomass of Abies religiosa Kunth Schltdl. et Cham.

The use of allometric tools allows estimating the biomass of a plant species with greater precision. Tree roots are the least studied part of the vegetation due to the difficulty in obtaining complete root systems. For this reason, the objective was to generate an allometric model to estimate the amount of biomass accumulated in the root system of Abies religiosa trees in El Chico National Park, Hidalgo. For this purpose, 61 trees of A. religiosa were extracted from 0.06 to 3.56 m in height, using a backpack sprayer of pressurized water that detached the soil from the root. The response variable was root fresh weight and the independent variables were height, diameter and age+1, according to the fit of the models tested. Diameter was the variable with the best fit (r2 = 0.95 ± 0.04), obtaining the following equation PFR = (20.918 + D (2.4475)). The allometric model accurately estimates the below-ground biomass contained in the roots, which will allow us to obtain the complete biomass of an A. religiosa forest by having access to data on both the aerial and root components.