Aboveground biomass and carbon estimations for Abies religiosa (Kunth) Schltdl. & Cham. in Mexico: regional allometric models

Accurate estimation of forest biomass and carbon is essential for understanding ecosystem functions and supporting climate change mitigation efforts. This study presents regionally calibrated allometric equations to estimate aboveground biomass and carbon across different forest regions in Mexico, which is an important step toward improving national forest inventories and carbon accounting frameworks. We analyzed a dataset of 1919 trees from 13 Regional Forest Management Units (UMAFORs), collected through a targeted sampling strategy that encompasses all tree diameter classes. We evaluated two additive equation systems to predict aboveground biomass and carbon content by component (stem, branches, and total). Both systems were fitted simultaneously using the MODEL procedure and assessed through multiple goodness-of-fit statistics. The additive equations for tree components and total biomass and carbon showed acceptable fits. Although their overall performance was comparable, system 2 (S2) provided slightly higher predictive accuracy. The resulting region-specific equations offer practical tools for forest managers and policymakers to enhance sustainable forest management and carbon monitoring in the heterogeneous forest landscapes of Mexico.