ALLOMETRIC EQUATIONS TO ESTIMATE ABOVE-GROUND BIOMASS OF FIVE SPECIES OF TAMAULIPAN THORNSCRUB

Allometric equations were generated to estimate the aboveground biomass by component and total for five species of the tamaulipan thornscrub of Northeastern Mexico. The direct method of felling the tree was used, 27 individuals were cut for each species and with the obtained data, the average dry weight to green weight ratio was calculated for each component. To obtain the biomass, the total green weight of leaves, branches and stem was multiplied by the ratio of dry to wet weight. Six linear and non-linear equations were tested and adjusted using the least squares method. The potential model is the one that best adjusted for the species Eysenhardtia texana (R-2 = 0.96), Havardia pallens (R-2 = 0.99) and Acacia farnesiana (R-2 = 0.99); however, for Acacia rigidula and Diospyros texana the combined variable model was adjusted with R-2 = 0.98 and 0.99, respectively. Base diameter and height are variables that efficiently predict biomass in leaves, branches, stem and total. The use of specific models for a particular species in a given area with local climatic conditions generates a better estimate of biomass.