Evaluation of Different Modeling Approaches to Estimating Total Bole Volume for Pinus occidentalis, Swartz in Different Ecological Zones

Pinus occidentalis, Swartz is the primary timber species in the Dominican Republic (DR). Despite its economic importance, studies conducted on this species are very scarce, making it difficult to estimate current inventory levels. This study aims to enhance the accuracy of estimating total bole volume of P. occidentalis in different ecological zones (EZs) within La Sierra, evaluating and comparing two established volume equations—combined variable and Schumacher-Hall—across nine modeling variants (MVs). An indicator variables analysis determined the necessity of distinct equations for two EZs. Fitting included both linear and nonlinear models. Our comprehensive statistical analysis included goodness-of-fit metrics to evaluate each model variants performance rigorously. Modeling variant SH02 was most effective in the Dry Ecological Zone, showing superior performance in both fitting and validation phases. Similarly, SH03 emerged as the best fit for the Combined Intermediate and Humid Ecological Zones, achieving the lowest overall ranking sum among tested variants. The SH equation variants SH02 and SH03, provide reliable and precise volume estimations, allowing optimization of forestry management practices for P. occidentalis trees. The SH models outperformed the CV model variants consistency in parameter estimation. This tailored approach employed ensures more accurate volume predictions, which is crucial for sustainable management and conservation efforts.