Resumen

CRUZ-COBOS, Francisco et al. Taper and merchantable volume systems for two Pinus species in Durango, Mexico. Rev. mex. de cienc. forestales [online]. 2023, vol.14, n.77, pp.76-102.  Epub 11-Ago-2023. ISSN 2007-1132.  https://doi.org/10.29298/rmcf.v14i77.1383.

The objective of the study was to compare and validate two methodologies in order to estimate the merchantable volume of Pinus cooperi (Pc) and Pinus durangensis (Pd) in the forest region of El Salto, Durango, Mexico. The used data were 164 Pc and 182 Pd trees, whose diameters at different heights and the total height were measured. The 70 % of the dataset was used for training, and 30 % was utilized for testing. Four compatible taper and merchantable volume systems were fitted, three of which were based on volume ratio models, and one, on a segmented taper model. The fitting was performed through iterative seemingly unrelated regression. The criteria for evaluating predictive performance were the adjusted coefficient of determination, the root mean square error, the bias, the Akaike’s information criterion, and the coefficient of variation. The training and testing statistics indicated that the segmented system (SS1) was the most accurate for estimating the merchantable volume and taper of both species. The system based on volume ratio models (RVS2) generated similar results, was more parsimonious and explained 98.3 % of the observed variability in Pc and 97.6 % of that observed in Pd; furthermore, it may prove easier to implement than segmented system for predicting the stem height, stem diameter, merchantable volume, and total tree volume for two studied species. The system labeled RVS2 is recommended for its accuracy and simplicity in estimating the merchantable volume of the evaluated species.

Palabras llave : Tapering; volume ratio models; parsimony; compatible system; merchantable volume; total volume.

        · resumen en Español     · texto en Español | Inglés     · Español ( pdf ) | Inglés ( pdf )