Local height-diameter models for Pinus montezumae Lamb. and Pinus teocote Schiede ex Schltdl. in Nanacamilpa, Tlaxcala

Abstract

Field measurement of total height of standing trees imposes practical difficulties that increases time and costs of forest inventories. Moreover, height measurement is prone to mistakes especially in forests with dense understories. Allometric equations are a suitable option to estimate efficiently total height as a function of tree diameter. The aim of this study was to analyze allometric models to fit the total height-normal diameter relation for Pinus montezumae and P. teocote trees in the forest region of Nanacamilpa, Tlaxcala. Database consisted of 583 pairs of total height-normal diameter measurements for P. montezumae and 486 pairs for P. teocote covering a wide range of diameter classes. We evaluated 14 nonlinear and one linear models with regression analysis using the MODEL and REG procedures of SAS^® respectively. Goodness of fit was assessed with R²_adj, bias, root mean squared error, sum square error, mean square error, and Akaike’s information criterion. The best model for P. montezumae was Yang’s model (M2) with an R²_adj=0.91, whereas the quadratic model (M10) was the best for P. teocote with an R²_adj=0.87. Such models described with precision the relationship between height and diameter these tree species in the western region of the state of Tlaxcala.