TAPER AND COMMERCIAL VOLUME SYSTEM FOR Pinus patula Schltdl. et Cham. IN ZACUALTIPÁN, HIDALGO STATE

Abstract

A group of taper and commercial volume functions to estimate diameter at different stem heights and total commercial volume, as well as the distribution of timber products for Pinus patula in even-aged regenerated stands under the seed tree method are described in this paper. Seventy eight trees were destructively sampled and measured, and bolt volumes were calculated with the overlapping bolt method which allows to get total and partial volumes in a more accurate way. Data base was used to fit 11 compatible taper-volume systems that included segmented models. All the systems were fitted by the simultaneous estimation of parameters by the with the maximum likelihood and full information method to optimize fitting while simultaneously minimizing the errors in a combined way. The segmented system proposed produced the best fit as it explains 97.06 and 98.09% of the taper and commercial volume variability. The inflection points were estimated at 1.34 and 82.3% of the relative total stem height, which suggests that under intensive forestry, tree stems become more cylindrical than in stands without intensive management, where the inflection points are estimated at 5.7 and 22.4% of relative total stem height.