Abstract

HERNANDEZ-RAMOS, Jonathan et al. Compatible taper-commercial volume system for Pinus greggii Engelm. plantations in Hidalgo State, Mexico. Rev. mex. de cienc. forestales [online]. 2017, vol.8, n.39, pp.59-70. ISSN 2007-1132.

The accurate determination of taper (d) and the commercial volume (Vc) of the trees is a useful tool for planning of forest plantations management. With the simultaneous fit of compatible equations, d-Vc, uncertainty of the volumetric estimation is reduced by type of product. The aim of this study was to fit a compatible d-Vc system for commercial forest plantations of Pinus greggii in Metztitlán, Hidalgo, Mexico. With data of total height (H), normal diameter (Dn), height and diameter at different heights (Hm and d) of 24 trees, the calculation of total volume was made by the method of overlapping logs. Schumacher-Hall’s total volume (Vt) model and three d-Vc compatible models were used. The models fitted simultaneously with the maximum likelihood technique, in the SAS 9.2 statistical program. The best system was the General Fang and Bailey, as it had the greatest fitted determination coefficient (>0.95) and the lowest root mean square error values in both variables. Heterosedasticity correction was made by weighting the residuals, while autocorrelation was corrected by modeling the structure of errors by a second order autoregressive model. When making the graphics of the predicted values against those observed, a line with a straight tendency was formed and the bias of the simple in d = 3.8 % and in Vc = 4.6 %. The model is reliable to estimate directly the diameter at any height and height to any diameter, and therefore, its commercial volume.

Keywords : Timber harvest; product distribution; forest management; method of overlapping logs; commercial plantations; total volume.

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