A volume prediction system for Quercus robur L. in Galicia (Northwestern Spain) based on a volume ratio equation

Eight total-volume equations and four volume-ratio equations (for diameter limits) were fitted to a sample of 225 trees of Quercus robur of different ages. The trees were collected in stands growing in a great variety of site qualities and densities in Galicia (Northwest of Spain). The data employed...

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Bibliographic Details
Published inForest systems Vol. 13; no. 3; pp. 506 - 517
Main Authors Barrio Anta, M., Álvarez González, J. G., Díaz-Maroto Hidalgo, I. J.
Format Journal Article
LanguageEnglish
Published 01.12.2004
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Summary:Eight total-volume equations and four volume-ratio equations (for diameter limits) were fitted to a sample of 225 trees of Quercus robur of different ages. The trees were collected in stands growing in a great variety of site qualities and densities in Galicia (Northwest of Spain). The data employed to develop volume ratio equations have a longitudinal structure so a second order autoregressive model was used to correct the error dependence implicit in this kind of data. Several «goodness-of-fit» statistics were used in order to select the best equations within each group (total volume equations and volume ratio equations) and cross-validation was used to analyse the performance of the model. Finally, the models selected were combined to develop a volume equation with product classification.
ISSN:2171-5068
2171-9845
DOI:10.5424/srf/2004133-00849