A generalized nonlinear mixed-effects height-diameter model for Eucalyptus globulus L. in northwestern Spain

FOREST ECOLOGY AND MANAGEMENT

卷:259

Article

Crecente-Campo, Felipe¹  Tome, Margarida²  Soares, Paula²  Dieguez-Aranda, Ulises¹ 

[1] Univ Santiago de Compostela, Dept Ingn Agroforestal, Escuela Politecn Super, Lugo 27002, Spain

[2] Univ Tecn Lisboa, Inst Super Agron, Ctr Estudos Florestais, P-1349017 Lisbon, Portugal

关键词: Growth model;    Random effects;    Calibration;    Unequal selection probabilities;    Weighted regression;    Tasmanian blue gum;   

DOI  :  10.1016/j.foreco.2009.11.036

来源: Elsevier

【 摘 要 】

A generalized height-diameter model was developed for Eucalyptus globulus Labill. stands in Galicia (northwestern Spain). The study involved a variety of pure stands ranging from even-aged to uneven-aged. Data were obtained from permanent circular sample plots in which trees were sampled within different radii according to their diameter at breast height. A combination of weighted regression, to take into account the unequal selection probabilities Of Such an inventory design, and mixed model techniques, to accommodate local random fluctuations in the height-diameter relationship, were applied to estimate fixed and random parameters for several models reported in the relevant literature. The models that provided the best results included dominant height and dominant diameter as fixed effects. These models explained more than 83% of the observed variability, with mean errors of less than 2.5 m. Random parameters for particular plots were estimated with different tree selection options. Height-diameter relationships tailored to individual plots can be obtained by calibration of the height measurements of the three smallest trees in a plot. An independent dataset was used to test the performance of the model with data not used in the fitting process, and to demonstrate the advantages of calibrating the mixed-effects model. (C) 2009 Elsevier B.V. All rights reserved.

【 授权许可】

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