Modeling Microfibril Angle of Larch Using Linear Mixed-Effects Models

Abstract:

Earlywood microfibril angle (MFA) was determined at each growth ring from disks at breast height (1.3 m) from 6 dahurian larch (Larix gmelinii. Rupr.) trees grown in northeastern China. Significant variation in microfibril angle was observed among growth rings. MFA at breast height varied from 7.5°to 21.5°between growth rings and showed a descreasing trend from pith to bark for each tree. A second order polynomial equation with linear mixed-effects was used for modeling earlywood MFA. The LME procedure in S-Plus is used to fit the mixed-effects models for the MFA data. The results showed that the polynomial model with three random parameters could significantly improve the model performance. The fitted mixed-effects model was also evaluated using a separate dataset. The mixed model was found to predict MFA better than the original model fitted using ordinary least-squares based on absolute and relative errors.

• Periodical: Advanced Materials Research (Volume 267)
• Pages: 516-520
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.267.516
• Online since: June 2011
• Authors: Yao Xiang Li, Li Chun Jiang
• Keywords: Dahurian Larch, Linear Mixed-Effects Models, Microfibril Angle

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