Abstract
Individual tree measurements were available from over 200 permanent plots established during 1985-1987 and later remeasured in naturally regenerated even-aged stands of shortleaf pine (
Pinus echinata Mill.) in western Arkansas and eastern Oklahoma. The objective of this study was to model shortleaf pine growth in natural stands for the region. As a major component of the shortleaf modeling effort, on individual tree-level dbh-total height model was developed in which plot-specific random parameters were filled using maximum-likelihood methods. The model predicts tree height on the basis of dbh and dominant stand height (which could be obtained from a site-index model). The mixed-effects model approach was found to predict the total height beller than the similar models developed previously for this species using ordinary least-squares methods. Moreover, such a model has the appeal of generalization of the results over a region from which the plots were sampled; and also of calibration of parameters for newly sampled stands with minimal measurements.
Keywords
mixed-effects,
dbh,
total height,
dominant height
Citation
Budhathoki, Chakra B.; Lynch, Thomas B.; Guldin, James M. 2008. A mixed-effects model for the dbh-height relationship of shortleaf pine (
Pinus echinata Mill.). South J. Appl. For., Vol. 32(1): 5-11