Calibrating fixed- and mixed-effects taper equations
Document Type
Article
Publication Date
8-15-2011
Abstract
Accurate and affordable measurements of upper-stem diameters are now possible thanks to recent advances in laser technology. Measurement of the midpoint upper-stem diameter can be employed to improve the accuracy of diameter predictions along the tree bole. Felled-tree data from a loblolly pine (Pinus taeda L.) plantation was used to evaluate two approaches: (1) calibrating a segmented taper equation by constraining a parameter, and (2) localizing the taper model by predicting the random effects for each tree. The calibration technique is much simpler and produced less-biased prediction of diameters and is therefore recommended. Calibration results were similar for both fixed- and mixed-effects taper models, even though a slight gain in accuracy and precision was attained with the mixed-effects model. © 2011 Elsevier B.V.
Publication Source (Journal or Book title)
Forest Ecology and Management
First Page
671
Last Page
673
Recommended Citation
Cao, Q., & Wang, J. (2011). Calibrating fixed- and mixed-effects taper equations. Forest Ecology and Management, 262 (4), 671-673. https://doi.org/10.1016/j.foreco.2011.04.039