To access the full text documents, please follow this link: http://hdl.handle.net/10459.1/48914

A mixed-effects model with different strategies for modeling volume in cunninghamia lanceolata plantations
Miguel Magaña, Sergio de; Guangyi, Mei; Yujun, Sun; Hao, Xu
A systematic evaluation of nonlinear mixed-effect taper models for volume prediction was performed. Of 21 taper equations with fewer than 5 parameters each, the best 4-parameter fixed-effect model according to fitting statistics was then modified by comparing its values for the parameters total height (H), diameter at breast height (DBH), and aboveground height (h) to modeling data. Seven alternative prediction strategies were compared using the best new equation in the absence of calibration data, which is often unavailable in forestry practice. The results of this study suggest that because calibration may sometimes be a realistic option, though it is rarely used in practical applications, one of the best strategies for improving the accuracy of volume prediction is the strategy with 7 calculated total heights of 3, 6 and 9 trees in the largest, smallest and medium-size categories, respectively. We cannot use the average trees or dominant trees for calculating the random parameter for further predictions. The method described here will allow the user to make the best choices of taper type and the best random-effect calculated strategy for each practical application and situation at tree level.
-Boscos
-Conífers
cc-by, (c) De Miguel et al., 2015
http://creativecommons.org/licenses/by/3.0/es/
article
publishedVersion
Public Library of Science
         

Full text files in this document

Files Size Format View
journal.pone.0140095.pdf 1.569 MB application/pdf View/Open

Show full item record

Related documents

Other documents of the same author

 

Coordination

 

Supporters