Comparison of nonlinear height-diameter functions for major Alberta tree species

Twenty nonlinear height-diameter functions were fitted and evaluated for major Alberta species based on a data set consisting of 13 489 felled trees for 16 different species. All functions were fitted using weighted nonlinear least squares regression (w(i) = 1/DBHi) because of the problem of unequal...

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Bibliographic Details
Published inCanadian journal of forest research Vol. 22; no. 9; pp. 1297 - 1304
Main Authors Huang, S, Titus, S.J, Wiens, D.P
Format Journal Article
LanguageEnglish
Published 01.09.1992
Subjects
comparisons
diameter
equations
forest trees
height
plant characteristics
Alberta
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Summary:Twenty nonlinear height-diameter functions were fitted and evaluated for major Alberta species based on a data set consisting of 13 489 felled trees for 16 different species. All functions were fitted using weighted nonlinear least squares regression (w(i) = 1/DBHi) because of the problem of unequal error variance. The examination and comparison of the weighted mean squared errors, the asymptotic t-statistics for the parameters, and the plots of studentized residuals against the predicted height show that many concave and sigmoidal functions can be used to describe the height-diameter relationships. The sigmoidal functions such as the Weibull-type function, the modified logistic function, the Chapman-Richards function, and the Schnute function generally gave the most satisfactory results.
ISSN:0045-5067
1208-6037
DOI:10.1139/x92-172