How Do You Rate This Publication?       

Title:	Assessing age- and silt index-independent diameter growth models of individual-tree Southern Appalachian hardwoods
Author(s):	Mcnab, Henry W.; Lloyd, Thomas F.
Date:	1999
Source:	Proceedings First International Conference on Measurements and Quantitative Methods and Management & The 1999 Southern Mensurationists Meeting. p 172-189
Description:	Models of forest vegetation dynamics based on characteristics of individual trees are more suitable to predicting growth of multiple species and age classes than those based on stands. The objective of this study was to assess age- and site index-independent relationships between periodic diameter increment and tree and site effects for 11 major hardwood tree species. Model formulations of western conifers were evaluated by multiple regression for significance of three types of variables affecting diameter growth: tree size, competition, and site effects. Many variables were highly correlated with diameter growth but were also intercorrelated. Importance of size or competition variables differed by species and parsimonious models of highly significant (p<0.01) variables explained an average of 60% of the total variation associated with diameter increment. One or two topographic or geographic site-effect variables were significant in models for seven species. but accounted for little (<5%) variation. Detailed evaluation of a yellow-poplar (Liriodendron tulipifera) model indicated prediction errors were not correlated with tree size. Stand age, or site index. Validation testing of the yellow-poplar model with independent data suggested prediction errors were uniformly distributed, but strongly biased. Unexplained bias was associated mostly with tree size. The formulation of diameter growth models for western conifer species is appropriate for eastern hardwoods, but reasons for the unexplained bias should be addressed.
	View and Print this Publication (1020 KB)
Pristine Version:	An uncaptured or "pristine" version of this publication is available. It has not been subjected to OCR (Optical Character Recognition) and therefore does not have any errors in the text. However it is a larger file size and some people may experience long download times. The "pristine" version of this publication is available here: View and Print the PRISTINE copy of this Publication (1.5 MB)
Publication Notes:	We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information. This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain. Our on-line publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS Webmaster, srswebmaster@fs.fed.us if you notice any errors which make this publication unuseable.
	Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility