Regional Height-Diameter Equations for Major Tree Species of Southwest Oregon.
Authors:
Temesgen, H. Hann, D.W. Monleon, V.J. USDA, FS
Source:
Western journal of applied forestry. 2007 July, v. 22, no. 3, p. 213-219.
NALT Subjects:
tree and stand measurements forest trees height equations stand density spatial distribution basal area tree crown forest growth forest yields estimation accuracy forest inventory prediction Oregon
Issue Date:
Jul-2007
Abstract:
Selected tree height and diameter functions were evaluated for their predictive abilities for major tree species of southwest Oregon. Two sets of equations were evaluated. The first set included four base equations for estimating height as a function of individual tree diameter, and the remaining 16 equations enhanced the four base equations with alternative measures of stand density and relative position. The inclusion of the crown competition factor in larger trees (CCFL) and basal area (BA), which simultaneously indicates the relative position of a tree and stand density, into the base height-diameter equations increased the accuracy of prediction for all species. On the average, root mean square error values were reduced by 45 cm (15% improvement). On the basis of the residual plots and fit statistics, two equations are recommended for estimating tree heights for major tree species in southwest Oregon. The equation coefficients are documented for future use.
