Development of tree height and diameter growth equations for mid-Willamette Valley Douglas-fir

approved: Signature redacted for privacy. David W. hann Equations for predicting height growth, basal area growth and diameter inside bark are presented for Douglas-fir. Basal area growth equations for grind fir are also presented. The growth models were developed for use in an individual tree/distance independent growth simulator. Various model forms and measures of competitive stress were compared in both the height and basal area growth models. The height growth equation is a function of crown ratio and height divided by dominant stand height. Basal area growth is a function of tree diameter, crown ratio, crown competition at the plot level, stand basal area and either site index or predicted height growth. The diameter inside bark equation, used in backdating tree diameters, is a nonlinear function of diameter outside bark. Development of Tree Height and Diameter Growth Equations for Mid-Willamette Valley Douglas-fir