Family differences in equations for predicting biomass and leaf area in Douglas-fir (Pseudotsuga menziesii var. menziesii).

Abstract

Logarithmic regression equations were developed to predict component biomass and leaf area for an 18-yr-old genetic test of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) based on stem diameter or cross-sectional sapwood area. Equations did not differ among open-pollinated families in slope, but intercepts assuming equal slopes did differ for equations predicting leaf, branch, or bark biomass, or leaf area. These results may be explained by family differences in partitioning between stemwood and bark and between stem and crown. Predictions of biomass and leaf area based on equations developed in this study differed from predictions based on equations from other studies by as much as a factor of two, suggesting that discretion is needed when applying equations to other sites at other stages of stand development and with other ranges of tree sizes.

Citation

St. Clair, J.B. 1993. Family differences in equations for predicting biomass and leaf area in Douglas-fir (Pseudotsuga menziesii var. menziesii). Forest Science. 39(4): 743-755