PREDICTION OF WOOD QUALITY IN SMALL-DIAMETER DOUGLAS-FIR USING SITE AND STAND CHARACTERISTICS

Standing stress wave measurements were taken on 274 small-diameter Douglas-fir trees in western Montana. Stand, site, and soil measurements collected in the field and remotely through geographical information system (GIS) data layers were used to model dynamic modulus of elasticity (DMOE) in those trees. The best fit linear model developed resulted in an adjusted R-2 = 0.52 for predictions of individual tree DMOE and an R-2 = 0.85 for predictions averaged on a stand basis, The linear model used was mean annual increment(-1), total tree height, and a GIS-based estimate of soil bulk density. Logical models were also developed to predict membership in dichotomous DMOE categories with 71-82% selected trees meeting their respective DMOE criteria. The inverse relationship between soil bulk density and DMOE could be explained by the soil tree moisture interactions know as least limiting water range.