INFLUENCE OF SELECTED FACTORS ON WOOD DENSITY VARIABILITY IN GRAND FIR (ABIES GRANDIS/DOUGLAS/LINDL.)

摘要

Grand fir ranks among the promising tree species that have been introduced into the Czech Republic, particularly as a potential substitute for the native European silver fir. This article deals with wood density of grand fir coming from Czech sites and selected factors which influence its variability. Sample trees of grand fir representing different sites were tested for wood density at 12 % moisture content according to the national standards. The obtained value 403 kg.m(-3) is somewhat lower than the density achieved by grand fir in native areas. Horizontal position within the stem proved to be the most important factor affecting the density. Density increased with increasing distance from the centre of the stem towards the bark, reaching its highest values at the perimeter of the stem. Individual trees were found to be another major source of variability. On the contrary, the effect of vertical position on the density variability was low. The cardinal directions proved to have practically no effect. Density was also found to have no major dependence on the width of annual rings, as R-2 was only 0.44.