Variation in Wood Characteristics of Eucalyptus tereticornis Smith under High-Density Short Rotation System

摘要

The effect of planting density and sampling height on selected wood properties in high density short rotation plantations was studied in seven-year-old Eucalyptus tereticornis Smith. Four trees each from three planting densities viz. 0.60 x 0.60 m, 0.90 x 0.90m and 1.20 x 1.20 m were randomly selected and harvested. The wood characteristics at four different tree heights i.e. ground level, 30, 60 and 90 per cent of total tree height for all planting densities were studied by taking a sample disc of wood at these heights. The maximum wood percentage and minimum bark per cent were recorded at sixty per cent of total tree height. The moisture content and wood density decreased with the sampling height. Extractives (cold water, hot water and alcohol benzene soluble) decreased from base to top of the tree. The calorific value did not observe any significant difference along sampling height. The lignin content decreased while holocellulose content increased from ground level to top of the tree. The different planting densities observed statistically non-significant values for most of the wood characteristics excepting cold water soluble extractives, where highest value was found for 0.60x0.60m spacing.