Growth-layer-level fibre and wood property variation and interrelationships for two radiata pine trees with mild and severe compression wood

摘要

Within-stem positional variation at the growth-layer level of a wide range of fibre and wood properties was determined for a nominally straight and a severely bent radiata pine. The 16-year-old trees were ramets of the same genotype grown on the same site. Visual compression wood was rated as being absent to mild in the straight tree, and absent to severe in the Bent-tree. Correlations among the property residuals of length, microfibril angle (MFA), modulus of elasticity (MOE), colour L~* and growth-layer width were moderate-to-strong for both the Control- and Bent-tree. In contrast, the property residual correlations between the compression wood indicators (colour L~* and growth-layer width) and density, wall thickness and coarseness, were weak for the Control-tree and moderate to strong for the Bent-tree. Hence, fibre length, MFA and MOE growth-layer-level patterns of change with radial-direction and height-position, vary over the compression wood severity range (absent-to-severe). In contrast, density, wall thickness and coarseness are considered poor indicators of mild compression wood. Growth-layer-level MOE decreases with increasing compression wood severity; an effect which is strongly matched to changes in MFA but not density.