Relationships between density, shrinkage, extractives content and microfibril angle in tension wood from three provenances of 10-year-old Eucalyptus globulus Labill

Abstract

Density and microfibril angle (MFA) of tension wood and normal wood were assessed in the sapwood and heartwood, from three provenances of 10-year-old Eucalyptus globulus Labill. Density was measured using a modified saturation method that also enabled the calculation of the extractives lost during saturation. Microdensity and MFA were determined by SilviScan 2, a rapid X-ray densitometry and X-ray diffraction system developed at CSIRO. Significant differences were found in density and extractives between provenances and also density between the sapwood and adjacent heartwood from each provenance. This result may explain some of the drying differences between provenances found in an earlier s..