Variation in basic wood density and percentage heartwood in temperate Australian Acacia species

Summary

Species, provenance and within-tree variation in basic wood density and percentage heartwood were assessed in 18 tree-form Acacia species/subspecies (40 provenances) and Eucalyptus nitens (one provenance) from southern Australia. The 229 trees from two 8-y-old trials in the Australian Capital Territory were destructively sampled.

Whole-tree, volume-weighted basic wood densities for the Acacia species were between 568 and 771 kg m⁻ and provenance means were in the range 520–778 kg m⁻. Percentage heartwood, sampled at 20% of tree height, ranged between 2.4 and 43.8% for species and 0.0 and 44.1 % for provenances.

There were highly significant differences (P < 0.001) between Acacia species for basic wood density, the trend in basic density with tree height, and percentage heartwood. Provenance variation in Acacia mearnsii in basic density and percentage heartwood, and in A. silvestris for basic density, was significant (P < 0.05) and could be exploited in breeding programs.

There was some association between basic density and percentage heartwood at the species level, but no association at the provenance within species level.

Keywords:

• species trials
• provenance trials
• genetic variation
• wood properties
• wood density
• heartwood
• Acacia
• Acacia mearnsii
• Acacia silvestris
• Eucalyptus nitens