Variability in Transport Properties for Blackbutt Timber in New South Wales: Within and Between‐Tree Variability

Variability is a key issue in the processing of biological materials, in this case the hying of hardwood timber. This paper reports the measurements of variability of transport properties. which are relevant to the drying of blackbutt, Eucalyptus pilularis Sm, from northern New South Wales. Specifically, within‐tree and between‐tree variations are reported for two blackbutt regrowth logs. An analysis of variance showed that some timber properties were affected by the board positions within‐trees and between‐trees. Circumferential and radial efects were significant for the within‐ tree variability of most transport properties. Similarly, radial and circumferential effects were signlficant for most of the transport parameters between trees, but can be tentatively stated because only two regrowth logs were assessed. Timber boards with high initial moisture contents had higher rates of diffirsion and low basic densities using principal components analysis. A possible reason is that if there is less wood material per unit volume, these vacant spaces may be occupied by water, and there is also less resistance for diffusive transport of moisture.