2: PREDICTING PRODUCT QUALITY FROM TREE, INCREMENT CORE, DISC, AND 1-M BILLET PROPERTIES

Butt logs of 15 trees of Eucalyptus nitens (Dean et Maiden) Maiden, aged 15 years, diameter at breast height 55 cm, were cut into appearance-grade lumber and rotary-peeled and sliced veneer, and the second logs into rotary-peeled veneer. A 1-m billet was removed from between butt and second logs of each tree, as well as discs at successive heights. In addition, breast-height increment cores and breast-height measurements of longitudinal growth strain served to characterise the wood properties and processing, product, and clearwood mechanical properties of each tree. Fibre dimensions, density, and microfibril angle were measured by SilviScan on a sample from height 6 m. Boards were quarter-sawn from the 1-m billet and air- and dehumidifier-dried, and internal checking and shrinkage were measured on these boards and on discs from height 6 m. “Sawability ” variables of the butt log (viz log-end splits, flitch movement off the saw, timber crook, and timber conversion percentage) showed strong intercorrelations with one another and with longitudinal growth strain, measured at breast height o