NONDESTRUCTIVE SAMPLING FOR BASIC DENSITY IN EUCALYPTUS-GLOBULUS AND EUCALYPTUS-NITENS

The feasibility and efficiency of predicting whole tree basic density using either a pilodyn or bark-to-bark core samples is examined for pl antation grown Eucalyptus globulus and E nitens. Each species was samp led from a range of sites and ages across southern Australia. For each tree discs were cut from a combination of percentage heights (0, 10, 20...70%) and fixed heights (0.5 m, 0.7 m... 1.5 m); heights easily ac cessible from the ground. In the first part of this study the efficien cy of evaluating basic density using a pilodyn, was examined with sing le readings taken from each of four aspects at each of the fixed heigh ts. The second part covered the examination of the feasibility of usin g bark-to-bark cores. Both species showed an initial drop in density b etween the ground level and 0.5m, followed by a linear increase in den sity between 10 and 70% of tree height. Density at all fixed heights w as highly correlated with whole tree values for E globulus, but result s were variable across sites for E nitens. For E. globulus optimal sam pling height was 1.1 m above ground, while, for E. nitens, optimum sam pling height was below I.lm. The costs and accuracies of collecting sa mples in the field via the two non-destructive sampling methods are co mpared to destructive sampling. A bark-to-bark core sample is recommen ded as the most cost effective method.