Nondestructive sampling of Eucalyptus globulus and E. nitens for wood properties; II. Fibre length and coarseness |
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| Authors: | A Muneri C A Raymond |
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| Institution: | (1) Cooperative Research Centre for Sustainable Production Forestry CSIRO Forestry and Forest Products, GPO Box 252–12, Hobart TAS 7001 Australia Tel.: +61-362-267948; Fax: +61-362-267901, e-mail: Carolyn.Raymond@ffp.csiro.au, AU;(2) Current Address: Queensland Forest Research Institute, PO Box 631, Indooroopilly QLD 4068 Australia, AU |
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| Abstract: | Within-tree variation in fibre length and coarseness was studied in fifty trees of E. globulus and E. nitens to develop a non-destructive sampling strategy. Trees, aged 5 to 9 years, were sampled across a range of sites in southern
Australia. Simulated core samples were removed at six fixed heights easily accessible from the ground (0.5, 0.7, ... 1.5 m)
and at eight percentage heights (0, 10, 20, ... 70%). Whole-tree values, calculated from percentage height data, were correlated
with the core data to determine the optimal sampling height. Core samples were found to be reliable predictors of whole-tree
fibre length, but results were variable for fibre coarseness. Simulated cores taken from the recommended sampling heights
explained 87% and 71% of variation in whole-tree fibre length for E. globulus and E. nitens respectively and 54% and 45% of the variation in whole-tree fibre coarseness. Fibre length at all fixed heights showed good
correlations with whole-tree values at all sites for E. globulus. For E. nitens the correlations were slightly lower and variable across sites. Results for fibre coarseness varied across sampling heights
and sites for both species. The recommended sampling height for fibre length is 1.5 m for both species, whilst for fibre coarseness,
the recommended sampling heights are 0.9 and 1.1 m for E. globulus, and 0.9 and 1.3 m for E. nitens. Radial orientation of cores was not important and neither fibre length nor coarseness were related to tree size or basic
density. To estimate stand mean fibre length to an accuracy of ±5% would require sampling 9 whole trees or taking cores from
13 trees for E. globulus and 4 whole trees or cores from 8 trees for E. nitens. For estimating stand mean fibre coarseness, 10 whole trees of E. globulus and 7 whole trees are needed for E. nitens. Core sampling for stand mean coarseness would require more trees: 13 to 21 for E. globulus and 11 to 16 trees for E. nitens.
Received 17 September 1998 |
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