Whole tree variation and oblique axes of spatio-temporal variation in Eucalypt fibre morphology with cambial age in E. globulus
by
Irene L Hudson
Department of Mathematics and Statistics, Private Bag 4800, University of Canterbury, Christchurch, New Zealand
Coauthors: Michelle Dalrymple

Eucalypt hardwood cells are the product of physiological and genetic processes starting with the differentiation of the cambium. Factors such as age, growth rate, site, genotype and size of cambial initials determine wood microstructure. It is shown that fibre variation can be referenced to a multiplicity of axes governed by - ring structure, chronological age, height, ring-specific attained height (AH) and cambial age (CA), where CA is related to the time the first vascular cambial cell formed at a given height and ring. Modified spatial algorithms of Legendre, multi-dimensional clustering and discriminant methods were used to confirm segmentation of the tree into partitions with similar morphologies. Multivariate non-linear time series accounting for the volume and 3D geometry of the tree will also be explored for E. globulus. Genetic manipulation of cambial activity, may provide a means of producing fibres with specific dimensions for given end-user geometry.

Results to date show that: Fibres of a specific morphology are formed by cambia of the same or similar age at systematic and consistent partitions of the whole tree; following an oblique directionality from pith to bark and up the stem. Whole tree variation of 8 fibre dimensions - are shown to be strongly associated (P<0.00001) with cambial age (CA) at year of production; and (i) change with growth rings from pith to bark (increasing CA) and (ii) vary directly (P < 0.00001) with CA (decreasing up stem) within each ring.

Date received: July 30, 2000

Copyright © 2000 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cadt-13.