Paul McLean1*, Olivier Arnould1, Jacques Beauch^ene2, Bruno Clair1

1. LMGC, University of Montpellier, Montpellier, France
2. Cirad, UMR Ecofog, Kourou, French Guiana
* Corresponding author:
Email:mclean@lmgc.univ-montp2.fr
tel: 0033467149344
fax:0033467144792
Post: Place Eug`ene Batallion, 34095, Montpellier Cedex 5

To investigate the role of viscoelastic properties of wood within the living and growing tree we have developed a system capable of measuring the longitudinal viscoelasticity of green wood using DMA analysis (Menard, 2008). This was experimentally applied to Guianese tree species with individuals selected on the basis of reaction (tension) wood formation. The presence of reaction wood was in the first instance based on stem inclination and growth stress measurements; then verified in the laboratory with microscopic studies, which in turn permitted a further classification on the production or absence of a G -Layer (Onaka, 1949).
Our presentation will follow the classical formula of an introduction to viscoelasticity and wood types (reaction wood, G-Layer), followed by materials with a description of the typical Guianese forest habitat. Some focus will be given to demonstrating the method and justifying our results by means of a validation. Results will show the variation in viscoelastic properties observed with respect to wood type and anatomical characteristics of the selected species. Finally the measured viscoelastic traits will be interpreted to the proposed mechanical role in the living trees.

Keywords: Guianese Hardwoods, Viscoelasticity, Reaction Wood, Growth Strategy

References:
Kevin P. Menard, 2008, "Dynamic mechanical analysis, A Practical Introduction",2nd Edition, CRC Press
Onaka F (1949) Studies on compression and tension wood. Bull Wood Res Inst Kyoto Univ Jpn 24:1-88