Les contraintes de croissance dans les tiges: Modélisation de leur mise en place et de leur fonction biologique

Abstract

During growth, trees accumulate large mechanical stresses in their trunk. This can cause problems such as log end cracks when felling the tree, and cracks or distortions of the sawn lumber. These stresses originate in the effect of self-weight and the development of active stress during wood maturation. In this paper, we present the mechanism underlying stress accumulation during tree growth, which explains the specific stress profiles observed in trunks. The link between these mechanisms and their biological function is outlined. Growth stresses are a source of problems for the forest managers or the wood industry, but they are useful to trees. They maximize the resistance of the trunk to external loads such as wind, and allow them to reorient their stem and control its shape. As a conclusion, we show how a better knowledge of the biological function of growth stresses could help selecting appropriate practical solutions to reduce the stress level in commercial production.