Abstract


The development of tension wood has been studied in various species of the genus Eucalyptus under a number of natural and experimental conditions. It is considered that the distribution of tension wood in the cases observed is consistent with the view that this tissue is an anatomical manifestation of various regulatory processes associated with the maintenance of tree form and movements of orientation in response to environmental changes. Experiments were performed which demonstrate that the development of tension wood is associated with contraction in the stem or branches and that the resulting movements of orientation result from forces developed during differentiation of the fibres and not as a result of differential osmotic effects in the cambium.