Meeting Abstract

P2.143  Jan. 5  Dynamics of tree structure: growth and stability in forest grown hardwoods BERTRAM, JEA; Univ. of Calgary, Calgary, Canada jbertram@ucalgary.ca

The structural form of a tree changes during the course of its extended lifetime, as does its interaction with the physical and biological environment. Trees must compete with nearest neighbors to secure space in the canopy, but the race to secure access to light requires complex management of the resources available for increases in height and girth; the former determining competitiveness in the canopy while the latter largely determines stability. In this study simple dynamically responsive force transducers were used to determine the stability limits of forest grown hardwoods (oaks and maples) over a range of height (5 � 25 m) and trunk diameter (0.06 � 1.4 m). Stability limits of these trees are defined and related to a variety of structurally relevant features of the organism�s form: height, trunk diameter and root bole form (diameter and volume). It is found that in the early stages of life these trees sacrifice stability for access to the canopy. It is only after they are established in the canopy that substantial structural resources are allocated to features affecting mechanical stability.