Tree Biomechanics: A White Paper from the 2012 International Meeting and Research Summit at The Morton Arboretum (Lisle, Illinois, U.S.)

The International Society of Arboriculture, in conjunction with The Morton Arboretum (Lisle, Illinois, U.S.), convened Tree Biomechanics Summit in September 2010 – bringing together a panel of internationally-recognized experts in the fields of tree biology, tree structure, structural engineering, computer modeling, and arboriculture. Following two days of public research talks on the state of tree biomechanics research, presenters were invited to attend a researcher summit to discuss persisting research gaps and prioritize research needs. Over the course of the event, summit attendees identified five priority research areas: 1) improving efforts to assess mechanical failure potential in trees; 2) modeling the impact of mechanical loading on trees; 3) understanding the mechanisms and modes of tree failure; 4) understanding tree growth response to mechanical loads; and 5) increasing the effectiveness of tree risk mitigation practices. Beyond research priorities, summit participants discussed opportunities for advancing future tree biomechanics research efforts, including the creation of a formal working group dedicated to the subject.

Tree Biomechanics Literature Review: Dynamics

Tree biomechanics studies using dynamic methods of analysis are reviewed. The emphasis in this review is on the biomechanics of open-grown trees typically found in urban areas, rather than trees in forests or plantations. The distinction is not based on species but on their form, because open-grown trees usually grow with considerable branch mass and the dynamic response in winds may be different to other tree forms. Methods of dynamic analysis applied to trees are reviewed. Simple tree models have been developed to understand tree dynamic responses, but these largely ignore the dynamics of branches. More complex models and finite element analyses are developing a multimodal approach to represent the dynamics of branches on trees. Results indicate that material properties play only a limited role in tree dynamics and it is the form and morphology of the tree and branches that can influence the dynamics of trees.