About WLA

To assess the failure probability of a tree, according to the basic principles of structural analysis it is necessary to take three main points into consideration:

The horizontal (own weight) and vertical (wind load) forces that affect the tree.
The material properties of the wood.
The size and shape of the stem cross section (residual wall thickness) at the testing level.

Most contemporary methods for tree stability assessment concentrate on scrutinizing internal defects, residual wall thickness and in some cases on testing various material properties of the tested wood. To take into account all factors affecting tree stability, it is necessary to add an analysis of the forces that affect the subject tree during high wind events.