Wood decay leads to loss of tree vigor and vitality, resulting in decline, dieback, and structural failure. Wounds play an important part in this process since they are the primary point of entry for wood decay pathogens. While other factors may also result in decline and dieback, the presence of wounds and/or outward signs of pathogens provides confirmation that wood decay is an underlying problem. Wounds and wood decay reduce the ability of trees to support themselves.
Wounds may result from numerous sources such as lawn equipment (Figure 1), pruning, vehicles, herbicides, insects, wildlife, weather, or objects that girdle or embed in trunks or branches (Figure 2). Once stress or damage from wounds occurs, fungal decay pathogens may enter plants to cause further damage. During rainy seasons and moderate temperatures, many wood decay fungi produce visible reproductive structures, such as shelf-like fungal bodies (Figure 3) or mushrooms.
For more information on tree wounds and related disease problems, including symptoms, causes, prevention, and treatment, review the publication Tree Wounds – Invitations to Wood Decay Fungi (PPFS-OR-W-01)
By Kimberly Leonberger, Plant Pathology Extension Associate and Nicole Gauthier, Plant Pathology Extension Specialist