Bleeding Oak Crust

Bleeding Oak Crust (Latin: Stereum gausapatum) is a wood-decaying basidiomycete fungus responsible for causing a characteristic mottled or white rot in the heartwood of broad-leaved trees. It is a significant pathogen that affects both standing timber and felled logs, leading to substantial economic impact in forestry.

The host range of this fungus primarily includes oak species (Quercus), although it can occasionally be found on other hardwood trees such as chestnut and beech. The fungus typically gains entry into the host through open wounds in the bark, broken branches, or frost cracks, where the wood is exposed to colonization.

Symptoms of the infection manifest as the development of thin, crust-like fruiting bodies on the surface of the bark, which often exhibit a yellowish-brown or rusty appearance. Internally, the fungus triggers a progressive rot that decomposes structural components of the wood, resulting in a loss of density and mechanical strength.

Favorable conditions for the development and spread of Stereum gausapatum include high humidity and moderate temperatures. The fungus releases spores that are wind-dispersed, allowing it to rapidly colonize fresh injuries on nearby healthy trees or unprotected wood piles left in the forest environment after harvesting.

Management strategies focus on preventive silvicultural practices. Reducing tree injury during logging operations is critical. Furthermore, prompt removal of infected timber and the maintenance of dry, well-ventilated conditions for stored logs can effectively inhibit the colonization and further spread of this destructive fungus.

• Sanitary logging of infected trees.
• Minimizing physical damage to tree trunks.
• Ensuring proper air circulation for stored wood.
• Monitoring forest health for early detection of fruiting bodies.