Crested polypore

Crested polypore (Latin: Albatrellus cristatus) is a wood-decaying fungus that acts as a pathogen, primarily affecting the root systems and bases of various tree species. In forestry and arboriculture, it is recognized as a cause of root and butt rot, leading to structural instability and the gradual decline of infected trees.

The pathogen is a fungus that colonizes the root tissues of trees. It functions as both a saprotroph and a weak parasite, meaning it can survive on decaying organic matter but actively infects weakened or stressed living trees, gradually decomposing the wood and impairing the tree's ability to transport nutrients and water from the soil to its crown.

This fungus primarily targets coniferous species, including spruce and fir trees. It thrives in environments with high soil moisture and poor drainage. Once established, the mycelium spreads through the root system, often moving from tree to tree in dense stands, which can lead to localized "infection centers" within a forest or orchard.

Symptoms of an Albatrellus cristatus infection are often subtle at first. They include:

• Reduced needle size and chlorosis (yellowing) of the foliage.
• Development of greenish-yellow to brown, lobed fruit bodies at the base of the trunk.
• Brittle, decayed wood in the root collar area.
• Increased risk of windthrow due to root system degradation.

Management and prevention focus on maintaining tree vigor and minimizing root injury. Infected trees should be removed, including their stumps, to reduce the fungal spore load in the area. Maintaining proper soil drainage and avoiding mechanical damage during cultivation are critical preventative measures to ensure that trees remain resistant to this and other wood-decaying pathogens.