Tinder fungus

The tinder fungus (Latin Fomes fomentarius) is a prominent fungal pathogen that causes white heart rot in various wood species. Classified as a basidiomycete, it primarily acts as a decomposer, yet it poses a significant threat to forest health by infecting weakened or mature trees and systematically breaking down their internal structural components.

This pathogen mainly affects hardwood tree species such as birch, beech, maple, and poplar. The mycelium of the fungus enters the host through wounds, broken branches, or frost cracks, allowing it to establish itself deep within the xylem, where it initiates the decay process that compromises the tree's physiological stability.

The most visible symptom of an established infection is the development of perennial, hoof-shaped fruiting bodies on the trunk surface. As the fungus progresses internally, the affected wood turns pale, becomes soft and fibrous, and loses its structural integrity, eventually leading to stem breakage and the inevitable decline of the tree.

Environmental conditions favoring the development of Fomes fomentarius include high humidity and shaded environments, which are conducive to spore germination. The fungus spreads via basidiospores dispersed by wind, which colonize any exposed wood surfaces, effectively turning trees with poor wound closure into long-term reservoirs for the pathogen.

The impact of this disease is primarily economic, as it destroys the market value of timber and shortens the lifespan of mature forests. Effective management strategies include:

• conducting regular sanitary removals of infected trees
• minimizing mechanical damage to standing timber during harvest
• treating pruning wounds to prevent fungal entry
• maintaining overall forest health through proper spacing and site management