Porcelain fungus

Porcelain fungus (Oudemansiella mucida) is a basidiomycete fungus primarily known as a pathogen that affects beech trees. It is frequently observed in deciduous forests where it plays a dual role as both a parasite on living wood and a saprotroph on dead, decaying organic matter.

The disease is caused by fungal mycelium that colonizes the cambium and heartwood. It is classified as a white-rot pathogen, as it secretes enzymes that break down lignin, leaving behind the white, cellulose-rich wood fibers that lose their mechanical strength over time.

The most visible sign of infection is the appearance of distinct, translucent, and slimy white fruiting bodies clustered on the trunks or branches of the host tree. Internally, the wood becomes brittle and structurally compromised, often leading to internal cavitation that significantly weakens the tree's stability.

Development of the fungus is highly dependent on humidity and temperature. It thrives in damp, cool environments that prevent the drying out of the mycelium. The spores are primarily wind-dispersed, allowing the fungus to infect new hosts whenever it encounters an open wound or a weakened bark area.

To prevent the spread and impact of this pathogen, forest management strategies must focus on tree health. Key protection measures include:

• avoiding mechanical damage to tree trunks during logging;
• regular inspection of high-value beech stands;
• sanitation of diseased wood to reduce spore density;
• maintaining proper thinning regimes to reduce humidity around the trunks.