Cerrena unicolor

Cerrena unicolor is a species of bracket fungus in the family Polyporaceae. While it acts primarily as a saprotroph, it frequently behaves as a facultative parasite, causing significant white rot in a variety of deciduous tree species, especially those that are stressed or injured.

The host range of this fungus includes common forest trees such as birch, beech, poplar, and oak. By infecting the inner wood, the fungus causes structural instability, which often results in internal hollowing of the trunk and premature tree death in managed landscapes or forest stands.

The life cycle involves the production of basidiospores on the underside of fan-shaped or bracket-like sporocarps. These spores are wind-dispersed and infect host plants through bark fissures, pruning wounds, or frost cracks. Once established, the mycelium secretes lignin-degrading enzymes that systematically break down the cell walls of the woody tissue.

Environmental conditions conducive to the development of Cerrena unicolor include high humidity and stable temperatures ranging from 15 to 25 degrees Celsius. The fungus thrives in shaded, moist environments, which explains why it is often found in dense forests or neglected orchard stands where aeration is poor.

The economic damage is severe, as the wood becomes brittle and susceptible to breakage during windstorms.

• Sanitary removal of infected trees to reduce inoculum sources.
• Sealing of large pruning wounds to prevent fungal entry.
• Management of stand density to improve airflow and reduce humidity.
• Monitoring for signs of sporocarps on trunks and branches.