Principle species colonised

Birch

Area affected

principal branches or main stem. frequently linked to injuries or dieback brought on by other circumstances; when the fungus is dormant in the wood, this can induce it to grow.

Type of decay

Brown-rot

Fruit body / fungal structures

A bracket with a white pore-bearing surface underneath that is 50 to 300 mm across, light brown, smooth, and eventually cracking above. The texture is initially soft before turning corky. occurring separately but frequently in close proximity to other brackets.
Seasonality and perseverance Annual and very brief, although they can develop whenever favourable circumstances are met and last for a year or longer following death.

Significance / Effect / Impact

In southern Britain, this is the primary fungus that causes standing birch to rot. Brown rot typically develops quickly and causes the stem to snap, but decay rarely happens unless the tree was already ill or damaged.