Artist's bracket

Systematic position and pathogen type: The Artist's bracket (Fomes applanatus, syn. Ganoderma applanatum) belongs to the kingdom Fungi, phylum Basidiomycota, and family Ganodermataceae. It is a perennial wood-decay fungus. Functioning as a necrotrophic parasite, it primarily attacks the heartwood of trees, causing significant structural degradation.

Diseases and host plants: This pathogen causes white heart rot in a wide range of broad-leaved trees, including oak, beech, poplar, and birch. It is also found on fruit trees in orchards. The fungus colonizes the tree through wounds, broken branches, or root injuries, gradually decomposing the wood and rendering the tree susceptible to structural failure.

Biology and life cycle: The mycelium grows inside the wood, secreting enzymes that degrade lignin and cellulose. The fungus produces large, woody, perennial fruiting bodies (conks) on the trunks. These conks are known for their white pore surface, which can be easily marked, hence the common name. Spores are released in massive quantities and spread by wind to infect new hosts.

Conditions for development and harmfulness: The fungus thrives in moist, shaded environments, making humid forests and dense parks ideal for its spread. Its harmfulness lies in its ability to hollow out the center of the trunk. This severe internal decay significantly reduces the tree's mechanical strength, leading to windthrow and increasing the risk of trunk breakage, posing a safety threat in urban areas.

Protection and control measures: Management is primarily prophylactic. Removing infected trees and disposing of fungal fruiting bodies is essential to minimize spore load. It is crucial to prevent wounding of tree trunks during landscape maintenance. Regular inspection of older, high-value trees for the presence of brackets can help assess the risk of structural failure and allow for timely arboricultural intervention.