The brittle cinder is a wood decaying fungus that is often only recognized by experienced tree inspectors due to its usually inconspicuous appearance. It occurs mainly in the lower part of the tree, especially at the root flares and at the base of the trunk. The fruiting bodies appear superficially burned, which led to the name of the fungus. When touched, they feel similar to charcoal and produce a characteristic cracking sound when pressed with a finger.
The fungus primarily decomposes the roots and the lower trunk sections of the tree. This process leads to a type of rot that can significantly impair the tree’s stability and resistance to breakage. A notable feature is that infected trees initially show no visible signs of reduced vitality. However, if the infestation is sufficiently severe, the tree can collapse without warning.
Over the course of the year, different forms of fruiting bodies can be observed. In spring, light colored and clearly visible growth zones of the asexual fruiting stage develop. These are particularly important for visual identification of the pathogen. As summer progresses, these develop into the black, crust like fruiting bodies of the sexual stage. Inside the wood, black demarcation lines often form, indicating fungal infestation.
The brittle cinder causes a soft rot and occurs mainly on deciduous trees. It is much less common on conifers. Infection usually occurs through injuries, for example root damage or bark wounds. Due to its long inconspicuous appearance, the brittle cinder was underestimated for many years, which often led to an incorrect assessment of the public safety risk posed by affected trees.
Our drilling resistance measuring devices help detect defects. Measurement curve 1 shows a reference curve for a beech. Measurement curves 2 and 3 show the curves of a beech with corresponding infestation and the resulting decay.
