This vegetation type is characterized by rapid colonizers of disturbed sites in forest environments, such as the perennial Epilobium angustifolium and the annual Senecio sylvaticus. In successionally more developed stages, grasses such as Avenella flexuosa may dominate. It occurs mainly on well drained acidic soils on nutrient-poor bedrock such as granite and less frequently on nutrient-richer schists, which support stands with Atropa bella-donna. It is typical of deforested sites in places of former acidophilous oak or beech forests or conifer plantations on analogous sites. Other habitats include roadsides, strips of land around railways, boulder accumulations at forest edges, building ruins in forests or ski slopes.