This alliance includes heathlands with Calluna vulgaris, Vaccinium myrtillus and V. vitis-idaea confined to sites without pronounced summer drought and with continuous snow cover in winter, which has a frost-protective effect. Like other heathlands, they occupy acidic, nutrient-poor soils. This alliance is distributed in the Hercynian mountain ranges of western and Central Europe. It may form either the natural vegetation of rock outcrops and areas above the timberline, or secondary vegetation on deforested sites.