This alliance comprises zonal climax forests of Picea abies in the supramontane belt of central European mountains as well as natural azonal spruce forests on soils affected by high water table at lower altitudes. Sorbus aucuparia is a frequent subcanopy tree in the zonal subtype and Betula pubescens in the azonal one. The herb layer is poor in species, dominated by acidophilous grasses and/or Vaccinium myrtillus. The moss layer is well developed and rich in species of mosses and hepatics. Soils are acidic and nutrient-poor with a thick layer of poorly decomposed litter. The range of this alliance extends from the mountain areas of central Europe and Scandinavia to the lowlands of eastern Europe.