Thickets or scrub of the subalpine zone of the Alps, the Carpathians, the Hercynian ranges, usually at the tree-limit, dominated by shrubby or krumholtz birches, in particular, Betula carpatica, Betula pubescens, often with Sorbus aucuparia ssp. glabrata, Lonicera nigra, Prunus padus ssp. borealis (Padus petraea).