Picea abies forests on dry sunny slopes (adrets) of the northern and northwestern Alps, with Vaccinium vitis-idaea and a small admixture of Vaccinium myrtillus on siliceous soils over sandstones and carboniferous schists, with Arctostaphylos uva-ursi, Polygala chamaebuxus, Carex humilis on lustrous schists, with berberis vulgaris, Valeriana montana, Valeriana tripteris on stabilised calcareous screes.