These species-poor forests are dominated by Abies alba, frequently mixed with Picea abies and Pinus sylvestris; these species also dominate the shrub layer. The herb layer is formed of acidophilous graminoids, ferns and Vaccinium myrtillus. A moss layer is well developed. This association occurs on different types of nutrient-poor siliceous bedrock, mainly on plateaus and gentle slopes from the colline to submontane belt. On most sites these fir stands developed from natural beech forests under long-term human impact.