EN
Chemical properties and fertility of soils were compared under spruce, mixed and beech stands in four types of forest habitat (mountain broadleaf forest, mountain mixed broadleaf forest, mountain mixed coniferous forest and mountain coniferous forest) in 373 sites of forest monitoring in the Stołowe Mountains National Park, SW Poland. Soils under the spruce stands had higher organic carbon pools in their upper horizons, but lower pH, increased activity of exchangeable aluminum, lower contents of exchangeable base cations, available potassium and magnesium, resulting finally in lower values of the soil trophic index (SIG). The negative impact of spruce monocultures on the physicochemical soil properties was much stronger in the eutrophic habitats (dedicated to broadleaf forest) than in dystrophic ones. Weak positive effect of the beech introduction on soils in the dystrophic habitats indicated that the conversion of the coniferous into mixed or deciduous stands would not cause a rapid improvement in the physicochemical properties deformed previously under spruce monocultures.