Effects of the Northern red oak (Quercus rubra L.) on the forest site

The study aims to document soil forming effects of Northern red oak (Quercus rubra L.) in North Bohemia. The sites correspond to formerlydominating sessile oak (Quercus petraea /Mattusch./ Liebl.) forests. Soil chemistry of the upper soil layers (Of + Oh, Ah, B horizons) was studied in three pairs of stands of both species. Following soil chemical characteristics were analyzed: pH (active and potential), soil adsorption complex characteristics (the content of base cations, cation exchangeable acidity, base saturation), exchangeable acidity (exchangeable H and Al), total carbon and nitrogen content, and plant-available nutrients content (P, K, Ca, Mg). The total nutrient content (P, K, Ca, Mg) was analysed only in holorganic horizons. The results confirmed acidification effects of the Northern red oak in the upper forest soil such as decreased pH, base content, base saturation and nutrient contents, and increased soil exchangeable acidity, especially in the holorganic and Ah horizons. This species can be considered slightly soil degrading in given conditions.