ZLV Online

The article compares selected soil chemistry parameters obtained by the BioSoil survey on the basis of the forest site classification categories that are used in the Czech Republic. The limited number of BioSoil plots (146 in the Czech Republic) enables the evaluation of only the most common categories, which, however, are represented in the majority of the forest area. Trophicum series is characterised by significantly higher base cations content as well as higher cation exchange capacity and base saturation than that of Acidophilum. When analysing lower hierarchy units of the Czech forest site classification – its edaphic categories – there are significant differences in all the evaluated parameters between the nutrient rich and the acidic edaphic category apart from the nitrogen content and the pH(CaCl2) in the lower mineral soil (40–80 cm). The nutrient medium edaphic category represents transition between the others. However, the number of plots with deficit of Ca, Mg and K exchangeable contents is considerably higher in all three edaphic categories. Our results suggest that in the case of calcium the situation is critical because of the lack of the possibility to increase its content by weathering. The base saturation values of 50–70% of the plots are below those that are expected in accordance with the forest site classification system. The automatic use of the current forest classification categories may thereby constitute a serious risk to the sustainability of forest production, especially when assessing the suitability of stands for total biomass harvest or planting of fast growing tree species.