Rebuilding of species composition of xerothermic grasslands in selected research areas in the Ojców National Park
The paper contains the results of monitoring of xerothermic grassland management conducted in the research areas Górkowa Skała and Grodzisko in the Ojców National Park. In Górkowa Skała active protection was implemented for the first time in 2005. In Grodzisko, in turn, the first protection measures were taken as early as 1982, but their systematic implementation was started only in 2000. Already at the current stage of investigation positive effects produced by these measures can be observed, especially in areas with relatively shallow soil profiles (around 30 cm). Plot monitoring results showed, among other things, an increase in the abundance and frequency of occurrence of grassland species preferring full-light conditions with periodic shading that grow in poor and dry soils. However, the obtained results also confirmed the assumption that the implementation of grass mowing, shrub clearance and plant biomass removal alone is not sufficient to ensure the restoration of a typical grassland species composition in deeper soil profile areas. Thus, it seems necessary that these protection measures should be supplemented by controlled grazing of farm animals.