Summary:

Xerothermic swards occurring in Poland are extremely valuable communities because owing to the presence in them of plant species originating from warmer climatic zones they increase the biodiversity of domestic grass ecosystems. They also contribute to improvement of landscape amenities in the areas where they occur. The Malopolska Upland is a region where xerothermic swards are quite numerous. Generally they cover small areas, usually on sites where warm and dry habitats are found, mainly on strongly sun-heated slopes with southern aspect. Four plant alliances are present in the xerothermic swards on the Malopolska Upland Sisymbrio-Stipetum capillatae alliance can be encountered on gypsum rocks 129 covered with thin layer of loess soil. Another alliance forming on gypsum substratum covered with slightly thicker loess layer is Thalictro-Salvietum pratensis assemblage. The alliance frequently found on the Malopolska Upland is Inuletum ensifoliae covering the southern steep slopes of the terrain elevations developed from senonian marles. The fourth alliance of xerothermic vegetation commonly present on the Malopolska Upland is Adonido-Brachypodieto pinnati plant assemblage, encountered on deeper loamy-clay or humus brown soils similar to chernozems. Xerothermic swards, which are not climatic assemblages undergo a natural plant succession, changing into forest ecosystems. Therefore, human interference is crucial to maintain xerothermic plant alliances. It involves prevention of self-afforestation by cutting or burning the sward or active protection, i.e. removal of trees and bushes encroaching xerothermic swards.