Abstract
The survey of the flora and vegetation of a suggested Nature Reserve Týnčany Karst is given. This small limestone area is situated in the southern part of Central Bohemia, in the Middle Vltava region.
Týnčany Karst is one of the best examples of the karst phenomenon between Bohemian Karst and the limestone areas in south Bohemia. The karst area is characterised by xerothermic grasslands accompanied by a number of endangered plants (Anemone sylvestris, Caucalis platycarpos, Gentiana cruciata, Orchis morio, etc.) The list comprises almost 420 taxa of vascular plants.
Fifty species are on the Red list (Procházka 2001). Several endangered species are extinct in the area (Artemisia scoparia, Helichrysum arenarium, Trifolium striatum).
The vegetation of xerothermic grasslands belongs to an association Carlino acaulis-Brometum erecti (an alliance Bromion erecti). In respect of former land use it is possible to differentiate the vegetation on ancient pastures (with species Helianthemum grandiflorum, Verbascum lychnitis, Festuca ovina) and the vegetation on old fields (with Campanula rapunculoides, Agrimonia eupatoria).
The association Alysso alyssoidis-Sedetum albi (an alliance Alysso alyssoidis-Sedion albi) is widely distributed on poorly developed soils of calcareous rocks. Xerothermic plant communities are highly endangered.
The expansion of shrubbery is the main problem. The degradation of grasslands is caused by the absence of pasture management.