Rastlinné spoločenstvá pod skalnými prevismi vo Veľkej Fatre

The first (both for Czechoslovakia and the West Carpathians) floristic and syntaxonomical evaluation of unique types of the nitrophilous communities under overhanging calcareous cliffs in the Velká Fatra Mts. is presented. Within the alliance Erysimo wittmanii-Hackelion deflexae 7 associations are recognized. They differ from the surrounding vegetation by the high proportion of therophytes and biennial hemicryptophytes. The floristic composition depends on the rock structure, influence of the microrelief, orientation, shape and size of the overhanging cliff as well as on the extreme edaphic and microclimatic conditions. The presence of the species Sisymbrium austriacum, Arabis nova and the natural occurence of Chenopodium foliosum in Slovakia are strictly confined to the communities of the above mentioned alliance.