Rare shady chasmophytic habitat communities (8210) in Ukraine

Abstract The characteristics of shaded chasmophytic habitats on calcareous rocks in forest conditions are described, where the forest canopy primarily acts as a shading factor that determines microclimate, humidity and light levels. These communities can be found in deciduous forests of the Carpinion betuli, Fagion sylvaticae and Tilio-Acerion alliances, where they are confined to steep calcareous rock faces and cliffs. Syntaxonomically, these communities belong to the Polypodietea class (Ctenidio-Polypodietalia vulgaris order, Ctenidio-Polypodion vulgaris alliance) and to four informal communities: Isothecium alopecuroides-Polystichum braunii, Porella platyphylla-Asplenium ruta-muraria, Pseudanomodon attenuatus-Chrysosplenium alternifolium and Pedinophyllum interruptum-Polystichum aculeatum. We evaluated indices of environmental parameters according to the synphytoindication method using Didukh’s scales. An assessment of the threat impacts and indicators of sociological significance shows that the habitat belongs to a rare type (II class), and therefore requires specific conservation measures.