The conditions of tufa formation and their distribution throughout the Dniester River canyon and adjacent territories are studied in the current work. The sites with waterfalls, in which the carbonate Silurian rocks are characterized by horizontal faults with the formation of aquicludes, were allocated. A group of different classes is formed in the zone of water entrainment flowing through the cliff walls. The central place is occupied by Montio-Cardaminetea (Cratoneuretum filicino-commutati), represented by moss cushions of Cratoneurum filicinum, Palustriella commutata, Didymodon tophaceus, which drain water, where CaCO3 is absorbed and powerful tufas are formed. On the surface under falling water, algae of emerald color Stigeoclonietea tenuis (Cladophoretum glomeratae) develop along with the dark spots of cyanobacteria Gloeocapsetea sanguineae (Scytonema myochrous) on slightly moistened rocks. At the base of the waterfalls, the hygrophilic Agrostis stolonifera (Molinio-Arrhenatheretea, comm. Palustriella commutata-Agrostis stolonifera) grows. Such a holistic syntaxa complex (microcombination) consisting of different classes representing different habitats is considered by us as a separate habitat 7220 Petrifying springs with tufa formations (Cratoneurion), and according to the UcrBiotop classification, refers to the waterlogged grassland-type biotopes (D:3.1222). This microcombination is treated as a sigma-association of Cratoneuretum filicino-commutatae sigmetum. In the current work we provide a quantitative threats assessment (class III), sozological value (class II), estimation of the relative cost of habitat loss (63.5% – II class), therefore these biotopes require certain conservation measures.
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