The thesis is devoted to bryophytes in forest plant communities of the Carpathian part of the Dniester River basin. According to obtained data, 227 species of mosses have been identified for the forest communities of the Carpathian part of the Dniester River basin (49 liverworts among them). The bryological content of the floristic composition of forest plant communities belonging to 13 different floristic associations has been revealed. Mosses in forest communities of associations from class QUERCO-FAGETEA (Dentario glandulosae-Fagetum, Stellario holosteae-Carpinetum betuli, Luzulo luzuloidis-Fagetum, Alnetum incanae, Ficario-Ulmetum minoris, Lunario-Aceretum pseudoplatani) were investigated. The bryocomponent of the forests of the associations Betulo pendulae-Quercetum roboris (class QUERCETEA ROBORI-ETRAEAE) and Frangulo-Rubetum plicati (class RHAMNO-PRUNETEA) were studied. Coniferous forests belonging to the class VACCINIO-PICEETEA were studied. Lists of bryophytes for the associations Abietetum polonicum, Pino cembrae-Piceetum, Pinetum mugo carpaticum, Bazzanio-Piceetum Abieti-Picetum (montanum) have been determined. It was found that the highest species diversity is characteristic of the Abieti-Picetum montanum) association. The species list of the coniferous forest associations of the Piceion abietis alliance differs most in composition from the bryoflora of mixed and deciduous forest associations. It was determined that in most forest associations heliosciophytes and mesophytes (in terms of light and humidity) predominate. Coenopopulations of seventeen species of mosses with different status of rarity were found in the forests of the Carpathian part of the Dniester River basin. This list includes regionally rare species, species from the Red Data Book of Eropean Bryophytes and one species from the Red Book of Ukraine. All these species can be considered as indicators of the level of autochthony of forest communities. Representatives of mosses have been identified, which may be indicators of forest integrity at the regional level, sustainability of ecological conditions of plant communities. Research has shown that the bryocomponent of old-growth forests is richer. Many species have been identified that did not occur in the secondary forests of the region. These species of mosses (Metzgeria conjugata, Tritomaria exsecta, Antitrichia curtipendula, Neckera pumilla, Hypnum vaucheri, Cirriphyllum crassinervium, Anomodon viticulosus, Polytrichastrum pallidisetum, Campylostelium saxicola) can be indicators of the autochthony of forest cover. Biocoenotic connections between mosses and ornithofauna, which use moss in nest building, were identified. 49 species of mosses were found in the nests of 7 birds species (Turdus philomelos, Turdus merula, Turdus pilaris, Prunella modularis, Fringilla coelebs, Chloris chloris, Lanius collurio). The thesis develops the recommendations on a monitoring and conservation of coenopopulations of mosses and forest communities.
