Topological differentiation of the vegetation cover of the Sandomiria Upper Dnister geobotanical district

The article provides distribution patterns of natural vegetation depending on topological conditions and outlines the main directions of its anthropogenic transformation. The boundaries as well as botanical and geographical features of the studied district are specified. The syntaxonomic classification of plant communities is presented. The combinative ecological and coenotic profile was created showing distribution patterns of the main plant communities in relation to changes in the indicator values of ecological factors. Three types of mesocombinations are distinguished: forest, grassland (meadow) and swamp-flood ones. Averaged (relevant) indicator values were calculated based on environmental conditions. It has been established that the forest range is characterized by the indicators close to the background ones, which indicate a high stabilizing role of forest ecosystems. Correlative dependence between changes in indicators of certain factors was found, that enables to predict possible cause-and-effect changes. Under current trends of anthropogenic and climatic changes, a decrease in the humidity regime along with raise in soil pH can be expected in the future, while increase in seasonal changes in moisture will accelerate processes of nitrification and soil mineralization. Some habitats within the district are under significant negative effect of invasive species, e.g. the territory between the Lomnytsia River and Kolomyia town is classified as the one under the highest degree of threats due to huge, probably largest in Ukraine, areas of Heracleum sosnowskyi, Erigeron annuus, Solidago canadensis and Rudbeckia laciniata. In the future, this region may undergo substantial transformation and a special attention is required to protect its biodiversity.