Mazur I. Ecological assessment of the state of phytocenoses of the marsh biotopes in the Tylihul - Southern Buh interfluve

The thesis presents the results of the ecological assessment of marsh biotopes and phytocenoses of the rivers in the Tylihul-Southern Buh interfluve. The study found that, unlike the delta marshes of the Danube-Dniester interfluve, the marshes of small and medium-sized rivers are the variants of grounds of exceptionally marsh type, which explicitly refer to the group of ground wetland seasonal/intermittent freshwater marshes, river and swamp on the mineral turfless grounds. The areas of typical wetland marshes at the lower reaches of the Southern Bug preserve the primary biodiversity in the best condition. The other marsh areas of the investigated interfluve are significantly (for 50-60%) turned into pastures and fields with degraded vegetation of steppe-meadow, meadow-halophytic, and ruderal type. The total area of the Tylihul-Southern Buh interfluve rivers' marshes is about 15000 hectares. The performed analysis of phytodiversity of marsh biotops has revealed that the reachest biodiversity is inherent to the riverine water vegetation. The plant communities of steppificated and salt marsh meadows with uneven distribution of the corresponding groups of species or with high level of dominance are poor in vegetation. The current catastrophic drying up of streams in the Tylihul-Southern Buh interfluve induces the succession of seral changes, leading to xerophytization, halophytization, and synantropization of marsh vegetation. Accordingly, the present state of the marshes is critical and requires an indispensable protection.