Blystiv V. Formation of hornbeam-beech forest stands in Transcarpathian region, their stability and water-regulating role.

Object of research are hornbeam-beech forests of the Transcarpathian region. The purpose is to identify the processes of formation of hornbeam-beech stands in the Transcarpathian region, to assess their stability and water-regulating functions. Research methods: forest- inventory, soil-hydrological. Scientific novelty: On the basis of comprehensive forestry studies, the processes of disruption of the conditionally even-aged hornbean-beech forest stand with advancing age were elucidated for the first time, it was found that the disruption process for hornbeam-beech forest begins at the age of 130 years, clarified were the peculiarities of formation of young growth under the canopy of conditionally even-aged stands, namely, their lower productivity and lower content of hornbeam, in comparison with young growth on the cutover areas, the development of young stands after the final harvest was investigated, it was established that the spatial structure is characterized by uneven ratio of beech and hornbeam in the area, the relationship was described between type-forming and cultivated species in artificial regeneration, which points to the advantage of natural regeneration of beech and hornbeam in terms of quantity and its competitiveness in growth. Also, the work presents data on stability and potentials of formation of forest stands, the distribution and nature of windfall and snowbreakage in the Transcarpathian region, their features and differences in the Carpathians. Regarding the hydrological role of the forest, the dynamics of water permeability of the soil with the growth of young stands was clarified , the role of different categories of forest cover in the formation of run-off, the influence of forest cover per cent and the structure of forests on water regulation have been determined. Practical significance: The results obtained are the basis for the development of measures for reforestation, care for young stands, and ensuring the stability and protective properties of stands. The results were used in the preparation of "Guidelines for improvement felling in mountain forests of the Carpathians", which were approved by the scientific and technical council of the State Committee of Ukraine and implemented in practice.The materials are also used in forestry practice on the issues of formation of stable hornbeam-beech stands and assessment of their stability. Field of use: forestry.