Yakovyshyn V. Erosion resistance of beech-fir ecosystems of Bukovyna Precarpathians.

Thesis deals with the erosion resistance of beech-fir plantations of Bukovyna part of Precarpathians. The conditions of formation of erosion risk in the research region have been analyzed. The influence of forest stands of different age, composition, location on a slope on properties of forest soils and their erosion resistance have been researched. Low level of exchange cations in soils of studied region indicates poor water-physical, physics-chemical properties of these soils and potential for development of erosion processes. It is found that forest plantations form soils with high water-resistant properties increase, due to existing structure, high content of humic particles and the presence of micro roots that penetrate and bind the soil. The influence of forest ecosystems in forming of forest environment is ascertained, including: forest litter accumulation, changes in hardness and permeability of the soil, spreading root systems. Indicators of forest-mensuration indices of beech-fir plantations are defined and especially their growth in context of strengthening their protective functions. Peculiarities of snow accumulation, freezing soil under the canopy and in open areas to determine the overall meliorative impact of forests in combating formation of surface runoff has been researched.