Tutova H. The diversity of the soil cover of the natural reserve ‘’Dniprovs’ko – Oril’s’kyy’’

Floodplains are the centers of the species diversity, so floodplain biotopes often contain nature conservation areas. The topical problem of the modern science is the creation of the strategy for the preservation of soils, the functional stability of both individual ecosystems and landscape chains as a whole depends on them. Soil morphology provides the structural and the functional information about floodplain ecosystems. The spatial and the temporal heterogeneity of soil morphology is economically effective ecological indicator that can be easily integrated into the protocols of the rapid estimation for the projects of the of the restoration of the floodplain and the river ecosystem. The aim of the dissertation is to determine the regularities of the variability of the morphology of the structure of soil of the Dnipro-Orylskiy Nature Reserve and to evaluate the role of the diversity of the soil cover as the factor of the structural and the functional stability of the ecosystems of the protected territory. In the process of the realization of the aim, the following tasks have been solved as soil cover has been investigated within the boundaries of the Dnipro-Orylskiy Nature Reserve; the soil map of the reserve has been created based on point data; the classification position of the soils of the Dnipro River valley has been determined (within the Dnipro-Orylskiy Nature Reserve) according to the international WRB classification and the role of Quaternary deposits in the formation of the diversity of the soils of the valley; the species composition of earthworms in the studied ecosystems have been established; the dependence between the aggregate structure and the number of earthworms has been determined. The object of study is the soils and soil biota of the Dnipro-Orylskiy Nature Reserve. The subject of the study is the regularity of the spatial variability of soils of the Dnipro-Orylskiy Nature Reserve and the role of earthworms in the formation of the physical properties of soils. The research has been conducted on the territory of the Dnipro-Orylskiy Nature Reserve, Ukraine. The measurement of the properties of soil has been carried out at 20 polygons, each of which has 105 points placed on the regular grid. The points are located in the center of the squares size by 3x3 meters, within which the relief division has been carried out. The measurement of the resistance of the penetration of soil has been carried out in the field condition with the help of the manual penetrometer Eijkelkamp, to the depth of 100 cm with the interval of 5 cm. The average error of the results of the measurement of the instrument is ±8%. The measurement has been made with the cone with the cross section of 1 cm2. At each point of the measurement of the resistance into the soil has been carried out only in one repetition. The aggregate composition has been determined with the method of dry scattering on the sieve system. The study of the morphology of the soil profile has been investigated in accordance with the recommendations of the field description of soil FAO. The genetic type of the soil profile has been determined according to Rozanov. The soil classification has been carried out according to the working group IUSS WRB. The scientific novelty of the obtained results is the ground cover has been investigated within the boundaries of the Dnipro-Orylskiy Nature Reserve firstly; the classification position of the soils of the Dnipro River valley (within the Dnipro-Orylskiy Nature Reserve) has been determined; the role of Quaternary deposits in the formation of the diversity of the soils of the valley has been found out; the dependence between the aggregate structure and the number of earthworms has been grounded; the information on indicators of the species diversity of the groups of Lumbricidae has been supplemented; the role of the edaphic factors (electrical conductivity, humidity, density, aggregate composition) and the meaning of the vegetation cover on the spatial organization of Lumbricidae have been supplemented; J. Hutchinson's concept of the ecological niche and the methods of their quantitative assessment have been acquired further development. As the result of the dissertation research, the classification position of the soils of the Dnipro River valley (within the Dnipro-Orylskiy Nature Reserve) according to the international classification WRB has been established. The bore pits have been laid along three transects passed through the most significant gradients of the relief within the studied territory. The study of the morphological structure based on 20 soil profiles has showed that the soil cover is closely related to the geomorphological structure of the river valley. The morphological characteristics of the typical soil profiles reflect their structure, the properties, the genesis and determine the classification position according to WRB.