The influence of deluvial processes on macro- and micromorphology of ravined forest soil

The paper presents the results of studying the effect of deluvial processes on the formation of macro- and micromorphological properties of forest soils on the example of ravined biogeocenoses of Dnieper Prysamarya. Ravined forest biogeocenoses have a long history of development associated with the evolution of land cover in Postpleistocene epoch. One of the factors of soil formation in ravines is deluvial process as a natural phenomenon typical for the landscapes of the present steppes. Ravined forest soils in the catena in the upper reaches of the ravine Glyboky have been studied. They are situated on the upland part of the watershed-gulch landscape in 2 km tonorth of the Andreevka village Novomoskovsk district Dnepropetrovsk region. The methods of macromorphological and micromorphological study of genetic profiles of soils have been used. It is established that ravined forest ecosystems are subjected to intensive influence of deluvial processes, whereby, morphogenesis of ravined soil has a complex peculiar character, which results to theformation of specific morphological properties. It is revealed that the source rock for the forest chernozem on the slopes and formeadow-forest soils of the thalweg are loamy humus deluvial deposits, unlike the ordinary chernozem near the ravines formed on loess rocks. Modern deluvial deposits are the materialof surface horizons of chernozems adjacent to ravine territories. Ravines act as storage ofhumus material of steppe chernozem rendered by adjacent areas. The peculiarities of the morphological structure of the profiles of the soils indicate the intensity of involvement of deluvial material in the processes forest chernozem formation. The different effects of slope processes on the structure of the investigated soil catenahave been revealed. Ordinary chernozem near forest edges have signs of erosion of the surface horizons, while the forest soils of slopes and thalweg are characterized by superpower profile. It is found that the profile of the thalweg and forest soils tends to develop, increasing its power in the two lateral directions: down – thanks to the vertical flow of substances (lessivage, intensive movement of soil invertebrates, the development of the root system); up – the deposition of lessivage material. Deluvial processes connected with lessivage ones as theytransport the new mass of finely divided material into the body of forest soil.