Trends of Soil Processes in Natural Landscapes of Mountain and Piedmont Provinces of Dagestan

Resumo

Data of long-term researches for revealing the trend of modern processes of soil formation and degradation in the mountain and piedmont provinces of Dagestan are given. The aim of the researches was to study the modern soil-erosion and ecologic-ameliorative status of the soil cover and changes in the naturalresource potential of slope lands under the effect of natural and anthropogenic factors over a 50-year period. A strong effect of exogenic and endogenic factors on slope ecosystems results in development of erosion and degradation processes. The soil cover is formed under conditions of intensive geomorphologic, geochemical, and biological processes. The increasing anthropogenic load and climate aridization exert a strong effect on their dynamics. The comparison of data of earlier soil-erosion survey with modern ones shows great changes in the spatial pattern of eroded soils. The areas of noneroded lands became two times smaller over the period of studies. There is a tendency for a decrease in the areas of brown forest soils of a hydromorphic type of soil formation and for enlargement in the area of semihydromorphic and automorphic brown and chestnut soils. A great diversity of soil–plant cover in the areas with vertical zonality is related to differences in slope aspects, topography, and steepness. Soil evolution is characterized by a trend from hydromorphic and semihydromorphic to automorphic stages of soil formation.