ИСТИНА

Karst landscapes are widely spread all over the world and some of them are negatively impacted by human activities such as agriculture, mining, industry and so on. For successful management, conservation of karst landscapes and estimation of human impact on such fragile ecosystem it is important to study components of these landscapes in nature reserves. The problem addressed in our work is related to the research of soil catenas on the slopes of subsidence sinkholes in natural reserves. It is based on field research of 24 soil catenas in the north and south of taiga zone, broad-lived forest and steppe zone in European Russia. Our work is devoted to the comprehensive analyzes of soil formation on the slopes, changes in morphological, physical and chemical soil properties from top to bottom of sinkholes and the assessment of contrast among soils within soil catenas. We studied soil erosion within the slopes of sinkholes beneath the forest and steppe vegetation by the method of magnetic tracer. The main feature of soil cover in karst landscapes is a considerable variety of soils within relatively small areas and their high complexity. Soil development in these landscapes is affected by an ancient and modern denudation processes. Current research showed that the thickness of humus horizon increases and the content of organic matter decreases from top to bottom of sinkhole slope. Textural metamorphic and calcic horizons lose their morphological properties such as structure and texture from top to bottom of sinkhole slope. Soils from the bottom of the slopes have more in common rather than soils from the top of the slopes regardless of landscape and morphological properties of sinkholes. Soils in sandy soil catenas are more contrast among each other than soils in loamy and clay soil catenas. Water-filled sinkholes bottoms lead to the increased soil contrast within soil catena in comparison with other sinkholes.