RESEARCH OF EROSION-PREVENTIVE ROLE OF FOREST STRIPS ON SLOPES

Purpose: to investigate the erosion-preventive role of forest strips on the slopes. Methods: artificial sprinkling on landscape profiles. Results: the positive influence of forest belts (Rostov region) on the humus content and other properties of the upper layer of ordinary chernozems, as well as on the formation of surface runoff and the erosion occurrence was determined. When moving off from a single forest strip (height H, m) down the slope, the humus content in the upper soil layer decreases linearly, the water-physical properties of soils (density and porosity) change according to logarithmic dependencies. This ensures the surface runoff regulation near the forest strip and increase of runoff and erosion moving off it (30 H or more). The distribution of humus, water-resistant aggregates, density and porosity in a soil layer of 0–20 cm on a slope section between forest strips is characterized by polynomial equations. This reflects the following picture: a change in runoff is characterized by a third-order polynomial, and soil erosion is a fourth-order one (absence of runoff and erosion near the watershed divide and ravine forest strips and their increase towards the center of the field). The positive impact of the watershed dividing forest strip extends 30–40 H down the slope, and the ravine forest strip 15–20 H up the slope. On the slope without forest strips, no significant changes in humus, water-resistant aggregates, and water-physical properties were noted. In this case the conditions for the surface runoff formation and the soil erosion occurrence may vary due to soil erosion. Conclusions: the erosion-preventive impact of a single forest strip down the slope gradually decreases according to the logarithmic dependences, completely disappearing at a distance of 30 H or more. Forest belts adjacent to the slope provide their erosion-preventive effect on the space between strips (60 H) which is characterized by polynomial equations.