The Influence of Clearcut Logging on the Forest Growth Properties of Soils of Bratsk District of Irkutsk Oblast

The article is dedicated to the results of studies on the evaluation of the effect of clearcut logging on the forest growth properties of soils in the Bratsk District of Irkutsk Oblast. We found that the dynamics of changes in the physical and chemical properties of soils on the logged areas is negligible, while the soils of the control plot differ in properties from disturbed soils. The soil after deforestation can be considered anthropogenically transformed in the upper horizons; the intrasoil horizons have not been changed. In general, the disturbance of the soil cover occurs mainly in the upper horizons. We found that clearcut logging changes the forest growing characteristics of soils. In this case, the upper soil horizon is enriched with accessible forms of elements of mineral nutrition of plants; the acidity of soil, the content of organic matter and the moisture content decrease; the proportion of herbaceous plants and their species composition increase; the productivity of the herbaceous layer grows. Soils at logged areas that have no vegetation and topsoil are subject to erosion processes - deflation, linear erosion (formation of ravines), sheet flood erosion. Consequently, measures for reforestation are advisable.