关键词: 沙质草地, 牧后恢复, 土壤性状, 科尔沁沙地

Abstract: The characteristics of soil physical, chemical and biological properties of sandy grassland in natural restoring processes after different grazing intensity disturbance were studied. Contents of organic carbon, total nitrogen and phosphorus, available nitrogen and phosphorus, and basal soil respiration in topsoil among different treatments have significant differences: post-moderate-grazing restoration plot > post-light-grazing restoration plot > non-restoration plot > post-heavy-grazing restoration plot. Soils in post-heavy-grazing restoration plot exhibit higher bulk density and pH values, and lower Catalase, Urease, and alkaline Phosphatase activities compared to other plots. Soil nutrients and enzymes in sandy grassland concentrate in the upper layer of the profile and decrease with depth. The effects of grazing livestock on soil properties occurred in the 0~7.5 cm soil layer. Heavy grazing has overtaken the threshold of sandy grassland's carry capacity and the threshold of resistance to disturbance, which worsens soil properties and weakens resilience. However, moderate grazing enhances the cycling of soil nutrient materials and favors the maintenance and improvement of soil fertility and soil resilience.

Key words: sandy grassland, post-grazing restoration, soil properties, Horqin Sandy Land