Response of soil physical and chemical properties to Rocky desertification succession in South China Karst

Three typical karst rocky desertification regions in South China Karst were selected as experiment sites. The succession of karst rocky desertification was divided into five typical degrees: nil, potential, slight, moderate, and severe. Based on the five typical degrees of rocky desertification, sample plots were set up and soil samples were collected to examine the physical and chemical properties. The pattern, dynamics, and change law of soil physical and chemical properties in the succession of karst rocky desertification were studied. The properties of bulk density, capillary porosity, total porosity, field moisture capacity, capillary moisture capacity, pH, organic matter content, hydrolyzed nitrogen content, available phosphorus content, total potassium content, and soil respiration were studied. Results showed that significant differences in soil physical and chemical properties were observed among different degrees of rocky desertification. These properties initially degenerated and then recovered with increased degree of rocky desertification. The soil quality of nil and severe degree of rocky desertification was better than all others. In the succession of soil physical and chemical properties, the key factors were organic matter content, nitrogen content, bulk density, and moisture capacity. Finally, the response mechanism of soil succession was concluded. The results of this study are useful for management of desertified karst ecosystems.