Karst rocky desertification has been an important ecological issue hindering the economy and society development of South China Karst region, and the control of rocky desertification has been clearly listed in the national projects of economy and society development. But there are short of soil researches in karst rocky desertification ecosystem, and the succession of soil physical-chemical properties is still unclear in the process of rocky desertification, which hardly hinders the control of rocky desertification well work.
Based on these problems, in this study, firstly, three typical rocky desertification regions, that is, Yachi, Hongfenghu, and Huajiang of Guizhou Province, representing three different typical karst landforms of plateau mountain, plateau basin, and plateau gorge, respectively, were selected as experiment areas, and 45 sample plots with area of 20 m × 20 m, respectively, were set up for the 5 typical degrees of rocky desertification, that is, no, potential, low, middle, and high, in these three experimental areas. Then, the soil physical-chemical properties were surveyed and analyzed by the methods of chemical determination and mathematical statistics. Results show that 1) there are obvious differences of soil physical-chemical properties between different degrees of rocky desertification, specifically, bulk density, capillary porosity, total porosity, field moisture capacity, capillary moisture capacity, pH, organic matter content, hydrolysis nitrogen content, available phosphorus content, and total potassium content. But, not as expected, the soil degeneration do not always raise with the increased degree of rocky desertification. In fact, with the increased degree of rocky desertification, the soil degenerate firstly and then improve; 2) Organic matter content, nitrogen content, capillary moisture capacity, bulk density, and porosity all are remarkable correlation with other factors of soil physical-chemical properties, and they are the key factors of soil physical-chemical properties, which have important functions in advancing the soil nutrient cycle and improving the soil physical-chemical properties; 3) Principal component analysis also show that organic matter content, nitrogen content, potassium content, bulk density, moisture capacity, and porosity are the key factors in evaluating the degrees of rocky desertification. Based on these results, the theory, that is, bare rocks have a collected action for soil nutrients in karst rocky desertification ecosystem, was raised, and the response and its mechanism of soil physical-chemical properties to rocky desertification succession was presented. Results have important values in the protection of karst forest ecosystem and the control of rocky desertification.