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 highly short of plant diversity and soil science researches in karst rocky desertification ecosystem, and the successions of plant diversity and soil physical-chemical properties are still unclear in the process of rocky desertification, all 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 surrounding, that is, nil, potential, low, middle, and high, in these three experiment areas. Then, the plant diversity and soil physical-chemical properties were surveyed and analyzed by methods of ecological survey, chemical determination, and mathematical statistics. Results show that 1) the vegetation is very simple with extreme low richness in rocky desertification surroundings, and with the increased degree of rocky desertification, the plant diversity appear remarkable change, for example, species is more few, importance value of dominant species is more high, and structure of plant community and ecological niche is more confusion. 2) There are significance differences of soil physical-chemical properties between different degrees of rocky desertification, and there is remarkable correlation between soil physical-chemical properties and plant diversity in rocky desertification ecosystem. 3) Principal component analysis show that the evenness index of plant diversity together with its correlative soil physical-chemical factors can represent the degradation degree of karst ecosystem. Results have important values in the protection of karst forest ecosystem and the control of rocky desertification.