Soil microbial activities during regeneration of the degraded karst vegetation -- A case study at Huajiang, Guizhou

The regeneration mechanism of the degraded karst vegetation has been the research focus of soil science and ecology in China for the last decade. The amount of soil microbes, soil biochemical function and soil microbial biomass are analyzed during restoration of the degraded karst vegetation and the change of soil microbial activities was studied on ecological synthesis control demonstrated area in Huajiang karst plateau, Guizhou. The results showed that,with degraded karst vegetation restoration, the amount of bacteria, fungi, antinomies and total microbial amount ascend obviously, performing bare land stag〉herbaceous community stag 〉shrubby community stag 〉 arboreal community stag. Compared with the fungi and antinomies, the bacterium is dominant and the proportion is 95. 95%, 93. 49%, 92. 32% and 92. 48% in microbial amount. The amount of major physiological group are increasing, ammoniating bacteria〉nitrifying bacteria 〉cellulose decomposing microbes〉 nitrogen-fixing bacteria. Soil biochemical function, including ammonification, nitrification, cellulose decomposition, respiration and nitrogen fixation are increasing. The soil microbial biomass C ascended significantly. There is a significant positive relationship between soil microbial biomass C and organic C （P〈0.01）. Soil microbes are recommended as one of major characteristics of soil quality during degraded karst vegetation restoration. It reflects that soil quality is restoring gradually with degraded karst vegetation succession.