Abstract:

The soil samples were collected in different restoration stage from the study area of the southwestern Guizhou Province. The microbial incubation methods and the biochemical testing were used. The amount of soil microbes, soil biochemical function, soil microbial biomass and soil organic carbon were measured during vegetation succession in the degraded Karst. The results showed that, with degraded Karst vegetation restoration, the amount of bacteria, fungi, antinomies all increased obviously, performing the arboreal community stage>the shrubby community stage>the herbaceous community stage>the bare land stage. Compared with the fungi and antinomies, the bacteria were dominant and the proportion was 95.95%, 93.49%, 92.32% and 92.48% in microbial amount respectively in the four stages. With degraded Karst vegetation restoration, soil biochemical function, including ammonification, nitrification, cellulose decomposition, respiration and nitrogen fixation increased. The change pattern of soil microbial biomass carbon was consistent with microbial amount.There was a significant positive correlation between soil microbial biomass carbon and organic carbon (P<0.01).

Key words: degraded Karst, vegetation restoration, soil microorganisms