关键词: 内蒙古, 皇甫川流域, 恢复草地, 退化草地, 土壤微生物, 分布特征

Abstract: The distribution characteristics of soil microbial have been investigated for the recovered grassland and degenerated grassland of Huang Fu-chuan Watershed, Inner Mongolia, China. Soil microbial numbers in both recovered grassland and degenerated grassland are all followed the order: aerobacteria>actinomyces>spore-forming bacteria>fungi; Total microbial numbers in 0~10 cm was more than that in the other soil layers, the vertical distribution of total microbial number was: 0~10 cm>10~20 cm>20~30 cm>30~40 cm>40~50 cm, which decreased along with soil depths. Microfauna was various in different plots. Bacteria's number was the most in all groups, and its variation trend rests with the amount of aerobacteria.;Compared with the degenerated grassland the number of soil microbial groups was higher in the recovered grassland. The number of soil microbial in recovered grassland, such as aerobacteria, spore-forming bacteria, actinomyces and fungi, was higher in autumn than in summer. The distribution characteristics of microbial number in natural grassland related to soil fertility factors, the status of recovered grassland exceeded that of degenerate grassland, so the recovering of grassland is the key measure for improving soil quality and protecting the ecological environment of Huang Fu-chuan Watershed.

Key words: Inner Mongolia, Huang Fu-chuan Watershed, recovered grassland, degenerated grassland, soil microbial, distribution characteristics