关键词: 土壤微生物, 鄂尔多斯, 沙地, 微生物区系

Abstract: The composition, seasonal variation and characteristics of vertical distribution of soil microorganisms were studied systematically in sand-flowing dune, semi-fixed sand, fixed sand in Erdos, Inner Mongolia. The main results were shown as follows:the soil microbial numbers were obviously varied with the increasing trends of sand dune fixation, that is, fixed sand > semi-fixed sand > sand-flowing dune. The total microbial numbers in fixed sand were 2.8 and 12.5 times as many as those in semifixed sand and in sand-flowing dune, respectively. The bacteria numbers were distributed predominantly in soils of these three kinds of sandy land where they are located (more than 70%), actinomycetes were at second and fungi were the least (under 1%). The seasonal and vertical distributions of soil microorganism were regular in these three sandy sand in the paper. The bacterial numbers in vertical distribution concentrated on soil surface and often reduced with the increasing trends of soil depth, but fungi and actinomycetes numbers concentrated on 1~10 cm soil layer. The seasonal dynamics of distribution of the microorganism numbers were various. The numbers in spring and autumn were much more than those in summer and winter.

Key words: soil microorganism, Erdos, sand, microflora