Terrestrial distribution of soil microbial quantity in natural wetland of the Xilin River at Mongolian Plateau

Terrestrial distribution with soil bacteria, fungi and actinomycetes amount of the Xilin River natural wetland was investigated. The result that soil microbial community compositions of typical grasslands and natural wetlands, with the elevation changes gradually reduce the soil moisture content from bed sludge (HX) to typical steppe (DT), changed significantly. The total microbial and aerobic bacteria numbers were gradually increased in order of HX, riparian mire (HB) and low flood plain (DQ). DQ is 2.74 times as aerobic bacteria number as HB and 5.53 times as aerobic bacteria number as HX. The total microbial and aerobic bacteria numbers were gradually decreased in order of DQ, high flood plain (EQ) and DT. DQ is 1.36 times as aerobic bacteria number as EQ and 9.89 times as aerobic bacteria number as DT. The tendency of microbial terrestrial distribution from HX to DT is single peak which appear DQ, indicating that DQ environment is more suitable for growth and reproduction of aerobic bacteria. Spore-forming bacteria and fungi numbers were gradually increased with soil moisture decreasing from HX to DT, in addition, the positive correlations are found between Spore-forming bacteria and fungi numbers and organic matter, total nitrogen, total phosphorus and microbial biomass C contents. Spore-forming bacteria numbers have significant differences between HX, HB and other three samples, and significant differences were found among DQ, EQ, DT. Fungi numbers have significant differences between HX, HB, DQ and EQ, DT, and significant differences were found between EQ and DT. DT included the largest number of actinomycetes and its numbers have significant differences between DT and wetlands.