The Study Of Soil Microbial Activity In Nature Wetland Of Xilin River

It is an important indicator to characterize soil microbial acticity which is the number, biomass and respiration rate of soil microbe. The main purpose is to explore the response mechanism of soil microbe for wetland environmental change, by studying the variation of the number, biomass and respiration rate of soil microorganism in natural wetland of Xinlin River, clarifying the land distribution characteristics of soil microorganism in natural river wetland and its activity, and analyzing the main factors which affect microbial distribution.The results show that the number of soil bacteria presents unimodal distribution, the effects of basal respiration and induced respiration also present peak value in the wetlands of the lower flood plain and the high flood plain with the land distribution of river wetland from the middle of river to the direction of grassland, but the number of epiphyte, ray fungi, bacillus and microbial biomass presents gradually increasing trend. Regression analysis showes that the number of bacillus and epiphyte is correlated with Microbial biomass C content.The control plots of the high flood plain and grassland are significantly higher than the river sediment, which is shown by the quantity and diversity index of filamentous microbial Actinomycetes.Soil respiration shows stronger in the lower flood plain and the high flood plain wetlands, but relatively weak in the river sediment and the typical grassland, which reflects that the flood plain wetland has high microbial activity, it is dovetailed with the high levels of plant productivity. The microbial activity is relatively lower in the aquatic environment of the river sediment and the terrestial enviornment of the typical grassland. It shows that the wet environments of the river sediment and the lower flood plain is more stable which is presented by the lower respiratory quotient of soil microorganism, and shows that microorganism affects a certain degree of stress influence which is indicated by the higher microbial respiratory quotient of the river sand, the high flood plain and the typical grassland.