The Characteristics Of Soil Microbial Community And Its Influencing Factors In Wetland Of Downstream Of Tumen River Basin

The soil microbe is considered as the disintegrator of wetland ecosystem, which not play an important role in material and energy cycle, but also in keeping biodiversity, ecology balance in wetland. When we study the wetland soil microbial characteristics and driving forces, we have to consider the type of wetland, hydrology and wetland plant. So we design two experiment, one is that the relationship among type of wetland, plant community and soil microbe in dominant wetland plant community in lake, swamp and riverine, another is that the relationship among water disturbance, plant community and soil microbe in lacustrine with water disturbance.Results showed that total nitrogen(TN) content ranged from 2.1 g/kg to 2.6 g/kg in swamp, ranged from 1.5 g/kg to 1.7 g/kg in riverine and were significantly different in lacustrine with ranging from 1.2 g/kg t o 3.6 g/kg. The total soil organic matter was lower in riverine than the others. From the low to high disturbance in lacustrine, the TN, SOM and AN were lowest in the middle disturbance region and were highest in C. angustifolia of the low disturbance region. The soil organic matter(SOM) of riverine soil was lower than in the soil of swamp and lacustrine. Based on the soil of high water disturbance, we found that the TN, SOM and available nitrogen(AN) content were in the same level in the soil of Z. latigolia in riverine and E. caudata in lake wetland, the soil microbial taxa ofZ latigolia were greater than in E. caudata. But the TN, SOM and AN content of E. caudata in swamp were greater than in E. caudata in lake wetland, so did the soil microbial taxa. Based on the soil microbe in different plant communities with water disturbance, we use principle component analysis to study the soil microbial community, results showed that the fist component could explain the 92.4% variance, and the second component could explain 3.6% of variance, which showed that the water disturbance is the main driving forces in influencing the soil microbial community. The soil microbe in P. australis, B. pilosa and C. angustifolia is different under the low water disturbance. In total, both of hydrology progress and plant community influence the soil microbial community, especially hydrology progress.Based on the analysis between soil properties and soil microbial structure in different wetland plant communities of lake, swamp and riverine, Redundancy Analysis (RDA) shows that soil AN, TN, SOM and pH could explain the 86% of variance between microbial species and abiotic variables, the soil water content could explain the 8.2% of variance. The study of soil properties and soil microbial structure in lacustrinewith water disturbance, Redundancy Analysis (RDA) shows that soil AN, TN and SOM could explain the 79.5% of variance between microbial species and abiotic variables, the soil water content could explain the 12.3% of variance. Results suggested that wetland types, hydrology progress and plant community are the main factors in driving the soil microbial structure through influencing the AN, TN, SOM, pH and soil water content.