[Dynamics of CO2 and CH4 concentration in the mire soil and its impact factors].

The wetland plays a important role in global carbon cycling in terrestrial ecosystem, the greenhouse gas emission in the mire, especially the CO2 and CH4 level, show distinctly spatial and temporal variation. The product and emission of the CO2 and CH4 are related to soil organic carbon (SOC), dissolved organic carbon (DOC) and nitrogen content, meanwhile which are affected by the soil temperature and hydrological condition. The concentration of CO2 and CH4 are high in mire soil in the Sanjiang plain, especial at the root layer (10-35cm). From the middle of September to October, the aboveground of plant came into die, but the CO2 and CH4 level increase significantly in mire soil, and show significantly positive relationship between them. The ecosystem respiration and the soil respiration affected the methane emission distinctly, also with the significantly positive relationship.