沼泽湿地生态系统土壤CO2和CH4排放动态及影响因素

湿地在全球陆地生态系统碳循环中具有重要的作用,沼泽湿地温室气体排放特别是CO₂和CH₄排放具有明显的时空变化特征.沼泽湿地CO₂和CH₄的产生和排放与土壤有机碳、溶解有机碳及氮素含量有密切关系,同时受土壤温度和水文条件的影响.三江平原沼泽湿地土壤中CO₂和CH₄具有较高的浓度值,浓集中心位于植物根层(10～35cm), 9月下旬到10月中旬沼泽湿地植物地上部分枯死后,土壤中CH₄和CO₂浓度有阶段性增加的趋势,且土壤中CO₂与CH₄间呈显著正相关关系.沼泽湿地生态系统呼吸及土壤呼吸对CH₄排放通量也有较大的影响,二者间呈显著正相关关系.

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.