温度升高对湿地系统温室气体排放的影响

Impact of global warming on the emission of greenhouse gases in the wetland system

综述了湿地系统温室气体CO_2、CH_4和N_2O的排放机制及温度升高对湿地系统温室气体排放影响的研究进展。温度升高使得湿地植物生长季节延长,促进湿地生态系统生产力的提高,影响湿地生态系统的稳定性。温度升高可改变湿地系统温室气体CO_2、CH_4和N_2O排放的源汇转换,使温室气体排放增加,并对温度变化形成一种正反馈影响。温度升高使得湿地CO_2排放增强,降低湿地土壤碳汇的能力,甚至转变为净碳源。温度升高可增加湿地CH_4排放量,夏季温度升高对CH_4排放通量没有明显影响。温度升高使湿地土壤硝化和反硝化作用增强,促进N_2O的产生与排放,湿地成为N_2O的排放源。同时,温度升高使得湿地水位降低、土壤水分减少,一定程度上约束了温室气体排放增加的强度。并对进一步的研究进行了展望。

Along with the increase of human activities in recent years, the contents of CO2, CH4 and N2O in the atmosphere have been gradually increased and caused the rise of the global temperature. The paper systenmtieally reviewed the emission mechanism of greenhouse gases like CO2, CH4 and N2O in the wetland system. The research of the temperature rise impact on greenhouse gas emission from the wetland system is also discussed as well. The increase of temperature can extend the plant growing season and promote the pro- ductivity of wetland ecosystems, which would significantly impact the wetland ecosystem stability. The global warming could induce the conversion between the sources and sinks of the emitted greenhouse gases CO2, CH4 and N20 and then promote of the greenhouses emission intensity, which would form a positive feedback influence on the global temperature. Temperature rise can enhance the CO2 emission from wetlands and reduce the capability of soil carbon sink, or even transform into a net carbon source. Except the temperature rise in summer season, the temperature rise in other seasons can also in- crease the CH4 emission intensity from the wetlands. Wetland soil ni- trification and denitrification can be promoted by the temperature rise, resulting in the enhancement of N2O generation and emission. At the same time, the temperature rise is able to reduce water level and soil moisture of the wetland, which restrain the increasing intensity of greenhouse gas emission in certain extent. And then the further re- searches are also prospected.