植物对沼泽湿地生态系统CO_2和CH_4排放的影响

Influence of Plants on CO_2 and CH_4 Emission in Wetland Ecosystem

利用静态暗箱／气相色谱法于2003～2005年在生长季对三江平原小叶章（Calamagrostis angustifolia）沼泽化草甸和毛果苔草（Carexlasiocarpa）沼泽地区CO2和CH4的排放通量进行野外对比观测实验。结果表明：2003-2005年生长季小叶章草甸土壤-植物系统C02排放通量分别是土壤C02排放通量的1．65、2．06和2．01倍，毛果苔草沼泽土壤-植物系统CO2排放通量分别是土壤CO2排放通量的2．58、2．27和4．21倍，表明沼泽湿地土壤-植物系统CO2排放通量的主要贡献者是植物地上部分的呼吸作用，且3个生长季小叶章草甸CO2排放通量均显著大于毛果苔草沼泽，主要是由于植物生物量的差异以及土壤微生物活性的不同。2003～2005年植物生长季，小叶章草甸土壤-植物系统CH4排放通量分别是土壤的4．84、3．55和6．45倍，毛果苔草沼泽土壤-植物系统CH4排放通量分别是土壤的2．60、1．25和3．22倍，且3个生长季小叶章草甸和毛果苔草沼泽CH4排放通量均具有显著差异，这主要是由于水位的差异以及植物对CH4排放能力的不同造成的。

CO2 and CH4 fluxes were measured by closed opaque chamber and gas chromatography system. The experiment was carried during 2003~2005 growing seasons in field. The results showed that CO2 e- mission flux from soil-plant system were 1.65,2.06,2.01 times as high as that from soil in Calarnagrostis angustifolia meadow during three growing seasons, while 2, 58, 2. 27,4. 21 times in Carex lasiocarpa marsh. The main contributor of CO2 emission flux of wetland soil-plant system was the respiration of wet- land plants aboveground. The CO2 emission flux of Calarnagrostis angustifolia meadow was higher than that of Carex lasiocarpa marsh significantly. The differences of the plant biomass and of soil microbial ac- tivity between the two wetlands could explain this phenomenon. With the plants participation,the CH4 e- missions ability was enhanced greatly. CH4 flux of soil-plant system were 4.84,3.55,6.45 times as high as that of soil in Calarnagrostis angustifolia meadow during three growing seasons, while 2.60,1.25,3.22 times respectively in Carex lasiocarpa marsh. There was obvious difference in CH4 emission flux between Calarnagrostis angustifolia meadow and Care：r lasiocarpa marsh during three growing seasons. This was because the difference of water level and the difference of the abilities of plant emitting CH4 between the two wetland species was another reason.