南极苔原近地面CO_2、CH_4、N_2O浓度和通量的相互关系

在南极苔原 ,首次系统地研究了近地面CO2 、CH4、N2 O浓度及通量的相互关系 ,结果表明 :天气条件对三种温室气体浓度日变化影响较大 ;在天气较晴稳及雪天条件下 ,CO2 与CH4、N2 O浓度日变化存在明显的消长关系 ;而在雨天这三种气体浓度日变化趋势基本一致 ;整个夏季CO2 与CH4浓度变化趋势基本一致 ,而N2 O却与二者浓度的变化趋势相反 ;另外 ,在雨、雪天气条件下CH4、N2 O通量日变化存在消长关系 ,整个夏季二者的通量变化也存在明显的消长关系 ;南极苔原土壤对CH4主要起着汇的作用 ,对N2 O主要起着源的作用 .此外 ,CO2 浓度变化对苔原CH4通量有较大影响 ,CO2 浓度增加会适当减缓CH4汇的作用 ,甚至使南极苔原由CH4的汇变为源

Relationships between CO_2, CH_4 and N_2O Concentrations and Fluxes in Antarctic Tundra

Relationships between CO 2, CH 4 and N 2O concentrations and fluxes in Antarctic tundra were studied systematically under natural conditions of Antarctica. The results show that weather conditions had an important effect on daily variations of the three greenhouse gases' concentrations. Daily variations of their concentrations appeared negatively correlative relationships on clear or snowy days while they were consistent on rainy days. Seasonal variations of CO 2 and CH 4 concentrations were consistent in the austral summer, but N 2O concentrations were inconsistent with them. Daily and seasonal variations of CH 4 and N 2O fluxes appeared negatively correlative, and Antarctic tundra soils mainly acted as sinks for CH 4 and sources for N 2O. In addition, variations of CO 2 concentrations had a certain effect on CH 4 fluxes from tundra soils, and elevated CO 2 concentration can decrease the sinks for CH 4 and even convert them into the sources.