巴音布鲁克高寒湿地夏季CO2和CH4通量日变化研究

Daily characteristics of summer CO_2 and CH_4 fluxes under different water conditions at Bayinbuluke alpine wetland

以天山中部巴音布鲁克天鹅湖高寒湿地为研究区域,采用静态箱-气相色谱法,对处于不同水分条件下高寒湿地CO_2和CH_4排放特征进行研究。结果表明:1)天鹅湖高寒湿地为CO2源,其常年积水区、季节性积水区和常年干燥区CO_2日平均排放通量分别为33.78、66.94、72.06mg·m-2·h-1。常年积水区和季节性积水区为CH_4源,其日平均排放通量分别为714.62、16.82μg·m-2·h-1,而常年干燥区则表现为CH_4的汇,其日平均吸收通量为17.51μg·m-2·h-1。常年积水区CH_4和CO_2日平均通量与季节性积水区和常年干燥区差异性达到极显著水平(P<0.01)。2)湿地CO_2和CH_4通量与表层土壤温度正相关性达到极显著水平(P<0.01),且随着土壤深度的增加土壤温度与湿地CO2和CH4通量的相关性系数有下降趋势。季节性积水区CO_2和CH_4通量与土壤湿度相关性达到显著水平(P<0.05)。湿地CO2和CH4日平均通量分别与活体生物量表现为显著负相关性(r=-0.994)和显著正相关性(r=0.998)。

Taking the alpine wetland at Swan Lake of Bayinbuluke in the middle Tianshan Mountain as a study area,the flux characteristics of CO2 and CH4were measured under different water conditions at alpine wetland ecosystems using the methods of static steel chambers and gas chromatography. The results showed that： 1） Swan Lake wetland is a CO2 source,The average daily fluxes of CO2 in perennial water area,seasonal water area and perennial dry area were 33. 78,66. 94,and 72. 06mg·m^-2·h^-1,respectively. The perennial water area,seasonal water area were CH4 sources,with average daily fluxes of CH4 of 714. 62,16. 82μg·m^-2·h^-1,while the dry area is the storage sink of CH4,the average daily absorption fluxes of CH4 was 17. 51μg·m^-2·h^-1. The difference between the average daily fluxes of CO2 and CH4in perennial water area and the seasonal water area was significant（ P〈0. 01）,and the same to perennial dry area. 2） The fluxes of CO2 and CH4in the wetland ecosystem had a significant correlation with soil temperature（ P〈0. 01）,and with the soil depth increased,the correlation coefficient of soil temperature and CO2 and CH4fluxes decreased. There was a significant correlation between the CO2 and CH4fluxes and soil moisture（ P〈0. 05） in the seasonal water area. There was a significant negative correlation between the average daily fluxes of CO2 and living biomass（ r =- 0. 994）,and a significant positive correlation between the average daily fluxes of CH4 and living biomass（ r = 0. 998）.