三江平原小叶章湿草甸CH_4地-气交换特征  

Characteristics of methane exchange between Deyeuxia angustifolia wet meadow and atmosphere in the Sanjiang Plain.

作　　者：王毅勇[1,2] 宋长春 郑循华[1] 王德宣[1] 闫百兴[1] 赵志春[1] 娄彦景[1] 

机构地区：[1]中国科学院东北地理与农业生态研究所 [2]中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室

出　　处：《农村生态环境》2004年第3期1-5,共5页Rural Eco-Environment

基　　金：中国科学院知识创新工程重大项目(KZCX1-SW-01-06);国家自然科学基金项目(40331014);中国科学院东北地理与农业生态研究所学科前沿领域项目(KZCX3-SW-NA-03)

摘　　要：用密闭不透明箱-气相色谱法对三江平原小叶章湿草甸进行了为期2a的现场观测研究。结果表明:三江平原季节性积水的小叶章湿草甸全年CH4排放呈明显的双峰型变化。在非冰冻期(5月至10月)CH4排放通量为0.297～18.914mg·m-2·h-1,排放峰值出现在6月和8月、9月;冰冻期(11月至次年4月)CH4排放通量为0.048～2.921mg·m-2·h-1,排放低值出现在冬季的12月至次年3月之间,以及发生季节性干旱的7月。冰雪覆盖下的小叶章湿地依然有CH4排放,冰冻期CH4排放量约占全年排放总量的4.94%。在季节性积水或过湿的环境中,小叶章湿草甸CH4排放通量的季节变化主要由温度和土壤水分条件共同控制,其日变化特征表现为白天排放通量大,夜间则小。The Sanjiang Plain is the largest marsh-wetland concentrated region in China.Located in the northeast of Heilongjiang Province,the Plain has a total marsh-wetland area of about 83.5×10~4 hm^2 with rich carbon resources.Numerous rivers crisscrossing and lakes dotting this region forming vast tracts of flood plain.The study was carried out at the Ecological Experimental Station of Mire-Wetland in the Sanjiang Plain,Chinese Academy of Sciences(47°35′N,133°31′E;56 m above sea level)at the center of the Sanjiang Plain. In the region the mean annual precipitation is 550～600 mm and the annual mean temperature is 1.9 ℃.Its vegetation is mainly composed of marshes and wet meadows,and its soils are marsh soil,meadow soil and peat soil.For the study a typical type of seasonal waterlogged Deyeuxia angustifolia wet meadow was selected.The methane fluxes were measured by a closed stainless steel chamber and gas chromatography(Agilent 4890)system.The experiment lasted from June 2002 to May 2004,measuring methane fluxes twice a week,and monitoring diurnal change of the flux once a month,with three duplicates at each sample site.Meanwhile,the air temperature inside and outside the chamber, and soil temperature at the surface and 5 cm depth were also measured at the same time.The results show:there is an obviously seasonal variation and uncertain variation of the methane emission from the seasonal waterlogged Deyeuxia angustifolia wet meadow,and the methane flux was controlled by water and temperature.Two methane flux peaks appear in a year, one is in June and the other is in August or September. The methane flux from the Deyeuxia angustifolia wet meadow is averaged 0.297～18.914 mg·m^(-2)·h^(-1) in the non-frozen season(from May to October),and the methane emission from the Deyeuxia angustifolia wet meadow could still be detected,but much lower in flux during the frozen season(from November to April)in the Sanjiang Plain,accounting for 4.94 percent of the total of a year,which is about 0.048～2.921 mg·m^(-2)·h^(

关 键 词：三江平原 小叶章湿草甸 CH4排放 密闭不透明箱-气相色谱法 

分 类 号：X16[环境科学与工程—环境科学] X144