三江平原典型沼泽湿地氧化亚氮通量

2002～2004年利用静态箱-气相色谱法对三江平原3种具有代表性的湿地类型(常年积水的毛果苔草沼泽、季节性积水的小叶章湿草甸和常年土壤过湿的灌丛湿地)进行了为期两年半的N₂O现场观测研究.结果表明，三江平原3种类型湿地N₂O通量均有明显的季节变化和年际变化,一般在非冰冻期表现为排放，冰雪覆盖期表现为微弱的吸收.生长季的N₂O通量以灌丛湿地N₂O排放通量最大，毛果苔草沼泽最小.全年平均N₂O交换通量: 毛果苔草沼泽为53.928 mg·m^-2·yr^-1，小叶章湿地为21.408 mg·m^-2·yr^-1，灌丛湿地为657.120 mg·m^-2·yr^-1，证明沼泽湿地是大气N₂O的源.3种类型湿地生长季N₂O通量无明显的日变化，与温度的相关性不大.

N2O flux in typical wetlands of Sanjiang Plain

By the method of static chamber-gas chromatography, this paper studied the nitrous oxide flux in three typical wetlands (perennial waterlogged Carex lasiocarpa marsh, seasonal waterlogged Deyeuzia angustifolia wet meadow, and perennially over-wet brushwood wetland) of Sanjiang Plain from 2002 to 2004. The results showed that the nitrous oxide flux in test wetlands presented obvious seasonal and annual variation, suggesting that these three typical wetlands were all the sources of atmosphere nitrous oxide during plant growth season, and the weak sink in winter. The annual average flux in C. lasiocarpa marsh, D. angustifolia and brushwood wetland was 53.928, 21.408 and 657.120 mg x m(-2) x yr(-1), respectively. No diurnal variation of nitrous oxide flux was observed in three typical wetlands, and there was no significant correlation between nitrous oxide flux and temperature.