三江平原小叶章湿地开垦前后N_2O通量特征与影响因素分析  

N_2O FLUX CHARACTERISTICS AND ITS AFFECTING FACTORS BEFORE AND AFTER RECLAMATION OF CALAMAGROSTIS ANGUSTIFOLIA WETHAND IN SANJIANG PLAIN

作　　者：孙志高[1] 刘景双[1] 王金达[1] 杨继松[2] 

机构地区：[1]中国科学院东北地理与农业生态研究所 [2]沈阳大学,辽宁沈阳110044

出　　处：《山东农业大学学报（自然科学版）》2007年第3期443-449,456,共8页Journal of Shandong Agricultural University：Natural Science Edition

基　　金：国家自然科学基金项目(90211003);中国科学院知识创新工程重要方向项目(KZCX3-SW-332)资助

摘　　要：利用静态箱-气相色谱法对三江平原小叶章湿地开垦前后N2O的排放通量进行了原位测定,分析了N2O通量特征及其与温度、水分等环境因子的关系。结果表明,典型草甸小叶章湿地和沼泽化草甸小叶章湿地的N2O通量均呈脉冲式排放特征,通量范围分别为0.005-0.111和0.005-0.106 mg.m^-2.h^-1,均值为0.059和0.039 mg.m^-2.h^-1;7月前二者的通量差异主要与冻层融通有关,7-8月主要与降水少及蒸发旺盛有关,9月主要与土壤中丰富的氮素有关;前者的N2O通量与5 cm地温呈显著正相关（p〈0.01）,后者与之相关性并不明显;大豆田和水稻田的N2O通量基本上均表现为排放,通量范围分别为-0.008-0.071和-0.019-0.054 mg.m^-2.h^-1,均值为0.028和0.015 mg.m^-2.h^-1;大豆成熟前的N2O通量与5 cm地温呈显著正相关（p〈0.05）,之后取决于土壤中丰富的氮素;水稻成熟前较低的积水水位和土壤pH是导致N2O通量较高的重要原因,之后较高的通量主要与稻田排水有关。估算结果表明,两种小叶章湿地的N2O排放量分别为196.42和136.98mg N2O.m^-2,大豆田和水稻田分别为84.86和70.22 mg N2O.m^-2。说明湿地开垦后,耕地利用的“重用轻养”方式会导致N2O排放量的明显降低。该方式虽然会降低N2O排放量,但对粮食生产影响较大。N2O emission fluxes before and after reclamation of Calamagrostis angustifolia wetland in Sanjiang Plain were observed in situ with static -chamber and GC methods. The N2O flux characteristics and relationships between fluxes and environmental factors, such as temperatures, moistures etc, were also analyzed. The results showed that the N2O fluxes of typical meadow C. angustifolia wetland （TMCW） and marsh meadow C. angustifolia wetland （MMCW） all presented pulse emission characteristics. The ranges of fluxes were 0.005 -0.111 and 0. 005 -0. 106 mg · m^-2 · h^-1, and the means were 0. 059 and 0.039 mg· m^-2 · h^-1 , respectively. The differences of their fluxes before July were mainly correlated with the thaw of frozen layers. Between July and August, the fluxes were mainly correlated with little precipitation and higher evaporation, and in September, they were mainly depended on available nitrogen content in soil. Further analysis indicated that the N2O fluxes of TMCW had significantly positive correlation with 5 cm ground temperature （p 〈 0.01 ） , but the correlation of MMCW was not evident. The N2O fluxes of soybean field and paddy field, on the whole, all presented emission characteristics. The ranges of their fluxes were - 0.008 - 0.071 and - 0. 019 - 0. 054 mg · m^- 2 · h^-1, and the means were 0. 028 and 0. 015 mg·m^-2 · h^-1, respectively. Further analysis indicated that the N2O flux of soybean field had significantly positive correlation with 5cm ground temperature （p 〈0.05 ）before mature. After that, it was mainly depended on the abundant nitrogen in soil. The lower hydrous level and soil pH were the main reasons that caused higher N2O flux of paddy field before mature. After that, its higher N2O fluxes were mainly correlated with the drainage of paddy field. The estimation results showed that the emission amounts of TMCW and MMCW were 196.31 and 136.45 mg N2O m^-2, and the values of soybean field and paddy field were 84.86 and 70.22 mg N2O m^-2, respectively. These results ind

关 键 词：N2O通量 开垦 小叶章 湿地 三江平原 

分 类 号：X171.4[环境科学与工程—环境科学]