中文摘要：

选择三江平原小叶章湿地不同水分带上的两种土壤类型（草甸沼泽土和腐殖质沼泽土）为研究对象,运用模拟土柱的方法,研究了两种土壤中硝态氮和铵态氮的垂直运移规律。结果表明：在水分饱和条件下,两种土壤的硝态氮和铵态氮穿透曲线均符合Gauss单峰模型（R^2≥0.85）,其运移过程主要受粘粒含量的影响;随粘粒含量增加,硝态氮和铵态氮穿透曲线整体上峰值降低,峰面分布变宽,但不同土壤各土层间也存在一定差异,原因与不同土层水分构成、溶质运移方式以及硝化-反硝化作用的差异有关;溶质浓度加倍后,两种土壤0～20 cm土层中硝态氮和铵态氮的穿透曲线也符合Gauss单峰模型（R^2≥0.88）,但其峰值、形状及出流时间均发生不同程度的变化,原因与浓度改变前后土壤水分构成、溶质运移方式的差异有关,铵态氮还与土壤胶体对其吸附饱和程度的差异有关;两种土壤表层的硝态氮和铵态氮垂向迁移能力较强,当湿地水分增加后将不利于有效氮的保持。

英文摘要：

Two typical soils（meadow marsh soil and humus marsh soil）,located in zones different in moisture regime in Calamagrostis angustifolia wetland of Sanjiang Plain,were selected as study objects,and the vertical movement rules of nitrate nitrogen（NO3^--N） and ammonia nitrogen（NH4^＋-N） in them were studied by simulating soil column.Results showed that the breakthrough curves of NO3-N and NH4^＋-N in the two types of soils in saturated condition accorded with Gauss single peak models（R^2≥0.85）,and the vertical movement processes were mainly affected by clay content.As the clay content increased,the peak values and areas of the breakthrough curves,in general,decreased and became wide,respectively.The breakthrough curves of NO3^--N and NH4^＋-N in different layers of the two types of soils also had some differences,which were mainly correlated with the differences of water composition,solute movement pattern and nitrification-denitrification.After the solute concentration doubled,the breakthrough curves of NO3^--N and NH4^＋-N in upper layers（0～20 cm） also accorded with Gauss single peak models（R^2≥0.88）,but the peak values,shapes and outflow times changed due to the differences of water composition,solute movement pattern and NH4^＋-N adsorption saturation.The vertical movement capacity of NO3^--N and NH4^＋-N in upper layers was strong,which was disadvantage to the maintenance of available nitrogen as the increase of wetland water.