中文摘要：

为探索河口区盐淡水湿地潮滩沉积物-水界面无机氮交换通量的空间差异与秋、冬季变化特征及其影响因素,选取闽江河口区内的鳝鱼滩、蝙蝠洲、塔礁洲3个盐淡水差异较为明显的湿地洲滩作为采样断面,对沉积物-水界面无机氮交换通量及其影响因子进行测定与分析,其中3个断面的沉积物与上覆水盐度大小均表现为鳝鱼滩〉蝙蝠洲〉塔礁洲。结果表明：（1）秋、冬季研究区NH＋4-N、NO-3-N和NO-2-N的界面交换通量分别为（-2.174）-1.437mmol/（m2·d）,（-4.113）-0.440mmol/（m2·d）和（-0.152）-0.169mmol/（m2·d）,与国内外一些河口区的研究结果相比处于较低水平;（2）无机氮界面交换通量（除NO-2-N外）存在明显的时空分异特征,从低盐度湿地（塔礁洲）到高盐度湿地（鳝鱼滩）,NH＋4-N界面交换通量秋季表现出由源转化为汇,而冬季则表现为由汇转化为源的特征,鳝鱼滩NH＋4-N的秋、冬季源汇转换表现的最为活跃,NO-3-N的界面交换通量秋季表现为从低盐度湿地到高盐度湿地逐渐减少的特征,而冬季则表现为蝙蝠洲〉塔礁洲〉鳝鱼滩;（3）沉积物盐度与NH＋4-N界面交换通量呈显著负相关（P〈0.01）,与NO-3-N的界面交换通量呈极显著正相关（P〈0.01）;（4）无机氮界面交换通量还受到沉积物粒径、沉积物及上覆水无机氮含量等因素的影响。

英文摘要：

The characteristic of spatial and seasonal variations of inorganic nitrogen exchanges fluxes in sediment-water interface（SWI）was investigated in 3saline-fresh tidal flats of Min River estuary（including Shanyutan,Bianfuzhou,Tajiaozhou）.The inorganic nitrogen exchange fluxes in SWI and main environmental factors were measured in two different seasons of autumn（October in 2012）and winter（January in 2013）.The exchange fluxes of NH＋ 4-N,NO3-N and NO2-N in SWI were（-2.174）~1.437mmol/（m2·d）,（-4.113）~0.440mmol/（m2·d）and（-0.152）~0.169mmol/（m2·d）respectively,lower than some estuarine research results at home and abroad.The exchange fluxes of inorganic nitrogen（excluding NO2-N）in SWI had significant spatial and seasonal patterns.The low salinity wetlands changed from sources to sinks in autumn along the salinity gradient（from Tajiaozhou to Shanyutan）,but changed from sinks to sources in winter.The Shanyutan wetland showed the most significant seasonal source-sink transformation pattern of NH＋ 4-N（from 1.301mmol/（m2·d）in autumn to-1.59mmol/（m2·d）in winter）.The SWI fluxes of NO3-N from low salinity wetlands（Tajiaozhou and Bianfuzhou）were less than the values from high salinity wetland（Shanyutan）in autumn,while it showed the opposite result in winter（BianfuzhouTajiaozhou Shanyutan）.The salinities gradient had a significant negative correlated with the SWI fluxes of NH＋ 4-N（R =-0.634,P0.01）since the adsorption capacity of NH＋ 4 in the sediment decreased with increasing salinity gradient,and the more NH＋ 4 released from the sediment to overlying water.The salinities gradient had a significant positive correlated with the fluxes of NO3-N（R=0.649,P0.01）which implied the sediment denitrification rate might decline with the increase of salinity gradient.That might explain why the low salinity sediment became the effective absorption sink of NO3-N rather than the high salinity sediment（autumn）.The NO3-N fluxes had a significant negative