长江口最大浑浊带潮滩沉积物间隙水营养盐剖面研究  

Profiles of Sediment Porewater Nutrient Concentrations on Tidal Flat of Turbidity Maximum Zone in Changjiang(Yangtze River) Estuary

作　　者：高磊[1] 李道季[1] 王延明[1] 余立华[1] 孔定江[1] 李玫[1] 李云[1] 方涛[1] 

机构地区：[1]华东师范大学河口海岸学国家重点实验室,上海200062

出　　处：《环境科学》2006年第9期1744-1752,共9页Environmental Science

基　　金：国家重点基础研究发展规划(973)项目(2002CB412405;2004CB720505);教育部创新团队基金项目

摘　　要：2005—03～2006—02对长江口崇明东滩高、中、低潮滩3个典型站点沉积物间隙水中各营养盐成分含量及其随深度的变化做了为期1a的逐月观测。结果显示，研究区域间隙水中NH4^＋和SiO3^2-的浓度一般在200～500μmol／l之间，高、中、低潮滩间显示出了不同的分布态势；与高潮滩和中潮滩相比，没有植被覆盖、粒径较粗的低潮滩往往具有较高的NH4^＋浓度和较低的SiO3^2-浓度；SiO3^2-随季节的变化主要受温度的影响，而NH4^＋的变化则较为复杂，较低值往往出现在植物生长旺盛的春、夏季，与NH4^＋和SiO3^2-的浓度相比，NO2^-＋NO3^-和PO4^3-在间隙水中的浓度往往要低2～3个数量级，但由于受到生物扰动等因素的影响，沉积物表层NO2^-＋NO3^-浓度在某些月份可能出现几十μmol／l。的高值，较高的NO2^-＋NO3^-浓度以及沉积物中氧化环境向还原环境的快速转变为显著的反硝化反应的发生提供了物质基础与环境基础，从而可能对生源要素在长江口陆海相互作用地区的生物地球化学行为产生深刻的影响。Profiles of nutrients （i. e. NH4^＋ , NO2^- , NO3^- , PO4^3＋ , and SiO3^2- ） in porewater of sediment were investigated monthly in the intertidal flat of Chongming Dongtan in Changjiang （Yangtze River） estuary during March 2005 to February 2006. The results indicate that concentrations of NH4^＋ and SiO3^2- in porewater are always in the range of 200μmol/L to 500μmol/L and show different patterns of distribution profile among high, middle, and low marshes. Compared to high and middle marsh, low marsh, without vegetation coverage and of coarser grain size, generally contains higher NH4^＋ and lower SiO3^2- concentrations. SiO3^2- concentrations are predominantly determined by seasonal temperature change, but variations of NH4^＋ are more complicated and prone to exhibit lower values in spring and summer when the vegetation above show relatively high growth rate. Concentrations of NO2^- ＋ NO3^- and PO4^3- in porewater are commonly much lower than NH4^＋ and SiO3^2- by 2 to 3 orders of magnitude, however, due to factors such as bioturbation, the concentrations in top sediment may be higher than 10μmol/L. The relatively high NO3^- concentration in top sediment,together with the rapid transfer from oxygenic to anoxic environment, make it possible that significant denitrification happens, which may draw its remarkable influence on the biogeochemical cycles of nutrient elements in the land-sea interaction area in Changjiang （Yangtze River） estuary.

关 键 词：间隙水 营养盐 季节变化 长江口 

分 类 号：X145[环境科学与工程—环境科学]