泉州湾海岸湿地沉积物C、N的空间变化

在泉州湾不同类型海岸湿地采集了6根短柱状样,利用激光粒度仪分析了沉积物的粒度并计算了中值粒径,利用元素分析仪分析了沉积物中的总有机碳（TOC）、总无机碳（TIC）和总氮（TN）含量.结果显示,泉州湾海岸湿地的沉积物以粉砂和粘土质粉砂为主,中值粒径介于9.2～18.5 μm之间;水头光滩湿地沉积物TIC含量约为0.137%,高于附近互花米草湿地的含量（0.014%～0.038%）,TIC主要集中在粗颗粒部分.沉积物TOC、TN含量分别介于0.939%～2.057%和0.163%～0.260%之间,互花米草对C、N具有很强的富集能力,红树林对C、N的富集能力很弱;周边的排污活动使水头地区的TOC含量明显高于洛阳江河口地区.沉积物TOC、TN含量与中值粒径之间的相关性很弱,TOC与TN之间具有显著的正相关关系,互花米草湿地TN含量与C/N、互花米草湿地和光滩湿地的TOC与C/N均表现为显著的正相关,这些初步说明泉州湾海岸湿地沉积物的TOC主要来源于周边污染物的排放及植被自身生产.

Spatial Variations of Carbon and Nitrogen in Coastal Wetland Sediments of Quanzhou Bay in China

Six short sediment cores were collected from different coastal wetlands of Quanzhou Bay in order to obtain the particle size distribution and median grain size by laser particle size analyzer, and the contents of total organic carbon (TOC), total nitrogen (TN) and total inorganic carbon (TIC) by element analyzer. Analysis results show that sediment in coastal wetlands of Quanzhou Bay can be classified as silt and clayey-silt, and the median grain size varies from 9.2 microm to 18.5 microm. The TIC content in bare flat sediments of Shuitou area is about 0.137%, which is higher than that in coastal wetland covered by Spartina alterniflora (0.014%-0.038%). TIC content decreases when grain size decreases in these sediments. Contents of TOC and TN vary from 0.939% to 2.057% and from 0.163% to 0.260% respectively. Spartina alterniflora has a strong absorption ability of carbon and nitrogen while mangrove has a weak one, and sewage discharge increases the TOC content in the sediments of Shuitou area which is higher than that of Luoyangjiang River estuary. Weak correlations occur between the contents of TOC and TN and median grain size; a typical strong positive relationship is observed between TOC and TN contents; and significant positive relationships of TN content with C/N ratio in Spartina alterniflora wetland and TOC content with C/N ratio in Spartina alterniflora wetland and bare flat are also observed. All these data indicate that the sources of TOC and TN in the coastal wetland sediments of Quanzhou Bay originate from sewage discharge and biogenic production.