中文摘要：

南大港湿地是北方半人工的滨海沼泽湿地,具有重要的经济价值和生态价值。研究其冬季结冰期及融冰后的浮游生物群落结构的特征,对于了解其水生生态系统的变化有重要意义。2016年1月5日和3月13日河北南大港湿地两次采样的各站位浮游植物样品鉴定结果表明：该湿地浮游植物为硅藻-绿藻型,共鉴定出浮游植物7门,74属,108种。1月结冰期细胞密度范围为（0.26-6.70）×10^7/L,均值为2.25×10^7/L,主要优势种包括衣藻（Chlamydomonas sp.）、小环藻（Cyclotella sp.）以及细小平裂藻（Merismopedia minima）。3月份融冰后细胞密度范围为（0.35-16.35）×10^7/L,均值为4.28×10^7/L,主要优势种包括小球藻（Chlorella sp.）、细小平裂藻（Merismopedia minima）、四鞭藻（Carteria sp.）以及针形纤维藻（Ankistrodesmus acicularis）。结冰期前后,浮游植物资源均较为丰富,结构也比较稳定,但融冰后生物多样性要优于结冰期。由于环境因子空间异质性很大,因此同时期湿地内部各个站位物种种类空间分布和细胞密度差异较大。

英文摘要：

Two cruises were carried out in Nandagang wetland in 5th January and 13th March of 2016. Phytoplankton samples were analyzed and 108 taxa belonging to 74 genus of 7 classes were identified. In January, the cell abundance of phytoplankton ranged （0.26 - 6.70） × 10^7/L,the average abundance was 2.25 × 10^7/L. The dominant species were Chlamydomonas sp. ,Cyclotella sp. ,Merismopedia minima,Kirchneriella sp. and Carteria sp. In March, the cell abundance of phytoplankton ranged （0.35 - 16.35）× 10^7/L, the average abundance was 4.28× 10^7/L. The dominant species were Chlorella sp. ,Merismopedia minima） ,Carteria sp. and Ankistrodesmus acicularis. The Shan-non-Wiener index （H＇） is generally lower than that of the tourist center and the cruise terminal near the center of the cruise ship, which may be related to the suspension of the icing period. From the biodiversity index, the water quality of wetland is quite clean during freezing period, the phytoplankton resources are abundant and structure is relatively stable, and the biodiversity after melting is better than that in the freezing period. Due to the heterogeneity of environmental factors of space, distribution and density of species change quite a lot among various stations at the same period.