长江口九段沙湿地及其附近水域浮游植物群落结构特征

Characteristics of Community Structures of Phytoplankton in the Jiuduansha Wetland and its Adjacent Waters of the Yangtze River Estuary

于2012年春、夏、秋和冬季对九段沙湿地及其附近水域（吴淞口至九段沙下沙东面）进行了浮游植物调查,初步研究了九段沙湿地及其附近水域浮游植物的群落结构,并讨论了其与环境因子的关系.此次调查共记录列浮游藻类139种,隶属于8门84属.硅藻门占总种类数的51%,其次为绿藻门.种类数占31%,主要种类的生态类群包括淡水、近岸和广盐3大类.冬季浮游植物生物量最低.平均浮游植物细胞丰度为（12.6±1.2）×10~4个/L;春季浮游植物生物量最高.平均浮游植物细胞丰度为（117.3±6.5）×10~4个/L.浮游植物生物量主要由中肋骨条藻贡献,其分布状况决定了水域浮游植物平面分布格局.此外,不同季节影响浮游植物分布的因素存在差异.冬季的低水温是限制浮游植物生长的主要因子;春季盐度上升是促进其生长的主要因素;夏季丰水期强径流带来的营养盐则是影响浮游植物生长的主要因素.

The phytoplankton of ten sampling sites between Wusong Estuary and Lower Jiuduansha was investigated seasonally in spring, summer, autumn and winter in 2012. Community structure and their relationship with environmental factors were also discussed. 139 species of phytoplankton belonging to 84 genera were found in this investigation. The species of diatom was the most and took 51% of all species. Green algae was the second, taking 31% of all species. The major phytoplankton species, according to their ecotype and habitat, can be grouped into freshwater, coastal and eurysalinity. The phytoplankton biomass in winter was the lowest and in spring was the highest. The average cell abundance of phytoplankton in winter was （12.6 ± 1.2）× 104 cell/L and was （117. 3±6.5）× 104 cell/L in spring, respectively. The Skeletonema costatum was the single dominant species in all seasons and led to low diversity and uneven distribution. In addition, the environmental factors affecting the quantity distribution characters of phytoplankton differed in different seasons. Water temperature was the main limiting factor for phytoplankton growth in winter. Salinity greatly promoted phytoplankton growth in spring. The strong flows of wet season in summer led to rich nutrient advantageous to phytoplankton growth.