长江口九段沙湿地近岸水域浮游植物群落结构的特征

2010年10月至2011年7月按季度对长江口九段沙湿地近岸水域18个站点的浮游植物群落结构和物种多样性的周年季节变化进行了初步研究。共鉴定出浮游植物133种,隶属于6门55属,主要类群为硅藻,其种类数占总种类数的61.65%。浮游植物的年平均细胞丰度为(92.33±29.86)×104细胞/L。根据浮游植物的生态类型及其生境特征基本上可分为3大类群:淡水类群、近岸广盐类群、高盐性外海类群。中肋骨条藻(Skeletonema costatum)为第一优势种,年平均细胞丰度为(87.95±30.96)×104细胞/L。正是由于其细胞丰度和出现频率上的绝对优势,导致研究水域单一优势种突出,多样性低,种间分布不均匀,群落结构简单化。

Characteristics of community structures in the Jiuduansha inshore waters of the Yangtze River estury

A preliminary study was conducted on the community structure of phytoplankton and the annual variation of species diversity quarterly from October 2010 to July 2011 at the 18 stations in the Jiuduansha inshore waters of the Yangtze River estuary. A total of 133 phytoplankton species were identified, which belonged to 55 genera of 6 phyla. Diatom was the major phytoplankton group and its species number accounted for 61.65% of all species. The annually average cell abundance of phytoplankton was (92.33±29.86) ×104cell?L-1.The phytoplankton, according to its ecotype and habitat, can be grouped into freshwater, coastal and eurysalinity and oceanic species. The main dominant species was Skeletonema costatum, of which average cell abundance was (87.95±30.96) ×104cell?L-1. It was the absolute superiority in cell abundance and frequency occurrence of Skeletonema costatum that resulted in the prominence of the single dominant species, lower diversity, uneven distribution and community simplification of the waters.