江苏近岸海域夏季浮游植物的分布特征及多样性

根据江苏近岸海域2006年夏季浮游植物调查的结果,对浮游植物种类、细胞丰度及其水平分布、多样性特征等进行了分析,结果显示:江苏近岸海域浮游植物种类丰富,共鉴定种类6门57属156种;细胞丰度较高,整个海区年平均密度为4.98×106ind/m3。硅藻在细胞丰度上占绝对优势,平均为4.63×106ind/m3。浮游植物种类数的平面分布表现为南高北低,高密区主要分布在长江口北支、南通海域南部等区域。聚类分析结果显示,江苏近岸海域春季浮游植物可以分成3个类群,即双尾藻—佛氏海毛藻—角藻类群,中肋骨条藻类群和圆筛藻类群。香农—威纳多样性指数、Pielou均匀度指数和Margalef指数水平分布则是北高南低,细胞丰度较高的区域多样性水平较低。

The Distribution Characteristics and Species Diversity of Phytoplankton in Offshore Water of Jiangsu Province in Summer

On the base of the survey data of phytoplankton in offshore water of Jiangsu Province in summer of 2006 , this paper studied the species composition , the horizontal distribution of cell abundance and species diversity of phytoplankton in the area. The results showed that the area was rich in phytoplankton with 156 species collected , including 57 genera , 6 classes. The average of cell abundance of phytoplankton were 4.98×10 6 ind/m 3, the average of cell abundance of bacillariophy were 4.63×10 6 ind/m 3 .Bacillariophy was the dominant in cell abundance and species richness. The horizontal distribution of cell abundance was relatively high in south zone of survey waters. The highest density area of phytoplankton was near the Yangtze River estuary and southern waters of Nantong. Based on the results of cluster analysis , the phytoplankton assemblages can be divided into three groups. Group 1 was composed of Ditylum , Thalassiothrix frauenfeldii and Ceratium. Group 2 was represented by Skeletonema costatum , Group 3 included mainly Coscinodiscus.Shannon — Weaver index , Pielou index , Margalef index was relatively high in north zone of survey waters , and the biodiversity of phytoplankton community was generally low in the area with high cell abundance.