江苏里下河腹部地区湖泊湖荡春季浮游植物群落结构和营养状态

以江苏省里下河腹部地区38个典型湖泊湖荡为研究对象,分析了春季浮游植物群落结构特征及其与环境因子的关系,运用了基于理化指标的综合营养状态指数(TLI)评价方法和基于浮游植物群落结构分析的生物指标(Shannon-Wiener多样性指数H′和Pielou均匀度指数J)评价方法,评价了湖泊湖荡营养状态.结果显示共采集到里下河腹部地区湖泊湖荡浮游植物7门50属89种,主要隶属于绿藻门(Chlorophyta)和硅藻门(Bacillariophyta);浮游植物细胞丰度介于2.3×10~5～3.7×10~7 cells·L~(-1),生物量介于0.05～15.02 mg·L~(-1),绿藻门与隐藻门(Cryptophyta)在细胞丰度上占优势,隐藻门在生物量上占优势;梅尼小环藻(Cyclotella meneghiniana)、啮蚀隐藻(Cryptomonas erosa)、尖尾蓝隐藻(Chroomonas acuta)、四尾栅藻(Scenedesmus guadricauda)为主要优势种;生物指标评价方法的结果显示湖泊湖荡总体为轻度富营养,与TLI评价方法的结果有较好一致性,表明两类评价方法在里下河腹部地区具有较强内在关联性.

Phytoplankton community structure and trophic status of lakes in the Lixia River hinterland of Jiangsu Province in spring

This study selected 38 typical lakes in the Lixia River hinterland of Jiangsu Province to analyze the phytoplankton community structure in spring and its relationship to the hydro-environmental factors. Meanwhile, the trophic status of the lakes was assessed through the trophic level index (TLI) method based on physicochemical indicators as well as the biological indicators method based on the Shannon-Wiener diversity index (H'') and the Pielou evenness index (J). A total of 89 phytoplankton species were identified in all lakes, which belongs to 50 different genera and 7 phyla. Chlorophyta and Bacillariophyta were two dominated phyla in the communities. The cell abundance of phytoplankton ranged from 2.3×10⁵ to 3.7×10⁷ cells·L^-1, in which Chlorophyta and Cryptophyta were dominant. The biomass of phytoplankton ranged from 0.05 to 15.02 mg·L^-1, in which Cryptophyta was dominant. The dominant species included Cyclotella meneghiniana, Cryptomonas erosa, Chroomonas acuta and Scenedesmus guadricauda. The evaluation results based on biological indicators demonstrate that the lakes are in light eutrophication status, which is consistent with the results analyzed with TLI method. It reveals that there is a strong inherent relevance between two evaluation methods for the lakes of the Lixia River hinterland.