苏北骆马湖浮游植物群落结构及其水质生物评价

摘要

为了解骆马湖浮游植物的群落结构及其水质健康状态,于2014年对骆马湖浮游植物进行逐月野外调查研究.共鉴定出浮游植物7门71种属,其中蓝藻门和硅藻门最多,其次为绿藻门.全湖细胞丰度在1.52× 106～7.89× 106 cells/L之间,全湖生物量在0.048～ 12.44 mg/L之间.非多维度量尺度分析结果显示,骆马湖全湖浮游植物生物量从冬春季喜低温的硅藻门为主演替到夏秋季喜高温的蓝藻门为主,表明骆马湖浮游植物有着明显的季节演替规律.与20世纪相比,骆马湖浮游植物优势种属有着很大的变化,富营养化指示属隐藻、纤维藻、针杆藻、鱼腥藻、伪鱼腥藻等明显增多,表明自20世纪以来,骆马湖富营养化程度正在加剧.与邻近的洪泽湖、南四湖、高邮湖、邵伯湖和宝应湖相比,骆马湖浮游植物细胞丰度高于宝应湖,但低于其他4个湖泊.基于浮游植物的水质评价结果,骆马湖目前处于从寡污带向β-中污带过渡的状态,富营养化程度轻于洪泽湖,与南四湖部分湖区富营养化程度相似.%Phytoplankton was investigated monthly in Lake Luoma,northern Jiangsu Province from January to December of 2014 in order to study the structure of phytoplankton community and the bio-assessment of water quality.A total of 7 phyla,including 71 genera or species of phytoplankton were identified.Chlorophyta was the most abundance taxa and followed by Cyanophyta and Bacillariophyta.The phytoplankton abundance of the whole lake was ranged from 1.52×106 cells/L to 7.89×106 cells/L,and the biomass was ranged from 0.048 mg/L to 12.44 mg/L.Nonmetric multidimensional scaling analysis demonstrate that the phytoplankton structure has obvious seasonal succession pattern.Compared to the 20th century,dominant genera have changed obviously.For example,the indicator genera of eutrophication,such as Cryptomonas,Ankistrodesmus,Synedra,Anabaena and Pseudanabaena have increased significantly,which indicates the increasing eutrophication trend of Lake Luoma since the last 20th century.Lakes Nansi,Hongze,Shaobo,Baoying and Gaoyou are close to Lake Luoma and are all connected by the Grand Canal.Compared with the four nearby lakes,the phytoplankton abundance in Lake Luoma are higher than that in Lake Baoying.Based on the bio-assessment of water quality,Lake Luoma has been suffered a transform from oligosaprobic zone to β-mesosaprobic zone pollution,and its eutrophication degree is lower than that of Lakes Hongze,Shaobo,Gaoyou,and is similar with some zones of Lake Nansi.