宁夏鹤泉湖浮游植物现状及水质评价

Studies on phytoplankton in Hequan Lake of Ningxia and evaluation of its water quality

1999年 5月至 2 0 0 0年 4月 (除冰封期外 ) ,对宁夏永宁鹤泉湖浮游植物及水化学指标进行了调查研究 ,共采得浮游植物 8门 10纲 16目 34科 5 8属 117种 4变种 ,其中绿藻门 2 5属 48种 1变种 ,硅藻门 16属 36种 3变种 ,蓝藻门 7属 17种 ,黄藻门和隐藻门最少 ,各 1属 2种 .优势种为硅藻、绿藻、蓝藻型 .鹤泉湖浮游植物细胞密度和生物量最大值均在 5月份 ,平均值分别为 2 774.7× 10 4 个 /L和 6 .5 99mg/L ;3月份细胞密度最小 ,平均值为 6 16 .6× 10 4 个 /L ;7月份生物量最小 ,平均值为 2 .5 5 6mg/L ;春、夏、秋三季COD均值为 15 .5mg/L ,溶解氧均值为 8.4mg/L ,总磷均值为 0 .0 36mg/L ,总氮均值为 1.2 2 2mg/L .不同季节浮游植物种类组成的多样性指数 (Shannon Wiener’sindex)为 2 .6 13～ 4.2 0 2 .鹤泉湖水质在 1999年 8月 ,11月和 2 0 0 0年 3月为轻污染 ,其余各月清洁 ,属富营养化湖泊 .

Observations were made on phytoplankton and water-chemistry in Hequan Lake of Ningxia from May 1999 to April 2000.117 species and 4 varieties of phytoplanktons were identified, of which 48 species and 1 variety belong to 25 genera of Chlorophyta,36 species and 3 varieties belong to 16 genera of Bacillariophyta,17 species belong to 7 genera of Cyanophyta,2 species belong to 1 genera of Xanthophyta and of Cryptophyta, which both were the least.The dominant species were Bacillariophyceae,Chlorophyceae and Cyanophyceae.The maximum density both occurred in May.The average density and biomass were 2?774.7×10 4 cell/L and 6.599?mg/L,respectively.The minimum density occurred in March and biomass occurred in July were 616.6×10 4 cell/L and 2.556?mg/L,respectively.The average COD observed in spring,automn and summer were 15.5?mg/L.Dissolved oxygen were 8.4?mg/L.T-P were 0.036?mg/L.T-N were 1.222?mg/L.The diversity indices of phytoplankton composition in different seasons ranged from 2.613 to 4.202 (Shannon-Wiener's index).Hequan Lake is sanitary except for in Augest and November 1999 and in March 2000,the trophyic type is eutrophication.