包头南海湖非冰封期浮游植物的时空动态特征

为了解包头南海湖浮游植物群落非冰封期的时空动态特征,2017年5-10月,在南海湖设置了12个监测站位,监测浮游植物时空变化,并同步监测水环境因子。结果表明,南海湖12个站位共鉴定出浮游植物146种(含变种);其中,绿藻门(Chlorophyta)59种,蓝藻门(Cyanophyta)31种,硅藻门(Bacillariophyta)37种,裸藻门(Euglenophyta)9种,金藻门(Chrysophyta)5种,黄藻门(Xanthophyta)3种,隐藻门(Cryptophyta)2种。浮游植物密度为23.35×10~6～115.59×10~6个/L;优势度分析表明,5-6月主要以绿藻占优势,优势种为四尾栅藻(Scenedesmus quadricauda)和螺旋弓形藻(Schroederia spiralis);7-9月主要以蓝藻占优势,优势种为微小平裂藻(Merismopedia tenuissima)和水花束丝藻(Aphanizomenon flosaquae);10月以绿藻和硅藻占优势,优势种为四尾栅藻和近缘针杆藻(Synedra affinis)。空间上呈现出沿进水口向湖心区逐渐递增的趋势,湖心区整体密度较高,而排污口和芦苇区处密度相对较低;冗余分析(RDA)表明,氨氮、化学需氧量、pH、叶绿素-a以及水温是影响浮游植物分布的主要水环境因子,绿藻与总氮关系密切,蓝藻主要受总磷的影响,硅藻受pH影响较大。

Temporal and Spatial Dynamics of Phytoplankton in Nanhai Lake, Baotou, during the Ice-free Period

From May to October in 2017, the phytoplankton community and water environmental factors in 12 spots of Nanhai Lake were investigated.Analysis the dynamic featuresof phytoplankton community and its relationship with water environmental factors.The results showed that a total of 146 species of 7 genera of 77 phyla of phytoplankton were found during the survey.The most diverse group was Chlorophyta(59 species),which account for 40.41% of the total recorded species,following by Cyanophyta and Bacillariophyta(37 species,31 species),which account for 25.34% and 21.23% respectively. The highest number of phytoplankton species in July was 102 species and the least species in October was 57 species; The number of phytoplankton species was large difference in spatial that the most species in reed area was 95 species and the least species in the outfall area was 54 species; The dominant species included Oscillatoria tenuissima Aphanizomenon flosaquae and Schroederia spiralis;The cell density of phytoplankton was 23.35×106~115.59×106cells/L,which Chlorophyta Cyanophyta and Bacillariophyta were the dominant contributors in spring, summer, autumn respectively. RDA showed that ammonia nitrogen, chemical oxygen demand, pH and chlorophyll were the most important water environment factors influencing the distribution of phytoplankton species. Chlorophyta were closely related to the total nitrogen, Cyanophyta were more affected by pH, Bacillariophyta were mainly affected by total phosphorus.