洱海浮游植物群落结构及季节演替

2011年4月至2012年3月对洱海浮游植物群落结构及季节演替进行了周年调查.结果表明,洱海常见浮游植物有7门、80属、115种；其中,蓝藻门24种,硅藻门16种,绿藻门65种,金藻门和隐藻门各2种,甲藻门和裸藻门各3种.春季以钝脆杆藻(Fragilaria capucina)、直链藻(Melosira sp.)、尖尾蓝隐藻(Chroomonas acuta)为优势种；夏季以直链藻、小环藻(Cyclotella sp.)、转板藻(Mougeotia sp.)、尖尾蓝隐藻、惠氏微囊藻(Microcystis wesenbergii)、乌龙藻(Woronichinia sp.)为优势种；秋季以乌龙藻、游丝藻(Planctonema lauterbornii)为优势种；冬季以游丝藻、水华束丝藻(Aphanizonmenon flos-aquae)、钝脆杆藻为优势种；浮游植物生物量的季节变化表现为秋季最高、夏冬季次之、春季低,最高值出现在11月,达5 899.17×104个/L,最低值出现在2月,为339.21×104个/L.与历史资料相比,近年来洱海浮游植物生物量呈上升趋势,多样性指数降低,蓝藻水华优势种由鱼腥藻转变为微囊藻和乌龙藻,绿藻门细胞数量占浮游植物细胞总数量的比例持续增加.

Community Structure and Seasonal Succession of Phytoplankton in Erhai Lake

The community structure and seasonal succession of phytoplankton were investigated from April 2011 to March 2012 in Erhai Lake. A total of 115 phytoplanktonic algal species belonging to 7 phyla were identified, including 24 species of Cyanophyta , 16 species of Bacillariophyta , 65 species of Chlorophyta, 3 species each of Pyrrophyta and Euglenophyta, and 2 species each of Cryptophyta and Chrysophyta. In Spring, Fragilaria capucina Desm,Chroomonas acuta Uterm and Melosira sp. were the dominant species. In Summer, Chroomonas acuta Uterm, Cyclotella sp., Melosira sp., Mougeotia sp., Microcystis wesenbergii and Woronichinia were the dominant species. In Autumn, Woronichinia sp. and Planctonema lauterbornii were the dominant species. In Winter, Planctonema lauterbornii , Aphanizonmenon flos-aquae and Fragilaria capucina Desm were the dominant species. The biomass of phytoplankton was lower in Spring and Winter than in Summer and Autumn. The peak cell density of algae was 5899.17×104 cells/L in November and the minimum value was 339.21×104 cells/L in February. The biomass of phytoplankton in Erhai Lake has been increasing, and the diversity index reducing. Microcystis wesenbergii and Woronichinia become the dominant species of phytoplankton in stead of Anabeana, the cell density of Chlorophyta has been growing.