万峰湖浮游植物群落的时空分布

Temporal and spatial characteristics of phytoplankton community in Wanfeng Reservoir

于2009年9月（夏季）和2010年1月（冬季）对万峰湖（水库）的浮游植物群落结构时空分布特征进行研究。在万峰湖共监测到浮游植物49种,其中夏季水库表层（0~10m）浮游植物优势种为蓝藻门中的拟柱孢藻（Cylindrospermopsis rackiborskii）,底层为硅藻门中肘状针杆藻（Synedra ulna）和梅尼小环藻（Cyclotella m eneghiniana）;在冬季以硅藻门中的小环藻（Cyclotellasp.）和梅尼小环藻为主。夏季,浮游植物表层丰度为13.0×104~54.6×104cells.L-1,野鸭滩（S2）最高,而以坝艾（S4）浮游植物丰度最低;浮游植物主要集中在表层（0~10 m）,以蓝藻组成为主,蓝藻丰度百分数在大坝（S1）最高,达到90.3%,香浓多样性指数夏季高于冬季,夏季表层均匀度指数最低。冬季,浮游植物丰度为17.43×104~25.28×104cells.L-1,浮游植物主要集中在表层（0~10 m）和中层（10~50 m）,水体的各层硅藻所占比例均在90%以上。从浮游植物群落结构和丰度看,万峰湖处于中营养状态,冬季水质好于夏季。夏冬两季浮游植物丰度与水体的温度及水深都表现出了较强的相关关系。

To understand the temporal and spatial characteristics of phytoplankton community structure in Wanfeng,a deep altiplano reservoir,phytoplankton was measured in September,2009 and January,2010.Forty-nine species of algae were identified.In summer the community was dominated by Cylindrospermopsis rackiborskii at the surface（0-10 m） and at the bottom（60 m） Synedra ulna and Cyclotella meneghiniana became dominant,but in winter the community was dominated by Synedra ulna and Cyclotella meneghiniana.The phytoplankton abundance ranged from 13.0×104 to 54.6×104 cells·L-1 in summer and 17.43×104 to 25.28×104 cells·L-1 in winter.The maximum phytoplankton abundance was at Yeyatang（S2）,but the minimum phytoplankton abundance was at Baai（S4）.In summer,phytoplankton collected at the surface（0-10 m） was primarily composed of cyanophyta.The highest percent composition of cyanophyta was 90.3% at Daba（S1）.Shannon diversity index was higher in summer than in winter,but the evenness was lowest at the surface in summer.In winter,phytoplankton mainly distributed at the surface（0-10 m） and at the mid-level（10-50 m）,and was primarily composed of bacillariophyta.The percent composition of bacillariophyta was above 90% in all water layers.Judged by phytoplankton community structure and abundance,Wanfeng Reservoir is mesotrophic in summer.Water quality was better in winter than in summer.A relationship between phytoplankton abundance,temperature,and water depth was obvious in winter and summer.