亚热带大型河流型水库——富春江水库浮游植物群落及其与环境因子的关系

Phytoplankton community and its relationship with environmental factors of a large riverine reservoir,Fuchunjiang Reservoir in subtropical China

为了掌握富春江水库浮游植物群落特征，探寻其与环境因子的关系，于2006年1月至2007年12月，对其进行了20次采样调查．鉴定结果表明富春江水库共有浮游植物107种，浮游植物密度范围在0．21×10^5-3．01×10^7cells／L之间．浮游植物组成随季节变化有所不同，春季绿藻、隐藻、硅藻占优势，夏季蓝藻和硅藻占优势，秋冬季硅藻、隐藻占优势．浮游植物群落结构受水文条件的影响较大，浮游植物密度与水体温度呈显著正相关，与透明度在不同范围内表现出不同的相关关系;与TN、即在不同范围内表现出不同的相关关系，与TN／仰及可溶性硅呈显著正相关．库区总氮和总磷浓度均很高，足够满足藻类生长需要；TN／TP较低，基本在8—30之间，说明氮磷含量不是富春江库区藻类生长的限制因子．水文季节性变化会明显地影响浮游植物群落结构和密度的季节性变化，特别是降雨、水温及水力滞留时间等因子是影响水库浮游植物群落结构及密度变化的主要因子．

During January 2006 to December 2007, phytoplankton and environmental factors were monitored for twenty times in Fuchunjiang Reservoir. A total of 107 taxa were identified by microscope. The phytoplankton density was ranged from 0.21 × 10^5 - 3.01 × 10^7 cells/L. The specific composition of phytoplankton community changed with the seasons. Bacillariophyta, Chlorophyta and Cryptophyta dominated in Spring; Cyanophyta and Bacillariophyta dominated in Summer; and Bacillariophyta and Cryptopbyta dominated in Autunm and Winter. The structure of phytoplankton community was obviously affected by hydrological conditions. There was significant positive correlation between phytoplankton density and water temperature. The correlation coefficients between phytoplankton density and transparency, TIN, TP varied in different ranges. Pbytoplankton density was significant positive correlations with water temperature, TN/TP, and soluble silicon. TN and TP concentrations were high enough to meet the needs of algal growth. Low N/P between 8 to 30 showed that nitrogen and phosphorus content may not be limiting factors for the growth of algae in Fuchunjiang Reservoir. The seasonal change of phytoplankton community and density were obviously affected by seasonal change in hydrological, especially by precipitation, water temperature and water retention time.