热带直流型水库蓝藻季节变化特征

Seasonal Fluctuation of Cyanobacteria Population in Tropical Through-flowing Reservoirs in South Asia

摘要:

于2004年调查了广东省飞来峡和深圳两座直流型水库的蓝藻季节分布特征。共检到蓝藻17属，绝大多数为丝状体种类。常见属有假鱼腥藻（Pseudanabaena）、微囊藻（Microcystis）和蓝纤维藻（Dactylococcopsis）。蓝藻细胞密度为5~2 052个细胞/毫升。深圳水库最高蓝藻细胞密度出现在6月，其中丝状蓝藻的相对丰度在75%以上；飞来峡水库最高蓝藻细胞密度出现在12月，丝状蓝藻的相对丰度达到90%。水动力学条件是限制蓝藻丰度和种类的主要环境因子。由于飞来峡水库的水力滞留时间变化较大，所以蓝藻季节性变化受水动力学条件的影响比深圳水库的大。假鱼腥藻等丝状蓝藻更适合在水库中生长，特别是在氮磷营养水平较高，水力滞留时间明显增加时，其细胞密度将大幅度上升。

Abstract:

The seasonal fluctuation of cyanobacteria population in the through-flowing reservoirs of Shenzhen and Feilaixia in Guangdong Province was investigated in 2004. Seventeen genera of cyanobacteria composed mainly of filamentous ones were obtained. The common genera were Pseudanabaena, Microcystis and Dactylococcopsis. Cyanobacteria density ranged from 5 to 2 052 cells ml-1. The maximum cell density was found in Shenzhen Reservoir in June with filamentous species abundance of over 75%. The peak of cyanobacteria abundance was present in Feilaixia Reservoir in December with filamentous species occupying 90%. Cyanobacteria abundance and composition were changed mainly by hydraulic condition. The seasonal fluctuation of cyanobacteria population was more affected in Feilaixia Reservoir than in Shenzhen Reservoir since the hydraulic retention time of Feilaixia Reservoir had a greater variation than that of Shenzhen Reservoir. Filamentous cyanobacterias, especially Pseudanabaena, adapt to the reservoirs better than the other cyanobacteria species under high levels of nitrogen and phosphorus conditions. And their abundances will greatly increase when the retention time is prolonged.