黑河金盆水库浮游藻类群落季节性变化特征研究

The Characteristics of Seasonal Variation of Phytoplankton Community in Heihe Jinpen Reservoir

黑河金盆水库自2003年建成蓄水以来,库水富营养状况呈逐年加剧的变化趋势,个别月份曾爆发大面积蓝绿藻水华,严重威胁城市供水系统安全.2008年3月至2010年3月,对原水浮游藻类的调查结果表明:金盆水库当前含典型浮游藻类5门31属,其群落结构季节性演变总体呈现"冬春季硅藻为主,夏秋季蓝、绿藻占优"的演替特征;水库藻类数量季节性变化则呈现典型的"双峰式"分布特征,每年4—5月和7—9月均会出现藻类高发现象;藻类数量与水温呈显著正相关,与库水位呈显著负相关,与总氮、总磷的相关性并不显著;该水库藻类生长基本不受氮、磷营养盐限制,但磷依然是限制性营养因子;水库季节性热分层现象可导致水体稳定性长期较高,从而促进微囊藻等蓝藻种群大量繁殖并呈季节性暴发态势.

The water eutrophication in Jinpen reservoir increased year by year since 2003 when the reservoir was built, such as the occurrence of blue-green algal blooms in several months which had seriously threatened the safety of urban water supply system. According to the survey on the planktonic algae in the raw water from March 2008 to March 2010, the results indicated that the typical planktonic algae in Jinpen reservoir at present included 5 phyla and 31 genera, however the seasonal evolution of algal community structure embodied the regularity that the diatom became the major group in spring and winter and the blue-green algae dominated in summer and autumn every year. The seasonal variation of algal abundance showed a type of double-peak distribution characteristic, which the algal blooms appeared in the periods of annual April to May and July to September. The amount of algae had significant positive correlation with water temperature, and negative correlation with water level of Jinpen reservoir, however it was not significantly correlated with TN and TP. Even though, the concentration of nitrogen and phosphorous in raw water could satisfied the algae growth, the phosphorous was still considered to be the limiting factor among various nutrients. The phenomenon of seasonal thermal stratification in Jinpen reservoir could effectively strengthen the water stability which promoted the growth of algae species such as microcystis, cyanobac- teria and so on, therefore inducing the seasonal outbreak of algal blooms in a way.