摘要
本工作在洋河水库现场进行了＂水华＂发生的实验研究，采用以受控生态系统实验（Ｃｏｎ－ｔｒｏｌｌｅｄＥｘｐｅｒｉｍｅｎｔｅｄＥｃｏｓｙｓｔｅｍ）为主，结合对自然水体进行观测的方法，观察了从藻类增殖到＂水华＂形成及消失的全过程；定量研究了＂水华＂发生所需的条件。研究表明：水体的富营养状态是藻类异常增殖的主要原因，而藻类的异常增殖又是＂水华＂发生的前提条件。＂水华＂发生时水体表层所需的藻类生物量阈值为４８．０μｇ．Ｃｈｌａ／１。气象因子引起的藻类聚集对于＂水华＂的发生具有诱导作用。当处于水温２６℃、光照２３０００Ｌｕｘ左右的条件下，最适于藻类上浮聚集，小于２ｍ／ｓ的微风能使藻类发生漂移聚集。实验中估算出，藻类的垂直聚集参数为１．２３，水平漂移聚集参数达１５．７，藻类的总聚集参数为１９．３。实验发现，水体中的氮、磷负荷决定了藻类的增长峰值，磷源浓度与藻类的增长率有明显的相关性。实验求得，洋河水库中铜绿微囊藻（Ｍｉｃｒｏｃｙｓｔｉｓａｅｒｕｌｆｉｎｏｓａ）在夏季所能达到的最大增长率为１０．４２μｇ．Ｃｈｌａ／１．ｄ，它对磷吸收的半饱和浓度常数等于０．０７８×１０￣（－６）。
The research was conducted in a controlled experimented Ecosystem in Yanghe Reservoir.Combined with direct monitoring on the studied water-body,this research observes the whole procedure from the rapid growth of algae population through the disappearance of algae bloom. Controlling factors contributing to the formation of algae bloom are also included in the study.The result shows that eu-trophication is the major reason responsible for the bloom formation and the abnor-mal growth of algae population composes the premise of this procedure.The thresh-old of bloom formation on the surface of reservoir is 48.0ug/l.A condition with 26℃ temperature and 23000 lux light intensity is proved to be optimum for up一floating and assemblage of algae population. Breeze with velocity of less than 2m/scan accelerate the assemblage procedure. It is estimated that the index of vertical as-semblage and horizontal drifting assemblage are 1.23 and 15.7 respectively.Theoverall assemblage index is 19.3.Experiment shows that the concentration capacities of N and P determine thepeak value of algae growth.A significant relationship between concentration of Pand growth rate of algae is identified.In Yanghe Reservoir,the summer growth rateof Microcystis aeruginosa can reach 10.42 μg. Chla/l.d while the semi一saturationconstant for P absorption is 0.078×10￣(-6).
出处
《北京大学学报（自然科学版）》
CAS
CSCD
北大核心
1994年第4期476-484,共9页
Acta Scientiarum Naturalium Universitatis Pekinensis
关键词
水华
生态系统
水库
环境生物学
algae bloom(water bloom)
eutrophication
controlled experimented ecosystem
reservoir
