北京南海子湖藻垫在春夏交替季节水华过程中的作用

藻垫对湖泊水体水华发生是否有影响及影响机制是目前水体富营养化研究的一个前沿课题。本文以北京南海子湖为例,研究湖底藻垫对水体水华爆发的影响。通过对干燥藻垫和水华过程新产生的藻垫进行培养对比实验,揭示不同时期形成的藻垫对水体藻生物量的影响即水华的影响。结果表明,不同干燥时间的藻垫均对水体藻生物量有影响,进入藻生长平台期,水体叶绿素a浓度范围为15~20 μg/L,而灭菌后的藻垫培养水体中叶绿素a浓度低于10 μg/L;水华爆发后新生成的藻垫对水体藻生物量也有贡献,培养水体叶绿素a范围也达到15-20 μg/L;干燥时间对藻垫培养后水体浮游植物生物量的影响较弱。

Role of algal mats in water bloom formation of Nanhaizi lake in Beijing during spring-summer succesion period

The role of algal mats in water bloom is a frontier topic in eutrophication research.The aim of the study is to investigate the impacts of algal mats on water bloom in Nanhaizi lake in Beijing.The dried algal mats from different littoral zones of the lake and newly formed algal mats during water bloom were collected and cultured under various experimental conditions as designed.The experimental results suggested that:(1) the algal mats with different drying times showed impacts on water bloom with a average chlorophyll a content of 15—20 μg/L in cultured water samples,while less than 10 μg/L chlorophyll a content in sterilized controls,(2) the newly formed algal mats also contribute to water bloom with chlorophyll a content of 15—20 μg/L in cultured water samples,(3) the time of algal mats drying has less tendency to impact the phytoplankton biomass in the cultured water samples.