蓝藻堆积对水环境和沉水植物生长的影响

Effect of Cyanobacteria Accumulation on Water Environment and Submerged Plant Growth

湖泊富营养化是世界面临的重大环境问题,针对湖泊富营养化引起的蓝藻(Cyanobacteria)爆发等问题的研究具有重要实践意义,湖泊富营养化常导致蓝藻生物量的增加,水质恶化。本实验于2012年8月12日—9月3日研究添加蓝藻的围隔和对照植被区的水体中总氮(TN)、总磷(TP)、铵氮(NH4+-N)、叶绿素a浓度以及植物生长的区别,并采用自然状态下的水体,研究了蓝藻堆积对水环境和沉水植物生长的影响。研究表明:添加蓝藻的围隔中TN、TP以及叶绿素a含量均显著高于对照区域;蓝藻堆积的围隔中,沉水植物群落总生物量下降,而对照区沉水植物生物量则大量增加;金鱼藻(Ceratophyllum demersum L)、马来眼子菜(Potamogeton wrightii Morong)、伊乐藻和微齿眼子菜(Potamogeton maackianus A.Bennett)等沉水植物的生物量下降,但狐尾藻(Myriophyllum verticillatum)的生物量略有增加。由此得出,蓝藻堆积导致水环境营养盐含量增加,藻类密度增加,沉水植物群落受到抑制,大部分沉水植物的生长受到抑制,但对狐尾藻的影响不大。

Study on cyanobacteria outbreak caused by lack eutrophication,which is a global environmentproblem,has practical significance.Eutrophication process plays a key role in cyanobacteria outbreak andcauses water quality deterioration.In experiment under natural water environment from Aug.12,2012 to Sep.3,2012,through difference analysis of TN,TP,NH4＋-N and Chl a between enclosures with cyanobacteria andopen water with no cyanobacteria,we studied the effects of cyanobacteria accumulation on water environmentand growth of submerged macrophytes.Results showed that：in enclosure with accumulation of cyanobacteria,the TN,TP and Chl a were higher than that in open water contrast.Cyanobacteria accumulation resulted indeclining of biomass of the whole submerged community,comparing to a great increase in open water contrast.In conclusion：cyanobacteria accumulation could cause nutrients increase in water environment and lead to the density increase of algae and decrease of most submerged macrophytes except Myriophyllum verticillatum.