Effect of flow rate on environmental variables and phytoplankton dynamics: results from field enclosures |
| |
| Authors: | Haiping Zhang Ruihong Chen Feipeng Li Ling Chen |
| |
| Institution: | ZHANG Haiping;CHEN Ruihong;LI Feipeng;CHEN Ling;College of Environmental Science and Engineering,Tongji University; |
| |
| Abstract: | To investigate the effects of flow rate on phytoplankton dynamics and related environment variables,a set of enclosure experiments with different fl ow rates were conducted in an artificial lake. We monitored nutrients,temperature,dissolved oxygen,p H,conductivity,turbidity,chlorophyll-a and phytoplankton levels. The lower biomass in all flowing enclosures showed that flow rate significantly inhibited the growth of phytoplankton. A critical flow rate occurred near 0.06 m/s,which was the lowest relative inhibitory rate. Changes in flow conditions affected algal competition for light,resulting in a dramatic shift in phytoplankton composition,from blue-green algae in still waters to green algae in flowing conditions. These findings indicate that critical flow rate can be useful in developing methods to reduce algal bloom occurrence. However,flow rate significantly enhanced the inter-relationships among environmental variables,in particular by inducing higher water turbidity and vegetative reproduction of periphyton( Spirogyra). These changes were accompanied by a decrease in underwater light intensity,which consequently inhibited the photosynthetic intensity of phytoplankton. These results warn that a universal critical flow rate might not exist,because the effect of flow rate on phytoplankton is interlinked with many other environmental variables. |
| |
| Keywords: | |
| 本文献已被 CNKI SpringerLink 等数据库收录！ |
|
