不同风等级扰动对贫富营养下铜绿微囊藻生长的影响

Effect of Disturbance on Growth of Microcystis aeruginosa in Different Nutrient Levels

为了探讨不同营养水平条件下动力扰动对微囊藻生长产生的影响,在实验室中模拟了不同风浪强度,分别测定了铜绿微囊藻生长的速率。结果显示,贫营养下,对藻体有规律地施以一定的扰动有助于藻类的生长,扰动使得藻比增长率从0.1d^-1最大增加至0.3d^-1；约4.0m/s风力最有利于铜绿微囊藻的生长,弱扰动对藻类生长促进作用不明显,强扰动对藻类生长限制作用更显著。富营养下,各风力等级下的扰动对铜绿微囊藻比增长率和最大现存量的影响均不明显,藻比增长率基本间于0.27-0.29d^-1。结果表明,水体中营养水平相差悬殊时,扰动所引起的营养物质重新分配相对于其他因子对藻生长具有更重要的影响。太湖目前的富营养化状况下,动力扰动对藻类生长的直接影响不大。

The specific growth of Microcystis aeruginosa was studied under different nutrient levels and different disturbance in laboratory. It is shown that the algae get better growth under disturbance than stationary state in oligotrophic nutrient water, the specific growth rate can increase from 0.1 d^-1 to 0.3 d^-1 . The algae can get the maximum specific growth rate under the wind speed of 4.0 m/s, relatively low disturbance doesn＇t have obvious impact on algae but relatively high disturbance has evident inhibition effect on algae. In eutrophic nutrient, disturbance has little effect on the growth rate and the biomass, the specific growth is 0.27-0.29 d^-1 . The results show the effect of disturbance on the distribution of nutrients is more important than other factors when the nutrient conditions are quite different in water body. On the condition of nutrient in Lake Taihu, the disturbance doesn＇t have evident effect on the growth of algae.