浮游植物对摇蚊幼虫扰动的响应研究

为了探究底栖动物扰动对上覆水浮游植物的影响,在实验室设沉积物-水微系统,引入广泛分布的红裸须摇蚊幼虫(Propsilocerus akamusi)和浮游植物,运用微电极等技术方法监测沉积物-水界面理化指标。结果表明,摇蚊幼虫的扰动降低了沉积物间隙水的溶解性有机磷(SRP)向上覆水的释放通量,减少了上覆水的溶解氧(DO)浓度,导致上覆水浮游植物生物量降低和群落结构向适应低磷的物种组成改变。同时,摇蚊幼虫扰动所引起的沉积物DO渗透量与沉积物-水界面SRP通量变化具有显著相关性,浮游植物生物量和上一次沉积物-水界面SRP通量变化有显著相关性,这些结果揭示了摇蚊幼虫通过改变沉积物结构和理化性质,进而能够抑制浮游植物的生长,有利于抑制水华现象的发生。

Research on effect of chironomid larvae bioturbation on phytoplankton

In order to examine the effect of bioturbation of benthic animals on phytoplankton, a laboratory incubation experiment with a sediment-water interface system was carried out. The widely distributed Propsilocerus akamusi and phytoplankton were used in this experiment. The microelectrode system and other techniques were used to monitor the physicochemical indicators of the sediment-water interface system. The results show that the chironomid larvae bioturbation reduced the flux of soluble reactive phosphorus(SRP)released from pore water to the overlying water and decreased the concentration of dissolved oxygen(DO)in the overlying water, leading to a decrease in the biomass and a change of the community structure of the overlying phytoplankton. The amount of DO infiltration in the sediment was significantly correlated with the change of the flux of SRP released from pore water to the overlying water, as was the relationship between the biomass of the phytoplankton and the flux of SRP examined the previous time. All these results indicate that chironomid larvae bioturbation can cause an inhibition of the phytoplankton growth by changing the sediment structure and physicochemical properties, which contribute to the control of alga blooms.