机构地区: 同济大学环境科学与工程学院长江水环境教育部重点实验室
出 处: 《环境科学》 2010年第1期69-75,共7页
摘 要: 利用3个围隔装置,于2007年8月~2008年7月间研究了0.002、0.10、0.15和0.30 m.s-1共4种表面流速对围隔内浮游植物和浮游动物生长的影响.结果表明,0.15、0.30 m.s-1这2种表面流速下围隔内壁附着水绵生物量分别是对应静止条件下的2.3倍和31.3倍,0.10、0.15和0.30 m.s-1这3种表面流速下围隔内Chl-a浓度分别为对应静止围隔中的45%、54%和26%,浮游动物生物量分别为对应静止围隔中的38%、27%和6%.这些现象的作用机制可能在于水动力产生的剪切力促进水绵的营养生殖、紊动强制裹挟浮游植物破坏其光生境、水绵繁殖抑制浮游植物生长和水动力扰动降低浮游甲壳动物捕食成功率. To explore the effects of hydrodynamics on plankton,four kinds of surface flow enclosure experiments were done from August,2007 to July,2008.The flow velocity were 0.002,0.10,0.15 and 0.30 m·s^-1 respectively.Under 0.15 and 0.30 m·s^-1 surface velocity conditions,it was revealed that Spirogyra biomasses were 2.3 times and 31.3 times of the ones under static state respectively.Under 0.10,0.15 and 0.30 m·s^-1 conditions,Chl-a concentrations were 45%,54% and 26% of the ones under statistic state while zooplankton biomasses were 38%,27% and 6% respectively.The mechanism is that a certain flow velocity stimulates Spirogyra growth may be for the shear stress generated by the surface flow can help the vegetative reproduction.Shear stress and turbulence may also bring the phytoplankton to the light limited area by force.Besides,as Spirogyra grows well,it can inhibit the phytoplankton growth by excretion or some symbiotic microorganism.When shear stress or water turbulence exceeds a certain value,.crustacean zooplankton successful grazing rate may also be depressed.