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摘要: |
风浪扰动在湖泊和水库中频繁发生,是影响湖泊生态系统的重要因素之一。为了解太湖风浪扰动对水华微囊藻群体生长的影响,并探究其影响机理,利用室内摇床试验,设置不同的扰动强度(0、50、100、200、400 r/min)来模拟太湖风浪扰动,扰动时间为24 h,并测定不同扰动强度下水华微囊藻群体生长和叶绿素荧光参数。结果表明,所有试验组中,100 r/min组的ρ(Chla)、微囊藻数量、Fv/Fm(潜在最大光合效率)、ETRmax(潜在最大光合速率)、Ik(半饱和光强)和α(光能利用效率)增加最快,试验结束时分别为扰动前的3.29、10.75、1.20、2.30、2.21和1.21倍;且,扰动结束后,100 r/min组中3-10细胞群体细胞数量由25.80%降至20.70%, 显著低于对照组(P<0.05),而>10细胞群体细胞数量由0增至25.55%,显著高于对照组(P<0.05)。方差分析表明,试验第7 d~第11 d,100 r/min组的ρ(Chla)、水华微囊藻数量、Fv/Fm、ETRmax和α显著高于对照组(P<0.05);第1 d~第5 d,400 r/min组的ρ(Chla)、ETRmax和Ik显著低于对照组(P<0.05)。该结果表明,适宜的扰动强度(100 r/min)促进水华微囊藻群体生长和光合活性,过高的扰动强度(400 r/min)则抑制水华微囊藻群体生长和光合活性。 |
关键词: 水华微囊藻 群体 扰动强度 叶绿素荧光 太湖 |
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基金项目:国家自然科学基金重点项目(41230744;40825004),国家水体污染控制与治理科技重大专项项目(2012ZX07503-002;2012ZX07101-013-03)联合资助 |
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Effect of Disturbance Intensity on the Growth and Chlorophyll Fluorescence of Microcystis flos-aquae colony in Lake Taihu |
HAN Lihua,YANG Guijun,LIU Yu,QIN Boqiang,ZHONG Chunni,YANG Hongwei,et al
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Abstract: |
Disturbance induced by Wind-wave occurs frequently in lakes and reservoirs, and it is one of the important factors affecting the lakes ecosystem. To understand the effect and mechanism of mixing induced by wind-wave on the growth of Microcystis flos-aquae colony in Lake Taihu, an experiment was conducted in lab, using different disturbance intensity (0, 50, 100,
200, and 400 r/min) by agitator to simulate the mixing induced by wind-wave in Lake Taihu. The disturbance time is 24 h. Growth and chlorophyll fluorescence parameters of Microcystis flos-aquae colony were measured in this study. The study results showed that the increasing speeds of ρ(Chla), abundance, Fv/Fm (the potential maximum photosynthetic efficiency), ETRmax (the potential maximum photosynthetic rate), Ik (half saturation light intensity) and α (light use efficiency) of M. flos-aquae in the 100 r/min groups were the highest among all treatment groups. In the end of this experiment, the value of ρ(Chla), abundance, Fv/Fm, ETRmax, Ik and α of M. flos-aquae in the 100 r/min groups were 3.29, 10.75, 1.20, 2.30, 2.21 and 1.21 times as more as that before mixing in this experiment. In the end of this experiment, the cell abundance of 3-10 cells colony of M. flos-aquae in the 100 r/min groups decreased from 25.80% to 20.70% to total cell abundance,and which was significantly lower than that in the control groups (P<0.05). However, the cell abundance of >10 cells colony of M. flos-aquae in the 100 r/min groups increased significantly from 0 % to 25.55% to total cell abundance, which was significantly higher than that in the control groups (P<0.05).The variance analysis showed that the ρ(Chla), abundance, Fv/Fm, ETRmax and α of M. flos-aquae in the 100 r/min groups were significantly higher than those in the control groups (P<0.05) during the 7 th - 11 th day in the experiment. During the 1 th - 5 th day, the ρ(Chla), ETRmax and Ik in the 400 r/min treatment groups were significantly lower than those in the control groups (P<0.05) in the experiment. The results showed that the suitable disturbance intensity (100 r/min) promoted the growth and photosynthetic activity of M. flos-aquae, but the high disturbance intensity (400 r/min) inhibited the growth and photosynthetic activity of M. flos-aquae. |
Key words: Microcystis flos-aquae Colony Mixing intensity Chlorophyll fluorescence Lake Taihu |