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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 |
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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 |
