| 藻华聚集的生态效应:对凤眼莲叶绿素和光合作用的影响 |
| 摘要点击 1837 全文点击 869 投稿时间：2014-11-19 修订日期：2015-03-18 |
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| 中文关键词 藻华聚集 生态效应 凤眼莲 叶绿素 光合作用 |
| 英文关键词 algae bloom cluster ecological effects water hyacinth chlorophyll photosynthesis |
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| 中文摘要 |
| 以凤眼莲为研究对象,模拟凤眼莲叶绿素和光合作用变化对不同蓝藻水华聚集影响的应答响应. 通过深入研究藻华聚集后对水生植物的生理影响,以揭示藻华规模性暴发引起水生植物消亡的深层机制和更好地发挥植物的水体生态修复功能. 结果表明,藻华聚集后2 h内溶氧会耗尽,水体中氧化还原电位值(ORP)降至-200 mV,添加60 g·L-1和120 g·L-1新鲜藻细胞的处理1、2中溶解性总氮(DTN)含量分别高达44.49 mg·L-1、111.32 mg·L-1,溶解性总磷(DTP)含量分别高达2.57 mg·L-1、9.10 mg·L-1,植物根区NH4+-N含量增加至32.99 mg·L-1、51.22 mg·L-1,形成厌氧、强还原、高营养盐环境而对凤眼莲产生胁迫作用,植物叶片叶绿素浓度呈现先增加、后降低的变化趋势,处理2的叶片光合能力、气孔导度(以CO2计)则呈现快速下降,至实验结束时下降为3.95 μmol·(m2·s)-1、0.088 μmol·(m2·s)-1,同期对照组叶片光合能力、气孔导度分别为22μmol·(m2·s)-1、0.78 μmol·(m2·s)-1,表明凤眼莲对环境胁迫有较强的光合应答响应; 实验中发现处理1中老根系脱落、大量白色嫩根长出,处理2中老根系大量死亡、脱落,无白色新根长出,同时叶片发黄、枯焦开始死亡,表明在超过了凤眼莲的抗逆境能力后,就开始出现根系死亡、光合能力受到抑制,植物开始死亡,表明在藻华聚集后形成的水体生态环境恶化对凤眼莲产生重度胁迫,使植物生理功能受到抑制是导致植物死亡的主要原因之一. |
| 英文摘要 |
| The response of chlorophyll and photosynthesis of water hyacinth leaves in different concentrations of clustered algae cells was studied in the simulation experiment, and the aim was to reveal the mechanism of the death of aquatic plants during algae blooms occurred through studying the physiological changes of the macrophytes, so as to play the full function of the ecological restoration of the plants. And results showed the dissolved oxygen quickly consumed in root zone of aquatic plants after algae blooms gathered and showed the lack of oxygen (DO<0.2g·L-1); and the ORP was lower than -100 mV after 1 d, and it declined to -200 mV at the end of the experiment. There were lots of nutrients releasing to the water after the algae cell died and concentration of DTN in treatment 1 and 2 were 44.49 mg·L-1 and 111.32 mg·L-1, and the content of DTP were 2.57 mg·L-1 and 9.10 mg·L-1, respectively. The NH4+-N concentrations were as high as 32.99 mg·L-1 and 51.22 mg·L-1, and the root zone with the anoxia, strong reducing, higher nutrients environment had a serious stress effects to the aquatic plants. The macrophytes photosynthesis reduced quickly and the plant body damaged with the intimidation of higher NH4+-N concentration (average content was 45.6mg·L-1) and hypoxia after algae cell decomposed. The average net photosynthesis rate, leaf transpiration rate of the treatment 2 reduced to 3.95μmol·(m2·s)-1, 0.088μmol·(m2·s)-1, and only were 0.18 times, 0.11 times of the control group, respectively, at the end of the experiment, the control group were 22μmol·(m2·s)-1, 0.78μmol·(m2·s)-1. Results indicated the algae bloom together had the irreversible damage to the aquatic plants. Also it was found large amounts of new roots and the old roots were dead in the treatment 1, but roots were all died in the treatment 2, and leaves were yellow and withered. Experiment results manifested that the serious environment caused by the algae blooms together was the main reason of the death of aquatic plants during the summer. So in the practice of ecological restoration, it should avoid the harm to the plant after the algae bloom cells gathered and decomposed, so as to play the purification function of the plant in the ecological rehabilitation project. |
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