氮沉降、干旱胁迫下臭氧对杨树光合生理及生长的影响
文献类型：学位论文
| 作者 | 辛月 |
| 学位类别 | 硕士 |
| 答辩日期 | 2016-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 冯兆忠 |
| 关键词 | 臭氧，杨树，光合，生物量 ozone, Populus cathayana, photosynthesis, biomass |
| 其他题名 | Effects of ozone on the photosynthetic physiology and growth of Populus cathayana under nitrogen deposition or drought stress |
| 学位专业 | 生态学 |
| 中文摘要 | 近地层臭氧（O3）既是一种光化学二次污染物，也是重要的温室气体之一。随着工业化与城市化的快速发展，O3浓度不断升高，对植物产生氧化毒害，严重威胁森林生态系统健康发展。目前，国内关于O3对树木影响的研究主要是针对亚热带常绿树种和温带城市绿化树种，而对我国广泛分布的落叶树种杨树为试验对象的研究尚未展开探究。本研究采用田间暴露与开顶式气室熏蒸法，于2015年进行野外试验，主要从光合生理、叶片光合色素、抗性生理、生长以及生物量累积分配等多方面阐述干旱胁迫下施加EDU评价当前环境O3浓度对杨树O3伤害的影响，以及模拟未来O3浓度升高与氮沉降增加对杨树的影响，旨在较全面地探讨杨树对O3浓度升高的响应机制，为全球变化背景下的杨树O3防护提供科学依据。研究结论如下： EDU可有效缓解环境O3对杨树的伤害：提高叶片光合能力，降低膜脂过氧化，促进生长，增加生物量累积等。喷施EDU浓度为450 ppm时，效果最佳。干旱对杨树的光合生理及生长产生了显著负效应，显著降低了杨树的光合作用，从而减少了生物量累积。但干旱并未影响EDU对当前环境O3浓度下杨树的防护作用，这与处理时间以及干旱程度直接相关。 随着O3浓度升高，杨树叶片光合色素含量、净光合速率、电子传递效率等显著降低，并且加剧膜质过氧化，进而导致累积的生物量下降，根冠比显著升高，严重抑制了杨树的生长与生产力。一定范围内的氮沉降量对杨树光合作用以及生物量有正效应。但是，过量的氮沉降对光合作用不利，进一步降低了植物的生物量累积。O3与氮沉降对杨树的光合作用以及生物量的交互作用不显著，这与与实验处理时间、测定气象条件、树种的O3敏感性有关。 |
| 英文摘要 | Tropospheric ozone (O3) is not only a photochemical secondary pollutant, but also a significant greenhouse gas. With the rapid development of industrialization and urbanization, the concentration of O3 is rising constantly, which has caused oxidant injury to plants and been a serious threat to the healthy development of the forest ecosystem. However, so far the domestic studies on the effect of O3 on trees are mainly aimed at subtropical evergreen tree species and temperate urban greening tree species. Little information is available concerning the O3 effects on the growth and physiology of deciduous tree species of poplar which is widely distributed in China. This research adopted the method of total field exposure and the open top chambers in 2015. The objectives of the study were to explore whether drought stress affects the protection of EDU to the poplar under the current ambient ozone concentration and to investigate the combined effects of the future elevated O3 concentration and nitrogen deposition on the poplar species by measuring photosynthesis, leaf photosynthetic pigments, antioxidant system, growth and biomass accumulation. The comprehensive mechanism of poplar response to elevated O3 concentration can provide scientific basis for the O3 protection of poplars under the background of global change. The final conclusions of the study were shown as follows. EDU could effectively alleviate the damage on poplar by improving photosynthetic capacity, reducing the membrane lipid peroxidation, promoting growth and the biomass accumulation. Compared with control, 450 ppm EDU showed the largest effects on plants. Drought had a significant negative effect on the photosynthetic physiology and growth of Populus cathayana. It significantly reduced the photosynthesis, thereby reducing the biomass accumulation. However,drought didn’t significantly affect the protection of EDU to P. cathayana under the current ambient O3 concentration. This was directly related to the processing time and degree of drought. With the elevated O3 concentration, the leaf photosynthetic pigment contents, net photosynthetic rate and electron transfer efficiency of P. cathayana was significantly reduced and membrane lipid peroxidation was more prominent. Besides, it led to the decrease of the biomass accumulation and the increase of root-shoot ratio significantly, which hold back the growth and productivity. A certain range of nitrogen deposition on photosynthesis and biomass had a positive effect. However, excessive nitrogen deposition decreased photosynthesis and then reduced the biomass accumulation. But the interaction of elevated O3 and nitrogen deposition had no significant influence on photosynthesis and biomass, which related to the longth of experimental time, the meteorological conditions or associated tree species diversity. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/37027]  |
| 专题 | 生态环境研究中心_城市与区域生态国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 辛月. 氮沉降、干旱胁迫下臭氧对杨树光合生理及生长的影响[D]. 北京. 中国科学院研究生院. 2016. |
入库方式： OAI收割
来源：生态环境研究中心
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