北京城市叶面尘分布及其对国槐生理和生长的影响机制
文献类型：学位论文
| 作者 | 宝乐 |
| 学位类别 | 博士 |
| 答辩日期 | 2015-05-01 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 马克明 |
| 关键词 | 叶面尘，行道树，重金属，尘量，生理特性，urban dust, street tree, heavy metal, dust load, physiological characteristics |
| 其他题名 | Distribution of urban foliar dust in Beijing and foliar dust impacts on physiological and growth characteristics of Sophora japonica.L |
| 学位专业 | 生态学 |
| 中文摘要 | 本研究以国槐为研究对象，通过野外调查采样和温室育苗人工滞尘的方法，研究了城市叶面尘对植物生理和生长的影响。在城市叶面尘量方面，首先，采样调查获得了北京市国槐行道树叶面尘空间分布特征；其次，分析了城市叶面尘量和国槐行道树生理特性以及叶重金属的关系；再次，人工滞尘模拟了四个尘量影响，探讨了生理和生长特性受尘影响的尘量阈值。在城市叶面尘污染物方面，首先，比较了城市叶面尘重金属和树坑土壤重金属对国槐行道树叶重金属以及生理特性的影响；其次，在温室比较了城市尘和壤土对国槐幼苗生理生长特性的影响差异；再次，将尘重金属与国槐幼苗重金属和生理生长特性建立联系。在尘的综合影响方面，研究了城市叶面尘的污染物、尘量、粒径对国槐幼苗生理生长的单独和共同影响。主要结论有以下几个方面： 1、国槐叶面尘量随离城中心距离的增加而增加。在6车道，10车道和12车道的道路上，国槐叶面尘量显著高于庭院树。随着路长面积比的升高，行道树叶面尘量先下降后上升。东方向和西方向的行道树枝叶叶面尘量较高，而北方向和南方向的叶面尘量较低。行道树国槐和庭院树国槐的叶绿素a/b、总叶绿素和细胞膜透性有显著差异。行道树叶Zn、Cu、Mn含量显著高于庭院树。 2、国槐行道树叶重金属含量远小于叶面尘重金属滞留量和土壤重金属含量。叶面尘Zn、Pb和Mn浓度分别与叶Zn、 Pb和Mn浓度显著正相关。叶面尘Cr、Zn、Cu和Mn滞留量与叶Cr、Zn、Cu和Mn浓度显著正相关。土壤Mn浓度与叶Mn浓度显著正相关。叶面尘重金属含量对行道树叶生理特性的解释度大于土壤重金属含量的解释度。行道树叶重金属和生理特性的结果都表明，叶面尘重金属影响大于树坑土壤重金属影响。 3、随着尘量的升高, 叶绿素含量和气体交换参数对数下降。根冠比对数升高，高度生长量线性下降。气体交换参数随滞尘时间幂函数下降，滞尘前期下降速度快，速度逐渐变慢，甚至上升。当尘量超过3.78g/m2时国槐叶绿素含量和光合能力才会被影响。当尘量达到16.64 g/m2时会影响国槐生物量分配。对于滞尘21天的国槐行道树, 目前的北京城市叶面尘量最大值（2.812 g/m2 ）使其净光合速率降低16%；高度生长量下降17%。同时，滞尘带来的叶生物量减少对于行道树可能是一个潜在的风险。使用国槐作为行道树或者其他城市绿地是减缓颗粒物污染的好方法。 4、国槐幼苗的大多数生长特性受尘污染物和尘量的影响。尘成分和尘量显著影响叶 N，根冠比和叶绿素 a/b、ΦPSⅡ和NPQ；尘量显著影响叶C/N，地上生物量，总叶绿素和类胡萝卜素；尘污染物显著影响茎N 和茎 C/N和Fv′/Fm′；尘粒径和尘成分影响Fv/Fm。尘污染物和尘量的影响大于尘粒径的影响。城市尘对植物生长特性比壤土的影响强烈。高尘量增强了城市尘和壤土处理的差异。城市尘Cu、Zn、Cr含量与壤土差异较大，导致了叶Cu 、Zn、Cr含量在城市尘、壤土之间差异较为显著。尘元素含量与国槐幼苗茎叶N、茎叶C/N、根冠比和Fv/Fm显著相关。 |
| 英文摘要 | In order to explore the urban foliar dust impacts on the physiology and growth of plants, Sophora japonica.L was selected for the field survey and greenhouse cultivation. As for dust load impacts of urban foliar dust, firstly, we obtained the distribution characteristics of urban foliar dust in Beijing; secondly, we analyzed the relationship between urban dust load and the physiological characteristics as well as heavy metals of S.japonica leaves; lastly, we explored the threshold amounts of dust load impacts on physiological and growth characteristics through an artificial simulation of four dust loads. As for impacts of pollutants in urban foliar dust, firstly, impacts of heavy metals in the urban foliar dust and the cultivation soil were compared, on leaf heavy metals and physiological characteristics of S.japonica; secondly, we compared the impacts of urban dust and loam on the pysiological and growth characteristics of S.japonica seedling in greenhouse; lastly, we analyzed relationships between the heavy metals in foliar dust and heavy metals as well as physiological characteristics of S.japonica seedlings. As for comprehensive impacts of foliar dust, the individual and interactive influences of urban dust pollutants, load and grain size on the physiological and growth characteristics of S.japonica seedlings were studied. The main conclusions are as follows: 1、Foilar dust load of S.japonica had a trend of increase at urban-rural gradient. Foilar dust load of street trees in 6 lane, 10 lane and 12 lane roads were signicantly higher than that of yard trees. With increase of the road length/area ratio, foliar dust loads declined and rised. Foliar dust loads of east and west branches were higher than those of north and south branches. Chlorophyll a/b , total chlorophyll and membrane permeability of street trees were signicantly higher than those of yard trees. Zn、Cu、Mn contents of street tree leaves were signicantly higher than those of yard trees. 2、Heavy metal contents of S.japonica leaves were much lower than those of foliar dust and cultivation soil. Leaf Zn、Pb and Mn were positively correlated with Zn、Pb and Mn respectively in foilar dust. Leaf Cr、Zn、Cu and Mn were positively correlated with Cr、Zn、Cu and Mn respectively in foilar dust. Leaf Mn was positively correlated with Mn in cultivation soil. The explanation of variation of foliar dust heavy metals was higher than that of cultivation soil heavy metals when explaining physiological characteristics of street trees. Consequences of foliar heavy metals and physiological characteristics of street trees proved that impacts of foliar dust heavy metal were greater than those of cultivation soil. 3、Along with the rising urban dust load, chlorophylls and gas exchange parameters had logarithmic droppings. The root-shoot ratio of biomass logarithmically increased and the height increments had a linear decline. Gas exchange parameters varied with power functions that decreased fast in the initial dusting time and then reduced slowly or even increased. Chlorophyll content and photosynthesis were not influenced at dust loads below 3.78g/m2 ; biomass allocation was not impacted until 16.64g/m2. When dusted with the maximum foliar dust load of Beijing’s street trees for 21 days, photosynthetic performance of S. japonica would decrease by 16%; height increment of S. japonica would decrease by 17%. Leaf biomass decline caused by dust might be a potential risk for street trees. Using plants like S. japonica as street trees or other greenspaces could be a good measure to mitigate PM pollution. 4、Most growth characteristics S. japonica seedlings were influenced by dust pollutants and dust load. Leaf N, root-shoot ratio, chlorophyll a/b, ΦPSⅡ and NPQ were significantly affected by dust pollutants and dust load; leaf C/N, shoot biomass, total chlorophyll and carotenoid were significantly affected by dust load; stem N and stem C/N and Fv′/Fm′ were significantly affected by dust pollutants; dust grain size affected Fv/Fm significantly. The influences of dust pollutants and dust load were stronger than those of dust grain size. Urban dust influenced growth characteristics more seriously than loam. Higher dust load could make the differences between urban dust and loam treatments greater. There were obvious differences between urban dust and loam, which caused the leaf Cu、Zn and Cr differences between urban dust and loam treatments. Dust elements well related to the shoot N, shoot C/N ,root-shoot ratio and Fv/Fm of S. japonica seedlings. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/34112]  |
| 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 | 宝乐. 北京城市叶面尘分布及其对国槐生理和生长的影响机制[D]. 北京. 中国科学院研究生院. 2015. |
入库方式： OAI收割
来源：生态环境研究中心
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