【作者】 杜忠；

【导师】 陶玲；

【作者基本信息】 兰州交通大学 ， 环境科学， 2007， 硕士

【摘要】 随着兰州市社会经济持续快速的增长和市民生活水平的提高，兰州市的大气污染越来越严重，严重地干扰了市民的生活，成为制约城市经济发展的重要因素。在各种污染物中，SO₂和灰尘是兰州市主要污染物。利用城市绿化树种对大气污染物的吸附、吸收、转移等净化能力，来治理大气污染尤其是近地表大气的混合污染是近年来国际上正在加强研究和迅速发展的前沿性新课题。为了筛选出大气污染的抗性树种种类和敏感监测树种种类，选择兰州市的主要绿化树种为研究对象，对绿化树种的叶绿素、脯氨酸、可溶性糖、pH值进行了测定，并且运用statistica 6.0软件进行分析，找出污染大气污染程度和指标变化之间的关系。本实验共分为两部分。第一部分为室内实验：选择兰州市的主要绿化树种——小叶黄杨、臭椿、圆柏、松树、毛白杨、国槐为研究对象，进行SO₂静态人工熏气实验。然后观察树种在不同熏气浓度下形态症状的变化，测定各个树种生理指标（如pH值、脯氨酸、可溶性糖、叶绿素）的变化，进而推断各树种的抗污染能力的大小。实验结果表明：在SO₂熏气的条件下，各个绿化树种不管是形态症状还是生理指标都表现出了很大的差异性。通过树种的形态症状的变化可以推断，臭椿、小叶黄杨、毛白杨是SO₂很好的抗污染树种，国槐是SO₂抗性中等的树种，圆柏、雪松是SO₂的指示性树种。对生理指标进行线性回归，推断叶片中的脯氨酸含量与熏气浓度呈显著性的正相关，而叶绿素总含量则与熏气浓度成显著性的负相关；6种绿化树种的抗污染能力的大小为：毛白杨＞小叶黄杨＞臭椿＞国槐＞圆柏＞雪松。根据抗污染能力的大小，绿化树种的可以分为3大类：强抗污染能力树种、中等抗污染能力树种、指示性树种。其中：毛白杨、小叶黄杨、臭椿属于强抗污染能力树种：国槐属于中等抗污染能力树种；圆柏、雪松属于大气污染的指示性树种。通过人工滞尘实验，测出树种的滞尘量，确定树种滞尘能力，研究表明毛白杨和臭椿因表面有绒毛，有利于粉尘降落，是好的城市绿化滞尘树种。熏气实验中树种对污染物抗性程度的确定是建立在不同树种对单种污染物反应的基础上，被实际野外栽培时，则面临着多种混合污染物的共同侵扰，于是进行第二部分的室外实验。在兰州市选择大气污染典型污染区（兰炼厂区、兰化厂区）、交通枢纽（西站，西关）、一般污染区（兰州交通大学）和清洁对照区（兴隆山）作为研究区，通过现场大气污染指标的定位观测，以兰州市主要绿化树种（杨树、小叶黄杨、椿树、国槐、圆柏）为研究对象，采集样品带回实验室测定各项生理指标（叶绿素、脯氨酸、可溶性糖、pH值）：测定分析兰州市主要大气污染源区的污染组分及程度，确定不同绿化树种对兰州市大气污染的耐受程度，并进行综合评价。结果表明：同一树种在不同污染区的各项生理指标含量不同，存在显著性的差异，同一污染区的各种绿化树种的生理指标含量也存在显著性的差异。5种树种的抗污染能力为：杨树＞小叶黄杨＞椿树＞国槐＞圆柏，兰州主要污染区的污染程度为：兰炼厂区＞兰化厂区＞橡胶厂＞西关＞西站＞交大＞兴隆山。研究结果可以为兰州市的大气污染治理提供理论和实践依据。更多还原

【Abstract】 With the rapid development of socio-economic and the improvement of the living standards, the air pollution of Lanzhou city is becoming worse and worse. So it becomes the most important factor that disturbs the people’s life and restricts the development of the economic. In all kinds of pollutants, SO₂ and dust are becoming the major pollutants of Lanzhou city. Using the urban greening tree species to absorb the air pollutants is a popular method. And the method is developing very rapidly and has become the foreland item. In order to screen out resistant tree species and sensitive monitoring plant species, five kinds of urban greening tree species are tested, and the chlorophyll contents, soluble sugar contents, proline contents are measured. Then the data is analyzed by statistica 6.0 software.The experiment is divided into two parts. The First part is performed in inner house. The main urban greening tree species, for example, Ailanthus altissima, Euonymus japonicus, Populus tomentosa, Sabina chinensis, Cedrus deodara, Sorphora japonica are selected and placed in SO₂ pollution. Then the morphological symptoms change and the physiological indexes are observed. Resistant degree of plant upon sulfur dioxide pollution is estimated. The experiment shows, not only the morphological symptoms, but also the physiological indexes are all changed significantly in the SO₂ fumigation. Though the morphological symptoms change, it shows that Ailanthus altissima, Euonymus japonicus, Populus tomentosa are good SO₂ absorption tree species. Sorphora japonica has a mean sensitivity to SO₂. Sabina chinensis and Cedrus deodara are very sensible to SO₂ pollution, and both of them can be used as the indicators of SO₂ pollution. Though the physiological indexes change, it shows that the proline contents have a significant positive correlation with the SO₂ concentration, but the chlorophyll contents have a significant negative correlation with the SO₂ concentration. The sequence of pollution tolerance ability can be ranked as: Populus tomentosa, Euonymus japonicus, Ailanthus altissima, Sorphora japonica, Sabina chinensis, Cedrus deodara. All the six tree species are divided into three categories: good SO₂ absorption tree species such as Ailanthus altissima, Euonymus japonicus, Populus tomentosa, mean sensitivity to SO₂ pollution such as Sorphora japonica, sensible to SO₂ pollution such as Sabina chinensis and Cedrus deodara. After the dust detetion test, Populus tomentosa and Ailanthus altissima are good dust detention urban greening tree species.The resistance of the urban greening tree species to SO₂ pollution is tested under single SO₂ pollution fumigation, so the result may not be suitable for the natural condition. So the following outside experiment is carried out. Four categories functional areas are screened out, for example, the representative pollution area, traffic hinge pollution area, normal pollution area, cleanness area. In the five sorts of areas, five common urban greening tree species are chosen. And the ingredients of the air are measured. The samples of the urban greening tree species are carried to the lab and are tested.The experiment shows that, the physiological indexes are different from each other, moreover have reached the significant positive or negative correlation. And in the same place, the indexes are also very different. The sequence of pollution tolerance ability can be ranked as: poplar, Buxus microphylla, Ailanthus altissima, Sorphora japonica, Sabina chinensis. The pollution degree of the seven tested sites in Lanzhou can be ranked as: The oil refining plant, the chemical plant, the rubber plant, xiguan station, xizhan station, Lanzhou jiaotong university, xinglongshan mountain. The experiment can offer theories and practices for the air pollution management in Lanzhou city.更多还原