行道灌木在城市交通环境下的生理响应

Physiological Response of Roadside Shrubs in the Urban Traffic Environment

为筛选适宜的行道灌木,提高道路交通环境质量,选择连云港市区常见的7种行道灌木为研究对象,通过转盘处、交通主干道和相对清洁区的比较,监测了树叶中重金属(Cu、Pb、Zn、Cr、Cd)的含量,脯氨酸、丙二醛和可溶性蛋白等生理指标,同时研究了pH、电导率和树叶表面气孔的变化。结果表明:随着交通密度变大,重金属含量增大,pH变小,电导率变大;在环境污染的逆境下,植物通过增加脯氨酸和蛋白质含量,降低丙二醛浓度来适应逆境;树叶气孔数目和结构的变化随着树种的不一表现出不同的变化。不同的灌木对重金属的吸附能力和环境适应力不一,综合比较石楠(Photinia serrulata Lindl.)、冬青(Ilexchinensis Sims)、海桐(Pittosporum tobira(Thumb.)Ait.)都是较好的行道灌木。

In order to select the appropriate roadside shrubs and improve the environmental quality,samples of 7 species of roadside shrubs,commonly planted in the urban traffic environment of Lianyungan city,were taken in the crossroads,traffic artery and comparatively unpolluted areas far from motor traffic.The contents of heavy metals such as Cu,Pb,Zn,Cr and Cd,physiological indexes such as proline,MDA,soluble protein,pH,electric conductivity and stomatal number in the leaves of the samples were analyzed to reveal the effect of urban traffic environment on roadside shrubs.The results indicated that the contents of heavy metals increased,pH decreased,and the electric conductivity enlarged as the traffic density was larger.The content of proline and soluble protein were heighten and that of MDA was reduced in order to improve the adversity ability.Stomatal number and structure were different for different species.The absorption ability of heavy metals and adaptive capacity to environment were different for the shrubs,overall,heather,holly and pittosporum were the best roadside shrubs for city traffic mainline in this study.