益阳市主要行道树叶片重金属富集状况及污染评价

Heavy metal accumulation and pollution evaluation of main street tree leaves in Yiyang City

以益阳市街道分布面积较广的几种行道树作为研究对象,通过测定其叶片和根际土壤重金属含量对环境土壤和大气质量进行评价,探讨植物叶片重金属含量与益阳市大气污染之间的关系.结果表明:街道区植物叶片中的Cr、Pb含量较高,清洁对照区的植物叶片重金属含量均较低;益阳市行道树根际土壤单因子指数显示Cr、Pb污染等级均为清洁,Cu污染等级为清洁~中度污染;地积累指数显示污染等级中Cr为无污染,Pb为无污染~轻度污染,Cu为无污染~中度污染;益阳市主要行道树重金属含量对应的大气污染评价为无污染~轻度污染,这表明该市主要植物受到大气重金属的污染较小.

Taking several kinds of wide distribution roadside trees in Yiyang City as the research objects,contents of heavy metals in the leaves and the rhizosphere of the trees were studied and the soil and air quality were evaluated.The relationship between the content of heavy metals in leaves of plants and air environment pollution was discussed.The results showed that the contents of Cr and Pb in the leaves of plants in the street area were higher,and the contents of heavy metals in the leaves of plants in the clean control area were lower;the single factor index of the rhizosphere soil of street trees in Yiyang City showed that the pollution levels of Cr and Pb were clean,and the pollution levels of Cu were clean~moderate pollution;the land accumulation index showed that Cr was non-pollution,Pb was non-pollution~mild pollution,and Cu was non-pollution~moderate pollution.The evaluation of the air pollution corresponding to the heavy metal content of the main street trees in Yiyang City is non-pollution~mild pollution,which indicates that the main plants in the city are less polluted by atmospheric heavy metals.