南京市城乡公路蜀桧叶片中金属元素和氮、硫含量分析

Concentrations of metallic elements,N and S in Sabina chinensis cv.pyramidalis leaves along urban-rural roadways of Nanjing city.

通过对南京市城乡公路(城市干线、绕城公路和城郊公路)和相对清洁对照点植物园环境中土壤和蜀桧叶片中金属元素和N、S含量的测定,研究了环境元素在土壤植物大气之间的转移.结果表明,在城市干线、绕城公路和城郊公路环境中生长的蜀桧叶片中,10种金属元素中有Al、Fe、Mo、Zn、Cd、Pb、As和Cr含量明显超过对照点,其中尤以Al、Fe、Mo和Zn最显著.公路环境蜀桧叶片中,Fe、Zn和As在土壤植物间的相关性显著,说明蜀桧可能是Fe、Zn和As的良好指示植物;蜀桧叶片中Al、Mo、Cu、Pb、Cd和Cr在土壤植物间相关性不显著,说明公路环境中其含量较高可能是受大气污染的影响.城市干线和绕城公路蜀桧叶片中的N和S含量高于对照点,而城郊公路则接近对照.相关分析表明,公路土壤含N量在土壤植物间呈负相关,低于对照,含S量在土壤植物间呈正相关,高于对照.因此,公路环境蜀桧叶片中较高的N含量可能是汽车尾气排放的NOx影响的结果,而较高的S含量则主要来自土壤.

This paper measured the concentrations of metallic elements,N and S in soils and Sabina chinensis cv.pyramidalis leaves along the urban-rural roadways (urban trunk roads,belt highway,and suburban roads) of Nanjing city,with botanical garden as un-traffic impacted reference site,and discussed the transfer of test elements among atmosphere,plant and soil,as well as the impact of traffic- related pollution.The results showed that the concentrations of Al,Fe,Mo,Zn,Cd,Pb,As and Cr in Sabina chinensis leaves were significantly higher along urban-rural roadways than at reference site,being most remarkable for Al,Fe,Mo and Zn.The positive correlations between soil and Sabina chinensis leaf Fe,Zn and As concentrations in road environment indicated that Sabina chinensis might be a good indicator plant of soil Fe,Zn and As.The correlations between soil and plant leaf Al,Mo,Cu,Pb,Cd and Cr concentrations were not remarkable,and thus,their high concentrations in Sabina chinensis leaf in road environment might be caused by air pollution.The concentrations of N and S in Sabina chinensis leaf were higher along urban trunk roads and belt highway than at reference site,while those along suburban roads were similar to the reference.There was a negative correlation between soil and plant leaf N,and a positive correlation between soil and plant leaf S.The N content in roadside soil was lower,while the S content was higher than the reference,indicating that the higher Sabina chinensis leaf N content in road environment might be caused by the NO x from exhaust gas emission,and the higher leaf S content should be come from soil.