基于重金属积累特征的城市绿化树种配置模式研究

用原子吸收法测定了芜湖市城区干道土壤与植物重金属(Cd、Pb、Zn、Cu)的平均含量,并分析了植物的重金属富集系数.结果表明:芜湖市城区已受到重金属的不同程度污染,土壤重金属元素的污染程度以Cd、Cu为最高,其次为Pb,污染程度最轻的为Zn.各绿化树种对重金属的积累特征表现为器官差异和金属差异性,即叶>茎及Cu>Zn>Pb>Cd.就所研究树种的综合富集系数而言,红枫是提取城市生态系统中重金属较为理想的树种之一.在重金属Cd污染较严重的区域宜栽种红枫、鸡爪槭、桂花等;Pb污染区可选择栽种红枫、鸡爪槭、银杏;Cu污染区可栽种红枫、女贞;Zn污染区可以选择龙柏和黄杨等.

A Preliminary Investigation into the Arrangement Pattern of Tree Species Based on Heavy-Metal-Accumulation Ability

The contents of heavy metals including Cd,Pb,Zn and Cu in soils and plants sampled in three throughways in Wuhu,Anhui province,were determined with Atom-absorption spectrophotometer.The heavy metal accumulation coefficients of different plant species were also analyzed.The results suggested that soil in Wuhu urban area has been contaminated to a certain degree.In particular,the soil was polluted mainly by Cd and Cu,followed by Pb and Zn.There are plant organs-and heavy metal-specific differences in the accumulation ability of different greening tree species,viz.root> stem and Cu>Zn>Pb>Cd.As far as the individual and integrated accumulation coefficients were concerned,Acer atropurpureum is an ideal plant species for phytoextraction from polluted urban soil.It is recommended to grow A.atropurpureum,Acer rubrum and Osmamthus fragrans in soils contaminated heavily by Cd,to grow A.atropurpureum,Acer rubrum and Ginkgo biloba in soils contaminated heavily by Pb,to grow A.atropurpureum and Ligustrum Lucidum in soils contaminated by Cu and to grow Abina chinensis and Buxus sinica in soils contaminated by Zn.