北京市主要路旁绿化灌木中重金属元素分布特征

Accumulation of Heavy Metal Elements in Urban Roadside Shrubs in Beijing

分析了北京市7种主要路旁绿化灌木的重金属元素质量分数。结果表明:7种优势植物对重金属元素有不同程度的积累,但积累量均未达到超积累植物所规定的临界含量。小叶女贞和紫叶小檗对重金属的转运能力(向地上部分)较强,对重金属污染土壤有一定的修复潜力。植物各器官对重金属元素的吸收受土壤中重金属元素质量分数的影响。从对重金属的富集吸收能力来看,根最强,茎次之,叶最弱,趋势明显。小叶女贞、紫叶小檗、小叶黄杨对重金属的富集能力都较强,是对抗重金属污染的最佳选择。

An experiment was conducted to study the contents of five heavy metal dements in seven species of urban roadside shrubs in Beijing. Different degrees of accumulation of heavy metal elements were found in these seven predominant plant species, and the contents of Cu, Zn, Cr, Pb and Ni in these plants did not reach the critical contents of hyperaccumulator. Ligustrum quihoui and Berberis thunbergii cv. atropurpurea had higher abilities to carry heavy metal elements from root to up-ground parts compared with other plant species, indicating that the two species can remediate contaminated soil to a certain degree. The accumulation of heavy metal elements in urban roadside shrubs was influenced by the heavy metal dement contents in the soil. Result shows that root accumulates most of heavy metal dements, caudex takes the second place and leaf accumulates the least. L quihoui, Buxus microphylla var. sinica and B. thunbergii cv. atropurpurea have stronger abilities to accumulate heavy metal dements; therefore, they are good plant species for resisting heavy metal contamination.