乌鲁木齐市快速路域绿化树种对重金属的累积效应及应用潜力

为筛选出适合干旱区交通路域土壤重金属污染修复治理的绿化树种，通过对乌鲁木齐市河滩快速路域绿化树种进行调查，采集路域16种常见绿化树种的不同器官及对应的根际土壤，测定其重金属Pb、Zn、Cd、Cr、Cu和Ni的含量，计算各树种对重金属的富集转运系数。通过聚类分析与隶属函数分析，综合评价各树种对重金属的累积效应，进一步探讨各树种的应用潜力。结果表明，16种绿化植物对各重金属的富集系数（BCF）与转运系数（BTF）整体表现分别为Zn>Cu>Ni>Pb>Cd>Cr，Zn>Cu>Pb>Ni>Cr>Cd，平均BCF为地下部分大于地上部分。综合评价得出，红皮云杉、复叶槭、圆冠榆、樟子松、火炬树对各重金属的富集转运能力相对较强，对复合型重金属污染具有潜在的修复价值，可考虑作为干旱重金属污染区域修复的首选树种；北美海棠、金叶榆、紫叶矮樱、水蜡、白榆、暴马丁香对各类重金属的富集转运能力相对适中，这类树种可优先考虑为交通路域轻、中度重金属污染的预防树种；大叶白蜡、新疆杨、榆叶梅、垂柳对各类重金属的富集转运能力相对较弱，这类树种属于低积累绿化树种，且在干旱区域具有良好的适生性，可以考虑用于轻度污染区域园林观赏树种。研究结果可为干旱区交通路域污染治理提供指导意见。

Cumulative Effect and Application Potential of Greening Tree Species on Heavy Metals Along Urumqi Expressway

In order to screen out the greening tree species suitable for the remediation and treatment of heavy metal pollution in the soils along the traffic roads,an investigation was conducted in the river beach expressway area in Urumqi City,different organs and corresponding rhizosphere soils of 16 common greening tree species in the road area were collected.The contents of heavy metals such as Pb,Zn,Cd,Cr,Cu and Ni were measured.The enrichment and transport coefficients of various tree species for heavy metals were calculated.Through cluster analysis and membership function analysis,the cumulative effect of each tree species on heavy metals was comprehensively evaluated,and the application potential of each tree species was further explored.The results showed that the overall biological concentration factor (BCF) and biological transfer factor (BTF) performance of 16 green plants for each heavy metal was in the order of Zn>Cu>Ni>Pb>Cd>Cr,Zn>Cu>Pb>Ni>Cr>Cd,the average BCF of the underground part was higher than that of the above-ground part.Comprehensive evaluation showed that Picea koraiensis,Acer negundo,Ulmus densa,Pinus sylvestris var.mongolica and Rhus typhina demonstrated relatively strong ability to enrich and transport heavy metals,and had potential remediation value for complex heavy metal pollution,which could be considered the heavy metal remediation tree species in drought areas; Malus sp.,Ulmus pumila‘Jinye’,Prunus×cistena,Ligustrum obtusifolium,Ulmus pumila and Syringa reticulata had relatively moderate enrichment and transportation capabilities for various heavy metals,which could be prioritized along light traffic roads with moderate heavy metal pollution.Fraxinus rhynchophylla,Populus sbolleana,Amygdalus triloba and Salix babylonica had relatively weak ability to enrich and transport various types of heavy metals,which could be the candidates of greening tree species in arid areas with light heavy mental pollution for their good adaptabilities to drought and beautiful tree form.The results of this study are expected to provide guidance for pollution control of traffic roads in arid areas.