31种园林植物对重金属的富集研究

采集南京市不同功能区的土壤和31种园林植物,分析了Cd、Cr、Cu、Pb和Zn在土壤和植物中的含量,计算了31种园林植物不同器官的重金属富集系数。结果表明,南京市各功能区均不同程度的有重金属累积现象,表现为复合污染。在研究的31种园林植物中,黑松、国槐和杜鹃对Cd、Cu和Zn污染土壤有较强的修复能力;雪松和南天竹对Cd和Zn污染土壤有较强修复能力;栾树和宽叶十大功劳对Cd和Zn污染土壤有较强修复能力。另外,南天竹、桂花、红花继木、侧柏、法国冬青和杜鹃对Pb污染土壤有较强的修复能力;桂花、侧柏、梧桐、马褂木、法国冬青和宽叶十大功劳对Cu污染土壤有较强的修复能力;黄杨对Cr污染土壤等有较强的修复能力。对Zn污染土壤修复的园林植物较多,有水杉、香樟、龙柏、悬铃木、女贞、夹竹桃、黄杨、紫叶李、侧柏、柳杉、马褂木、法国冬青、垂柳、加拿大杨和栾树。特别值得注意的是宽叶十大功劳的根、茎、叶对Zn的富集系数分别为2.04、0.84和1.73,同时对土壤Cd也有较强富集能力,是理想的修复城市Cd、Zn复合污染土壤的园林植物。

Accumulation Research of 31 Species of Ornamental Plants on Heavy Metal

31 species of ornamental plants accompanied by in situ soil were sampled in different land-use zones in Nanjing,and Cd、Cr、Cu、Pb and Zn in the plants and soils were determined,and the accumulation coefficients of the determined heavy metals of differet organs in 31 species of ornamental plants were calculated.The results showed that the soils of different land-use zones in Nanjing were polluted by heavy metal.Pinus thunbergii Parl.,Sophora japonica Linn.and Rhododendron simsii Planch had high enriching abilities to Cd,Cu and Zn in 31 species of ornamental plants.Cedrus deodara（Roxb.） G.Don and Nandina domestica Thunb.had high enriching abilities to Cd and Pb.Koelreuteria paniculata and Mahoniabealei（Fort.Carr.） had high enriching abilities to Cd and Zn.Thoses ornamental plants have the properties to restore soil polluted by combined heavy metal.At the same time,Nandina domestica Thunb.,Osmanthus fragrans,Lorpetalum chindensevar.rubrum,Platycladus orientalis（Linn.） Franco,Viburnum odoratissimum Ker.,and Rhododendron simsii Planch to Pb polluted soil,Osmanthus fragrans,Platycladus orientalis（Linn.） Franco,Firmiana platanifolia（Linn.f.） Marsili,Liriodendron chinense（Hemsl） Sarg.,Viburnum odoratissimum Ker.and Mahoniabealei（Fort.Carr.） to Cu polluted soil,and Buxus sinica（Rehd.et Wils.） Cheng to Cr polluted soil all had high purification abilities.There were many determined ornamental plants such as Metasequoia glyptostrboides,Cinnamomum camphora,Juniperus chinensis CV.Kaizuka and so on had high ability to restore Zn polluted soil abilities.It is significant that the accumulation coefficients to Zn in roots,stems and leaves of Mahoniabealei（Fort.Carr.） were 2.04,0.84 and 1.73 respectively.Mahoniabealei（Fort.Carr.） is very useful in restoration of Cd and Zn polluted soil in the city.