摘要
【目的】高速公路旁绿化植物可吸收汽车排放的重金属污染,研究不同距离、不同树种对重金属的生物积累差异,可为高速公路绿化林带的营建提供理论证据。【方法】分别选取甬台温高速路旁0~5 m和10~60 m处长势一致的桉树、夹竹桃、女贞和香樟作为研究对象,采集叶片和枝条样品测定其中铅(Pb)、镉(Cd)、铬(Cr)元素含量,对结果进行盒状散点呈列和主成分分析。【结果】距离和树种二因素间不存在交互作用,但高速路旁0~5 m内树木枝叶内Pb和Cr含量显著高于10~60 m处结果,平均增量高达160%以上;桉树和香樟叶片中的Pb含量高于夹竹桃和女贞(P=0.000 7),桉树枝条中Pb含量比女贞高92%(P=0.000 4),但是桉树枝条中Cd含量比夹竹桃枝条低80%(P=0.037 1);距离因素的前3个主成分对方差的累积贡献率在71%~75%,树种因素在92%~96%;距离因素中第1主成分主要以枝条中Cd和Cr的积累量为特征,而第2,3主成分主要以枝条中Pb的积累为特征,并且第4主成分特征值与Cd含量呈负相关关系(R=-0.954;P=0.046);树种因素的第1主成分主要以枝叶中Pb的累积为特征,并且其特征值和Cr含量呈正相关关系(R=0.682;P=0.039),当同时考虑第1,2主成分时,桉树和香樟的Pb含量特征值的绝对值较大,而当同时考虑第1,3主成分时,各树种的Cr和Pb含量呈现无规律的均匀分布。【结论】结合高速路旁不同距离处的结果差异及树种间离散性结果的比较,推荐桉树和夹竹桃作为研究区内高速路旁绿化林带营建树种,可更好地吸收高速车辆排放的重金属。
[ Objective ] The pollution of heavy metals emitted from vehicles can be absorbed by ornamental trees along highway. In this paper, the variation of biological accumulation of heavy metals by ornamental trees with different species at different vertical distance to highway was studied to provide reference for the construction of tree belts with phytoremediation opinion. [ Method ] Four ornamental tree species of Eucalyptus robusta, Nerium indicum, Ligustrum lucidum, and Cinnamornum camphora were chosen as object of study, and they were grown at 0 - 5 m and 10 - 60 m away from the Yong-Tai-Wen highway. The leaves and twigs of trees were sampled for determining contents of Pb, Cd and Cr. The measurement data were analyzed with box-whisker scatter distribution and principal components. [ Result ] No interactive effects between distance and tree-species were detected on any heavy metal contents. However, contents of Pb and Cr from trees located at 0 - 5 m away from the highway were higher than those at 10 - 60 m, with more than 160% higher on average. Heavy metal contents were different among tree species. E. robusta and C. camphora had higher content of Pb in leaves than the other two species ( P = O. 000 7 ) , and twig Pb content in E. robusta was 92% higher than that in L. lucidum (P=0. O00 4), but the content was 80% lower than that in N. indicum twig (P =0.037 1). Theaccumulated contribution of the first three principle components (PCs) to variation ranged from 71% -75% in terms of the factor of distance, while that ranged from 92% -96% in terms of the factor of species. As for the distance factor, the 1st PC was characterized by Cd and Cr accumulations in twigs and branches, but the 2nd and 3rd PCs were both characterized by Pb accumulation, while the eigenvalue of 3rd PC was negatively correlated with Cd content (R = - 0. 954 ; P = 0. 046). For the species factor, the 18' PC was characterized by Pb accumulation in leaves, twigs, and branches, whose eigenvalue was positively correlated with Cr content (R = 0. 682 ; P = 0. 039). The absolute values of eigenvalues for Pb content in E. robusta and C. camphora were higher when composing the analysis between the 1st and 2nd PCs, while those for Cr and Pb were evenly distributed with no conclusive data trait. [ Conclusion ] According to differences between distances away from the highway and the scattered results in tree species comparisons, E. robusta and N. indicum are suggested to be proper for the ornamental tree belt construction along the highways in the study area, for the purpose of potential phytoremediation of heavy metals.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2015年第12期17-25,共9页
Scientia Silvae Sinicae
基金
浙江省森林生态科技创新团队项目(2011R50027)
关键词
生物累积
植物修复
盒状散点
主成分分析
bioaccumulation
phytoremediation
box-whisker plots
principal component analysis