Study On Environmental Effects Of The Main Road Domain Plants In Nanjing

In order to research environmental effects of the main road domain plants in Nanjing,thispaper takes Nanjing city as the sample district.The portable monitor of heavy metals in soil andICP instrument were used for measuring the contents of heavy metals(Cr,Cd,Ni,Pb,Zn) inroadside topsoil and10kinds of major road domain plants’ leaves and stems samples from fivetypical functional areas,and using Excel,SPSS19.0software for statistical analysis of testdata.Evaluate the roadside topsoil heavy metals pollution of each functional area in Nanjing byusing Single factor index,Nemerow pollution index and Potential ecological risk index.Throughthe research on heavy metal contents of10kinds common road plants,the capacity of absorptionand difference between plants’ leaves and stems in varied pollutant environment werecompared;the situations of air pollution in various functional areas were evaluated;and at thesame time with K-average clustering analysis method the stronger absorption of heavymetals(Cr,Cd,Ni,Pb,Zn) in plants were selected;and finally the coefficient of heavy metals amongroadside topsoil in different functional areas,between the leaves and stems from differentplants,the plants and topsoils were studied by Pearson correlation analysis.To provide theoreticalbasis for the selection of road domain pollution resistant plants.The specific conclusions are asfollows:1The evaluation results of Single pollution index show that all functional areas werepolluted differently.The Nemerow comprehensive pollution index and Potential ecological riskindex from high to low were both Transport hub area>Industrial area>Science and livingarea>Business area>Scenic area.The integrated pollution of five functional areas were allsevere,and the ecological risk of Cr,Ni,Pb,Zn were all slight, except the degree of Cd wasextremely strong.Correlation analysis of heavy metals varied significantly among all thefunctional areas, suggesting that the sources of pollution are different.2According to the difference of plants and organs,10kinds of the road domain plants’ leavesand stems are all have certain ability of accumulation and absorption with heavymetals(Cr,Cd,Ni,Pb,Zn).The absorption of plants’ leaves and stems from five functional areasgenerally follows the law of the highest Zn uptake,the lowest Cd uptake,except of the stem ofEuonymus Japonicus cv.Aureo-ma in Business area with the highest Pb uptake.3Make the Scenic area an a control area,judge the atmospheric pollution level of the otherfour functional areas comprehensively,and the results show that the Science and Living area waspolluted moderately by Cr and Ni,Business area and Transport hub area were both pollutedslightly by Ni,Industrial area was polluted moderately by Ni,Business area was polluted slightly by Pb,Science and Living area was polluted slightly by Zn,while the remaining are all clean.4The results of K-average cluster analysis showed that the plants with high uptake of Cr areLorpetalum chindensevar.rubrum,Buxus sinica;the plants with high uptake of Cd are Photiniaserrulata,Buxus sinica,Viburnum odoratissimum,Ligustrum lucidum,Fatsia japonica (Thunb)Decne et Planch;the plant with high uptake of Ni is Buxus sinica;the plants with high uptake ofPb are Lorpetalum chindensevar.rubrum,Buxus megistophylla,Buxus sinica,Ligustrumlucidum;the plant with high uptake of Zn is Ligustrum lucidum.5The correlation analysis results show that the difference of correlation in plants’ leaves andstems among different functional areas is large.The contents of heavy metals in plants’ leaves andstems from different functional areas were all correlated significantly,and the correlationcoefficient of Industrial area is the highest while the Science and Living area is the lowest.Thisshowed that the Industrial plants’ leaves and stems are likely to come from the same pollutionpathway,while the Science and Living area are influenced by many factors.The difference ofcorrelation between plants and topsoils from different functional areas varied greatly.Ingeneral,the contents of heavy metals from five functional areas and corresponding topsoilspresented different degree of positive correlation and negative correlation,which showed thatthere is no necessary link on the aggregate heavy metals between each other,but may exist a verycomplex synergy and antagonistic relationship between them.