Comparison of the Foliage Chlorine Contents in 26 Afforestation Trees

The afforest tree is an important supporter in environmental improvement and whose foliage is an absorber of atmospheric pollutants,26 afforestation trees were chosen indifferent seasons and functional areas in the year of 2011 in Xinxiang,and the foliage chlorine contents ofdifferent trees was mensurated.The results indicated that the chlorine contents of the afforest trees' leaves increased according to seasonal variation of spring,summer and autumn.In comparison with clean areas,the chlorine contents of all the trees were relatively high in severely polluted industial areas.The foliage chlorine contents ofdifferent afforestation trees could be classified by K-Means Cluster,Buxus megistophylla,Syringa oblate,Euonymus alatus,Populus canadensis,Ligustrun lucidum,were classified as the first category and their chlorine contents were relatively high.The second category included Ailanthus altissima,Ulmus pumila,Acer elegantulum Fanget,Amygdalus triloba,Koelreuteria paniculata,Buxus sinica,Ginkgo biloba and Papermulberry,their chlorine contents were in the medium.The third category included Forsythia suspense,Paulownia,Populus tomentosa,Cercis chinensis,Sophora japonica Linn,Photiniadavidsoniae,Eriobotrya japonica,Magnoliadenudate,Photinia serrulata,Yucca gloriosa,Salix babylonica,Prunus cerasifera and Fraxinus chinensis,their foliage chlorine contents were relatively low.