18种绿化树木叶片铅、镉、氯、硫含量的比较

为了探究绿化树木叶片富集大气污染物的差异性，对新乡市 18种道路绿化树木叶片铅、镉、氯和硫的含量进行测定分析。结果表明:绿化树木对大气污染物具有一定的吸收净化能力，并依污染元素和植物的不同具有明显差异；同种园林植物叶片累积4种污染元素的含量不同，总体来说对氯和硫的累积能力大于铅和镉；对铅累积量高的树木有枇杷、榆树和杨树；对镉累积量高的有枇杷、广玉兰、毛泡桐和杨树；对氯累积量高的有卫矛、大叶黄杨、杨树、榆树和臭椿；对硫累积量相对较高的有杨树、卫矛、毛泡桐和珊瑚树。运用隶属函数法对 18种绿化树木叶片污染元素含量进行归类，杨树和枇杷归为第1类，卫矛、大叶黄杨、毛泡桐、广玉兰、榆树和栾树为第2类，银杏、珊瑚树、臭椿、悬铃木、构树、鸡爪槭、海桐、白蜡、国槐和凤尾兰归为第3类。

Comparison of the Contents of Pd,Cd, Cl and S in the Leaves of 18 Greening Tree Species

In order to reveal the differences in the capabilities of the greening tree leaves to absorb atmospheric pollutants, such as lead, cadmium, chlorine, and sulfur, 18 greening tree species occurring in Xinxiang, Henan Province were selected for the study. The results indicated that depending on the types of pollutants and tree species, the trees tested could absorb atmospheric pollutants to different extents. Differences in the capabilities of absorbing 4 pollution elements were significant, and generally, the capacities for the trees to accumulate chlorine and sulfur were higher than lead and cadmium. Higher lead contents were found in the leaves of Eriobotrya japonica, Ulmus pumila and Populus deltoides, while E. japonica, Magnolia grandiflora, Paulownia and Populus deltoides demonstrated high cadmium accumulation capability, and; Euonymus alatus, Buxus megistophylla, Populus deltoides, U. pumila and Ailanthus altissima could enrich chlorine; and Populus deltoides, E. alatus, Paulownia and Viburnum awabuki were found to enrich sulfur. Tree species tested were grouped into three categories by subordinate function based on their capabilities to absorb pollutants. Populus deltoides and E. japonica were in the first category, the second category included E. alatus, B. megistophylla, Paulownia, M. grandiflora, U. pumila and Koelreuteriapaniculata. Ginkgo biloba, V. awabuki, A. altissima, Platanus hispanica, Broussonetia papyrifera, Acer palmatum, Pittosporum tobira , Fraxinus chinensis, Sophora japonica and Yucca gloriosa were classified to the third category.