东北主要绿化树种对大气重金属污染物吸收能力的研究

本文于2003年9月到10月在哈尔滨市主要街道采集和分析主要绿化树种的树叶，研究测定了东北主要的24种乔木树种和6种灌木树种对大气重金属污染物铅、镉、铬、汞的吸收能力。结果表明：绿化树种对铅、镉、铬、汞具有一定的吸收能力，并依污染物和树种的不同而有明显差异；根据不同树种对不同大气重金属污染物吸收量的差异将其各分为三级，其中吸铅量高的树种有白桦、垂枝榆和京桃等；吸镉量高的树种有小黑杨、钻天杨、银中杨和旱柳等；吸铬量高的树种有黄菠萝、紫丁香、旱柳、黑皮油松、红皮云杉、京桃、榆叶梅和糖槭等；吸汞量高的树种有榆叶梅、蒙古栎、旱柳、接骨木、野梨和华北绣线菊等。本研究为在不同大气重金属污染条件下选择不同绿化树种提供了科学依据。表4参11。

Absorption capacity of major urban afforestation species in northeastern China to heavy metal pollutants in the atmosphere

Totally 24 arbor tree species and 6 shrub species were measured on their absorption capacities to heavy metal Pb, Cd, Cr, and Hg by collecting and analyzing the leaves of trees along different streets in Harbin city in Sept. to Oct. of 2003. The results showed that all the measured species had certain absorbency to the pollutants (Pb, Cd, Cr and Hg), but there existed significant difference in absorption capacity for different species to different pollutants. The measured tree species were classi-fied into three categories by their absorption quantum of heavy metal pollutants. Among the species measured, Betula platy-phylla, Ulmus pumila var. pendula, and Prunus persica f. rubro-plena had high capacity in absorbing Pb; Populus xiaohei, P. ni-gra var. italica, P. alba P. berolinensis and Salix matsudana had had high capacity in absorbing Cd; Phellodendron amurense, Syringa oblata, Salix matsudana, Pinus tabulaeformis var. mukdensis, Picea koraiensis, Prunus persica f. rubro-plena, P. triloba and Acer negundo, etc. had high capacity in absorption of Cr; Prunus triloba, Quercus mongolica, Salix matsudana, Sambucus williamsii, Pyrus ussuuriensis and Spiraea fritschiana were good at absorption of Hg. This study might offer scientific foundation for selection of urban afforestation species in different polluted conditions caused by heavy metals.