北京市常见落叶树种叶片滞纳空气颗粒物功能

Atmospheric Particle Retaining Function of Common Deciduous Tree Species Leaves in Beijing

为了探求北京市常见落叶乔木树种滞纳空气颗粒物的功能,选取了6种典型落叶乔木树种(杨树、刺槐、栾树、垂柳、元宝枫、银杏),利用空气气溶胶再发生器(QRJZFSQ-I)测定了不同树种单位面积叶片对空气总悬浮颗粒物(TSP)、粗颗粒物和细颗粒物的滞纳量.结果表明:16个树种的叶片对不同粒径空气颗粒物均能起到一定的滞纳作用,且不同树种滞纳量表现出较大差异,栾树和刺槐单位面积叶片对不同粒径颗粒物的滞纳量最高,杨树的滞纳量最小;2不同树种单位面积叶片对不同粒径颗粒物的滞纳量并不完全随着取样时间的延长而增加,在雨后8 d和雨后5 d,不同树种单位面积叶片对TSP和粗颗粒物的滞纳量差异较大,但不同树种单位面积叶片对细颗粒物的滞纳量在不同取样时间下没有明显差异.在北京以空气污染的生态治理为目标选择落叶树种时,与银杏、垂柳、元宝枫、杨树相比,应优先选择栾树,其次为刺槐.

In order to explore the atmospheric particle-retaining function of common deciduous tree species leaves in Beijing,six typical tree species( Populus,Robinia pseudoacacia,Koelreuteria paniculata,Salix babylonica,Acer truncatum,Ginkgo biloba) were chosen to measure retaining amount of unit leaf area of air total suspended particles( TSP),coarse particles and fine particulate with aerosol generator( QRJZFSQ-I). The results showed that 1 All six tree species leaves had a certain level of retaining ability to different sizes of atmospheric particles,and different species exhibited some differences. For different sizes of atmospheric particle,retaining amounts of unit leaf area were higher in Koelreuteria paniculata and Robinia pseudoacacia than those of other four species,and the amount of Populus was the lowest among all tree species; 2 The retaining amount of unit leaf area for different tree species was not entirely increased with sampling time. The retaining amounts of TSP and coarse particles for all tree species on the eighth day after rain were significantly higher than those on the fifth day after rain,however,the retaining amount of fine particles was not significantly different under different sampling times. In order to select deciduous tree species for ecological management of air pollution in Beijing,Koelreuteria paniculata should be considered as the priority,followed by Robinia pseudoacacia,compared with Ginkgo biloba,Salix babylonica,Acer truncatum and Populus.