北京常见树种滞留大气颗粒物能力研究

Atmospheric Particle Retaining Capability of Common Garden Plant Species in Beijing

为研究北京常见树种滞留颗粒物的能力,以北京20种常见树种及部分2~3年生苗为试材,通过叶片采样、电镜扫描、能谱分析、图像处理、脯氨酸含量测定等方法,对常见树种的滞尘能力进行系统分析。结果表明:2~3年生苗滞尘效果方面存在一定的差异,滞尘能力较高的为麦李和毛樱桃,较差的为接骨木、香椿和毛桃;由于实际造林立地条件的不同,不同立地条件下树种滞尘能力不同,该差异与其叶表面微形态结构密切相关,不同树种叶表面形成不同的沟槽、突起、小室,沟槽越密集,越深,越有利于滞留大气颗粒物;单位面积滞尘量较高的树种其脯氨酸含量也较高;能谱分析表明,树种所附着的颗粒物为PM2.5和PM10的尘土,部分元素来自于汽车尾气的排放。

To study the particulate matter retaining capability of the common tree species in Beijing,20 kinds of tree species and 2 to 3 years seedlings in Beijing were regarded as test materials.Via leaf sampling,electron microscope scanning,energy spectrum analysis,image processing,proline content measurement,a system analysis was carried out to the dust retaining capability of the common tree species.The results showed that there were some differences in the dust removal effect of the 2 to 3 years seedlings,Cerasus glandulosa and Cerasus tomentosa possessed higher dust retaining capability,while the dust retaining capability of the Sambucus williamsii Hance,Toona sinensis and Amygdalus persica was poor.The dust retaining capability of the tree species varied from the different conditions of actual afforestation site,and furthermore,the difference was closely related to the microstructure feature on the surface of the leaves.Different grooves,protuberances and cavities formed on the leaf surface of the various tree species.If the groove was more intensive and deeper,it was more beneficial for the detention of atmospheric particulates,and moreover,for the variety of trees with high unit area dust removal quantity,the proline content was higher.The energy spectrum analysis showed that the particulate matters captured by the tree species were PM_（2.5） and PM_（10） dust,and partial elements were from the emission of automobile exhaust.