北京4个常见树种空气颗粒物滞留能力研究

以北京市4个常见绿化树种为研究对象，采用水洗称重法研究各树种对PM_＞10（粒径>10 μm的颗粒物）、PM_2.5~10（粒径＞2.5 μm且≤10 μm的颗粒物）和PM_2.5（粒径≤2.5 μm的颗粒物）的滞留能力，并采用扫描电镜对各树种叶片表面特征进行观测。结果表明，各树种颗粒物滞留能力为油松＞侧柏＞核桃＞银杏，针叶树种的颗粒物滞留能力较强；对于PM_＞10和PM_2.5~10粒径范围较大的颗粒物而言，道路边叶片的滞留量明显高于距离路边较远的叶片，对于PM_2.5，道路边和植物园内叶片的颗粒物滞留量变化并不显著；与蜡质层和角质层的形态相比，气孔的分布对叶片颗粒物滞留能力的影响更大。

Research of PM-capturing Capability of Four Common Tree Species in Beijing

In this paper,particulate-capturing (PM-capturing) capability of four common tree species in Beijing were studied.Weighing method was used to identify the capturing capability of PM_>10(diameter>10 μm),PM_2.5-10(diameter>2.5 μm and diameter≤10 μm) and PM_2.5 (diameter≤2.5 μm) of different species.Then,the foliage surface characteristics were observed by scanning electron microscopy (SEM).The results showed that the order of PM-capturing capability was Pinus tabulaeformis>Platycladus orientalis>Juglans regia>Ginkgo biloba.In general,the PM-capturing capability of conifer species was higher than broad-leaved species.For PM_>10 and PM_2.5-10,the foliage beside the road captured more particulate than that farther away from the roadside significantly.However,for PM_2.5,the PM-capturing capability had no significant differences between the foliage beside road and in botanical garden.Compared to the morphological feature of waxy and cuticle on the foliage,the stoma distribution had greater influence on PM-capturing capability.