北京4个常见树种空气颗粒物滞留能力研究

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

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〉10μm的颗粒物）、PM2.5~10（粒径〉2.5μm且≤10μm的颗粒物）和PM2.5（粒径≤2.5μm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PM2.5~10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PM2.5,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。

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 vm） ,PM2.5-10 （diameter〉2.5 μm and diameter≤10 μm） and PMa5 （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 tabulaeforrnis〉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 PM2.5-10, the foliage beside the road captured more particulate than that farther away from the roadside significantly. However,for PM2.5 ,the PM-capturing capability had no significant differences between the foliage beside road and in botanical garden. Compared to the morpholog- ical feature of waxy and cuticle on the foliage, the stoma distribution had greater influence on PM-capturing capability.