民勤植物园3种灌木的叶面微结构及其滞尘能力研究

粉尘已成为中国北方空气中的主要污染物之一,植物可吸附和截留大气中的粉尘,对其滞尘能力的研究可为绿化树种选择与配置提供参考。本研究观测蒙古扁桃(Amygdalus mongolica)、山桃(A. davidiana)和中华钙果(Cerasus humilis)的叶形状,用面积仪测定面积、周长、长、宽,用电子显微镜观测叶面附属物及微结构;采用“收集-清洗-过滤-称重”的方法收集叶面滞留的粉尘;比较分析叶的形状、大小及其微结构与其滞尘量的关系。结果表明：蒙古扁桃滞留小于10 μm的颗粒物能力相对较强,中华钙果滞留粒径大于10 μm(PM10)能力相对较大。叶的单位面积滞尘量是蒙古扁桃>中华钙果>山桃。叶面微结构影响叶面滞留粉尘的能力,粉尘主要滞留在叶毛周围,镶嵌在叶面沟状结构和气孔之间。单位叶面积滞尘量与叶面积、叶周长、叶宽、叶长成负相关关系,与叶宽/叶长之比值成正相关系,其中叶面积和叶长对滞尘量影响较大。

Study on the Leaf Microstructure and Dust Retention Ability of 3 Plants in Minqin Botanical Garden

The dust has become one of the main air pollutants in north China. Plants can absorb and retain the dust in the atmosphere, and the study on dust retention capacity of plant could provide references for the selection and configuration of greening tree species. In this study, the leaf shape of Amygdalus Mongolia, A. davidiana and Cerasus humilis were observed, the leaf area, perimeter, length and width were measured by platometer, and leaf appendages and microstructure were observed by electron microscope. The dust detained on the leaf surface was collected by the method of “collection-cleaning-filtration-weighing” and the relationship among the leaf shape, size, microstructure and dust retention amount were compared and analyzed. The results showed that the capacity of Amygdalus Mongolia to retain the particles less than 10μm was relatively strong, and the capacity of Cerasus humilis to retain the particles larger than 10 μm (PM10) was relatively big. The dust retention per unit area of leaf was Amygdalus Mongolia > Cerasus humilis > A. davidiana. The microstructure of leaf affected the capacity of dust retention on the leaf, and the dust was mainly around the hair of leaf, or inlayed in the groove and stomata on the leaf. The dust retention amount of per unit leaf area was negatively correlated with leaf area, perimeter, width and length, and positively correlated with the ratio of leaf width to leaf length, among which leaf area and leaf length had a greater impact on the dust retention amount.