八种常见行道树叶表面滞尘效果的比较分析
Comparative Analysis of Dust Retention Effects on the Surface of Leaves of Eight Common Street Trees

为了筛选优良的绿化树种，以宜州城区常见的行道树为研究对象，利用激光粒度分析仪、扫描电子显微镜及相关处理软件，对八种行道树叶表面滞留的大气颗粒物粒径、叶表面微观结构及其与单位叶面积滞尘量的相关性进行比较分析。结果表明：1) 本研究的行道树种叶表面滞留的大气颗粒物粒径大部分介于0.2 μm~ 6.0 μm之间，其中，秋枫叶表面滞留的大气颗粒物粒径主要为1 μm左右，其余7种行道树叶表面滞留的大气颗粒物粒径主要为0.2 μm~1 μm和3 μm~5 μm；2) 不同行道树种叶表面的单位面积滞尘量有较大差异，其中，小叶榕最大(平均值为0.6895 g/m²)，天竺桂最小(平均值为0.1245 g/m²)，不同行道树种叶表面的单位面积颗粒物滞留量排序为：小叶榕 > 红花羊蹄甲 > 高山榕 > 杧果 > 秋枫 > 桂花 > 白兰 > 天竺桂；3) 叶表面微观结构与其滞尘量相关性较大，其中，保卫细胞面积、气孔宽度与单位叶面积滞尘量呈极显著的正相关，气孔密度和气孔长度与单位叶面积滞尘量呈显著负相关或正相关。从宜州八种行道树叶片滞尘效果的综合比较分析中可知，小叶榕的滞尘能力最强，可作为当地交通繁忙区行道树的优选树种。
In order to select excellent green tree species, street trees commonly found in the Yizhou urban ar-ea were selected as the research objects. The particle size, leaf surface microstructure and their correlation with dust retention per unit leaf area were compared and analyzed by laser particle size analyzer, scanning electron microscope and related processing software. The results showed that: 1) the particle size of retained atmospheric particles on the leaf surface of the street tree species in this study was mostly between 0.2 μm and 6.0 μm. The particle size of retained atmospheric parti-cles on the leaf surface of the B. javanica leaf was mainly about 1 μm, and the particle sizes of the other 7 street tree leaves were mainly 0.2 μm~1 μm and 3 μm~5 μm. 2) The dust retention per unit area of the leaf surface of different street tree species was significantly different, among which, F. concinna was the largest (average value was 0.6895 g/m²), while C. japonicum was the smallest (av-erage value was 0.1245 g/m²). The order of particle retention per unit area of the leaf surface of different street tree species was as follows: F. concinna > B. blakeana > F. altissima > M. indica > B. javanica > O. fragrans > M. alba > C. japonicum; 3) the microscopic structure of the leaf surface was significantly correlated with the dust retention amount, among which, the area of stomata guard cells and stomatal width were positively correlated with the dust retention amount per unit leaf area, and the density and length of stomata were negatively or positively correlated with the dust retention amount per unit leaf area. From the comprehensive comparative analysis of the dust re-tention effect of eight species of street trees in Yizhou, it can be seen that Ficus concinna has the strongest dust retention ability, and can be used as the preferred tree for street trees in local busy traffic areas.