Comparative Analysis of Dust Retention Effects on the Surface of Leaves of Eight Common Street Trees

Abstract

In order to select excellent green tree species, street trees commonly found in the Yizhou urban area 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 particles 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/m 2 ), while C. japonicum was the smallest (average value was 0.1245 g/m 2 ). 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 retention effect of eight species of street trees in Yizhou, it can be seen that Ficus con-cinna has the strongest dust retention ability, and can be used as the preferred tree for street trees in local busy traffic areas.