Effect of multiscale plant traits on particulate matter resuspension

Resuspension of particulate matter (PM) from the surface of plants is a crucial process that affects their ability to mitigate atmospheric PM pollution. However, the influence of branch structural traits, leaf morphology, and leaf surface microstructures on PM resuspension is not sufficiently characterized. In this study, we conducted a wind tunnel experiment to investigate PM resuspension mechanisms for seven tree species with a variety of branch structures, leaf shapes, and leaf surface microstructural traits. The results show that 42.41 %-87.27 % of PM undergone resuspension among the seven tree species in speed tunnel experiment. The larger the particle size, the higher the proportion of resuspension. Wind speed is the primary environmental factor affecting the PM resuspension process. However, a hierarchical clustering analysis demonstrated that PM resuspension was more sensitive to exposure duration than to wind speed under low wind speed condition (1.5m/s-5m/s). For PM_2.5 and PM_2.5-10, the leaf surface roughness, groove width, stomatal density, stomatal size and complex branch structure were negatively correlated with the PM resuspension rate. Conversely, the leaf specific area, and leaf dry matter content were positively correlated with the PM_2.5 and PM_2.5-10 resuspension rate. By improving the characterization of PM resuspension mechanisms and influencing factors, this study provides new insights on the ability of plants to reduce atmospheric PM pollution.