Abstract: Based on analyses of leaf surface dust retention and retained dust particle size of 20 commonly used greening tree species in natural environment, and comparison with atmospheric dust, we analyzed the difference in dust retention capacity and particle size of different species, and examined the effects of leaf morphology and leaf surface microstructure on the mechanical composition of retained dust. There were significant differences in dust retention capacities of the 20 species. Euonymus japonicus showed the highest dust retention capacity of 1.75 g·m^-2, while Viburnum opulus subsp. calvescens showed the lowest value of 0.40 g·m^-2, being 4.4 times less than that of E. japonicus. The distribution curves of particle size of retained dust on leaf surfaces of 20 species were classified into three categories: two-peak distribution, three-peak distribution, and four-peak distribution. The particle size of atmospheric dust in the same period showed a three-peak distribution. The difference in particle size between atmospheric dust and retained dust by the 20 tree species indicates that leaves had a selective retention effect on atmospheric dust. The leaves of different tree species had different retention capacities for particles of differentsizes, and the volumetric content of PM>10 from foliage dust was the largest. The blades with grooves were more conducive to the retention of PM_2.5, while the leaves with protruding structures were more conducive to the retention of PM>10. Blades with rough microstructures, such as fluff, grooves, and protrusions, had strong dust retention capacity. Our results can guide the selection of suitable greening tree species for different pollution sources, alleviating air pollution, and improving air quality.

Key words: particle size, leaf surface microstructure, atmospheric dust, dust retention on leaf surface, leaf morphology.