Abstract: In order to compare the relationship between the dust retention on leaf surface in the unit area and the stomatal characteristics of three evergreen plants, the relationship between the dust retention per unit area and stomatal density, stomatal opening degree and guard cell area were analyzed with Euonymus japonicus, Buxus sinica and Yucca gloriosa by centrifugal weighing method, freehand and microscopic observation. The results showed: the dust retention of Euonymus japonicus was higher than Buxus sinica and Yucca gloriosa, and the amount of dust in unit area (7.376 3 g/m²) was also significantly higher than that of other two species. The stomatal density of three evergreen plants was significantly different, and Euonymus japonicus was higher than Buxus sinica while Buxus sinica was higher than Yucca gloriosa. The stomatal density of Euonymus japonicus was higher than Yucca gloriosa and Populus simonii, which indicated that the high dust retention of Euonymus japonicus was related to its stomatal density, and its air ports were easy to hold dust. The stomatal opening of Euonymus japonicus was the largest among the three plants, and that of Buxus sinica was the second while Euonymus japonicus was the least, which showed that the stomatal opening was not related to the dust retention. The guard cell area of Euonymus japonicus was higher than Buxus sinica and Yucca gloriosa, and the relationship between the area of the guard cell and the dust retention remains to be verified by other species. It was probable that the smaller guard cells were, the less water was lost, the wetter foliage can be and more dust was adsorbed. It was suggested that Euonymus japonicus should be selected with priority for urban greening in Tianjin.

Key words: Tianjin, evergreen plants, dust retention, stomatal characteristics