Dust-retention Capability and Leaf Traits of Common Park Greening Plant Species in Zhengzhou City

It is of great significance to study dust-retention of urban garden plant species and to select those with strong dust retention ability to improve urban environment.Ten common park greening plant species occurring in Zhengzhou city were selected to quantify particles with different sizes(TSP,PM＞10,PM10,PM2.5) per unit leaf area using a membrane filtration method.The influences of the leaf traits on dust-retention ability were analyzed.The results showed that there were significant differences in the dust retention per unit leaf area and the dust retention of different particle sizes among the 10 plant species（P＜0.05）.Generally, the arbor tree species had stronger dust-retention ability than shrub species.Cedrus deodara and Sabina chinensis had a strong ability to retain TSP and PM＞10 on their leaves.C.deodara,Photinia serrulata and Nerium indicum had strong ability to retain PM10 and PM2.5.Nandina domestica had the weakest ability to retain TSP,PM＞10,PM10 and PM2.5.The dust-retention ability was influenced by leaf surface morphology.The leaves of C.deodara,S.chinensis,P.serrulta and N.indicum with rough surface, sticky grease or obvious veins had strong dust-retention ability.There was correlation between the amount of dust-retention and the contents of wax from leaves.There was significant and positive correlation between the amount of PM10 and PM2.5 and the contents of wax, while there was no significant correlation between the amount of TSP and PM＞10 and the contents of wax.Wax contents had a notable influence on the dust retention ability of fine particulate matter.The ability to retain PM10 and PM2.5 increased with wax contents.Therefore, the dust-retention ability was influenced by leaf surface morphology and wax contents.C.deodara,S.chinensis and P.serrulta that had strong dust-retention ability could be considered as urban landscaping plant species in Zhengzhou city.