Net particulate matter removal ability and efficiency of ten plant species in Beijing

Particulate matter (PM) removal is a major component of ecosystem services provided by urban green infrastructure. The annual PM removal service of plant species has generally been determined based on net PM removal ability. However, little is known about the leaf surface area normalized net PM mass removal abilities and efficiencies of different species. Net PM removal ability is the PM removed from the atmosphere by leaf surface during a period. We evaluated the net PM removal abilities and efficiencies of ten species based on quantitative leaf surface PM 1 day after and 21 days after a rainfall event. Net PM removal ability differed between plant species during the study period, and the net PM removal abilities were strongly correlated with the leaf surface PM 21 days after the rainfall, and this relationship weakened with the decrease of PM diameter. Plant species had significantly different net PM removal efficiencies except for large PM, and net PM removal efficiency was lower for coniferous trees and higher for species with high self-cleaning ability during our study period. Species differed in net PM removal ability and efficiency, and there were greater differences in the net removal ability of fine and coarse PM compared with large PM; therefore, care should be taken when species are selected for fine and coarse PM mitigation.

Automated summary

The study found that different plant species have varying abilities and efficiencies in removing particulate matter (PM), with species with high self-cleaning ability generally having higher net PM removal efficiency, while coniferous trees have lower net PM removal efficiency. Furthermore, there are greater differences in the net removal ability of fine and coarse PM compared with large PM, suggesting that careful consideration should be given when selecting species for fine and coarse PM mitigation.