Dust pollution: Its removal and effect on foliage physiology of urban trees

Urban trees are now considered as an eco-sustainable tool used to monitor and mitigate air pollution. An experimental study was carried out to investigate the dust removal efficacy of urban roadside trees of tropical region and impact of dust load on foliage physiology and micromorphology. Result of the study suggested Ficus virens as highest dust depositing tree followed by Ficus religiosa > Cassia fistula > Azadirachta indica. However, foliage traits dependent dust deposition was maximum in Azadirachta indica, followed by Ficus virens and Ficus religiosa and least dust deposition was found in Cassia fistula. Whereas, deposited dust caused negative impact on leaf area, biomass, pigments, and membrane permeability of selected trees species while, ascorbic acid content and stomatal index was increases in all selected roadside trees. Tolerance of plant against air pollution was identified with the help of air pollution tolerance index using pH, ascorbic acid, relative water content, and total chlorophyll. Experimental tree Ficus virens showed higher air pollution tolerance index followed by Ficus religiosa > Azadirachta indica, and > Cassia fistula. Study concluded Ficus virens as a multi benefiting tree for sustainable urban plantation planning owing to its high air pollution tolerance index and moderate dust capturing capacity.