Dust captured by a canopy and individual leaves of trees in the tropical mixed deciduous forest: Magnitude and Influencing factors

Forest tree leaves play a significant role in air purification, but forest fires could offset the dust sink role. This study aims to assess the functions of the forest in atmospheric dust sink and source and assess the dust capturing capacity of individual leaves of various tree species in the tropical mixed deciduous forest in the dry season (24 November 2021 to 23 January 2022), along with its influencing factors—climatic variables, environmental variables, and leaf morphology. The result shows that the downward flux or the forest dust sink role was predominant at the midday when air-mass turbulence played a role. Nonetheless, net mass PM 1 and PM 10 concentration trapped by the forest canopy was low, 0.79 and 2.24 µg m − 3 , respectively. Forest fires as PM 2.5 sources to the atmosphere could outrun the PM 2.5 sink role for entire of the dry season. Considering the individual tree leave, maximum dust capturing capacities for the forest trees ranged from 0.95 g m − 2 to 5.197 g m − 2 . Leaf dust capturing capacity was enhanced under cold and dry weather and for trees with defoliated or irregular-shape. Leaf/leaflet enhancing the dust capturing capacity exhibited large size; either thick and leathery texture (Coriaceous) or thin, semi-translucent, membrane-like texture (Membranaceous); indumentum top being either short, stiff trichomes (Scabrous) or without trichomes (Glabrous); or indumentum bottom surface being densely short, soft trichomes (Tomentose). The various dust capturing dynamics among tree species could benefit dust capturing by the forests in the dry season.