Relationships between air particulate matter capture efficiency and leaf traits in twelve tree species from an Italian urban-industrial environment

Innovative Characterization of Particulate Matter Deposited on Urban Vegetation Leaves through the Application of a Chemical Fractionation Procedure

“…), three shrubs species ( Laurus nobilis L., Laurus cerasus L., Nerium oleander L.) and Hedera helix L., at high proximity from each other within the urban park “Le Grazie” (42°33′3.18″ N, 12°39′2.03″ E) on June, 15th 2017. A more detailed description of the sampling site and sampled species is reported in Sgrigna et al 2020 [ 18 ]. The leaves have been collected, both in Naples and Terni, more than 15 days after the last intense (i.e., precipitation rate higher than 10 mm h −1 ) rain event.…”

“…B ), comparable both to tree and shrub samples. In order to ensure homogeneity among the leaves sampled and avoid potential influence of their age (which could affect the time exposure to airborne PM pollution and the amount of particles deposited [ 50 ]), only the youngest ones were selected in both locations, thus sampling the leaves at the top of the branches [ 18 , 31 ].…”

“…In Naples, the cardinal direction was selected either toward the sea breeze from South-West (sites NA 1, NA 4, NA 5, NA 7), or toward the land wind from North-West (sites NA 2, NA 3, NA 6) [ 31 ]. In Terni, all the species were sampled from the East-North-East part of the crown, towards the wind direction coming from the steel plant (see Figure 1 b) [ 27 ], in order to select leaves under similar conditions, e.g., influenced by the same pollution source [ 18 ]. Leaves collected in both locations were preserved in paper bags to avoid external contamination and stored in freezer (−20 °C).…”

“…However, deposition of airborne particles on leaves is a complex and dynamic process, being influenced by numerous parameters. Leaf deposition efficiency depends on particles characteristics, such as their morphology and size [ 14 ], but also on species-specific leaf characteristics (such as leaf area, leaf morphology, density of stomata pores and thickness of wax layers) [ 15 , 16 , 17 , 18 ]. In addition, the density and the porosity of the tree crown, as well as meteorological conditions such as precipitations, wind speed and direction, result to be relevant in influencing the process [ 12 , 19 , 20 ].…”

Urban forests at the time of COVID-19 protect us from fine dust

“…È quindi opportuno, dove l'obiettivo sia di massimizzare il sequestro di particolato, andare ad identificare una miscela di specie di conifere e latifoglie ad elevata efficienza di rimozione di particolato, al contempo ecologicamente coerenti, in grado di adattarsi alle caratteristiche climatiche degli ambienti urbani. Sono in corso studi (Sgrigna et al 2020) per definire strumenti più efficaci di scelta delle specie di alberi più idonee in programmi di selvicoltura urbana sulla base della loro propensione specifica a rimuovere particolato di varie dimensioni, in diverse stagioni e in base a diverse morfologie fogliari e di architettura delle chiome.…”