2015/01/01 by P.G. Mestayer, Gilles Mestayer, Patrice, Yves Brunet +1
Environmental Science · #Air Quality Monitoring and Forecasting
paper · doi:10.15454/1.4622651014844446e12
Urban vegetation directly impacts the atmospheric composition and the budget of pollutants according to five principal modes: a physicochemical mode of absorption and adsorption of principally gaseous pollutants, an aerodynamic mode by which vegetation retains particulate pollutants and modifies pollutant dispersion by turbulent wind flows, especially in the case of porous barriers, a chemical mode of volatile organic compounds emission, a biological mode of allergenic pollen emission, and finally a photochemical mode through the CO2-consuming photosynthesis. The positive or negative balances strongly depend on the pollutant species, the geographical situation, the seasons, the urban morphology, and vegetation infrastructures. Some infrastructures also have indirect impacts on air quality via, e.g., shadowing and parasites. On average, the impacts are weak or negligible, and the influence of urban vegetation on the air quality of cities remains marginal.