Metal Accumulation Capability by Platanus acerifolia (Aiton) Willd., Ailantus altissima (Mill.) Swingle, Robinia pseudoacacia L. and Quercus ilex L., Largely Distributed in the City of Rome

The main of the research was to analyze the leaf metal accumulation capability of Platanus acerifolia (Aiton) Willd., Ailantus altissima (Mill.) Swingle, Robinia pseudoacacia L. and Quercus ilex L., largely distributed in Rome. In addition, metal concentration was analyzed in the soil, sampling sites were chosen in historical parks (A sites) and high traffic level sites (B sites). The results highlight significant higher leaf and soil metal concentrations in B than in A sites. The ratio between metal concentration in leaves and soils (Biological Absorption Coefficient, BAC) for all the considered sites was significantly different among the species. Morphological and anatomical leaf traits of the considered species show significant differences in A and B sites in response to traffic level. Overall, the results highlight the importance of the selection of tree species in urban areas for their ability to lower pollution levels.