Urban and peri-urban forests in the metropolitan area of Rome. Ecophysiological response of Quercus ilex L. in two green infrastructures in an ecosystem services perspective

Green infrastructures (GI), such as urban forests, deliver ecosystem services (ESs) and benefits. AmongESs the amelioration of urban air quality through the removal of air pollutants deserves large attentionowing to the positive impact on human well-being. Experimental data, as detailed descriptions of func-tional parameters, are needed for reliable quantification of ESs. The present study was carried out in themetropolitan area of Rome, considering an urban and a periurban forest. Both forests are dominated byQuercus ilex L., which has been chosen as target species for its wide natural distribution in the Mediter-ranean Basin, as well as for its widespread use in urban contexts. The two studied sites were characterizedby different environmental stressor and forest management practices, resulting in different trends of leafgas exchanges, photosystems functionality and plant water status. During spring, gas exchanges werelower in the urban than in the periurban forest, due to higher air temperature and vapor pressure deficitin the latter site. During summer, instead, in the periurban area the functionality of Q. ilex was affectedby drought, which did not occur in the urban forest due to higher summer rainfalls as well as periodicirrigations. The water use efficiency was basically lower in the urban park, as well as the photosystemsfunctionality. Differences in the intensity of the main phenological phases were also highlighted. Ourresults point out that the two GIs fulfill a complementary role in the ESs provision in the metropolitanarea of Rome, in relation to the ozone removal and the resulting air quality improvement and climateregulation.