Regulating ecosystem services and green infrastructure. Assessment of urban heat island effect mitigation in the municipality of Rome, Italy

The Urban Heat Island (UHI) effect is one of the main environmental impacts of urbanization, affecting directly human health and well-being of the city dwellers, and also contributing to worsen environmental quality. As a key strategy to address sustainable urban development, the EU has advocated the development of Nature-Based solutions, such as the implementation of Green Infrastructure (GI), which can deliver a wide range of Regulating Ecosystem Services (ES). In this article, the ES of climate regulation provided by GI has been analyzed in the Municipality of Rome, Italy, characterized by a complex territory and by a Mediterranean climate. The methodological approach allowed to characterize the UHI and to analyze its features in a spatially explicit way and on a seasonal basis, through the Land Surface Temperature (LST) derived from Landsat-8 data. The cooling capacity of different GI elements (peri-urban forest, urban forest, street trees), as well as the effect of vegetation cover and tree diversity on the provision of this regulating ES were assessed. The results show that GI significantly mitigates the hot urban climate during summer, with an effect that is dependent on the GI element and the environmental constrains to which it is exposed. NDVI and tree cover resulted the main indicators of the provision of the ES of climate regulation, highlighting that GI elements such as urban and peri-urban forests have the highest potential to provide this ES in a Mediterranean city. In the context of the Mapping and Assessment of Ecosystems and their Services (MAES) process, our results lend support to claims that GI is important for an ecosystem-based climate adaptation strategy in urban environments, contributing to the definition of knowledge based criteria and indicators, relevant for decision-making in Mediterranean cities.