An innovative tool for supporting urban policies: assessing the health of mediterranean urban greenery with portable optical technologies and vegetation metrics

Urban green spaces are crucial for cityscapes, particularly in the context of escalating extreme weather, global warming, and pollution. Effective policy-making, planning and management of urban green infrastructure are critical for sustaining sustainable and healthier urban ecosystems. This study utilizes advanced optical technologies and standard vegetation metrics to assess the physiological status of Mediterranean plant species (Quercus Ilex L. and Nerium Oleander L.) across various urban habitats of Cagliari (Italy), compared to a control site in Sardinia's interior. Analysis of historical air quality data (2019-2023) identified two key periods—post-summer and post-winter—for evaluating plant responses to environmental factors and pollutants. Metrics such as leaf area, fresh and dry leaf weight, and trunk diameter were recorded. Additionally, portable sensors for Normalized Difference Vegetation Index (NDVI), fluorescence/transmission, and Raman spectroscopy were employed to non-invasively monitor leaf pigments. The results revealed species and location-specific variations in chlorophyll, polyphenols, and carotenoids, alongside different biometric trends. Future research will integrate soil analysis and satellite data to assess local factors like traffic density, land surface temperature, and pollutant distribution. This preliminary study aims to develop a comprehensive strategy for monitoring and managing urban greenery, ultimately fostering a greener and more sustainable city environment.