Sensing Urban Green Spaces Through Portable Photonics-Based Devices: Initial Findings in the Metropolitan Area of Cagliari

Green spaces in urban areas are pivotal in shaping city landscapes, gaining increased importance amid escalating impacts of extreme weather events, global warming, and urban pollution. Innovative strategies for urban green infrastructure planning and management are essential to nurture a healthier city ecosystem. This research focuses on employing portable photonic devices to scrutinize the physiological conditions of specific Mediterranean plant species (Quercus Ilex L., Nerium Oleander L., and Prunus Cerasifera Ehrh) in different urban habitats (central and peripheral) of the city of Cagliari. During the post-summer period of 2023, an extensive measurement campaign was performed. Leaf Area, Leaf Fresh and the Normalized Difference Vegetation Index (NDVI) of the plant canopy were assessed. Portable fluorescence/transmission- and Raman-based sensors were used to non-invasively monitor leaf pigment-related indices that showed variations as a function of species and urban zones. Different plant species responses were observed across both zones, marked by an imbalance in chlorophyll indexes and distinct variations in polyphenol and carotenoid indexes. Notably, Quercus Ilex L. and Nerium Oleander L. exhibited higher variability compared to Prunus Cerasifera Ehrh.. This preliminary study lays the groundwork for the development of a protocol to identify resilient plant species tailored to specific urban environments, contributing to the enhancement of urban greenery.