GI Guidelines for the Metropolitan City of Cagliari (Italy): A Method for Implementing Green Areas

The decline of natural capital resulting from urbanization has triggered phenomena such as landscape fragmentation and loss of biodiversity. European institutions have published documents and strategies with the purpose of counteracting such phenomena. In this regard, in 2020 the European Commission released the European Biodiversity Strategy 2030, which defines biodiversity conservation objectives and promotes the implementation of green infrastructures (GIs) designed to supply ecosystem services, which can increase people’s well-being. The scientific literature has scarcely dealt with methods for drafting guidance documents (guidelines) to support public administrations in the implementation of GIs. In this study, we aim at designing and applying a method for drafting GI guidelines. We apply the method to the Metropolitan City of Cagliari, the main urbanized area—which partially includes the former Province of Cagliari—of Sardinia (Italy). According to the findings, a proposal of GI guidelines should be rooted in context analysis and consistency checks and should be tailored to specific geographical and institutional contexts. The preliminary guidelines described in this study are designed to provide public administrations with GI guidelines based on scientific, technical, and cultural considerations, and are aimed at supporting an effective implementation of GIs and a GI network.