The Influence of the Urban Environment on Biodiversity: From a Systematic Literature Review to Spatial Planning Integration in Italy

Urban biodiversity conservation has become a priority in policy and academic discussions worldwide. In the specific European political context, several initiatives and regulations for biodiversity conservation have recently been proposed and implemented, including the recent Biodiversity Strategy for 2030. In this framework, Italy faces the urgent challenge of adapting national and local urban policies to ongoing, ever-increasing urbanization. This study addresses the knowledge gap between recognized urban threats to biodiversity and their practical mitigation through spatial planning tools. Thus, the present study aims to (i) identify the main threats to biodiversity in urban environments through a systematic literature review focused on the Italian context, and (ii) propose strategies and interventions for integrating these findings into urban planning, particularly within the framework of the municipal urban plan that regulates land use at a local level under Lombardy Regional Law No. 12 of 2005. The four main threat categories identified through the systematic literature review affect different taxonomic groups, including birds, pollinators, invertebrates, plants and soil biota, and the related urban planning responses include: improving management of existing green spaces in compact cities, prioritizing quality instead of merely quantity of green spaces; the promotion of native vegetation in e.g., afforestation actions; the support for ecological connectivity; and, a reduction of soil sealing. The results of this study will inform practical urban planning decisions and will be particularly useful for policymakers and practitioners aiming to achieve good ecological status and address biodiversity loss.