First-time application of the IUCN urban Nature Indexes and its applicability for urban-related biodiversity conservation targets – A case study for Berlin, Germany

• First-time application of the Urban Nature Indexes (UNI) − for Berlin city in 2023. • UNI can support cities in assessing and achieving biodiversity targets. • UNI indicators cover all urban targets of biodiversity frameworks. • The application of UNI depends on the city’s data availability. • Scientific and political measures are needed for effective UNI implementation. Urbanisation is increasing rapidly worldwide and is one of the major pressures on the environment and its biodiversity. Therefore, biodiversity change in urban areas is considered an issue in several global, EU and regional biodiversity conservation frameworks. In order to meet urban-related targets, the status of urban biodiversity must first be assessed to provide a baseline for future evaluations. Cities are not only drivers of change and transformation, they are also the places where decisions will be made about how we will live on this planet in the future. In 2022, the International Union for Conservation of Nature (IUCN) developed the Urban Nature Indexes (UNI) to measure the ecological performance of cities and evaluate the effectiveness of conservation initiatives in urban ecosystems. The UNI consists of six themes and 30 indicators, covering a multidimensional approach to measuring urban ecological impacts. This study presents the first-time application of the UNI, realised in 2023 for the German capital Berlin, demonstrating the data sources used for 27 indicators and providing an example for other cities interested in applying the UNI. Furthermore, we demonstrate that all UNI indicators cover urban-related targets and areas of action of global, EU, and regional biodiversity frameworks. The UNI have the potential to support cities in achieving and evaluating targets implemented through policy for urban biodiversity conservation, which could play an important role in addressing the global biodiversity crisis.