A scenario-based approach to tackle trade-offs between biodiversity conservation and land use pressure in Central Italy

Land Use and Land Cover Changes (LULCC) are recognized among the main drivers affecting biodiversity and ecosystem services. Especially in areas with high biophysical and socioeconomic heterogeneity, the need to find optimal planning solutions to combine human and natural systems still remains an open issue. This study aims to investigate how different planning strategies affecting the spatial arrangement of LULCC can produce different impacts in terms of ecosystem conditions in the Lazio region, Central Italy. Starting from the same LULCC magnitude observed in the past through an inventory approach, three different future scenarios to 2030 were depicted by means of the InVEST tool Scenario Generator: the "Business as Usual" (BaU) and, alternatively, one avoiding changes within the "Natura 2000" sites (N2K) and another within the regional most "Degraded Municipalities" (DM). The ecological impacts of these scenarios were then assessed using the InVEST Habitat Quality model, adopting Habitat Quality (HQ) as a proxy for biodiversity. In order to characterize LULCC impacts at multiple scales, the assessment was carried out both at the regional level and within distinct ecological units. Independently from the spatial arrangement of projected LULCC, HQ decreased under all three scenarios. Nonetheless, HQ values varied among scenarios, highlighting a strict relationship between the spatial arrangement and the ecological impact of LULCC. Compared to BaU, alternative scenarios, as well as their combination into a "Best Scenario", reduced negative impacts on HQ. These results highlighted the weak sustainability of pursuing with past urban planning strategies, while allowed to foster innovative planning approaches to mitigate habitats loss and degradation. The proposed methodology was effective to localize the conservation priorities as well as ameliorating the reliability of planning strategies based on their ecological performance. Furthermore, it supports the resolution of planning conflicts between contrasting demands (e.g., urban expansion vs biodiversity conservation), thus enhancing simultaneous benefits for both nature and people.