TREE PLANTING STRATEGIES AS NATURE-BASED SOLUTION FOR THE PROVISION OF ECOSYSTEM SERVICES

Abstract Climate change, biodiversity loss, ecosystem degradation, and rapid urbanization are intensifying environmental pressures worldwide, with growing impacts on ecological integrity and human well-being. In this context, Nature-based Solutions (NBS), and particularly tree-based interventions such as urban afforestation and agroforestry, are increasingly promoted as effective strategies to enhance biodiversity, mitigate climate change, and improve regulating ecosystem services. However, the outcomes of tree planting practices are highly context-dependent and may involve trade-offs, highlighting the need for evidence-based approaches to guide planning and management across different landscapes and scales. This thesis investigates the ecological and social benefits of tree-based interventions through three complementary studies. • CHAPTER 1: Urban afforestation and meadow management as key drivers for wild pollinator conservation This study aims to advance the understanding of the role of urban afforestation in biodiversity conservation, using wild bees as bioindicators. By adopting a chronosequence approach in forests of different ages and integrating information on forest structure and adjacent grassland management, this study addresses the gap in understanding how forest maturation and management practices jointly influence pollinator communities in highly anthropogenic environments. The results provide insights into functional biodiversity responses to urban afforestation and highlight management strategies capable of enhancing habitat quality and ecological connectivity at the local scale. • CHAPTER 2: Assessing the future of coffee agroforestry: carbon dynamics and climate resilience through forest modelling - A Preliminary Study This study represents the initial application of the FORMIND forest model for agroforestry systems, specifically simulating coffee crops to assess how shade trees affect carbon balance and crop resilience under future climate scenarios. Its aim is to contribute to addressing the lack of long-term, mechanistic assessments of agroforestry performance, and to clarifying trade-offs and synergies between shade trees and crop productivity, as well as the limits of agroforestry as a climate adaptation and mitigation strategy under increasing climatic stress. However, some relevant processes still need to be implemented in the model to fully capture the complexity of agroforestry systems. • CHAPTER 3: Afforestation priority for multiple objectives at national scale: Italy as a case study This study proposes a workflow to identify priority areas for afforestation at the national scale, considering four distinct objectives related to different ecosystem services: ecological connectivity, human health, climate mitigation, and water regulation. This approach makes it possible to highlight areas where benefits are maximized, thereby providing a strategic national perspective to support political decision-making in land management and planning. Using Italy as a case study, environmental and social spatial indicators were integrated into a goal-specific multi-criteria analysis, generating priority maps at a 1 km resolution.