Manon Edo

• Agricultural intensification, while initially boosting productivity, has led to significant environmental degradation. The widespread use of synthetic inputs and mechanization have contributed to the simplification of landscapes,leading to habitat loss, biodiversity decline, and the disruption of ecological processes. Consequently, the sustainability of farming systems has been compromised, endangering the provision of crucial ecosystem services essential for both the long-term agricultural viability and the human well-being. Agroforestry—through the deliberate integration of trees into agricultural landscapes—emerges as a promising strategy to reconcile food production with the conservation of biodiversity and the maintenance of crucial ecosystem services. This thesis investigates the potential of silvoarable and silvopastoral systems to support the diversity of birds, bats, and spiders across a range of European agricultural contexts. Chapters II, III, and IV reveal distinct benefits of agroforestry systems for each group. While birds benefited from the structural heterogeneity provided by woody elements in agroforestry systems, bat activity and diversity were primarily influenced by prey and shelter availability—especially in fields with older deciduous trees and grazing livestock. Both bird and bat diversity responded positively to within-field variables. In contrast to birds and bats, spider diversity did not significantly respond to within-field features. However, spider community composition differed across habitat types, with agroforestry systems—due to their structural heterogeneity—supporting species with a range of habitat preferences. Overall, the findings from Chapters II, III, and IV indicate that agroforestry enhances bird and bat diversity compared to open agricultural fields. Moreover, by increasing within-field structural complexity, agroforestry systems also create habitat conditions favorable to both open- and woodland-associated bird, bat and spider species. These studies highlight the potential benefits of agroforestry systems for supporting bird, bat, and spider communities. A broader implementation of such systems could play a crucial role in halting and reversing the dramatic biodiversity decline observed across European farmlands. The findings also emphasize the importance of considering multiple taxa and ecological traits in conservation strategies, as species respond differently to habitat structure and environmental variables. Moreover, the thesis underscores the value of maintaining a heterogeneous landscape mosaic composed of cultivated and permanent semi-natural and woody elements to maximize biodiversity. Despite its ecological potential, the adoption of agroforestry in Europe remains limited, hindered by policy gaps, mechanization trends, and socio-economic barriers. Effective implementation will require coordinated efforts across policy, research, and practice, recognizing that biodiversity-friendly farming must occur at both field and landscape scales. These studies contribute empirical evidence that agroforestry can serve as a keystone practice in the transition toward resilient, multifunctional agricultural landscapes that integrate biodiversity conservation with productive land use.