Effects of agroecological practices expansion on biodiversity and ecosystem service multifunctionality in agricultural landscapes

Abstract: Many studies conducted in controlled conditions or natural ecosystems demonstrated that biodiversity enhances multiple functions and ecosystem services. However, evidence from highly anthropized ecosystems, such as agricultural fields, remains scarce. Moreover, most of existing studies have focused on biodiversity – multifunctionality relationships at the local scale, often overlooking how these relationships emerge at larger spatial scales. At the landscape scale, habitat complementarity can enhance biodiversity and ecosystem functioning, and several ecosystem services depend on spatial dynamics. Yet our understanding of these spatial processes in intensively managed agricultural landscapes is still limited. This PhD thesis aims to identify how the large-scale deployment of agroecological practices affects biodiversity, ecosystem services, and multifunctionality (i. e., the capacity of an ecosystem to provide multiple ecosystem services simultaneously) quantified at the landscape scale. To do so, we will collect data on biodiversity and ecosystem services across different habitats along a landscape gradient of increased share of agroecological farming, in two study-regions dominated by vineyards or cereal fields in the South-West of France. Different provisioning, regulating, supporting and cultural services will be considered, with the objective of quantifying ecosystem services supply and multifunctionality at the landscape scale. By explicitly working in managed landscapes, this design will allow us to quantify how landscape-scale multifunctionality responds to the deployment of agroecological farming. This work will produce theoretical knowledge on the role of biodiversity spatial dynamics in sustaining multifunctionality, as well as operational insights for the spatial management of agricultural landscapes facing multiple and sometimes competing demands.