STRANGE

Streams are traditionally viewed as receptacles rather than sources of energy with regard to nutrient and energy cycles. However, numerous studies have shown that lakes and rivers are important source of energy for the terrestrial environment, mainly through the emergence of winged aquatic insects, by providing nutritional subsidies to terrestrial consumers. The objective of this project is to evaluate the ecosystem services provided by aquatic ecosystems in adjacent agricultural environments. More precisely, (1) we will focus on three ecosystem services provided and mediated by emerging aquatic insects that are fundamental to agronomy (pollination, foodweb support, and soil fertilization). (2) In parallel to the first objective, we will study the history of the governance of French riparian areas to examine current management practices, their associated representations, and their recent improvements in the governance in order to increase the adoption of ecologically responsible practices by stakeholders. (3) We will map physical and biological characteristics of streams and catchments with high-resolution data and remote sensing techniques to estimate the respective contribution of various drivers (land uses, landscape features, etc.) and spatially exhaustively evaluate the related ecosystems services at multiple scales. To achieve these objectives, we will rely on five sites located along a gradient of agricultural intensification and in different agricultural context. This selection follows a call for collaboration within three Zones Ateliers (ZA Armorique, ZA Loire, ZA Brest-Iroise) from the French Long Term Socio-Ecological Research network (LTSER RZA). The two PIs will be helped is their tasks by 15 other scientists from 11 research units with complementary skills in ecology (plant and animal ecology, foodweb, pollination), geography (remote sensing, spatial modeling, land use planning) and social scientists (ecological economy, management, planning).