RL3. Biophysical interactions in multifunctional landscapes: How the diversity of land cover, organization and management of a territory can be manipulated to promote resilience and sustainability?

In the face of the need to reduce the reliance on external inputs while mitigating climate and air pollution and maintaining production in agricultural systems, we argue that the territory (or landscape) is a key scale at which to intervene. At this organization level, cropping systems may be organized and diversified to provide multifunctional landscapes that increase resilience to plant disease, thus reducing pesticide usage, abate nitrogen supply and losses of reactive N to air and water, provide bioenergy and fiber products without reducing food production, save promote by producing agricultural goods closer to their consumption point and ultimately lower the local and global impacts of that territory on the environment and human health.

These benefits occur as a result from interactions at the landscape scale, between agro-ecosystems and also other landscape components such as urban land-uses - which are especially relevant in contexts involving urban to rural gradients. Interactions at agro-ecosystem level involve for example crop disease and the emissions of GHG and pollutants, or atmospheric pollution and crop production. While dual interactions may be relatively well-known, such as the effect of fertilizer N inputs on GHG emissions, or the effect of pesticide application on crop production, multiple interactions are less straightforward to grap (eg, climate * nitrogen * pesticides * GHG emissions).

This research priority will hence aim at unravelling the effects of territorial interactions on ecosystem functioning and services (biomass production and carbon storage), GHG and pollution emissions as well as the dynamics of plant pathogens. We will try to evaluate the effects of a diversity of cropping systems and management at the landscape scale on these outputs, and provide insights into resilient multifunctional landscapes. Our specificity will be to treat pathogens, GHG and pollutant dynamics, and the exposure of crops to atmospheric pollutants all together. This research line will contribute to the structural themes « Diversity from field to landscape for a resilient agroecosystem with limited impact » and « Exposure to and effects of contaminants in agroecosystems».

Examples of research we would aim to promote include (1) the interactions between nitrogen supply and pathogen dynamics and its effects on GHG and pollutant emissions at the landscape scale. We will approach this issue first by coupling our models with emulation methods complement them with observations when relevant; (2) the effects of urban and sub-urban vegetation on local and regional microclimate and air? pollution and its possible impact on crop productions. This work will benefit from developing work in the GALOP project and the projects being constructed.