Porteurs du projet : Benoît GABRIELLE & Patricia GARNIER (ECOSYS)
Autres unités partenaires de BASC : ESE, LSCE, Economie Publique, SADAPT
Partenaires non académiques : Terre et Cité, EPAPS, AEV
Partenaires académiques hors BASC : GEOPS, INRAP, CEREMA-DTER IdF
Ecosystem services provide a unique, holistic framework to capture the interactions between global change (global warming, land-use changes, invasive species, environmental pollution) and ecosystems. For agricultural systems in particular, it can assess the multi-faceted impacts of agro-ecosystem management on the local environment, including changes in biodiversity through the alteration of trophic networks and prey-predator dynamics. However, there is currently no methodological consensus on how ecosystem services should be evaluated and thence a pressing need for quantitative approaches based on measurable parameters of ecosystem functioning.
The ASSETS project aims to quantify ecosystem services through quantitative methods from plot to territory scales through quantitative methods (field monitoring, modeling, indicators), and to examine how they are influenced by biophysical drivers, ecosystem management and land planning. The project includes a range of services relevant to the global change drivers considered, encompassing provisioning services (for food and fresh water), regulation and maintenance (of climate, flood and nutrient supply), and cultural services (recreational and archaeological archive). As a core component of agro-ecosystems, biodiversity changes and their impacts on biomass provision services will be examined.
The project focuses on the transitions in land-use and agricultural management practices in a case-study area known as the 'Saclay plateau', a 80-km2 peri-urban area currently undergoing urbanization in the context of the development of the top research, innovation and business cluster of France. A particular attention will be paid to a section on the southern fringe of the plateau where arable fields are likely to undergo land-use changes within a few years. An experimental approach will be developed on a commercial field undergoing changes in fertilizer management via the use of urban waste composts from a nearby waste processing facility. The water discharge rate from the field drains and the concentrations in nutrients and pesticides will be monitored. A wider set of plots will be monitored for biophysical and ecological variables and derive a bundle of services provided by different agro-ecosystem types, and their evolution after undergoing a change in use or management will be assessed.
The perception of ecosystem services and biodiversity-related issues by local stakeholders is also likely to affect the management of some species, and drive changes in agro-ecosystem management or land-use, in response to new expectations from the latter. ASSETS will investigate the representations and expectations of local players including land managers with respect to ecosystem services and propose tools to elicit them and take them into account when developing projects in a peri-urban context. The indicators developed during the project on ecosystem services and biodiversity will be used as criteria for developers and stakeholders for the evaluation of changes in land use and management, whether ex ante or ex post. Land-use change scenarios involving the conversion to agro-forestry or tree orchards may be explored via simulation modeling and based on the data collected on the arable plots of the plateau's fringe.