Self-adaptation of tropical agro-socio-ecosystems to global changes? A long term study for ecological intensification of cereal production in West African savannas. – CERAO

The objective of the CERAO project is to improve cereal production in semi-arid sub-Saharan regions in West Africa, while identifying ecological and social meta-rules that confer viability and sustainability to agro-socio-ecosytems despite higher climatic and demographic constraints. The main hypothesis is that viable and sustainable agro-socio-ecosystem trajectories are guided by meta-rules derived from natural ecosystems functioning. Consequently, concepts developed in ecology and complexity sciences will be reused to analyze agro-socio-ecosystems trajectories during a five last decades as well as their viability and sustainability. Such an approach will allow us to determine the key meta-rules to provide guidance in future agricultural intensification schemes.
The specific objective will be to analyze and produce models of trajectories for contrasted agro-socio-ecosystems in a context of strong climatic or socio-economic constraints. The project will rely on a diachronic and multidisciplinary analysis in the Peanut Bassin of Senegal. Over the last decades this area faced significant climate change, which started with severe droughts in the 70s, and experienced socio-economic disruption marked by significant population growth and strong rural exodus. The study site is included in the long term observatory of health and population of Niakhar where three contrasted neighboring agro-socio-ecosystems. The trajectories during the last decades of these three situations are will be studied in term of social structure, cropping systems, livestock systems and soil fertility management..
Project activities are organized around 3 mains tasks. Task 1 will precise the local dynamic of climate (task 1.1), population (task 1.2), and land use (task 1.3) over the past decades. The task 2 aims at describing the trajectories of households (task 2.1), cropping systems and crop performance (task 2.2), organic matter and nutrients cycles (task 2.3), and cultivated cereal biodiversity (task 2.4). Task 3 will synthesize all collected data and knowledge produced by developing and validating different modeling tools: a household-model integrating a dynamic crop module (task 3.1), a community and village level multi-agent system (task 3.2) and a multi-scale compartment model coupled to a nutrient network analysis (task 3.3). The task 3.4 uses these models to simulate past trajectories of studied agro-systems and to identify meta-rules guiding these trajectories on the basis of a multi-disciplinary approach. Models will be designed and validated with all the project multi-disciplinary partners and the stakeholders involved in the functioning of studied agro-socio-ecosystems in the studied area.
The French partners are UMR ECO&SOLS “Ecologie fonctionnelle et biogéochimie des sols et des agrosystèmes” ; UMR DIADE “Diversité Adaptation Développement des plantes » ; UMR LPED “Laboratoire Populations Environnement Développement”; UMR SELMET «Systèmes d’élevages méditerranéens et tropicaux » ; and two senegalese partners : LNRPV « Laboratoire national de recherche sur les productions végétales » of ISRA « Institut Sénégalais de recherche agricole », and LPAOSF (Laboratoire de physique de l’atmosphère et de l’Océan » of UCAD (Université Cheikh Anta Diop) in Dakar.
Main project outcomes will be (i) an up-to-date database describing environmental, agronomic, demographic and social evolution, (ii) models of organic and nutrient fluxes at different time and spatial scales, (iii) scenarios of adaptation to environmental and demographic changes (iv) prospective options for better staple food production in the studied areas (iv) the building-up of a multi-disciplinary research consortium, (v) high-level publications in peer-reviewed journals and general public communications on social and ecological concepts related to ecological intensification of agro-socio-systems in Sub Saharan Africa.