West African rangelands are invaded by Senna obtusifolia, a non-palatable and non-nodulating annual legume. Its invasion has negative ecological and economic impacts in Sahelian countries. Despite its growing impact and its expansion into the Sudanian zone, the reasons for its recent invasion as well as consequences for local ecosystems and livelihoods are poorly understood. This project aims to identify environmental drivers that promote the expansion of S. obtusifolia, to determine effects of S. obtusifolia invasion on ecosystem functions and services, to examine
perceptions of local land-users on S. obtusifolia expansion and their respective adaptation strategies, and to propose potential solutions and best-practices to control the invasion of S. obtusifolia and its negative impacts on rangelands. We will collect ecological data along a steep climatic gradient, contrasting sites with various levels of invasion. A greenhouse experiment will be implemented to elucidate the local adaptation rates of S. obtusifolia. To assess effects of S. obtusifolia invasion on forage provision, we will apply field spectroscopy. Interviews will be used to explore the ecological knowledge of rural populations, related to local management
strategies applied to control S. obtusifolia. This project will render an improved scientific knowledge on causes and effects of S. obtusifolia invasion. Moreover, a national risk map of S. obtusifolia invasion, technical reports and a manual of best practices to control land invasion by S. obtusifolia will be provided to stakeholders.
This project is structured in four research activities with duration of 3 years and the budget requested from Volkswagenstiftung is 199,700 EUR.

- 3 publications scientifiques : (1). Ouédraogo K., Zaré A., Korbéogo G., Ouédraogo O. & A. Linstädter (2021) : Resilience strategies of West African pastoralists in response to
scarce forage resources, Pastoralism: Research, Policy and Practice,11:16
https://doi.org/10.1186/s13570-021-00210-8; (2) Zaré A., Traore I.C.E., Hien B.S., Bonde L. & O. Ouedraogo (2022); Local Knowledge, Perceptions and Uses Values of Senna obtusifolia (L.) H.S. Irwin & Barneby, an Invasive Native Plant Species in Burkina Faso, West Africa. Scientific Journal, ESJ, 18 (30), 343. https://doi.org/10.19044/esj.2022.v18n30p343; (3). Zaré A., Bougma P.C., Ouedraogo K. & O. Ouédraogo (2022): Assessing the competitive ability of the invader Senna obtusifolia with coexisting natives’ species under different water stress regimes. Journal of Experimental Biology and Agricultural Sciences. Volume – 10(5)-page 1149
– 1167. http://dx.doi.org/10.18006/2022.10(5).1149.1167
- Formations de compétences : 2 Thèses, 2 Masters et 1 Licence Professionnelle

Volswagen foundation