Résumé
We are constructing a project that will integrate ecology and the ecological knowledge of herders to understand the relationships between livestock and vegetation dynamics in the arid savannas of the northern Sahel. As ecologists, we start with two opposing hypotheses, each of which has its defenders: (i) Grazing and browsing drive vegetation dynamics, and overgrazing leads to rangeland degradation; (ii) in contrast to humid savannas, plant production and livestock numbers in arid savannas are in most years so limited by rainfall that in wet years with greater plant production, livestock never approach carrying capacity and thus have little effect on vegetation dynamics. Herders’ perspectives on these questions are largely unexplored. As ethno-ecologists we will collaborate with herders to gain their grounded understanding of the interactions between grazing by their animals and plant responses to grazing. This will helpclarify the issue and suggest new questions for both ethnoecological and ecological research. This double approach requires close collaboration with herders. To accomplish this, we are building the project based on the recruitment of motivated young herders as « para-ecologists ». In addition to their direct involvement in research, they will facilitate communication with other more experienced herders to fully plumb local ecological knowledge and build a holistic knowledge base that will better inform rangeland management for a diversity of ecosystem services. We also base our approach on direct field observations in order to integrate ongoing changes in herders’ practices. Considerations from ecology suggest that changing patterns ofgrazing distribution in time and space—increasing concentration of livestock around watering points, intense grazing pressure earlier in the season, before annual grasses and forbs can flower and seed--can increase livestock’s negative impact. However, preliminary observations of herder practices suggest that they counter these patterns and minimize their impact. We suggest therefore that both ecology and ethnoecology are required to build sound projects that fully consider social-ecological dynamics. Our goals will be to explore the local knowledge of herders that drives how they manage grazing in space and time. Our strategy will be to fully engage herders as partners in research.