Finding sufficient natural fodder resources to feed livestock has become a challenge for herders in the Sahel zone of Burkina Faso. Despite the existence of pastoral reserves, the issue of fodder shortage remains unsolved. This article highlights the changes in behaviour and the evolution of pastoral practices caused by the scarcity of forage resources. These changes are defined and classified as resilience strategies. Thus, this paper aims to analyse these strategies using new semantics that calls for other forms of perceptions or approach to the questions of pastoralists’ resilience strategies. Interviews (semi-structured and casual conversations), ethnographic observations and ethnobotanical surveys were used to collect data. In rangelands, such high value fodder species as Andropogon gayanus, Pennisetum pedicellatum and Dactyloctenium aegyptium that were abundant herbaceous plants during the last decades are disappearing. Concomitantly, species with lower forage value, such as Senna obtusifolia, which are more resilient to ecological disturbance factors, are colonizing rangelands. Faced with these ecological changes, pastoralists are trying to redefine and reconfigure their practices, and this implies a redefinition of their identity. They use resilience strategies such as mowing grasses, building up fodder bundles, conserving crop residues, exploiting Senna obtusifolia (a previously neglected species), using woody fodder and adapting the type of livestock and the size of the herds to the ability of pastoralists to feed them. Strategies that are older than these are the integration of agriculture with livestock and decollectivized transhumance. It is these resilience strategies that this article exposes and analyses as defence mechanisms of Sahelian pastoralists in the face of the depletion of forage resources in their environments.

Invasive species tend to pose a threat to ecosystem biodiversity, functioning, and ecosystem service provision. This study was conducted in Burkina Faso to assess the competitiveness of an invasive species Senna obtusifolia that is a less palatable legume plant in West African Sahelian rangelands. To address the research hypothesis that the recurrent drought in the Sahel results in S. obtusifolia being more competitive in the land invasion, we conducted an interspecific competition involving S. obtusifolia and 3 herbaceous species (Andropogon gayanus, Chamaecrista mimosoides, and Pennisetum pedicellatum) in a greenhouse experiment under four water stress regimes using a replacement series design. The height and biomass of each species were measured throughout four months experiment. In the severe water regime, S. obtusifolia was the most sensitive to water deficit while the 3 other species were found to be resistant. In addition, in all water regimes, the aggressivity index revealed that S. obtusifolia was less competitive than the grass species A. gayanus and P. pedicellatum. Further, the study discovered that drought in the Sahel made S. obtusifolia more vulnerable than the other species. Hence the invasion of Sahelian rangelands by S. obtusifolia could be favored by overgrazing that reduces fodder species' dominance and competitiveness. Good management of sahelian rangelands by controlling grazing could help to reduce S. obtusifolia invasion and provide more fodder for livestock.