Invasive species are known to be a threat to agriculture and biodiversity. Thus, many studies have focused on the negative ecological impacts of invasive species, while their importance to livelihoods and human well-being has received little attention. This study aimed to explore people's ethno-ecological knowledge about the invasion of Senna obtusifolia and the importance of this species in some local ethnic groups according to two climate zones in Burkina Faso. Three hundred (300) people from eight (08) ethnic groups from surrounding villages of pastoral zones in two contrast climate zones were interviewed. The survey technique was semi-structured interviews, using a previously tested semi-structured questionnaire. A Generalized Linear Model (GLM) with the Poisson distribution was performed to determine the factors that influence the ethno-ecological knowledge of people. For informants, the most important dissemination drivers are animals in the Sahelian zone and humans in the Sudanian zone. Regarding usefulness, the species is harvested by people for 08 use categories with food (100%) and construction (46%) as the most use categories. In fact, use value of Senna obtusifolia differed significantly among climatic zones, ethnic groups (P < 0.001). Furthermore, a significant difference between the Mossi and Fulani of the Sahelian zone and those of the Sudanian zone was observed. This study revealed the usefulness of Senna obtusifolia for people and findings are essential to promote the species utilization, which could be considered as adaptation strategy to the negative ecological invasion of the species. Moreover, these findings could guide the formulation of management policies and how to valorise more the invasive species.

Background: Faidherbia albida parkland provide many ecosystem goods and services to people, ranging from provisioning to regulating services. Despite this importance, these parks are degraded due to overexploitation, which is accentuated by the adverse effects of climate change. In this context of climate change, little information exists on the state of these F. albida parkland, particularly their diversity and structure along the North-South climatic gradient. This study aims to determine the effect of climatic gradient of F. albida parklands in order to provide updated data for sustainable management. Floristic diversity and population structure were assessed through forest inventories in the three climatic zones of Burkina Faso. Thus, 99 circular plots of 1 ha were sampled in three zones, including 33 per climatic zone. The data processing concerned the calculation of diversity indices (Shannon, Piélou equitability, and species richness), importance value indices, and the calculation of the means of the dendrometric parameters. The analyses were based on the comparison of medians using the Kruskal-wallis test, and the effect of the climatic gradient on the different variables was tested using generalized linear models. All of these analyses were carried out using the R.4.0.5 software. Results: The dendrometric parameters and floristic diversity vary significantly (Pv˂0.05) according of climatic zone. Furthermore, based on ecological importance value indices and diameter class structure, the majority of dominant species (11) show a regressive dynamic in all three climatic zones characterized by abundance of old individuals at expense of young ones. This reflects an ageing and continuous destruction of these parklands. However, species such as V. tortilis (Sahelian zone) and A. indica (Sudano-Sahelian and Sudanian zones) show good dynamics. As for F. albida, its structure is regressive in all climatic zones.Conclusion: Although the climatic gradient has a significant effect on the diversity and species structure of F. albida parkland, their current dynamics are thought to be due to unsustainable management of local populations.