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.