Guidelines for sustainable conservation of Kigelia africana based on ecological niche modelling under climate change in Benin, West Africa

Kigelia africana is a forest species threatened by anthropogenic and climatic actions. Conservation possibilities of Kigelia africana were investigated using MaxEnt and ENMTools algorithms, R software and GIS in two modeling approaches considering the whole population and population subgroups. This is to determine the ecological niches of Kigelia africana and to test the hypothesis of conservatism of the ecological niche along the Beninese climatic gradient of Kigelia africana. Climate projections were made for 2041-2060 under the SSP 5-8.5 (Shared Socioeconomic Pathways) climate scenario with Global Climate Models (GCM). The results revealed three distinct homogeneous subgroups in the K. africana population characterized by mean annual temperature, the average diurnal temperature difference, the minimum temperature of the coldest month, the average temperature of the coldest quarter, the total annual precipitation and the precipitation of the coldest quarter. The predictions were different from those of the whole population with an AUC value indicating that subgroups provided the best model. Low similarity as well as niche divergence were observed for these subgroups. Additionally, the Northern and Southern subgroups will expand into other niches while the Central subgroup will lose much of its niche in the future. There was therefore no niche conservatism between the different subgroups of K. africana. The results validated the hypothesis that individuals of this species may respond differently under the influence of climate change and provided solid guidelines for sustainable management of K. africana.