Modelling the current and future distribution of Caesalpinia bonduc (L.) Roxb: Its implication for future conservation of the species in the Southern Benin

Caesalpinia bonduc (L.) Roxb, the most commercialised medicinal species in Southern Benin, is reported to be extinct in the wild due to anthropogenic pressures on its natural habitats. Remaining individuals can only be found in traditional agroforestry systems and home gardens. It is therefore important to understand how spatio-temporal distribution of the species could be impacted by changing environmental conditions and propose strategies to be used for its conservation. Maximum Entropy (MaxEnt) modelling technique was used for modelling the current and future distribution of the species using present-day combined with two future forecast scenarios (Representative Concentration Pathways-RCP): low-RCP4.5 and high-RCP8.5 emission scenarios. Environmental and demographic factors have impacted the distribution of the species. Rainfall driest quarter (44.5%), population density (30.4%), rainfall driest month (14.7%), potential evapotranspiration (6.5%) and number of dry months (4%) mostly contributed to the model. High suitable areas of the species will increase about (2.28%) and (0.06%) with the RCP8.5 and RCP4.5, respectively, at horizon 2055. In contrast, less suitable areas will decrease about 3.11% (RCP4.5) and 1.71% (RCP8.5). In-situ conservation strategy is suggested to restore the species in the wild taking into account suitable areas for its growth, development and reproduction. Circa-situ conservation should be promoted in agroforestry systems and home gardens for sustainable use of the species.