Daniel Zhigila

and 4 more

Premise: Plants, particularly those with limited distribution ranges and small population sizes, are expected to be severely impacted by changing climatic conditions. Sesamum species are ideal for Species Distribution Modeling (SDM) in the context of climate change due to their narrow distribution ranges, agricultural and economic significance, sensitivity and adaptability to environmental conditions, wide geographic range, and potential to inform policy and adaptation strategies Methods: We used Maximum Entropy (MaxEnt) Model to quantify global ecological niche breadth of species in the genus Sesamum and to assess how bioclimatic and soil heterogeneity indices impact the future (to the year 2080) suitable distribution ranges of the genus Sesamum. We also quantified which environmental variables contribute most to driving the patterns and suitable geographical ranges for Sesamum. Results: Maxent models accurately predicted suitable habitats for Sesamum species. Precipitation patterns, especially seasonal extremes, were key determinants of species distribution. Temperature also influenced habitat suitability, with specific requirements varying among species. These findings highlight the complex interplay between climate and edaphic factors in shaping species distributions. Species with broader niches have larger geographic ranges. However, future climate change is predicted to reduce niche breadths for most species (74%), with some facing substantial range contractions. In contrast, a few species (11%) are projected to expand their ranges, while other species (15%) will experience negligible impacts. Phylogenetic analysis did not reveal significant patterns in extinction risk and niche breadth evolution. Conclusion: This study highlights the vulnerability of Sesamum species to climate change, with projected reductions in range sizes necessitating urgent conservation efforts. Prioritizing species such as S. forbesii and S. sesamoides, alongside targeted actions such as habitat restoration and long-term monitoring, is crucial to prevent population decline and potential extinction.