Climate change may favor the expansion of Adenium obesum in arid and semi-arid regions?

Future climate change may affect in the environmental suitability, which refers to the set of conditions necessary for a species to establish itself in a given ecosystem. The species Adenium obesum has a native distribution in desert regions, suggesting its adaptation to hot and arid climates. Thus, this study aimed to model the species environmental suitability for hot and dry climates, considering the premise of global temperature increase and the consequent possibility of expanding its distribution area. Occurrence data for Adenium obesum were obtained from the Global Biodiversity Information Facility (GBIF), while climate variables were sourced from the WorldClim database (version 2.1), with a spatial resolution of 5 arc-minutes. The modeling process employed the following algorithms: BRT, GAM, GLMPoly, MARS, MaxEnt, RF, and RPart. The models were evaluated using statistical metrics, considering those with AUC > 0.9 as potentially useful. For the True Skill Statistic (TSS) method, values above 0.7 were classified as good. To quantify, in km², the difference between the species' current potential distribution and the environmentally suitable areas projected for the future, the results were binarized, allowing the calculation of expansion, contraction, stability, and absence percentages. The future projections indicate an expansion of Adenium obesum, confirming the hypothesis that, due to its ecological and environmental characteristics, the species may achieve greater success in colonizing new areas under future climatic conditions characterized by higher temperatures and lower precipitation.