MODELING THE DISTRIBUTION OF Aloe ankoberensis AND Aloe debrana UNDER DIFFERENT CLIMATE CHANGE SCENARIOS IN NORTH SHEWA ZONE, AMHARA NATIONAL REGIONAL STATE, ETHIOPIA

Abstract

Aloe ankoberensis M.G. Gilbert & Sebsebe and A. debrana Christian are endemic species of Ethiopia that are currently listed as endangered and least concern, respectively under international union for conservation of nature (IUCN) category. Recent studies concluded that climate change is predicted to be one of the primary drivers which determine the distribution of plant species. Therefore, this study aimed to model the distribution of A. ankoberensis and A. debrana under different climate change scenarios in the North Shewa Zone, Amhara National Regional State of Ethiopia. In this study, 36 and 397 georeferenced presence points were used for A. ankoberensis and A. debrana, respectively. In addition, 12 environmental variables were used for both species. The ensemble model approach was used to examine the current and future (2050 and 2070) climatic suitability for both species under three shared socio-economic pathway (SSP) climate scenarios (SSP 2.6, 4.5 and 8.5). The performance of the ensemble model was excellent for A. ankoberensis with mean area under curve (AUC) 0.96 and true skill statistics (TSS) 0.88, and good for A. debrana with mean AUC of 0.87 and TSS of 0.63. The findings showed that the main variables that affected the species' distributions were mean diurnal range, annual precipitation, and elevation. According to the model, under the current climate conditions, 98.32%, 1.01%, 0.52%, and 0.15% were not suitable, low, moderate, and high suitable areas, respectively for A. ankoberensis, and 63.89%, 23.35%, 12.54%, and 0.21% were not suitable, low, moderate and high suitable areas, respectively for A. debrana. Under future climate scenarios, these species' suitable areas could shrink. Moreover, low suitable area for A. ankoberensis will be 4.45%, 2.35%, and 1.84% under SSP (2.6, 4.5, and 8.5) scenarios, respectively in 2050s. Under similar scenarios and years, the moderate suitable area for A. debrana, will be decreased by 100%, 94.63%, and 84.95%, respectively, while, decreased by 97.52%, 99.97%, and 100%, respectively in 2070s. In addition, under all climate change scenarios, it is anticipated that highly suitable areas for both species and moderately suitable areas for A. ankoberensis will completely be lost in the future unless crucial interventions are done in time. Area suitability increases as annual precipitation increase from 1000mm to 1200mm for A. ankoberensis, and from 800mm to 1100mm for A. debrana. Therefore, creating a plan for species conservation and strengthening climate change adaptation strategies are essential for preventing the loss of suitable habitats for these endemic Aloe species.