Response of plant species to impact of climate change in Hugumbrda Grat-Kahsu forest, Tigray, Ethiopia: Implications for domestication and climate change mitigation

This study aimed to predict distribution and Total Carbon Stock (TCS) dynamics of Acacia abyssinica, Carissa edulis, and Juniperus procera in the Hugumbrda Grat-Kahsu National Forest in current (1970-2000) and future climate scenarios (2021-2100). Bioclimatic, soil, and elevation data were used for modeling using Maxent, with model accuracy evaluated using Area Under the Curve (AUC), Kappa test and True Skill Statistic (TSS). Significant differences were observed in distribution of species between current and future periods under Shared Socioeconomic Pathways (SSPs) of SSP2-4.5 and SSP5-8.5 scenarios. The main contributing predictors of the species distribution were temperature seasonality, altitude, and precipitation of the warmest quarter. All species were projected to shift to higher altitudes in the future. Acacia abyssinica's current potential distribution (42.9 %) could expand to 77.1-99.2 % (SSP2-4.5) and 63.8-72.9 % (SSP5-8.5). Carissa edulis could extend from 54.2 % to 89.5-100 % (SSP2-4.5) and 77.1-87.9 % (SSP5-8.5). Juniperus procera's might increase from 63.8 % to 91.8-99.7 % (SSP2-4.5) and 78-88.1 % (SSP5-8.5). The projected future climate is expected to result in an expansion of new suitable areas for all three species. The TCS estimates per km2 were 169 (Acacia abyssinica), 46 (Carissa edulis), and 1381 ton (Juniperus procera). In SSP2-4.5, Acacia abyssinica's TCS could rise from 25,688 to 59,319 tons, Carissa edulis from 8,832 to 16,284 tons, and Juniperus procera from 312,106 to 487,493 tons. In SSP5-8.5, projections indicated 43,602 tons (Acacia abyssinica), 14,306 tons (Carissa edulis), and 430,872 tons (Juniperus procera). The study concludes by recommending the strategic planting of these species in both current and future suitable areas to enhance ecosystem services and ensure their sustained existence in the face of changing climates.