SPECIES DISTRIBUTION MODELING OF Terminalia brownii FRES UNDER CURRENT AND FUTURE CLIMATE SCENARIOS: IMPLICATIONS FOR DRYLAND RESTORATION IN ETHIOPIA

ABSTRACT This study examines the potential distribution of Terminalia brownii, a drought-tolerant tree species, to identify suitable areas for dryland restoration. Using MaxEnt species distribution modeling, current and future habitat suitability under three climate scenarios (Shared Socioeconomic Pathways (SSP)1-2.6, SSP2-4.5, and SSP5-8.5) for the periods 2040–2060 and 2080–2100 was assessed. Key environmental variables, including Bio12 (Annual Precipitation), Bio16 (Precipitation of Wettest Quarter), and elevation, were incorporated into the model to predict the species' distribution. The outputs were reclassified into three suitability categories: low, moderate, and high, based on a logistic threshold of 0.2235. The results indicate that Terminalia brownii currently occupies 34.05 million hectares of suitable habitat, with 1.1 million hectares identified as highly suitable. By 2050, under SSP1-2.6 and SSP5-8.5 scenarios, the moderate and highly suitable areas are projected to expand significantly, with potential growth in arid and semi-arid regions. Conversely, the SSP2-4.5 scenario predicts a more limited expansion. By 2090, highly suitable habitats are expected to increase under all scenarios, particularly under the high-emission SSP5-8.5, where suitable areas could reach up to 32 million hectares. The findings highlight the resilience of Terminalia brownii to climate change, making it a valuable species for restoring degraded landscapes. This study provides critical insights into the spatial distribution of Terminalia brownii under changing climate conditions and offers guidance for prioritizing areas for restoration to enhance ecosystem resilience in Ethiopia’s drylands.