Naturalized Acacia saligna has been widely introduced across dryland regions as a fast-growing species for landscape rehabilitation and soil stabilization. However, the ecological determinants governing its establishment, distribution, and growth performance remain insufficiently characterized. This study examined how key environmental variables and their interactions shape the distribution, abundance, and morphological traits of A. saligna populations, in Tigray, Ethiopia. Field surveys were conducted in 52 plots across five sites spanning an altitudinal range of 1960-2400 m and slope gradients of 5.2-41 %. Regression and correlation analyses were applied to identify environmental predictors of population density and growth performance. The occurrence of A. saligna was significantly influenced by tude at one site (P < 0.05), while abundance exhibited negative associations with soil pH, slope, sodium, magnesium, organic carbon, and bulk density. When data were pooled across sites, predominantly positive relationships emerged, except for slope, sand and clay content, available phosphorus, calcium, and magnesium. Population density was marily regulated by soil sodium, pH, cation exchange capacity (CEC), bulk density, and exchangeable potassium. phological traits, diameter at breast height (DBH), total height (Ht), crown diameter (CD), crown depth (CDp), crown area, showed strong positive intercorrelations (P < 0.05). Sand content positively influenced morphological velopment, likely through enhanced drainage and reduced compaction. Multiple regression and principal component analyses revealed that DBH was significantly affected by Ht, CDp, CEC, calcium availability, altitude, and slope, height exhibiting strong co-variation with DBH, CD, and CDp. These results demonstrate that A. saligna performance highly sensitive to site-specific edaphic and topographic conditions. Integrating such environmental diagnostics restoration planning is therefore essential to optimize species establishment, prevent maladaptation, and improve logical outcomes in dryland restoration programs.