Abstract
This study evaluates the physicochemical properties of soils supporting natural populations of Ajania fastigiata (C.Winkl.) Poljakov in the Ile Alatau region of Kazakhstan. Soil analyses revealed clear differences among populations in moisture regime, nutrient availability, carbonate accumulation, exchangeable bases, and soluble salts. In all profiles, soils were weakly alkaline, with pH ranging from 7.71 to 8.12, and were predominantly characterized by a light loamy texture. The highest surface soil moisture was recorded in Population 3 (14.53%), whereas the lowest value in the deeper horizon was observed in Population 1 (6.13%). Population 3 was distinguished by elevated humus content (7.54%), available phosphorus (86 mg/kg), available potassium (490 mg/kg), and carbonate content (6.86%), indicating more favorable edaphic conditions. In contrast, Population 2 showed the highest surface nitrogen content (100.8 mg/kg) and relatively higher bicarbonate and total soluble salt contents (0.046-0.074%). Population 1 was characterized by the lowest salinity level, with total soluble salts decreasing from 0.049% to 0.018% along the soil profile. In all soils, Ca²⁺ dominated the exchange complex, while Na⁺ remained low. These findings demonstrate that local edaphic differences play a key role in shaping the ecological conditions of Ajania fastigiate populations in the Ile Alatau.