Аңдатпа
Sibiraea altaiensis (L.) Schneid. is a characteristic species of high-mountain ecosystems in Eastern Kazakhstan, Sibiraea altaiensis experiences intense solar radiation, sharp temperature fluctuations, low humidity, and nutrient-poor soils. This study presents a comprehensive ecological–anatomical analysis of the leaves and stems of S. altaiensis from natural populations of the Katon-Karagay National Park. Anatomical parameters were examined using classical microtechnical methods, morphometry, and statistical approaches. The leaf of S. altaiensis demonstrates a pronounced combination of xeromorphic and oromorphic traits. The leaf blade has a stable thickness, a well-developed cuticle, and a hypostomatic epidermis. A thickened palisade layer and a moderately variable spongy layer, reflecting adaptation to high insolation and limited moisture, characterize the dorsiventral mesophyll. The vascular bundles are reinforced with sclerenchyma, providing mechanical stability under strong winds. The stem is characterized by well-developed xylem, stable dimensions of vascular elements, and a thick periderm, which performs protective and mechanical functions. Correlation analysis revealed coherence among the main anatomical parameters, including leaf thickness, mesophyll structure, vascular bundle size, and xylem development. The weakly acidic, low-mineral soils of the habitats correspond to the moderate plasticity in mesophyll and conducting tissues. Thus, S. altaiensis exhibits a complex of anatomical and morphological adaptations enabling survival under extreme high-mountain conditions of the Kazakh Altai. These findings contribute to a better understanding of the adaptive evolution of Rosaceae taxa in Central Asia and are relevant for further taxonomic and conservation research.