Dendrochronological Verification of Forest Site Regionalization in the Dark Coniferous Forests of Southwestern Altai

Abstract

Abstract

Background and Aim. The forest-growth regions of the dark coniferous forests of the Rudny Altai were identified by E.M. Seversky in 1971 based on geobotanical, soil, and orographic criteria. Over the past 50 years, climatic conditions in the region have tended to change, which may lead to shifts in forestgrowth regions relative to previously established boundaries. The objective of this study is to assess the dynamics of radial growth of Abies sibirica Ledeb. within forest growing regions and to verify their spatial homogeneity along the altitudinal profile using dendrochronological analysis.
Materials and methods. The study was conducted at four sample plots located within forest-growth regions II, III, and V at elevations of 550 and 940 m above sea level. Wood samples were collected, cross-dated, and standardized tree-ring series were obtained, and synchronization statistics (Rbar and EPS) were calculated. Correlation analysis between growth indices and climatic data for the period
1970-2025 was performed.
Results. Differences in radial growth along the altitudinal gradient were identified. The middlemountain plot (940 m, region II) was characterized by the highest EPS values (0.91) and a negative correlation with mean annual temperature (p < 0.05). The low-mountain plots (region V) show higher
synchronization and lower sensitivity to climatic factors. These differences indicate the heterogeneity of forest stands within the boundaries of the forest-growth regions.