Home – Home – Jornals – Geography and Natural Resources 2022 number 2

This paper presents the results of studies aimed at identifying statistical relationships between the landscape structure and the variability in Siberian stone pine (Pinus sibirica) increments in the permafrost-hillocky northern-taiga landscapes of Western Siberia (Nadym river basin). Dendrochronologies of Siberian stone pine growing on frost mounds of different types were compiled. Principal component analysis was applied to obtain independent variables that describe the site and landscape structure of the territory. Cores from 512 trees growing on 23 frost mounds were analyzed. The methods used were as follows: crossdating, dendrochronological standardization, and elimination of monotonic trends for each tree. Results of the classification of Sentinel satellite images were used to calculate the proportions of lakes, forests, sparse forests, floating bogs and flat-hillocky peat bogs, with the radius of the vicinity of a frost mound of 100-2000 m. Correlation, dispersion and regression analyses were used in the analysis of the dependence of the median increment on the characteristic of the mound site and landscape neighborhoods. It is established that on high mounds the variability in increments is higher on tops than on slopes, whereas the situation is often the contrary on low mounds. It is also found that the tops and slopes of the frost mounds respond differently to climatic fluctuations depending on the landscape structure and the height of the mound: the close proximity of lakes reduces the variability of phytoproductive functioning on the summit surfaces. It was revealed that the sensitivity of Siberian stone pine growth to temperature fluctuations increases with an increase in the diversity of the facies structure caused by the development of thermokarst subsidence and cryogenic cracks.