DENDROCLIMATIC STUDIES OF SCOTCH PINE IN THE SOUTHERN TAIGA ON THE EASTERN EDGE OF THE RUSSIAN PLAIN

Abstract

Regional dendroclimatological studies demonstrate the most accurate results when climatic responses of woody plantsto changes in climatic factors are identified in one particular region. Coniferous trees are the most frequent object of observation in suchstudies as they are more longevous and sensitive to changes in external factors. The paper presents the results of dendroclimatic investigation of growth variability of Scotch pine (Pinus sylvestris) growing in the southern taiga on the eastern edge of the Russian Plain. Chronology construction and data analysis were performed using CooRecorder, CDendro, COFECHA, ARSTAN and R programs. The obtainedtree-ring chronology of Scotch pine covers the time interval from 1822 to 2022, with a series duration of 201 years. The maximum growthwas observed in 1950 (1.21 mm), 1984 (1.25 mm), 2010 (1.37 mm). The minimum increment was in 1914 (0.75 mm), 1942 (0.77 mm),1977 (0.78 mm), and from 2015 to 2017. The analysis of correlation dependence of Scotch pine growth and climatic conditions showedthat the growth and development of the studied trees have been most influenced by changes in air temperature in June of the of the previousyear and current years, the correlation coefficient (R) is 0.068 and 0.156, respectively, as well as in October of the previous and currentyears - 0.352 and 0.221, respectively. The amount of precipitation has a smaller impact on growth. Thus, the factor of growth and development of Scotch pine on the eastern edge of the Russian Plain in the southern taiga subzone is mainly the air temperature in the fall monthsof the previous year and current year as well as the June temperature of the current year.