Dendroclimatology of Scots pine (Pinus sylvestris L.) in the Usmansky pine forest conditions of Voronezh region

Abstract

The dynamics of the radial increment of a 150-year-old Scots pine (Pinus sylvestris L.) tree stand in the Usmansky pine forest, Voronezh region (island forest of the forest-steppe of the Russian Plain), was studied as an indicator of the dynamics of climatic conditions and the basis of tree stand productivity. The cyclical dynamics of the increment of total, early and late wood of Scots pine over a period of more than a century was revealed, due to the influence of growth-limiting climate factors. In the dynamics of fluctuations in the total width of tree rings and early wood of Scots pine, as well as the growth-limiting factor, atmospheric precipitation, the Brickner cycle prevails, lasting 32, 40-41 years. The 11- and 24-year cycles are also clearly visible. In the dynamics of latewood fluctuations, the 10-11-year cyclicity is most pronounced. In solar activity fluctuations, the leading one is the 10-11-year cyclic component. Fluctuations in the hydrothermal coefficient are dominated by a high-frequency component (2-4 years); low-frequency cyclicity is also present (73, 50, 38 years, etc.). Correlations and the strength of influence of key limiting factors for the Central forest-steppe have been established: the amount of precipitation and air temperatures. The importance of March precipitation for the formation of early wood and April precipitation of late wood was revealed. For May-August, there is a clearly expressed positive correlation with precipitation (up to 0.42 in May for early wood) and a negative correlation with temperature (up to -0.3 for early wood, also in May). The correlation coefficient with the HTC is significantly higher than with precipitation and temperature separately for all types of wood. The relationship is positive and significant (0.52-0.55). The strength of influence on the formation of the width of annual rings is also maximum for HTC (up to 81 % for late wood). A preliminary assessment of carbon sequestration by mature pine plantations was carried out. It was revealed that one average tree of a 150-year-old forest stand deposited 12.8 g of carbon on average over the last 10 years (2013-2022).