Effect of the longitudinal temperature gradient on the Main Radial Growth of Forest Trees North-West Siberia

Abstract

Influence of temperature longitudinal gradient on radial growth and light ring formation of spruce (Picea obovata Ledeb.) and larch (Larix sibirica Ledeb.) in the north subzone of taiga forest in Western Siberia was studied. The influence was estimated by three parameters: statistical characteristics of treering chronologies along the longitudinal gradient; relationship between tree-ring chronologies and air temperature; abnormal tree-ring structures (light rings). Spruce tree-ring chronologies show increasing response to air temperature along the longitudinal gradient from west to east. For larch tree-ring chronologies, increasing statistical values was found along the longitudinal gradient from west to east, but obvious changes of radial growth response in this direction were not found. Frequency and intensity of light ring formation do not depend on the longitudinal gradient in area under study. However, temperature difference between light ring years and non-light ring years decreases along the longitudinal gradient.We believe that the formation of light rings depends on local geographic and climatic conditions.