CLIMATIC SYGNAL IN TREE-RING WIDTH OF CONIFERS AT THE NORTH AND CENTER OF THE EAST-EUROPEAN PLAIN
The analyses of climatic response of all available 52 tree-ring width chronologies of spruce, pine and larch in the European Russia allowed the identification of the most important climatic parameters influencing the radial growth of conifer trees in two large regions, homogenous in terms of climate, namely in the northern and central parts of the European Russia. Despite the strong local signals and not high coefficients of correlation between the ring width and climatic parameters it is obvious that all conifers growing to the north of 60N react positively to summer temperature (minimum, maximum, mean temperatures of the warm season and individual months). To the south, at the latitude of 54-56 N the signal is changing and the ring width depends on the combination of two parameters – warmth and humidity (precipitation, drought index PDSI, relative humidity of vegetation season). The negative correlation of the spruce ring width with the temperature of the end of previous vegetation season is confirmed for the whole territory of northern and central European Russia.
Fig. 1. Study region. Circles - pine tree-ring chronologies, triangles– spruce chronologies, squares – larch chronologies. Filled marks - chronologies made in Tree-ring Lab, IGRAS, emoty marks –chronologies from ITRDB.
Fig. 2. Spaitial correlations of pine tree-ring field with а) – minimum air temperatures in May-August, б) – precipitation in July. Bold line is the border of significant correlations (p=0,05). Period AD 1901-1990. Black dots are tree-ring sites.
Fig. 3. Spaitial correlations of spruce tree-ring field with а) – mean air temperatures in June-July, б) – PDSI severity index in June-July. Bold line is the border of significant correlations (p=0,05). Period AD 1901-1990. Black dots are tree-ring sites.
Fig. 4. Spaitial correlations of larch tree-ring field with а) – minimum air temperatures in June, б) – air humidity previous August. Bold line is the border of significant correlations (p=0,05). Period AD 1901-1990. Black dots are tree-ring sites.