ИСТИНА

The aim of the study was to define possibilities and restrictions for the tree-ring reconstruction of climatic parameters and streamflow. We examine sensitivity of nine pine chronologies (Pinus Sylvestris) to the main hydrometeorological factors that determine tree growth patterns, and analyze the climatic response of these chronologies. The climatic data for Volga region (53-56N, 46-52E) is limited by length of instrumental hydroclimatic observations. The length of meteorological datasets for precipitation and temperatures is shorter then 120 years, and for the streamflow, is even shorter and goes up to a maximum of 70 years only. Tree ring growth in Volga region is mainly controlled by temperatures and precipitation during the vegetation period. Most tree-ring chronologies have stable and significant negative correlation with summer temperatures and positive response to precipitation in current year period from July to September as well as previous year period from July to August. All pine chronologies have stable and significant response to Palmer Drought Severity Index (PDSI) during the year. The strongest signal was found for the dry season in the current year period from July to September. As for relations between streamflow and tree growth, the strong dependence was identified between the tree's response to streamflow and the distance to hydrology stations. Our reconstruction of Ilet river streamflow from 1827 to 2013 was based on this relation. We also reconstructed PDSI from 1828 to 2013, using the master-chronology based on PCA analysis. The models explain 27 to 34 % of the PDSI and streamflow variability. The reconstructed datasets reflect the main extremes in the actual data.