ИСТИНА

Much of the southern part of European Russia is lacking in high-resolution paleoclimate data. Thus, we present the first vegetation period (March-September) mean temperature reconstruction in the Caucasus Mountains derived from tree-ring data. The material was collected from upper-tree limit (2200-2400 m a.s.l.) in the Teberda river valley. Optical density measurements of resin-extracted Pinus sylvestris (L.) samples were obtained by using flat-bed scanner and commercially available software. Final maximum density (MXD) chronology covers period of 1759-2005s. and contains 43 tree-ring series. Only period of chronology that starts from 1800s. is reliable and can be used for further reconstruction. It was defined according to Expressed Population Signal that exceeds values more than 0,85. The nearest meteorological station Severny Kluhor is located at the altitude of 2042 v a.s.l. and reflects climatic conditions close to the tree-line. The MXD chronology indices show positive correlation (r=0,8; p<0,05) with March-September mean temperature. Although only end of March is characterized as period with stable positive temperatures we decided to use whole month as beginning vegetation period and September as the end. Calibration explains 63% of variance in the instrumental climate records (1957-2005). According to our reconstruction the coolest vegetation period in the Caucasus was occurred in 1817 (2-years lag response to Tambora eruption). Reconstructed temperature coincides well with the one of Piatigorsk meteostation that located in more than 200 km apart from investigated area at the altitude of 500 m a.s.l. It allows to use reconstruction in a local as well as regional scale.