Response to Winter Precipitation in Ring-Width Chronologies of Pinus Sylvestris L. from the Northwestern Siberian Plain, Russia

Abstract

Six mean ring-width tree-ring chronologies were constructed for living Scots pine (Pious sylvestris L.), growing near the species' upper and northern limits in the area between the Ob River and the subpolar Ural Mountains in Russia. All ring-width series were standardized by fitting cubic smoothing splines and chronologies were constructed as biweight robust means. The six chronologies ranged from 181 to 276 years in length. Response function analysis showed all chronologies to have negative responses to winter precipitation. Most chronologies also showed positive, but relatively low responses to temperatures of the current and previous summer. Total October-May precipitation was reconstructed back to A.D. 1843 using the lagged and unlagged chronologies as candidate predictors. In addition to reflecting an unstable and time-varying growth-climate link, moderate verification results may partly be due to problems with short verification periods. The reconstruction contains almost equal amounts of high-frequency (<8 years) and low-frequency ( >8 years) variations, among them a significant 30-year variation. The precipitation signal may add an important aspect to reconstructing paleoclimatic fluctuations in the northern hemisphere. Continuing work with the Scots pine from this area depends on improving the quality of a precipitation reconstruction and finding older living and subfossil wood.