Tree-ring based winter temperature reconstruction for the lower reaches of the Yangtze River in southeast China

Two robust tree-ring width chronologies were developed for the western Tianmu Mountains and the Xianyu Mountains of southeast China. Both chronologies were significantly correlated with each other and were arithmetically averaged to build a regional chronology (RC). The RC had significant and positive correlations with winter temperature before the growing season. Based on this relationship, the average temperatures of the previous December to the current March were reconstructed using the RC chronology for the period 1852 to 2006. The temperature reconstruction was significantly correlated with the winter half-year temperature in the eastern Qinling Mountains of central China, 720 km west of the study region, suggesting a large-scale coherence of winter temperature variability. The reconstruction corresponds well with an East Asian winter monsoon (EAWM) index in extreme years and reflects the strong influences of the EAWM in this study region. Thus, there is great potential to use tree-ring chronologies to reconstruct past climate change in southeast China, where little dendroclimatic work has been done until now.