资源环境科技发展态势分析平台

Owing to a lack of available long-term climatic records, data related to past climatic variability throughout the Tibetan Plateau remains limited. In this study, we found that Qilian juniper tree growth was significantly and positively correlated (p<0.001) to yearly mean temperatures in the northeastern margin of the Tibetan Plateau. We developed an annual mean temperature reconstruction from year 1740 CE based on growth-climate relationships in the study area. Our reconstruction accounted for 53.9% of total variance from 1956 to 2012 (the calibration period). Through this reconstruction, we were successfully able to capture recent abrupt climate change events that generally agreed with other temperature-sensitive tree-ring reconstructions on both regional and hemisphere scales under a decadal timescale. Periods from 1820 to 1830, 1855 to 1890, and 1960 to 1985 CE corresponded to cold periods in the reconstruction, while the 1740s and periods from 1795 to 1815 and from 1990 to 2012 CE corresponded to relatively warm periods. We also detected increased interannual change variability in annual mean temperatures since the 1980s, which could be related to increasing variability in the East Asian winter monsoon as well as the rapid climate warming that has occurred since this time. From these reconstructed temperatures, we were successfully able to capture the occurrences of large volcanic events in China as well as five historic volcanic events outside China that had global implications on climate variability and that resulted in planetary cooling during the period from 1740 to 2012 CE. This in turn suggested that these volcanic events would have had short-lived impacts (approximately from 1 to 3 years) on temperature variation in the study area. The aim of this study was to provide a perspective in which to explore the mechanisms that simultaneously influence tree rings and climate.