Tree-ring based February-April precipitation reconstruction for the lower reaches of the Yangtze River, southeastern China

Abstract

February–April drought strongly affects agriculture and socio-economics in southeastern China, yet its long-term variability has not been assessed due to the shortness of instrumental records. In this study, we reported a 168-year tree-ring width chronology from a steep, low-elevation site with thin soil layers in the Xianxia Mountains, southeastern China. Contrary to the existing chronologies that are mostly temperature sensitive, this chronology contained a strong February–April precipitation signal, indicating great potential for tree-ring based precipitation reconstructions in southeastern China. The reconstruction explained 47.8% of the instrumental variance during 1951–2012. The full reconstruction indicated that there were 3 dry periods (1873–1896, 1924–1971, 1995–2012) and 2 wet periods (1856–1872, 1972–1994) during 1856–2013. The extreme drought in 2011 was not unprecedented for the past 168 years, and the recent severe droughts may be part of interdecadal variations in regional February–April precipitation. Our results also suggested that February–April precipitation in southeastern China was highly influenced by the tropical Pacific climate system, in particular El Niño-Southern Oscillation (ENSO).