Scarcity of high-resolution proxy records has hindered our understanding of long-term climate variations and their mechanism in climate-sensitive regions such as the Tibetan Plateau (TP). In this study, we present a winter minimum temperature (Tmin) reconstruction for the past 351 years (1648–1998) based on a composite tree ring width chronology from three upper treeline sites in the Gongga Mountains, southeastern TP. Despite a loss of sensitivity to winter Tmin after the 1990s, tree growth agrees well with previous December to current March (pDec-cMar) Tmin during 1953–1998, and a regression model based on climate-tree growth relationship over this period explains 52% of the instrumental Tmin variance. The resulting reconstruction exhibits three major cold (1670–1745, 1805–1853, and 1877–1949) and four major warm (1648–1669, 1746–1804, 1854–1876, and 1950–1998) periods over the past four centuries. Long-term winter Tmin variations in the Gongga Mountains have high coherence with those represented by temperature reconstructions in the nearby regions. Together, they indicate close association of the reconstructed warm/cold periods with the positive/negative phases of the Atlantic Multidecadal Oscillation (AMO), suggesting that the AMO may have been a key driving force affecting regional climate over the past few centuries.

高分辨率代理记录的稀缺性阻碍了我们对气候敏感地区（如青藏高原）的长期气候变化及其机制的理解。在这项研究中，我们基于TP东南部贡嘎山的三个上林线地点的复合年轮宽度年表，提出了过去351年（1648–1998年）的冬季最低温度（Tmin）重建。尽管在1990年代后对冬季的Tmin失去了敏感性，但树木的生长与1953-1998年之前的12月至当前的3月（pDec-cMar）Tmin吻合得很好，并且基于此期间气候树生长关系的回归模型解释了52％仪器的Tmin方差。重建结果显示出三个主要的寒冷（1670–1745、1805–1853和1877–1949）和四个主要的温暖（1648–1669、1746–1804、1854–1876，和1950年至1998年）。贡嘎山区的冬季长期Tmin变化与附近地区温度重建所代表的变化具有高度的连贯性。它们共同表明，重建的暖/冷期与大西洋多年代际涛动（AMO）的正/负相位密切相关，这表明AMO可能是过去几个世纪以来影响区域气候的主要驱动力。