摘要
利用神龙架林区两个样点的巴山冷杉（Abies fargesii Franch）建立了一条新的可靠的树轮年表.该年表与区域2月、3月、4月和6月的温度呈显著正相关关系（P＜0.01）,其中年表与2～6月的平均温度相关性最高达到了0.64（P＜0.01）.基于该年表重建了神农架地区过去172年来的冬春季温度变化,发现过去170多年来共有6个低温时段,分别为1848～1859年、1869～1874年、1888～1900年、1927～1932年、1938～1973年和1979～ 1994年.与研究区周边树轮记录的冬春季温度变化的对比发现,1870s之前本文树轮记录的低温事件与秦岭山脉东部地区树轮所记录的低温事件较一致,在1920s以后则与大别山地区及江西湖南地区树轮所记录的低温事件较一致.通过对比3条重建序列的趋势变化发现,神农架地区的温度开始变暖的时间要早于大别山地区与江西湖南地区,且升温的幅度也更大.最后通过对区域冷期与暖期500hPa高度场的合成分析得出,区域低温事件主要受乌拉尔高压的影响.
A robust tree-ring chronology was developed, based on 98 cores from 59 Abies fargesii Franch trees, for the Shennongjia Mountain area of Central China. All the tree species are typically found growing above 2000m a.s.1. The Shennongjia Mountains, known as the ＂top of Central China＂, are located in the boundary region between the subtropical and warm-temperature China and are mainly influenced by Asian monsoonal climate patterns. Tree-ring samples are collected from two close sites （approximately 4 kilometers apart） in the Shennongjia Mountains. The two sampling sites are Shennongding （31°27′N, 110°16′E） and Taiziya （ 31°27′N, 110°11′E）, and both are almost located at the tree line, where tree growth is generally sensitive to temperature change. As the meteorological stations are basically situated in the river/mountain valleys at elevations ranging from 300m a.s.1, to 400m a.s.1, and are less representative of local climate processes than stations situated at higher elevation. Therefore, we extract precipitation and temperature records for the nearest grid point from the CRU TS 3.2 dataset with a resolution of 0.5°×0.5°. Climate-growth relationships are evaluated by correlating tree rings with the average rainfall and temperature records of the grid point from the previous September to the current August. This chronology exhibits significant （at 0.01 level） positive correlations with temperature in February （0.387）, March （0.495）, April （0.477） and June （0.358）. No significant Pearson correlation is found between tree rings and precipitation in any month. The highest correlation is observed between tree growth and February-June average temperature （0.64）, suggesting tree rings tend to manifest the winter-spring temperature signals. Accordingly, the February-June average temperature was reconstructed back to 1842 using these tree rings, explaining 40.96% of the instrumental variance. The lO-year low passed series of the reconstruction reveals that six cold per
出处
《第四纪研究》
CAS
CSCD
北大核心
2015年第5期1145-1154,共10页
Quaternary Sciences
基金
教育部博士点基金项目（批准号：20120211110041）和国家自然科学基金项目（批准号：41401047）共同资助致谢真诚感谢审稿专家建设性的修改意见,使文章得以发表.
关键词
神农架
树木年轮
冬春温度
大气环流
Shennongjia, tree rings, winter-spring temperature, circulation pattern
