以树轮宽度重建公元1558年以来华山5-6月平均温度及20世纪中后期升温

TREE-RING WIDTH BASED MAY ～ JUNE MEAN TEMPERATURE RECONSTRUCTION FOR HUASHAN MOUNTAIN SINCE A. D.1558 AND 20TH CENTURY WARMING

通过对秦岭东端华山地区油松树木年轮宽度序列的分析研究,探讨了华山地区油松对气候环境响应的敏感性,结果表明在华山地区油松对气温和降水的响应均高于华山松,与5～6月平均温度相关较高,且通过了0.01显著性信度检验。在此基础上,我们重建了华山地区1558～2006年间5～6月的平均温度,重建序列的方差解释量达到41%。结果显示:华山过去449年中,大部分年份5～6月平均温度在平均值附近波动,变幅不大;重建序列可与秦岭南五台5～7月温度序列进行良好对比,其年际间相关系数达到了0.49(N=246,p<0.0001)。华山地区20世纪20～30年代初的暖期略偏低;20世纪30年代中期至50年代是整个重建时段中低温持续时间较长的时段;20世纪60年代之后,气温波动平缓;从20世纪70年代开始快速升温,对全球变暖有较强响应。

Global warming was widely accepted in the 20th century,but there were diversities in different regions. This paper analyzed the background of the regional response to global change in the Huashan region of Eastern Qinling Mountains by tree ring.Temperature changes inferred from the proxy data, especially from tree-ring data have been studied on the Northern Hemisphere. In this paper, we provided a tree-ring-width chronology of A. D. 1528-2006 of Pinus tabulaeformis in Huashan（34°28′N, 110°04′E）, the eastern end of Qinling Mountains, which was an important geographic demarcation line in the east of Central China. Correlation analysis showed that the tree-ring-width chronology significantly correlated with the average temperature of May - June. Based on this result, we reconstructed the mean May -June temperature of A. D. 1558-2006 using tree-ring index in the Huashan region. The explained variance reached 41%, and 40% after adjusting degree of freedom. Both“Jackknife” and “Bootstrap” methods were used to estimate the reliability of the regression function. All these statistics based on above two methods were close, which displayed the function was reliable.The reconstruction displayed the fluctuation of temperature in this region. There were 120 years of high temperature, accounted for 26.7% of the total reconstructed series, and 129 years of low temperature, accounted for 28.7%.The frequency of high temperature year and low temperature year was almost equal over all the reconstructed period.And there were two obvious long warm periods,i.e. ,A.D.1698 - 1708 and A.D.1749-1777. The long-low-temperature period reconstructed occurred from the early 1930s to 1950s of the 20th century, with the lowest temperature of 12.0℃ occurring in 1933. Since the 1970s, temperature has been increased rapidly, which agreed well with global warming of the late 20th century.The reconstructed temperature of Huashan was significantly correlated with the reconstructed temperature of Nanwutai（r=0.49 ,N =246 ,p〈0.0001）. Both can also be well compared with an 11-year moving average（r=0.41,N= 236, p〈0.0001）. Two curves showed a synchronous warming trend, which proved our result to be reliable. Thus,Pinus tabulaeformis has a great potential for temperature reconstruction in this region.