北京地区近70年来白皮松树轮纤维素的碳稳定同位素与气候变化

CLIMATIC RECONSTRUCTION FROM THE TREERINGδ^(13)C VALUES OF PINUS BUNGEANA DURING THE PAST 70 YEARS IN BEIJING

对采自北京大学校园内的白皮松(Pinusbungeana)树轮α-纤维素的δ13C进行了分析,结合北京气象台的气象记录,建立树轮δ13C与气候各要素的回归方程,重建值与观测值吻合较好,表明北京地区树轮α-纤维素的碳稳定同位素与1928—1999年3—9月的平均气温及6—9月的平均降雨量显著相关,重δ13C对应于3—9月的低温和6—9月的少雨,轻δ13C对应于3—9月的高温和6—9月的多雨,而3—9月的温度正好是适宜树木生长的光合作用所需要的最佳温度,6—9月正好是一年中降雨最充沛的时期。由此认为:树轮δ13C值与生长季节的降水和气温密切相关,可以考虑作为季风盛行地区的气候替代性指标,在一定程度上反映了季风盛行区白皮松树轮纤维素碳稳定同位素与气候因子的关系。

For δ13C of αcellulose of Pinus bungeana,tree rings are analyzed in Peking University. Combined with the records of Beijing Meteorological Station, the regressional equations of δ13C and climate factors are constructed, then the parameters are reconstructed. The calculated values are identical with the true values. The results indicate that δ13C values of tree ring αcellulose in Beijing area from 1928 to 1999 show significant correlation with average temperature from March to September and average precipitation rate from June to September during the past 70 years. The heavy δ13C is corresponding to low temperature from March to September and little precipitation from June to September, the light δ13C is corresponding to high temperature from March to September and much precipitation from June to September. In this article, we show that δ13C value of tree ring αcellulose in Beijing is closely related to temperature and precipitation during the growth, and it can be used as a substitute index of climate. To a certain extent, the study shows that there is an important relationship between δ13C values of tree ring αcellulose and climatic factor in monsoonal area. 