Drought signals in tree-ring stable oxygen isotope series of Qilian juniper from the arid northeastern Tibetan Plateau
Drought signals in tree-ring stable oxygen isotope series of Qilian juniper from the arid northeastern Tibetan Plateau
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DOI：
10.1016/j.gloplacha.2014.12.002
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发表时间：
2015-02
影响因子：
3.9
通讯作者：
C. Qin;Bao Yang;A. Bräuning;Jussi Grießinger;Jakob Wernicke
中科院分区：
文献类型：
--
作者：
C. Qin;Bao Yang;A. Bräuning;Jussi Grießinger;Jakob Wernicke
树轮α-纤维素的稳定氧同位素（δ18O）在古气候研究中具有重要作用。青藏高原东北部是一个对气候变化特别敏感的地区，其树木年轮档案的δ18O研究明显缺乏。目前存在的少数年轮δ18O年代学是在制备和分析之前，通过汇集来自不同树木的同一年的木材材料获得的。尽管这种方法具有时间和成本效益，但它可能阻碍对氧同位素信号内部变率变化的分析和对由此产生的气候重建的更深入理解。选取东北高原1951—2011年的5棵祁连刺柏（Sabina przewalskii Kom.），对单树分析获得的稳定氧同位素组成记录中包含的气候信号进行了研究。5个个体δ18O序列间的相关关系极显著（mean = 0.59, n = 59,p= 0.01），但5个个体δ18O序列间的均值差异显著。干旱/水文气候触发的气候参数（PDSI、降水）与各δ18O序列呈显著负相关。空间相关图显示树木年轮δ18O与印度洋海表温度呈负相关，青藏高原北部和南部水汽条件呈负相关。研究结果可为今后物种稳定氧同位素/气候信号的研究提供参考。przewalskii卡尔玛. .
For the mechanistic understanding of hydroclimate variability, stable oxygen isotopic ratios (δ18O) of tree-ring α-cellulose can play a key role in paleoclimatic research. On the north-east Tibetan Plateau (TP), a region particularly sensitive to climate change, there exists a distinct lack of δ18O research in tree-ring archives. The few currently existing tree-ring δ18O chronologies were obtained by pooling the wood material from the same year from different trees prior to preparation and analysis. Although this method is time and cost efficient, it might impede the analysis of changes within the internal variability of oxygen isotope signals and a deeper understanding of the resulting climate reconstruction. We selected five Qilian juniper (Sabina przewalskii Kom.) trees covering the period 1951–2011 on the north-east TP to investigate the climate signals contained in stable oxygen isotopic composition records obtained using single tree analysis. Although the inter-series correlation between the five individual δ18O series indicates a highly significant relationship (meanr= 0.59, n = 59,p= 0.01), the five individual δ18O series show significantly differently mean values. We found significant negative correlations between drought/hydroclimatically triggered climate parameters (PDSI, precipitation) and each of the individual δ18O series. Spatial correlation maps indicate negative correlation of tree-ring δ18O and Indian Ocean sea surface temperatures, and inverse correlation patters of moisture conditions on the northern and southern TP. Our results provide a reference for future research on stable oxygen isotope/climate signals in the speciesS. przewalskii Kom..