Negligible local-factor influences on tree ring cellulose δ18O of Qilian juniper in the Animaqing Mountains of the eastern Tibetan Plateau

• Published in: Tellus. Series B, Chemical and physical meteorology Vol. 69; no. 1; p. 1391663
• Main Authors: Xu, Chenxi, Shao, Xuemei, An, Wenling, Nakatsuka, Takeshi, Zhang, Yong, Sano, Masaki, Guo, Zhengtang
• Format: Journal Article
• Language: English
• Published: Stockholm Taylor & Francis 01.01.2017; Ubiquity Press; Stockholm University Press
• Subjects: Altitude; altitude effect; Altitude effects; Cellulose; Correlation; Data; Elevation; Isotopes; juvenile effect; Mountains; Oxygen; Oxygen isotopes; Precipitation; Qilian juniper; Standard deviation; Tibetan Plateau; Tree growth; tree ring oxygen isotopes; Tree rings; Trees; Tibetan Plateau
• ISSN: 0280-6509; 1600-0889
• DOI: 10.1080/16000889.2017.1391663

Tree ring cellulose oxygen isotopes (δ 18 O) were measured on 21 trees of Qilian juniper from the Animaqing Mountains, Tibetan Plateau, to investigate intra- and inter-tree variability, potential juvenile and elevation effects and climatic implications. There are no significant differences in mean and standard deviation of tree ring δ 18 O values at different heights in individual trees. Tree ring δ 18 O values from different directions show a high degree of coherence. The mean and standard deviation for vertical and circumferential δ 18 O time series are very similar, and δ 18 O data from different heights and directions are highly correlated (r > 0.88). The δ 18 O values of young trees are lower than those of old trees in the first 10 years of tree growth. Tree ring δ 18 O data from five different altitudes are highly correlated (r > 0.88) and share similar climatic signals. As such, an altitude effect on tree ring δ 18 O is not observed. Our results indicate that samples from one site, regardless of sampling height, direction or altitude, can be used to reconstruct a long-term δ 18 O record. Tree ring δ 18 O data from the Animaqing Mountains show a significant negative correlation (r = −0.67; p < 0.001) with May-July regional precipitation and appear to be a promising proxy for precipitation reconstruction.