Tree rings reveal hydroclimatic fingerprints of the Pacific Decadal Oscillation on the Tibetan Plateau
Predicting hydroclimatic changes on the Tibetan Plateau (TP) is crucial for managing water and ecosystems for the well-being of millions of people. Our understanding of the synoptic conditions on the TP is, however, still limited due to the paucity of meteorological measurements and proxy-based, high-resolution climate reconstructions. Here, we use state-of-the-art dendroclimatological techniques to investigate the paleoclimatic potential of drought-sensitive Picea likiangensis var. balfouriana forests between 4000 and 4500 m asl on the southeastern TP (SETP). The newly developed tree-ring width chronology correlates significantly with yearly changes in regional relative air humidity (RH) (r = 0.85, P < 0.001, 1978–2011). A new 407-year-long reconstruction of RH over the hydrological year from previous year August to July of the year of ring formation shows that, despite the generally humid conditions, four of the ten driest years are observed in the twentieth century with 1983 having been the driest. On the other hand, seven out of the ten most humid years were found in the eighteenth century. Our reconstruction reveals that the Pacific Decadal Oscillation (PDO) is the dominant climate driver at multi-decadal scales, but the relationships are not stable over time, with unknown underlying mechanisms. Although our study demonstrates the importance of the PDO for hydroclimate projections on the TP, caution is advised when considering only its most recent fluctuations.
KeywordsClimate dynamics Dendroclimatology Drought extremes Hydroclimate Proxy reconstruction Relative humidity Tree rings
This research was supported by the Natural Science Foundation of China (Grants Nos. 31330015 and 41771060) and the China Scholarship Council (No. 201770490418). The climate data were obtained from the weather information centre of the China Meteorological Administration. We are grateful to the Tibetan Forestry Bureau for permitting field sampling and the field work team for collecting tree-ring samples. We are also grateful to Prof. Qi-Bin Zhang for commenting on the early version of the manuscript and to Erin Gleeson for editing English texts.
Compliance with ethical standards
Conflict of interest
The authors have declared no conflicts of interest for this article.
- Allen RG, Pereira LS, Raes D, Smith M (1998) Crop evapotranspiration—guidelines for computing crop water requirements. Food and Agriculture Organization of the United Nations. Rome, Italy (ISBN 92-5-104219-5) Google Scholar
- Beguería S, Vicente-Serrano SM (2017) SPEI: calculation of the standardised precipitation-evapotranspiration index R package version, vol 17. https://CRAN.R-project.org/package=SPEI. Accessed 26 June 2018
- Cook ER, Kairiukstis LA (1990) Methods of dendrochronology: applications in the environmental sciences. Kluwer Academic Press, DordrechtGoogle Scholar
- Fritts HC (1976) Tree rings and climate. Academic Press, London, UK (ISBN 0122684508) Google Scholar
- Grießinger J, Bräuning A, Helle G, Hochreuther P, Schleser G (2017) Late Holocene relative humidity history on the southeastern Tibetan plateau inferred from a tree-ring δ18O record: recent decrease and conditions during the last 1500 years. Quatern Int 430:52–59. https://doi.org/10.1016/j.quaint.2016.02.011 Google Scholar
- Holmes RL (1983) Computer-assisted quality control in tree-ring data and measurement. Tree-Ring Bull 43:69–78Google Scholar
- Imtiaz R, Eric S, James RM (2013) Amplified warming projections for high altitude regions of the northern hemisphere mid-latitudes from CMIP5 models. Environ Res Lett 8:024040Google Scholar
- Kullman L (2002) Rapid recent range-margin rise of tree and shrub species in the Swedish Scandes. J Ecol 90:68–77Google Scholar
- Liang EY, Shao XM, Xu Y (2009) Tree-ring evidence of recent abnormal warming on the southeast Tibetan Plateau. Theor Appl Climatol 98:9–18Google Scholar
- Michaelsen J (1987) Cross-validation in statistical climate forecast models. J Appl Meteorol Climatol 26:1589–1600. https://doi.org/10.1175/1520-0450(1987)026<1589:CVISCF>2.0.CO;2 Google Scholar
- Nakamura H, Lin G, Yamagata T (1997) Decadal climate variability in the North Pacific during the recent decades. B Am Meteorol Soc 78:2215–2226 https://doi.org/10.1175/1520-0477(1997)078%3C2215:Dcvitn%3E2.0.Co;2 Google Scholar
- R Core Team (2018) R: a language and environment for statistical computing. R Foundation for Statistical Computing. Vienna, Austria. http://www.R-project.org/.URL. Accessed 6 June 2018
- Tibet Archive (1990) Tibet disasters records: hail, frost and insect disasters (in Chinese). China Tibetology Publishing House, BeijingGoogle Scholar
- Wigley TML, Briffa KR, Jones PD (1984) On the average value of correlated time series, with applications in dendroclimatology and hydrometeorology. J Clim Appl Meteorol 23:201–213 https://doi.org/10.1175/1520-0450(1984)023%3C0201:OTAVOC%3E2.0.CO;2 Google Scholar
- Will RE, Wilson SM, Zou CB, Hennessey TC (2013) Increased vapor pressure deficit due to higher temperature leads to greater transpiration and faster mortality during drought for tree seedlings common to the forest–grassland ecotone. New Phytol 200:366–374. https://doi.org/10.1111/nph.12321 Google Scholar
- Winkler MG, Wang PK (1993) The Late-Quaternary vegetation and climate of China. In: Wright HE (ed) Global climates since the last glacial maximum. University of Minnesota Press, Minneapolis, pp 221–261Google Scholar
- Xu L-X (2001) Ecology episode of Xi Zang 50 year. National Publishing house, Beijing (in Chinese)Google Scholar