A modern pollen–climate calibration set based on lake sediments from the Tibetan Plateau and its application to a Late Quaternary pollen record from the Qilian Mountains

Aim: Fossil pollen spectra from lake sediments on the Tibetan Plateau have been used for qualitative climate reconstruction, but no modern pollen-climate calibration set based on lake sediments is available to infer past climate quantitatively. This study aims to develop such a dataset and apply it to fossil data. Location: The Tibetan Plateau, between 30 and 40 degrees N and 87 and 103 degrees E. Methods: We collected surface sediments from 112 lakes and analysed them palynologically. The lakes span a wide range of mean annual precipitation (P-ann; 31-1022 mm), mean annual temperature (T-ann; -6.5 to 1 degrees C), and mean July temperature (T-July; 2.6-19.7 degrees C). Redundancy analysis showed that the modern pollen spectra are characteristic of their respective vegetation types and local climate. Transfer functions for P-ann, T-ann and T-July were developed with weighted averaging partial least squares. Model performance was assessed by leave-one-out cross-validation. Results: The root mean square errors of prediction (RMSEP) were 104 mm (P-ann), 1.18 degrees C (T-ann) and 1.17 degrees C (T-July). The RMSEPs, when expressed as percentages of the gradient sampled, were 10.6% (P-ann), 15.7% (T-ann) and 11.9% (T-July). These low values indicate the good performance of our models. An application of the models to fossil pollen spectra covering the last c. 50 kyr yielded realistic results for Luanhaizi Lake in the Qilian Mountains on the north-eastern Tibetan Plateau (modern P-ann 480 mm; T-ann-1 degrees C). T-ann and P-ann values similar to present ones were reconstructed for late Marine Isotope Stage 3, with minimum values for the Last Glacial Maximum (c. 300 mm and 2 degrees C below present), and maximum values for the early Holocene (c. 70 mm and 0.5 degrees C greater than present). Main conclusions: The modern pollen-climate calibration set will potentially be useful for quantitative climate reconstructions from lake-sediment pollen spectra from the Tibetan Plateau, an area of considerable climatic and biogeographical importance.

[1]  Xiu-ping Liu,et al.  Mollusk record of millennial climate variability in the Loess Plateau during the Last Glacial Maximum , 2002 .

[2]  W. Broecker,et al.  Correlations between climate records from North Atlantic sediments and Greenland ice , 1993, Nature.

[3]  Fahu Chen,et al.  Pollen transport in the Shiyang River drainage, arid China , 2003 .

[4]  Wenying Wang,et al.  Distribution and Species Diversity of Plant Communities along Transect on the Northeastern Tibetan Plateau , 2006, Biodiversity & Conservation.

[5]  Zhuo Zheng,et al.  Characteristics of the modern pollen distribution and their relationship to vegetation in the Xinjiang region, northwestern China , 2009 .

[6]  H. J. B. Birks,et al.  Pollen-based reconstructions of late-Quaternary climate in Eurpoe - progress, problems, and pitfalls. , 2005 .

[7]  H. Birks,et al.  D.G. Frey and E.S. Deevey Review 1: Numerical tools in palaeolimnology – Progress, potentialities, and problems , 1998 .

[8]  H. Birks,et al.  Younger Dryas and Allerød summer temperatures at Gerzensee (Switzerland) inferred from fossil pollen and cladoceran assemblages , 2000 .

[9]  Simon Brewer,et al.  Climatic changes in Eurasia and Africa at the last glacial maximum and mid-Holocene: reconstruction from pollen data using inverse vegetation modelling , 2007 .

[10]  H. Birks,et al.  The development of the aquatic ecosystem at Kråkenes Lake, western Norway, during the late glacial and early Holocene - a synthesis , 2000 .

[11]  H. Birks,et al.  July mean temperature and annual precipitation trends during the Holocene in the Fennoscandian tree-line area: pollen-based climate reconstructions , 2001 .

[12]  U. Herzschuh,et al.  Holocene vegetation and climate of the Alashan Plateau, NW China, reconstructed from pollen data , 2004 .

[13]  Keith Bennett,et al.  Quaternary pollen analysis: recent progress in palaeoecology and palaeoclimatology , 2003 .

[14]  Ge Yu,et al.  Reconstruction of the 30–40 ka bp enhanced Indian monsoon climate based on geological records from the Tibetan Plateau , 2001 .

[15]  E. Mosley‐Thompson,et al.  Tropical Climate Instability: The Last Glacial Cycle from a Qinghai-Tibetan Ice Core , 1997 .

[16]  Ge Yu,et al.  Modern pollen samples from alpine vegetation on the Tibetan Plateau , 2002 .

[17]  Jürgen Böhner,et al.  General climatic controls and topoclimatic variations in Central and High Asia , 2006 .

[18]  Richard J. Telford,et al.  Evaluation of transfer functions in spatially structured environments , 2009 .

[19]  Qinghai Xu,et al.  A transfer-function model developed from an extensive surface-pollen data set in northern China and its potential for palaeoclimate reconstructions , 2007 .

[20]  Zhuo Zheng,et al.  Vegetational and climatic significance of modern pollen rain in northwestern Tibet , 1999 .

[21]  U. Herzschuh,et al.  Temperature variability and vertical vegetation belt shifts during the last ∼50,000 yr in the Qilian Mountains (NE margin of the Tibetan Plateau, China) , 2006, Quaternary Research.

[22]  M. Ohsawa,et al.  Vertical vegetation zones along 30° N latitude in humid East Asia , 1996, Vegetatio.

[23]  M. Hill,et al.  Detrended correspondence analysis: an improved ordination technique , 1980 .

[24]  A. Bräuning,et al.  Summer temperature and summer monsoon history on the Tibetan plateau during the last 400 years recorded by tree rings , 2004 .

[25]  Sun Xiangjun,et al.  Establishment of Transfer Functions of the Pollen-Climatic Factors in Northern China and the Quantitative Climatic Reconstruction at DJ Core , 1997 .

[26]  Sun Xiangjun,et al.  Numerical Characteristics of Pollen Assemblages of Surface Samples from the West Kunlun Mountains , 1993 .

[27]  J. Overpeck,et al.  Quantitative relationships between modern pollen rain and climate in the Tibetan Plateau , 2006 .

[28]  Qinghai Xu,et al.  Pollen‐vegetation relationship and pollen preservation on the Northeastern Qinghai‐Tibetan Plateau , 2005 .

[29]  Stephen T. Jackson,et al.  MODERN ANALOGS IN QUATERNARY PALEOECOLOGY: Here Today, Gone Yesterday, Gone Tomorrow? , 2004 .

[30]  Richard J. Telford,et al.  The secret assumption of transfer functions: problems with spatial autocorrelation in evaluating model performance , 2005 .

[31]  U. Herzschuh.  Palaeo-moisture evolution in monsoonal Central Asia during the last 50,000 years , 2006 .

[32]  Steve Juggins,et al.  Weighted averaging partial least squares regression (WA-PLS): an improved method for reconstructing environmental variables from species assemblages , 1993, Hydrobiologia.

[33]  J. Guiot,et al.  Last Glacial Maximum climate of the former Soviet Union and Mongolia reconstructed from pollen and plant macrofossil data , 1999 .

[34]  K. Gajewski,et al.  Modern pollen data from North America and Greenland for multi-scale paleoenvironmental applications , 2005 .

[35]  R. L. Edwards,et al.  A High-Resolution Absolute-Dated Late Pleistocene Monsoon Record from Hulu Cave, China , 2001, Science.

[36]  U. Herzschuh,et al.  An ostracod-conductivity transfer function for Tibetan lakes , 2007 .

[37]  Q. Hu,et al.  Regulation of Tibetan Plateau heating on variation of Indian summer monsoon in the last two millennia , 2005 .

[38]  F. Riedel,et al.  A late Quaternary lake record from the Qilian Mountains (NW China): lake level and salinity changes inferred from sediment properties and ostracod assemblages , 2005 .

[39]  D. Jarvis,et al.  A comparison of modern pollen rain and vegetation in southwestern Sichuan Province, China , 1992 .

[40]  M. Lyford,et al.  Pollen dispersal models in Quaternary plant ecology: Assumptions, parameters, and prescriptions , 2008, The Botanical Review.

[41]  F. Riedel,et al.  A late Quaternary lake record from the Qilian Mountains (NW China): evolution of the primary production and the water depth reconstructed from macrofossil, pollen, biomarker, and isotope data , 2005 .

[42]  Jun Liu,et al.  Palaeovegetation of China: a pollen data‐based synthesis for the mid‐Holocene and last glacial maximum , 2000 .

[43]  H. Birks,et al.  A modern pollen–climate calibration set from northern Europe: developing and testing a tool for palaeoclimatological reconstructions , 2004 .

[44]  Yan Zhao,et al.  Modern pollen representation of source vegetation in the Qaidam Basin and surrounding mountains, north-eastern Tibetan Plateau , 2009 .

[45]  P. Tarasov,et al.  Quantitative pollen-based climate reconstruction in central Japan: application to surface and Late Quaternary spectra , 2002 .

[46]  T. Korsman,et al.  Diatom transfer-functions for quantifying past air temperature, pH and total organic carbon concentration from lakes in northern Sweden , 2000 .

[47]  中国地図出版社,et al.  The national physical atlas of China , 1999 .

[48]  Martin T. Sykes,et al.  Physiological Significance of Low Atmospheric CO2 for Plant–Climate Interactions , 1999, Quaternary Research.

[49]  H. Willems,et al.  Organic-walled dinoflagellate cyst assemblages in the tropical Atlantic Ocean and oceanographical changes over the last 140 ka , 2000 .

[50]  Simon Brewer,et al.  Dominant factors controlling glacial and interglacial variations in the treeline elevation in tropical Africa , 2007, Proceedings of the National Academy of Sciences.