TY - JOUR A1 - Tian, Fang A1 - Herzschuh, Ulrike A1 - Telford, Richard J. A1 - Mischke, Steffen A1 - Van der Meeren, Thijs A1 - Krengel, Michael T1 - A modern pollen-climate calibration set from central-western Mongolia and its application to a late glacial-Holocene record JF - Journal of biogeography N2 - AimFossil pollen spectra from lake sediments in central and western Mongolia have been used to interpret past climatic variations, but hitherto no suitable modern pollen-climate calibration set has been available to infer past climate changes quantitatively. We established such a modern pollen dataset and used it to develop a transfer function model that we applied to a fossil pollen record in order to investigate: (1) whether there was a significant moisture response to the Younger Dryas event in north-western Mongolia; and (2) whether the early Holocene was characterized by dry or wet climatic conditions. LocationCentral and western Mongolia. MethodsWe analysed pollen data from surface sediments from 90 lakes. A transfer function for mean annual precipitation (P-ann) was developed with weighted averaging partial least squares regression (WA-PLS) and applied to a fossil pollen record from Lake Bayan Nuur (49.98 degrees N, 93.95 degrees E, 932m a.s.l.). Statistical approaches were used to investigate the modern pollen-climate relationships and assess model performance and reconstruction output. ResultsRedundancy analysis shows that the modern pollen spectra are characteristic of their respective vegetation types and local climate. Spatial autocorrelation and significance tests of environmental variables show that the WA-PLS model for P-ann is the most valid function for our dataset, and possesses the lowest root mean squared error of prediction. Main conclusionsPrecipitation is the most important predictor of pollen and vegetation distributions in our study area. Our quantitative climate reconstruction indicates a dry Younger Dryas, a relatively dry early Holocene, a wet mid-Holocene and a dry late Holocene. KW - Central-western Mongolia KW - Lake Bayan Nuur KW - modern pollen KW - ordination KW - palaeoclimate reconstruction KW - palaeoecology KW - transfer functions KW - WA-PLS KW - Younger Dryas Y1 - 2014 U6 - https://doi.org/10.1111/jbi.12338 SN - 0305-0270 SN - 1365-2699 VL - 41 IS - 10 SP - 1909 EP - 1922 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Herzschuh, Ulrike A1 - Birks, H. John B. A1 - Mischke, Steffen A1 - Zhang, Chengjun A1 - Böhner, Jürgen T1 - 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 N2 - 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. Y1 - 2010 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0305-0270 U6 - https://doi.org/10.1111/j.1365-2699.2009.02245.x SN - 0305-0270 ER - TY - JOUR A1 - Cao, Xianyong A1 - Ni, Jian A1 - Herzschuh, Ulrike A1 - Wang, Yongbo A1 - Zhao, Yan T1 - A late quaternary pollen dataset from eastern continental Asia for vegetation and climate reconstructions set up and evaluation JF - Review of palaeobotany and palynology : an international journal N2 - A total of 271 pollen records were selected from a large collection of both raw and digitized pollen spectra from eastern continental Asia (70 degrees-135 degrees E and 18 degrees-55 degrees N). Following pollen percentage recalculations, taxonomic homogenization, and age-depth model revision, the pollen spectra were interpolated at a 500-year resolution and a taxonomically harmonized and temporally standardized fossil pollen dataset established with 226 pollen taxa, covering the last 22 cal lea. Of the 271 pollen records, 85% were published since 1990, with reliable chronologies and high temporal resolutions; of these, 50% have raw data with complete pollen assemblages, ensuring the quality of this dataset The pollen records available for each 500-year time slice are well distributed over all main vegetation types and climatic zones of the study area, making their pollen spectra suitable for paleovegetation and paleoclimate research. Such a dataset can be used as an example for the development of similar datasets for other regions of the world. KW - fossil pollen KW - eastern asia KW - pollen taxa KW - age-depth model KW - resampling Y1 - 2013 U6 - https://doi.org/10.1016/j.revpalbo.2013.02.003 SN - 0034-6667 VL - 194 IS - 13 SP - 21 EP - 37 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Wang, Yongbo A1 - Herzschuh, Ulrike A1 - Liu, Xingqi A1 - Korup, Oliver A1 - Diekmann, Bernhard T1 - A high-resolution sedimentary archive from landslide-dammed Lake Mengda, north-eastern Tibetan Plateau JF - Journal of paleolimnolog N2 - Lacustrine sediments have been widely used to investigate past climatic and environmental changes on millennial to seasonal time scales. Sedimentary archives of lakes in mountainous regions may also record non-climatic events such as earthquakes. We argue herein that a set of 64 annual laminae couplets reconciles a stratigraphically inconsistent accelerator mass spectrometry (AMS) C-14 chronology in a similar to 4-m-long sediment core from Lake Mengda, in the north-eastern Tibetan Plateau. The laminations suggest the lake was formed by a large landslide, triggered by the 1927 Gulang earthquake (M = 8.0). The lake sediment sequence can be separated into three units based on lithologic, sedimentary, and isotopic characteristics. Starting from the bottom of the sequence, these are: (1) unweathered, coarse, sandy valley-floor deposits or landslide debris that pre-date the lake, (2) landslide-induced, fine-grained soil or reworked landslide debris with a high organic content, and (3) lacustrine sediments with low organic content and laminations. These annual laminations provide a high-resolution record of anthropogenic and environmental changes during the twentieth century, recording enhanced sediment input associated with two phases of construction activities. The high mean sedimentation rates of up to 4.8 mm year(-1) underscore the potential for reconstructing such distinct sediment pulses in remote, forested, and seemingly undisturbed mountain catchments. KW - Earthquake KW - Landslide KW - Natural dam KW - Tibetan Plateau Y1 - 2014 U6 - https://doi.org/10.1007/s10933-012-9666-6 SN - 0921-2728 SN - 1573-0417 VL - 51 IS - 2 SP - 303 EP - 312 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Herzschuh, Ulrike A1 - Winter, Katja A1 - Wünnemann, Bernd A1 - Li, Shijie T1 - A general cooling trend on the central Tibetan Plateau throughout the Holocene recorded by the Lake Zigetang pollen spectra JF - Quaternary international : the journal of the International Union for Quaternary Research N2 - A 741-cm-long laminated sediment core, covering the last 10,800 years was collected from Lake Zigetang, central Tibetan Plateau (90.9 degrees E, 32.0 degrees N, 4560m a.s.l.), and analysed palynologically at 69 horizons. Biome reconstruction suggests a dominance of temperate steppe vegetation (mainly Artemisia and Poaceae) on the central Tibetan Plateau during the first half of the Holocene (10.8-4.4 cal. ka BP), while alpine steppes with desert elements (mainly Cyperaceae, Poaceae, Chenopodiaceae, and characteristic high-alpine herb families) tend to dominate the second half (4.4-0 cal. ka BP). The Artemisia/Cyperaceae ratio-a semi-quantitative measure for summer temperature-indicates a general cooling trend throughout the Holocene. Dense temperate steppe vegetation and maximum desert plant withdrawal, however, indicate that a suitable balance of wet and warm conditions for optimum vegetation growth likely occurred during the middle Holocene (7.3-4.4 cal. ka BP). Severe Early Holocene cold events have been reconstructed for 8.7-8.3 and similar to 7.4 cal. ka BP. (c) 2006 Elsevier Ltd and INQUA. All rights reserved. Y1 - 2006 U6 - https://doi.org/10.1016/j.quaint.2006.02.005 SN - 1040-6182 VL - 154 SP - 113 EP - 121 PB - Pergamon Press CY - Oxford ER -