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

2010 ◽  
Vol 37 (4) ◽  
pp. 752-766 ◽  
Author(s):  
Ulrike Herzschuh ◽  
H. J. B. Birks ◽  
Steffen Mischke ◽  
Chengjun Zhang ◽  
Jürgen Böhner
Keyword(s):  
Tibetan Plateau ◽  
Lake Sediments ◽  
Late Quaternary ◽  
Qilian Mountains ◽  
The Tibetan Plateau ◽  
Pollen Record ◽  
Modern Pollen ◽  
The Qilian Mountains

scholarly journals Late Quaternary paleoclimatic and geomorphological evolution at the interface between the Menyuan basin and the Qilian Mountains, northeastern Tibetan Plateau

2013 ◽  
Vol 80 (3) ◽  
pp. 534-544 ◽  
Author(s):  
Xianyan Wang ◽  
Dimitri Vandenberghe ◽  
Shuangwen Yi ◽  
Jef Vandenberghe ◽  
Huayu Lu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Late Quaternary ◽  
Ice Cores ◽  
Qilian Mountains ◽  
Mean Annual Temperature ◽  
The Tibetan Plateau ◽  
Northeastern Tibetan Plateau ◽  
Meltwater Runoff ◽  
The Qilian Mountains ◽  
Geomorphological Evolution

The Tibetan Plateau is regarded as an amplifier and driver of environmental change in adjacent regions because of its extent and high altitude. However, reliable age control for paleoenvironmental information on the plateau is limited. OSL appears to be a valid method to constrain the age of deposits of glacial and fluvial origin, soils and periglacial structures in the Menyuan basin on the northeastern Tibetan Plateau. Dating results show glaciers advanced extensively to the foot of the Qilian mountains at ~ 21 ka, in agreement with the timing of the global Last Glacial Maximum (LGM) recorded in Northern Hemisphere ice cores. Comparison with results from the eastern Tibetan Plateau suggests that the factor controlling glacial advance in both regions was decreased temperature, not monsoon-related precipitation increase. The areas of the Menyuan basin occupied by glacio-fluvial deposits experienced continuous permafrost during the LGM, indicated by large cryoturbation features, interpreted to indicate that the mean annual temperature was ≥ 7 °C lower than at present. Glacio-fluvial systems in the Menyuan basin aggraded and terraces formed during cold periods (penultimate glaciation, LGM, and possibly the Younger Dryas) as a response to increased glacial sediment production and meltwater runoff then.

scholarly journals Sub-recent Ostracoda from Qilian Mountains, NW China

2003 ◽  
Vol 22 (2) ◽  
pp. 137-138 ◽  
Author(s):  
Steffen Mischke ◽  
Ulrike Herzschuh ◽  
Harald Kürschner ◽  
Fahu Chen ◽  
Fei Meng ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Sea Level ◽  
Qilian Mountains ◽  
The Tibetan Plateau ◽  
Nw China ◽  
Mountainous Regions ◽  
History Of ◽  
Climatic History ◽  
The Qilian Mountains ◽  
First Time

Abstract. To our knowledge, the Qilian Mountains in NW China have been investigated with respect to Recent or sub-Recent ostracods for the first time. The Qilian Mountains (95–103°E/37–40°N) extend along the northeastern margin of the Tibetan Plateau reaching a maximum altitude of 5826 m above sea-level (m asl).In September 2001, surface mud from the bottom of various water bodies including brooks, rivers and small shallow meadow and oxbow pools were sampled at an altitude ranging from 2900 m to 3570 m asl. In addition, surface mud samples and short cores were obtained from the small (c. 1 km2) and shallow (<0.4 m) freshwater Lake Luanhaizi situated at about 3200 m asl.Ostracod valves were usually abundant in all of the 32 samples and comprised the taxa listed in Table 1, some of which are illustrated in Plate 1.The recorded taxa are mainly distributed in the holarctic realm but Fabaeformiscandona danielopoli and Ilyocypris echinata appear to be restricted to the cold mountainous regions in China (Huang, 1985; Wang &amp; Zhu, 1991; Sun et al., 1995; Yin &amp; Martens, 1997).Following the first survey, a 14 m long core was drilled in Lake Luanhaizi in January 2002 which is currently under multidisciplinary investigation to reconstruct the Holocene vegetation and climatic history of the Qilian Mountains.

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 ◽  
Vol 66 (1) ◽  
pp. 133-146 ◽  
Author(s):  
Ulrike Herzschuh ◽  
Harald Kürschner ◽  
Steffen Mischke
Keyword(s):  
Tibetan Plateau ◽  
Mixed Forest ◽  
Qilian Mountains ◽  
The Tibetan Plateau ◽  
Climate Conditions ◽  
Arboreal Pollen ◽  
Short Period ◽  
Alpine Shrub ◽  
Vegetation Belt ◽  
The Qilian Mountains

AbstractA 13.94-m-long sediment core, collected from a medium-sized lake in the Qilian Mountains (NE Tibetan Plateau, China), was analysed palynologically at 81 horizons. The interpretation of indicator taxa yielded various vertical shifts of the vegetation belts. These palaeovegetation results have been checked with lake surface pollen spectra from 8 lakes representing different altitudinal vegetation belts. Our main findings are the following: A short period of the late Marine Isotope Stage 3 (around ∼46,000 yr ago) was characterized by interglacial temperature conditions with a tree line above its present-day altitude. During the LGM, the vicinity of the lake was not covered by ice but by sparse alpine vegetation and alpine deserts, indicating that the climate was colder by ∼4–7°C than today. Markedly higher temperatures were inferred from higher arboreal pollen frequencies between ∼13,000 and ∼7,000 yr ago with a Holocene temperature optimum and a maximal Picea–Betula mixed-forest expansion between ∼9,000 and ∼7000 yr ago, when temperatures exceeded the present-day conditions by at least 1–2°C. Alpine steppes and meadows and sub-alpine shrub vegetation dominated around the lake since the middle Holocene, suggesting that vegetation and climate conditions were exceptionally stable in comparison to previous periods.

Spatial variability of tree growth along a latitudinal transect in the Qilian Mountains, northeastern Tibetan Plateau

2010 ◽  
Vol 40 (2) ◽  
pp. 200-211 ◽  
Author(s):  
Eryuan Liang ◽  
Xuemei Shao ◽  
Dieter Eckstein ◽  
Xiaohong Liu
Keyword(s):  
Tibetan Plateau ◽  
Spatial Variability ◽  
Tree Growth ◽  
Principal Components ◽  
Ring Width ◽  
Qilian Mountains ◽  
The Tibetan Plateau ◽  
Northeastern Tibetan Plateau ◽  
Latitudinal Transect ◽  
The Qilian Mountains

Little is known about the spatial variability in tree growth and its responses to climate on the Tibetan Plateau; however, such information is essential for improving predictions of forest ecosystem response to climatic change. A network of 16 ring width chronologies was developed along a latitudinal transect in the Qilian Mountains, northeastern Tibetan Plateau. A principal components analysis revealed that the residual chronologies had a positive loading on the first unrotated principal component (PC1). After rotation, PC1 yielded the highest loadings on the driest sites in the northwest and decreased to the south and to the east. PC2 was negatively correlated with altitude. Moisture availability was a dominant limiting factor for tree growth, and this dominance increased northwards and westwards along the precipitation gradient. Loadings of the first two rotated principal components separated the 16 forest sites into three major groups corresponding to the three regions affected by the East Asian Monsoon, Westerlies, and their interaction. Thus, spatial variability in tree growth is an excellent bioindicator of regional climate.

Metabarcoding of modern sedimentary DNA from the Tibetan Plateau and Siberia as a training dataset for vegetation reconstructions

2021 ◽  
Author(s):  
Weihan Jia ◽  
Kathleen Stoof-Leichsenring ◽  
Sisi Liu ◽  
Kai Li ◽  
Sichao Huang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Lake Sediments ◽  
Plant Diversity ◽  
Lake Water ◽  
Aquatic Plant ◽  
Freshwater Ecosystems ◽  
The Tibetan Plateau ◽  
Plant Dna ◽  
Continental Scale ◽  
Dna Metabarcoding

&lt;p&gt;Lake sedimentary DNA (&lt;em&gt;sed&lt;/em&gt;DNA) is an established tool to trace past changes in vegetation composition and plant diversity. However, little is known about the relationships between sedimentary plant DNA and modern vegetational and environmental conditions. In this study, we investigate i) the relationships between the preservation of sedimentary plant DNA and environmental variables, ii) the modern analogue of ancient plant DNA assemblages archived in lake sediments, and iii) the usability of sedimentary plant DNA for characterization of terrestrial and aquatic plant composition and diversity based on a large dataset of PCR-amplified plant DNA data retrieved from 259 lake surface sediments from the Tibetan Plateau and Siberia. Our results indicate the following: i) Lake-water electrical conductivity and pH are the most important variables for the preservation of plant DNA in lake sediments. We expect the best preservation conditions for sedimentary plant DNA in small deep lakes characterized by high water conductivities (&amp;#8805;100 &amp;#956;S cm&lt;sup&gt;-1&lt;/sup&gt;) and neutral to slightly alkaline pH conditions (7&amp;#8211;9). ii) Plant DNA metabarcoding is promising for palaeovegetation reconstruction in high mountain regions, where shifts in vegetation are solely captured by the &lt;em&gt;sed&lt;/em&gt;DNA-based analogue matching and fossil pollen generally has poor modern analogues. However, the biases in the representation of some taxa could lead to poor analogue conditions. iii) Plant DNA metabarcoding is a reliable proxy to reflect modern vegetation types and climate characteristics at a sub-continental scale. However, the resolution of the &lt;em&gt;trn&lt;/em&gt;L P6 loop marker, the incompleteness of the reference library, and the extent of &lt;em&gt;sed&lt;/em&gt;DNA preservation are still the main limitations of this method. iv) Plant DNA metabarcoding is a suitable proxy to recover modern aquatic plant diversity, which is mostly affected by July temperature and lake-water conductivity. Ongoing warming might decrease macrophyte richness in the Tibetan Plateau and Siberia, and ultimately threaten the health of these important freshwater ecosystems. To conclude, sedimentary plant DNA presents a high correlation with modern vegetation and may therefore be an important proxy for reconstruction of past vegetation.&lt;/p&gt;

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