Evaluation of the regional vegetation and climate in the Eastern Alps (Austria) during MIS 3–4 based on pollen analysis of the classical Baumkirchen paleolake sequence

2018 ◽  
Vol 90 (1) ◽  
pp. 153-163 ◽  
Author(s):  
Samuel Jonathan Barrett ◽  
Ruth Drescher-Schneider ◽  
Reinhard Starnberger ◽  
Christoph Spötl
Keyword(s):  
Pollen Analysis ◽  
Vegetation History ◽  
Research Effort ◽  
Eastern Alps ◽  
Glacial Cycle ◽  
Oxygen Isotope Stage ◽  
Last Glacial ◽  
Mis 3 ◽  
Quaternary Stratigraphy ◽  
History Of

AbstractThe pre-last glacial maximum paleolake sediments at Baumkirchen, western Austria, are well known in Alpine Quaternary stratigraphy as being the type locality of the Middle to Upper Würmian transition. Their location provides a rare opportunity to investigate the vegetation history of the interior of the Alps during the last glacial cycle. A recent renewed research effort involving new drilling revealed a 250-m-thick lacustrine sequence with an older, ca. Marine Oxygen Isotope Stage (MIS) 4 phase and a younger, mid- to late MIS 3 phase. Pollen analysis reveals generally poor preservation and very low pollen concentration due to very high sedimentation rates. On the basis of pollen percentages and influx rates, six pollen zones (PZ) were assigned. PZ1 and 2 correspond to the entire ca. MIS 4 section and are characterized by only scattered vegetation representing an extremely cold and dry climate. Two stadials and two interstadials were identified in the MIS 3 section. The interstadials are characterized by well-developed open vegetation with some stands of trees, with the upper PZ6 being better developed but still forest-free. On the basis of previous radiocarbon dating, this zone (PZ6) is correlated to Greenland Interstadial (GI) 7 and the lower interstadial (PZ4) tentatively to GI 8.

scholarly journals Quaternary Ice-Age dynamics in the Colombian Andes: developing an understanding of our legacy

2004 ◽  
Vol 359 (1442) ◽  
pp. 173-181 ◽  
Author(s):  
Henry Hooghiemstra ◽  
Thomas Van der Hammen
Keyword(s):  
Vegetation History ◽  
Floristic Composition ◽  
Ice Age ◽  
Forest Belt ◽  
Tropical Andes ◽  
Glacial Cycle ◽  
Altitudinal Distribution ◽  
Last Glacial ◽  
Colombian Andes ◽  
The Last Glacial

Pollen records from lacustrine sediments of deep basins in the Colombian Andes provide records of vegetation history, the development of the floristic composition of biomes, and climate variation with increasing temporal resolution. Local differences in the altitudinal distribution of present–day vegetation belts in four Colombian Cordilleras are presented. Operating mechanisms during Quaternary Ice–Age cycles that stimulated speciation are discussed by considering endemism in the asteraceous genera Espeletia , Espeletiopsis and Coespeletia . The floristically diverse lower montane forest belt (1000–2300 m) was compressed by ca . 55% during the last glacial maximum (LGM) (20 ka), and occupied the slopes between 800 m and 1400 m during that period. Under low LGM atmospheric p CO 2 values, C 4 –dominated vegetation, now occurring below 2200 m, expanded up to ca. 3500 m. Present–day C 3 –dominated paramo vegetation is therefore not an analogue for past C 4 –dominated vegetation (with abundant Sporobolus lasiophyllus ). Quercus immigrated into Colombia 478 ka and formed an extensive zonal forest from 330 ka when former Podocarpus –dominated forest was replaced by zonal forest with Quercus and Weinmannia . During the last glacial cycle the ecological tolerance of Quercus may have increased. In the ecotone forests Quercus was rapidly and massively replaced by Polylepis between 45 and 30 ka illustrating complex forest dynamics in the tropical Andes.

Vegetation history of Western Russia (Upper Dnieper, Smolensk region): Climate and human impact on landscape in last two millennia

2020 ◽  
Author(s):  
Nikita Lavrenov ◽  
Ekaterina Ershova ◽  
Margarita Zhuravkova ◽  
Nikolay Krenke
Keyword(s):  
Human Impact ◽  
Pollen Analysis ◽  
Vegetation History ◽  
Taxonomic Diversity ◽  
Analysis Data ◽  
History Of Vegetation ◽  
Modern Analogue ◽  
First Results ◽  
History Of ◽  
Indigenous Forest

<p>Climate and vegetation history of Upper Dnieper region (Western Russia) is investigated poorly while archaeological studies provide evidences of human activities during last 3 millennia. Our study presents vegetation reconstruction based on pollen analysis of sediments extracted from two sites in Smolensk region. The first site is located in Katynka river bassin and pollen analysis of extracted buried soil, alluvium and peat sediments demonstrates vegetation dynamics in archaeologically rich area over 5 millennia. The second site is located in 50 km from to the west from Smolensk and in 15 km to east from the Russian-Belarus state border. The analysis of extracted peat sediments presents regional history of vegetation. The aim of our study is to compare data obtained from both sites and to estimate climate and human influence on vegetation during last two millennia when activities associated with agriculture changed Dnieper valley landscape significantly.</p><p>The first results of pollen analysis data of the first site allow to register significant human impact on vegetation 2.0-0.8 ka BP. Before that period pollen of indigenous forest trees dominates in spectra while since 2.0 ka BP pollen compassion changes dramatically and pollen of <em>Betula</em> and <em>Pinus</em> is in majority in so-called “Gnezdovo soil” lay. Medieval lays of sapropel contains mostly pollen of <em>Pinus</em> with admixture of <em>Betula</em> and <em>Alnus</em>. Taxonomic diversity and presence of meadow herbs, weeds and cultivated taxa pollen increases significantly (up to 30%). Dynamics of pollen composition in specimens from the second site allows us to register slow processes of indigenous vegetation recovery over last 3 centuries approximately. Modern analogue technique applied on pollen data and analysis of historical data makes possible to separate impacts of climate and human on vegetation of the past and to reconstruct the climate of last two millennia.</p><p>The study was funded by RFBR, project number 19-34-90172.</p><p><br><br></p>

scholarly journals Vegetation History of the Southern Tohoku District, Based on Pollen Analysis of Aranuma in the Shirataka Lakes, Yamagata Prefecture.

2002 ◽  
Vol 41 (5) ◽  
pp. 375-387 ◽  
Author(s):  
Yoshimune Morita ◽  
Hiroshi Yagi ◽  
Takashi Inokuchi ◽  
Tomoko Yamazaki
Keyword(s):  
Pollen Analysis ◽  
Vegetation History ◽  
History Of

Millennial-scale variations in western Sierra Nevada precipitation during the last glacial cycle MIS 4/3 transition

2014 ◽  
Vol 82 (1) ◽  
pp. 236-248 ◽  
Author(s):  
Jessica L. Oster ◽  
Isabel P. Montañez ◽  
Regina Mertz-Kraus ◽  
Warren D. Sharp ◽  
Greg M. Stock ◽  
...  
Keyword(s):  
North America ◽  
Sierra Nevada ◽  
Western Slope ◽  
Western North America ◽  
Glacial Cycle ◽  
Climatic Response ◽  
Last Glacial ◽  
Mis 3 ◽  
Heinrich Event ◽  
The Last Glacial

AbstractDansgaard–Oeschger (D–O) cycles had far-reaching effects on Northern Hemisphere and tropical climate systems during the last glacial period, yet the climatic response to D–O cycles in western North America is controversial, especially prior to 55 ka. We document changes in precipitation along the western slope of the central Sierra Nevada during early Marine Oxygen Isotope Stages (MIS) 3 and 4 (55–67 ka) from a U-series dated speleothem record from McLean's Cave. The timing of our multi-proxy geochemical dataset is coeval with D–O interstadials (15–18) and stadials, including Heinrich Event 6. The McLean's Cave stalagmite indicates warmer and drier conditions during Greenland interstadials (GISs 15–18), signified by elevated δ18O, δ13C, reflectance, and trace element concentrations, and less radiogenic 87Sr/86Sr. Our record extends evidence of a strong linkage between high-latitude warming and reduced precipitation in western North America to early MIS 3 and MIS 4. This record shows that the linkage persists in diverse global climate states, and documents the nature of the climatic response in central California to Heinrich Event 6.

scholarly journals Last Glacial climate reconstruction by exploring glacier sensitivity to climate on the southeastern slope of the western Nyaiqentanglha Shan, Tibetan Plateau

2017 ◽  
Vol 63 (238) ◽  
pp. 361-371 ◽  
Author(s):  
XIANGKE XU ◽  
BAOLIN PAN ◽  
GUOCHENG DONG ◽  
CHAOLU YI ◽  
NEIL F. GLASSER
Keyword(s):  
Tibetan Plateau ◽  
Regional Climate ◽  
The Tibetan Plateau ◽  
Glacial Cycle ◽  
Geological Evidence ◽  
Oxygen Isotope Stage ◽  
Last Glacial ◽  
Mountain Glaciers ◽  
The Last Glacial Maximum ◽  
The Last Glacial

ABSTRACTImprovements in understanding glacial extents and chronologies for the southeastern slope of the western Nyaiqentanglha Shan on the Tibetan Plateau are required to understand regional climate changes during the Last Glacial cycle. A two-dimensional numerical model of mass balance, based on snow–ice melting factors, and of ice flow for mountain glaciers is used to assess the glacier sensitivity to climatic change in a catchment of the region. The model can reproduce valley glaciers, wide-tongued glaciers and a coalescing glacier within step temperature lowering and precipitation increasing experiments. The model sensitivity experiments also indicate that the dependence of glacier growth on temperature and/or precipitation is nonlinear. The model results suggest that the valley glaciers respond more sensitively to an imposed climate change than wide-tongued and coalescing glaciers. Guided by field geological evidence of former glacier extent and other independent paleoclimate reconstructions, the model is also used to constrain the most realistic multi-year mean temperatures to be 2.9–4.6°C and 1.8–2.5°C lower than present in the glacial stages of the Last Glacial Maximum and middle marine oxygen isotope stage 3, respectively.

scholarly journals Southwest Greenland shelf glaciation during MIS 4 more extensive than during the Last Glacial Maximum

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Marit-Solveig Seidenkrantz ◽  
Antoon Kuijpers ◽  
Jesper Olsen ◽  
Christof Pearce ◽  
Sofia Lindblom ◽  
...  
Keyword(s):  
Sea Water ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Glacial Cycle ◽  
Oxygen Isotope Stage ◽  
Last Glacial ◽  
Irminger Sea ◽  
West Greenland Current ◽  
Glacial Advance ◽  
The Last Glacial

Abstract Although geological and modelling evidence indicate that the last glacial inception in North America was in NE Canada, little is known about the glacial response of the nearby western Greenland Ice Sheet (GIS) during the glacial advance of marine oxygen isotope stage 4 (MIS4). Our multi-proxy study of a marine sediment core collected about 60 km southwest of the Outer Hellefisk Moraines demonstrates that in the southern Davis Strait region the most extreme Greenland shelf glaciation of the last glacial cycle occurred during MIS 4, with another prominent glacial advance at 37–33 kyr BP. During those periods the GIS likely reached the Outer Hellefisk Moraines in this area. Except for these two periods, our data suggest significant advection of relatively warm Irminger Sea Water by the West Greenland Current since MIS 4. This advection likely limited the extent of the MIS2 glaciation on the SW Greenland shelf. Decreased precipitation over southwestern Greenland predicted by atmospheric models as a downstream effect of a much larger MIS2 Laurentide Ice Sheet may have played an additional role.

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