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DOI	10.1016/j.quascirev.2020.106333
	Impact of climatic extremes on Alpine ecosystems during MIS 3
	Stojakowits P.; Mayr C.; Lücke A.; Wissel H.; Hedenäs L.; Lempe B.; Friedmann A.; Diersche V.
发表日期	2020
ISSN	0277-3791
卷号	239
英文摘要	The effects of climatic extremes on Alpine ecosystems, such as in the last glacial period, are poorly understood. The recently discovered Nesseltalgraben site is currently the best dated and most complete high-resolution sedimentary sequence in the northern Alps covering the Marine Isotope Stage (MIS) 3 around 59-28 calibrated kiloyears before present (ka cal BP). The MIS 3 is a period with frequent climatic fluctuations known as Dansgaard-Oeschger cycles or Greenland interstadials-stadials. Here, we present pollen assemblages, bryophyte macrofossils, and stable isotopes (δ2H, δ13C, δ18O) from the Nesseltalgraben to elucidate palaeoenvironments and palaeoclimatic variability during that period. In addition to bulk sedimentary cellulose, also cellulose extracted from fossil wood, monocots, and bryophytes was analysed isotopically. Among the terrestrial pollen, Poaceae and arboreal pollen show an antithetic behaviour reflecting interstadial-stadial variations. Arboreal pollen are dominated by Pinus sylvestris-type, with admixtures of Picea, Betula, Alnus, and Salix. The arboreal pollen record exhibits several maxima indicating milder climatic conditions tentatively assigned to Greenland interstadials 17–14, 12/11, 8, and 6. During Heinrich events 5 and 4, the arboreal pollen record shows distinct minima underlining a severe impact of these events on regional climate and vegetation. Bryophyte assemblages show predominant wetland conditions at the site during the entire MIS 3. The sudden occurrence of the bryophyte Drepanocladus turgescens after 31.6 ka cal BP indicates a change from a fen to a frequently drying wetland environment. This habitat change is presumably linked to enhanced glaciofluvial action caused by glaciers approaching the site. Carbon, hydrogen, and oxygen stable isotope records of bulk sedimentary cellulose exhibit comparably stable conditions from 59 until 52 ka cal BP and increased values around 51 ka cal BP followed by a period of almost absent cellulose until 39 ka cal BP. Thereafter, and lasting until 30 ka cal BP, bulk sedimentary cellulose isotope records (δ2H, δ13C, and δ18O) reveal strongly fluctuating values. These isotope variations are interpreted as variable mixtures between terrestrial lignified plants and monocots on the one, and wetland bryophyte sources on the other hand. A strong negative isotope excursion in the bulk sedimentary and the bryophyte cellulose records around 36.4 ka cal BP is contemporaneous with maximum Cyperaceae pollen and best explained by progressively waterlogged soils due to permafrost. The rise in the bryophyte δ18O record thereafter, accompanied by likewise increasing δ13C values, most likely indicates an enhanced evaporation of source waters. © 2020 Elsevier Ltd
英文关键词	Bryophytes; Cellulose; Dansgaard-Oeschger events; Greenland interstadials; Heinrich events; Nesseltalgraben; Northern Alps; Pollen; Stable isotopes; Vegetation dynamics
语种	英语
scopus关键词	Cellulose; Climatology; Ecosystems; Isotopes; Permafrost; Sedimentology; Wetlands; Wood; Climatic conditions; Climatic fluctuations; Dansgaard-Oeschger cycles; Last glacial period; Marine isotope stages; Oxygen stable isotopes; Sedimentary sequence; Wetland environment; Plants (botany); alpine environment; bryophyte; cellulose; fen; isotopic analysis; permafrost; regional climate; sedimentary sequence; stable isotope; Cellulose; Ecosystems; Isotopes; Meteorology; Permafrost; Wetlands; Arctic; Greenland; Alnus; Betula; bryophytes; Cyperaceae; Drepanocladus; Liliopsida; Picea; Pinus sylvestris; Poaceae; Salix
来源期刊	Quaternary Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151450
作者单位	Universität Augsburg, Institute of Geography, Alter Postweg 118, Augsburg, 86135, Germany; Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Geography, Wetterkreuz 15, Erlangen, 91058, Germany; Ludwig-Maximilians-Universität München, Department of Earth and Environmental Sciences, Palaeontology and Geobiology, Richard-Wagner-Str. 10, München, 80333, Germany; Ludwig-Maximilians-Universität München, GeoBio-Center, Richard-Wagner-Str. 10, München, 80333, Germany; Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, IBG-3: Agrosphere, Jülich, 52425, Germany; Swedish Museum of Natural History, Department of Botany, Box 50007, Stockholm, SE-104 05, Sweden; Technical University of Munich, Chair of Engineering Geology, Arcisstraße 21, München, 80333, Germany; Schiller-Allee 1, Bayerisch, Gmain, 83457, Germany
推荐引用方式 GB/T 7714	Stojakowits P.,Mayr C.,Lücke A.,et al. Impact of climatic extremes on Alpine ecosystems during MIS 3[J],2020,239.
APA	Stojakowits P..,Mayr C..,Lücke A..,Wissel H..,Hedenäs L..,...&Diersche V..(2020).Impact of climatic extremes on Alpine ecosystems during MIS 3.Quaternary Science Reviews,239.
MLA	Stojakowits P.,et al."Impact of climatic extremes on Alpine ecosystems during MIS 3".Quaternary Science Reviews 239(2020).