Research Article

Vegetation changes in the Neotropical Gran Sabana (Venezuela) around the Younger Dryas chron

  1. Encarni Montoya1,2,*,
  2. Valenti Rull1,
  3. Nathan D. Stansell3,
  4. Broxton W. Bird3,
  5. Sandra Nogué1,4,
  6. Teresa Vegas-vilarrúbia5,
  7. Mark B. Abbott6,
  8. Wilmer A. Díaz7

Article first published online: 9 FEB 2011

DOI: 10.1002/jqs.1445

Issue

Journal of Quaternary Science

Journal of Quaternary Science

Volume 26, Issue 2, pages 207–218, February 2011

Additional Information

How to Cite

Montoya, E., Rull, V., Stansell, N. D., Bird, B. W., Nogué, S., Vegas-vilarrúbia, T., Abbott, M. B. and Díaz, W. A. (2011), Vegetation changes in the Neotropical Gran Sabana (Venezuela) around the Younger Dryas chron. J. Quaternary Sci., 26: 207–218. doi: 10.1002/jqs.1445

Author Information

  1. 1

    Palynology and Palaeoecology Lab, Botanical Institute of Barcelona, Barcelona, Spain

  2. 2

    Department of Animal Biology, Plant Biology and Ecology, Autonomous University of Barcelona, Campus Bellaterra, 08193 Barcelona, Spain

  3. 3

    Byrd Polar Research Center, The Ohio State University, Columbus, OH, USA

  4. 4

    Oxford Long Term Ecology Lab, Biodiversity Institute, Department of Zoology, South Parks Road, Oxford, UK

  5. 5

    Department of Ecology, University of Barcelona, Barcelona, Spain

  6. 6

    Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, PA, USA

  7. 7

    CIEG – UNEG, Puerto Ordaz, estado Bolivar, Venezuela

*Department of Animal Biology, Plant Biology and Ecology, Autonomous University of Barcelona, Campus Bellaterra, 08193 Barcelona, Spain.

Publication History

  1. Issue published online: 24 FEB 2011
  2. Article first published online: 9 FEB 2011
  3. Manuscript Accepted: 28 JUL 2010
  4. Manuscript Revised: 27 JUL 2010
  5. Manuscript Received: 8 FEB 2010

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Keywords:

  • Fire;
  • Late Glacial;
  • Neotropics;
  • vegetation change;
  • Younger Dryas

Abstract

The occurrence of the Younger Dryas cold reversal in northern South America midlands and lowlands remains controversial. We present a palaeoecological analysis of a Late Glacial lacustrine section from a midland lake (Lake Chonita, 4.6501 °N, 61.0157 °W, 884 m elevation) located in the Venezuelan Gran Sabana, based on physical and biological proxies. The sediments were mostly barren from ∼15.3 to 12.7 k cal a BP, probably due to poor preservation. A ligneous community with no clear modern analogues was dominant from 12.7 to 11.7 k cal a BP (Younger Dryas chronozone). At present, similar shrublands are situated around 200 m elevation above the lake, suggesting a cooling-driven downward shift in vegetation during that period. The interval from 11.7 to 10.6 k cal a BP is marked by a dramatic replacement of the shrubland by savannas and a conspicuous increase in fire incidence. The intensification of local and regional fires at this interval could have played a role in the vegetation shift. A change to wetter, and probably warmer, conditions is deduced after 11.7 k cal a BP, coinciding with the early Holocene warming. These results support the hypothesis of a mixed origin (climate and fire) of the Gran Sabana savannas, and highlight the climatic instability of the Neotropics during the Late Glacial. Copyright © 2011 John Wiley & Sons, Ltd.

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