Vegetation changes in the Neotropical Gran Sabana (Venezuela) around the Younger Dryas chron
Article first published online: 9 FEB 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Journal of Quaternary Science
Volume 26, Issue 2, pages 207–218, February 2011
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
- Issue published online: 24 FEB 2011
- Article first published online: 9 FEB 2011
- Manuscript Accepted: 28 JUL 2010
- Manuscript Revised: 27 JUL 2010
- Manuscript Received: 8 FEB 2010
- Late Glacial;
- vegetation change;
- Younger Dryas
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.