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| Titel |
Deglacial and Holocene vegetation and climatic changes in the southern Central Mediterranean from a direct land–sea correlation |
| VerfasserIn |
S. Desprat, N. Combourieu-Nebout, L. Essallami, M. A. Sicre, I. Dormoy, O. Peyron, G. Siani, V. Bout Roumazeilles, J. L. Turon |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 9, no. 2 ; Nr. 9, no. 2 (2013-03-20), S.767-787 |
| Datensatznummer |
250018019
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| Publikation (Nr.) |
 copernicus.org/cp-9-767-2013.pdf |
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| Zusammenfassung |
Despite a large number of studies, the long-term and millennial to
centennial-scale climatic variability in the Mediterranean region during the
last deglaciation and the Holocene is still debated, including in the
southern Central Mediterranean. In this paper, we present a new marine
pollen sequence (core MD04-2797CQ) from the Siculo-Tunisian Strait
documenting the regional vegetation and climatic changes in the southern
Central Mediterranean during the last deglaciation and the Holocene.
The MD04-2797CQ marine pollen sequence shows that semi-desert plants
dominated the vegetal cover in the southern Central Mediterranean between
18.2 and 12.3 ka cal BP, indicating prevailing dry conditions during the
deglaciation, even during the Greenland Interstadial (GI)-1. Across the
transition Greenland Stadial (GS)-1 – Holocene, Asteraceae-Poaceae steppe
became dominant till 10.1 ka cal BP. This record underlines with no
chronological ambiguity that even though temperatures increased, deficiency
in moisture availability persisted into the early Holocene. Temperate trees
and shrubs with heath underbrush or maquis expanded between 10.1 and 6.6 ka,
corresponding to Sapropel 1 (S1) interval, while Mediterranean plants only
developed from 6.6 ka onwards. These changes in vegetal cover show that the
regional climate in southern Central Mediterranean was wetter during S1 and
became drier during the mid- to late Holocene. Wetter conditions during S1
were likely due to increased winter precipitation while summers remained
dry. We suggest, in agreement with published modeling experiments, that the
early Holocene increased melting of the Laurentide Ice Sheet in conjunction
with weak winter insolation played a major role in the development of winter
precipitation maxima in the Mediterranean region in controlling the strength
and position of the North Atlantic storm track.
Finally, our data provide evidence for centennial-scale vegetation and
climatic changes in the southern Central Mediterranean. During the wet early
Holocene, alkenone-derived cooling episodes are synchronous with herbaceous
composition changes that indicate muted changes in precipitation. In
contrast, enhanced aridity episodes, as detected by strong reduction in
trees and shrubs, are recorded during the mid- to late Holocene. We show
that the impact of the Holocene cooling events on the Mediterranean
hydroclimate depend on baseline climate states, i.e. insolation and ice
sheet extent, shaping the response of the mid-latitude atmospheric
circulation. |
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