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| Titel |
Pollen, sediment and diatom response to past climate and environmental change in the Balkan region: the Holocene record of Lake Dojran (Greece/FYROM) |
| VerfasserIn |
Alessia Masi, Laura Sadori, Alexander Francke, Caterina Pepe, Bernd Wagner |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250101545
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| Publikation (Nr.) |
 EGU/EGU2015-705.pdf |
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| Zusammenfassung |
| Lake Dojran (41Ë 12’N, 22Ë 44’E, 144 m a.s.l.) is located at the border between the F.Y.R. of
Macedonia and Greece in a karstic basin formed by a combination of Tertiary volcanic and
tectonic activities. The lake is fed by small rivers, creeks and springs, with most of the run
off originating from the near Belasica and Kroussia Mountains. The area of Lake
Dojran is influenced by the mountain climate of the central and northern Balkans. In
addition, it is tempered by the influence of the Mediterranean Sea, to which it is
exposed via the Thessaloniki Plain. The marine influence provides mild winters with
high precipitation and long, hot, dry summers. The diverse natural vegetation has
been heavily influenced by human activities, particularly during the historical era.
Remnants of natural vegetation which survive are dominated by mesophilous plants, in
particular deciduous oaks and ashes together with riparian elements such as alders and
planes.
A 717 cm core was collected from the deepest part of the lake (ca. 6.6 m depth), in
Macedonian waters. Thirteen radiocarbon dates carried out on terrestrial plant remains,
charcoal, carbonate shell fragments, and bulk organic matter, established that the core covers
the last ca. 12500 years, spanning the Younger Dryas to the present (1). Here, we build on
previous sedimentological and diatom-based palaeolimnological research, strengthening the
multi-proxy dataset by addition of palynological evidence for vegetation catchment
change.
The Late Glacial was characterized first by an Artemisia steppe, followed by expansion of
chenopods and then grasses, confirming the arid climate inferred from sedimentology and
diatom data. The subsequent expansion of grasses matches with an increase in lake level
inferred from changes in the diatom assemblages. Forest expansion at the onset of the
Holocene is characterized by deciduous, semideciduous and evergreen oaks, with
pine and fir, during an initial deepwater phase followed by shallowing towards
the mid Holocene. Intensification of erosion after 2800 cal yr BP inferred from
sedimentology (1) correlates clearly with palynological evidence for deforestation and
the intensification of cultivation of cereals and fruit trees such as Olea, Juglans
and Castanea. The palynological data also support diatom-based inferences that
Late Holocene environmental change also incorporates a climatic shift towards
aridification.
(1) Francke A., Wagner B., Leng M. J., Rethemeyer J., 2013. Clim Past 9: 481-498.
(2) Zhang X., Reed J., Wagner B., Francke A., Levkov Z., 2014. Quat Sci Rev 103: 51-66. |
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