Abrupt climate and vegetation variability of eastern Anatolia during the last glacial
Detailed analyses of the Lake Van pollen, Ca / K ratio, and stable oxygen isotope record allow the identification of millennial-scale vegetation and environmental changes in eastern Anatolia throughout the last glacial (~ 111.5–11.7 ka BP). The climate of the last glacial was cold and dry, indicated...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-11-01
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| Series: | Climate of the Past |
| Online Access: | http://www.clim-past.net/11/1491/2015/cp-11-1491-2015.pdf |
| Summary: | Detailed analyses of the Lake Van pollen, Ca / K ratio, and stable oxygen
isotope record allow the identification of millennial-scale vegetation and
environmental changes in eastern Anatolia throughout the last glacial
(~ 111.5–11.7 ka BP). The climate of the last glacial was cold and
dry, indicated by low arboreal pollen (AP) levels. The driest and coldest
period corresponds to Marine Isotope Stage (MIS) 2
(~ 28–14.5 ka BP), which was dominated by highest values of
xerophytic steppe vegetation.
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Our high-resolution multi-proxy record shows rapid expansions and
contractions of tree populations that reflect variability in temperature and
moisture availability. These rapid vegetation and environmental changes can
be related to the stadial-interstadial pattern of Dansgaard–Oeschger (DO)
events as recorded in the Greenland ice cores. Periods of reduced moisture
availability were characterized by enhanced occurrence of xerophytic species
and high terrigenous input from the Lake Van catchment area. Furthermore, the
comparison with the marine realm reveals that the complex atmosphere–ocean
interaction can be explained by the strength and position of the westerlies,
which are responsible for the supply of humidity in eastern Anatolia.
Influenced by the diverse topography of the Lake Van catchment, more
pronounced DO interstadials (e.g., DO 19, 17–16, 14, 12 and 8) show the
strongest expansion of temperate species within the last glacial. However,
Heinrich events (HE), characterized by highest concentrations of ice-rafted
debris (IRD) in marine sediments, cannot be separated from other DO stadials
based on the vegetation composition in eastern Anatolia. In addition, this
work is a first attempt to establish a continuous microscopic charcoal record
for the last glacial in the Near East. It documents an immediate response to
millennial-scale climate and environmental variability and enables us to shed
light on the history of fire activity during the last glacial. |
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| ISSN: | 1814-9324 1814-9332 |