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- Sommer, Robert S., et al.
(författare)
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Holocene recolonization and extinction of the pond turtle, Emys orbicularis (L., 1758), in Europe
- 2007
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Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791. ; 26:25-28, s. 3099-3107
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Tidskriftsartikel (refereegranskat)abstract
- We reconstruct the Holocene range fluctuations of the European pond turtle (Emys orbicularis) for northern and Central Europe. Based on 529 subfossil records and radiocarbon dating of critical finds, we provide evidence that E. orbicularis experienced a rapid range expansion with Holocene warming. Phylogeographic data argue for a colonization of northern and Central Europe from a glacial refuge located in the south-eastern Balkans. Already in the Late Preboreal (9100-8600 cal BC) the species occurred in northern Central Europe and was widespread in Denmark and southern Sweden (Skane) during the Boreal (8600-7100 cal BC). The maximum range extension occurred during the Holocene climatic optimum (Atlantic: 7100-3750 cal BC), with records in southern England, middle Sweden, and northern Estonia. After the early Subboreal (3750-1750 cal BC) northern populations collapsed, coinciding with a climatic cooling and oceanization. Northern populations were most likely established via long distance dispersal (rafting using rivers debouching in the North and Baltic Seas); after northern Europe was reached, a minimum dispersal of 50 km per 100 years may be hypothesized for the Boreal. (c) 2007 Elsevier Ltd. All rights reserved.
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| 2. |
- Sommer, Robert S., et al.
(författare)
-
Unexpected early extinction of the European pond turtle (Emys orbicularis) in Sweden and climatic impact on its Holocene range
- 2009
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Ingår i: Molecular Ecology. - 0962-1083. ; 18:6, s. 1252-1262
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Tidskriftsartikel (refereegranskat)abstract
- Using ancient DNA sequences of subfossil European pond turtles (Emys orbicularis) from Britain, Central and North Europe and accelerator mass spectrometry radiocarbon dating for turtle remains from most Swedish sites, we provide evidence for a Holocene range expansion of the pond turtle from the southeastern Balkans into Britain, Central Europe and Scandinavia, according to the 'grasshopper pattern' of Hewitt. Northeastern Europe and adjacent Asia were colonized from another refuge located further east. With increasing annual mean temperatures, pond turtles reached southern Sweden approximately 9800 years ago. Until approximately 5500 years ago, rising temperatures facilitated a further range expansion up to ostergotland, Sweden (approximately 58 degrees 30'N). However, around 5500 years ago pond turtle records suddenly terminate in Sweden, some 1500 years before the Holocene thermal maximum ended in Scandinavia and distinctly earlier than previously thought. This extinction coincides with a temporary cooling oscillation during the Holocene thermal maximum and is likely related to lower summer temperatures deteriorating reproductive success. Although climatic conditions improved later again, recolonization of Sweden from southern source populations was prevented by the Holocene submergence of the previous land connection via the Danish Straits that occurred approximately 8500 years ago.
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