DATE2016-05-25 13:29:03
IDABSTRACT20160525132903-1015
CONTACTwagnerb@uni-koeln.de
PRESENTATIONORAL-PLENARY
INVITED0
IDSESSION3
TITLEINTEGRATING GEOLOGICAL AND BIOLOGICAL INFORMATION ON THE AGE, THE ORIGIN, THE ENVIRONMENTAL HISTORY, THE BIODIVERSITY, AND THE ENDEMISM IN LAKE OHRID (FYROM/ALBANIA): INTERIM RESULTS FROM THE SCOPSCO PROJECT
AUTHORSBernd Wagner (1), Thomas Wilke (2), Alexander Francke (1), Sebastian Krastel (3), Niklas Leicher (1), Janna Just (1), Giovanni Zanchetta (8), Laura Sadori (4), Thomas Wonik (5), Hendrik Vogel (7), Melanie Leng (6)
AFFILIATIONS
  1. Institute Of Geology And Mineralogy, University Of Cologne Cologne (Germany)
  2. Department Of Animal Ecology & Systematics, Justus Liebig University Giessen Giessen (Germany)
  3. Institute Of Geosciences, Christian-albrechts-universität Zu Kiel Kiel (Germany)
  4. Dipartimento Di Biologia Ambientale, Università Di Roma Rome (Italy)
  5. Leibniz Institute For Applied Geophysics Hannover (Germany)
  6. Centre For Environmental Geochemistry, School Of Geography, University Of Nottingham Nottingham (United Kingdom)
  7. Institute Of Geological Sciences & Oeschger Centre For Climate Change Research, University Of Bern Bern (Switzerland)
  8. Dipartimento Di Scienze Della Terra, University Of Pisa Pisa (Italy)
ABSTRACTWe review and synthesise the existing information on (i) the age and origin of Lake Ohrid (Former Yugoslavian Republic of Macedonia/Albania), (ii) its regional seismotectonic history, (iii) the volcanic activity and climate change in the central northern Mediterranean region, and (iv) the triggers of biodiversity and endemism and thus provides a comprehensive state of the art overview to the four main aims defined in the Scientific Collaboration of Past Speciation Conditions in Lake Ohrid (SCOPSCO) project. According to the existing data, the Lake Ohrid basin formed by transtension during the Miocene and opened later, between the Pliocene and the Pleistocene. Lake Ohrid established de novo in the still relatively narrow valley between 2.0 and 1.3 Myr ago. The entire lake history is recorded in a 569 m long sediment sequence, which was recovered under the umbrella of the International Continental Scientific Drilling Program (ICDP) from the DEEP site in the central part of the lake in April 2013. So far, 53 tephra and cryptotephra horizons were found in the upper 460 m of this sequence. Ten of these tephras and one cryptotephra were used by means of tephrostratigraphy and tephrochronology as 1st order tie points to establish an age depth model for the uppermost 247.8 m of the sediment succession. The age model was complemented by 2nd order tie points from tuning of biogeochemical proxy data to orbital parameters and revealed that the upper 247.8 m cover the last 637 kyr. The multi-proxy dataset indicates long-term variability, such as glacial/interglacial changes, and short-term environmental change, caused for example by tephra deposition or Heinrich events. Over longer time scales, Lake Ohrid does not seem to have functioned as a refugium or dispersal origin for freshwater biota. This is different from the Lake Ohrid surrounding, where the mountainous settings provided a refugium for vegetation during the relatively cold and dry glacial periods. Although Lake Ohrid experienced severe environmental change over the last 637 kyr, biological studies indicate that there are no extinction events over this period. The lack of severe catastrophic events, along with constant diversification rates, high ecosystem resilience, lake internal dispersal limitation, and high buffer capacity of the water body, are proposed to be the main drivers for the extraordinary high endemic biodiversity of Lake Ohrid.
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