Lake Van in eastern Turkey is considered a unique climate archive.
Lake Van in eastern Turkey is considered a unique climate archive. Several years ago, an international team of scientists led by the University of Bonn raised sediments from the bottom of the lake reflecting the past 600,000 years. An interdisciplinary group of soil scientists and paleobotanists from the University of Bonn has now evaluated the drill cores for residues of early fires - with surprising findings. The fires did not mainly occur during particularly dry periods as assumed, but in comparatively humid and warm periods - because then the forests grew particularly lush and provided fuel for fires. The results are now published in the journal “Quaternary Science Reviews”.
Every summer there are more and more reports of bush and forest fires in the south. But even long before man adapted earth’s vegetation to his purposes or started fires, large fires occurred at regular intervals. Researchers at the University of Bonn have investigated the frequency and intensity of these steppe, bush and forest fires over the past 600,000 years using drill cores from the bottom of Lake Van in eastern Turkey. During this period, rainfall washed the soil and pollen from the surrounding area into the lake, which thus became a unique archive.
In 2010, an international team of scientists led by the paleobotanist Prof. Dr. Thomas Litt from the Institute of Geosciences and Meteorology had already drilled the deposits of Lake Van with a floating platform. “In the 220-meter thick sediment profile, we were able to reconstruct the vegetation of the past 600,000 years using pollen,” says Litt. On the basis of the composition of the pollen in the individual layers, the paleobotanist determined which plants grew particularly frequently during particular epochs. Based on the temperature and water requirements of these plant species, the scientists were able to draw conclusions about the respective climate.
Read more at University of Bonn
Image: From the Institute of Crop Science and Resource Conservation (INRES) at the University of Bonn with an extract of fire residues. (Credit: (c) Photo: Volker Lannert/Uni Bonn)
