High resolution climate signals in the Late Glacial as reflected in European tree-ring chronologies
by
Michael Friedrich
Hohenheim University, Institute of Botany (210), D-70593 Stuttgart, Germany
Coauthors: Bernd Kromer (Heidelberg Academy of Sciences/ University of Heidelberg), Klaus F. Kaiser (WSL Birmensdorf/ University of Zurich), Marco Spurk (Heidelberg Academy of Sciences/ Hohenheim University)

Late Glacial and Holocene tree-ring chronologies are unique archives, which provide various information of past environment on a true annual time scale. Changes in ring-width can be related to past climate anomalies and dendrodated wood provides an ideal source for radiocarbon calibration. In Hohenheim we constructed tree-ring width chronologies from a large number of well preserved subfossil oaks (Quercus robur, Q. petraea) and pines (Pinus sylvestris) found in Quaternary deposits of the large rivers in Central Europe. The oak and pine chronologies could be combined to an uninterrupted tree-ring chronology, which reaches now 12.014 years back to 11.919 BP, covering the full length of the Holocene and the final centuries of the Younger Dryas. In this contribution we present new floating tree-ring chronologies from the Late Glacial, built from subfossil Scots pines (Pinus sylvestris) grown in several regions of Central and Southern Europe. It combines pines from various sites in Eastern Germany, Northern Germany, Southern Germany, Northern Switzerland and Northern Italy. The chronologies cover 1500 years between 12.300 ¹⁴C B.P. and 10.900 ¹⁴C B.P. (chronozones of Bølling-Older Dryas-Allerød / Greenland Interstadial 1) and major parts of the Younger Dryas. Through a series of decadal high precision radiocarbon measurements we obtained floating radiocarbon chronologies, which allow absolute dating by accurate wiggle-matching to the INTCAL98 calibration curve. The trees from the Bølling-Allerød-Interstadial show a surprisingly coherent pattern in ring-width variations all over Central Europe and Northern Italy, indicating a strong external climatic factor. We identified major growth events in the ring widths, i.e. the Older Dryas Stadial, which appears synchronous to events seen in isotopic and tracer signals in the Greenland ice cores and to changes in the strength of the trade wind forced upwelling seen in the varves of the Cariaco Basin of the tropical North Atlantic off Venezuela. Therefore these events seem to be at least of hemispheric extent.

Date received: March 30, 2001

Copyright © 2001 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cagc-84.