title: Mean annual temperatures of mid-latitude regions derived from δ2H values of wood lignin methoxyl groups and its implications for paleoclimate studies.
abstract: Tree-rings are widely used climate archives providing annual resolutions on centennial to millennial timescales. Stable isotope ratios of tree-rings have been applied to assist with the delineation of climate parameters such as temperature and precipitation. Here, we investigated stable hydrogen isotope ratios (expressed as δ2H values) of lignin methoxyl groups of wood from various tree species collected along a ~3500km north-south transect across Europe with mean annual temperatures (MAT) ranging from -4 to +17°C. We found a strong linear relationship between MATs and δ2H values of wood lignin methoxyl groups. We used this relationship to predict MATs from randomly collected wood samples and found general agreement between predicted and observed MATs for the mid-latitudes on a global scale. Our results are discussed in context of their paleoclimate relevance and suggest that δ2H values of lignin methoxyl groups might have the potential to reconstruct MATs when applied on mid-latitudinal tree-ring chronologies of the Late Holocene.
authors.affiliation: Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234-236, D-69120 Heidelberg, Germany. Electronic address: tobias.anhaeuser@geow.uni-heidelberg.de.
authors.forename: Tobias
authors.initials: T
authors.lastname: Anhäuser
authors.affiliation: Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234-236, D-69120 Heidelberg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Greule
authors.affiliation: Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234-236, D-69120 Heidelberg, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Polag
authors.affiliation: Department of Geology and Geophysics, Global Change and Sustainability Center, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Gabriel J
authors.initials: GJ
authors.lastname: Bowen
authors.affiliation: Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234-236, D-69120 Heidelberg, Germany; Heidelberg Center for the Environment (HCE), Heidelberg University, D-69120 Heidelberg, Germany; Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, D-55128 Mainz, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Keppler
keywords: 2H/1H ratio; Apparent fractionation; Error source evaluation; Paleotemperature proxy; Tree source water