Original Research ARTICLE
European Forest Cover During the Past 12 000 Years: A Palynological Reconstruction Based on Modern Analogues and Remote Sensing
- 1Institute of Pre- and Protohistoric Archaeology, Christian-Albrechts-Universität zu Kiel, Germany
- 2Christian-Albrechts-Universität zu Kiel, Germany
- 3Institute of Earth Surface Dynamics, University of Lausanne, Switzerland
- 4Department of Physical Geography and Ecosystem Science, Lund University, Sweden
- 5GEODE, UMR-CNRS 5602, Université Toulouse Jean Jaurès, France
- 6Research Group for Terrestrial Palaeoclimates, Max Planck Institute for Chemistry (MPG), Germany
- 7Department of Geography, University of Utah, United States
- 8ARVE Research SARL, Switzerland
- 9Department of Archaeology, Max Planck Institute for the Science of Human History (MPG), Germany
Characterization of land cover change in the past is fundamental for understanding the evolution and present state of the earth system, the amount of carbon and nutrient stocks in terrestrial ecosystems, and the role played by land-atmosphere interactions in influencing climate. The estimation of land cover changes using palynology is a mature field, as thousands of sites in Europe have been investigated over the last century. Nonetheless, a quantitative land cover reconstruction at continental scale has been largely missing. Here we present a series of maps detailing the evolution of European forest cover during last 12000 years. Our reconstructions are based on the Modern Analogue Technique (MAT): a calibration dataset is built by coupling modern pollen samples with the corresponding satellite-based forest cover data. Fossil reconstructions are then performed by assigning to every fossil sample the average forest cover of its closest modern analogues. The occurrence of fossil pollen assemblages with no counterparts in modern vegetation represents a known limit of analogue-based methods. To lessen the influence of no-analogue situations, pollen taxa were converted into Plant Functional Types prior to running the MAT algorithm. We then interpolate site-specific reconstructions for each timeslice using a four-dimensional gridding procedure to create continuous gridded maps at continental scale. The performance of the MAT is compared against methodologically independent forest cover reconstructions produced using the REVEALS method; MAT and REVEALS estimates are most of the time in good agreement at a trend level, yet MAT regularly underestimates the occurrence of densely forested situations, requiring the application of a bias correction procedure The calibrated MAT-based maps draw a coherent picture of the establishment of forests in Europe in the early Holocene with the greatest forest cover fractions reconstructed between ~8500 and 6000 cal. yr. BP. This forest maximum is followed by a general decline in all parts of the continent, likely as a result of anthropogenic deforestation. The continuous spatial and temporal nature of our reconstruction, its continental coverage and gridded format make it suitable for climate, hydrological, and biogeochemical modelling, among other uses.
Keywords: Modern analogue technique, Forest cover, Pollen data, remote sensing, Europe, Younger Dryas, Holocene
Received: 17 Nov 2017;
Accepted: 12 Feb 2018.
Edited by:Thomas Giesecke, University of Göttingen, Germany
Reviewed by:Pavel Tarasov, Freie Universität Berlin, Germany
Martin Theuerkauf, University of Greifswald, Germany
Copyright: © 2018 Zanon, Davis, Marquer, Brewer and Kaplan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Mr. Marco Zanon, Christian-Albrechts-Universität zu Kiel, Institute of Pre- and Protohistoric Archaeology, Kiel, Germany, email@example.com