Vegetation and climate history in the Westeifel Volcanic Field (Germany) during the past 11 000 years based on annually laminated lacustrine maar sediments THOMAS LITT, CHRISTIAN SCHO ¨ LZEL, NORBERT K ¨ UHL AND ACHIM BRAUER BOREAS Litt, T., Sch¨olzel, C., K¨uhl, N. & Brauer, A. 2009 (November): Vegetation and climate history in the Westeifel Volcanic Field (Germany) during the past 11 000 years based on annually laminated lacustrine maar sediments. Boreas, Vol. 38, pp. 679–690. 10.1111/j.1502-3885.2009.00096.x. ISSN 0300-9483. Lakes Holzmaar and Meerfelder Maar are located in the Westeifel Volcanic Field less than 10 km apart. Both maar lakes are well known for their annually laminated (varved) sediments covering the past 15 000 years. Here, we focus on reconstructing the history of Holocene vegetation, human impact and climate using high-resolution pollen data. Detailed correlation between the two records using palynologically defined tie-points provides for the first time a test of the precision of the individual varve chronologies. The high-resolution pollen records of both Holzmaar and Meerfelder Maar show continuous natural successions of vegetation during the early and mid-Holocene controlled by the development of soil, climate, immigration and competitive expansion of thermophilous tree species. From 6500 varve yr BP onwards, human impact became an increasingly more important factor. Given the high chron- ological precision of both records, regional similarities, but also local differences of anthropogenically influenced vegetation changes, can be recognized. The reconstructed July temperature between 8500 and 5000 varve yr BP is around 1 1C higher than today, most likely in response to higher summer insolation related to orbital forcing. High variability of reconstructed July and January temperatures as well as annual precipitation around 5000 varve yr BP is a prominent climatic signal. This is consistent with other records in several areas of Europe which also identify this period as climatically highly variable. Thomas Litt (e-mail: t.litt@uni-bonn.de) and Norbert K ¨ uhl, Steinmann Institute of Geology, Mineralogy and Pa- laeontology, University of Bonn, Nussallee 8, 53115 Bonn, Germany; Christian Sch ¨ olzel, Meteorological Institute, University of Bonn, Auf dem H ¨ ugel 20, 53121 Bonn, Germany; Achim Brauer, Deutsches GeoForschungsZentrum GFZ, Telegrafenberg, 14473 Potsdam, Germany; received 18th July 2008, accepted 13th February 2009. Reconstructing regional variability of climate change requires detailed comparison and correlation of high- resolution palaeoclimatic proxy data with precise chronologies for each record. Annually laminated lacustrine sediments represent ideal chronologies, espe- cially when also clearly defined marker layers, such as volcanic ashes, are present. The Westeifel Volcanic Field is well known for its maar lakes providing long, annually laminated sediment records of palaeoenvir- onmental changes. In two of these lakes, Holzmaar and Meerfelder Maar, varve chronologies have been estab- lished for the Weichselian Lateglacial and the Holocene (Zolitschka 1998; Brauer et al. 1999a; Zolitschka et al. 2000). During recent years, detailed chronostratigraphical and climatostratigraphical analysis has allowed sub- division of the Lateglacial in the Eifel region by com- bining varve counting and palynology (Brauer et al. 1999b; Litt & Stebich 1999; Litt et al. 2001, 2003). When comparing several such records, this approach also permits detection of gaps of a few decades up to a few centuries, thus providing a valuable tool for precise re- gional palaeoenvironmental studies (Brauer et al. 2001). In this article, we present a synthesis of the Holocene vegetation and climate history of the Westeifel Volcanic Field based on high-resolution analysis of annually la- minated lacustrine sediments from lakes Holzmaar and Meerfelder Maar. For cross-checking both independent varve chronologies, specific palynological signals are used as marker horizons, which is an approach that is meaningful because both lakes are located only a few kilometres apart. To further improve on the re- construction of the palaeoclimate development of the region during the past 11 000 years, pollen-climate transfer functions are used and compared between both records and with other palaeoclimate reconstructions from NW Europe where different proxy data or meth- ods have been used. Study area and methods Study area Lakes Holzmaar (HZM, 5017 0 N, 6153 0 E; 425 m a.s.l.) and Meerfelder Maar (MFM, 5016 0 N, 6145 0 E; 336.5 m a.s.l.) are located within the Westeifel Volcanic Field less than 10km apart (Fig. 1). The present lake surface of MFM, which is the largest maar of the West- eifel Volcanic Field, is 0.248 km 2 compared to 0.058 km 2 of HZM. The maximum water depths of both lakes are presently similar (MFM 17 m and HZM 20 m). DOI 10.1111/j.1502-3885.2009.00096.x r 2009 The Authors, Journal compilation r 2009 The Boreas Collegium