The role of melting dead ice on landscape transformation in the early Holocene in Tuchola Pinewoods, North Poland Michal Slowi  nski a, b, * , Miroslaw Blaszkiewicz a , Achim Brauer b , Bo _ zena Nory  skiewicz c , Florian Ott b , Sebastian Tyszkowski a a Department of Environmental Resources and Geohazards, Institute of Geography and Spatial Organization, Polish Academy of Sciences, Kopernika 19, 87-100 Toru n, Poland b GFZ German Research Centre for Geosciences, Section 5.2 e Climate Dynamics and Landscape Evolution, Telegrafenberg, D-14473 Potsdam, Germany c Institute of Geography, Nicholas Copernicus University, ul. Lwowska 1, 87-100 Toru n, Poland article info Article history: Available online xxx Keywords: Preboreal Macrofossils Pollen Buried ice block Water level changes North Poland abstract On the basis of macrofossil and pollen analyses, AMS 14 C-dating, and geomorphological investigations, we reconstructed the development of hydrological changes during the Lateglacial to early Holocene transition in Tuchola Pinewoods (Bory Tucholskie) in northern Poland. In this region, the Wda River flows in polygenetic valleys, typical for the young glacial landscape of the northern central European lowlands. The middle section of this river provides a suitable setting to demonstrate the environ- mental and hydrological changes in the Late Glacial and early Holocene, because (1) it is a small and well-defined area and (2) the existence of a morphologically preserved river valley from late glacial period. In this study, we focused on a short terrestrial sediment core (48 cm) that represents four phases of landscape evolution during the early Holocene: telmatic, lacustrine, lacustrine-fluvial and alluvial. Abrupt changes in lithology and sediment structures exhibit rapid changes and threshold processes in environmental conditions. The AMS 14 C dating of terrestrial plant remains revealed an age for the basal sediments of 11 223 ± 23 cal BP and thus falls within the Preboreal biozone. Plant macrofossil indicators provide evidence of water level and edaphic changes in the basin. The results of our study demonstrate a strong influence of melting buried ice blocks on the geomorphological development, hydrological changes in the catchment, and the biotic environment in the early Holocene. © 2014 Elsevier Ltd and INQUA. All rights reserved. 1. Introduction The transition from the last glacial into the present interglacial is characterized by a series of short-term and rapid climate fluc- tuations (NGRIP, 2004; Brauer et al., 2008; Bakke et al., 2009). After the retreat of the Fennoscandian ice sheet some 16e18 000 calendar years ago (Marks, 2002) a new landscape began to form in the lowlands of the southern Baltic region. The early phases of landscape evolution in this region were influenced by strongly coupled processes acting on longer, centennial to millennial time scales (e.g. soil formation and vegetation development) super- imposed by repeatedly recurring climate fluctuations on decadal scales (Goslar et al., 1995; Brauer et al., 2008; Bakke et al., 2009; Lauterbach et al., 2011a,b). Another, often underestimated but crucial factor controlling early landscape evolution, are the re- mains of the ice sheet formed during glacial times in the land- scape, namely isolated buried ice blocks and permafrost. Little is known on how these remains of preceding landscapes and climate superimpose on landscape responses to later climate changes. A particular lack of knowledge concerns the time scales at which these memory effects in the landscape continue to affect its evolution. In the northern central European lowlands, melting of buried ice blocks covered with fluvioglacial sediments was an important factor, especially for the development of the regional hydrology. Dead ice melting on the one hand influenced the formation of lakes and river systems and, on the other hand, was itself controlled by local geomorphology and hydrology, soil and vege- tation development, permafrost and, last but not least, climate. * Corresponding author. Department of Environmental Resources and Geo- hazards, Institute of Geography and Spatial Organization, Polish Academy of Sci- ences, Kopernika 19, 87-100 Toru n, Poland. E-mail address: michal.slowinski@geopan.torun.pl (M. Slowi nski). Contents lists available at ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint http://dx.doi.org/10.1016/j.quaint.2014.06.018 1040-6182/© 2014 Elsevier Ltd and INQUA. All rights reserved. Quaternary International xxx (2014) 1e12 Please cite this article in press as: Slowi  nski, M., et al., The role of melting dead ice on landscape transformation in the early Holocene in Tuchola Pinewoods, North Poland, Quaternary International (2014), http://dx.doi.org/10.1016/j.quaint.2014.06.018