Drought as a stress driver of ecological changes in peatland - A palaeoecological study of peatland development between 3500 BCE and 200 BCE in central Poland Michał Słowiński a,b, ⁎, Katarzyna Marcisz c,d , Mateusz Płóciennik e , Milena Obremska f , Dominik Pawłowski g , Daniel Okupny h , Sandra Słowińska i , Ryszard Borówka j , Piotr Kittel k , Jacek Forysiak k , Danuta J. Michczyńska l , Mariusz Lamentowicz c,d a Department of Environmental Resources and Geohazards, Institute of Geography and Spatial Organization, Polish Academy of Sciences, Twarda 51/55, 00-818 Warszawa, Poland b GFZ German Research Centre for Geosciences, Section 5.2–Climate Dynamics and Landscape Evolution, Telegrafenberg, D-14473 Potsdam, Germany c Department of Biogeography and Paleoecology, Adam Mickiewicz University, Krygowskiego 10, 61-680 Poznań, Poland d Laboratory of Wetland Ecology and Monitoring, Adam Mickiewicz University, Krygowskiego 10, 61-680 Poznań, Poland e Department of Invertebrate Zoology and Hydrobiology, University of Łódź, Banacha 12/16, 90-237 Łódź, Poland f Institute of Geological Sciences, Polish Academy of Sciences, Twarda 51/55, 00-818 Warsaw, Poland g Institute of Geology, Faculty of Geographical and Geological Science, Adam Mickiewicz University, Maków Polnych, 16 61-606 Poznań, Poland h Institute of Geography, Pedagogical University of Cracow, Podchorążych 2, 30-084 Kraków, Poland i Kujawsko–Pomorski Research Centre, Institute of Technology and Life Sciences in Falenty, Glinki 60, 85-174 Bydgoszcz, Poland j Geology and Paleogeography Unit, Faculty of Geosciences, Institute of Marine and Coastal Sciences, University of Szczecin, Mickiewicza 18, 70-383 Szczecin, Poland k Department of Geomorphology and Palaeogeography, Faculty of Geographical Sciences, University of Łódź, ul. Narutowicza 88, PL 90-139 Łódź, Poland l GADAM Centre of Excellence, Department of Radioisotopes, Institute of Physics – CSE, Silesian University of Technology, Konarskiego 22B, 44-100 Gliwice, Poland abstract article info Article history: Received 7 March 2016 Received in revised form 22 August 2016 Accepted 30 August 2016 Available online xxxx We reconstructed 3300 years (3500 BCE and 200 BCE) of the development history of the Rąbień peatland located in central Poland, using pollen, macrofossil, testate amoebae, Cladocera, Chironomidae and geochemistry. Central Europe, particularly Poland, is characterised by a transitional climate that is influenced by continental and Atlan- tic air masses, which makes this region very sensitive to climate change. Our results demonstrate the high poten- tial of the Rąbień peat record to reconstruct palaeohydrological dynamics. The studied time interval is characterised by two pronounced dry periods: from ~2500 to ~1700 BCE and from ~700 to ~500 BCE, and two significant increases in the water table: from ~1000 to ~800 BCE and from ~500 to ~250 BCE. The timing of the wet shift at 600 BCE corresponds to wet periods at different sites in Central and Eastern Europe. Our investi- gation reveals a more complicated and complex than previously assumed set of climatic relationships in Europe between 3500 BCE and 200 BCE, which might be linked through complex teleconnections of atmospheric circu- lation patterns. Only reconstructions that are based on an understanding of current observations from peatlands and lake ecosystems may lead to a better interpretation of past climate changes. © 2016 Published by Elsevier B.V. Keywords: Palaeohydrology Multi-proxy 4.2 and 2.8 kyr BP events Human impact Solar activity Poland 1. Introduction Changes in hydrology are the main drivers of the processes that occur in peatland ecosystems, e.g. changes in species composition of bi- otic assemblages, and the accumulation and decomposition of organic matter (Charman, 2002; Rydin and Jeglum, 2006). Hydrological changes in mires can also be caused by various non-climatic factors, such as au- togenic processes (Birks and Birks, 2004). Nevertheless, climate remains the dominant factor, with precipitation and temperature affecting the local humidity and hydrological conditions. This is demonstrated by modern observations of relationships between weather conditions and water table changes in peatlands (Marcisz et al., 2014; Słowińska et al., 2010). Peatland ecosystems are sensitive to human impacts, e.g. deforestation (Ireland and Booth, 2012; Lamentowicz et al., 2007; Warner et al., 1989), drainage (De Vleeschouwer et al., 2009; Holden et al., 2011), and pollution (Fialkiewicz-Koziel et al., 2015). Bio-indica- tive properties of different groups of organisms (e.g. Cladocera, Chiron- omidae, testate amoebae or diatoms) and plants (pollen and plant macro-remains) enable us to reconstruct changes that have occurred in the past, based on analyses of biogenic sediments (Chambers et al., 2012; Lamentowicz et al., 2010; Marcisz et al., 2015; Słowiński et al., Palaeogeography, Palaeoclimatology, Palaeoecology xxx (2016) xxx–xxx ⁎ Corresponding author at: Department of Environmental Resources and Geohazards, Institute of Geography and Spatial Organization, Polish Academy of Sciences, Twarda 51/ 55, 00-818 Warszawa, Poland. E-mail address: michal.slowinski@geopan.torun.pl (M. Słowiński). PALAEO-07969; No of Pages 20 http://dx.doi.org/10.1016/j.palaeo.2016.08.038 0031-0182/© 2016 Published by Elsevier B.V. Contents lists available at ScienceDirect Palaeogeography, Palaeoclimatology, Palaeoecology journal homepage: www.elsevier.com/locate/palaeo Please cite this article as: Słowiński, M., et al., Drought as a stress driver of ecological changes in peatland - A palaeoecological study of peatland development between 3500BCE an..., Palaeogeogr. Palaeoclimatol. Palaeoecol. (2016), http://dx.doi.org/10.1016/j.palaeo.2016.08.038