ORIGINAL PAPER A sedimentary record of the rise and fall of the metal industry in Bergslagen, south central Sweden Dan Hammarlund Æ Anson W. Mackay Æ David M. J. Fallon Æ Gemma Pateman Æ Luisa C. Tavio Æ Melanie J. Leng Æ Neil L. Rose Received: 16 May 2007 / Accepted: 2 June 2007 / Published online: 21 June 2007 Ó Springer Science+Business Media B.V. 2007 Abstract Detailed stratigraphic analyses of sedi- ments deposited in Lake Botja ¨rnen, a small boreal forest lake in the shield terrain of central Sweden, clearly reflect progressively increasing human impact on terrestrial and aquatic ecosystems following settlement and establishment of an iron industry in the 17th century. Rising frequencies of pollen and spores from light-demanding plants provide evidence of extensive forest clearance for charcoal and timber production, which peaked in the early 20th century. An associated increase in catchment erosion is reflected by changing carbon and nitrogen elemental content and carbon–isotope composition of sediment organic matter and by increased magnetic suscepti- bility of the sediments. Records of air-borne pollu- tants (lead, zinc and sulphur) can be correlated to the development of local and regional mining and metal industry as inferred from historical accounts. Rapid recession of the iron industry led to re-forestation and recovery of the aquatic nutrient status to pre- industrial conditions over the past 100 years. The chronology of the sediment succession, which is based on 210 Pb and 137 Cs radionuclide data in combination with radiocarbon dating, is confirmed by historical lead pollution trends established for the region. Keywords Pollution history Á Carbon isotopes Á C:N ratio Á Inorganic elements Á Pollen accumulation rate Á Rarefaction Introduction The Bergslagen region in south central Sweden has a long history of ore mining and metal industry. Systematic utilization of iron oxides and complex metal sulphide deposits began in the 13th century, spread and diversified during the following centuries, and prospered in response to an increased demand for metal products during the Industrial Revolution in the 19th century (Alvstam and Korhonen 1995). Envi- ronmental impacts related to these activities were D. Hammarlund (&) GeoBiosphere Science Centre, Quaternary Sciences, Lund University, So ¨lvegatan 12, SE-223 62 Lund, Sweden e-mail: dan.hammarlund@geol.lu.se A. W. Mackay Á N. L. Rose Environmental Change Research Centre, Department of Geography, UCL, Gower Street, London WC1E 6BT, UK D. M. J. Fallon Á G. Pateman Á L. C. Tavio Department of Geography, UCL, Gower Street, London WC1E 6BT, UK M. J. Leng NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham NG12 5GG, UK M. J. Leng School of Geography, University of Nottingham, Nottingham NG7 2RD, UK 123 J Paleolimnol (2008) 39:463–475 DOI 10.1007/s10933-007-9124-z