RADIOCARBON DATING OF A RECENT HIGH-LATITUDE PEAT PROFILE - STOR-AMYRAN, NORTHERN SWEDEN

The value of both high-precision (HP) and AMS C-14 determinations in t he fine-resolution dating of recent peat at Stor Amyran, near Umea, no rthern Sweden has been explored. A detailed chronology of accumulation , based an C-14, an occurrence of the Askja AD 1875 tephra and Am-241 measurements has been derived for the last 700 years. This shows signi ficant changes in the mass balance of the peat profile, with minimum r ates of net carbon sequestration overlapping with the period of minimu m spring and summer temperature documented by published tree-ring evid ence. The paper presents a methodology for calculating empirically pas t changes in the rate of net carbon sequestration in boreal peatlands and for exploring the effects of climatic variations (and possible fut ure global warming) on these rates.