%0 Journal Article %T Carbon and mass balance in a south Swedish ombrotrophic bog: processes and variation during recent centuries %A N. Malmer %A G. Svensson %A B. Wall谷n %J Mires and Peat %D 2011 %I %X This study, performed in 1982每2007, deals with the processes in the acrotelm and the subsequent addition (accretion) of material to the catotelm of an ombrotrophic bog in southern Sweden. It is based on analyses of C and N in biomass, necromass and mire water combined with age determinations by 210Pb. The C input to the acrotelm was 102 g m-2 a-1 of which 69% was released through decay and the rest either retained as peat or exported as dissolved organic matter (DOM). The mean C accretion to the catotelm was 20每25% lower in 1900每1980 than in 1800每1900 due to the rising bog surface, continuously increasing acrotelm thickness and total decay loss. Annual runoff, determined indirectly from [Na+] in precipitation and drainage water, varied more (range 200每770 mm) than the concentration of dissolved organic C (DOC; range 25每55 mg L -1) and mainly determined DOC export. During 1993每2007, with high precipitation (mean 880 mm a-1) and mild winters, the mean DOC export and C accretion to the catotelm were equal at 16 g m-2 a-1. During 1953每1960, with lower precipitation (~700 mm a -1) and ※normal§ winters, the DOC export and C accretion were probably about 9 and 23 g m-2, respectively. The release of C to the atmosphere downstream from the bog was correspondingly lower. As a C sink, the bog at present may be half as efficient as it was 50每200 years ago. The DOC exported was accompanied by 25每50% of the N input in litter. %K climate change %K decay loss %K DOC export %K primary production %K nitrogen %U http://www.mires-and-peat.net/map08/map_08_01.pdf