|Carbon and mass balance in a south Swedish ombrotrophic bog: processes and variation during recent centuries.||downloads: 696 | type: pdf | size: 0 kB|
Volume 8 (2011): Article 1
Carbon and mass balance in a south Swedish ombrotrophic bog: processes and variation during recent centuries.
by N. Malmer, G. Svensson and B. Wallén
Published online: 01.01.2011
This study, performed in 1982–2007, deals with the processes in the acrotelm and the subsequent addition of material to the catotelm (accretion) 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 in the catotelm was 20–25% lower in 1900–1980 than in 1800–1900 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 200–770 mm) than the concentration of dissolved organic C (DOC; range 25–55 mg L-1) and mainly determined DOC export. During 1993–2007, 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 1953–1960, 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 50–200 years ago. The DOC exported was accompanied by 25–50% of the N input in litter.
Malmer, N., Svensson, G. & Wallén, B. (2011): Carbon and mass balance in a south Swedish ombrotrophic bog: processes and variation during recent centuries. Mires and Peat 8: Art. 1. (Online: http://www.mires-and-peat.net/pages/volumes/map08/map0801.php)
IMCG and IPS acknowledge the work of the reviewers.