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Degradation legacy and current water levels as predictors of carbon emissions from two fen sites.
- Source :
- Mires & Peat; 2021, Issue 27, p1-15, 15p
- Publication Year :
- 2021
-
Abstract
- Drainage-induced shifts in physicochemical peat properties are irreversible on a decadal time span. We investigated whether carbon emissions from fen peat can be estimated using two proxies: current water levels and peat properties (as affected by drainage history, i.e. degradation legacy). We collected bare peat monoliths from a long-term drained and an undrained fen. In a crossed design, half of the monoliths was kept wet and the other half was drained. Highest carbon dioxide (CO<subscript>2</subscript>) emissions came from the originally undrained peat under low water levels (607 mmol m<superscript>-2</superscript> d<superscript>-1</superscript>). Overall, CO<subscript>2</subscript> emissions were primarily determined by drainage history, with 141 % higher emissions from the originally undrained peat. In addition, low current water levels correlated with 42 % higher emissions. Highest methane (CH4) emissions were measured in the originally undrained peat under high water levels (123 mmol m<superscript>-2</superscript> d<superscript>-1</superscript>). Overall, CH4 emissions were primarily determined by current water levels, with 430 % higher emissions under high water levels. In addition, the originally undrained peat had 180 % higher emissions. The lower C efflux from originally drained peat correlated with lower concentrations of methanogens and of easily-degradable carbon substrate (cellulose). We conclude that substrate limitation in long-term drained fens ensures low baseline carbon emissions, which provides opportunities for renewed carbon sequestration by rewetting. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 1819754X
- Issue :
- 27
- Database :
- Supplemental Index
- Journal :
- Mires & Peat
- Publication Type :
- Academic Journal
- Accession number :
- 153348311
- Full Text :
- https://doi.org/10.19189/MaP.2020.SNPG.StA.2149