Abstract
Peatlands play an important role in the global carbon (C) cycle, by acting as a large, long-term C sink. The C sink is sustained by a high water level that inhibits decomposition of organic matter. The C gas dynamics are therefore sensitive to changes in water level, and in climatically different years a peatland can vary from a sink to a source of C. We measured carbon dioxide (CO 2) and methane (CH 4) fluxes from vegetation communities ranging from hummocks to low lawns in a blanket bog. After a one-year calibration period the water level was both lowered and raised experimentally and the changes in vegetation composition and gas fluxes were monitored during a further year. In all vegetation communities the water level drawdown increased the respiration rate and decreased methane emission; rising water level decreased respiration and increased methane emissions. The effect of altered water level on photosynthesis depended on species composition. Water level drawdown decreased photosynthesis in most communities; rising water level decreased the photosynthesis of hummocks species, and increased the photosynthesis of Rhynchospora alba.
Original language | English |
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Pages (from-to) | 65-83 |
Number of pages | 19 |
Journal | Suo |
Volume | 60 |
Issue number | 3-4 |
Publication status | Published - 2009 |
Keywords
- Drainage
- Ecohydrology
- Flooding
- Methane
- Peatland
- Photosynthesis
- Racomitrium
- Respiration
- Rhynchospora alba
- Sphagnum