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| Titel |
Carbon concentrations and transformations in peatland pools |
| VerfasserIn |
Pippa Chapman, Joseph Holden, Andrew Baird, Edward Turner, Gemma Dooling, Mike Billett, Rebecca McKenzie, Fraser Leith, Kerry Dinsmore |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250125225
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| Publikation (Nr.) |
 EGU/EGU2016-4775.pdf |
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| Zusammenfassung |
| Peatland pools may act as important features for aquatic and gaseous carbon production,
transformation and release. Peatland restoration often results in new pools being created.
Here we compare aquatic carbon concentrations in nearby natural and artificial pool systems
monitored at three sites in northern Scotland over a three-year period. We found significant
differences in pool water carbon concentrations between pool types with larger dissolved
organic carbon (DOC) and dissolved carbon dioxide (CO2) in artificial pools. The differences
were strong for all sites and occurred in all seasons. Importantly, the DOC outflows
from natural pools were markedly lower than the DOC flowing into natural pools
showing that processes in these pools were transforming and removing the DOC.
These effects were not found in the artificial pools. Data on the composition of the
DOC (absorbance ratios, specific ultraviolet absorbance) suggested that natural
pools tended to have DOC that had been processed, and was older (radiocarbon
dating) while the DOC in artificial pools was young and had not undergone much
biochemical processing. Slope position was an important factor influencing pool DOC
with those pools with a longer upslope contributing area and collecting water with
a longer hillslope residence time having larger DOC concentrations. Dissolved
methane (CH4) concentrations were not significantly different between pool types
but the concentrations were always above atmospheric levels with values ∼ 200
times atmospheric concentrations not uncommon. Dissolved CO2 concentrations in
the artificial pools were extremely large; typically ∼20 times atmospheric levels
while those in natural pools were typically only just above atmospheric levels.
The pools were strong sources of CH4 and CO2 evasion from the peat system.
The smaller size of the artificial pools means that more of their CO2 is stored in
the water until it reaches the stream system, while the larger natural pools have
sufficient wind and wave action to facilitate on site release of CO2 from the pools. |
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