 |
| Titel |
Degradation changes stable carbon isotope depth profiles in palsa peatlands |
| VerfasserIn |
J. P. Krüger, J. Leifeld, C. Alewell |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 12 ; Nr. 11, no. 12 (2014-06-24), S.3369-3380 |
| Datensatznummer |
250117480
|
| Publikation (Nr.) |
 copernicus.org/bg-11-3369-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Palsa peatlands are a significant carbon pool in the global carbon cycle and
are projected to change by global warming due to accelerated permafrost thaw.
Our aim was to use stable carbon isotopes as indicators of palsa degradation.
Depth profiles of stable carbon isotopes generally reflect organic matter
dynamics in soils with an increase of δ13C values during aerobic
decomposition and stable or decreasing δ13C values with depth
during anaerobic decomposition. Stable carbon isotope depth profiles of
undisturbed and degraded sites of hummocks as well as hollows at three palsa
peatlands in northern Sweden were used to investigate the degradation
processes. The depth patterns of stable isotopes clearly differ between
intact and degraded hummocks at all sites. Erosion and cryoturbation at the
degraded sites significantly changes the stable carbon isotope depth
profiles. At the intact hummocks the uplifting of peat material by permafrost
is indicated by a turning in the δ13C depth trend, and this
assessment is supported by a change in the C / N ratios. For hollows
isotope patterns were less clear, but some hollows and degraded hollows in
the palsa peatlands show differences in their stable carbon isotope depth
profiles indicating enhanced degradation rates. We conclude that the
degradation of palsa peatlands by accelerated permafrost thawing can be
identified with stable carbon isotope depth profiles. At intact hummocks
δ13C depth patterns display the uplifting of peat material by a
change in peat decomposition processes. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|