 |
| Titel |
Anammox, denitrification and fixed-nitrogen removal in sediments from the Lower St. Lawrence Estuary |
| VerfasserIn |
S. A. Crowe, D. E. Canfield, A. Mucci, B. Sundby, R. Maranger |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 11 ; Nr. 9, no. 11 (2012-11-07), S.4309-4321 |
| Datensatznummer |
250007377
|
| Publikation (Nr.) |
 copernicus.org/bg-9-4309-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| Incubations of intact sediment cores and sediment slurries reveal that
anammox is an important sink for fixed nitrogen in sediments from the Lower
St. Lawrence Estuary (LSLE), where it occurs at a rate of 5.5 ± 1.7 µmol N m−2 h−1. Canonical denitrification occurs at a
rate of 11.3 ± 1.1 µmol N m−2 h−1, and anammox is
thus responsible for up to 33% of the total N2 production. Both
anammox and denitrification are mostly (> 95%) fueled by nitrate and
nitrite produced in situ through benthic nitrification. Nitrification accounts for
> 15% of the benthic oxygen demand and may, therefore, contribute
significantly to the development and maintenance of hypoxic conditions in
the LSLE. The rate of dissimilatory nitrate reduction to ammonium is three
orders of magnitude lower than denitrification and anammox, and it is
insignificant to N-cycling. NH4+ oxidation by sedimentary Fe(III)
and Mn(III/IV) in slurry incubations with N isotope labels did not occur at
measurable rates; moreover, we found no evidence for NH4+ oxidation by
added Mn(III)-pyrophosphate. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|