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| Titel |
Beyond the Fe-P-redox connection: preferential regeneration of phosphorus from organic matter as a key control on Baltic Sea nutrient cycles |
| VerfasserIn |
T. Jilbert, C. P. Slomp, B. G. Gustafsson, W. Boer |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 8, no. 6 ; Nr. 8, no. 6 (2011-06-28), S.1699-1720 |
| Datensatznummer |
250005965
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| Publikation (Nr.) |
 copernicus.org/bg-8-1699-2011.pdf |
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| Zusammenfassung |
| Patterns of regeneration and burial of phosphorus (P) in the Baltic Sea are
strongly dependent on redox conditions. Redox varies spatially along water
depth gradients and temporally in response to the seasonal cycle and
multidecadal hydrographic variability. Alongside the well-documented link
between iron oxyhydroxide dissolution and release of P from Baltic Sea
sediments, we show that preferential remineralization of P with respect to
carbon (C) and nitrogen (N) during degradation of organic matter plays a key
role in determining the surplus of bioavailable P in the water column.
Preferential remineralization of P takes place both in the water column and
upper sediments and its rate is shown to be redox-dependent, increasing as
reducing conditions become more severe at greater water-depth in the deep
basins. Existing Redfield-based biogeochemical models of the Baltic may
therefore underestimate the imbalance between N and P availability for
primary production, and hence the vulnerability of the Baltic to sustained
eutrophication via the fixation of atmospheric N. However, burial of organic
P is also shown to increase during multidecadal intervals of expanded
hypoxia, due to higher net burial rates of organic matter around the margins
of the deep basins. Such intervals may be characterized by basin-scale
acceleration of all fluxes within the P cycle, including productivity,
regeneration and burial, sustained by the relative accessibility of the
water column P pool beneath a shallow halocline. |
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