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| Titel |
Multivariate benthic ecosystem functioning in the Arctic – benthic fluxes explained by environmental parameters in the southeastern Beaufort Sea |
| VerfasserIn |
H. Link, G. Chaillou, A. Forest, D. Piepenburg, P. Archambault |
| 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 ; 10, no. 9 ; Nr. 10, no. 9 (2013-09-10), S.5911-5929 |
| Datensatznummer |
250085326
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| Publikation (Nr.) |
 copernicus.org/bg-10-5911-2013.pdf |
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| Zusammenfassung |
| The effects of climate change on Arctic marine ecosystems and their
biogeochemical cycles are difficult to predict given the complex physical,
biological and chemical interactions among the ecosystem components. We
studied benthic biogeochemical fluxes in the Arctic and the influence of
short-term (seasonal to annual), long-term (annual to decadal) and other
environmental variability on their spatial distribution to provide a
baseline for estimates of the impact of future changes. In summer 2009, we
measured fluxes of dissolved oxygen, nitrate, nitrite, ammonia, soluble
reactive phosphate and silicic acid at the sediment–water interface at eight
sites in the southeastern Beaufort Sea at water depths from 45 to 580 m. The
spatial pattern of the measured benthic boundary fluxes was heterogeneous.
Multivariate analysis of flux data showed that no single or reduced
combination of fluxes could explain the majority of spatial variation,
indicating that oxygen flux is not representative of other nutrient
sink–source dynamics. We tested the influence of eight environmental
parameters on single benthic fluxes. Short-term environmental parameters
(sinking flux of particulate organic carbon above the bottom, sediment
surface Chl a) were most important for explaining oxygen, ammonium and
nitrate fluxes. Long-term parameters (porosity, surface manganese and iron
concentration, bottom water oxygen concentrations) together with δ13Corg signature explained most of the spatial variation in
phosphate, nitrate and nitrite fluxes. Variation in pigments at the sediment
surface was most important to explain variation in fluxes of silicic acid.
In a model including all fluxes synchronously, the overall spatial
distribution could be best explained (57%) by the combination of
sediment Chl a, phaeopigments, δ13Corg, surficial manganese
and bottom water oxygen concentration. We conclude that it is necessary to
consider long-term environmental variability along with rapidly ongoing
environmental changes to predict the flux of oxygen and nutrients across
Arctic sediments even at short timescales. Our results contribute to
improve ecological models predicting the impact of climate change on the
functioning of marine ecosystems. |
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