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Titel |
Spring bloom community change modifies carbon pathways and C : N : P : Chl a stoichiometry of coastal material fluxes |
VerfasserIn |
K. Spilling, A. Kremp, R. Klais, K. Olli, T. Tamminen |
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 ; 11, no. 24 ; Nr. 11, no. 24 (2014-12-19), S.7275-7289 |
Datensatznummer |
250117748
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Publikation (Nr.) |
copernicus.org/bg-11-7275-2014.pdf |
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Zusammenfassung |
Diatoms and dinoflagellates are major bloom-forming phytoplankton groups
competing for resources in the oceans and coastal seas. Recent evidence
suggests that their competition is significantly affected by climatic
factors under ongoing change, modifying especially the conditions for
cold-water, spring bloom communities in temperate and Arctic regions. We
investigated the effects of phytoplankton community composition on spring
bloom carbon flows and nutrient stoichiometry in multiyear mesocosm
experiments. Comparison of differing communities showed that community
structure significantly affected C accumulation parameters, with highest
particulate organic carbon (POC) buildup and dissolved organic carbon (DOC)
release in diatom-dominated communities. In terms of inorganic nutrient
drawdown and bloom accumulation phase, the dominating groups behaved as
functional surrogates. Dominance patterns, however, significantly affected
C : N : P : Chl a ratios over the whole bloom event: when diatoms were
dominant, these ratios increased compared to dinoflagellate dominance or
mixed communities. Diatom-dominated communities sequestered carbon up to
3.6-fold higher than the expectation based on the Redfield ratio, and 2-fold
higher compared to dinoflagellate dominance. To our knowledge, this is the
first experimental report of consequences of climatically driven shifts in
phytoplankton dominance patterns for carbon sequestration and related
biogeochemical cycles in coastal seas. Our results also highlight the need
for remote sensing technologies with taxonomical resolution, as the C : Chl a ratio was strongly dependent on community composition and bloom stage.
Climate-driven changes in phytoplankton dominance patterns will have
far-reaching consequences for major biogeochemical cycles and need to be
considered in climate change scenarios for marine systems. |
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