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| Titel |
Physiological constraints on the global distribution of Trichodesmium – effect of temperature on diazotrophy |
| VerfasserIn |
E. Breitbarth, A. Oschlies, J. LaRoche |
| 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 ; 4, no. 1 ; Nr. 4, no. 1 (2007-01-15), S.53-61 |
| Datensatznummer |
250001498
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| Publikation (Nr.) |
 copernicus.org/bg-4-53-2007.pdf |
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| Zusammenfassung |
| The cyanobacterium Trichodesmium is an important
link in the global nitrogen cycle due to
its significant input of atmospheric nitrogen to the ocean.
Attempts to incorporate Trichodesmium in ocean biogeochemical circulation models
have, so far, relied on the observed
correlation between temperature and Trichodesmium abundance.
This correlation may result in part from a direct effect of temperature on Trichodesmium growth rates
through the control of cellular biochemical
processes, or indirectly through temperature influence on mixed layer depth, light
and nutrient regimes. Here we present results indicating that the observed
correlation of Trichodesmium with temperature in the field reflects primarily the direct
physiological effects of temperature on diazotrophic growth of
Trichodesmium. Trichodesmium IMS-101 (an isolate of Trichodesmium)
could acclimate and grow at temperatures ranging
from 20 to 34°C. Maximum growth rates (μmax=0.25 day–1)
and maximum nitrogen fixation rates (0.13 mmol N mol POC−1 h–1)
were measured within 24 to 30°C. Combining this empirical relationship with global
warming scenarios derived from state-of-the-art climate models sets a
physiological constraint on the future distribution of Trichodesmium that could
significantly affect the future nitrogen input into oligotrophic waters by this diazotroph. |
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