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| Titel |
Response of heterotrophic and autotrophic microbial plankton to inorganic and organic inputs along a latitudinal transect in the Atlantic Ocean |
| VerfasserIn |
S. Martínez-García, E. Fernández, A. Calvo-Díaz, E. Marañón, X. A. G. Morán, E. Teira |
| 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 ; 7, no. 5 ; Nr. 7, no. 5 (2010-05-25), S.1701-1713 |
| Datensatznummer |
250004778
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| Publikation (Nr.) |
 copernicus.org/bg-7-1701-2010.pdf |
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| Zusammenfassung |
The effects of inorganic and/or organic nutrient inputs on phytoplankton and
heterotrophic bacteria have never been concurrently assessed in open ocean
oligotrophic communities over a wide spatial gradient. We studied the
effects of potentially limiting inorganic (nitrate, ammonium, phosphate,
silica) and organic nutrient (glucose, aminoacids) inputs added separately
as well as jointly, on microbial plankton biomass, community structure and
metabolism in five microcosm experiments conducted along a latitudinal
transect in the Atlantic Ocean (from 26° N to 29° S).
Primary production rates increased up to 1.8-fold. Bacterial respiration and
microbial community respiration increased up to 14.3 and 12.7-fold
respectively. Bacterial production and bacterial growth efficiency increased
up to 58.8-fold and 2.5-fold respectively. The largest increases were
measured after mixed inorganic-organic nutrients additions. Changes in
microbial plankton biomass were small as compared with those in metabolic
rates. A north to south increase in the response of heterotrophic bacteria
was observed, which could be related to a latitudinal gradient in phosphorus
availability. Our results suggest that organic matter inputs will result in
a predominantly heterotrophic versus autotrophic response and in increases
in bacterial growth efficiency, particularly in the southern hemisphere.
Subtle differences in the initial environmental and biological conditions
are likely to result in differential microbial responses to inorganic and
organic matter inputs. |
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