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| Titel |
Dynamics of phytoplankton community structure in the South China Sea in response to the East Asian aerosol input |
| VerfasserIn |
C. Guo, J. Yu, T.-Y. Ho, L. Wang, S. Song, L. Kong, H. Liu |
| 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 ; 9, no. 4 ; Nr. 9, no. 4 (2012-04-26), S.1519-1536 |
| Datensatznummer |
250006958
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| Publikation (Nr.) |
 copernicus.org/bg-9-1519-2012.pdf |
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| Zusammenfassung |
| Recent studies have demonstrated atmospheric deposition as an important
source of bioreactive compounds to the ocean. The South China Sea (SCS),
where aerosol loading is among the highest in the world, however, is poorly
studied, particularly on the in situ response of phytoplankton community
structures to atmospheric deposition. By conducting a series of microcosm
bioassays at different hydrographical locations and simulating different
aerosol event scales, we observed both positive and negative responses to
the input of East Asian (EA) aerosol with high nitrogen (N) and trace metal
contents, in terms of biomass, composition and physiological characteristics
of phytoplankton communities. High levels of aerosol loading relieved
phytoplankton nitrogen and trace metal limitations in SCS, and thus
increased total phytoplankton biomass, enhanced their physiological
indicators (e.g. photosynthetic efficiency) and shifted phytoplankton
assemblages from being dominated by picoplankton to microphytoplanton,
especially diatoms. However, under low levels of aerosol loading, the
composition shift and biomass accumulation were not apparent, suggesting
that the stimulation effects might be counterbalanced by enhanced grazing
mortality indicated by increased abundance of protist grazers. Trace metal
toxicity of the aerosols might also be the reason for the reduction of
picocyanobacteria when amended with high EA aerosols. The magnitude and
duration of the deposition event, as well as the hydrographical and trophic
conditions of receiving waters are also important factors when predicting
the influence of an aerosol deposition event. Our results demonstrated
different responses of phytoplankton and microbial food web dynamics to
different scales of atmospheric input events in SCS and highlighted the need
for achieving an accurate comprehension of atmospheric nutrient on the
biogeochemical cycles of the oceans. |
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