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| Titel |
Nutritive and photosynthetic ecology of subsurface chlorophyll maxima in Canadian Arctic waters |
| VerfasserIn |
J. Martin, J. É. Tremblay, N. M. Price |
| 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. 12 ; Nr. 9, no. 12 (2012-12-21), S.5353-5371 |
| Datensatznummer |
250007475
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| Publikation (Nr.) |
 copernicus.org/bg-9-5353-2012.pdf |
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| Zusammenfassung |
| Assessments of carbon and nitrogen (N) assimilation in
Canadian Arctic waters confirmed the large contribution of subsurface
chlorophyll maxima (SCM) to total water-column production from spring to
late fall. Although SCM communities showed acclimation to low irradiance and
greater nitrate (NO3−) availability, their productivity was
generally constrained by light and temperature. During spring–early summer,
most of the primary production at the SCM was sustained by NO3−,
with an average f-ratio (i.e., relative contribution of NO3− uptake
to total N uptake) of 0.74 ± 0.26. The seasonal decrease in
NO3− availability and irradiance, coupled to the build up of
ammonium (NH4+), favoured a transition toward a predominantly
regenerative system (f-ratio = 0.37 ± 0.20) during
late summer and fall. Results emphasize the need to adequately consider SCM
when estimating primary production and to revisit ecosystem model
parameters in highly stratified Arctic waters. |
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