Skip Navigation

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Collos, Y.
Right arrow Articles by Richard, S.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Collos, Y.
Right arrow Articles by Richard, S.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Journal of Plankton Research Vol.23 no.3 pp.263-270, 2001
© Oxford University Press 2001

Carbon Fixation, Ammonium Uptake and Regeneration in an Equatorial Lake: Biological Versus Physical Control

Y. Collos, A. Vaquer, A. M. Johnston1,, V. Pons, B. Bibent and S. Richard2,

Ecosystèmes Lagunaires (ers 2011 Cnrs), Université Montpellier Ii, Cc093, 34095 Montpellier Cedex 5, France, 1 Plants, Soils And Environment, Scottish Crop Research Institute, Invergowrie Dd2 5da, Uk And 2 Hydreco, Laboratoire Environnement De Petit Saut, Bp 823, 97388 Kourou Cedex, France

Ammonium uptake and regeneration were measured in the euphotic zone of Petit Saut Lake, French Guyana, to examine nitrogen cycling in this recently flooded equatorial forest environment. Am-monium regeneration rates were extremely high (mostly in the range 1–6 µmol N l–1 h–1), and are due to the very high grazing rates of the microzooplankton, which consumed between 56 and 95% of the phytoplankton production in any given incubation. These regeneration rates were about an order of magnitude higher than the net ammonium uptake rates. This imbalance is probably due to dissolved organic nitrogen release during grazing. At the bottom of the euphotic zone (4–5 m), photosynthetic bacteria are responsible for ammonium uptake. Diffusion-driven ammonium fluxes are an order of magnitude lower than biologically driven fluxes. Therefore, ammonium fluxes are dominated by biology rather than by physics in this lake.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.