|
|
|
|
|
| Lhelguen, S; Madec, C; Lecorre, P. |
| Uptake of nitrogenous nutrients (NO3-, NO2-, NH4+ and urea) by phytoplankton was measured over an annual cycle at a coastal station in the well-mixed waters of the western English Channel. Seasonal changes of nitrogen uptake showed a single, but spread-out, maximum in summer. The phytoplankton took up the various forms of nitrogen simultaneously. Ammonium uptake accounted for 48% of the total nitrogen uptake and was quantitatively important from the beginning of spring until early autumn. Nitrate uptake was relatively less important (32% of total nitrogen uptake) though nitrate was the major component of available inorganic nitrogen. Nitrate uptake rates were comparable to those of ammonium in winter and spring, but were much lower than the latter in... |
| Tipo: Text |
Palavras-chave: NITROGEN; UPTAKE; PHYTOPLANKTON; ENGLISH CHANNEL; SEASONAL CYCLE. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21129/18749.pdf |
| |
|
|
| Hoch, Thierry; Menesguen, Alain; Bentley, D. |
| A simple model of the nitrogen cycle in the Channel is proposed. Based on the long-term circulation, this box-model permits the description of the spring phytoplankton bloom in the whole Channel. Spring western thermal stratification has not been taken into account; consequently, the earliest phytoplanktonic development is observed in the eastern Channel, followed by the western, deeper part. This model also shows the influence of nutrient supply from the rivers on the Channel ecosystem, and particularly the influence of the river Seine on the chlorophyll concentrations along the eastern French coast. Comparison of calculated data with measurements shows a fairly good agreement in the eastern Channel but discrepancies are encountered for the western part.... |
| Tipo: Text |
Palavras-chave: CHANNEL; BOX-MODEL; NITROGEN; PHYTOPLANKTON. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21128/18748.pdf |
| |
|
|
|
