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| Gevaert, F; Creach, A; Davoult, D; Migne, A; Levavasseur, G; Arzel, Pierre; Holl, Ac; Lemoine, Y. |
| Photosynthetic activity in thalli of Laminaria saccharina (Lamouroux) was followed in situ in the upper subtidal zone of a Northern Brittany rocky shore (Roscoff, France), using a submersible pulse amplitude modulated (PAM) fluorometer. Two fluorescence parameters, the effective quantum yield of photosystem II (Phi(PSII)) and the relative electron transport rate (rETR), were estimated at various stages of a tidal cycle from 10:00 to 18:30 h, and different light conditions due to variations of water depth and position of the sun. The Phi(PSII) decreased strongly during the ebb tide, essentially due to a drop in the maximal fluorescence level for light-adapted samples (F-m'). This was the result of increasing non-photochemical quenching (NPQ). Algae totally... |
| Tipo: Text |
Palavras-chave: Laminaria saccharina; Photoprotection; Xanthophyll cycle; Chlorophyll fluorescence; Diurnal tidal cycles; Diving PAM. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10191/7592.pdf |
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| Plus, Martin; Chapelle, Annie; Lazure, Pascal; Auby, Isabelle; Levavasseur, G; Verlaque, M; Belsher, Thomas; Deslous-paoli, Jean-marc; Zaldivar, J; Murray, C. |
| A three-dimensional model coupling physical and biological processes for the whole Than lagoon (Mediterranean coast of France) was developed in order to assess the relationships between macrophytes and the oxygen and nitrogen cycles. Ten species have been inserted as forcing variables in the model. Plankton dynamics, shellfish cultivation impact and mineralization of organic matter are also considered, as well as nutrient and oxygen exchanges between the sediment and the water column. Simulations with and without the macrophytes have shown that the system can be characterized as having a highly structured pattern involving lagoon nitrogen and oxygen cycles. This pattern is created by the combined influence of macrophytes, watershed and oyster farming.... |
| Tipo: Text |
Palavras-chave: Thau lagoon; Biogeochemical cycles; Ecological modelling; Macrophytes. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/2003/publication-459.pdf |
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