|
|
|
| Registros recuperados: 14 | |
|
| |
|
| |
|
| |
|
|
| Boucher, G.; Clavier, Jacques; Garrigue, Claire. |
| Ammonium affinity of New Caledonia lagoon benthic communities was measured during the course of 33 #in situ$ enrichment experiments, in order to estimate the contribution of benthos to ammonium fluxes. Ammonium chloride was injected into enclosures pushed into the sediment ... Ammonium kinetic uptake was then followed for two yours. Grey-sand bottom displayed the highest affinity was the same order of magnitude. Macrophytes, and microphytes (when macrophytes are absent), account for the bulk of ammonium bottom uptake. As a result, grey-sand bottoms with their dense macrophyte cover represent a sink for water column nitrogen and play a key role in nutrient cycling of the lagoon. (D'après résumé d'auteur) |
| Tipo: Text |
Palavras-chave: LAGON; SEDIMENT; BENTHOS; AMMONIUM; FLUX; CORRELATION NUMERIQUE; MACROPHYTE; CYCLE DE L'AZOTE. |
| Ano: 1994 |
URL: http://www.documentation.ird.fr/hor/fdi:39878 |
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
|
| Simon-Sylvestre, G.; Calvet, R.. |
| La mise au point d’une technique simple, pour l’étude de la nitrification dans un milieu poreux modèle, permet d’envisager de faire varier assez facilement les conditions d’expérimentation et d’approndir ainsi nos connaissances sur ce processus biologique. Les résultats antérieurs de plusieurs chercheurs, à savoir l’influence néfaste des ions ammonium sur la nitrification, sont retrouvés dans une première application de ce modèle. Il apparaît également dans une autre expérimentation, réalisée en présence d’une phase solide adsorbante (argile), que seuls les cations NH+4 désorbés peuvent être oxydés, en quantité variable suivant la nature de l’argile, et que la toxicité d’une substance xénobiotique ajoutée est modifiée par suite de son adsorption,... |
| Tipo: Journal Article |
Palavras-chave: NITRIFICATION; ARGILE; AMMONIUM. |
| Ano: 1987 |
URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PUB9100000019018102&uri=/notices/prodinra1/2009/07/ |
| |
|
| |
|
| |
|
|
| Herrmann, B.; Mattsson, M.; Jones, S.K.; Cellier, P.; Milford, C.; Sutton, M.A.; Schjoerring, J.K.; Neftel, A.. |
| Stomatal ammonia compensation points (Xs) of grass species on a mixed fertilized grassland were determined by measurements of apoplastic [NH4+] and [H>+] in the field. Calculated Xs values were compared with in-canopy atmospheric NH3 concentration (Xa) measurements.Leaf apoplastic [NH4+] increased by a factor of two from the lowest level in the canopy to the top level. Bulk leaf [NH4+] and especially [NO3-] slightly increased at the bottom of the canopy and these concentrations were very high in senescent plant litter. Calculated Xs values were below atmospheric Xs at all canopy levels measured, indicating that the grassland was characterized by NH3 deposition before cutting. This was confirmed by the Xa profile, showing the lowest Xa close to the... |
| Tipo: Journal Article |
Palavras-chave: AMMONIUM; POINT DE COMPENSATION STOMATIQUE; APOPLASTE; DEPOT. |
| Ano: 2009 |
URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD20095f1ce749&uri=/notices/prodinra1/2011/04/ |
| |
| Registros recuperados: 14 | |
|
|
|
