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Titolo:
AN IMPROVED MODEL OF CARBON AND NUTRIENT DYNAMICS IN THE MICROBIAL FOOD-WEB IN MARINE ENCLOSURES
Autore:
BARETTABEKKER JG; BARETTA JW; HANSEN AS; RIEMANN B;
Indirizzi:
DANISH HYDRAUL INST,JOINT DEPT,ECOL MODELLING CTR,AGERN ALLE 5 DK-2970 HORSHOLM DENMARK VKI DK-2970 HORSHOLM DENMARK NATL ENVIRONM RES INST DK-4000 ROSKILDE DENMARK
Titolo Testata:
Aquatic microbial ecology
fascicolo: 1, volume: 14, anno: 1998,
pagine: 91 - 108
SICI:
0948-3055(1998)14:1<91:AIMOCA>2.0.ZU;2-G
Fonte:
ISI
Lingua:
ENG
Soggetto:
DISSOLVED ORGANIC-MATTER; SEAS-ECOSYSTEM-MODEL; SIMULATION; PLANKTON; WATERS; ALGAE; LAKE;
Keywords:
MICROBIAL FOOD WEB; LUXURY UPTAKE; NUTRIENT UPTAKE; NUTRIENT CYCLES; ECOSYSTEM MODEL; MESOCOSM;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
28
Recensione:
Indirizzi per estratti:
Citazione:
J.G. Barettabekker et al., "AN IMPROVED MODEL OF CARBON AND NUTRIENT DYNAMICS IN THE MICROBIAL FOOD-WEB IN MARINE ENCLOSURES", Aquatic microbial ecology, 14(1), 1998, pp. 91-108

Abstract

A description of an improved dynamic simulation model of a marine enclosure is given. New features in the model are the inclusion of picoalgae and mixotrophs; the ability of bacteria to take up dissolved inorganic nutrients directly; and, for the phytoplankton functional groups,the inclusion of luxury uptake and the decoupling of the nutrient uptake dynamics from carbon-assimilation dynamics. This last feature implies dynamically variable phosphorus/carbon and nitrogen/carbon ratios. The model was calibrated with experimental results from enclosure experiments carried out in Knebel Vig, a shallow microtidal land-locked fjord in Denmark, and verified with results from enclosure experiments in Hylsfjord, a deep and salinity-stratified Norwegian fjord. Both observations and model simulations showed dominance of a microbial food web in control enclosures with low productivity. In Nand P-enriched enclosures a classical food web developed, while an intermediate system was found in N-, P-and Si-enriched enclosures. Mixotrophic flagellates were most important in the nutrient-limited control enclosures where they accounted for 49% of the pigmented biomass and about 48% of the primary production. Lumping the mixotrophs in the simulation model with either the autotrophic or the heterotrophic functional groups reduced total primary production by 74%. Model-derived, time-averaged phosphorus budgets suggested that bacteria competed with algae for orthophosphate in the control enclosure, but not in the enclosure to which N and P had been added, where bacteria functioned as net mineralisers of phosphate. In the N, P and Si enclosure, bacteria took up only 10% of theamount of orthophosphate taken up by the primary producers, passing most of the organic phosphorus on to their grazers, the heterotrophic nanoflagellates, and mineralising only a small fraction directly. Inclusion of luxury nutrient uptake affected the simulation of the nutrient-enriched enclosures, while the decoupling of carbon and nutrient dynamics affected the simulation of the control enclosure. Without these 2processes it was not possible to simulate the carbon and nutrient dynamics in the different enclosures adequately with the same parameterisation.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 15/01/21 alle ore 23:29:42