Data/hora: 09/06/2024 10:24:46

Provedor de dados: | 5
País: | France

Título:

Couplage de modèles trophiques et effets combinés de la pêche et du climat

Coupling trophodynamic models for assessing the combined effects of fishing and climate

Autores: | Travers, Morgane.
Data: | 2009-04-02
Ano: | 2009
Palavras-chave: | Modèle end-to-end; Couplage de modèle; Réseau trophique; Sud- Benguela; Effets combinés; Changement climatique; Surexploitation; End-to-end model; Model coupling; Food web; Southern Benguela; Combined effects; Climate change; Overfishing.
Resumo: | Overfishing and climate change are now recognized to have important effects on marine ecosystem functioning but uncertainties remains about their combined effects. Using a modelling approach this thesis aims at assessing how the top-down effects of fishing and the bottom-up effects of climate combine themselves within the food web. A preliminary review highlighted the lack of end-to-end model applicable as it stands to our study case - the southern Benguela - and suitable to study the combined effects of fishing and climate. Coupling the plankton model ROMS-N2P2Z2D2 and the fish model OSMOSE appeared as an innovative method allowing to develop an appropriate tool meeting our objectives. The importance of two-way coupling via the predation process is first illustrated by the study of spatial and temporal variabilities of the feedback term, and then by the comparison of plankton and ecosystem dynamics when there is feedback or not. Simulating climate and fishing scenarios show that the combined effects of these factors are generally smaller than the sum of their individual effects. This result reflects the strong resilience of the ecosystem to external perturbations, induced by the numerous and weak trophic interactions between organisms. In agreement with hypotheses of trophic functioning based on the intensity of primary production and predators diversity, the study of the trophic pyramid show that bottom-up control dominates in the southern Benguela, i.e. that climate has stronger effects on the trophic functioning of this ecosystem than fishing.
Tipo: | Text
Idioma: | Francês
Identificador: | http://archimer.ifremer.fr/doc/00003/11445/7993.pdf
Editor: | Université Pierre et Marie Curie
Relação: | http://archimer.ifremer.fr/doc/00003/11445/
Formato: | application/pdf