Data/hora: 11/06/2024 01:19:32

Provedor de dados: 	5	
País: 	France	
Título: 	Understanding patterns and processes in models of trophic cascades	
Autores: 	Heath, Michael R.; Speirs, Douglas C.; Steele, John H.	
Data: 	2014-01	
Ano: 	2014	
Palavras-chave: 	Bottom-up; Density dependence; Food chain; Food web; Harvesting; Model; Predator-prey; Simulation; Top-down.	
Resumo: 	Climate fluctuations and human exploitation are causing global changes in nutrient enrichment of terrestrial and aquatic ecosystems and declining abundances of apex predators. The resulting trophic cascades have had profound effects on food webs, leading to significant economic and societal consequences. However, the strength of cascades-that is the extent to which a disturbance is diminished as it propagates through a food web-varies widely between ecosystems, and there is no formal theory as to why this should be so. Some food chain models reproduce cascade effects seen in nature, but to what extent is this dependent on their formulation? We show that inclusion of processes represented mathematically as density-dependent regulation of either consumer uptake or mortality rates is necessary for the generation of realistic top-down' cascades in simple food chain models. Realistically modelled bottom-up' cascades, caused by changing nutrient input, are also dependent on the inclusion of density dependence, but especially on mortality regulation as a caricature of, e.g. disease and parasite dynamics or intraguild predation. We show that our conclusions, based on simple food chains, transfer to a more complex marine food web model in which cascades are induced by varying river nutrient inputs or fish harvesting rates.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	https://archimer.ifremer.fr/doc/00171/28249/26505.pdf

DOI:10.1111/ele.12200

https://archimer.ifremer.fr/doc/00171/28249/	
Editor: 	Wiley-blackwell	
Relação: 	info:eu-repo/grantAgreement/EC/FP7/264933/EU//EURO-BASIN	
Formato: 	application/pdf	
Fonte: 	Ecology Letters (1461-023X) (Wiley-blackwell), 2014-01 , Vol. 17 , N. 1 , P. 101-114	
Fonte: 	info:eu-repo/semantics/openAccess

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