Data/hora: 11/06/2024 01:09:15

Provedor de dados: 	Institutional Archive of Ifreme (ArchiMer)	
País: 	France	
Título: 	Isotopic Diversity Indices: How Sensitive to Food Web Structure?	
Autores: 	Brind'Amour, Anik; Dubois, Stanislas.	
Data: 	2013-12	
Ano: 	2013	
Resumo: 	Recently revisited, the concept of niche ecology has lead to the formalisation of functional and trophic niches using stable isotope ratios. Isotopic diversity indices (IDI) derived from a set of measures assessing the dispersion/distribution of points in the δ-space were recently suggested and increasingly used in the literature. However, three main critics emerge from the use of these IDI: 1) they fail to account for the isotopic sources overlap, 2) some indices are highly sensitive to the number of species and/or the presence of rare species, and 3) the lack of standardization prevents any spatial and temporal comparisons. Using simulations we investigated the ability of six commonly used IDI to discriminate among different trophic food web structures, with a focus on the first two critics. We tested the sensitivity of the IDI to five food web structures along a gradient of sources overlap, varying from two distinct food chains with differentiated sources to two superimposed food chains sharing two sources. For each of the food web structure we varied the number of species (from 10 to 100 species) and the type of species feeding behaviour (i.e. random or selective feeding). Values of IDI were generally larger in food webs with distinct basal sources and tended to decrease as the superimposition of the food chains increased. This was more pronounced when species displayed food preferences in comparison to food webs where species fed randomly on any prey. The number of species composing the food web also had strong effects on the metrics, including those that were supposedly less sensitive to small sample size. In all cases, computing IDI on food webs with low numbers of species always increases the uncertainty of the metrics. A threshold of ~20 species was detected above which several metrics can be safely used.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	http://archimer.ifremer.fr/doc/00171/28270/26522.pdf

DOI:10.1371/journal.pone.0084198	
Editor: 	Public Library Science	
Relação: 	http://archimer.ifremer.fr/doc/00171/28270/

info:eu-repo/grantAgreement/EC/FP7/312088	
Formato: 	application/pdf	
Fonte: 	Plos One (1932-6203) (Public Library Science), 2013-12 , Vol. 8 , N. 12 , P. -	
Fonte: 	2013 Brind’Amour, Dubois. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

info:eu-repo/semantics/openAccess