Paiva, Vitor Hugo Rodrigues and Ballutaud, Marine and Travers-Trolet, Morgane and Marchal, Paul and Dubois, Stanislas F. and Giraldo, Carolina and Parnell, Andrew and Nuche-Pascual, M. Teresa and Lefebvre, Sébastien (2022) Inferences to estimate consumer’s diet using stable isotopes: Insights from a dynamic mixing model. PLoS ONE, 17 (2). pp. 1-26. ISSN 1932-6203

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Abstract

Stable isotope ratios are used to reconstruct animal diet in trophic ecology via mixing models. Several assumptions of stable isotope mixing models are critical, i.e., constant trophic discrimination factor and isotopic equilibrium between the consumer and its diet. The isotopic turnover rate (λ and its counterpart the half-life) affects the dynamics of isotopic incorporation for an organism and the isotopic equilibrium assumption: λ involves a time lag between the real assimilated diet and the diet estimated by mixing models at the individual scale. Current stable isotope mixing model studies consider neither this time lag nor even the dynamics of isotopic ratios in general. We developed a mechanistic framework using a dynamic mixing model (DMM) to assess the contribution of λ to the dynamics of isotopic incorporation and to estimate the bias induced by neglecting the time lag in diet reconstruction in conventional static mixing models (SMMs). The DMM includes isotope dynamics of sources (denoted δs), λ and frequency of diet-switch (ω). The results showed a significant bias generated by the SMM compared to the DMM (up to 50% of differences). This bias can be strongly reduced in SMMs by averaging the isotopic variations of the food sources over a time window equal to twice the isotopic half-life. However, the bias will persist (*15%) for intermediate values of the ω/λ ratio. The inferences generated using a case study highlighted that DMM enhanced estimates of consumer’s diet, and this could avoid misinterpretation in ecosystem functioning, food-web structure analysis and underlying biological processes.

Item Type:	Article
Keywords:	Inferences; estimate; consumer’s diet; stable isotopes; Insights; dynamic; mixing model;
Academic Unit:	Faculty of Science and Engineering > Mathematics and Statistics Faculty of Science and Engineering > Research Institutes > Hamilton Institute Faculty of Social Sciences > Research Institutes > Irish Climate Analysis and Research Units, ICARUS
Item ID:	18996
Identification Number:	https://doi.org/10.1371/journal.pone.0263454
Depositing User:	Andrew Parnell
Date Deposited:	09 Oct 2024 14:15
Journal or Publication Title:	PLoS ONE
Publisher:	Public Library of Science
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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