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Beyond carbon and nitrogen: guidelines for estimating three‐dimensional isotopic niche space

Isotopic niche has typically been characterized through carbon and nitrogen ratios and most modeling approaches are limited to two dimensions. Yet, other stable isotopes can provide additional power to resolve questions associated with foraging, migration, dispersal and variations in resource use. T...

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Autores principales: Rossman, Sam, Ostrom, Peggy H., Gordon, Forrest, Zipkin, Elise F.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4834325/
https://www.ncbi.nlm.nih.gov/pubmed/27110351
http://dx.doi.org/10.1002/ece3.2013
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author Rossman, Sam
Ostrom, Peggy H.
Gordon, Forrest
Zipkin, Elise F.
author_facet Rossman, Sam
Ostrom, Peggy H.
Gordon, Forrest
Zipkin, Elise F.
author_sort Rossman, Sam
collection PubMed
description Isotopic niche has typically been characterized through carbon and nitrogen ratios and most modeling approaches are limited to two dimensions. Yet, other stable isotopes can provide additional power to resolve questions associated with foraging, migration, dispersal and variations in resource use. The ellipse niche model was recently generalized to n‐dimensions. We present an analogous methodology which incorporates variation across three stable dimensions to estimate the significant features of a population's isotopic niche space including: 1) niche volume (referred to as standard ellipsoid volume, SEV), 2) relative centroid location (CL), 3) shape and 4) area of overlap between multiple ellipsoids and 5) distance between two CLs. We conducted a simulation study showing the accuracy and precision of three dimensional niche models across a range of values. Importantly, the model correctly identifies differences in SEV and CL among populations, even with small sample sizes and in cases where the absolute values cannot precisely be recovered. We use these results to provide guidelines for sample size in conducting multivariate isotopic niche modeling. We demonstrate the utility of our approach with a case study of three bottlenose dolphin populations which appear to possess largely overlapping niches when analyzed with only carbon and nitrogen isotopes. Upon inclusion of sulfur, we see that the three dolphin ecotypes are in fact segregated on the basis of salinity and find the stable isotope niche of inshore bottlenose dolphins significantly larger than coastal and offshore populations.
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spelling pubmed-48343252016-04-22 Beyond carbon and nitrogen: guidelines for estimating three‐dimensional isotopic niche space Rossman, Sam Ostrom, Peggy H. Gordon, Forrest Zipkin, Elise F. Ecol Evol Original Research Isotopic niche has typically been characterized through carbon and nitrogen ratios and most modeling approaches are limited to two dimensions. Yet, other stable isotopes can provide additional power to resolve questions associated with foraging, migration, dispersal and variations in resource use. The ellipse niche model was recently generalized to n‐dimensions. We present an analogous methodology which incorporates variation across three stable dimensions to estimate the significant features of a population's isotopic niche space including: 1) niche volume (referred to as standard ellipsoid volume, SEV), 2) relative centroid location (CL), 3) shape and 4) area of overlap between multiple ellipsoids and 5) distance between two CLs. We conducted a simulation study showing the accuracy and precision of three dimensional niche models across a range of values. Importantly, the model correctly identifies differences in SEV and CL among populations, even with small sample sizes and in cases where the absolute values cannot precisely be recovered. We use these results to provide guidelines for sample size in conducting multivariate isotopic niche modeling. We demonstrate the utility of our approach with a case study of three bottlenose dolphin populations which appear to possess largely overlapping niches when analyzed with only carbon and nitrogen isotopes. Upon inclusion of sulfur, we see that the three dolphin ecotypes are in fact segregated on the basis of salinity and find the stable isotope niche of inshore bottlenose dolphins significantly larger than coastal and offshore populations. John Wiley and Sons Inc. 2016-03-09 /pmc/articles/PMC4834325/ /pubmed/27110351 http://dx.doi.org/10.1002/ece3.2013 Text en © 2016 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Research
Rossman, Sam
Ostrom, Peggy H.
Gordon, Forrest
Zipkin, Elise F.
Beyond carbon and nitrogen: guidelines for estimating three‐dimensional isotopic niche space
title Beyond carbon and nitrogen: guidelines for estimating three‐dimensional isotopic niche space
title_full Beyond carbon and nitrogen: guidelines for estimating three‐dimensional isotopic niche space
title_fullStr Beyond carbon and nitrogen: guidelines for estimating three‐dimensional isotopic niche space
title_full_unstemmed Beyond carbon and nitrogen: guidelines for estimating three‐dimensional isotopic niche space
title_short Beyond carbon and nitrogen: guidelines for estimating three‐dimensional isotopic niche space
title_sort beyond carbon and nitrogen: guidelines for estimating three‐dimensional isotopic niche space
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4834325/
https://www.ncbi.nlm.nih.gov/pubmed/27110351
http://dx.doi.org/10.1002/ece3.2013
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