A1 Journal article (refereed)
A New Method to Reconstruct Quantitative Food Webs and Nutrient Flows from Isotope Tracer Addition Experiments (2020)

López-Sepulcre, A., Bruneaux, M., Collins, S. M., El-Sabaawi, R., Flecker, A. S., & Thomas, S. A. (2020). A New Method to Reconstruct Quantitative Food Webs and Nutrient Flows from Isotope Tracer Addition Experiments. American Naturalist, 195(6), 964-985. https://doi.org/10.1086/708546

JYU authors or editors

Lopez-Sepulcre, Andres
Bruneaux, Matthieu

Publication details

All authors or editors: López-Sepulcre, Andres; Bruneaux, Matthieu; Collins, Sarah M.; El-Sabaawi, Rana; Flecker, Alexander S.; Thomas, Steven A.

Journal or series: American Naturalist

ISSN: 0003-0147

eISSN: 1537-5323

Publication year: 2020

Volume: 195

Issue number: 6

Pages range: 964-985

Publisher: University of Chicago Press

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1086/708546

Research data link: https://doi.org/10.5061/dryad.8sf7m0chx

Publication open access: Not open

Publication channel open access:

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/70408

Abstract

Understanding how nutrients flow through food webs is central in ecosystem ecology. Tracer addition experiments are powerful tools to reconstruct nutrient flows by adding an isotopically enriched element into an ecosystem and tracking its fate through time. Historically, the design and analysis of tracer studies have varied widely, ranging from descriptive studies to modeling approaches of varying complexity. Increasingly, isotope tracer data are being used to compare ecosystems and analyze experimental manipulations. Currently, a formal statistical framework for analyzing such experiments is lacking, making it impossible to calculate the estimation errors associated with the model fit, the interdependence of compartments, and the uncertainty in the diet of consumers. In this article we develop a method based on Bayesian hidden Markov models and apply it to the analysis of N15‐NH4+ tracer additions in two Trinidadian streams in which light was experimentally manipulated. Through this case study, we illustrate how to estimate N fluxes between ecosystem compartments, turnover rates of N within those compartments, and the associated uncertainty. We also show how the method can be used to compare alternative models of food web structure, calculate the error around derived parameters, and make statistical comparisons between sites or treatments.

Keywords: nutrients (plants); food webs; nutrient uptake (plants); ecosystems (ecology); biomarkers; Bayesian analysis; Markov chains