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Research article - Peer-reviewed, 2022

The coordination of green-brown food webs and their disruption by anthropogenic nutrient inputs

Zelnik, Yuval R.; Manzoni, Stefano; Bommarco, Riccardo;


Aim Our goal was to quantify nitrogen flows and stocks in green-brown food webs in different ecosystems, how they differ across ecosystems and how they respond to nutrient enrichment. Location Global. Time period Contemporary. Major taxa studied Plants, phytoplankton, macroalgae, invertebrates, vertebrates and zooplankton. Methods Data from >500 studies were combined to estimate nitrogen stocks and fluxes in green-brown food webs in forests, grasslands, brackish environments, seagrass meadows, lakes and oceans. We compared the stocks, fluxes and metabolic rates of different functional groups within each food web. We also used these estimates to build a dynamical model to test the response of the ecosystems to nutrient enrichment. Results We found surprising symmetries between the green and brown channels across ecosystems, in their stocks, fluxes and consumption coefficients and mortality rates. We also found that nitrogen enrichment, either organic or inorganic, can disrupt this balance between the green and brown channels. Main conclusions Linking green and brown food webs reveals a previously hidden symmetry between herbivory and detritivory, which appears to be a widespread property of natural ecosystems but can be disrupted by anthropogenic nitrogen additions.


anthropogenic perturbations; food webs; nutrient cycling; nutrient subsidies; primary productivity

Published in

Global Ecology and Biogeography

2022, volume: 31, number: 11, pages: 2270-2280
Publisher: WILEY

Authors' information

Swedish University of Agricultural Sciences, Department of Ecology
Manzoni, Stefano
Stockholm University
Swedish University of Agricultural Sciences, Department of Ecology

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