title: Weighting and indirect effects identify keystone species in food webs.
abstract: Species extinctions are accelerating globally, yet the mechanisms that maintain local biodiversity remain poorly understood. The extinction of species that feed on or are fed on by many others (i.e. 'hubs') has traditionally been thought to cause the greatest threat of further biodiversity loss. Very little attention has been paid to the strength of those feeding links (i.e. link weight) and the prevalence of indirect interactions. Here, we used a dynamical model based on empirical energy budget data to assess changes in ecosystem stability after simulating the loss of species according to various extinction scenarios. Link weight and/or indirect effects had stronger effects on food-web stability than the simple removal of 'hubs', demonstrating that both quantitative fluxes and species dissipating their effects across many links should be of great concern in biodiversity conservation, and the potential for 'hubs' to act as keystone species may have been exaggerated to date.
authors.affiliation: Research Center for Engineering Ecology and Nonlinear Science, North China Electric Power University, Beijing, 102206, China.|Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Research Center for Engineering Ecology and Nonlinear Science, North China Electric Power University, Beijing, 102206, China.
authors.forename: Huayong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK.
authors.forename: Eoin J
authors.initials: EJ
authors.lastname: O'Gorman
authors.affiliation: Research Center for Engineering Ecology and Nonlinear Science, North China Electric Power University, Beijing, 102206, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Tian
authors.affiliation: School of Electronic Engineering and Computer Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
authors.forename: Athen
authors.initials: A
authors.lastname: Ma
authors.affiliation: Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, 80523, USA.|Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, 80523, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Moore
authors.affiliation: Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, 28403, USA.|Duke Network Analysis Center, Duke University, Durham, NC, 27708, USA.
authors.forename: Stuart R
authors.initials: SR
authors.lastname: Borrett
authors.affiliation: Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK.
authors.forename: Guy
authors.initials: G
authors.lastname: Woodward
mesh_terms: D003247:Conservation of Natural Resources; D053476:Extinction, Biological; D020387:Food Chain; D008954:Models, Biological; D013045:Species Specificity
keywords: Carbon flux; centrality; energy budget; quantitative food web; robustness; secondary extinction; sequential deletion; species loss