title: Herbivores and nutrients control grassland plant diversity via light limitation.
abstract: Human alterations to nutrient cycles and herbivore communities are affecting global biodiversity dramatically. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local diversity through light limitation, and herbivory rescued diversity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light.
authors.affiliation: Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, Minnesota 55108, USA.
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Borer
authors.affiliation: Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, Minnesota 55108, USA.
authors.forename: Eric W
authors.initials: EW
authors.lastname: Seabloom
authors.affiliation: Department of Entomology, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Gruner
authors.affiliation: Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: W Stanley
authors.initials: WS
authors.lastname: Harpole
authors.affiliation: Institute for Chemistry and Biology of the Marine Environment, Carl-von- Ossietzky University, 26382 Wilhelmshaven, Oldenburg, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Hillebrand
authors.affiliation: Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, Minnesota 55108, USA.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Lind
authors.affiliation: Department of Wildland Resources and the Ecology Center, Utah State University, Logan, Utah 84322, USA.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Adler
authors.affiliation: Instituto de Investigaciones Marinas y Costeras (IIMyC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata 7600 , Argentina.
authors.forename: Juan
authors.initials: J
authors.lastname: Alberti
authors.affiliation: Department of Biology, Wake Forest University, Winston-Salem, North Carolina 27109, USA.
authors.forename: T Michael
authors.initials: TM
authors.lastname: Anderson
authors.affiliation: School of Environmental and Forest Sciences, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Bakker
authors.affiliation: Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Lori
authors.initials: L
authors.lastname: Biederman
authors.affiliation: Agricultural Research Service (ARS), United States Department of Agriculture, Fort Collins, Colorado 80526, USA.
authors.forename: Dana
authors.initials: D
authors.lastname: Blumenthal
authors.affiliation: Deptartment of Forest, Rangeland and Watershed Stewardship, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: Cynthia S
authors.initials: CS
authors.lastname: Brown
authors.affiliation: Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824, USA.
authors.forename: Lars A
authors.initials: LA
authors.lastname: Brudvig
authors.affiliation: 1] ARC Centre of Excellence for Environmental Decisions, School of Biological Sciences, The University of Queensland, Queensland 4072, Australia [2] School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Yvonne M
authors.initials: YM
authors.lastname: Buckley
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto Scarborough, Ontario M1C 1A4, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Cadotte
authors.affiliation: State Key Laboratory of Grassland and Agro-Ecosystems, Research Station of Alpine Meadow and Wetland Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000 Gansu, China.
authors.forename: Chengjin
authors.initials: C
authors.lastname: Chu
authors.affiliation: Division of Biological Sciences, University of California, San Diego, California 92093, USA.
authors.forename: Elsa E
authors.initials: EE
authors.lastname: Cleland
authors.affiliation: Department of Biology, Imperial College at Silwood Park, Ascot, Berkshire SL5 7PY, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Crawley
authors.affiliation: Instituto de Investigaciones Marinas y Costeras (IIMyC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata 7600 , Argentina.
authors.forename: Pedro
authors.initials: P
authors.lastname: Daleo
authors.affiliation: Department of Zoology, University of Wisconsin, Madison, Wisconsin 53706, USA.
authors.forename: Ellen I
authors.initials: EI
authors.lastname: Damschen
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado, Boulder Colorado 80309, USA.
authors.forename: Kendi F
authors.initials: KF
authors.lastname: Davies
authors.affiliation: US Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, Oregon 97331, USA.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: DeCrappeo
authors.affiliation: State Key Laboratory of Grassland and Agro-Ecosystems, Research Station of Alpine Meadow and Wetland Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, 730000 Gansu, China.
authors.forename: Guozhen
authors.initials: G
authors.lastname: Du
authors.affiliation: Queensland University of Technology, Biogeosciences, Brisbane, Queensland 4001, Australia.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Firn
authors.affiliation: Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, Minnesota 55108, USA.
authors.forename: Yann
authors.initials: Y
authors.lastname: Hautier
authors.affiliation: Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Heckman
authors.affiliation: Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, UK.
authors.forename: Andy
authors.initials: A
authors.lastname: Hector
authors.affiliation: School of Environmental and Forest Sciences, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Janneke
authors.initials: J
authors.lastname: HilleRisLambers
authors.affiliation: Instituto de Investigaciones Marinas y Costeras (IIMyC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata 7600 , Argentina.
authors.forename: Oscar
authors.initials: O
authors.lastname: Iribarne
authors.affiliation: Deptartment of Forest, Rangeland and Watershed Stewardship, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: Julia A
authors.initials: JA
authors.lastname: Klein
authors.affiliation: School of Biological Sciences, University of Nebraska, Lincoln, Nebraska 68588, USA.
authors.forename: Johannes M H
authors.initials: JM
authors.lastname: Knops
authors.affiliation: Berkeley Initiative for Global Change Biology, University of California, Berkeley 94704, USA.
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: La Pierre
authors.affiliation: Department of Plant Biology, University of Illinois at Urbana-Champaign, llinois 61820, USA.
authors.forename: Andrew D B
authors.initials: AD
authors.lastname: Leakey
authors.affiliation: Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: MacDougall
authors.affiliation: Department of Plant & Soil Sciences, University of Kentucky, Lexington, Kentucky 40546, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: McCulley
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado, Boulder Colorado 80309, USA.
authors.forename: Brett A
authors.initials: BA
authors.lastname: Melbourne
authors.affiliation: Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Mitchell
authors.affiliation: Australian Research Center for Urban Ecology, c/o School of Botany, University of Melbourne, Victoria 3010, Australia, and School of Biological Sciences, Monash University, Victoria 3800, Australia.
authors.forename: Joslin L
authors.initials: JL
authors.lastname: Moore
authors.affiliation: Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Brent
authors.initials: B
authors.lastname: Mortensen
authors.affiliation: Department of Zoology, Oregon State University, Corvallis, Oregon 97331, USA.
authors.forename: Lydia R
authors.initials: LR
authors.lastname: O'Halloran
authors.affiliation: Department of Zoology, University of Wisconsin, Madison, Wisconsin 53706, USA.
authors.forename: John L
authors.initials: JL
authors.lastname: Orrock
authors.affiliation: Instituto de Investigaciones Marinas y Costeras (IIMyC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata 7600 , Argentina.
authors.forename: Jesús
authors.initials: J
authors.lastname: Pascual
authors.affiliation: CSIRO Ecosystem Sciences, Wembley, West Australia 6913, Australia.
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Prober
authors.affiliation: US Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, Oregon 97331, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Pyke
authors.affiliation: Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf 8903, Switzerland.
authors.forename: Anita C
authors.initials: AC
authors.lastname: Risch
authors.affiliation: Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf 8903, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Schuetz
authors.affiliation: Deptartment of Forest, Rangeland and Watershed Stewardship, Colorado State University, Fort Collins, Colorado 80523, USA.
authors.forename: Melinda D
authors.initials: MD
authors.lastname: Smith
authors.affiliation: Lancaster Environment Center, Lancaster University, Lancaster LA1 4YQ, UK.
authors.forename: Carly J
authors.initials: CJ
authors.lastname: Stevens
authors.affiliation: Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Lauren L
authors.initials: LL
authors.lastname: Sullivan
authors.affiliation: Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Williams
authors.affiliation: Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, Minnesota 55108, USA.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Wragg
authors.affiliation: Department of Biology, Duke University, Durham, North Carolina 27708, USA.
authors.forename: Justin P
authors.initials: JP
authors.lastname: Wright
authors.affiliation: Department of Entomology, University of California, Davis, California 95616, USA.
authors.forename: Louie H
authors.initials: LH
authors.lastname: Yang
mesh_terms: D044822:Biodiversity; D002980:Climate; D005068:Eutrophication / Q000187:drug effects / Q000528:radiation effects*; D005843:Geography; D060434:Herbivory / Q000502:physiology*; D006802:Human Activities; D038622:Internationality; D008027:Light; D009584:Nitrogen / Q000378:metabolism / Q000494:pharmacology; D010944:Plants / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects*; D006109:Poaceae / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D013997:Time Factors
chemical_list: D009584:Nitrogen