title: Integrative modelling reveals mechanisms linking productivity and plant species richness.
abstract: How ecosystem productivity and species richness are interrelated is one of the most debated subjects in the history of ecology. Decades of intensive study have yet to discern the actual mechanisms behind observed global patterns. Here, by integrating the predictions from multiple theories into a single model and using data from 1,126 grassland plots spanning five continents, we detect the clear signals of numerous underlying mechanisms linking productivity and richness. We find that an integrative model has substantially higher explanatory power than traditional bivariate analyses. In addition, the specific results unveil several surprising findings that conflict with classical models. These include the isolation of a strong and consistent enhancement of productivity by richness, an effect in striking contrast with superficial data patterns. Also revealed is a consistent importance of competition across the full range of productivity values, in direct conflict with some (but not all) proposed models. The promotion of local richness by macroecological gradients in climatic favourability, generally seen as a competing hypothesis, is also found to be important in our analysis. The results demonstrate that an integrative modelling approach leads to a major advance in our ability to discern the underlying processes operating in ecological systems.
authors.affiliation: US Geological Survey, Wetland and Aquatic Research Center, 700 Cajundome Boulevard, Lafayette, Louisiana 70506, USA.
authors.forename: James B
authors.initials: JB
authors.lastname: Grace
authors.affiliation: Department of Biology, 206 Winston Hall, Wake Forest University, Box 7325 Reynolda Station, Winston-Salem, North Carolina 27109, USA.
authors.forename: T Michael
authors.initials: TM
authors.lastname: Anderson
authors.affiliation: Ecology, Evolution, and Behavior, University of Minnesota, 1987 Upper Buford Circle, St Paul, Minnesota 55108, USA.
authors.forename: Eric W
authors.initials: EW
authors.lastname: Seabloom
authors.affiliation: Ecology, Evolution, and Behavior, University of Minnesota, 1987 Upper Buford Circle, St Paul, Minnesota 55108, USA.
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Borer
authors.affiliation: Department of Wildland Resources and the Ecology Center, Utah State University, 5230 Old Main, Logan, Utah 84322, USA.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Adler
authors.affiliation: Department of Physiological Diversity, Helmholtz Center for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.|German Centre for Integrative Biodiversity Research (iDiv), Deutscher Platz 5e, D-04103 Leipzig, Germany.|Martin Luther University Halle-Wittenberg, Am Kirchtor 1, 06108 Halle (Saale), Germany.
authors.forename: W Stanley
authors.initials: WS
authors.lastname: Harpole
authors.affiliation: Ecology and Biodiversity Group, Department of Biology, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands.
authors.forename: Yann
authors.initials: Y
authors.lastname: Hautier
authors.affiliation: Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Schleusenstrasse 1, Wilhelmshaven D-26381, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Hillebrand
authors.affiliation: Ecology, Evolution, and Behavior, University of Minnesota, 1987 Upper Buford Circle, St Paul, Minnesota 55108, USA.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Lind
authors.affiliation: Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, Tartu 51005, Estonia.
authors.forename: Meelis
authors.initials: M
authors.lastname: Pärtel
authors.affiliation: School of Environmental and Forest Sciences, University of Washington, Box 354115, Seattle, Washington 98195-4115, USA.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Bakker
authors.affiliation: School of Natural Sciences, Zoology, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.
authors.forename: Yvonne M
authors.initials: YM
authors.lastname: Buckley
authors.affiliation: Department of Biological Sciences, Imperial College London, Silwood Park, Ascot, Berkshire SL5 7PY, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Crawley
authors.affiliation: Department of Zoology, University of Wisconsin, 430 Lincoln Drive, Madison, Wisconsin 53706, USA.
authors.forename: Ellen I
authors.initials: EI
authors.lastname: Damschen
authors.affiliation: Department of Ecology and Evolutionary Biology, UCB 334, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Kendi F
authors.initials: KF
authors.lastname: Davies
authors.affiliation: Grassland Soil and Water Research Laboratory, United States Department of Agriculture Agricultural Research Service, 808 East Blackland Road, Temple, Texas 76502, USA.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Fay
authors.affiliation: #15 Queensland University of Technology, School of Earth, Environment and Biological Sciences, Brisbane, Queensland 4001, Australia.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Firn
authors.affiliation: Department of Entomology, University of Maryland, College Park, 4112 Plant Sciences, College Park, Maryland 20742, USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Gruner
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Andy
authors.initials: A
authors.lastname: Hector
authors.affiliation: School of Biological Sciences, 348 Manter Hall, University of Nebraska, Lincoln, Nebraska 68588, USA.
authors.forename: Johannes M H
authors.initials: JM
authors.lastname: Knops
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 Ecology and Evolutionary Biology, UCB 334, University of Colorado, Boulder, Colorado 80309, USA.
authors.forename: Brett A
authors.initials: BA
authors.lastname: Melbourne
authors.affiliation: Department of Ecology, Environment, and Evolution, La Trobe University, Bundoora, Victoria 3083, Australia.
authors.forename: John W
authors.initials: JW
authors.lastname: Morgan
authors.affiliation: Department of Zoology, University of Wisconsin, 430 Lincoln Drive, Madison, Wisconsin 53706, USA.
authors.forename: John L
authors.initials: JL
authors.lastname: Orrock
authors.affiliation: CSIRO Land and Water, Private Bag 5, Wembley, Western Australia, 6913, Australia.
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Prober
authors.affiliation: Department of Biology, Colorado State University, 1878 Campus Delivery, Fort Collins, Colorado 80526, USA.
authors.forename: Melinda D
authors.initials: MD
authors.lastname: Smith
mesh_terms: D044822:Biodiversity; D003163:Competitive Behavior; D005843:Geography; D065948:Grassland; D008954:Models, Biological; D010944:Plants / Q000145:classification* / Q000378:metabolism*