title: Intraspecific leaf trait variability along a boreal-to-tropical community diversity gradient.
abstract: Disentangling the mechanisms that shape community assembly across diversity gradients is a central matter in ecology. While many studies have explored community assembly through species average trait values, there is a growing understanding that intraspecific trait variation (ITV) can also play a critical role in species coexistence. Classic biodiversity theory hypothesizes that higher diversity at species-rich sites can arise from narrower niches relative to species-poor sites, which would be reflected in reduced ITV as species richness increases. To explore how ITV in woody plant communities changes with species richness, we compiled leaf trait data (leaf size and specific leaf area) in a total of 521 woody plant species from 21 forest communities that differed dramatically in species richness, ranging from boreal to tropical rainforests. At each forest, we assessed ITV as an estimate of species niche breadth and we quantified the degree of trait overlap among co-occurring species as a measure of species functional similarity. We found ITV was relatively invariant across the species richness gradient. In addition, we found that species functional similarity increased with diversity. Contrary to the expectation from classic biodiversity theory, our results rather suggest that neutral processes or equalizing mechanisms can be acting as potential drivers shaping community assembly in hyperdiverse forests.
authors.affiliation: Departamento de Biogeografía y Cambio Global. Museo Nacional de Ciencias Naturales- CSIC, Madrid, Spain.
authors.forename: Cristina C
authors.initials: CC
authors.lastname: Bastias
authors.affiliation: Department of Biology. University of Maryland, College Park, MD, United States of America.|Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, United States of America.
authors.forename: Claire
authors.initials: C
authors.lastname: Fortunel
authors.affiliation: Departamento de Biogeografía y Cambio Global. Museo Nacional de Ciencias Naturales- CSIC, Madrid, Spain.|Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, Móstoles, Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Valladares
authors.affiliation: INRA, UMR "Ecologie des Forets de Guyane", Kourou Cedex 97387, French Guiana.
authors.forename: Christopher
authors.initials: C
authors.lastname: Baraloto
authors.affiliation: Departamento de Biogeografía y Cambio Global. Museo Nacional de Ciencias Naturales- CSIC, Madrid, Spain.|Institut für Biologie, Geobotanik, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
authors.forename: Raquel
authors.initials: R
authors.lastname: Benavides
authors.affiliation: Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
authors.forename: William
authors.initials: W
authors.lastname: Cornwell
authors.affiliation: Smithsonian Tropical Research Institute, Balboa, Ancón, Panamá.|Department of Zoology, University of Oxford, South Parks Road, Oxford, United Kingdom.|School of Environment, Natural Resources and Geography, Bangor University, Bangor LL57 2DG, United Kingdom.
authors.forename: Lars
authors.initials: L
authors.lastname: Markesteijn
authors.affiliation: Departamento de Ecologia, Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: Alexandre A
authors.initials: AA
authors.lastname: de Oliveira
authors.affiliation: Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Jardim Botânico, Rio de Janeiro, Brazil.|Universidade Federal Rural do Rio de Janeiro-UFRRJ. Departamento de Ciencias Ambientais-DCA. Instituto de Florestas-, Seropédica, Rio de Janeiro, Brazil.
authors.forename: Jeronimo B B
authors.initials: JB
authors.lastname: Sansevero
authors.affiliation: Department of Biology. University of Maryland, College Park, MD, United States of America.|Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, United States of America.
authors.forename: Marcel C
authors.initials: MC
authors.lastname: Vaz
authors.affiliation: Department of Biology. University of Maryland, College Park, MD, United States of America.|Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, United States of America.
authors.forename: Nathan J B
authors.initials: NJ
authors.lastname: Kraft
mesh_terms: D044822:Biodiversity; D065928:Forests; D010641:Phenotype; D018515:Plant Leaves / Q000502:physiology*; D014197:Trees