title: Extensions of Island Biogeography Theory predict the scaling of functional trait composition with habitat area and isolation.
abstract: The Theory of Island Biogeography (TIB) predicts how area and isolation influence species richness equilibrium on insular habitats. However, the TIB remains silent about functional trait composition and provides no information on the scaling of functional diversity with area, an observation that is now documented in many systems. To fill this gap, we develop a probabilistic approach to predict the distribution of a trait as a function of habitat area and isolation, extending the TIB beyond the traditional species-area relationship. We compare model predictions to the body-size distribution of piscivorous and herbivorous fishes found on tropical reefs worldwide. We find that small and isolated reefs have a higher proportion of large-sized species than large and connected reefs. We also find that knowledge of species body-size and trophic position improves the predictions of fish occupancy on tropical reefs, supporting both the allometric and trophic theory of island biogeography. The integration of functional ecology to island biogeography is broadly applicable to any functional traits and provides a general probabilistic approach to study the scaling of trait distribution with habitat area and isolation.
authors.affiliation: UMR 9190 MARBEC (MARine Biodiversity, Exploitation and Conservation), Université de Montpellier, Place Eugène Bataillon - bât 24 - CC093, 34095, Montpellier Cedex 05, France.|Département de biologie, chimie et géographie, Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, QC, G5L 3A1, Canada.|Quebec Center for Biodiversity Science, Montréal, QC, Canada.
authors.forename: Claire
authors.initials: C
authors.lastname: Jacquet
authors.affiliation: UMR 9190 MARBEC (MARine Biodiversity, Exploitation and Conservation), Université de Montpellier, Place Eugène Bataillon - bât 24 - CC093, 34095, Montpellier Cedex 05, France.|Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Mouillot
authors.affiliation: IRD UMR "Entropie", Labex"Corail", Université de Perpignan, 66000, Perpignan, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Kulbicki
authors.affiliation: Quebec Center for Biodiversity Science, Montréal, QC, Canada.|Chaire de recherche en Écologie intégrative, Département de biologie, Université de Sherbrooke, 2500 Boulevard Université, Sherbrooke, QC, J1K 2R1, Canada.
authors.forename: Dominique
authors.initials: D
authors.lastname: Gravel
mesh_terms: D063147:Animal Distribution; D000818:Animals; D044822:Biodiversity; D057894:Coral Reefs; D017753:Ecosystem; D005399:Fishes / Q000502:physiology*; D062312:Islands; D008954:Models, Biological; D011157:Population Dynamics
keywords: Allometric theory; body-size; food web; island biogeography; tropical reefs