title: Energetic and ecological constraints on population density of reef fishes.
abstract: Population ecology has classically focused on pairwise species interactions, hindering the description of general patterns and processes of population abundance at large spatial scales. Here we use the metabolic theory of ecology as a framework to formulate and test a model that yields predictions linking population density to the physiological constraints of body size and temperature on individual metabolism, and the ecological constraints of trophic structure and species richness on energy partitioning among species. Our model was tested by applying Bayesian quantile regression to a comprehensive reef-fish community database, from which we extracted density data for 5609 populations spread across 49 sites around the world. Our results indicate that population density declines markedly with increases in community species richness and that, after accounting for richness, energetic constraints are manifested most strongly for the most abundant species, which generally are of small body size and occupy lower trophic groups. Overall, our findings suggest that, at the global scale, factors associated with community species richness are the major drivers of variation in population density. Given that populations of species-rich tropical systems exhibit markedly lower maximum densities, they may be particularly susceptible to stochastic extinction.
authors.affiliation: Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia barnechedr@gmail.com.
authors.forename: D R
authors.initials: DR
authors.lastname: Barneche
authors.affiliation: IRD (Institut de Recherche pour le Développement), UR-CoRéUs, Laboratoire Arago, Banyuls/mer BP 44, 66651, France CESAB-FRB, Immeuble Henri Poincaré, Domaine du Petit Arbois, Aix-en-Provence cedex 3 13857, France.
authors.forename: M
authors.initials: M
authors.lastname: Kulbicki
authors.affiliation: Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina 88010-970, Brazil.
authors.forename: S R
authors.initials: SR
authors.lastname: Floeter
authors.affiliation: Pristine Seas-National Geographic, Washington, DC 20036, USA Fisheries Ecology Research Lab, Department of Biology, University of Hawaii, Honolulu, HI 96822, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Friedlander
authors.affiliation: Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia.
authors.forename: A P
authors.initials: AP
authors.lastname: Allen
mesh_terms: D000818:Animals; D044822:Biodiversity; D057894:Coral Reefs; D004734:Energy Metabolism / Q000502:physiology*; D005399:Fishes / Q000145:classification / Q000502:physiology*; D008954:Models, Biological; D011156:Population Density
keywords: ecosystem function; energetic equivalence; evenness; food web; metabolic theory of ecology; trophic efficiency