Barneche D. R. auteur aut IRD Kulbicki Michel auteur aut IRD Floeter S. R. auteur aut IRD Friedlander A. M. auteur aut IRD Allen A. P. auteur aut IRD text journalArticle eng text/pdf born digital access 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. specialized energetic equivalence ecosystem function metabolic theory of ecology food web trophic efficiency evenness MONDE 036 283 1823 art. 20152186 [8 p.] 2016 0962-8452 https://www.documentation.ird.fr/hor/fdi:010066148 10.1098/rspb.2015.2186 0962-8452 [F B010066148] https://www.documentation.ird.fr/hor/fdi:010066148 https://www.documentation.ird.fr/intranet/publi/2016/02/010066148.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2016-02-26 2017-08-23 fdi:010066148 fre