title: Niches versus neutrality: uncovering the drivers of diversity in a species-rich community.
abstract: Ecological models suggest that high diversity can be generated by purely niche-based, purely neutral or by a mixture of niche-based and neutral ecological processes. Here, we compare the degree to which four contrasting hypotheses for coexistence, ranging from niche-based to neutral, explain species richness along a body mass niche axis. We derive predictions from these hypotheses and confront them with species body-mass patterns in a highly sampled marine phytoplankton community. We find that these patterns are consistent only with a mechanism that combines niche and neutral processes, such as the emergent neutrality mechanism. In this work, we provide the first empirical evidence that a niche-neutral model can explain niche space occupancy pattern in a natural species-rich community. We suggest this class of model may be a useful hypothesis for the generation and maintenance of species diversity in other size-structured communities.
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Alfred Denny Building, Western Bank, Sheffield S10 2TN, UK. r.vergnon@sheffield.ac.uk
authors.forename: Remi
authors.initials: R
authors.lastname: Vergnon
authors.forename: Nicholas K
authors.initials: NK
authors.lastname: Dulvy
authors.forename: Robert P
authors.initials: RP
authors.lastname: Freckleton
mesh_terms: D044822:Biodiversity; D018533:Biomass; D004777:Environment; D008954:Models, Biological; D010839:Phytoplankton / Q000254:growth & development / Q000502:physiology*