title: Community fluctuations and local extinction in a planktonic food web.
abstract: Determining statistical patterns irrespective of interacting agents (i.e. macroecology) is useful to explore the mechanisms driving population fluctuations and extinctions in natural food webs. Here, we tested four predictions of a neutral model on the distribution of community fluctuations (CF) and the distributions of persistence times (APT). Novel predictions for the food web were generated by combining (1) body size-density scaling, (2) Taylor's law and (3) low efficiency of trophic transference. Predictions were evaluated on an exceptional data set of plankton with 15 years of weekly samples encompassing c. 250 planktonic species from three trophic levels, sampled in the western English Channel. Highly symmetric non-Gaussian distributions of CF support zero-sum dynamics. Variability in CF decreased while a change from an exponential to a power law distribution of APT from basal to upper trophic positions was detected. Results suggest a predictable but profound effect of trophic position on fluctuations and extinction in natural communities.
authors.affiliation: Universidad de la República, Centro Universitario Regional Este, Rocha-Maldonado, Uruguay.
authors.forename: A M
authors.initials: AM
authors.lastname: Segura
authors.affiliation: Universidad de la República, Centro Universitario Regional Este, Rocha-Maldonado, Uruguay.|Universidad de la República, Facultad de Ciencias, Montevideo, Uruguay.
authors.forename: D
authors.initials: D
authors.lastname: Calliari
authors.affiliation: Universidad de la República, Physics Institute, Complex Systems Group, Montevideo, Uruguay.|Electrical and Computer Systems Engineering, School of Engineering, Monash University, Bandar Sunway, 47500, Malaysia.
authors.forename: B L
authors.initials: BL
authors.lastname: Lan
authors.affiliation: Universidad de la República, Physics Institute, Complex Systems Group, Montevideo, Uruguay.
authors.forename: H
authors.initials: H
authors.lastname: Fort
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth PL1 3DH, UK.
authors.forename: C E
authors.initials: CE
authors.lastname: Widdicombe
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth PL1 3DH, UK.|Institut für Hydrobiologie und Fischereiwissenschaft, Universität Hamburg, Hamburg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Harmer
authors.affiliation: Universidad de la República, Centro Universitario Regional Este, Rocha-Maldonado, Uruguay.|Universidad de la República, Facultad de Ciencias, Montevideo, Uruguay.
authors.forename: M
authors.initials: M
authors.lastname: Arim
mesh_terms: D004739:England; D053476:Extinction, Biological; D020387:Food Chain; D008954:Models, Biological; D009792:Oceans and Seas; D010933:Plankton / Q000502:physiology*; D011157:Population Dynamics
keywords: English Channel; Station L4; fluctuations; food web; macroecology; plankton