title: Landscape-scale spatial abundance distributions discriminate core from random components of boreal lake bacterioplankton.
abstract: Aquatic bacterial communities harbour thousands of coexisting taxa. To meet the challenge of discriminating between a 'core' and a sporadically occurring 'random' component of these communities, we explored the spatial abundance distribution of individual bacterioplankton taxa across 198 boreal lakes and their associated fluvial networks (188 rivers). We found that all taxa could be grouped into four distinct categories based on model statistical distributions (normal like, bimodal, logistic and lognormal). The distribution patterns across lakes and their associated river networks showed that lake communities are composed of a core of taxa whose distribution appears to be linked to in-lake environmental sorting (normal-like and bimodal categories), and a large fraction of mostly rare bacteria (94% of all taxa) whose presence appears to be largely random and linked to downstream transport in aquatic networks (logistic and lognormal categories). These rare taxa are thus likely to reflect species sorting at upstream locations, providing a perspective of the conditions prevailing in entire aquatic networks rather than only in lakes.
authors.affiliation: Groupe de Recherche Interuniversitaire en Limnologie et en Environnement Aquatique (GRIL), Département des Sciences Biologiques, Université du Québec à Montréal, Case Postale 8888, succursale Centre-Ville, Montréal, QC, H3C 3P8, Canada.|Escuela de Microbiología, Universidad de Antioquia (UdeA), Ciudad Universitaria, Calle 67 No 53-108, Medellín, Colombia.
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Niño-García
authors.affiliation: Groupe de Recherche Interuniversitaire en Limnologie et en Environnement Aquatique (GRIL), Département des Sciences Biologiques, Université du Québec à Montréal, Case Postale 8888, succursale Centre-Ville, Montréal, QC, H3C 3P8, Canada.|Institut de Ciències del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, Barcelona, 08003, Spain.
authors.forename: Clara
authors.initials: C
authors.lastname: Ruiz-González
authors.affiliation: Groupe de Recherche Interuniversitaire en Limnologie et en Environnement Aquatique (GRIL), Département des Sciences Biologiques, Université du Québec à Montréal, Case Postale 8888, succursale Centre-Ville, Montréal, QC, H3C 3P8, Canada.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Del Giorgio
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D017753:Ecosystem; D004784:Environmental Monitoring; D060106:Lakes; D010933:Plankton / Q000145:classification* / Q000382:microbiology* / Q000502:physiology; D045483:Rivers; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial
keywords: Aquatic bacterial communities; boreal lakes; environmental sorting; hydrologic network; mass effects; rare biosphere; recruitment