title: The role of abiotic environmental conditions and herbivory in shaping bacterial community composition in floral nectar.
abstract: Identifying the processes that drive community assembly has long been a central theme in ecology. For microorganisms, a traditional prevailing hypothesis states that "everything is everywhere, but the environment selects". Although the bacterial community in floral nectar may be affected by both atmosphere (air-borne bacteria) and animals as dispersal vectors, the environmental and geographic factors that shape microbial communities in floral nectar are unknown. We studied culturable bacterial communities in Asphodelus aestivus floral nectar and in its typical herbivorous bug Capsodes infuscatus, along an aridity gradient. Bacteria were sampled from floral nectar and bugs at four sites, spanning a geographical range of 200 km from Mediterranean to semi-arid conditions, under open and bagged flower treatments. In agreement with the niche assembly hypothesis, the differences in bacterial community compositions were explained by differences in abiotic environmental conditions. These results suggest that microbial model systems are useful for addressing macro-ecological questions. In addition, similar bacterial communities were found in the nectar and on the surface of the bugs that were documented visiting the flowers. These similarities imply that floral nectar bacteria dispersal is shaped not only by air borne bacteria and nectar consumers as previously reported, but also by visiting vectors like the mirid bugs.
authors.affiliation: Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel.
authors.forename: Michal
authors.initials: M
authors.lastname: Samuni-Blank
authors.affiliation: Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel.
authors.forename: Ido
authors.initials: I
authors.lastname: Izhaki
authors.affiliation: Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel.
authors.forename: Sivan
authors.initials: S
authors.lastname: Laviad
authors.affiliation: Department of Biology and Environment, University of Haifa at Oranim, Oranim, Tivon, Israel.
authors.forename: Avi
authors.initials: A
authors.lastname: Bar-Massada
authors.affiliation: Department of Biology and Environment, University of Haifa at Oranim, Oranim, Tivon, Israel.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Gerchman
authors.affiliation: Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel; Department of Biology and Environment, University of Haifa at Oranim, Oranim, Tivon, Israel.
authors.forename: Malka
authors.initials: M
authors.lastname: Halpern
mesh_terms: D000818:Animals; D002980:Climate; D035264:Flowers / Q000382:microbiology*; D006430:Hemiptera / Q000382:microbiology / Q000502:physiology; D060434:Herbivory; D019668:Liliaceae / Q000382:microbiology*; D064307:Microbiota; D057048:Plant Nectar
chemical_list: D057048:Plant Nectar