title: The dynamics of community assembly under sudden mixing in experimental microcosms.
abstract: Landscape connectivity has been shown to alter community assembly and its consequences. Here we examine how strong, sudden changes in connectivity may affect community assembly by conducting experiments on the effects of "community mixing," situations where previously isolated communities become completely connected with consequent community reorganization. Previous theory indicates that assembly history dictates the outcome of mixing: mixing randomly assembled communities leads to a final community with random representation from the original communities, while mixing communities that were assembled via a long history of colonizations and extinctions leads to strong asymmetry, with one community dominating the other. It also predicts that asymmetry should be stronger in the presence of predators in the system. We experimentally tested and explored this theory by mixing aquatic microcosms inhabited by a complex food web of heterotrophic protists, and algae. Our results confirm the prediction that long assembly history can produce asymmetry under mixing and suggest these dynamics could be important in natural systems. However, in contrast to previous theory we also found asymmetry weaker under mixing of communities with more complex trophic structure.
authors.affiliation: Section of Integrative Biology, University of Texas at Austin, 1 University Station C0930, Austin, Texas 78712, USA. glivingston@utexas.edu
authors.forename: George
authors.initials: G
authors.lastname: Livingston
authors.affiliation: Section of Integrative Biology, University of Texas at Austin, 1 University Station C0930, Austin, Texas 78712, USA.
authors.forename: Yuexin
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2L 1Z3 Canada.
authors.forename: Jeremy W
authors.initials: JW
authors.lastname: Fox
authors.affiliation: Section of Integrative Biology, University of Texas at Austin, 1 University Station C0930, Austin, Texas 78712, USA.
authors.forename: Mathew A
authors.initials: MA
authors.lastname: Leibold
mesh_terms: D000818:Animals; D001419:Bacteria; D003198:Computer Simulation; D017753:Ecosystem; D005247:Feeding Behavior; D010944:Plants / Q000145:classification*