title: Genotypic variation in foundation species generates network structure that may drive community dynamics and evolution.
abstract: Although genetics in a single species is known to impact whole communities, little is known about how genetic variation influences species interaction networks in complex ecosystems. Here, we examine the interactions in a community of arthropod species on replicated genotypes (clones) of a foundation tree species, Populus angustifolia James (narrowleaf cottonwood), in a long-term, common garden experiment using a bipartite "genotype-species" network perspective. We combine this empirical work with a simulation experiment designed to further investigate how variation among individual tree genotypes can impact network structure. Three findings emerged: (1) the empirical "genotype-species network" exhibited significant network structure with modularity being greater than the highly conservative null model; (2) as would be expected given a modular network structure, the empirical network displayed significant positive arthropod co-occurrence patterns; and (3) furthermore, the simulations of "genotype-species" networks displayed variation in network structure, with modularity in particular clearly increasing, as genotypic variation increased. These results support the conclusion that genetic variation in a single species contributes to the structure of ecological interaction networks, which could influence eco-ogical dynamics (e.g., assembly and stability) and evolution in a community context.
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Lau
authors.forename: Arthur R
authors.initials: AR
authors.lastname: Keith
authors.forename: Stuart R
authors.initials: SR
authors.lastname: Borrett
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Shuster
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Whitham
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003198:Computer Simulation; D020387:Food Chain; D014644:Genetic Variation; D005838:Genotype; D007313:Insecta / Q000235:genetics*; D008954:Models, Biological; D032107:Populus / Q000235:genetics*