title: Competition for pollinators and intra-communal spectral dissimilarity of flowers.
abstract: Competition for pollinators occurs when, in a community of flowering plants, several simultaneously flowering plant species depend on the same pollinator. Competition for pollinators increases interspecific pollen transfer rates, thereby reducing the number of viable offspring. In order to decrease interspecific pollen transfer, plant species can distinguish themselves from competitors by having a divergent phenotype. Floral colour is an important signalling cue to attract potential pollinators and thus a major aspect of the flower phenotype. In this study, we analysed the amount of spectral dissimilarity of flowers among pollinator-competing plants in a Dutch nature reserve. We expected pollinator-competing plants to exhibit more spectral dissimilarity than non-competing plants. Using flower visitation data of 2 years, we determined the amount of competition for pollinators by different plant species. Plant species that were visited by the same pollinator were considered specialist and competing for that pollinator, whereas plant species visited by a broad array of pollinators were considered non-competing generalists. We used principal components analysis to quantify floral reflectance, and found evidence for enhanced spectral dissimilarity among plant species within specialist pollinator guilds (i.e. groups of plant species competing for the same pollinator). This is the first study that examined intra-communal dissimilarity in floral reflectance with a focus on the pollination system.
authors.affiliation: Plant Physiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.|Computational Physics, Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands.
authors.forename: C J
authors.initials: CJ
authors.lastname: van der Kooi
authors.affiliation: Theoretical Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.
authors.forename: I
authors.initials: I
authors.lastname: Pen
authors.affiliation: Plant Physiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Staal
authors.affiliation: Computational Physics, Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands.
authors.forename: D G
authors.initials: DG
authors.lastname: Stavenga
authors.affiliation: Plant Physiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.
authors.forename: J T M
authors.initials: JT
authors.lastname: Elzenga
mesh_terms: D000818:Animals; D001516:Bees / Q000502:physiology; D035264:Flowers / Q000737:chemistry / Q000502:physiology*; D009426:Netherlands; D054817:Pollination / Q000502:physiology*; D025341:Principal Component Analysis; D013045:Species Specificity
keywords: Biotic interactions; flower colouration; plant-pollinator signalling; principal components analysis; reproductive character displacement