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.

How to colour a flower: on the optical principles of flower coloration

“…The plant kingdom encompasses a bewildering array of differently coloured flowers [3,6,10,13,27], with variations in anatomy, pigments, and pigment localizations, but how these differences contribute to the overall visual signal of flowers is largely unknown. Absorption by pigments occurs in the (ultra)-violet, short-, and medium-wavelength ranges, but not in the long-wavelength range, i.e.…”

“…Figure 2 presents the spectra of four differentcoloured exemplary flowers. Flowers that appear white to the human eye always had a low UV reflectance (figure 1a; electronic supplementary material, figure S2; see also [10,27]). The blue, yellow, and red flowers yielded a high reflectance in the short-, medium-, and long-wavelength ranges, respectively, and occasionally featured an additional high ultraviolet (UV) reflectance (figure 1; electronic supplementary material, figure S1).…”

Estimating Total Phenolics in Taraxacum officinale (L.) Extracts

“…The flower heads are ligulate and bisexual. The leaves are obovate in shape with strident or gentle teeth [10].…”

Pollination biology from micro‐morphological adaptations to community ecology of plant–pollinator interactions

“…() focused on the UV reflection patterns in relation to the perception of functional groups of specific pollinators, van der Kooi et al . () offer a fresh look at intra‐community spectral characteristics of plants in a nature reserve in The Netherlands. These authors present an original study that examined whether plants that compete for pollinators are likely to experience divergent selection by pollinators on their floral phenotype (here, the floral reflectance).…”