How do pollinator visitation rate and seed set relate to species’ floral traits and community context?
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Differences among plant species in visitation rate and seed set within a community may be explained both by the species’ floral traits and the community context. Additionally, the importance of species’ floral traits vs. community context on visitation rate and seed set may vary among communities. In communities where the pollinator-to-flower ratio is low, floral traits may be more important than community context, as pollinators may have the opportunity to be choosier when visiting plant species. In this study we investigated whether species’ floral traits (flower shape, size and number, and flowering duration) and community context (conspecific and heterospecific flower density, and pollinator abundance) could explain among-species variation in visitation rate and seed set. For this, we used data on 47 plant species from two Norwegian plant communities differing in pollinator-to-flower ratio. Differences among species in visitation rate and seed set within a community could be explained by similar variables as those explaining visitation rate and seed set within species. As expected, we found floral traits to be more important than community context in the community with a lower pollinator-to-flower ratio; whereas in the community with a higher pollinator-to-flower ratio, community context played a bigger role. Our study gives significant insights into the relative importance of floral traits on species’ visitation rate and seed set, and contributes to our understanding of the role of the community context on the fitness of plant species.
KeywordsConspecific flower density Display traits Heterospecific flower density Inter-specific comparison Pollinator abundance
We thank Paul Aakerøy, Amparo Castillo, Astrid Haavik, Manuel Hidalgo, Kristian Kyed, Rebekka Lundgren, Kirsten Marthinsen, Antón Pérez, Martín Piazzon, Anna Karina Schmidt, Mari Steinert, Siril Stenerud, Jorum Vallestad, Hartvig Velund, Silje Wang, Torstein Wilmot, and Magnus Øye for their invaluable help in the field and the lab. We are also very grateful to Asier R. Larrinaga and Martin Piazzon for their statistical advice and to Amanda M. Dorsett for language editing. This study was supported by the project 170532/V40 financed by the Norwegian Research Council. During the writing of this manuscript A. L. was supported by a Juan de la Cierva contract (Spanish Ministry of Economy and Competitiveness). The sampling complies with the current laws of the country (Norway) where it was performed.
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