Do visual traits honestly signal floral rewards at community level?

The high variability observed in floral traits has been interpreted as resulting from the adaptation of plants to pollinators, as the latter present innate preferences for specific floral traits and impose selection over them. However, some pollinators such as bees can learn to associate floral sign...

Descripción completa

Detalles Bibliográficos
Autores: Ortiz Ballesteros, Pedro Luis, Fernández Díaz, Pilar, Pareja Bonilla, Daniel, Escudero Lirio, Marcial, Arista Palmero, Montserrat
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2021
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/152968
Acceso en línea:https://hdl.handle.net/11441/152968
https://doi.org/10.1111/1365-2435.13709
Access Level:acceso abierto
Palabra clave:Flower colour
Flower size
Flower symmetry
Mediterranean
Nectar
Phylogenetic signal
Plant–pollinator interaction
Descripción
Sumario:The high variability observed in floral traits has been interpreted as resulting from the adaptation of plants to pollinators, as the latter present innate preferences for specific floral traits and impose selection over them. However, some pollinators such as bees can learn to associate floral signals with rewards, thus increasing floral constancy on more rewarding flowers. The integration of all these rewards and cues is markedly important at community level, where co-flowering species compete for pollinators. In order to verify the honesty of the above-mentioned signals, we examined the association between floral visual signals (size, colour, symmetry and floral display) and rewards (pollen and nectar) for 98 species in a Mediterranean community. The associations between floral traits were analysed considering the phylogenetic relationship between the different species. Flower colour, size, pollen volume or amount of sucrose exhibited no phylogenetic signal, which suggests an adaptive evolution in response to different conditions in the pollinator community. Flower size was seen to constitute the most honest signal for pollinators, as this was significantly associated with quantities of pollen and nectar. In contrast, nectar concentration was observed to be positively associated with chromatic contrast. We detected no relationship between flower shape and rewards, on the one hand, nor between flower display and rewards, on the other. Our study unequivocally demonstrates the correlation between rewards and the visual signals perceived by bees, the most effective pollinators in the Mediterranean Basin. In the community studied, bees employed flower size at longer distances and chromatic contrast at shorter distances to predict rewards. The limited number of studies existing in this sense indicates that this kind of association appears to be community specific.