High Invasive Pollen Transfer, Yet Low Deposition on Native Stigmas in a Carpobrotus-invaded Community

† Background and Aims Invasive plants are potential agents of disruption in plant – pollinator interactions. They may affect pollinator visitation rates to native plants and modify the plant – pollinator interaction network. However, there is little information about the extent to which invasive pol...

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Detalles Bibliográficos
Autores: Bartomeus, Ignasi, Bosch, Jordi, Vilà, Montserrat
Tipo de recurso: artículo
Fecha de publicación:2008
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/54752
Acceso en línea:http://hdl.handle.net/10261/54752
Access Level:acceso abierto
Palabra clave:Alien plants
Carpobrotus aff. acinaciformis
Competition for pollinators
invasion
Mediterranean shrubland
plant-pollinator network
pollen loads
pollinator visits
stigma
Descripción
Sumario:† Background and Aims Invasive plants are potential agents of disruption in plant – pollinator interactions. They may affect pollinator visitation rates to native plants and modify the plant – pollinator interaction network. However, there is little information about the extent to which invasive pollen is incorporated into the pollination network and about the rates of invasive pollen deposition on the stigmas of native plants. † Methods The degree of pollinator sharing between the invasive plant Carpobrotus affine acinaciformis and the main co-flowering native plants was tested in a Mediterranean coastal shrubland. Pollen loads were identified from the bodies of the ten most common pollinator species and stigmatic pollen deposition in the five most common native plant species. † Key Results It was found that pollinators visited Carpobrotus extensively. Seventy-three per cent of pollinator specimens collected on native plants carried Carpobrotus pollen. On average 23 % of the pollen on the bodies of pollinators visiting native plants was Carpobrotus. However, most of the pollen found on the body of pollinators belonged to the species on which they were collected. Similarly, most pollen on native plant stigmas was conspecific. Invasive pollen was present on native plant stigmas, but in low quantity. † Conclusions Carpobrotus is highly integrated in the pollen transport network. However, the plant-pollination network in the invaded community seems to be sufficiently robust to withstand the impacts of the presence of alien pollen on native plant pollination, as shown by the low levels of heterospecific pollen deposition on native stigmas. Several mechanisms are discussed for the low invasive pollen deposition on native stigmas.