Pogonomyrmexcunicularius as the keystone disperser of elaiosome-bearing Jatropha excisa seeds in semi-arid Argentina

Myrmecochory or seed dispersal by ants is often described as a diffuse mutualism, because many of the ant species that function as partners are considered to be similar in terms of the frequency and consequences of their interactions. In this work, we test this assumption by conducting ant community...

Descripción completa

Detalles Bibliográficos
Autores: Aranda Rickert, Adriana Marina, Fracchia, Sebastian
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2011
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/68554
Acceso en línea:http://hdl.handle.net/11336/68554
Access Level:acceso abierto
Palabra clave:Diffuse Mutualism
Euphorbiaceae
Formicidae
Hymenoptera
Keystone Species
Myrmecochory
Myrmicinae
Seed Dispersal
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:Myrmecochory or seed dispersal by ants is often described as a diffuse mutualism, because many of the ant species that function as partners are considered to be similar in terms of the frequency and consequences of their interactions. In this work, we test this assumption by conducting ant community surveys and seed removal experiments in six study sites located within a semi-arid region of northwest Argentina. At each site, we characterized the ant assemblage that interacted with the seeds of Jatropha excisa Griseb. (Euphorbiaceae), an ant-dispersed native shrub. Our results demonstrate that seed removal was dominated by one species, Pogonomyrmex cunicularius Mayr (Hymenoptera: Formicidae: Myrmicinae), which was responsible of 84% of the observed seed removal events. Although several ant species were attracted to the elaiosome-bearing seeds of J. excisa, seed removal did not depend on ant community composition (species richness and ant activity) but was significantly influenced by the abundance of P. cunicularius. Its physical, behavioral, and ecological attributes are common with other ant species that have been characterized as keystone seed dispersers in other regions of the world. Nest feeding with marked seeds revealed that once P. cunicularius ants consume the elaiosomes, seeds are left inside the nests undamaged and at an appropriate depth for emergence. Our results support the hypothesis that myrmecochory is often an unevenly diffuse mutualism (i.e., one partner species is particularly important) and that at a local scale P. cunicularius is the keystone seed disperser of J. excisa.