RESUMEN
Animal-plant interactions are important for the recovery of diversity and processes in secondary forests, which increasingly dominate the tropical landscape. We used a combination of observational and experimental approaches to study the interactions of ants with diaspores across a successional gradient of forests in Southern Brazil, from August 2007 to April 2008. In addition to diaspore removal rates, we assessed the species richness, diversity and behaviour of ants interacting with diaspores, in three replicated sites of four successional stages of forests. We recorded 22 ant species interacting with diaspores (an estimated 15% of the total species pool in the region). Species richness and diversity did not differ among successional stages but the behaviour of ants towards diaspores changed with the age of secondary forests. In old successional stages the removal of entire diaspores was more common than in young successional stages of forests. Concordantly, diaspore removal rates were lowest in the youngest successional stage of secondary forests and increased with the age of forests. These results indicate that ant-diaspore interactions in secondary forests are disturbed and lower removal rates in secondary forests are likely to constrain the recruitment of plant populations during secondary succession. Rev. Biol. Trop. 60 (2): 933-942. Epub 2012 June 01.
Las interacciones entre animales y plantas son importantes para la recuperación de la diversidad y los procesos en los bosques secundarios, los cuales cada vez más tienden a dominar el paisaje tropical. Nosotros utilizamos una combinación de métodos experimentales y observaciones para estudiar las interacciones entre hormigas y diásporas a través de un gradiente de sucesión en los bosques del sur de Brasil, entre agosto 2007 y abril 2008. Además de las tasas de eliminación de diásporas, evaluamos la riqueza de especies, la diversidad y el comportamiento de las hormigas que interactúan con las diásporas, con tres repeticiones por sitio de cuatro estadios de sucesión del bosque. Se registraron 22 especies de hormigas que interactúan con diásporas (se estima un 15% del total de especies en la región). La riqueza y diversidad de especies no varió entre las etapas de sucesión, pero el comportamiento de las hormigas hacia las diásporas cambio con la edad de los bosques secundarios. En las etapas sucesionales avanzadas del bosque la eliminación de diásporas fue más común que en las etapas tempranas. En concordancia, las tasas de eliminación de diásporas fueron menores en la etapa más temprana de la sucesión de bosques secundarios y aumenta con la edad de los mismos. Estos resultados indican que las interacciones hormigasdiásporas en los bosques secundarios son alteradas y las menores tasas de extracción en los bosques secundarios es probable que limiten el reclutamiento de las poblaciones de plantas durante la sucesión secundaria.
Asunto(s)
Animales , Hormigas/fisiología , Biodiversidad , Conducta Animal/fisiología , Árboles , Hormigas/clasificación , Brasil , Ecosistema , Dinámica PoblacionalRESUMEN
Animal-plant interactions are important for the recovery of diversity and processes in secondary forests, which increasingly dominate the tropical landscape. We used a combination of observational and experimental approaches to study the interactions of ants with diaspores across a successional gradient of forests in Southern Brazil, from August 2007 to April 2008. In addition to diaspore removal rates, we assessed the species richness, diversity and behaviour of ants interacting with diaspores, in three replicated sites of four successional stages of forests. We recorded 22 ant species interacting with diaspores (an estimated 15% of the total species pool in the region). Species richness and diversity did not differ among successional stages but the behaviour of ants towards diaspores changed with the age of secondary forests. In old successional stages the removal of entire diaspores was more common than in young successional stages of forests. Concordantly, diaspore removal rates were lowest in the youngest successional stage of secondary forests and increased with the age of forests. These results indicate that ant-diaspore interactions in secondary forests are disturbed and lower removal rates in secondary forests are likely to constrain the recruitment of plant populations during secondary succession.