Intra-specific downsizing of frugivores affects seed germination of fleshyfruited plant species

• Autores: Pérez Méndez, Néstor; Rodríguez, Airam; Nogales, Manuel
• Año de publicación: 2017
• Idioma: español castellano
• Tipo de recurso: artículo
• Materia: Ciencias Biológicas; Ciencias Ambientales y de la Tierra; Defaunation; Saurochory; Pest Control; Seed Dispersal; Plant Recruitment; Canary Islands; Ciencias Biológicas; Ciencias Ambientales y de la Tierra
• Institución: Universidad Nacional de Río Negro

Fil: Pérez Méndez, Néstor. IRTA-Amposta Spain. Carretera de Balada. Amposta. Tarragona; España.
Fil: Pérez Méndez, Néstor. Universidad Nacional de Río Negro. Sede Andina. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural (IRNAD); Argentina.
Fil: Rodríguez, Airam. Department of Evolutionary Ecology, Estación Biológica de Doñana (EBD-CSIC). Sevilla; España.
Fil: Nogales, Manuel. Island Ecology and Evolution Research Group, Instituto de Productos Naturales y Agrobiología (IPNA-CSIC); España.
The loss of largest-bodied individuals within species of frugivorous animals is one of the major consequences of defaunation. The gradual disappearance of large-bodied frugivores is expected to entail a parallel deterioration in seed dispersal functionality if the remaining smaller-sized individuals are not so effective as seed dispersers. While the multiple impacts of the extinction of large bodied species have been relatively well studied, the impact of intraspecific downsizing (i.e. the extinction of large individuals within species) on seed dispersal has rarely been evaluated. Here we experimentally assessed the impact of body-size reduction in the frugivorous lizard Gallotia galloti (Lacertidae), an endemic species of the Canary Islands, on the seed germination patterns of two fleshy-fruited plant species (Rubia fruticosa and Withania aristata). Seed germination curves and the proportions of germinated seeds were compared for both plant species after being defecated by large-sized individuals and small-sized individuals. The data show that seeds of W. aristata defecated by larger-sized lizards germinated faster and in a higher percentage than those defecated by small-sized lizards, while no differences were found for R. fruticosa seeds. Our results suggest that disappearance of the largest individuals of frugivorous species may impair recruitment of some plant species by worsening seed germination. They also warn us of a potential cryptic loss of seed dispersal functionality on defaunated ecosystems, even when frugivorous species remain abundant.