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Universidad de Buenos Aires (2007)

Granivoría por hormigas del género Pogonomyrmex en el Monte Central : consumo de semillas e impacto sobre el banco de suelo

Pirk, Gabriela Inés

Titre : Granivoría por hormigas del género Pogonomyrmex en el Monte Central : consumo de semillas e impacto sobre el banco de suelo

Seed harvesting by ants of the genus pogonomyrmex in the Central Monte Desert : seed consumption and impact on the soil seed bandk

Auteur : Pirk, Gabriela Inés

Université de soutenance : Universidad de Buenos Aires

Grade : Doctor de la Universidad de Buenos Aires en el área de Ciencias Biológicas 2007

Résumé
The trophic ecology of Pogonomyrmex rastratus, P. pronotalis and P. inermis was studied in order to determine the role they play as seed consumers in the central Monte desert. Grass seeds prevailed in their diet. Grass seed abundance in the environment influenced diet patterns : the three species carried a greater proportion of vegetative plant structures and invertebrates, P. rastratus and P. pronotalis consumed other types of seeds and the activity of P. inermis was lower when grass seed abundance was low. Grass seeds were also highly preferred in seed offer experiments showing that the diet of these species reflects their preferences. Seed size proved important in determining preference and diet patterns. Seed harvesting by P. rastratus and P. inermis affected seed abundance of the most consumed species close to the nest, at least from summer to the beginning of autumn. The effect of seed abundance on ant foraging behaviour ("bottom-up") was more important in spring, whereas the effect of ant consumption on seed abundance ("top-down") prevailed during the summer and the beginning of autumn. This study shows that Pogonomyrmex species are important seed consumers in the central Monte desert.

Mots clés : ALIMENTACION SELECTIVA ; BANCO DE SEMILLAS ; ECOLOGIA DE COMUNIDADES ; GRANIVORIA ; HORMIGA ; POGONOMYRMEX INERMIS ; POGONOMYRMEX PRONOTALIS ; POGONOMYRMEX RASTRATUS ; SEMILLA ; PREFERENCIAS ALIMENTICIAS ; ANT ; COMMUNITY ECOLOGY ; FEEDING PREFERENCES ; GRANIVORY ; POGONOMYRMEX INERMIS ; POGONOMYRMEX PRONOTALIS ; POGONOMYRMEX RASTRATUS ; SEED ; SEED BANK ; SELECTIVE FEEDING

Présentation (Biblioteca Digital)

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Page publiée le 24 février 2016, mise à jour le 3 juillet 2017