Extrafloral nectar fuels ant life in deserts

ADRIANA ARANDA-RICKERT; PATRICIA DIEZ; BRIGITTE MARAZZI

AoB Plants

Editorial Board

Lugar: Oxford; Año: 2014 vol. 6 p. 1 - 14

2041-2851

Interactions mediated by extrafloral nectar (EFN)-bearing plants that reward ants with a sweet liquid secretion are well documented in temperate and tropical habitats. However, their distribution and abundance in deserts are poorly known. In this study, we test the predictions that biotic interactions between EFN plants and ants are abundant and common also in arid communities and that EFNs are only functional when new vegetative and reproductive structures are developing. In a seasonal desert of northwestern Argentina we surveyed the richness and phenology of EFN plants and their associated ants and examined patterns in ant?plant interaction networks. We found that 25 ant species and 11 EFN-bearing plant species were related into 96 pairs of associations. Plants bearing EFNs were abundant, representing ca. 19% of the species encountered in transects and 24% of the plant cover. Most ant species sampled (ca. 77 %) fed on EF nectar. Interactions showed a marked seasonal pattern: EFN secretion was directly related to plant phenology and correlated with the time of highest ant ground activity. Our results reveal that EFN-mediated interactions are ecologically relevant components of deserts, and that EFN-bearing plants are crucial for the survival of desert ant communities.