, Volume 167, Issue 4, pp 1027–1039 | Cite as

What are the consequences of ant–seed interactions on the abundance of two dry-fruited shrubs in a Mediterranean scrub?

  • Xavier ArnanEmail author
  • A. Rodrigo
  • J. Retana
Plant-Animal Interactions - Original Paper


Strong interactions between dry-fruited shrubs and seed-harvesting ants are expected in early successional scrubs, where both groups have a major presence. We have analysed the implications of the seed characteristics of two dry-fruited shrub species (Coronilla minima and Dorycnium pentaphyllum) on seed predation and dispersal mediated by harvester ants and the consequences of these processes on spatio-temporal patterns of plant abundance in a heterogeneous environment. We found that large C. minima seeds were collected much more (39%) than small D. pentaphyllum seeds (2%). However, not all of the removed seeds of these plant species were consumed, and 12.8% of the seeds were lost along the trails, which increased dispersal distances compared with abiotic dispersal alone. Seed dropping occurred among all microhabitats of the two plant species, but especially in open microhabitats, which are the most suitable ones for plant establishment. The two plant species increased their presence in the study area during the study period: C. minima in open microhabitats and D. pentaphyllum in high vegetation. The large size of C. minima seeds probably limited the primary seed dispersal of this species, but may have allowed strong interaction with ants. Thus, seed dispersal by ants resulted in C. minima seeds reaching more suitable microhabitats by means of increasing dispersal distance and redistribution among microhabitats. In contrast, the smaller size of D. pentaphyllum seeds arguably allows abiotic seed dispersal over longer distances and colonization of all types of microhabitats, although it probably also limits their interaction with ants and, consequently, their redistribution in suitable microhabitats. We suggest that dyszoochory could contribute to the success of plant species with different seed characteristics in scrub habitats where seeds are abundantly collected by seed-harvesting ants.


Microhabitat suitability Plant recruitment Seed dispersal Seed predation Seed-harvesting ants 



We are very grateful to Helena Barril for field assistance and Jacqueline Minett for the correction of the English. This research was partly funded by CICYT project REN2001-2500/GLO, by the CONSOLIDER INGENIO project CSD 2008-0040 and by the Departament d’Universitats, Recerca i Societat de la Generalitat de Catalunya grant 2002 FI 00095 to X. Arnan. All experiments comply with the Spanish current laws.


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© Springer-Verlag 2011

Authors and Affiliations

  1. 1.Unitat d’Ecologia i CREAF, Facultat de BiociènciesUniversitat Autònoma de BarcelonaBellaterra, BarcelonaSpain

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