Lowering the density: ants associated with the myrmecophyte diminish the establishment of epiphytes.

Ants benefit myrmecophytic plants by two main activities defending them from herbivores and offering nutrients. Ants' territorial defence behaviour also benefits their myrmecophytic plants; in the case of trees, this behaviour includes eliminating structural parasites (epiphytes and lianas). These benefits could also occur with myrmecophytic epiphytes by decreasing the abundance of competing epiphytes. In two subunits of a tropical dry forest in the centre of Mexico, we (i) recorded the diversity of ants associated with the myrmecophyte , and experimentally tested: (ii) the effect of the ants associated with the myrmecophyte in the removal of its seeds and the seeds of other sympatric non-myrmecophyte species of ; and (iii) if seed remotion by ants corresponds with epiphyte load in the preferred () and limiting phorophyte species (. , and ). In five trees per species, we tied seed batches of , . , . and . . One seed batch was close, and the other far away from a . with active ants. Between forest subunits, ant richness was similar, but diversity and evenness differed. Ants diminish seed establishment of all the species; this effect is stronger in the forest subunit with a large ant diversity, maybe because of ant competition. Seed remotion by ants is independent of phorophyte species identity. Although ants can provide benefits to . , they also could be lowering their abundance.