Introduction:

Frugivory is a pivotal ecological process for the structure and regeneration of forests. In the tropics, where the diversity of plants and frugivorous animals is high, interspecific relationships in the interaction networks are complex and need study.

Objective:

To identify ecologically important plant species in two interaction networks, and the role of functional fruit traits in those interactions in a dry forest.

Methods:

We collected 10 fruits per plant from 10 plants of each species of interest in a Colombian dry forest, we calculated the Plant Importance Index based on the bird and mammal frugivores relevance for network structure. This relevance is directly related to the animal's potential as effective seed dispersers. We used generalized linear models to estimate the effect of fruit size, color, stratum, and type of pulp, on the index.

Results:

The most important plants are species of the genera Miconia, Ficus, Cecropia, Bursera, Casearia and Trichilia, also identified as important resources for tropical frugivores in other studies. Plants with small, red, and fleshy fruits are the best for seed dispersers. The plant importance index has a high variation; this suggests that the set of frugivore species benefited by each plant species has a differential contribution to the ecological processes derived from seed dispersal.

Conclusions:

Restoration programs for this kind of tropical dry forest should include a variety of plants, including species with small, red, and fleshy fruits.