Removal of Nonmyrmecochorous Seeds by Ants: Role of Ants in Cattle Grasslands

Abstract

Livestock production models prevailing in Colombian Andes are simplified treeless pastures for extensive ranching, with the consequent reduction of environmental services, such as seed dispersal, due to lack of primary dispersers, scarcity of adequate sites for seedling establishment and competition with grasses. This study evaluated if, in these harsh environments, ants can promote the colonization of arboreal species through directed dispersion of seeds towards the nests. Ten seeds of each species were offered to ants in six grazing pastures. Ants removed 25% of the seeds (1827) in 48 hours. Preference for arillated and small-to-medium sized seeds, such as Pithecellobium dulce, and Guazuma ulmifolia, was observed. Cyphomyrmex major, Ectatomma ruidum, Solenopsis geminata and Atta cephalotes were the key ant species in seed removal. It was concluded that functional ant groups present in the pastures could contribute to secondary dispersion of seeds with potential for restoration.

Ants Promote Germination of the Tree Guarea guidonia by Cleaning its Seeds

“…Ants are among the common tropical dispersers, especially in ecologically degraded environments (Henao-Gallego et al, 2012). They interact with a broad variety of fruits and seeds while foraging for pulp or aril and as a result promote seed dispersal (Christianini & Oliveira, 2010;Christianini et al, 2012;Escobar-Ramírez et al, 2012;Bieber et al, 2013;Lima et al, 2013;Santana et al, 2013;Gallegos et al, 2014).…”

Can variation in seed removal patterns of Neotropical pioneer tree species be explained by local ant community composition?

“…Ripe fruits were collected from below parent trees of 12 pioneer species (Table 1). Seeds of these Neotropical pioneer tree species are not known to have elaiosomes or other ant attractants (except for Guazuma ulmifolia whose seeds produce mucilage which may be an ant attractant; Escobar-Ramírez et al, 2012). The seeds of these tree species also vary in several characteristics including defense TA B L E 1 Tree species used in the different experiments (A = aboveground, B = belowground), seed traits, and seed removal percentages (mean and standard error) per tree species (aboveground: pooled over dry and wet seasons; belowground: wet season only) for each experiment.…”

The role of herbivorous insects and pathogens in the regeneration dynamics of Guazuma ulmifolia in Panama

“…We also suspect that ants, particularly Atta spp., removed some of the seeds used in the experiment. In Colombia, several ant species, such as Atta cephalotes, are known to remove preferentially in open pastures small tree seeds including G. ulmifolia (Escobar-Ramírez et al 2012). On BCI, a high proportion of G. ulmifolia seeds are removed secondarily, presumably by ants (Ruzi et al 2017).…”