Are There Edge Effects on the Genetic Diversity of the Trap-Jaw Ant Odontomachus chelifer (Formicidae: Ponerinae) in a Neotropical Savanna Fragment? A First Assessment.

Habitat fragmentation is considered an important threat to biodiversity, increasing species exposure to edge effects. The Brazilian Cerrado savanna is considered a biodiversity hotspot and has been converted to small, isolated fragments due to human activities. Ant communities and colony survivorship are known to be affected by edge effects in Cerrado, but to date there is no information on the genetic diversity of ant colonies at the edge of fragmented areas.

ATLANTIC ANTS: a data set of ants in Atlantic Forests of South America.

Ants, an ecologically successful and numerically dominant group of animals, play key ecological roles as soil engineers, predators, nutrient recyclers, and regulators of plant growth and reproduction in most terrestrial ecosystems. Further, ants are widely used as bioindicators of the ecological impact of land use. We gathered information of ant species in the Atlantic Forest of South America.

Distinctive seed dispersal and seed bank patterns of invasive African grasses favour their invasion in a neotropical savanna.

High propagule availability compared to native species is often critical to invasion success, but it is unclear if this has contributed to invasions by African grasses in Neotropical savannas. We compared patterns of occurrence in the vegetation, seed rain and seed bank among African and native grasses in Cerrado sites in southeastern Brazil. In grasslands and savannas, we obtained the abundance of grasses in the vegetation, in the seed rain (monthly for one year) and in the seed bank (rainy and dry season), and assessed seed limitation and relationships among compartments.

Bird and ant synergy increases the seed dispersal effectiveness of an ornithochoric shrub.

Seed dispersal may involve different vectors of dispersal in two or more sequential phases (i.e., diplochory).

The relevance of ants as seed rescuers of a primarily bird-dispersed tree in the Neotropical cerrado savanna.

The scale at which seed dispersal operates has many implications for the spatial patterns of plant recruitment and diversity. We investigated the effect of short- (ants) and long-distance (birds) seed dispersal of the fleshy-fruited melastome, Miconia rubiginosa, in the Brazilian savanna. We estimated the contribution of dispersal vectors to the removal of the fruit crop from the canopy (birds), and once seeds have reached the cerrado floor (ants) over two fruiting seasons.