What processes originate and maintain species diversity in tropical ecosystems? Both evolutionary and conservation biologists are interested in understanding the mechanisms that regulate diversity patterns, especially in groups that are considered to be hyperdiverse and groups that accomplish key ecosystem roles. For tropical ecosystems, one such group is Formicidae, and within Formicidae, the genus Pheidole. I carried out a survey on ground dwelling ants in a neotropical forest associated to Los Amigos Biological Station, located in Madre de Dios, Peru. For this survey, I used baits of protein and carbohydrates because this type of baits attract generalist ants, and because the long term objective of this research focus on species observed to strongly interact with each other for food resource. All observations and sampling were confined to 5 paired plots of 25m x 25m:  5 plots in bamboo forests and 5 plots in mixed canopy forests. Each plot was subdivided into 25 subcuadrats, that is, each plot comprise 25 baiting stations. Each baiting station was sampled at least 2 times for a total of 500 baiting events. Bait stations were monitored for ant competitive interactions and vouchers of ants were collected from each baiting event. Specimens of Pheidole were separated into morphotypes. Preliminary species identification was corroborated or corrected by Stefan Cover (Museum of Comparative Zoology, Harvard).

Results/Conclusions

Preliminary results revealed that Pheidole constitutes 42% of the specific composition in these forests: 43 Pheidole spp out of a total of 103 ant species. The average number of interacting Pheidole species in these assemblages, i.e. per plot, is 16; which is significantly higher than in temperate forests, where the number of interacting Pheidole is around 3 species.The statistical analysis of the association to habitat type by species (Indicator value of Dufrene and Lengendre), revealed that 8 species of Pheidole: P. araneoides, P ns nr dolon, P. embolopyx, P. laidlowi, P. leonina, P. ns. nr. machetula, P. zelata, y P. ns nr 11, showed a significant association to mixed canopy forests, and no Pheidole species showed a significant association to bamboo forests. Analysis of data to contrast ant assemblages abundance, as well as, to determine the role of competition in these communities is still ongoing. To my knowledge, this research is the first one in determining ant communities in Guadua spp forests.