In tropical rainforests, the ant community can be divided into ground and arboreal faunas. Here we report a thorough sampling of the arboreal ant fauna of La Selva Biological Station, a Neotropical rainforest site. Forty-five canopy fogging samples were centered around large trees. Individual samples harbored an average of 35 ant species, with up to 55 species in a single sample. The fogging samples yielded 163 observed species total, out of a statistically estimated 199 species. We found no relationship between within-sample ant richness and focal tree species, nor were the ant faunas of nearby trees more similar to each other than the faunas of widely spaced trees. Species density was high and beta diversity was low: a single column of vegetation typically harbors at least a fifth of the entire arboreal ant fauna. Considering the entire fauna, based on 23,326 species occurrence records using a wide variety of collecting methods, 182 of 539 observed species (196 of 605, estimated statistically) were entirely arboreal. The arboreal ant fauna is thus about a third of the total La Selva ant fauna, a robust result because inventory completeness was similar for ground and arboreal ants. The taxonomic history of discovery of the species that make up the La Selva fauna reveals no disproportionately large pool of undiscovered ant species in the canopy. The "last biotic frontier" for tropical ants has been the rotten wood, leaf litter, and soil of the forest floor.

canopy fogging

Three datasets are provided that are the basis of analyses in "The arboreal ants of a Neotropical rainforest show high species density and comprise one third of the ant fauna," in Biotropica. One dataset is ant species occurrences in a set of canopy fogging samples. One dataset is individual specimen records for the entire La Selva ant fauna. One dataset is a species list for the entire fauna, with information on frequency and microhabitat (mostly ground vs. canopy).