The assembly and importance of a novel ecosystem: the ant community of coffee farms in Puerto Rico

Agricultural ecosystems are, by their very nature novel, and, by definition, the more general biodiversity associated with them must likewise constitute a novel community. Here we examine the community of arboreally foraging ants in the coffee agroecosystem of Puerto Rico.  We surveyed 20 coffee plants in 25 farms three times in a period of one year. We also conducted a more spatially explicit sampling in two of the farms and conducted a species interaction study between the two most abundant species, Wasmannia auropunctata and Solenopsis invicta in the laboratory. We find that the majority of the most common species are well-known invasive ants and that there is a highly variable pattern of dominance that varies considerably over the main coffee producing region of Puerto Rico, suggesting an unusual modality of community structure. The distribution pattern of the two most common species, W. auropunctata and S. invicta, suggests strong competitive exclusion. However, they also have oppo...