Diversity and structure of the arthropod fauna within three canopy epiphyte species in central Panama

The arthropod fauna inhabiting 90 individuals of three different species of epiphyte was investigated in the moist lowland forest of the Barro Colorado National Monument in Panama. In total, 3694 arthropods belonging to 89 morphospecies and 19 orders were collected. While arthropod abundance was primarily a function of host plant biomass irrespective of epiphyte species, there were pronounced differences in species richness, species composition and guild structure of the arthropod faunas of the three epiphyte species. Although all study plants were growing in close proximity on the same host tree species, there was remarkably little overlap in the species assemblages across epiphyte taxa. The inhabitant species also differed dramatically in their ecological functions, as feeding guild and hunting guild analyses indicated. The influence of plant size, structure and impounded leaf litter on arthropod diversity is discussed. We conclude that epiphytes are microhabitats for a diverse and numerous fauna, and that different species of epiphytes foster both taxonomically and ecologically very distinct arthropod assemblages.