Mites in the mist: how unique is a rainforest canopy-knockdown fauna?

We intensively sampled the parasitiform mite faunas of three subtropical rainforest canopy habitats (leaves, bark, hanging humus) and three forest floor habitats (leaf litter, fungal sporocarps, arthropod associates) in the Green Mountains section of Lamington National Park, Queensland, and compared them to 423 specimens collected from the canopy by pyrethrin knockdown (PKD). In total, 165 species (80% new to science) were identified, including 58 from PKD. Few species occurred in more than one habitat, and complementarity averaged 96 ± 1%. About half of the species from PKD were found in canopy habitats, but less than 10% occurred in forest floor habitats. Thus, the canopy fauna is composed primarily of canopy specialists, not of forest floor mites, and habitat specificity is a major component of acarine diversity. An Incidence‐based Coverage estimator (generated by the EstimateS program) proved useful in predicting asymptotes for collector's curves. Conservative extrapolations from this study suggest that more than 2000 species of mites live in subtropical rainforest in the Green Mountains.