Environmental predictors affect α- and β-diversity of tropical bromeliad macroinvertebrates

We tested the hypothesis that abiotic predictors, both influence α and β-diversity of macroinvertebrate communities in the phytotelmata of the terrestrial bromeliad, Vriesea philippocoburgii. Macroinvertebrates were sampled in 58 bromeliads in a restinga in Brazil and estimated both the α and β-diversity in each bromeliad, and then partitioning them into nestedness and turnover. We then used Generalized Linear Models and partial Mantel tests to identify which environmental factors predict these diversity components for the macroinvertebrate communities. The size of the plant positively influenced α-diversity, whereas light intensity strongly influenced β-diversity. Both components were influenced by organic matter. Plants exhibiting large differences in values of organic matter and light intensity had different macroinvertebrate communities. Furthermore, bromeliad systems exhibit high β-diversity values governed by turnover. Our findings demonstrate the importance of considering α and β-diversities in studies that assess the diversity patterns of aquatic macroinvertebrates and suggest that environmental changes that modify the structure of aquatic macroinvertebrate communities could have impacts on ecosystem processes.