Beta diversity of aquatic insects (Ephemeroptera, Plecoptera and Trichoptera) across stream microhabitats

Diversidade beta de insetos aquáticos (Ephemeroptera, Plecoptera e Trichoptera) em microhabitats de riachos

Abstract:

Aim  We evaluated how the combination of environmental characteristics affects the beta diversity of the EPT (Ephemeroptera, Plecoptera and Trichoptera) community across stream microhabitats.

Methods  The samples were collected in 12 streams around the Itaipu Reservoir (Paraná, Brazil). We sampled four types of substrates in triplicate with the aid of a Surber sampler. The samples were classified into CSD (sand and clay) and STO (gravel, pebbles, and boulders). The composite substrate of leaf packs (leaves and twigs) was divided into RLP (rapid leaf packs) and BLP (backwater leaf packs).

Results  We recorded a significant change in EPT composition among the microhabitats evaluated and different genera associated with each substrate category. However, beta diversity did not significantly differ among microhabitats. Thus, we found the highest beta diversity value in the CSD (sand and clay) category and the greatest contribution of the turnover component.

Conclusions  The partitioning of beta diversity into its components helped understand ecological patterns at local scales, highlighting the importance of microhabitat diversity in stream systems for maintaining the structure and composition of aquatic fauna.

Keywords:
small scales; turnover; nestedness; aquatic insects; streams