Factors explaining the diversity of invertebrates inhabiting woods in the Paraná River wetlands

Abstract

Wetlands provide ecosystem services linked to the roles that macroinvertebrates play. These habitats have been highly deteriorated in the last decades. Predicting species assemblages and their response to a changing landscape requires a better understanding of the factors that drive variation in species abundance and distribution in natural conditions. Besides, woody debris support a diverse biota and have been promoted for river rehabilitation, restoration, and management. To assess whether invertebrates colonized the surface of submerged woods, 28 woody debris were collected in wetlands along the Paraná River floodplain. Taxonomic richness, diversity and evenness, and functional diversity of assemblages were explored. To quantify the relative role of environmental (i.e. limnological and wood parameters), spatial, and dispersal traits factors in explaining the composition and diversity of communities, redundancy, and variation partitioning analyses were run. All the substrates were colonized and macroinvertebrates were abundant and diverse. Functional alpha and beta redundancy were low due to a high turnover of species performing different functions, and a low dominance of species. The analysed factors explained around 50% of the variability in the biotic patterns analysed. In the Paraná River, woody debris is probed to be substrates useful for restoring diversity and functions and thus can support important ecosystem services wetlands provide. All the factors analysed partially supported the diversity, composition, and functions, but dispersal, spatial and limnological factors were the most important and strategies should consider them prior to wood characteristics.