Partitioning Macroinvertebrate Diversity Across Different Spatial Scales in Southern Brazil Coastal Wetlands

The main goals of this study were: (1) test how beta diversity of aquatic macroinvertebrates varies among samples from different spatial scales in permanent and intermittent wetlands; and (2) test how beta diversity of aquatic macroinvertebrates varies among different wetland habitat types. Four collections were carried out over 1 year in 16 freshwater coastal wetlands in southern Brazil. The habitat types identified were: 1) hydrophytes, represented by submersed and floating plants; 2) reed-like emergent plants; and 3) leafy emergent plants. Additive partitioning of diversity was used to decompose the total variation in macroinvertebrate composition (regional diversity) into alpha (fine spatial scale) and beta components (intermediate and broad spatial scales). A total of 51,290 macroinvertebrates distributed among 63 families were collected. Additive partitioning of diversity showed similar patterns for both permanent and intermittent wetlands. In general, alpha diversity component was much lower than beta components. The beta diversity was greater among wetlands than among distinct habitats within wetlands. We found a strong evidence of scale dependence on diversity partitioning of macroinvertebrate communities, with beta diversity at broad spatial scale making a large contribution to total diversity in coastal wetlands of southern Brazil.