Aim The drivers of phylogenetic beta diversity include both local processes (e.g. environmental filtering) and regional processes (e.g. dispersal limitation). The role of environmental filtering can be investigated more directly by analysing community-environment associations, but dispersal limitation is one of the most challenging processes to examine. We investigated the role of traits related to dispersal -flight capacity, body size and voltinism -as drivers of phylogenetic distance decay relationships in Neotropical stream insect communities.Location Headwater streams spread over 600 km in south-eastern Brazil.Methods We compiled a data set of aquatic insect communities inhabiting streams across the State of São Paulo (Brazil). Then, we investigated environmental and spatial signals on phylobetadiversity patterns of aquatic insects using Mantel tests, multiple regressions on distance matrices and variation partitioning. We employed null models to investigate whether phylogenetic distance decay differed from pure compositional distance decay. We deconstructed the data set based on dispersal-related traits; we then ran distance decay analyses for these subsets separately.Results Geographical distance, rather than environmental distance, better explained the patterns of phylobetadiversity. We found that the phylogenetic decay relationship differed from the relationship expected for the null models only for univoltine, large-bodied genera with a high-flight capacity.Main conclusions Dispersal limitation, rather than species sorting, was the main driver for phylogenetic beta diversity in the metacommunity that we studied. We suggest that life-history strategies and mainly voltinism drive the distance decay of similarity in the insect communities examined. We additionally discuss the role of dispersal events over time to explain differences in distance decay patterns among tropical and other regions.

The development of biomonitoring programs based on the macroinvertebrate community requires the understanding of species distribution patterns, as well as of the responses of the community to anthropogenic stressors. In this study, 49 metrics were tested as potential means of assessing the condition of 29 first- and second-order streams located in areas of differing types of land use in São Paulo State, Brazil. Of the sampled streams, 15 were in well-preserved regions in the Atlantic Forest, 5 were among sugarcane cultivations, 5 were in areas of pasture, and 4 were among eucalyptus plantations. The metrics were assessed against the following criteria: (1) predictable response to the impact of human activity; (2) highest taxonomic resolution, and (3) operational and theoretical simplicity. We found that 18 metrics were correlated with the environmental and spatial predictors used, and seven of these satisfied the selection criteria and are thus candidates for inclusion in a multimetric system to assess low-order streams in São Paulo State. These metrics are family richness; Ephemeroptera, Plecoptera and Trichoptera (EPT) richness; proportion of Megaloptera and Hirudinea; proportion of EPT; Shannon diversity index for genus; and adapted Biological Monitoring Work Party biotic index.

The idea behind multimetric indices is to integrate information from several metrics to provide a general classification of water bodies without losing the particularities of each individual metric. Historically, multimetric indices use information on richness, taxon sensitivity, and taxonomic diversity. Recently, functional and phylogenetic diversity proved to capture different dimensions of biodiversity. Here we asked if these new metrics provide complementary information to classical metrics and should be included in multimetric indices. We used an index construction protocol based on statistical filters to test candidate metrics for range, sensitivity, and redundancy. We used macroinvertebrate data from streams located in a Savanna region of Brazil, encompassing a gradient of impact, to test our ideas. Of 41 candidate metrics, functional dispersion of functional diversity, mean nearest neighbor distance of phylogenetic diversity, and four classical metrics passed the filter selection composing the final multimetric index. Our results indicated that functional and phylogenetic diversity metrics indeed responded to environmental impact and complemented the information provided by classical metrics. We suggest that future indices should consider including new metrics of functional and phylogenetic diversity to properly monitor multiple dimensions of biodiversity.

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Appropriate sampling effort is crucial for ecologists. Procrustes analysis can be used to tackle this question by quantifying the match between subsamples and the complete dataset. We used stream macroinvertebrates to show how sampling design can be optimized by reducing the number of subsamples and increasing the number of sites.Abstract in Portuguese is available with online material.