Environmental gradients and anthropogenic landscape modification determine composition of functional traits of periphyton community in Brazilian Cerrado streams

The environment-species relationships can be mediated by functional traits. In this study we investigated how the functional traits of periphytic community respond to environmental variation in streams along a gradient of anthropically modified landscapes in the Brazilian Cerrado. We expect the association of traits with flow gradients, turbidity, productivity, and nutrients directly impacted by changes in land cover around streams. We use the RLQ analysis to test this hypothesis. The first RLQ axis revealed a gradient associated with variation in the local physical and chemical characteristics, nutrients and productivity of the streams, while the second axis was associated with a gradient of impact on land use and nutrients related to the trophic state. The main traits associated with the first axis of RLQ (physical and chemical, and productivity gradient) were life form, substrate adherence, and active mobility, while size, life form, and substrate adhesion were associated with the second axis of RLQ (land use, primary productivity, and orthophosphate gradient). Our results highlight the importance of the trait-environment approach to predict community composition. Furthermore, they suggest that functional traits can be used to predict the responses of periphytic communities to environmental changes at local and landscape scales.