Functional responses of benthic macroinvertebrate communities to rural-urban land-use gradients in Neotropical lowland streams

In the province of Entre Ríos (Argentina), streams are increasingly affected by land-use change, including livestock production, urban expansion, and wastewater discharge, which generate multiple stressors such as pollution, sedimentation, hydromorphological alteration, and habitat degradation. This study assessed benthic macroinvertebrate communities in eight streams exposed to contrasting land uses in a Neotropical lowland region of Entre Ríos. Between 2013 and 2019, streams were sampled using a standardized multi-habitat protocol. Community structure, functional feeding groups (FFGs), and ecosystem attributes were analyzed using univariate and multivariate approaches. A total of 64 taxa were recorded, with lower richness in urban streams. Shredders were absent from urban streams and scarce overall. Urban streams also exhibited reduced abundance, functional diversity, and ecosystem attributes. These results indicate that urbanization negatively affects both community structure and ecosystem functioning. Integrating taxonomic and functional approaches can improve ecological assessments and support conservation and management of freshwater ecosystems under anthropogenic pressure.