Taxonomic and functional responses of stream macroinvertebrates across different land use types

Urbanization and agricultural expansion are major drivers of freshwater biodiversity change, yet their effects on functional diversity remain unclear. We investigated the taxonomic and functional diversity of benthic macroinvertebrates across 121 forest, agricultural, and urban stream sites in South Korea. Macroinvertebrates were classified into 28 categories based on nine functional traits. Taxonomic richness was highest in forest streams and lowest in urban streams. Functional richness declined in disturbed streams, while functional divergence increased in urban and agricultural sites, indicating trait specialization under stress. Species such as Asellus sp. and Limnodrilus gotoi dominated in urban and agricultural sites, reflecting tolerance to pollution and sedimentation. In contrast, forest streams supported sensitive taxa with diverse life strategies. Our findings reveal how trait-based approaches complement taxonomic assessments by capturing adaptive responses to land-use changes, emphasizing the importance of incorporating functional diversity into freshwater biodiversity monitoring and conservation strategies.