Tracing the pathways from urbanization to ecosystem functioning in streams

We quantified water quality, macroinvertebrate community composition, trophic structure derived from stable isotopes, and leaf litter decomposition rates to assess how abiotic, biotic and functional attributes respond to increasing urban pressure.

Urbanization directly reduced water quality and indirectly altered macroinvertebrate assemblages and trophic complexity. Despite declining macroinvertebrate diversity and reduced macrofaunal contributions to decomposition at high IC, overall decomposition rates increased along the urban gradient. This unexpected pattern suggests compensatory processes, potentially involving microbial pathways, and points to a shift in the dominant mechanisms sustaining decomposition.