How does water current velocity affect invertebrate community and leaf‐litter breakdown in a physicochemically stable freshwater ecosystem? An experimental study in two nearby reaches (erosional vs. depositional) of the Vera Spring (Central Italy)

The decomposition of allochthonous dead organic matter is a key process for the metabolism and functioning stream spring ecosystems. litter breakdown influenced by several abiotic biotic factors. Among parameters, role current velocity physical abrasion was poorly investigated. Field studies gave contrasting results, mainly because covariation interaction with other biotic/abiotic variables. For these reasons, we assessed leaf-litter structure crenic assemblages in two nearby reaches (erosional vs. depositional) physicochemically stable rheocrene spring. zones investigated were characterized similar environmental conditions, but water about four times greater erosional reach. We found substantial differences functional organization assemblages. Overall taxa richness density higher depositional reach, while diversity abundance Ephemeroptera, Plecoptera Trichoptera taller zone. Shredders more abundant zone, scrapers represented slow sector also demonstrated that flow may promote faster leaf detritus reach through indirect effects: shredder detritivores. Our results indicate have affecting both assemblage composition ecosystem processes.