Groundwater‐stream connections shape the spatial pattern and rates of aquatic metabolism

A longstanding challenge in stream ecology is to understand how landscape configuration organizes spatial patterns of ecosystem function via lateral groundwater connections. We combined laboratory bioassays and field additions a metabolic tracer (resazurin) test groundwater-stream confluences, or “discrete riparian inflow points” (DRIPs), regulate heterotrophic microbial activity along boreal stream. hypothesized that DRIPs shape rates aquatic by supplying labile dissolved organic matter (DOM) streams. Laboratory showed the potential influence on varied spatially temporally, was related their DOM content composition. At reach scale, DRIP-stream confluences elevated heterogeneity whole-reach activity, especially during periods high land–water hydrological connectivity. Collectively, our results show arrangement connections streams with implications for watershed biogeochemical cycles.