Seeps regulate stream nitrate concentration in a forested Appalachian catchment.

摘要: Surface seeps can be defined as locations where upwelling ground water saturates the surface for most of year and excess delivered to stream channel via flowpaths. If a is predominantly fed by seeps, then added these flowpaths may result in reduced interactions with subsurface riparian zone. It generally believed that seep upwells flows along subject diminished denitrification biologic uptake processes. Seep effects on nitrate (NO 3 ) concentration were studied Baldwin Creek (5.35 km 2 ), southwestern Pennsylvania. Nitrate retention within zones was evaluated over 1-yr period (May 2002-2003) using monthly, nested (top bottom seep) sampling approach 15 individual seeps. samples analyzed NO -N, NH dissolved organic carbon, waters streamflow measurements at seven stations. Seeps sinks concentrations decreasing downseep: 31% median annual reduction 73% maximum monthly reduction. During cold wet periods, frequently behaved sources increased or remained constant downseep). temperature discharge related seasonal variability retention. Seasonal variations have been attributed upland soil vegetation processes numerous watersheds. At Creek, processing regulated concentrations. These results suggest provide important quality functions modulate elevated regional N deposition Appalachian catchments.