Journal article
Hydrologic connectivity increases denitrification in the hyporheic zone and restored floodplains of an agricultural stream
Journal of Geophysical Research: Biogeosciences, Vol.117(G3), p.n/a
09/2012
Handle:
https://hdl.handle.net/2376/105859
Abstract
Stream ecotones, specifically the lateral floodplain and subsurface hyporheic zone, can be important sites for nitrogen (N) removal via denitrification, but their role in streams with constructed floodplains has not been examined. We studied denitrification in the hyporheic zone and floodplains of an agriculturally influenced headwater stream in Indiana, USA, that had floodplains added as part of a “two‐stage ditch” restoration project. To examine the potential for N removal in the hyporheic zone, we seasonally measured denitrification rates and nitrate concentrations by depth into the stream sediments. We found that nitrate concentration and denitrification rates declined with depth into the hyporheic zone, but denitrification was still measureable to a depth of at least 20 cm. We also measured denitrification rates on the restored floodplains over the course of a flood (pre, during, and post‐inundation), and also compared denitrification rates between vegetated and non‐vegetated areas of the floodplain. We found that floodplain denitrification rates increased over the course of a floodplain inundation event, and that the presence of surface water increased denitrification rates when vegetation was present. Stream ecotones in midwestern, agriculturally influenced streams have substantial potential for N removal via denitrification, particularly when they are hydrologically connected with high‐nitrate surface water.
Key Points
The hyporheic zone has high denitrification rates when connected to surfacewater
Denitrification rates increase during floodplain inundation
Ecotones have substantial N‐removal potential in agricultural streams
Metrics
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Details
- Title
- Hydrologic connectivity increases denitrification in the hyporheic zone and restored floodplains of an agricultural stream
- Creators
- Sarah S RoleyJennifer L TankMaureen A Williams
- Publication Details
- Journal of Geophysical Research: Biogeosciences, Vol.117(G3), p.n/a
- Academic Unit
- Environment, School of the (CAS)
- Number of pages
- 16
- Grant note
- National Science Foundation (0504495)
- Identifiers
- 99900547087301842
- Language
- English
- Resource Type
- Journal article