In–stream nitrogen processing in urban degraded and restored streams in Baltimore, MD Carolyn A. Klocker (UMCES) Sujay Kaushal (UMCES), Peter Groffman (IES), and Paul Mayer (EPA) BES Annual Meeting 10/19/06

Nitrogen retention and removal in streams Nitrogen being retained and removed in both small headwater streams (Peterson et al 2001) and larger rivers ≥ 5 th order (Seitzinger et al 2002) Nitrogen being retained and removed in both small headwater streams (Peterson et al 2001) and larger rivers ≥ 5 th order (Seitzinger et al 2002) Nitrogen retention or removal Nitrogen retention or removal = Inputs - Outputs Includes biotic uptake, retention in sediments and denitrification Includes biotic uptake, retention in sediments and denitrification

Sediment inputs Nutrient inputs Bank Incision Removal of riparian zone Stream Degradation Increased Nitrogen Concentrations Lateral movement of stream channel

Stream Restoration Bank re-shaping Cross Vane Re-vegetation Rip Rap Channel manipulation Substrate manipulation Erosion control

Objective To determine the nitrogen retention ability of 4 urban streams, 2 restored and 2 degraded, using the metrics of nutrient spiraling theory. To determine the nitrogen retention ability of 4 urban streams, 2 restored and 2 degraded, using the metrics of nutrient spiraling theory. uptake length, uptake rate, and uptake velocity uptake length, uptake rate, and uptake velocity To compare these values to known literature values recently reported To compare these values to known literature values recently reported

Nutrient spiraling theory NO 3

Retention Parameters Uptake length Uptake length S w = Q C S w = Q C U w U w Uptake rate Uptake rate U = v f C U = v f C Uptake velocity Uptake velocity v f = Q v f = Q S w w S w w Q = discharge C = concentration of nutrient w = stream width (Stream Solute Workshop 1990)

Nutrient additions Goals Goals To add a solution increasing the nutrient in question (NO 3 -) and a conservative tracer (Br-) To add a solution increasing the nutrient in question (NO 3 -) and a conservative tracer (Br-) Allow the concentrations to reach plateau Allow the concentrations to reach plateau Uptake length = the inverse slope of the regression of the ln (corrected concentration) of NO 3 - verses distance downstream Uptake length = the inverse slope of the regression of the ln (corrected concentration) of NO 3 - verses distance downstream

Minebank Run Minebank Run 2 nd order stream 2 nd order stream Upstream reach restored Upstream reach restored in 1998 and 1999 in 1998 and 1999 Goal of the restoration was to improve the geomorphic stability of the stream bed and reduce incision Goal of the restoration was to improve the geomorphic stability of the stream bed and reduce incision Restoration Sites

Spring Branch Spring Branch 1 st order stream 1 st order stream Loch Raven Watershed Loch Raven Watershed Drains directly into the Loch Drains directly into the Loch Raven Reservoir Raven Reservoir Restoration Restoration Goal of the restoration was to manage the flow of the stream to control for erosion and floods Goal of the restoration was to manage the flow of the stream to control for erosion and floods

Glyndon Glyndon 1 st order stream 1 st order stream BES LTER stream BES LTER stream Gwynn Falls Watershed Gwynn Falls Watershed Visible channel incision Visible channel incision Little riparian buffer Little riparian buffer Analytical problems Analytical problems Interference with Bromide Interference with Bromide Degraded Sites

DR 5 DR 5 Headwater tributary of Headwater tributary of the larger 3 rd order the larger 3 rd order Dead Run Dead Run Gwynn Falls Watershed Gwynn Falls Watershed Little riparian buffer Little riparian buffer Visible channel incision Visible channel incision

Methods NO 3 - and Br- added for approximately 8-10 hrs at 45 mL/min NO 3 - and Br- added for approximately 8-10 hrs at 45 mL/min 5 sampling locations 5 sampling locations Collected approx. every 30 minutes Collected approx. every 30 minutes Samples were filtered, frozen and analyzed using a dx 500 Ion Chromatograph Samples were filtered, frozen and analyzed using a dx 500 Ion Chromatograph I A B C D E

NO 3 - QSwSw Uvfvf SiteType (mg/L) (L/s)(m)(μg N m -2 s -1 )(mm/s) GLYNDegraded DR5Degraded X MNBKRestored X SPBRRestored X Results

NO 3 -Q SwSw Uvfvf SiteType(mg/L)(L/s) (m) (μg N m -2 s -1 )(mm/s) GLYNDegraded DR5Degraded X MNBKRestored X SPBRRestored X Results

NO 3 -QSwSw Uvfvf SiteType(μg/L)(L/s)(m)(μg N m -2 s -1 )(mm/s) SPBRRestored x DR5Degraded x MNBKRestored x GLYNDegraded AFRUnaltered SYCUnaltered RRDEarthen IBWEarthen GDREarthen PRDConcrete HLCConcrete DMB-DAgriculture DMB-PAgriculture Erpe-DAgriculture Erpe-PAgriculture (Grimm 2005, Gucker and Pusch 2006) 800 to 16400

Implications and Future Directions As restoration projects age the may be able to retain nitrogen more efficiently Need to look at more than just the state of the stream Watershed characteristics DOC Periphyton densities and chlorophyll a Geomorphic structures

Data to be analyzed Isotope additions Isotope additions Maintain ambient nutrient concentrations Maintain ambient nutrient concentrations In situ denitrification rates In situ denitrification rates 2 completed at Minebank Run in August completed at Minebank Run in August 2006 Denitrification Enzyme Assays (DEA) Denitrification Enzyme Assays (DEA) Conducted at all 4 sites in late June to early July of 2006 Conducted at all 4 sites in late June to early July of 2006

Acknowledgements Sujay Kaushal, Paul Mayer, and Peter Groffman Sujay Kaushal, Paul Mayer, and Peter Groffman Pete Bogush and Tammy Newcomer Pete Bogush and Tammy Newcomer Dan Dillon, Ho-Jin Kim Dan Dillon, Ho-Jin Kim Paul Lilly and Melanie Paul Lilly and Melanie Harrison Harrison Katie Kline and Katie Kline and Keith Eshleman EPA and AL EPA and AL

Restored Urban Stream: Developed Stage Increased organic matter Healthy riparian zones Decreased Nitrogen Concentrations ????