, Volume 111, Issue 1–3, pp 647–660 | Cite as

Nitrate removal in two relict oxbow urban wetlands: a 15N mass-balance approach

  • Melanie D. Harrison
  • Peter M. Groffman
  • Paul M. Mayer
  • Sujay S. Kaushal


A 15N-tracer method was used to quantify nitrogen (N) removal processes in two relict oxbow wetlands located adjacent to the Minebank Run restored stream reach in Baltimore County (Maryland, USA) during summer 2009 and early spring 2010. A mass-balance approach was used to directly determine the flow of 15NO3 to plants, algae, and sediments, with unaccounted for 15N assumed to be denitrified. During the summer, plant and algal uptake accounted for 42%, of the added 15NO3 in oxbow 1, less than 1% remained in the water column and 57% was unaccounted for. In oxbow 2 during the summer, plant and algal uptake accounted for 63% of the added 15NO3 , with <1% remaining in the water column and 38% unaccounted for. During the early spring, plant and algal uptake were much lower in both oxbows, ranging from 0.05 to 13.3% of the 15N added, with 97 and 87% was unaccounted for in oxbow 1 and 2, respectively. The amount of unaccounted for 15N was equivalent to estimated areal denitrification rates of 12 and 6 mg N m−2 d−1 in the summer and 78 and 15 mg N m−2 d−1 in the spring, in oxbow 1 and oxbow 2, respectively. However, the uncertainty of these estimates is high as it was difficult to detect accumulation of 15N in the sediments which could have accounted for a very large percentage of the added 15N. Our results suggest that the two relict oxbow wetlands are sinks for NO3 during both summer and spring but that the pathways of removal vary with plants and algae playing a major role in summer but not in spring.


Algae Denitrification Macrophytes Nitrogen Sediment 



This research was supported by grants from the U.S. Environmental Protection Agency (CR829676), the U.S. National Science Foundation (NSF) Long-Term Ecological Research program (DEB-0423476), the NSF Integrative Graduate Education and Research Traineeship Program (0549469), the NSF Division of Biological Infrastructure (DBI 06-40300), Maryland Sea Grant award (SA7528085-U), and the NOAA Educational Partnership Graduate Science Program (GSP). We thank Dan Dillon, Dave Lewis, Lisa Martel, Robin Schmidt, Daniel Jones, and Emma Noonan for assistance with field and laboratory work, and Andrew Miller and Christopher Swan for thoughtful comments and review of the manuscript. The research has not been subjected to EPA review and therefore does not necessarily reflect the views of any of the funding agencies, and no official endorsement should be inferred.


  1. Aulakh MS, Doran JW, Mosier AR (1992) Soil denitrification: significance, measurement and effects of management. Adv Soil Sci 18:1–57CrossRefGoogle Scholar
  2. Bachand PAM, Horne AJ (2000) Denitrification in constructed free-water surface wetlands: II. Effects of vegetation and temperature. Ecol Eng 14(1–2):17–32Google Scholar
  3. Beaulieu JJ, Tank JL, Hamilton SK, Wollheim WM, Hall RO, Mulholland PJ, Peterson BJ, Ashkenas LR, Cooper LW, Dahm CN (2011) Nitrous oxide emission from denitrification in stream and river networks. Proc Natl Acad Sci 108:214–219CrossRefGoogle Scholar
  4. Boesch DF, Brinsfield RB, Magnien RE (2001) Chesapeake Bay eutrophication: Scientific understanding, ecosystem restoration, and challenges for agriculture. J Environ Qual 30(2):303–320CrossRefGoogle Scholar
  5. Borin M, Tocchetto D (2007) Five year water and nitrogen balance for a constructed surface flow wetland treating agricultural drainage waters. Sci Total Environ 380(1–3):38–47CrossRefGoogle Scholar
  6. Bouchard V, Frey SD, Gilbert JM, Reed SE (2007) Effects of macrophyte functional group richness on emergent freshwater wetland functions. Ecology 88(11):2903–2914CrossRefGoogle Scholar
  7. Burgin AJ, Hamilton SK (2007) Have we overemphasized the role of denitrification in aquatic ecosystems? A review of nitrate removal pathways. Front Ecol Environ 5:89–96CrossRefGoogle Scholar
  8. Chang C, Janzen HH, Cho CM, Nakonechny EM (1998) Nitrous oxide emission through plants. Soil Sci Soc Am J 62(1):35–38CrossRefGoogle Scholar
  9. Clough TJ, Jarvis SC, Dixon ER, Stevens RJ, Laughlin RJ, Hatch DJ (1999) Carbon induced subsoil denitrification of N-15-labelled nitrate in 1 m deep soil columns. Soil Biol Biochem 31(1):31–41CrossRefGoogle Scholar
  10. Clough TJ, Sherlock RR, Cameron KC, Stevens RJ, Laughlin RJ, Muller C (2001) Resolution of the N-15 balance enigma? Aust J Soil Res 39(6):1419–1431CrossRefGoogle Scholar
  11. Curtis CJ, Evans CD, Goodale CL, Heaton THE (2011) What have stable isotope studies revealed about the nature and mechanisms of N saturation and nitrate leaching from semi-natural catchments? Ecosystems 14(6):1021–1037CrossRefGoogle Scholar
  12. Doheny EJ, Starsoneck RJ, Striz EA, Mayer PM (2006) Watershed characteristics and pre-restoration surface-water hydrology of Minebank Run, Baltimore County, Maryland, water years 2002–2004. In: USGS scientific investigations report. vol 2006–5179. USGS, RestonGoogle Scholar
  13. Doheny EJ, Starsoneck RJ, Mayer PM, Striz EA (2007) Pre-restoration geomorphic characteristics of Minebank Run, Baltimore County, Maryland, 2002-04. In: USGS scientific investigations report. vol 2007–5127. USGS, RestonGoogle Scholar
  14. Erler DV, Eyer BD (2010) Quantifying nitrogen process rates in a constructed wetland using natural abundance stable isotope signatures and stable isotope amendment experiments. J Environ Qual 39:2191–2199CrossRefGoogle Scholar
  15. Gale PM, Devai I, Reddy KR, Graetz DA (1993) Denitrification potential of soils from constructed and natural wetlands. Ecol Eng 2(2):119–130CrossRefGoogle Scholar
  16. Gallegos CL, Jordan TE, Correll DL (1992) Event-scale response of phytoplankton to watershed inputs in a subestuary: timing, magnitude, and location of blooms. Limnol Oceanogr 37(4):813–828CrossRefGoogle Scholar
  17. Gift DM, Groffman PM, Kaushal SS, Mayer PM (2010) Denitrification potential, root biomass, and organic matter in degraded and restored urban riparian zones. Restor Ecol 18:113–120CrossRefGoogle Scholar
  18. Groffman PM, Dorsey AM, Mayer PM (2005) N processing within geomorphic structures in urban streams. J N Am Benthol Soc 24:613–625Google Scholar
  19. Hall RO, Baker MA, Arp CD, Koch BJ (2009) Hydrologic control of nitrogen removal, storage, and export in a mountain stream. Limnol Oceanogr 54(6):2128–2142CrossRefGoogle Scholar
  20. Harrison MD, Groffman PM, Mayer PM, Kaushal SS, Newcomer TA (2011) Denitrification in alluvial wetlands in an urban landscape. J Environ Qual 40(2):634–646CrossRefGoogle Scholar
  21. Hernandez ME, Mitsch WJ (2007) Denitrification in created riverine wetlands: influence of hydrology and season. Ecol Eng 30(1):78–88CrossRefGoogle Scholar
  22. Huang J, Mitsch WJ, Johnshon DL (2011) Estimating biogeochemical and biotic interactions between a stream channel and a created riparian wetland: a medium-scale physical model. Ecol Eng 37:1035–1049CrossRefGoogle Scholar
  23. Jordan TE, Correll DL, Miklas J, Weller DE (1991a) Long-term trends in estuarine nutrients and chlorophyll, and short-term effects of variation in watershed discharge. Marine Ecol-Progress Series 75(2–3):121–132CrossRefGoogle Scholar
  24. Jordan TE, Correll DL, Miklas J, Weller DE (1991b) Nutrients and chlorophyll at the interface of a watershed and an estuary. Limnol Oceanogr 36(2):251–267CrossRefGoogle Scholar
  25. Jordan TE, Whigham DF, Hofmockel KH, Pittek MA (2003) Nutrient and sediment removal by a restored wetland receiving agricultural runoff. J Environ Qual 32(4):1534–1547CrossRefGoogle Scholar
  26. Jordan S, Stoffer J, Nestlerode J (2011) Wetlands as sinks for reactive nitrogen at continental and global scales: a meta-analysis. Ecosystems 14(1):144–155CrossRefGoogle Scholar
  27. Kadlec RH (1994) Wetlands for water polishing: free water surface wetlands. In: Mitsch WJ (ed) Global wetlands: old world and new. Elsevier, New York, p 335–349Google Scholar
  28. Kadlec RH, Knight RL (1996) Treatment wetlands. Lewis Publishing, New YorkGoogle Scholar
  29. Kaushal SS, Groffman PM, Mayer PM, Striz E, Gold AJ (2008) Effects of stream restoration on denitrification in an urbanizing watershed. Ecol Appl 18(3):789–804CrossRefGoogle Scholar
  30. Kemp WM, Twilley RR, Stevenson JC, Boynton WR, Means JC (1983) The decline of submerged vascular plants in upper Chesapeake Bay: Summary of results concerning possible causes. Marine Technol Soc J 17(2):78–89Google Scholar
  31. Kleeberg A, Heidenreich M (2004) Release of nitrogen and phosphorus from macrophyte stands of summer dried out sediments of a eutrophic reservoir. Arch Hydrobiol 159:115–136CrossRefGoogle Scholar
  32. Klocker C, Kaushal S, Groffman P, Mayer P, Morgan R (2009) Nitrogen uptake and denitrification in restored and unrestored streams in urban Maryland, USA. Aqua Sci 71(4):411–424CrossRefGoogle Scholar
  33. Kreiling RM, Richardson WB, Cavanaugh JC, Barsch LA (2011) Summer nitrate uptake and denitrification in an upper Mississippi River backwater lake: the role of rooted aquatic vegetation. Biogeochemistry 104:309–324CrossRefGoogle Scholar
  34. Lin YF, Jing SR, Wang TW, Lee DY (2002) Effects of macrophytes and external carbon sources on nitrate removal from groundwater in constructed wetlands. Environ Pollut 119(3):413–420CrossRefGoogle Scholar
  35. Matheson FE, Sukias JP (2010) Nitrate removal processes in a constructed wetland treating drainage from dairy pasture. Ecol Eng 36(10):1260–1265CrossRefGoogle Scholar
  36. Matheson FE, Nguyen ML, Cooper AB, Burt TP, Bull DC (2002) Fate of N-15-nitrate in unplanted, planted and harvested riparian wetland soil microcosms. Ecol Eng 19(4):249–264CrossRefGoogle Scholar
  37. Mayer PM, Groffman PM, Striz EA, Kaushal SS (2010) Nitrogen dynamics at the groundwater-surface water interface of a degraded urban stream. J Environ Qual 39(3):810–823CrossRefGoogle Scholar
  38. McGill BM, Sutton-Grier AE, Wright JP (2010) Plant trait diversity buffers variability in denitrification potential over changes in season and soil conditions. Plos One 5(7):e11618Google Scholar
  39. McKellar HN Jr, Tufford DL, Alford MC, Saroprayogi P, Kelley BJ, Morris JT (2007) Tidal nitrogen exchanges across a freshwater wetland succession gradient in the upper Cooper River, South Carolina. Estuaries Coast 30:989–1006Google Scholar
  40. McMillan SK, Piehler MF, Thompson SP, Paerl HW (2010) Denitrification of nitrogen release from senescing algal biomass in coastal agricultural headwater streams. J Environ Qual 39:274–281Google Scholar
  41. Mitsch WJ (1994) The nonpoint source pollution control function of natural and constructed riparian wetlands. In: Mitsch WJ (ed) Global wetlands: old world and new. Elsevier, New York, pp 351–361Google Scholar
  42. Moraghan JT (1993) Loss and assimilation of N-15-nitrate added to a North-Dakota cattail marsh. Aquat Bot 46(3–4):225–234CrossRefGoogle Scholar
  43. Morgan JA, Martin JF, Bouchard V (2008) Identifying plant species with root associated bacteria that promote nitrification and denitrification in ecological treatment systems. Wetlands 28(1):220–231CrossRefGoogle Scholar
  44. Mosier AR, Mohanty SK, Bhadrachalam A, Chakravorti SP (1990) Evolution of dinitrogen and nitrous-oxide from the soil to the atmosphere through rice plants. Biol Fertil Soils 9(1):61–67CrossRefGoogle Scholar
  45. Mulholland PJ, Hall RO, Sobota DJ, Dodds WK, Findlay SE, Grimm NG, Hamilton SK, McDowell WH, O’Brien JM, Tank JL, Ashkenas LR, Cooper LW, Dahm CN, Gregory SV, Johnson SL, Meyer JL, Peterson BJ, Poole GC, Valett MH, Webster JR, Arango CP, Beaulieu JJ, Bernot MJ, Burgin AJ, Crenshaw CL, Helton AM, Johnson MJ, Niederlehner BR, Potter JD, Shiebley RW, Thomas SM (2009) Nitrate removal in stream ecosystem measured by 15 N addition experiments: denitrification. Limnol Oceanogr 54(3):666–680CrossRefGoogle Scholar
  46. Nijburg JW, Laanbroek HJ (1997) The fate of N-15-nitrate in healthy and declining Phragmites australis stands. Microb Ecol 34(3):254–262CrossRefGoogle Scholar
  47. Officer CB, Biggs RB, Taft JL, Cronin LE, Tyler MA, Boynton WR (1984) Chesapeake Bay anoxia: origin, development, and significance. Science 223(4631):22–27CrossRefGoogle Scholar
  48. Parkin TB (1987) Soil microsites as a source of denitrification variability. Soil Sci Soc Am J 51(5):1194–1199CrossRefGoogle Scholar
  49. Paul MJ, Meyer JL (2001) Streams in the urban landscape. Ann Rev Ecol Syst 32:333–365CrossRefGoogle Scholar
  50. Pellerin BA, Kaushal SS, McDowell WH (2006) Does anthropogenic nitrogen enrichment increase organic nitrogen concentrations in runoff from forested and human-dominated watersheds? Ecosystems 9(5):852–864CrossRefGoogle Scholar
  51. Prather M, Derwent R, Ehhalt D, Fraser PJ, Sanhueza E, Zhou X (1995) Other trace gases and atmospheric chemistry. In: Houghton JT, Meiro Filho LG, Callander BA, Harris N, Kattenburg A, Maskell K (eds) Climate change 1994: radiative forcing of climate change and an evaluation of the IPCC IS92 emission scenarios, Cambridge University Press, New York, pp 73–126Google Scholar
  52. Reddy KR, DeLaune RD (2008) Biogeochemistry of wetlands: science and applications. CRC Press, Boca RatonCrossRefGoogle Scholar
  53. Reddy KR, Patrick WH (1984) Nitrogen transformations and loss in flooded soils and sediments. CRC Crit Rev Environ Control 13(4):273–309CrossRefGoogle Scholar
  54. Reddy GB, Patrick WH (1999) Biogeochemistry of wetlands. CRC/Lewis Publishers, Boca RatonGoogle Scholar
  55. Reddy KR, Patrick WH, Lindau CW (1989) Nitrification-denitrification at the plant root-sediment interface in wetlands. Limnol Oceanogr 34(6):1004–1013CrossRefGoogle Scholar
  56. Rolston DE, Broadbent FE, Goldhamer DA (1979) Field measurement of denitrification: II. Mass balance and sampling uncertainty. Soil Sci Soc Am J 43(4):703–708CrossRefGoogle Scholar
  57. Rotkin-Ellman M, Addy K, Gold AJ, Groffman PM (2004) Tree species, root decomposition and subsurface denitrification potential in riparian wetlands. Plant Soil 263(1–2):335–344CrossRefGoogle Scholar
  58. Ruckauf U, Augustin J, Russow R, Merbach W (2004) Nitrate removal from drained and reflooded fen soils affected by soil N transformation processes and plant uptake. Soil Biol Biochem 36(1):77–90CrossRefGoogle Scholar
  59. Schimel DS, Paul EA, Melillo J (1993) Theory and application of tracers (isotopic techniques in plant, soil, and aquatic biology). Academic Press, New YorkGoogle Scholar
  60. Schlesinger WH (2009) On the fate of anthropogenic nitrogen. Proc Natl Acad Sci 106(1):203–208CrossRefGoogle Scholar
  61. Seitzinger S, Harrison JA, Bohlke JK, Bouwman AF, Lowrance R, Peterson B, Tobias C, Van Drecht G (2006) Denitrification across landscapes and waterscapes: a synthesis. Ecol Appl 16(6):2064–2090CrossRefGoogle Scholar
  62. Sivirichi GM, Kaushal SS, Mayer PM, Welty C, Belt KT, Newcomer TA, Newcomb KD, Grese MM (2011) Longitudinal variability in streamwater chemistry and carbon and nitrogen fluxes in restored and degraded urban stream networks. J Environ Monitor 13(2):288–303CrossRefGoogle Scholar
  63. Spieles DJ, Mitsch WJ (2000) The effects of season and hydrologic and chemical loading on nitrate retention in constructed wetlands: a comparison of low- and high-nutrient riverine systems. Ecol Eng 14(1–2):77–91Google Scholar
  64. Stark JM, Hart SC (1996) Diffusion technique for preparing salt solutions, Kjeldahl digests, and persulfate digests for nitrogen-15 analysis. Soil Sci Soc Am J 60(6):1846–1855CrossRefGoogle Scholar
  65. Strauss EA, Richardson WB, Cavanaugh JC, Bartsch LA, Kreiling RM, Standorf AJ (2006) Variability and regulation of denitrification in an Upper Mississippi River backwater. J N Am Benthol Soc 25(3):596–606CrossRefGoogle Scholar
  66. Striz EA, Mayer PM (2008) Assessment of near-stream ground water-surface water interaction (GSI) of a degraded stream before restoration. In. vol EPA/600/R-07/058. Environmental Protection Agency, Washington, DCGoogle Scholar
  67. Sutton-Grier AE, Wright JP, McGill BM, Richardson C (2011) Environmental conditions influence the plant functional diversity effect on potential denitrification. PLoS ONE 6(2):e16584CrossRefGoogle Scholar
  68. Tabatabai MA, Dick WA (1983) Simultaneous determination of nitrate, chloride, sulfate, and phosphate in natural waters by ion chromatography. J Environ Qual 12(2):209–213CrossRefGoogle Scholar
  69. Tanner CC (2001) Plants as ecosystem engineers in subsurface-flow treatment wetlands. Water Sci Technol 44(11/12):9–17Google Scholar
  70. Tanner CC, Nguyen ML, Sukias JPS (2005) Nutrient removal by a constructed wetland treating subsurface drainage from grazed dairy pasture. Agric Ecosyst Environ 105(1–2):145–162CrossRefGoogle Scholar
  71. Vymazal J (2007) Removal of nutrients in various types of constructed wetlands. Sci Total Environ 380:48–65CrossRefGoogle Scholar
  72. Walsh CJ, Roy AH, Feminella JW, Cottingham PD, Groffman PM, Morgan RP (2005) The urban stream syndrome: current knowledge and the search for a cure. J N Am Benthol Soc 24:706–723Google Scholar
  73. Xue Y, Kovacic DA, David MB, Gentry LE, Mulvaney RL, Lindau CW (1999) In situ measurements of denitrification in constructed wetlands. J Environ Qual 28(1):263–269CrossRefGoogle Scholar
  74. Zhang L, Mitsch WJ (2005) Modelling hydrological processes in created freshwater wetlands: an integrated system approach. Environ Model Software 20(7):935–946CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  • Melanie D. Harrison
    • 1
    • 5
  • Peter M. Groffman
    • 2
  • Paul M. Mayer
    • 3
  • Sujay S. Kaushal
    • 4
  1. 1.Marine Estuarine and Environmental Science ProgramUniversity of Maryland Baltimore CountyBaltimoreUSA
  2. 2.Cary Institute of Ecosystem StudiesNew YorkUSA
  3. 3.National Risk Management Research Lab, Ground Water and Ecosystems Restoration DivisionUS Environmental Protection AgencyOklahomaUSA
  4. 4.Department of Geology and Earth Systems Science Interdisciplinary CenterUniversity of MarylandCollege ParkUSA
  5. 5.Southwest Region, Protected Resources DivisionNational Oceanic and Atmospheric AdministrationSanta RosaUSA

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