, Volume 85, Issue 3, pp 333–346 | Cite as

Temperature controls a latitudinal gradient in the proportion of watershed nitrogen exported to coastal ecosystems

  • Sylvia C. Schaefer
  • Merryl AlberEmail author
Original Paper


Increased export of biologically available nitrogen (N) to the coastal zone is strongly linked to eutrophication, which is a major problem in coastal marine ecosystems (NRC (2000) Clean Coastal Waters: Understanding and Reducing the Effects of Nutrient Pollution. National Academy Press, Washington, DC; Bricker et al. (1999) National Estuarine Eutrophication Assessment. Effects of nutrient enrichment in the nation’s estuaries. NOAA-NOS Special Projects Office, Silver Spring, MD). However, not all of the nitrogen input to a watershed is exported to the coast (Howarth et al. (1996) Biogeochemistry 35:75–139; Jordan and Weller (1996) Bioscience 46:655–664). Global estimates of nitrogen export to coasts have been taken to be 25% of watershed input, based largely on northeastern U.S. observations (Galloway et al. (2004) Biogeochemistry 70:153–226; Boyer et al. (2006) Global Biogeochem Cycle 20:Art. No. GB1S91). We applied the N budgeting methodology developed for the International SCOPE Nitrogen project (Howarth et al. (1996) Biogeochemistry 35:75–139; Boyer et al. (2002) Biogeochemistry 57:137–169) to 12 watersheds in the southeastern U.S., and compared them with estimates of N export for 16 watersheds in the northeastern U.S. (Boyer et al. (2002) Biogeochemistry 57:137–169). In southeastern watersheds, average N export was only 9% of input, suggesting the need for downward revision of global estimates. The difference between northern and southern watersheds is not a function of the absolute value of N inputs, which spanned a comparable range and were positively related to export in both cases. Rather, the proportion of N exported was significantly related to average watershed temperature (% N export = 58.41 e−0.11 * temperature; R 2 = 0.76), with lower proportionate nitrogen export in warmer watersheds. In addition, we identified a threshold in proportionate N export at 38°N latitude that corresponds to a reported breakpoint in the rate of denitrification at 10–12°C. We hypothesize that temperature, by regulating denitrification, results in increased proportionate N export at higher latitudes. Regardless of the mechanism, these observations suggest that temperature increases associated with future climate change may well reduce the amount of nitrogen that reaches estuaries, which will have implications for coastal eutrophication.


Climate change Denitrification Eutrophication Nitrogen budgets Proportionate nitrogen export Temperature Watersheds 



We thank E. W. Boyer, R. W. Howarth, K. A. Payne, J. E. Sheldon, B. Binder, A. B. Burd, and A. E. Giblin for useful discussions and technical advice, J. T. Hollibaugh, L. R. Pomeroy, and R. W. Howarth for comments on an earlier version of this manuscript, and K. Lajtha and J. Schimel for their editorial support. Financial support for this work was provided by the Environmental Protection Agency (STAR Grant R830882) and the Georgia Coastal Ecosystems LTER Project (NSF Award OCE 99–82133).


  1. Addy K, Gold A, Nowicki B, McKenna J, Stolt M, Groffman P (2005) Denitrification capacity in a subterranean estuary below a Rhode Island fringing marsh. Estuaries 28:896–908CrossRefGoogle Scholar
  2. Ambus P (1993) Control of denitrification enzyme activity in a streamside soil. FEMS Microb Ecol 102:225–234CrossRefGoogle Scholar
  3. Battaglin WA, Goolsby DA (1994) Spatial data in geographic information system format on agricultural chemical use, land use, and cropping practices in the United States (USGS Water Resources Investigations Report 94-4176;
  4. Battye R, Battye W, Overcash C, Fudge S (1994) Development and selection of ammonia emission factors (Final Report prepared by EC/R Incorporated for EPA Atmospheric Research Assessment Lab, EPA Contract Number 68-D3-0034)Google Scholar
  5. Boring LR, Swank WT (1984) The role of black locust (Robinia pseudo-acacia) in forest succession. J Ecol 72:749–766CrossRefGoogle Scholar
  6. Bouwman AF, Van Drecht G, Knoop JM, Beusen AHW, Meinardi CR (2005) Exploring changes in river nitrogen export to the world’s oceans. Global Biogeochem Cycle 19:Art. No. GB1002Google Scholar
  7. Boyer EW, Goodale CL, Jaworski NA, Howarth RW (2002) Anthropogenic nitrogen sources and relationships to riverine nitrogen export in the northeastern U.S.A. Biogeochemistry 57:137–169CrossRefGoogle Scholar
  8. Boyer EW, Howarth RW, Galloway JN, Dentener FJ, Green PA, Vörösmarty CJ (2006) Riverine nitrogen export from the continents to the coasts. Global Biogeochem Cycle 20:Art. No. GB1S91Google Scholar
  9. Bricker SB, Clement CG, Pirhalla DE, Orlando SP, Farrow DRG (1999) National Estuarine Eutrophication Assessment. Effects of nutrient enrichment in the nation’s estuaries. NOAA-NOS Special Projects Office, Silver Spring, MDGoogle Scholar
  10. Caraco NF, Cole JJ, Likens GE, Lovett GM, Weathers KC (2003) Variation in NO3 export from flowing waters of vastly different sizes: does one model fit all? Ecosystems 6:344–352CrossRefGoogle Scholar
  11. Carpenter SR, Caraco NF, Correll DL, Howarth RW, Sharpley AN, Smith VH (1998) Nonpoint pollution of surface waters with phosphorus and nitrogen. Ecol Appl 8:559–568CrossRefGoogle Scholar
  12. Dumont E, Harrison JA, Kroeze C, Bakker EJ, Seitzinger SP (2005) Global distribution and sources of dissolved inorganic nitrogen export to the coastal zone: Results from a spatially explicit, global model. Global Biogeochem Cycle 19:Art. No. GB4S02Google Scholar
  13. Focht DD, Verstraete W (1977) Biochemical ecology of nitrification and denitrification. Adv Microb Ecol 1:135–214Google Scholar
  14. Galloway JN, Dentener FJ, Capone DG, Boyer EW, Howarth RW, Seitzinger SP, Asner GP, Cleveland CC, Green PA, Holland EA et al (2004) Nitrogen cycles: past, present, and future. Biogeochemistry 70:153–226CrossRefGoogle Scholar
  15. Garrow JS, James WPT, Ralph A (eds) (2000) Human nutrition and dietetics. Churchill Livingstone, Edinburgh, 900 ppGoogle Scholar
  16. Goodale CL, Lajtha K, Nadelhoffer KJ, Boyer EW, Jaworski NA (2002) Forest nitrogen sinks in large eastern U.S watersheds: estimates from forest inventory and an ecosystem model. Biogeochemistry 57/58:239–266CrossRefGoogle Scholar
  17. Green PA, Vörösmarty CJ, Meybeck M, Galloway JN, Peterson BJ, Boyer EW (2004) Preindustrial and contemporary fluxes of nitrogen through rivers: a global assessment based on typology. Biogeochemistry 68:71–105CrossRefGoogle Scholar
  18. Heichel GH, Barnes DK, Vance CP, Henjum KI (1984) N2 fixation, and N and dry matter partitioning during a 4-year alfalfa stand. Crop Sci 24:811–815CrossRefGoogle Scholar
  19. Hénault C, Germon JC (2000) NEMIS, a predictive model of denitrification on the field scale. Eur J Soil Sci 51:257–270CrossRefGoogle Scholar
  20. Holtan-Hartwig L, Dörsch P, Bakken LR (2002) Low temperature control of soil denitrifying communities: kinetics of N2O production and reduction. Soil Biol Biochem 34:1797–1806CrossRefGoogle Scholar
  21. Howarth RW, Billen G, Swaney D, Townsend A, Jaworski N, Lajtha K, Downing JA, Elmgren R, Caraco N, Jordan T et al (1996) Regional nitrogen budgets and riverine N & P fluxes for the drainages to the North Atlantic Ocean: natural and human influences. Biogeochemistry 35:75–139CrossRefGoogle Scholar
  22. Howarth RW, Boyer EW, Pabich WJ, Galloway JN (2002) Nitrogen use in the United States from 1961–2000 and potential future trends. Ambio 31:88–96CrossRefGoogle Scholar
  23. Howarth RW, Swaney DP, Boyer EW, Marino R, Jaworski N, Goodale C (2006) The influence of climate on average nitrogen export from large watersheds in the northeastern United States. Biogeochemistry 79:163–186CrossRefGoogle Scholar
  24. Hurd TM, Raynal DJ, Schwintzer CR (2001) Symbiotic N2 fixation of Alnus incana spp. Rugosa in shrub wetlands of the Adirondack Mountains, New York, U.S.A. Oecologia 126:94–103CrossRefGoogle Scholar
  25. Houghton JT, Ding Y, Griggs DJ, Noguer M, van der Linden PJ, Dai X, Maskell K, Johnson CA (eds) (2001) Climate Change 2001: the Scientific Basis. Cambridge Univ. Press, Cambridge, UKGoogle Scholar
  26. Jordan TE, Weller DE (1996) Human contributions to terrestrial nitrogen flux. Bioscience 46:655–664CrossRefGoogle Scholar
  27. Lander CH, Moffitt D (1996) Nutrient use in cropland agriculture (Commercial Fertilizers and Manure): Nitrogen and Phosphorus. Working Paper 14, RCAIII, NRCS, United States Department of AgricultureGoogle Scholar
  28. Malhi SS, McGill WB, Nybord M (1990) Nitrate losses in soils: effect of temperature, moisture, and substrate concentration. Soil Biol Biochem 22:733–737CrossRefGoogle Scholar
  29. Moore MV, Pace ML, Mather JR, Murdoch PS, Howarth RW, Folt CL, Chen CY, Hemond HF, Flebbe PA, Driscoll CA (1997) Potential effects of climate change on freshwater ecosystems of the New England/Mid-Atlantic region. Hydrol Proc 11:925–947CrossRefGoogle Scholar
  30. National Atlas of the United States. (2006) Major dams of the United States. National Atlas of the United States, Reston, VAGoogle Scholar
  31. National Atmospheric Deposition Program/National Trends Network (NRSP-3; 2005; NADP Program Office, Illinois State Water Survey, 2204 Griffith Dr., Champaign, IL 61820)Google Scholar
  32. National Research Council. (2000) Clean coastal waters: understanding and reducing the effects of nutrient pollution. National Academy Press, Washington, DCGoogle Scholar
  33. Neff JC, Holland EA, Dentener FJ, McDowell WH, Russell KM (2002) The origin, composition and rates of organic nitrogen deposition: a missing piece of the nitrogen cycle? Biogeochemistry 57:99–136CrossRefGoogle Scholar
  34. Parfitt RL, Schipper LA, Baisden WT, Elliott AH (2006) Nitrogen inputs and outputs for New Zealand in 2001 at national and regional scales. Biogeochemistry 80:71–88CrossRefGoogle Scholar
  35. Pfennig KS, McMahon PB (1997) Effect of nitrate, organic carbon, and temperature on potential denitrification rates in nitrate-rich riverbed sediments. J Hydrol 187:283–295CrossRefGoogle Scholar
  36. Schaefer SC (2006) Nutrient budgets for watersheds on the southeastern Atlantic coast of the United States: temporal and spatial variation. M.S. Thesis, University of GeorgiaGoogle Scholar
  37. Seitzinger SP (1990) Denitrification in aquatic sediments. In: Revsbech NP, Sorensen J (eds) Denitrification in soil, sediment. Plenum Press, New York, pp 301–322Google Scholar
  38. Seitzinger SP, Styles RV, Boyer EW, Billen G, Howarth RW, Mayer B, Van Breemen N (2002) Nitrogen retention in rivers: model development and application to watersheds in the northeastern U.S.A. Biogeochemistry 57/58:199–237CrossRefGoogle Scholar
  39. Seitzinger S, Harrison JA, Böhlke JK, Bouwman AF, Lowrance R, Peterson B, Tobias C, Van Drecht G (2006) Denitrification across landscapes and waterscapes: a synthesis. Ecol Appl 16:2064–2090CrossRefGoogle Scholar
  40. Smil V (1999) Nitrogen in crop production: An account of global flows. Global Biogeochem Cycle 13:647–662CrossRefGoogle Scholar
  41. Smith SV, Swaney DP, Talaue-McManus L, Bartley JD Sandhei PT, McLaughlin CJ, Dupra VC, Crossland CJ, Buddemeier RW, Maxwell BA, Wulff F (2003) Humans, hydrology, and the distribution of inorganic nutrient loading to the ocean. BioScience 53:235–245CrossRefGoogle Scholar
  42. Stanford G, Dzienia S, Van der Pol RA (1975) Effect of temperature on denitrification rates in soils. Soil Sci Soc Am Proc 39:867–870CrossRefGoogle Scholar
  43. Steeves P, Nebert D (1994) 1:250,000-scale Hydrologic Units of the United States. USGS Open-File Report 94–0236. United States Geologic Survey, Reston, VAGoogle Scholar
  44. Thornton PE, Running SW, White MA (1997) Generating surfaces of daily meteorological variables over large regions of complex terrain. J Hydrol 190:214–251CrossRefGoogle Scholar
  45. [USBoC] United States Bureau of the Census (1990) 1990 Census of Population: General population characteristics, United States (
  46. [USBoC] United States Bureau of the Census (2005) 1990 County and County Equivalent Areas (
  47. [USDA-FS] United States Department of Agriculture-Forest Service (2005) Forest Inventory and Analysis National Program (Arlington, VA;
  48. [USDA-NASS] United States Department of Agriculture—National Agricultural Statistics Service (1992) 1992 Census of Agriculture, Vol 1, Geographic Area Series (
  49. [USDA-NRCS] United States Department of Agriculture—Natural Resources Conservation Service (2005) PLANTS Database Crop Nutrient Tool (
  50. [USEPA] United States Environmental Protection Agency (1995) Clean Air Status and Trends Network (
  51. [USGS] United States Geological Survey (1999a) Georgia Land Cover Data Set (USGS EROS Data Center, Sioux Falls, SD;
  52. [USGS] United States Geological Survey (1999b) South Carolina Land Cover Data Set (USGS EROS Data Center, Sioux Falls, SD;
  53. [USGS] United States Geological Survey (1999c) Virginia Land Cover Data Set (USGS EROS Data Center, Sioux Falls, SD;
  54. [USGS] United States Geological Survey (1999d) “National Elevation Dataset” (EROS Data Center: Sioux Falls, SD;
  55. [USGS] United States Geological Survey (2000) North Carolina Land Cover Data Set (USGS EROS Data Center, Sioux Falls, SD;
  56. [USGS] United States Geological Survey (2005) National Water Information System (
  57. Van Breemen NA, Boyer EW, Goodale CL, Jaworski NA, Paustian K, Seitzinger SP, Lajtha K, Mayer B, Van Dam D, Howarth RW et al (2002) Where did all the nitrogen go? Fate of nitrogen inputs to large watersheds in the northeastern U.S.A. Biogeochemistry 57/58:267–293CrossRefGoogle Scholar
  58. Van Drecht G, Bouwman AF, Knoop JM, Beusen AHW, Meinardi CR (2003) Global modeling of the fate of nitrogen from point and nonpoint sources in soils, groundwater, and surface water. Glob Biogeochem Cycles 17:Art. No. GB4S06Google Scholar
  59. Van Horn HH (1998) Factors affecting manure quantity, quality, and use. In Proceedings of the mid-south ruminant nutrition conference, Dallas-Ft. Worth, May 7–8, 1998. Texas Animal Nutrition Council, pp 9–20Google Scholar
  60. Westermann P, Ahring BK (1987) Dynamics of methane production, sulfate reduction, and denitrification in a permanently waterlogged alder swamp. Appl Environ Microbiol 53:2554–2559Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  1. 1.Department of Marine SciencesUniversity of GeorgiaAthensUSA
  2. 2.Institute of EcologyUniversity of GeorgiaAthensUSA

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