, Volume 159, Issue 3, pp 571–581 | Cite as

Conservation of nitrogen increases with precipitation across a major grassland gradient in the Central Great Plains of North America

  • Rebecca L. McCulleyEmail author
  • Ingrid C. Burke
  • William K. Lauenroth
Ecosystem Ecology - Original Paper


Regional analyses and biogeochemical models predict that ecosystem N pools and N cycling rates must increase from the semi-arid shortgrass steppe to the sub-humid tallgrass prairie of the Central Great Plains, yet few field data exist to evaluate these predictions. In this paper, we measured rates of net N mineralization, N in above- and belowground primary production, total soil organic matter N pools, soil inorganic N pools and capture in resin bags, decomposition rates, foliar 15N, and N use efficiency (NUE) across a precipitation gradient. We found that net N mineralization did not increase across the gradient, despite more N generally being found in plant production, suggesting higher N uptake, in the wetter areas. NUE of plants increased with precipitation, and δ15N foliar values and resin-captured N in soils decreased, all of which are consistent with the hypothesis that N cycling is tighter at the wet end of the gradient. Litter decomposition appeared to play a role in maintaining this regional N cycling trend: litter decomposed more slowly and released less N at the wet end of the gradient. These results suggest that immobilization of N within the plant–soil system increases from semi-arid shortgrass steppe to sub-humid tallgrass prairie. Despite the fact that N pools increase along a bio-climatic gradient from shortgrass steppe to mixed grass and tallgrass prairie, this element becomes relatively more limiting and is therefore more tightly conserved at the wettest end of the gradient. Similar to findings from forested systems, our results suggest that grassland N cycling becomes more open to N loss with increasing aridity.


Grasslands Net nitrogen mineralization Nitrogen pools Nitrogen use efficiency Regional trends 



The Nature Conservancy, USDA-ARS, and Fort Hays State University generously provided access to the field sites. An NSF Dissertation Improvement Award (DEB 0073189) and the NSF Long-Term Ecological Research Program’s Shortgrass Steppe (DEB 9632852) and Konza Prairie sites funded the work. We thank: John Blair, Gene Kelly, and Jason Kaye for experimental and analytical advice; Mark Lindquist, Alan Knapp, John Greathouse, Karen Hickman, and the Van Slykes for logistical support; and Brian Ford, Dani-Ella Betz, Gene Kelly, Peter Adler, and Jim Nelson for volunteer field help. The manuscript was improved by the comments of several anonymous reviewers, for which we extend our thanks. The experiments conducted in this study comply with the current laws of the United States of America.


  1. Amundson R et al. (2003) Global patterns of the isotopic composition of soil and plant nitrogen. Global Biogeochem Cycles 17:1031CrossRefGoogle Scholar
  2. Aranibar JN et al. (2004) Nitrogen cycling in the soil-plant system along a precipitation gradient in the Kalahari sands. Global Change Biol 10:359–373CrossRefGoogle Scholar
  3. Augustine DJ, McNaughton SJ (2004) Temporal asynchrony in soil nutrient dynamics and plant production in a semiarid ecosystem. Ecosystems 7:829–840CrossRefGoogle Scholar
  4. Austin AT, Vitousek PM (1998) Nutrient dynamics on a precipitation gradient in Hawai’i. Oecologia 113:519–529CrossRefGoogle Scholar
  5. Austin AT et al. (2004) Water pulses and biogeochemical cycles in arid and semiarid ecosystems. Oecologia 141:221–235PubMedCrossRefGoogle Scholar
  6. Bardgett RD, Streeter TC, Bol R (2003) Soil microbies compete effectively with plants for organic-nitrogen inputs to temperate grasslands. Ecology 84:1277–1287CrossRefGoogle Scholar
  7. Barrett JE, Burke IC (2000) Potential nitrogen immobilization in grassland soils across a soil organic matter gradient. Soil Biol Biochem 32:1707–1716CrossRefGoogle Scholar
  8. Barrett JE, McCulley RL, Lane DR, Burke IC, Lauenroth WK (2002) Influence of climate variability on plant production and N-mineralization in the Central US grasslands. J Veg Sci 13:383–394CrossRefGoogle Scholar
  9. Binkley D, Hart SC (1989) The components of nitrogen availability assessments in forest soils. Adv Soil Sci 10:57–112Google Scholar
  10. Binkley D, Matson P (1983) Ion exchange resin bag method for assessing forest soil nitrogen availability. Soil Sci Soc Am J 47:1050–1052Google Scholar
  11. Blair JM (1997) Fire, N availability, and plant response in grasslands: a test of the transient maxima hypothesis. Ecology 78:2359–2368Google Scholar
  12. Blair JM, Seastedt TR, Rice CW, Ramundo RA (1998) Terrestrial nutrient cycling in tallgrass prairie, ch. 13. In: Knapp AK, Briggs JM, Hartnett DC, Collins SL (eds) Grassland dynamics: long-term ecological research in tallgrass prairie. Oxford University Press, New York, pp 222–243Google Scholar
  13. Bohm W (1979) Methods of studying root systems. Springer, BerlinGoogle Scholar
  14. Bontti EE et al. (2008) Litter decomposition in grasslands of Central North America (US Great Plains). Global Change Biol (in press)Google Scholar
  15. Booth MS, Stark JM, Rastetter EB (2005) Controls on nitrogen cycling in terrestrial ecosystems: a synthetic analysis of literature data. Ecol Monogr 75:139–157CrossRefGoogle Scholar
  16. Burke IC, Yonker CM, Parton WJ, Cole CV, Flach K, Schimel DS (1989) Texture, climate, and cultivation effects on soil organic matter content in U.S. grassland soils. Soil Sci Soc Am J 53:800–805Google Scholar
  17. Burke IC, Lauenroth WK, Parton WJ (1997) Regional and temporal variation in net primary production and nitrogen mineralization in grasslands. Ecology 78:1330–1340Google Scholar
  18. Burke IC et al. (1998) Plant–soil interactions in temperate grasslands. Biogeochemistry 42:121–143CrossRefGoogle Scholar
  19. Clark FE (1977) Internal cycling of 15nitrogen in shortgrass prairie. Ecology 58:1322–1333CrossRefGoogle Scholar
  20. Coupland RT (1992) Mixed Prairie. In: Coupland RT (ed) Natural grasslands: introduction and western hemisphere, vol 8A. Elsevier, Amsterdam, pp 151–182Google Scholar
  21. Dodd JL, Lauenroth WK (1979) Analysis of the response of a grassland ecosystem to stress. In: French N (ed) Perspectives in grassland ecology, vol Ecological Studies 32. Springer, New York, pp 43–58Google Scholar
  22. Epstein HE, Lauenroth WK, Burke IC, Coffin DP (1996) Ecological responses of dominant grasses along two climatic gradients in the Great Plains of the United States. J Veg Sci 7:777–788CrossRefGoogle Scholar
  23. Epstein HE, Lauenroth WK, Burke IC, Coffin DP (1997) Productivity patterns of C3 and C4 functional types in the U.S. Great Plains. Ecology 78:722–731Google Scholar
  24. Fisher FM, Whitford WG (1995) Field simulation of wet and dry years in the Chichuahuan desert: soil moisture, N mineralization and ion-exchange resin bags. Biol Fertil Soils 20:137–146CrossRefGoogle Scholar
  25. Gee GW, Bauder JW (1986) Particle size analysis. In: Klute A (ed) Methods of soil analysis. Part 1. Physical and mineralogical methods, 2nd edn. Agronomy Society of America, and Soil Science Society of America, Madison, pp 383–411Google Scholar
  26. Goering HK, van Soest P (1970) Forage fiber analyses. In: United States Department of Agriculture, Agricultural Research Service, Washington, DC, pp 1–20Google Scholar
  27. Handley LL et al. (1999) The 15N natural abundance (δ15 N) of ecosystem samples reflects measures of water availability. Aust J Plant Physiol 26:185–199CrossRefGoogle Scholar
  28. Hayes DC, Seastedt TR (1989) Nitrogen dynamics of soil water in burned and unburned tallgrass prairie. Soil Biol Biochem 21:1003–1007CrossRefGoogle Scholar
  29. Hook PB, Burke IC (1995) Evaluation of methods for estimating net nitrogen mineralization in a semiarid grassland. Soil Sci Soc Am J 59:831–837CrossRefGoogle Scholar
  30. Hook PB, Burke IC (2000) Biogeochemistry in a shortgrass landscape: control by topography, soil texture, and microclimate. Ecology 81:2686–2703Google Scholar
  31. Hook PB, Burke IC, Lauenroth WK (1991) Heterogeneity of soil and plant N and C associated with individual plants and openings in North American shortgrass steppe. Pl Soil 138:247–256CrossRefGoogle Scholar
  32. Hooper DU, Johnson L (1999) Nitrogen limitation in dryland ecosystems: responses to geographical and temporal variation in precipitation. Biogeochemistry 46:247–293Google Scholar
  33. Hunt HW, Reuss DE, Elliott ET (1999) Correcting estimates of root chemical composition for soil contamination. Ecology 80:702–707Google Scholar
  34. Johnson LC, Matchett JR (2001) Fire and grazing regulate belowground process in tallgrass prairie. Ecology 82:3377–3389Google Scholar
  35. Kaye JP, Hart SC (1997) Competition for nitrogen between plants and soil microorganisms. Trends Ecol Evol 12:139–143Google Scholar
  36. Kelly RH, Parton WJ, Hartman MD, Stretch LK, Ojima DS, Schimel DS (2000) Intra-annual and interannual variability of ecosystem processes in shortgrass steppe. J Geophys Res 105:20093–20100CrossRefGoogle Scholar
  37. Lauenroth WK (2000) Methods of estimating belowground net primary production. In: Sala OE, Jackson RB, Mooney HA, Howarth RW (eds) Methods in ecosystem science. Springer, New York, pp 58–71Google Scholar
  38. Lauenroth WK, Milchunas D (1992) Short-grass steppe. In: Coupland RT (ed) Natural grasslands: introduction and western hemisphere, vol 8A. Elsevier, Amsterdam, pp 183–226Google Scholar
  39. Lauenroth WK, Dodd JL, Sims PL (1978) The effects of water- and nutrient-induced stresses on plant community structure in a semiarid grassland. Oecologia 36:211–222CrossRefGoogle Scholar
  40. Lauenroth WK, Burke IC, Gutmann MP (1999) The structure and function of ecosystems in the Central North American Grassland Region. Great Plains Res 9:223–259Google Scholar
  41. Lipson DA, Nasholm T (2001) The unexpected versatility of plants: organic nitrogen use and availability in terrestrial ecosystems. Oecologia 128:305–316CrossRefGoogle Scholar
  42. McCulley RL, Burke IC (2004) Microbial community composition across the Great Plains: Landscape versus regional variability. Soil Sci Soc Am J 68:106–115Google Scholar
  43. McCulley RL, Burke IC, Nelson JA, Lauenroth WK, Knapp AK, Kelly EF (2005) Regional patterns in carbon cycling across the Great Plains of North America. Ecosystems 8:106–121CrossRefGoogle Scholar
  44. Milchunas D, Lauenroth WK (2001) Belowground primary production by carbon isotope decay and long-term root biomass dynamics. Ecosystems 4:139–150CrossRefGoogle Scholar
  45. Murphy K et al. (2002) Regional analysis of litter quality in the central grassland region of North America. J Veg Sci 13:395–402CrossRefGoogle Scholar
  46. Nadelhoffer KJ, Fry B (1994) Nitrogen isotope studies in forested ecosystems. In: Lathja K, Michener RH (eds) Stable isotopes in ecology and environmental science. Blackwell, Oxford, pp 22–44Google Scholar
  47. Nelson DW, Sommers LE (1996) Total Carbon, Organic Carbon, and Organic Matter. In: Sparks DL et al. (ed) Methods of soil analysis. Part 3, vol SSSA book series: 5. ASA, SSSA, Madison, pp 961–1010Google Scholar
  48. Olson JS (1963) Energy storage and the balance of producers and decomposers in ecological systems. Ecology 44:322–331CrossRefGoogle Scholar
  49. Owensby CE, Hyde RM, Anderson KL (1970) Effects of clipping and supplemental nitrogen and water on loamy upland bluestem range. J Range Manage 23:341–346CrossRefGoogle Scholar
  50. Parton WJ, Schimel DS, Cole CV, Ojima DS (1987) Analysis of factors controlling soil organic matter levels in Great Plains grasslands. Soil Sci Soc Am J 51:1173–1179Google Scholar
  51. Parton WJ et al. (2007) Global-scale similarities in nitrogen release patterns during long-term decomposition. Science 315:361–364PubMedCrossRefGoogle Scholar
  52. Raab TK, Lipson DA, Monson RK (1999) Soil amino acid utilization among species of the Cyperaceae: plant and soil processes. Ecology 80:2408–2419Google Scholar
  53. Raison RJ, Connell MJ, Khanna PK (1987) Methodology for studying fluxes of soil mineral-N in situ. Soil Biol Biochem 19:521–530CrossRefGoogle Scholar
  54. Risser PG, Parton WJ (1982) Ecosystem analysis of the tallgrass prairie: nitrogen cycle. Ecology 63:1342–1351CrossRefGoogle Scholar
  55. Sala OE, Parton WJ, Joyce LA, Lauenroth WK (1988) Primary production of the Central Grassland Region of the United States. Ecology 69:40–45CrossRefGoogle Scholar
  56. SAS (1996) SAS for Windows, version 6.11, CaryGoogle Scholar
  57. Schimel JP, Bennett J (2004) Nitrogen mineralization: challenges of a changing paradigm. Ecology 85:591–602CrossRefGoogle Scholar
  58. Seastedt TR, Briggs JM, Gibson DJ (1991) Controls on nitrogen limitation in tallgrass prairie. Oecologia 87:72–79CrossRefGoogle Scholar
  59. Seyfried MS et al. (2005) Ecohydrological control of deep drainage in arid and semiarid regions. Ecology 86:277–287CrossRefGoogle Scholar
  60. Silletti AM, Knapp AK (2000) Responses of the codominant grassland species Andropogon gerardii and Sorghastrum nutans to long-term manipulations of nitrogen and water. Am Midl Nat 145:159–167CrossRefGoogle Scholar
  61. Sims PL, Singh JS (1978) The structure and function of ten western North American grasslands. III. Net primary production, turnover and efficiencies of energy capture and water use. J Ecol 66:573–597CrossRefGoogle Scholar
  62. Turner CL, Blair JM, Schartz RJ, Neel JC (1997) Soil N and plant responses to fire, topography, and supplemental N in tallgrass prairie. Ecology 78:1832–1843CrossRefGoogle Scholar
  63. Vinton MA, Burke IC (1997) Contigent effects of plant species on soils along a regional moisture gradient in the Great Plains. Oecologia 110:393–402CrossRefGoogle Scholar
  64. Walvoord MA et al. (2003) A reservoir of nitrate beneath desert soils. Science 302:1021–1024PubMedCrossRefGoogle Scholar
  65. Zak DR et al. (1994) Plant production and soil microorganisms in late-successional ecosystems: a continental-scale study. Ecology 75:2333–2347CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Rebecca L. McCulley
    • 1
    • 5
    Email author
  • Ingrid C. Burke
    • 1
    • 2
    • 3
  • William K. Lauenroth
    • 1
    • 2
    • 4
  1. 1.Graduate Degree Program in EcologyColorado State UniversityFort CollinsUSA
  2. 2.Department of Forest, Range, and Watershed Stewardship, and Natural Resources Ecology LaboratoryColorado State UniversityFort CollinsUSA
  3. 3.Haub School and Ruckelshaus Institute of Environment and Natural ResourcesUniversity of WyomingLaramieUSA
  4. 4.Department of BotanyUniversity of WyomingLaramieUSA
  5. 5.Department of Plant and Soil Sciences, N-222D Agricultural Science NorthUniversity of KentuckyLexingtonUSA

Personalised recommendations