, Volume 11, Issue 1, pp 16–25 | Cite as

Nutrient Addition Prompts Rapid Destabilization of Organic Matter in an Arctic Tundra Ecosystem

  • Nicole S. Nowinski
  • Susan E. Trumbore
  • Edward A. G. Schuur
  • Michelle C. Mack
  • Gaius R. Shaver


Nutrient availability in the arctic is expected to increase in the next century due to accelerated decomposition associated with warming and, to a lesser extent, increased nitrogen deposition. To explore how changes in nutrient availability affect ecosystem carbon (C) cycling, we used radiocarbon to quantify changes in belowground C dynamics associated with long-term fertilization of graminoid-dominated tussock tundra at Toolik Lake, Alaska. Since 1981, yearly fertilization with nitrogen (N) and phosphorus (P) has resulted in a shift to shrub-dominated vegetation. These combined changes have altered the quantity and quality of litter inputs, the vertical distribution and dynamics of fine roots, and the decomposition rate of soil organic C. The loss of C from the deep organic and mineral soil has more than offset the C accumulation in the litter and upper organic soil horizons. In the litter and upper organic horizons, radiocarbon measurements show that increased inputs resulted in overall C accumulation, despite being offset by increased decomposition in some soil pools. To reconcile radiocarbon observations in the deeper organic and mineral soil layers, where most of the ecosystem C loss occurred, both a decrease in input of new root material and a dramatic increase of decomposition rates in centuries-old soil C pools were required. Therefore, with future increases in nutrient availability, we may expect substantial losses of C which took centuries to accumulate.


nitrogen phosphorus radiocarbon carbon dynamics tundra decomposition 


  1. ACIA. 2004. Impacts of a Warming Arctic–Arctic Climate Impact Assessment. London: Cambridge University PressGoogle Scholar
  2. Berg B. 1986. The influence of experimental acidification on nutrient release and decomposition rates of needle and root litter in the forest floor. For Ecol Manage 15:195–213CrossRefGoogle Scholar
  3. Berg B, Matzner E. 1997. Effect of N deposition on decomposition of plant litter and soil organic matter in forest systems. Environ Rev 5:1–25CrossRefGoogle Scholar
  4. Carreiro MM, Sinsabaugh RL, Repert DA, Parkhurst DF. 2000. Microbial enzyme shifts explain litter decay responses to simulated nitrogen deposition. Ecology 81:2359–2365Google Scholar
  5. Chapin FS, Shaver GR. 1996. Physiological and growth responses of arctic plants to a field experiment simulating climatic change. Ecology 77:822–840CrossRefGoogle Scholar
  6. Chapin FS, Shaver GR, Giblin AE, Nadelhoffer KJ, Laundre JA. 1995. Responses of Arctic Tundra to experimental and observed changes in climate. Ecology 76:694–711CrossRefGoogle Scholar
  7. Chapin FS, Sturm M, Serreze MC, McFadden JP, Key JR, Lloyd AH, McGuire AD, Rupp TS, Lynch AH, Schimel JP, Beringer J, Chapman WL, Epstein HE, Euskirchen ES, Hinzman LD, Jia G, Ping CL, Tape KD, Thompson CDC, Walker DA, Welker JM. 2005. Role of land-surface changes in Arctic summer warming. Science 310:657–660PubMedCrossRefGoogle Scholar
  8. Dormann CF, Woodin SJ. 2002. Climate change in the Arctic: using plant functional types in a meta-analysis of field experiments. Funct Ecol 16:4–17CrossRefGoogle Scholar
  9. Fahey TJ, Hughes JW. 1994. Fine-root dynamics in a northern hardwood forest ecosystem, hubbard brook experimental forest, Nh. J Ecol 82:533–548CrossRefGoogle Scholar
  10. Fierer N, Allen AS, Schimel JP, Holden PA. 2003. Controls on microbial CO2 production: a comparison of surface and subsurface soil horizons. Glob Chang Biol 9:1322–1332CrossRefGoogle Scholar
  11. Fog K. 1988. The effect of added nitrogen on the rate of decomposition of organic-matter. Biol Rev Camb Philos Soc 63:433–462CrossRefGoogle Scholar
  12. Frey SD, Knorr M, Parrent JL, Simpson RT. 2004. Chronic nitrogen enrichment affects the structure and function of the soil microbial community in temperate hardwood and pine forests. For Ecol Manage 196:159–171CrossRefGoogle Scholar
  13. Gaudinski JB, Trumbore SE, Davidson EA, Zheng SH. 2000. Soil carbon cycling in a temperate forest: radiocarbon-based estimates of residence times, sequestration rates and partitioning of fluxes. Biogeochemistry 51:33–69CrossRefGoogle Scholar
  14. Gaudinski JB, Trumbore SE, Davidson EA, Cook AC, Markewitz D, Richter DD. 2001. The age of fine-root carbon in three forests of the eastern United States measured by radiocarbon. Oecologia 129:420–429Google Scholar
  15. Haynes R. 1986. The decomposition process: mineralization, immobilization, humus formation, and degradation. In: Haynes R. (Ed.), Mineral Nitrogen in the Plant–Soil System. Orlando (FL): AcademicGoogle Scholar
  16. Hobbie SE. 1996. Temperature and plant species control over litter decomposition in Alaskan tundra. Ecol Monogr 66:503–522CrossRefGoogle Scholar
  17. Hobbie SE, Chapin FS. 1998. Response of tundra plant biomass, aboveground production, nitrogen, and CO2 flux to experimental warming. Ecology 79:1526–1544Google Scholar
  18. Hobbie SE, Miley TA, Weiss MS. 2002. Carbon and nitrogen cycling in soils from acidic and nonacidic tundra with different glacial histories in Northern Alaska. Ecosystems 5:761–774CrossRefGoogle Scholar
  19. Hobbie SE, Gough L, Shaver GR. 2005. Species compositional differences on different-aged glacial landscapes drive contrasting responses of tundra to nutrient addition. J Ecol 93:770–782CrossRefGoogle Scholar
  20. Horwath JL. 2007. Quantification and Spatial Assessment of High Arctic Soil Organic Carbon Storage in Northwest Greenland. Department of Earth and Space Sciences. Seattle: University of Washington. p. 296Google Scholar
  21. IPCC .2001. Climate change 2001: the scientific basis. In: Houghton JT, Ding Y, Griggs DJ, Noguer M, van der Linden PJ, Dai X, Maskell K, Johnson CA (Eds.), Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge (UK): Cambridge University Press, 881ppGoogle Scholar
  22. Jackson RB, Schenk HJ, Jobbagy EG, Canadell J, Colello GD, Dickinson RE, Field CB, Friedlingstein P, Heimann M, Hibbard K, Kicklighter DW, Kleidon A, Neilson RP, Parton WJ, Sala OE, Sykes MT. 2000. Belowground consequences of vegetation change and their treatment in models. Ecol Appl 10:470–483CrossRefGoogle Scholar
  23. Knorr M, Frey SD, Curtis PS. 2005. Nitrogen additions and litter decomposition: a meta-analysis. Ecology 86:3252–3257CrossRefGoogle Scholar
  24. Levin I, Kromer B. 2004. The tropospheric (CO2)–C-14 level in mid-latitudes of the Northern Hemisphere (1959–2003). Radiocarbon 46:1261–1272Google Scholar
  25. Mack MC, Schuur EAG, Bret-Harte MS, Shaver GR, Chapin FS. 2004. Ecosystem carbon storage in arctic tundra reduced by long-term nutrient fertilization. Nature 431:440–443PubMedCrossRefGoogle Scholar
  26. Majdi H, Pregitzer K, Moren AS, Nylund JE, Agren GI. 2005. Measuring fine root turnover in forest ecosystems. Plant Soil 276:1–8CrossRefGoogle Scholar
  27. McKane RB, Rastetter EB, Shaver GR, Nadelhoffer KJ, Giblin AE, Laundre JA, Chapin FS. 1997. Climatic effects on tundra carbon storage inferred from experimental data and a model. Ecology 78:1170–1187CrossRefGoogle Scholar
  28. Nadelhoffer KJ, Johnson L, Laundre J, Giblin AE, Shaver GR. 2002. Fine root production and nutrient content in wet and moist arctic tundras as influenced by chronic fertilization. Plant Soil 242:107–113CrossRefGoogle Scholar
  29. Nommik H, Vantras K. 1982. Retention and fixation of ammonium and ammonia in soils. In: Stevenson F. (Ed.), Nitrogen in Agricultural Soils. Madison (WI): ASA, CSSA, and SSSA, pp. 123–171Google Scholar
  30. Overpeck J, Hughen K, Hardy D, Bradley R, Case R, Douglas M, Finney B, Gajewski K, Jacoby G, Jennings A, Lamoureux S, Lasca A, MacDonald G, Moore J, Retelle M, Smith S, Wolfe A, Zielinski G. 1997. Arctic environmental change of the last four centuries. Science 278:1251–1256CrossRefGoogle Scholar
  31. Painter TJ. 1991. Lindow man, Tollund man and other peat-bog bodies––the preservative and antimicrobial action of Sphagnam, a reactive glycuronoglycan with tanning and sequestering properties. Carbohydr Polym 15:123–142CrossRefGoogle Scholar
  32. Perruchoud D, Joos F, Fischlin A, Hajdas I, Bonani G. 1999. Evaluating timescales of carbon turnover in temperate forest soils with radiocarbon data. Global Biogeochem Cycles 13:555–573CrossRefGoogle Scholar
  33. Serreze MC, Walsh JE, Chapin FS, Osterkamp T, Dyurgerov M, Romanovsky V, Oechel WC, Morison J, Zhang T, Barry RG. 2000. Observational evidence of recent change in the northern high-latitude environment. Clim Change 46:159–207CrossRefGoogle Scholar
  34. Shaver GR, Chapin FS. 1991. Production–biomass relationships and element cycling in contrasting Arctic vegetation types. Ecol Monogr 61:1–31CrossRefGoogle Scholar
  35. Shaver GR, Bret-Harte SM, Jones MH, Johnstone J, Gough L, Laundre J, Chapin FS. 2001. Species composition interacts with fertilizer to control long-term change in tundra productivity. Ecology 82:3163–3181Google Scholar
  36. Sinsabaugh RL, Carreiro MM, Repert DA. 2002. Allocation of extracellular enzymatic activity in relation to litter composition, N deposition, and mass loss. Biogeochemistry 60:1–24CrossRefGoogle Scholar
  37. Southon J, Santos G, Druffel-Rodriguez K, Druffel E, Trumbore S, Xu XM, Griffin S, Ali S, Mazon M. 2004. The Keck carbon cycle AMS laboratory, University of California, Irvine: Initial operation and a background surprise. Radiocarbon 46:41–49Google Scholar
  38. Stuiver M, Polach HA. 1977. Reporting of C-14 data––Discussion. Radiocarbon 19:355–363Google Scholar
  39. Sturm M, McFadden JP, Liston GE, Chapin FS, Racine CH, Holmgren J. 2001. Snow-shrub interactions in Arctic tundra: a hypothesis with climatic implications. J Clim 14:336–344CrossRefGoogle Scholar
  40. Sturm M, Schimel J, Michaelson G, Welker JM, Oberbauer SF, Liston GE, Fahnestock J, Romanovsky VE. 2005. Winter biological processes could help convert arctic tundra to shrubland. Bioscience 55:17–26CrossRefGoogle Scholar
  41. Sullivan P, Sommerkorn M, Rueth HM, Nadelhoffer KJ, Shaver GR, Welker JA. 2007. Climate and species affect fine root production with long-term fertilization in acidic tussock tundra near Toolik Lake, Alaska. Oecologia (in press)Google Scholar
  42. Tierney GL, Fahey TJ. 2002. Fine root turnover in a northern hardwood forest: a direct comparison of the radiocarbon and minirhizotron methods. Can J For Res Revue Canadienne De Recherche Forestiere 32:1692–1697CrossRefGoogle Scholar
  43. van Wijk MT, Clemmensen KE, Shaver GR, Williams M, Callaghan TV, Chapin FS, Cornelissen JHC, Gough L, Hobbie SE, Jonasson S, Lee JA, Michelsen A, Press MC, Richardson SJ, Rueth H. 2004. Long-term ecosystem level experiments at Toolik Lake, Alaska, and at Abisko, Northern Sweden: generalizations and differences in ecosystem and plant type responses to global change. Glob Chang Biol 10:105–123CrossRefGoogle Scholar
  44. Vogt K, Persson H. 1991. Measuring growth and development of roots. In: Lassoie J, Hinckley T. (Eds.), Techniques and Approaches in Forest Tree Ecophysiology. Boca Raton (FL): CRCGoogle Scholar
  45. Weintraub MN, Schimel JP. 2003. Interactions between carbon and nitrogen mineralization and soil organic matter chemistry in arctic tundra soils. Ecosystems 6:129–143CrossRefGoogle Scholar
  46. Weintraub MN, Schimel JP. 2005. Nitrogen cycling and the spread of shrubs control changes in the carbon balance of arctic tundra ecosystems. Bioscience 55:408–415CrossRefGoogle Scholar
  47. Woodin SJ. 1997. Effects of acid deposition on arctic vegetation. In: Woodin SJ, Marquiss M (Eds.), Ecology of Arctic Environments. Oxford (UK): Blackwell Science, pp. 219–240Google Scholar
  48. Xu XM, Trumbore SE, Zheng SH, Southon JR, McDuffee KE, Luttgen M, Liu JC. 2007. Modifying a sealed tube zinc reduction method for preparation of AMS graphite targets: reducing background and attaining high precision. Nucl Instrum Methods Phys Res B Beam Interact Mater Atoms 259:320–329CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Nicole S. Nowinski
    • 1
  • Susan E. Trumbore
    • 1
  • Edward A. G. Schuur
    • 2
  • Michelle C. Mack
    • 2
  • Gaius R. Shaver
    • 3
  1. 1.Department of Earth System ScienceUniversity of California—IrvineIrvineUSA
  2. 2.Department of BotanyUniversity of Florida—GainesvilleGainesvilleUSA
  3. 3.The Ecosystems CenterMarine Biological LabsWoods HoleUSA

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