, Volume 9, Issue 6, pp 967–976

Plant–Soil Feedbacks Contribute to the Persistence of Bromus inermis in Tallgrass Prairie



As invasive plants become a greater threat to native ecosystems, we need to improve our understanding of the factors underlying their success and persistence. Over the past 30 years, the C3 nonnative plant Bromus inermis (smooth brome) has been spreading throughout the central grasslands in North America. Invasion by this grass has resulted in the local displacement of natives, including the tallgrass species Panicum virgatum (switchgrass). To determine if factors related to resource availability and plant–soil interactions were conferring a competitive advantage on smooth brome, field plots were set up under varying nitrogen (N) levels. Plots composed of a 1:1 ratio of smooth brome and switchgrass were located in a restored tallgrass prairie and were randomly assigned one of the following three N levels: (a) NH4NO3 added to increase available N, (b) sucrose added to reduce available N, and (c) no additions to serve as control. In addition, soil N status, soil respiration rates, plant growth, and litter decomposition rates were monitored. Results indicate that by the 2nd year, the addition of sucrose significantly reduced available soil N and additions of NH4NO3 increased it. Further, smooth brome had greater tiller density, mass, and canopy interception of light on N-enriched soils, whereas none of these characteristics were stimulated by added N in the case of switchgrass. This suggests that smooth brome may have a competitive advantage on higher-N soils. Smooth-brome plant tissue also had a lower carbon–nitrogen (C:N) ratio and a higher decomposition rate than switchgrass and thus may cycle N more rapidly in the plant–soil system. These differences suggest a possible mechanism for the persistence of smooth brome in the tallgrass prairie: Efficient recycling of nutrient-rich litter under patches of smooth brome may confer a competitive advantage that enables it to persist in remnant or restored prairies. Increased N deposition associated with human activity and changing land use may play a critical role in the persistence of smooth brome and other N-philic exotic species.


invasion tallgrass prairie plant–soil feedback nitrogen smooth brome Bromus inermis carbon addition 


  1. Alpert P, Maron JL. 2000. Carbon addition as a counter measure against biological invasion by plants. Biol Inv 2:33–40CrossRefGoogle Scholar
  2. Baer SG, Blair JM, Collins SL, Knapp AK. 2003. Soil resources regulate productivity and diversity in newly established tallgrass prairie. Ecology 84:724–35Google Scholar
  3. Baer SG, Blair JM, Collins SL, Knapp AK. 2004. Plant community responses to resource availability and heterogeneity during restoration. Oecologia 139:617–29PubMedCrossRefGoogle Scholar
  4. Blair JM. 1997. Fire, N availability and plant response in grasslands: a test of the transient maxima hypothesis. Ecology 78:2539–68.CrossRefGoogle Scholar
  5. Blumenthal DM, Jordan NR, Russelle MP. 2003. Soil carbon addition controls weeds and facilitates prairie restoration. Ecol Appl 13:605–15Google Scholar
  6. Boettcher JF, Bragg TB, Sutherland DM. 1993. Floristic diversity in ten tallgrass prairie remnants of eastern Nebraska. Trans Nebr Acad Sci 20:33–40Google Scholar
  7. Bowman WD, Steltzer H, Rosenstiel TN, Cleveland CC, Meier CL. 2004. Litter effects of two co-occurring alpine species on plant growth, microbial activity and immobilization of nitrogen. Oikos 104:336–44CrossRefGoogle Scholar
  8. Bragg TB. 1978. Allwine Prairie Preserve: a reestablished bluestem grassland research area. In: Glenn-Lewin DC, Landers RQ, editors. Proceedings of the Fifth Midwest Prairie Conference, Iowa State University, Iowa, USA. p 114–9Google Scholar
  9. Butterfield C, Stubbendieck J, Stumpf J. 1996. Species abstracts of highly disruptive exotic plants. Jamestown (ND): Northern Prairie Wildlife Research Center Home Page. Available online at: (ver. 16JUL97)
  10. Carlson IT, Newell LC. 1985. Smooth bromegrass. In: Heath ME, Barnes RF, Metcalfe DS, editors. Forages: the science of grassland agriculture. 4th ed. Ames (IA): Iowa State University Press. p 198–206Google Scholar
  11. Corbin JD, D’Antonio CM. 2004. Can carbon addition increase competitiveness of native grasses? A case study from California. Restor Ecol 12:36–43CrossRefGoogle Scholar
  12. D’Antonio C, Vitousek PM. 1992. Biological invasions by exotic grasses, the grass/fire cycle, and global change. Annu Rev Ecol Syst 23:63–87.Google Scholar
  13. Dill TO, Waller SS, Vogel KP, Gates RN, Stroup WW. 1986. Renovation of seeded warm-season pastures with atrazine. J Range Manage 39:72–75Google Scholar
  14. Ehrenfeld JG. 2003. Effects of exotic plant invasions on soil nutrient cycling processes. Ecosystems 6:503–23CrossRefGoogle Scholar
  15. Galloway JN, Dentener FJ, Capone DG, Boyer EW, Howarth RW, Seitzinger SP, Asner GP, et al. 2004. Nitrogen cycles: past present and future. Biogeochemistry 70:153–226CrossRefGoogle Scholar
  16. Huenneke LF, Hamburg SP, Koide R, Mooney HA, Vitousek PM. 1990. Effects of soil resources on plant invasion and community structure in Californian serpentine grassland. Ecology 71:478–91CrossRefGoogle Scholar
  17. Knapp AK, Seastedt TR. 1986. Detritus accumulation limits productivity in tallgrass prairie. BioScience 36:662–8CrossRefGoogle Scholar
  18. Knapp AK, Briggs JM, Blair JM, Turner CL. 1998. Patterns and controls of aboveground primary production in tallgrass prairie. In: Knapp AK, Briggs JM, Hartnett DC, Collins SC, editors. Grassland dynamics: long-term ecological research in tallgrass prairie. New York: Oxford University Press. p 193–221Google Scholar
  19. Larson DL, Anderson PJ, Newton W. 2001. Alien plant invasion in mixed-grass prairie: effects of vegetation type and anthropogenic disturbance. Ecol Appl 11:128–41Google Scholar
  20. Mack RN, Simberloff D, Lonsdale WM, Evans H, Clout M, Bazazz FA. 2000. Biotic invasions: causes, epidemiology, global consequences and control. Ecol Appl 10:689–710Google Scholar
  21. Maron JL, Connors PG. 1996. A native nitrogen-fixing shrub facilitates weed invasion. Oecologia 105:302–312CrossRefGoogle Scholar
  22. Milchunas DG, Lavenroth WK. 1995. Inertia in plant community structure: State changes after cessation of nutrient-enrichment stress. Oecologia 5:452–458Google Scholar
  23. Miller DA. 1984. Forage crops. New York: McGraw-HillGoogle Scholar
  24. Monaco TM, Johnson DA, Norton JM, Jones TA, Connors KJ, Norton JB, Redinbaugh MB. 2003. Contrasting responses of intermountain west grasses to soil nitrogen. J Range Manage 56:282–90.Google Scholar
  25. [NADP] National Atmospheric Deposition Program (NRSP-3). 2005. Illinois State water survey. Champaign (IL): NADPGoogle Scholar
  26. National Invasive Species Council. 2001. Meeting the invasive species challenge: national invasive species management plan. Washington (DC): US Government Printing Office. 89 pGoogle Scholar
  27. Paschke M, McLendon WT, Redente EF. 2000. Nitrogen availability and old-field succession in a shortgrass steppe. Ecosystems 3:144–58.CrossRefGoogle Scholar
  28. Paul EA, Harris D, Klug MJ, Ruess RW. 1999. The determination of microbial biomass. New York: Oxford University Press. p 258–271Google Scholar
  29. Reever Morghan KJ, Seastedt TR. 1999. Effects of soil nitrogen reduction on nonnative plants in restored grasslands. Restor Ecol 7:51–5CrossRefGoogle Scholar
  30. Reich PB, Tilman D, Craine J, Ellsworth D, Tjoelker MG, Knops J, Wedin D, et al. 2001. Do species and functional groups differ in acquisition and use of C, N and water under varying atmospheric CO2 and N availability regimes? A field test with 16 grassland species. New Phytol 150:435–48CrossRefGoogle Scholar
  31. Reich PB, Buschena C, Tjoelker MG, Wrage K, Knops J, Tilman D, Machado JL. 2003. Variation in growth rate and ecophysiology among 34 grassland and savanna species under contrasting N supply: a test of functional group differences. New Phytol 157:617–31CrossRefGoogle Scholar
  32. Robertson GP, Wedin D, Groffman PM, Blair JM, Holland EA, Nadelhoffer KJ, Harris D. 1999. Soil carbon and nitrogen availability: nitrogen mineralization, nitrification, and soil respiration potentials. In: Robertson GP, Coleman DC, Bledsoe CS, Sollins P, Eds. Standard Soil methods for long-term ecological research. New York: Oxford University Press. p 258–271Google Scholar
  33. Schacht WH, Stubbendieck J, Bragg TB, Smart AJ, Doran JW. 1996. Soil quality response of reestablished grasslands to mowing and burning. J Range Manage 49:458–63Google Scholar
  34. Schimel DS. 1986. Carbon and nitrogen turnover in adjacent grassland and cropland ecosystems. Biogeochemistry 2:345–357CrossRefGoogle Scholar
  35. Smith VH, Tilman GD, Nekola JC. 1999. Eutrophication: impacts of excess nutrient inputs on freshwater, marine, and terrestrial ecosystems. Environ Pollut 100:179–96PubMedCrossRefGoogle Scholar
  36. Snyder JD, Trofymow JA. 1984. A rapid, accurate wet oxidation diffusion procedure for determining organic and inorganic carbon in plant and soil samples. Comm Soil Sci Plant Anal 15:587–97CrossRefGoogle Scholar
  37. Steinauer EM, Collins SL. 1995. Effects of urine deposition on small-scale patch structure in prairie vegetation. Ecology 76:1195–205CrossRefGoogle Scholar
  38. Stillwell MA. 1983. Effects of bovine urinary nitrogen on the nitrogen cycle of the shortgrass prairie [dissertation]. Fort Collins (CO): Colorado State UniversityGoogle Scholar
  39. Stubbendieck J, Hatch SL, Butterfield CH. 1992. North American range plants. 4th Ed. Lincoln (NE): University of Nebraska Press. 493 pGoogle Scholar
  40. Suding KN, LeJeune KK, Seastedt TR. 2004. Competitive impacts and responses of an invasive weed: dependencies on nitrogen and phosphorus availability. Oecologia 141:526–35PubMedCrossRefGoogle Scholar
  41. Suding KN, Collins SL, Gough L, Clark C, Cleland EE, Gross KL, Milchunas DG, et al. 2005. Functional- and abundance-based mechanisms explain diversity loss due to N fertilization. Proc Nat’ Acad Sci USA 102:4387–92CrossRefGoogle Scholar
  42. Vinton MA, Burke IC. 1995. Interactions between individual plant species and soil nutrient status in shortgrass-steppe. Ecology 76:1116–33CrossRefGoogle Scholar
  43. Vitousek PM, Aber JD, Howarth RW, Likens GE, Matson PA, Schindler DW, Schlesinger WH, et al. 1997. Human alterations of the global nitrogen cycle: sources and consequences. Ecol Appl 7:737–50.Google Scholar
  44. Waller SS, Schmidt DK. 1983. Improvement of eastern Nebraska tallgrss range using atrazine or glyphosate. J Range Manage 36:87–90Google Scholar
  45. Wedin DA, Tilman D. 1990. Species effects on nutrient cycling: a test with perennial grasses. Oecologia 84:433–41Google Scholar
  46. Wedin DA, Tilman D. 1996. Influence of nitrogen loading and species composition on the carbon balance of grasslands. Science 274:1720–3PubMedCrossRefGoogle Scholar
  47. Weaver JE. 1954. North American prairie. Lincoln (NE): Johnsen. 348 pGoogle Scholar
  48. Weaver JE. 1965. Native vegetation of Nebraska. Lincoln (NE): University of Nebraska Press. 185 pGoogle Scholar
  49. Weaver JE. 1968. Prairie plants and their environment: a fifty-year study in the Midwest. Lincoln (NE): University of Nebraska Press. 276 pGoogle Scholar
  50. Weaver JE, Fitzpatrick TJ. 1934. The prairie. Ecol Monogr 4:109–295CrossRefGoogle Scholar
  51. Willson GD, Stubbendieck J. 1996. Suppression of smooth brome by atrazine, mowing and fire. Prairie Nat 28:13–20Google Scholar
  52. Willson GD, Stubbendieck J. 2000. A provisional model for smooth brome management in degraded tallgrass prairie. Ecol Restor 18:34–8Google Scholar
  53. Wilson SD, Gerry AK. 1995. Strategies for mixed-grass prairie restoration: herbicide, tilling and nitrogen manipulation. Restor Ecol 3:290–8CrossRefGoogle Scholar
  54. Zink TA, Allen MF. 1998. The effects of organic amendments on a restoration of a disturbed coastal sage scrub habitat. Restor Ecol 6:52–8CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  1. 1.Department of BiologyCreighton UniversityOmahaUSA
  2. 2.Ecology, Evolution, and Conservation Biology Graduate Group, Natural Resources and Environmental ScienceUniversity of Nevada-RenoRenoUSA

Personalised recommendations