Biogeochemistry

, Volume 24, Issue 2, pp 67–84

Long- and short-term effects of fire on nitrogen cycling in tallgrass prairie

  • Dennis S. Ojima
  • D. S. Schimel
  • W. J. Parton
  • C. E. Owensby
Article

DOI: 10.1007/BF02390180

Cite this article as:
Ojima, D.S., Schimel, D.S., Parton, W.J. et al. Biogeochemistry (1994) 24: 67. doi:10.1007/BF02390180

Abstract

Fires in the tallgrass prairie are frequent and significantly alter nutrient cycling processes. We evaluated the short-term changes in plant production and microbial activity due to fire and the long-term consequences of annual burning on soil organic matter (SOM), plant production, and nutrient cycling using a combination of field, laboratory, and modeling studies. In the short-term, fire in the tallgrass prairie enhances microbial activity, increases both above-and belowground plant production, and increases nitrogen use efficiency (NUE). However, repeated annual burning results in greater inputs of lower quality plant residues causing a significant reduction in soil organic N, lower microbial biomass, lower N availability, and higher C:N ratios in SOM. Changes in amount and quality of below-ground inputs increased N immobilization and resulted in no net increases in N availability with burning. This response occurred rapidly (e.g., within two years) and persisted during 50 years of annual burning. Plant production at a long-term burned site was not adversely affected due to shifts in plant NUE and carbon allocation. Modeling results indicate that the tallgrass ecosystem responds to the combined changes in plant resource allocation and NUE. No single factor dominates the impact of fire on tallgrass plant production.

Key words

carbonfireimmobilizationmineralizationnitrogen use efficiencysoil organic mattertallgrass prairie

Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • Dennis S. Ojima
    • 1
  • D. S. Schimel
    • 2
  • W. J. Parton
    • 3
  • C. E. Owensby
    • 4
  1. 1.Natural Resource Ecology LaboratoryColorado State UniversityFort Collins
  2. 2.Climate System Modeling Program, NCARBoulder
  3. 3.Department of Range Science, Natural Resource Ecology LaboratoryColorado State UniversityFort Collins
  4. 4.Department of AgronomyKansas State UniversityManhattanUSA