Effects of prescribed fire in mixed oak forests of the southern Appalachians: forest floor, soil, and soil solution nitrogen responses

Abstract

We examined nutrient cycling responses to prescribed fire on three sub-mesic, mixed-oak sites located in the Blue Ridge Physiographic province of the southern Appalachian Mountains: Alarka Laurel Branch (AL), Robin Branch (RB), and Roach Mill Branch (RM). Each study site was located within a sub-watershed that drained a first order stream. Our objective was to quantify the effects of prescribed burning on forest floor mass, nitrogen and carbon pools; and soil and soil water available nitrogen. Each site included a burned and unburned control area; both burned and control areas were sampled before and after burning. Within each plot, we sampled forest floor mass, carbon and nitrogen, soil and soil solution nitrate (NO3-N) and ammonium (NH4-N) concentrations before and after the prescribed burns. All prescribed fires were conducted in the dormant season and were low to moderate intensity. All sites lost a significant amount of forest floor mass due to burning; 82 to 91% of the Oi layer and 26 to 46% of the Oe + Oa layer. Soil NH4-N concentrations increased in surface soils (0-5 cm) only, immediately after burning, but return to pre-burn levels by mid-summer. Burning had no measurable effect on soil solution inorganic nitrogen concentrations. Low levels of solution NO3-N and NH4-N after burning and no change in stream NO3-N concentrations indicated that no inorganic nitrogen was lost from these sites.

  • Citation: Knoepp, Jennifer D.; Elliott, Katherine J.; Clinton, Barton D.; Vose, James M. 2009. Effects of prescribed fire in mixed oak forests of the southern Appalachians: forest floor, soil, and soil solution nitrogen responses. Journal of Torrey Botanical Society. 136(3): 380-391.
  • Keywords: fire, forest floor consumption, nitrogen, restoration.
  • Posted Date: September 22, 2009
  • Modified Date: October 19, 2009
  • Print Publications Are No Longer Available

    In an ongoing effort to be fiscally responsible, the Southern Research Station (SRS) will no longer produce and distribute hard copies of our publications. Many SRS publications are available at cost via the Government Printing Office (GPO). Electronic versions of publications may be downloaded, printed, and distributed.

    Publication Notes

    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
    • Our online publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS webmaster if you notice any errors which make this publication unusable.
    • To view this article, download the latest version of Adobe Acrobat Reader.