About Us | Help Videos | Contact Us | Subscriptions
 

Abstract

 

This article in JEQ

  1. Vol. 36 No. 1, p. 91-100
     
    Received: June 16, 2006
    Published: Jan, 2007


    * Corresponding author(s): lsaito@cabnr.unr.edu
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2134/jeq2006.0233

Fire Effects on Stable Isotopes in a Sierran Forested Watershed

  1. Laurel Saito *a,
  2. Wally W. Millera,
  3. Dale W. Johnsona,
  4. Robert G. Quallsa,
  5. Louis Provencherb,
  6. Erin Carrolla and
  7. Peter Szameitatc
  1. a Dep. of Natural Resources and Environmental Science, Univ. of Nevada Reno, Mail Stop 186, 1000 Valley Road, Reno, NV 89512
    b The Nature Conservancy, One E. First St., Suite 1007, Reno, NV 89501
    c 1475 Folsom Street, #362, Boulder, CO 80302

Abstract

This study tested the hypothesis that stable C and N isotope values in surface soil and litter would be increased by fire due to volatilization of lighter isotopes. The hypothesis was tested by: (1) performing experimental laboratory burns of organic and mineral soil materials from a watershed at combinations of temperature ranging 100 to 600°C and duration ranging from 1 to 60 min; (2) testing field samples of upland soils before, shortly after, and 1 yr following a wildfire in the same watershed; and (3) testing field soil samples from a down-gradient ash/sediment depositional area in a riparian zone following a runoff event after the wildfire. Muffle furnace results indicated the most effective temperature range for using stable isotopes for tracing fire impacts is 200 to 400°C because lower burn temperatures may not produce strong isotopic shifts, and at temperatures ≥600°C, N and C content of residual material is too low. Analyses of field soil samples were inconclusive: there was a slightly significant effect of the wildfire on δ15N values in upland watershed analyses 1 yr postburn, while riparian zone analyses results indicated that δ13C values significantly decreased ∼0.71‰ over a 9 mo post-fire period (p = 0.015), and ash/sediment layer δ13C values were ∼0.65‰ higher than those in the A horizon. The lack of field confirmation may have been due to overall wildfire burn temperatures being <200°C and/or microbial recovery and vegetative growth in the field. Thus, the muffle furnace experiment supported the hypothesis, but it is as yet unconfirmed by actual wildfire field data.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2007. American Society of Agronomy, Crop Science Society of America, Soil Science SocietyASA, CSSA, SSSA