Biophysical controls on soil respiration in the dominant patch types of an old-growth, mixed-conifer forest

  • Authors: Ma, Siyan; Chen, Jiquan; Butnor, John R.; North, Malcolm; Euskirchen, Eugénie S.; Oakley, Brian
  • Publication Year: 2005
  • Publication Series: Miscellaneous Publication
  • Source: Forest Science 51(3):221-232

Abstract

Little is known about biophysical controls on soil respiration in California's Sierra Nevada old-growth, mixed-conifer forests. Using portable and automated soil respiration sampling units, we measured soil respiration rate (SRR) in three dominant patch types: closed canopy (CC), ceanothus-dominated patches (CECO), and open canopy (OC). SRR varied significantly among the patch types, ranging from 2.0 to 4.5 μmol m-2 s-1 and from 0.9 to 2.9 μmol m-2 s-1 during the 1999 and 2000 measuring periods, respectively, with the maximum in CECO and the minimum in OC. Multiple peaks of seasonal SRR were functions of soil temperature and moisture dynamics. The relationship between SRR and soil temperature switched from a positive to a negative correlation when soil moisture dropped from saturation to drought. Time lag, as a function of soil moisture, was included in an exponential model to assess the effects of soil moisture on SRR in this seasonal water-stressed ecosystem. The total soil C flux summed by an area-weighted average across all three patch types was 660 ± 163 g C m-2 from May to Oct. 2000. These results may be applicable to other water-stressed forests in the Mediterranean climate Lone, and have implications for the conservation of soil carbon.

  • Citation: Ma, Siyan; Chen, Jiquan; Butnor, John R.; North, Malcolm; Euskirchen, Eugénie S.; Oakley, Brian 2005. Biophysical controls on soil respiration in the dominant patch types of an old-growth, mixed-conifer forest. Forest Science 51(3):221-232
  • Keywords: Soil CO2, efflux, soil temperature, soil moisture, Sierra Nevada, California
  • Posted Date: April 1, 1980
  • Modified Date: August 22, 2006
  • 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.