Changes in carbon balance after insect disturbance in Western U.S. forests

David JP Moore, University of Arizona, davidjpmoore@email.arizona.edu (Presenter)
Nicole A Trahan, University of Colorado, nicole.trahan@colorado.edu
Philip Wilkes, King's College London, phillip.wilkes@kcl.ac.uk
Tristan Quaife, University of Exeter, t.l.quaife@exeter.ac.uk
Ankur R Desai, University of Wisconsin, desai@aos.wisc.edu
Jose F Negron, US Forest Service, jnegron@fs.fed.us
Britton B Stephens, National Center for Atmospheric Research, stephens@ucar.edu
Elder Kelly, US Forest Service, kelder@fs.fed.us
Russell K Monson, University of Arizona, russmonson@email.arizona.edu

Mountain pine beetle outbreaks have infested more than 86 million hectares of forest in the U.S.A. since 2000. Using 8-year records of gross primary productivity (GPP) and respiration fluxes, and parallel disturbance chronosequences in two lodgepole pine forests in Colorado, we show that soil respiration sharply declines with GPP after tree mortality, reflecting the loss of autotrophic respiration and rhizodeposition. Three years post-disturbance, soil respiration rates recover before declining again, co-incident with a pulse of increased soil organic carbon, de-coupling respiration from concurrent GPP. The impacts of beetle outbreaks on the carbon cycle are likely more complex than previous estimates, and consideration of the dynamics of autotrophic and heterotropic substrate supply suggests that beetle-killed forests lose less carbon to the atmosphere than previously estimated.

Presentation Type:  Poster

Session:  Global Change Impact & Vulnerability   (Tue 11:30 AM)

Associated Project(s): 

• Related Activity

Poster Location ID: 237