Carbon isotopic composition of forest soil respiration in the decade following bark beetle and stem girdling disturbances in the Rocky Mountains

Gregory E. Maurer, Allison M. Chan, Nicole A. Trahan, David J.P. Moore, David R. Bowling

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

Bark beetle outbreaks are widespread in western North American forests, reducing primary productivity and transpiration, leading to forest mortality across large areas and altering ecosystem carbon cycling. Here the carbon isotope composition (δ13C) of soil respiration (δJ) was monitored in the decade after disturbance for forests affected naturally by mountain pine beetle infestation and artificially by stem girdling. The seasonal mean δJ changed along both chronosequences. We found (a) enrichment of δJ relative to controls (<1 ‰) in near-surface soils in the first 2 years after disturbance; (b) depletion (1‰ or no change) during years 3–7; and (c) a second period of enrichment (1–2‰) in years 8–10. Results were consistent with isotopic patterns associated with the gradual death and decomposition of rhizosphere organisms, fine roots, conifer needles and woody roots and debris over the course of a decade after mortality. Finally, δJ was progressively more 13C-depleted deeper in the soil than near the surface, while the bulk soil followed the well-established pattern of 13C-enrichment at depth. Overall, differences in δJ between mortality classes (<1‰) and soil depths (<3‰) were smaller than variability within a class or depth over a season (up to 6‰).

Original languageEnglish (US)
Pages (from-to)1513-1523
Number of pages11
JournalPlant Cell and Environment
Volume39
Issue number7
DOIs
StatePublished - Jul 1 2016

Keywords

  • Abies lasiocarpa
  • Dendroctonus ponderosae
  • Picea engelmannii
  • Pinus contorta
  • carbon cycle
  • chronosequence
  • decomposition

ASJC Scopus subject areas

  • Physiology
  • Plant Science

Fingerprint Dive into the research topics of 'Carbon isotopic composition of forest soil respiration in the decade following bark beetle and stem girdling disturbances in the Rocky Mountains'. Together they form a unique fingerprint.

Cite this