Response of soil respiration and its components to experimental warming and water addition in a temperate Sitka spruce forest ecosystem

Junliang Zou, Brian Tobin, Yiqi Luo, Bruce Osborne

Research output: Contribution to journalArticlepeer-review

28 Scopus citations

Abstract

Future climate change is expected to alter the terrestrial carbon cycle through its impact on soil respiration. In this study, we determined the responses of soil respiration and its components to experimental warming with or without water addition. A replicated in situ heating (∼2 °C above ambient soil temperatures) and water addition (170 mm in total each year) experiment was carried out for the first time in a temperate plantation forest of Sitka spruce over the period 2014–2016. Rh was measured inside deep collars (35 cm deep) that excluded root growth, while Rs was measured using the static chamber approach and near-surface collars (5 cm deep) and Ra calculated by subtracting Rh from total soil respiration (Rs). Experimental warming significantly increased Rs, Rh and Rh/Rs, but had no effect on Ra. In contrast, none of the respiration components were affected by water addition. Warming increased annual Rh by 62% but had no effect on Ra. Overall, warming did not significantly increase annual Rs. Warming showed a stronger impact on Rs in the non-growing season but had a smaller impact in the growing season. Warming increased Ra in the non-growing season but decreased it in the growing season. The effects of warming on Rh were similar for the two periods. Our results highlight the differential response of Ra and Rh to warming, which was mediated by water addition or season. For this and other similar forest sites that don't experience water limitation, global warming may have a positive feedback on atmospheric CO2 concentrations through enhanced soil respiration.

Original languageEnglish (US)
Pages (from-to)204-215
Number of pages12
JournalAgricultural and Forest Meteorology
Volume260-261
DOIs
StatePublished - Oct 15 2018

Keywords

  • Autotrophic respiration
  • Climate change
  • Heterotrophic respiration
  • Sitka spruce
  • Temperature sensitivity

ASJC Scopus subject areas

  • Forestry
  • Global and Planetary Change
  • Agronomy and Crop Science
  • Atmospheric Science

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