Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Preprints
https://doi.org/10.5194/bg-2020-177
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-2020-177
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  03 Jul 2020

03 Jul 2020

Review status
This preprint is currently under review for the journal BG.

Hysteretic temperature sensitivity of wetland CH4 fluxes explained by substrate availability and microbial activity

Kuang-Yu Chang1, William J. Riley1, Patrick M. Crill2, Robert F. Grant3, and Scott R. Saleska4 Kuang-Yu Chang et al.
  • 1Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
  • 2Department of Geological Sciences and Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
  • 3Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
  • 4Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, USA

Abstract. Methane (CH4) emissions from wetlands are likely increasing and important in global climate change assessments. However, contemporary terrestrial biogeochemical model predictions of CH4 emissions are very uncertain, at least in part due to prescribed temperature sensitivity of CH4 production and emission. While statistically consistent apparent CH4 emission temperature dependencies have been inferred from meta-analyses across microbial to ecosystem scales, year-round ecosystem-scale observations have contradicted that finding. Using flux observations and mechanistic modeling in two heavily studied high-latitude research sites (Stordalen, Sweden, and Utqiaġvik, Alaska, USA), we show here that substrate-mediated hysteretic microbial and abiotic interactions lead to intra-seasonally varying temperature sensitivity of CH4 production and emission. We find that seasonally varying substrate availability drives lower and higher modeled methanogen biomass and activity, and thereby CH4 production, during the earlier and later periods of the thawed season, respectively. Our findings demonstrate the uncertainty of inferring CH4 emission or production from temperature alone, and highlight the need to represent microbial and abiotic interactions in wetland biogeochemical models.

Kuang-Yu Chang et al.

Interactive discussion

Status: open (until 14 Aug 2020)
Status: open (until 14 Aug 2020)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Kuang-Yu Chang et al.

Kuang-Yu Chang et al.

Viewed

Total article views: 184 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
135 45 4 184 8 4 5
  • HTML: 135
  • PDF: 45
  • XML: 4
  • Total: 184
  • Supplement: 8
  • BibTeX: 4
  • EndNote: 5
Views and downloads (calculated since 03 Jul 2020)
Cumulative views and downloads (calculated since 03 Jul 2020)

Viewed (geographical distribution)

Total article views: 137 (including HTML, PDF, and XML) Thereof 137 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 05 Aug 2020
Publications Copernicus
Download
Short summary
Methane (CH4) is a strong greenhouse gas that can accelerate climate change and offset mitigation efforts. A key assumption embedded in many large-scale climate models is that ecosystem CH4 emissions can be estimated by fixed temperature relations. Here, we demonstrate that CH4 emissions cannot be parameterized by emergent temperature response alone due to variability driven by microbial and abiotic interactions. We also provide mechanistic understanding for observed CH4 emission hysteresis.
Methane (CH4) is a strong greenhouse gas that can accelerate climate change and offset...
Citation