Massive peatland carbon banks vulnerable to rising temperatures.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32398638.
- Also identified by DOI 10.1038/s41467-020-16311-8 and PMC identifier 7217827.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Peatlands contain one-third of the world's soil carbon (C). If destabilized, decomposition of this vast C bank could accelerate climate warming; however, the likelihood of this outcome remains unknown. Here, we examine peatland C stability through five years of whole-ecosystem warming and two years of elevated atmospheric carbon dioxide concentrations (eCO<sub>2</sub>). Warming exponentially increased methane (CH<sub>4</sub>) emissions and enhanced CH<sub>4</sub> production rates throughout the entire soil profile; although surface CH<sub>4</sub> production rates remain much greater than those at depth. Additionally, older deeper C sources played a larger role in decomposition following prolonged warming. Most troubling, decreases in CO<sub>2</sub>:CH<sub>4</sub> ratios in gas production, porewater concentrations, and emissions, indicate that the peatland is becoming more methanogenic with warming. We observed limited evidence of eCO<sub>2</sub> effects. Our results suggest that ecosystem responses are largely driven by surface peat, but that the vast C bank at depth in peatlands is responsive to prolonged warming.