Nature Communications (Nov 2023)

Climate warming and elevated CO2 alter peatland soil carbon sources and stability

  • Nicholas O. E. Ofiti,
  • Michael W. I. Schmidt,
  • Samuel Abiven,
  • Paul J. Hanson,
  • Colleen M. Iversen,
  • Rachel M. Wilson,
  • Joel E. Kostka,
  • Guido L. B. Wiesenberg,
  • Avni Malhotra

DOI
https://doi.org/10.1038/s41467-023-43410-z
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 10

Abstract

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Abstract Peatlands are an important carbon (C) reservoir storing one-third of global soil organic carbon (SOC), but little is known about the fate of these C stocks under climate change. Here, we examine the impact of warming and elevated atmospheric CO2 concentration (eCO2) on the molecular composition of SOC to infer SOC sources (microbe-, plant- and fire-derived) and stability in a boreal peatland. We show that while warming alone decreased plant- and microbe-derived SOC due to enhanced decomposition, warming combined with eCO2 increased plant-derived SOC compounds. We further observed increasing root-derived inputs (suberin) and declining leaf/needle-derived inputs (cutin) into SOC under warming and eCO2. The decline in SOC compounds with warming and gains from new root-derived C under eCO2, suggest that warming and eCO2 may shift peatland C budget towards pools with faster turnover. Together, our results indicate that climate change may increase inputs and enhance decomposition of SOC potentially destabilising C storage in peatlands.