Linkages Among Climate, Fire, and Thermoerosion in Alaskan Tundra Over the Past Three Millennia

M. L. Chipman, F. S. Hu

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Amplified Arctic warming may facilitate novel tundra disturbance regimes, as suggested by recent increases in the rate and extent of thermoerosion and fires in some tundra areas. Thermoerosion and wildfire can exacerbate warming by releasing large permafrost carbon stocks, and interactions between disturbance regimes can lead to complex ecosystem feedbacks. We conducted geochemical and charcoal analyses of lake sediments from an Alaskan lake to identify thermoerosion and fire events over the past 3,000 years. Thermoerosion was inferred from lake sediments in the context of modern soil data from retrogressive thaw slumps (RTS). Magnetic susceptibility (MS), Ca:K, and Ca:Sr increased with depth in modern RTS soils and were higher on recently exposed than older slump surfaces. Peaks in bulk density, % CaCO3, Ca:K, Ca:Sr, and MS values in the sediments suggest at least 18 thermoerosion events in the Loon Lake watershed over the past 3,000 years. Charcoal analysis identifies 22 fires over the same period at this site. Temporal variability in these records suggests climate-driven responses of both thermoerosion and fire disturbance regimes, with fewer RTS episodes and fire events during the Little Ice Age than the Medieval Climate Anomaly. Moreover, RTS activity lagged behind catchment fires by 20–30 years (>90% confidence interval), implying that fires facilitated thermoerosion on decadal time scales, possibly because of prolonged active-layer deepening following fire and postfire proliferation of insulative shrub cover. These results highlight the potential for complex interactions between climate, vegetation, and tundra disturbance in response to ongoing warming.

Original languageEnglish (US)
Pages (from-to)3362-3377
Number of pages16
JournalJournal of Geophysical Research: Biogeosciences
Issue number12
StatePublished - Dec 2017
Externally publishedYes


  • Noatak National Preserve
  • paleoecology
  • retrogressive thaw slump
  • thermoerosion
  • tundra disturbance
  • wildfire

ASJC Scopus subject areas

  • Soil Science
  • Forestry
  • Water Science and Technology
  • Palaeontology
  • Atmospheric Science
  • Aquatic Science
  • Ecology


Dive into the research topics of 'Linkages Among Climate, Fire, and Thermoerosion in Alaskan Tundra Over the Past Three Millennia'. Together they form a unique fingerprint.

Cite this