Evidence for nonuniform permafrost degradation after fire in boreal landscapes

Journal of Geophysical Research F: Earth Surface
By: , and 

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Abstract

Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability and resilience of different landscapes to permafrost degradation are needed. We present a combination of multiscale remote sensing, geophysical, and field observations that reveal details of both near-surface (<1 m) and deeper (>1 m) impacts of fire on permafrost. Along 11 transects that span burned-unburned boundaries in different landscape settings within interior Alaska, subsurface electrical resistivity and nuclear magnetic resonance data indicate locations where permafrost appears to be resilient to disturbance from fire, areas where warm permafrost conditions exist that may be most vulnerable to future change, and also areas where permafrost has thawed. High-resolution geophysical data corroborate remote sensing interpretations of near-surface permafrost and also add new high-fidelity details of spatial heterogeneity that extend from the shallow subsurface to depths of about 10 m. Results show that postfire impacts on permafrost can be variable and depend on multiple factors such as fire severity, soil texture, soil moisture, and time since fire.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Evidence for nonuniform permafrost degradation after fire in boreal landscapes
Series title Journal of Geophysical Research F: Earth Surface
DOI 10.1002/2015JF003781
Volume 121
Issue 2
Year Published 2016
Language English
Publisher AGU Publications
Contributing office(s) Earth Resources Observation and Science (EROS) Center, Crustal Geophysics and Geochemistry Science Center
Description 16 p.
First page 320
Last page 335
Country United States
State Alaska