This 2-page research brief summarizes several years of field studies-citing recently published articles-by USGS soil scientists Jennifer Harden and Kristen Manies. Their studies shed new light on the impact of fires on permafrost in Alaska boreal forest, and interactions of fire effects and freezing effects on the forest floor. The insulating moss/duff layer plays a critical role in protecting permafrost and conditions suitable for the rapid regrowth of permafrost are keys to determining whether boreal forest will retain its ability to store large amounts of biomass carbon.