Uncharted Flames: Clues to an Unmapped Wildfire in Wrangell-St. Elias

Beneath the layer of decaying needles and moss on the forest floor, a fire ecologist digging a soil pit in Wrangell-St. Elias National Park and Preserve found a band of charcoal lying directly on the mineral soil — a sign, perhaps, of an intense fire. Nearby stood an old charred stump, grown over with lichen. Fire history maps showed that one of the two areas they were studying had burned in 1948. But the evidence turned up at both — including one where no fire was recorded.

Olivia Lawrence, an Eastern Area Fire Management fire effects biotechnician, collects data at a soil pit and finds evidence of past fire. Credit: Mariana Perez, National Park Service.

Why they were there

With Bipartisan Infrastructure Law funding, fire ecology teams from the Park Service's Alaska Eastern and Western Area Fire Management installed 13 monitoring plots around two Native allotments along the McCarthy Road, inside the park's legislated boundary. Because of the values at risk, these areas are designated for full suppression of any wildfire, and fuel reduction treatments were planned for 2024. The plots give a baseline of conditions before treatment, so managers can later judge whether the treatments met their goals and what the area needs next. The area has burned before, but how often fires return there is not well understood.

Left: a charcoal layer under the duff, directly above mineral soil, possibly from a high-intensity fire. Right: an old charred stump covered in lichen. Credit: Olivia Lawrence, National Park Service.

Reading the trees

When the team returns, they will take tree cores and cross-section "cookies" to find the trees' ages. Fires in interior Alaska's forests usually replace the whole stand, so the age of the oldest trees gives a minimum time since the last fire — and, over many plots, a better sense of how often fire returns to the park.

The crew climbs over trees downed in an area hit by a spruce bark beetle outbreak in the late 1990s. Credit: Olivia Lawrence, National Park Service.

The Eastern and Western Area fire ecology team at their last monitoring plot, when the mosquitoes eased enough to unzip their bug hoods. Credit: Mariana Perez, National Park Service.

Sources

Based on "Uncharted Flames: NPS Alaska Fire Ecology Team Discovers Evidence of an Unmapped Wildfire in Wrangell-St. Elias National Park and Preserve," National Park Service, a work of the United States government in the public domain. The work was funded by the Bipartisan Infrastructure Law, signed November 15, 2021.