Cutting, burning and measuring: how Alaska’s parks reduced fire risk around headquarters

Large wildfires are common and natural in the boreal forests of many National Park units in Alaska. Left unprepared for, they can harm communities, infrastructure and other values of concern. To lower that risk around park headquarters and visitor centers, Denali and Wrangell-St. Elias National Park & Preserves completed fuels treatments on 6 acres, pile burns on 33 acres and monitoring on 30 acres in 2021.

Three kinds of work

• Fuels treatment: thinning and limbing flammable trees and shrubs reduces the chance of crown fire and gives firefighters better access to protect structures.
• Pile burning: woody debris from thinning that has no other use, such as stoking a woodstove at a remote cabin, is burned in piles. Winter or spring is the time to burn piles in Alaska.
• Monitoring: this checks whether the treatments worked. Did they reduce the fire risk? When must they be redone? Are there invasive plants or changes in the understory afterward?

Eastern Area fire staff burned woody debris in April that came from the fuels treatment site at the Wrangell-St. Elias headquarters and visitor center thinning project. NPS photo.

Crews and sites

The NPS fire programs in Alaska (Region 11) treat fuels around structures so that naturally occurring wildfire can be managed more often and its effects on structures reduced. Area programs hire fuels crews of 4-6 people, who run chain saws, burn piles, monitor fuels, work with helicopters and respond to fires. In 2021 the Western Area crew thinned around the Denali Administrative Camp and other sites. Both crews thinned at 30 other sites that summer and burned debris piles elsewhere. In early April the Eastern Area crew burned a large pile at Wrangell-St. Elias that came from areas thinned at the headquarters in 2020.

Measuring with laser scans

In 2021 the park fire ecologists and fuels crew collected tree and fuels data at 46 plots in Denali and 19 in Wrangell-St. Elias where past treatments had been made and new ones were under way. In Denali the ecologists also used a new technology, 3D terrestrial lidar scanning, to assess changes before and after treatment in variables such as tree density, canopy height and cover. The field plot data will calibrate the scanner’s measurements.

Terrestrial lidar scans of a monitoring plot after thinning at the Denali Admin Camp. The scanner takes a 360-degree photo of the site and a point cloud of data that can be used to determine tree height, cover and canopy height.

Funding from the federal Active Forest Management program paid for the Alaska NPS Fire Management Program’s treatments and for monitoring how effective they are.

Sources

• National Park Service, “Reducing fire risk – treating, burning, and monitoring fuels treatments in Denali and Wrangell-St. Elias headquarters,” https://www.nps.gov/articles/000/reducing-fire-risk-treating-burning-and-monitoring-fuels-treatments-in-denali-and-wrangell-st-elias-headquarters.htm; rewritten in hubnx’s own words.