Reducing fire risk – treating, burning, and monitoring fuels treatments in Denali and Wrangell-St. Elias headquarters

It takes a team! NPS Alaska Western Area fuels crew thinned trees and removed flammable vegetation at Denali front country and back country structures in 2021. NPS area programs in Alaska hire fuels crews that run chain saws, burn piles, monitor fuels, work with helicopters, and respond to fires.

Sarah Hayes, NPS

Large wildfires are common and natural in boreal forests of many National Park units in Alaska. If not prepared, wildfires can often have negative impacts to communities, infrastructure, and values of concern. To reduce the potential negative impacts due to wildfire around park headquarters and visitor centers, Denali and Wrangell-St. Elias National Park & Preserves completed fuels treatments (6 acres), pile burns (33 acres), and monitoring (30 acres) in 2021.

Fuels management, comprised of thinning and limbing of flammable trees and shrubs, reduces the potential for crown fire and provides better access for fire fighters to protect structures. Burn piles are used to dispose of the woody debris from thinning that is not used for other purposes (i.e., stoking the woodstove at a remote cabin). Monitoring assesses the effectiveness of the fuels treatments: Did we reduce the fire risks? When does it need to be treated again? Are there invasive plants or changes in the understory after treatment?

The NPS fire programs in Alaska (Region 11) implement fuels treatments around structures to increase opportunities to manage vegetation through naturally occurring wildfire and to reduce potential wildfire impacts to structures. Fuels crews of 4-6 people are hired by the NPS Alaska Area programs. In 2021, the Western Area fuels crew thinned around the Denali Administrative Camp and other sites.

Winter or spring is the time to burn piles in Alaska.  NPS Alaska Eastern Area fire staff burned woody debris in April that was removed from a fuels treatment site at Wrangell-St. Elias National Park Headquarters and Visitor Center thinning project.

Brian Mork, NPS

Trees were cut or limbed and woody debris was removed to be burned off-site in a burn pile. The Eastern Area fuels crew burned a large woody debris pile at Wrangell-St Elias in early April that came from areas thinned at the Wrangell-St. Elias headquarters in 2020. Both fuels crews thinned at 30 other sites during the summer of 2021 and burned debris piles at other locations.

Monitoring fuels treatments provides fire management with important information on the effectiveness and treatment schedule. In 2021, the NPS fire ecologists and fuels crew collected tree and fuels data at 46 plots in Denali and 19 plots in Wrangell St. Elias where past treatments have occurred and new treatments are being implemented. The fire ecology program utilized new technology to monitor; 3D Terrestrial Lidar Scans (TLS) were taken at the plots in Denali to assess changes before and after fuels treatments for variables such as tree density, canopy heights and cover. The field plot data will be used to calibrate the scanner data with field measurements.

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

Fire bio technician setting up the Terrestrial Lidar Scanner at fuels treatment monitoring site in Denali. The dense spruce has not been thinned at this control site.

Jennifer Barnes, NPS

Funding from the federal Active Forest Management­­ provided the AK NPS Fire Management Program treatment funds and fuels treatment effectiveness monitoring.