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US Fish & Wildlife Service FieldNotes

FIRE MANAGEMENT: Fire Provides a Powerful Lesson in McGrath, Alaska

Region 7, October 23, 2013
Fire Management Officer Kristi Bulock (left) and Fire Ecologist Lisa Saperstein gather fuel samples.
Fire Management Officer Kristi Bulock (left) and Fire Ecologist Lisa Saperstein gather fuel samples. - Photo Credit: n/a
The Cranberry Ridge Fire near McGrath, Alaska.
The Cranberry Ridge Fire near McGrath, Alaska. - Photo Credit: n/a

The start of the Cranberry Ridge Fire near the town of McGrath in late May might have come as a surprise to some who live in the Interior Alaska village. But it wasn’t a surprise to the Fire Management Officer, volunteers with the Innoko National Wildlife Refuge and firefighters from the State of Alaska. The group had just wrapped up a day of training in fuel moisture sampling when they heard the season’s first clap of thunder. Soon after, a column of smoke appeared on the horizon.

Spring had been unusually late in coming. The snow finally melted when temperatures soared into the 80s for five days. Cooler, more seasonable temperatures soon returned, but those few days of warm temperatures were enough to remove significant moisture from vegetation making it easier to ignite, said Alaska Southwest Area Fire Management Officer Kristi Bulock. Though the weather did not suggest the fire danger was high, the fuel moisture measurements proved otherwise.

 

“The first two inches of fuel were ready, although everything below that was pretty wet or frozen,” Bulock said. In addition, the black spruce typically found in the Interior sees a steep drop in moisture content in the early spring – called the “spring dip” – as most of the moisture in the trees is pushed out to support new growth. As a result, a thick stand of black spruce five miles from town ignited quickly when lightning struck.

“The spruce was extremely volatile without much heat,” Bulock said.

Regional Fire Ecologist Lisa Saperstein had arrived the day before to train volunteers and staff of the two agencies to sample the moisture content in fuels. In fire parlance, fuels are any vegetation that can ignite and burn. By determining the amount of moisture in fuels, fire managers are able to determine the likelihood of ignition and how a fire might behave once ignited.

For many years fire managers in Alaska have relied on data collected from weather stations around the state and on formulas established in the Canadian Forest Fire Danger Rating System to determine fire danger. A statewide interagency effort is now under way to learn more about how that system correlates to the condition of the fuels in the field and how fuel moisture changes throughout the season as plants mature. Teaching those who live and work in McGrath to sample fuel moisture throughout the fire season will support this data-gathering effort.

After gathering and drying various types of vegetation and determining the amount of moisture in them, Saperstein and her trainees were able to see that the likelihood of ignition was moderate to high. The Cranberry Ridge Fire confirmed that the data gathered was accurate. Fortunately, firefighters from the Alaska Division of Forestry and the local volunteer fire department were able to respond quickly. The fire was contained at 15 acres and declared out two days later.

“The fire provided a powerful lesson at the end of class that served to drive home the importance of directly measuring live fuel moisture,” Bulock said.

Contact Info: Maureen Clark, (907) 786-3469, Maureen_Clark@fws.gov