Mt. Hood National Forest recovers from 36 Pit Fire
Along the highway through the Mt. Hood National Forest, islands of burnt trees stand out in an otherwise sea of green.
These trees stand as a reminder of the 36 Pit Fire, an incident that began in September 2014 as a result of a spark from target shooting at a rock pit near milepost 33 and Highway 224 in the forest.
The 5,521 acre fire bunt near the Big Eddy, Lazy Bend and Memaloose areas, among others.
Then-governor John Kitzhaber declared the incident a conflagration, which allowed state resources to help battle the blaze. More than 580 people, 16 crews, two helicopters and 28 engines from multiple agencies worked to put out the flames.
Though 97 percent of the fire was extinguished within two weeks, other parts of the fire continued to burn for several more weeks.
Three years after the fire, officials say much of the affected forestland is on the road to recovery.
"A lot of the landscape is resilient," said Todd Reinwald, Forest Watershed & Soils Program Manager for the Mt. Hood National Forest. He served as the Burned Area Emergency Response (BAER) coordinator for the fire and has tracked the landscape's response to the fire in the years since the incident.
There were several attributes in favor of the forest's recovery from the 36 Pit Fire, which was moderate in size compared to other fires the forest has seen in the last half century. Although the 36 Pit Fire burned at a high intensity, which refers to the behavior of the flames above ground, the soil burn severity was relatively low in many places. Because the fire was mainly driven by wind, it did not burn as hot as it could have near the ground. Reinwald noted that 75 percent of the area affected by the fire had a soil burn severity between low to moderate, which has helped during the recovery process.
"This means the fine roots under the soil surface, seeds and microorganisms survived the fire," Reinwald said, also noting that the region's rainy characteristics were also beneficial. "Rainfall is in our favor. It helps the seed bank and roots come back."
He added that many of the plants located below tall trees had grown back by the following spring.
Though much of the area involved in the fire had a low soil burn severity, not all of the land was affected in the same way.
"(Fire) burns like a mosaic," Reinwald said. "Some areas will come back faster, and it was hotter in other areas."
Several characteristics of the affected area caused the fire to have a more significant impact on sections of the land. For example, some areas were more heavily affected than others because of their steep, canyon-like terrain.
"There was a very steep burn area, and that makes it hotter," Reinwald explained. "With hills, fire preheats. It starts out flat and burns up. Heat rises, so everything in front dries out beforehand."
Additionally, Memaloose Road remains closed because of how the nearby terrain was affected.
"It's slower to recover because it's really steep and rocky," Reinwald said. "It's a different soil type for plants."
Additionally, the area continues to experience frequent erosion and landslides as part of the fire's aftermath. Both elements are particular concerns after fires because the reduced forest canopy results in more water reaching the ground, and root strength is often reduced.
In the years since the 36 Pit Fire, Reinwald estimates that Memaloose Road has had to be cleared because of landslides 12 times. He said the road will remain closed for at least another year.
"It's very rocky and steep, and gravity wins out," he said, discussing the terrain.
Another concern throughout the area affected by the fire is falling trees. Often, the trees that died in fires are difficult to cut down safely because their burns cause them to fall apart when they are cut.
"Trees will be falling for decades," Reinwald said. "As dead trees age, with weather and decay, they lose their strength and start fall-
ing. Some have come down already, but it's a continuing concern."
In terms of trees growing back, he estimated it will take 20 years for smaller trees to reach their mature size, and between 100 to 150 years for the old-growth forest to fully return.
Though the 36 Pit Fire was difficult for the landscape in many ways, it also resulted in several positive changes for wildlife in the forest.
For example, because of the fire, there are new plants, such as willow, growing in the forest that had not previously been there. This plant life serves as new food for animals like elk and deer.
Some animals are also drawn to the more open characteristics of the post-fire landscape.
"Not all animals like really closed, old growth areas," Reinwald said. "Some like younger, more open spaces. For the next several decades, deer and elk will thrive in the burned-over areas."
Reinwald noted that in the coming years, the area affected by the 36 Pit Fire will continued to be monitored season-to-season.
"We'll see how things are coming back," he said.