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Fire Management

Forest Fire Ecology

A burning stumpEagle Creek Fire burned through a “wet” West Cascades forest that dominates the western Columbia River Gorge. Dominated by lush conifers, such as hemlock and firs, the forest floor is shady, cool, and moist throughout most of the year. Therefore, large wildfires tend to be infrequent in these types of forests. Historic records suggest that wildfires occured every 100 – 400 years in the West Cascades prior to modern human fire starts. When fires do occur in these forests, they tend to be intense megafires. This historic "fire interval" provides clues for understanding how plant and animal species are affected by, and naturally adapted to, wildfires. As it turns out, much of the Eagle Creek Fire perimeter had not seen a large fire for almost 100 years. There are some exceptions to this in certain areas, for example both Multnomah Falls and Angel's Rest experienced wildfires in the 1990s. 

Eagle Creek Fire, like most wildfires, burned unevenly. Instead of a leaving behind a completely scorched dead zone, they leave a patchwork of brown  and blackened areas with some green oases known as a burn “mosaic.” In this mix, severely burned areas have large groves of standing dead trees that will start to fall down in the years that follow. Moderately burned will have a mixed canopy, where some trees survive while others eventually succomb to their damage. Finally, lightly burned and unburned areas will have an intact, healthy tree canopy but the ground vegetation is burned away, opening up bare soil that is ready for new growth. Here, a "seed bank" of many decades worth of seeds will be ready to spring to life, bringing rapid new growth. This complex mix of forest stands creates more diverse conditions for plant species, and more types of habitat for animal species, even boosting the forest's biodiversity in the years that follow the fire. 

To illustrate differences in fire intensity, consider how Eagle Creek Fire burned. It started on Eagle Creek Trail and spread east for two days before winds carried it rapidly westward (pdf), jumping from ridge to ridge, on the night of September 4. Due to prevailing evening downslope winds, it then moved downhill throughout the night. If you look at the Soil Burn Severity map (pdf), you can the intensely burned areas shown in red high up on the ridges. Next time you drive the waterfall corridor section of the Historic Columbia River Highway, look at the black scars on the trees. These burn scars tend to be taller and more pronounced on the uphill side, indicating the fire's prevailing direction at the time. Notice also the burn map (pdf) shows a large zone of high intensity in the center of the fire, due to the fact that Eagle Creek Fire burned hottest and blazed the longest in that central zone. 

Forest Regeneration After Eagle Creek Fire

Screenshot of fire ecology flier showing first returnersFire is a natural phenomenon, even in the wet West Cascades forests, so the forest ecosystem has a natural process for regenerating. Most of the fire perimeter was located within the Mark O. Hatfield Wilderness area, so USFS policy is to “Allow reforestation only if a loss of the wilderness resource, due to human influence, has occurred and there is no reasonable expectation of natural reforestation” (Forest Service Manual 2323.54 (doc). Due to this, the Forest Service is not replanting large swathes of the burned area.

The Forest Service has teamed up with the Friends of the Columbia Gorge on an early detection and rapid response effort to prevent invasive species from becoming established. Friends of the Columbia Gorge regularly holds work parties to remove invasive species, and in some cases, plant native species. Interesting in helping? Visit our Ongoing Work page to learn about how to get involved.

Vegetation types within the fire perimeter include 37,418 acres of “Western Hemlock Zone,” 9,706 acres of “Pacific Fir Zone,” 880 acres of “Grand Fir Zone,” 500 acres of “Douglas Fir Zone," 174 acres of "Steppe," and 58 acres of “Mountain Hemlock Zone.” The remaining 51 acres of the fire took place in a mix of other vegetation types.

What to Watch for Next

In the coming years, visitors will be able to discover and chronicle the regeneration process on the scenic slopes of the Columbia Gorge. Use these Fire Ecology Story Cards (pdf) to get a sense of what to look for in the forest.

Research Projects

We are currently working with a number of scientific research partners on proposals to study the natural regeneration process in the Gorge. As these projects take shape, we will post more information here.

Fighting Future Fire Risks with Fire

Throughout the Gorge, the Forest Service uses management tools such as forest thinning and prescribed burns to mimic a natural fire interval. This is beneficial for recreating the area's natural history, supporting plant and animal biodiversity, and decreasing risks of catastrophic future fires by reducing “fuel loads.”

Note that the west Gorge is strikingly different from the “east end” of the Gorge, which is dominated by drier forests and grasslands. These drier ecosystems burn more frequently, but at a lower intensity. Most of the Gorge's fire management program tends to focus on managing fuels on the east end of the Gorge, where the risks of fire are greatest.

back to Eagle Creek Fire Response landing page.





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