Wildfire risk assessment informs placement and design of treatments.
Photo by Umatilla Veteran Crew, U.S. Forest Service
Fire season is in full swing. In the Blue Mountains, the weather is hot, the fuels are dry, and fire danger is extreme. Last summer’s fire season set the record as the largest in U.S. history, totaling more than 10 million acres reported as burned. The Blue Mountains National Forests of Oregon and Washington reported more than 282,000 acres burned. Throughout the area, unusually large and severe wildfires have become more common due to overcrowded forest conditions, extended late season drought, and the loss of fire-tolerant tree species (find out more in Taking Action to Restore the Blue Mountains.)
While wildfire is a natural part of forest ecosystems in the Pacific Northwest, recent fires across the region make clear that it can also pose a threat to human lives, private property, and other highly valued resources and assets. For the Forest Resiliency Project, highly valued resources and assets have been identified, which include areas such as old forest structure, riparian habitats for federally listed fish, and municipal watersheds. The project aims to strategically identify opportunities to place fuels treatments across the landscape in order to protect these resources.
Municipal watersheds are one example of a highly valued resource and asset that forest managers are interested in protecting. The five municipal watersheds on the Umatilla and Wallowa-Whitman National Forests (none exist on the Ochoco) are primary or secondary water sources for several communities in the Blue Mountains. For example, the Mill Creek Watershed is located on the Umatilla National Forest and provides 80-90% of the drinking water for the city of Walla Walla. Each of the municipal watersheds on these Forests are partially made up of moist forest types, which usually occur at mid elevations and are often the most productive sites due to the amount of available moisture. Moist forest types consist of mixed tree species, such as grand-fir, Douglas-fir, ponderosa pine, western larch, lodgepole pine and Engelmann spruce. In many of these areas, dense conifer stands and heavy accumulations of dead and down material have created hazardous fuels conditions. In the event of a wildfire, these conditions are likely to produce a high intensity fire, and adversely impact the local communities’ water sources and make these areas unsafe for firefighters to engage in fire suppression efforts.
How do we mitigate that risk? That is what the Forest Resiliency Project is all about—designing treatments to transition our public lands to more resilient conditions that can maintain critical ecosystem function and processes in the face of disturbances, like wildfire. The Blue Mountains Restoration Strategy team is attempting to accomplish this by managing the project area within all three forests toward more resilient landscape forest patterns, concentrating on mitigating the risk from uncharacteristic wildfires.
Wildfire Risk Assessment
Being able to quantify the risks posed by wildfire can help forest managers prioritize and develop cost-effective mitigation strategies. To do so, fire and fuel managers need information on where fires are likely to occur, the intensity at which they might occur, and what impacts wildfires could have to highly valued resources and assets.
The planning team is conducting a Wildfire Risk Assessment to inform strategic wildfire management decision-making. Using this tool, forest managers will look at what is MOST at risk and WHERE these risks are on the landscape. The analysis helps managers better understand the effectiveness of fuels treatments based on the likelihood of wildfires occurring, the intensity at which they may occur, and the impacts that future wildfires pose to old growth forests, riparian areas, drinking watersheds, and communities.
This tool also shows the areas where wildfire could enhance or benefit highly valued resources and assets. In order to restore forest resilience, especially in the face of an uncertain future climate, fire needs to be recognized as an important management tool (see more about the benefits of fire in the April blog post The importance of fire). For example, some plants, such as quaking aspen, respond to fire by sending up new sprouts from the below-ground root system when the parent tree is damaged by fire. Fire also reduces the canopy cover in an area, giving quaking aspen more opportunity to grow.
By thoughtfully planning and implementing thinning and prescribed fire now, our national forests are facilitating the role of fire as a restoration tool – one that can be used in a safer, less expensive, and less damaging manner than is currently possible. Essentially, the wildfire risk assessment shows us the likely exposure and effect of wildfire on highly valued resources and assets and is used as a basis to evaluate the effectiveness of different treatment alternatives. One of the Forest Resiliency Project’s goals is to support safe and effective fire management- across all forest types. The team will use the results of the risk assessment to design and develop strategically placed fuel treatments, with the objectives of modifying fire behavior potential, improving firefighter and public safety, and protecting values at risk.
Wildfire has historically been a regular occurrence in northeast Oregon and southeast Washington. It is not a matter of if the next wildfire will occur, but a matter of when. And fire is really what the Forest Resiliency Project is all about—preparing our national forest landscapes so that we can better manage with fire instead of against fire.
This is the eighth of twelve issues of Features from the Blue Mountains Restoration Strategy brought to you by Sustainable Northwest and the U.S. Forest Service Blue Mountains Restoration Strategy Team. This monthly series highlights the environmental and economic challenges and opportunities present in the Blue Mountains region, and includes updates from the Blue Mountains Forest Resiliency Project.