The , adopted in 1994, helped quell mounting tensions between timber companies and environmentalists. It protected large swaths of old-growth forest in Washington, Oregon and California to preserve habitat for endangered species, including the and .

While the plan is largely considered a success, researchers and land managers have begun to question whether it adequately protects forests threatened by climate change. Wildfires of increasing strength and severity sweep through Northwest forests every year, both on the east side of the mountains where conditions are drier and in wet mossy western forests.

, researchers looked at more than 2,200 fires over several decades to evaluate how wildfire is impacting Northwest Forest Plan lands. They observed a steady uptick in area burned and severity of wildfire in both dry and moist protected forests during the study period.

Federal and state representatives have been in conversation about for several years now. A new iteration of the Northwest Forest Plan could lean on more active management, including intentional burning and Indigenous cultural burning, which involves strategically introducing fire to maintain ecosystem health.

91探花News asked the study鈥檚 lead author, , a 91探花senior research scientist of environmental and forest sciences, what the new research means for the plan.

Why did you do this study?

Gina Cova: For several years now, people have talked about revisiting the Northwest Forest Plan to incorporate amendments that account for the effects of recent wildfires and climate change. Some of these conversations were inspired by executive orders emphasizing the importance of old-growth forest protections. Others followed new research documenting the effects of climate change across the region.

We鈥檝e seen more fire within the Northwest Forest Plan area, both in dry, fire-prone forests, but also in moist forests that we consider less likely to burn. Those events included a few really high-profile fires, such as the that burned close to 175,000 acres in western Oregon and raised questions about land management strategies in this era of climate change. We started to think about evaluating these past fires to inform plan amendments aimed at management strategies to sustain old forests across the region.

What were some of the key takeaways from the study?

GC: 聽A broad theme is that these are dynamic landscapes and they need to be managed as such. We looked at the environmental factors driving burn severity for 2,200 different wildfires and studied the forest patterns resulting from those events. The effects of wildfire in some areas were surprising. For example, we found that high severity fire affected around 60% of pine-oak woodlands in federally protected reserves throughout the eastern Cascades and Klamath regions. These forests are adapted to frequent, low intensity fires. We know that they need fire, but the severity of these fires reflects a long history of fire exclusion 鈥� or lack of fire 鈥� across the landscape.

What do you mean by a lack of fire? Aren鈥檛 we supposed to stop wildfires?

GC: Because enacting changes to management strategies has been difficult to do in practice, parts of the Northwest Forest Plan inadvertently reinforced the idea of preserving a static forest condition. This approach is analogous to drawing a boundary around a forest to prevent disturbance. It is rooted in conservation ideas from the early and mid-20th century, but we know that disturbances 鈥斅爀specially fire 鈥� are important for forests. So, you get this kind of fire paradox where many of these forests need fire, but the longer they go without it the more devastating it ultimately becomes.

These frequent-fire forests 鈥� like pine-oak woodlands and dry mixed conifer forests 鈥� can ultimately fare better in a warmer climate, so it is really alarming to see how much dry forest cover we are losing to fire under current management strategies.

What about other forests? How can one plan account for both dry and moist forests?

GC: It鈥檚 going to require a bit of creativity, combined with place-based, local approaches. The past three and a half decades have been relatively quiet in terms of fire activity in moist forests west of the Cascade Mountains. However, over the past 10 years, we observed an increase in area burned and area burned at high severity, indicating more loss of forest cover. This trend reflects some of these big fire years that have occurred in the last decade.

It can be harder to predict future wildfire activity in moist forests. When fires do occur, our study documented several occasions where high severity fires affected entire forest reserves. This creates gaps in this network of old forest habitat the plan was designed to create. If recent wildfires have compromised that original goal, how might future management strategies need to adapt? This could look like adjusting the boundaries of existing forest reserves, implementing protections for forests outside of reserves or building flexibility into pre-and post-fire management strategies to protect forests.

How can we keep the plan current when conditions are changing so quickly?

GC: When you manage land with a focus on a single issue, or a limited set of issues, you鈥檙e going to run into problems. The plan accounted for the effects of wildfire as it was in 1994, but did not anticipate how wildfire would shift with climate change. We don鈥檛 necessarily need to know exactly what the landscape will look like in the future, but we need policies and management strategies that will allow us to adapt to changing and novel conditions.

We have pretty strong evidence that the next century will be warmer and bring more fire. Can we create a plan that incorporates adaptive management to anticipate some of these changes instead of just responding to them as they occur.

Co-authors include , a 91探花research scientist and , a 91探花research associate professor, both of environmental and forest sciences; Harold Zald of the USDA Forest Service, and of the Washington Conservation Science Institute.

This research was partially funded by the USDA Forest Service.

For more information, contact Cova at cova@uw.edu.

There are 154 national forests in the United States, covering nearly 300,000 square miles of forests, woodlands, shrublands, wetlands, meadows and prairies. These lands are increasingly recognized as vital for supporting a broad diversity of plant and animal life; for water and nutrient cycling; and for the human communities that depend on forests and find cultural and spiritual significance within them. Forests could also be potential bulwarks against climate change. But, increasingly severe droughts and wildfires, invasive species, and large insect outbreaks 鈥� all intensified by climate change 鈥� are straining many national forests and surrounding lands.

A by a team of 40 experts outlines a new approach to forest stewardship that 鈥渂raids together鈥� Indigenous knowledge and Western science to conserve and restore more resilient forestlands. Published March 25, the report provides foundational material to inform future work on climate-smart adaptive management practices for land managers.

鈥淥ur forests are in grave danger in the face of climate change,鈥� said , an associate dean of forestry at Oregon State University. 鈥淏y braiding together Indigenous knowledge with Western science, we can view the problems with what is known as 鈥楾wo-Eyed Seeing,鈥� to develop a path forward that makes our forests more resilient to the threats they are facing. That is what this report is working to accomplish.鈥�

Eisenberg co-led the report team with , a fire ecologist in the School of Environmental and Forest Sciences at the 91探花.

鈥淐limate change is stressing these forests even as they are considered for their potential role in slowing rates of climate change,鈥� said Prichard. 鈥淲e want this report to provide not just guidance, but also hope 鈥� hope in the practical measures we can take now to promote resiliency and help forests thrive.鈥�

Initiated by interest from the Forest Service on Indigenous knowledge and Western science, the report stems from direction to protect old and mature forests outlined in , signed by President Joe Biden in April 2022. These types of forests, some hundreds of years old, are often dominated by larger trees, with fewer seedlings and saplings. Some management practices over the past century have made many of these forests vulnerable to drought, fire, insects and other stressors, all of which will likely increase with climate change.

The executive order included guidance on strengthening relationships with tribal governments and emphasized the importance of Indigenous knowledge, a theme highlighted repeatedly in the new report. This knowledge includes the time-tested practices of Indigenous stewardship that for millennia shaped forest structure and species composition. Following European colonization, these practices were sharply curtailed by genocide, displacement, and forced assimilation of Indigenous peoples. Western scientists increasingly recognize that Indigenous stewardship practices built and maintained forests that were more resilient and ecologically diverse than today.

Many Indigenous cultures, for example, used a practice called intentional burning 鈥� also known as cultural burning 鈥� which decreased forest density, promoted healthy understory growth, and hosted a broad diversity of plant and animal life. These practices over time yielded 鈥渕osaics鈥� of forests made up of diverse patches of trees varying in age, density, and overstory and understory composition. These 鈥渕osaic鈥� forests are less prone to the types of large, severe wildfires that have burned swathes of North American forests this century, according to Prichard.

Other members of the core leadership team for the report are , a senior research ecologist with the Forest Service鈥檚 Pacific Northwest Research Station, and , a professor and director of the Center for the Future of Forests and Society at OSU.

鈥淭wo powerful ideas we heard from our Indigenous colleagues in developing this are those of reciprocity and the seven generations principle. Collectively, the writing team agrees that we can frame a more sustainable land ethic with these ideas,” said Hessburg. 鈥淭hese perspectives guided our recommendations, which suggest taking from the land and giving back in equal measure, and proactively stewarding these lands with seven generations in mind.鈥�

come from tribal nations, universities, U.S. Forest Service research stations, consulting groups, Natural Resources Canada, Parks Canada, and Tall Timbers Research Station and Land Conservancy.

鈥淥ur report is deeper than changes in policy and management 鈥� it proposes a fundamental change in the worldview guiding our current practices,鈥� said Nelson. 鈥淥ur writing team鈥檚 cultural, geographic and disciplinary diversity allows for guidance on a shift in paradigms around how we approach forest stewardship in the face of climate change.鈥�

The report may also inform Forest Service work on the proposed national forest land plan intended to steward and conserve old-growth forest conditions.

鈥淲e are very interested in understanding how Indigenous knowledge can be used in combination with western science to improve our management of all forest conditions including old growth,鈥� said Forest Service Deputy Chief Chris French. 鈥淭his report is a big step in improving our understanding of how to do that.鈥�

The report is available for download , along with an interactive map highlighting more than 50 examples of forest adaptation strategies. It was funded by the U.S. Forest Service, the Resources Legacy Fund, the 444S Foundation, the Doris Duke Charitable Foundation, the Gordon and Betty Moore Foundation, and the Wilburforce Foundation.

For more information, contact Prichard at sprich@uw.edu, Hessburg at paul.hessburg@usda.gov, Eisenberg at Cristina.Eisenberg@oregonstate.edu, and the Forest Service press office at sm.fs.pressoffice@usda.gov.

In 2006, the Tripod Complex Fire burned more than 175,000 acres in north-central Washington. The fire, which was within the Okanogan-Wenatchee National Forest, was more than three times the size of Seattle. Yet while considered severe at the time, even larger wildfires in 2014, 2015 and 2021 have since dwarfed Tripod.

Past research shows that large and severe wildfires like these were much rarer in the western U.S. and Canada prior to the late 20th century.

鈥淔ire exclusion policies for much of the 20th century yielded many dense forests with largely uniform composition,鈥� said , a research scientist with the 91探花School of Environmental and Forest Sciences. 鈥淏y the turn of this century, we had mature and densely treed, multi-layered forests with high fuel content 鈥� and as a result, large, destructive wildfires can ignite and spread more easily. There鈥檚 simply more to burn across large landscapes.鈥�

Prichard, along with colleagues from the U.S. Forest Service鈥檚 Pacific Northwest Research Station 鈥� , Nicholas Povak and Brion Salter 鈥� and consulting fire ecologist Robert Gray, have created a modeling tool that will allow managers and policymakers to imagine and realize a different future: one where large, severe wildfires like Tripod are once again rare events, even under climate change.

The tool, known as REBURN, can simulate large forest landscapes and wildfire dynamics over decades or centuries under different wildfire management strategies. The model can simulate the consequences of extinguishing all wildfires regardless of size, which was done for much of the 20th century, or of allowing certain fires to return to uninhabited areas. REBURN can also simulate conditions where more benign forest landscape dynamics have fully recovered in an area.

In a pair of papers published and in the journal Fire Ecology, the team applied REBURN to the region in north-central Washington where the 2006 Tripod Complex Fire burned. Simulations showed that setting and allowing smaller wildfires to burn can yield more varied and resilient forests over time. Such forests are made up of forest condition 鈥減atches鈥� of different sizes and shapes, and all at different stages of recovery from their most recent fire. Patches that recently burned acted as 鈥渇ences鈥� to the flow of fire for at least the next 5 to 15 years, preventing wildfires from spreading widely. REBURN simulations showed that a forest landscape comprised of 35 to 50% 鈥渇ence鈥� areas had far fewer large-scale and damaging wildfires.

鈥淟andscapes had tipped to more 鈥榖enign鈥� burning conditions,鈥� said Hessburg.

REBURN simulations showed that, when fence areas were less abundant across a region, larger and more severe wildfires tended to dominate how the landscape developed over time.

鈥淭he model allows us to simulate what can happen when different management scenarios are applied before the fact, including how small or medium-sized fires in uninhabited areas can reshape forest vulnerability to fires,鈥� said Prichard. 鈥淲e found that having a more complex forest environment 鈥� in terms of tree age, composition, density, fuel content 鈥� makes it harder for large fires to spread and become severe.鈥�

鈥淲e also found that non-forest areas comprised of grasslands, shrublands, wet and dry meadows, and sparsely treed woodlands were key ingredients of wildfire-resilient forests,鈥� said Hessburg. 鈥淩EBURN showed us that our policy of extinguishing all wildfires created forests like those that exist today, with large, severe wildfires growing more prevalent. In addition to destroying homes and blanketing cities and towns with smoke, conflagrations like these displace wildlife, destroy habitats, and can burn large areas severely, sometimes making it difficult for forests to return.鈥�

Short intervals between forest reburns can be especially harmful for long-term recovery by destroying young trees that have not yet produced cones, they added.

From 1940 to 2005 in Washington鈥檚 North Cascades, fire crews extinguished more than 300 fires in their early stages in the Tripod area 鈥� most triggered by lightning strikes. By the 1980s and 1990s, forests in the region had become high-density tinderboxes, loaded with older, dying trees and lots of dead wood and other fuel on the ground.

Research has shown that before large-scale European colonization of the area, smaller wildfires shaped forests in north-central Washington and elsewhere in the Pacific Northwest. The Methow people and other tribes in the region actively set fires through cultural burning practices. Aerial photos show that, as recently as the 1930s, forests in north-central Washington had a 鈥減atchwork quilt鈥� structure that kept large wildfires from forming easily.

鈥淔orests with more complex structure 鈥� including densely and lightly treed areas like meadows and grasslands, shrublands, and spare woodlands 鈥� also create a wider variety of habitats for wildlife,鈥� Hessburg said. 鈥淩ecently burned areas can develop into wet or dry meadows that can host deer or moose. Other, younger tree-dense areas can host lynx and snowshoe hares.鈥�

REBURN can be adapted to other regions in the western U.S. and Canada. Prichard, Hessburg and their colleagues are currently adapting it to simulate forest development in the vast forests of southern British Columbia and northern California, including regions recently hit by wildfires and those culturally burned by Indigenous people.

But knowing when 鈥� or even whether 鈥� to allow a small fire to burn in an uninhabited region is no easy task, since fire managers must protect people, their homes and livelihoods. The team hopes ongoing research will help refine the model and the insight it can provide to modified forest management strategies.

鈥淭his is a new type of tool that couples forest and non-forest development models over time, fuel fall-down after fires, and a fire growth model,鈥� said Hessburg.

鈥淲e hope that it will help people who make major decisions about our forests understand the long-term consequences of different practices and policies when it comes to wildfires,鈥� said Prichard. 鈥淲e hope it will make these conversations easier to have by grounding our predictions in sound forest science.鈥�

The research was funded by the Joint Fire Science Program and the U.S. Forest Service Pacific Northwest Research Station.

For more information, contact Prichard at 509-341-4493 and sprich@uw.edu and Hessburg at 509-423-6738 and paul.hessburg@usda.gov.

All forest fire smoke is bad for people, but not all fires in forests are bad.

This is the conundrum faced by experts in forest management and public health: Climate change and decades of fire suppression that have increased fuels are contributing to larger and more intense wildfires and, in order to improve forest health and reduce these explosive fires, prescribed and managed fire is necessary.

These intentional fires 鈥� some deliberately set and others unintended but allowed to burn under control 鈥� will reduce the intensity of wildfire smoke in the long run, but they are still creating health-impacting smoke, often hitting populations least protected from exposure to smoke.

To find consensus on how to deal with the impacts of all fires on dry Western forests, the 91探花 and The Nature Conservancy led a series of conversations involving roughly 60 experts charged with keeping forests and people healthy. The led the organization of these discussions.

On May 2, more than two dozen of those participants that is part review of current scientific understanding of the issues and health impacts and part consensus report on how to deal with them.

鈥淚t started as a conversation between experts who think about fire from really different angles in order to find how we can address fire through an interdisciplinary lens,鈥� said lead author , a postdoctoral fellow in UW鈥檚 Department of Environmental & Occupational Health Sciences. 鈥淚t took a little bit to get to the fact that it was really smoke that brought us all together. We kind of had to set a baseline for what peoples鈥� starting points were 鈥� all smoke is bad smoke from a public health perspective, but we can’t do fire management without more fire.鈥�

That working group 鈥� comprised of scientists, practitioners and managers who specialize in areas of forest and fire ecology, fire safety, air quality, health care and public health 鈥� agreed on six statements and recommendations as part of its 鈥渋nterdisciplinary approach鈥� to the issues.

鈥淭he Nature Conservancy is dedicated to an evidence-based approach to forest and fire management practices that supports the health of both nature and people. These consensus statements aim to serve as guideposts for forest health and public health professionals to work together to promote healthy and resilient forests and communities,鈥� said , co-author and director of conservation science for The Nature Conservancy in Oregon.

The first consensus statement addresses the issue of the long-running effort to suppress all forest fires versus the historic practices of Indigenous peoples:

鈥淲e recognize the need to listen to and integrate a diversity of perspectives, in particular those embodied by Indigenous peoples who have successfully used fire as an ecological tool for thousands of years,鈥� the authors wrote.

鈥淚鈥檝e often heard from Tribal leaders how controlled burns were one of many tools they employed historically to steward healthy ecosystems,鈥� said , co-author and executive director of the Tribal Healthy Homes聽Network. 鈥淭his Tribal knowledge has been overlooked, perilously, during decades of European colonization, and federal land management practices. It is only in recent years, as forest ecosystems decline in health, that Western science has begun to recognize and learn from the innate sensibility and sustainability of traditional Tribal burning practices.鈥�

Here are the other five consensus statements:

• Prescribed fires in addition to managed fires for resource benefit are both necessary management techniques to keep forests resilient and to lessen the negative ecological and public health impacts of wildfires.
• Certain regions of the Western U.S. will experience more smoke days with heightened use of prescribed and managed fire; however, we expect the impacts of smoke exposure to be reduced over the long term in comparison with untreated land burned by wildfires. With these techniques, exposure in affected communities can be planned and lessened.
• No degree of smoke exposure is without risk. However, additional investment in advance preparation for affected populations can lower associated health risks. A smoke-resilient community is resilient to smoke from any type of fire.
• We must work to promote both equity in process (e.g., who has a say in decision-making) and equity in outcomes (e.g., who gets exposed to the smoke) within those communities and populations experiencing disproportionate impacts from smoke.
• We are missing opportunities for positive impact by working as separate disciplines. We recommend that further and intentional integration of forest/fire and health disciplines (including the practitioners, tools and resources) needs to occur to lessen the human health effects of smoke exposure due to prescribed and managed fires.

In their conclusion, the authors point out that when all stakeholders work together to 鈥渃ombat this climate and public health crisis,鈥� communities will be more able to meet these goals, both during and outside of wildfire season.

鈥淓xtra attention must be given to people who have more smoke exposure, are more likely to experience health problems from smoke, and who don鈥檛 have enough support to anticipate, adapt, respond or recover from smoke,鈥� added聽, senior author and associate professor of environmental and occupational health sciences in the 91探花School of Public Health. 鈥淭hese disproportionately affected populations must be included in decision-making to address inequities in smoke health impacts.鈥�

D’Evelyn hopes the paper will inspire more interagency and cross-disciplinary efforts and funding for research and preparation.

鈥淭here are really wonderful community organizations working to make sure that people have access to clean air. And, there are really wonderful organizations working to do as much prescribed burning as they’re allowed to lessen the smoke or lessen the severity of wildfires when they come through,鈥� D’Evelyn said. 鈥淏ut there are gaps where communities, organizations and researchers could be collaborating to have an even bigger impact on preparedness.鈥�

Other co-authors are Jihoon Jung, Ernesto Alvarado, Jill Baumgartner, Pete聽Caligiuri, R. Keala Hagmann, Sarah Henderson, Paul Hessburg, Sean Hopkins, Edward Kasner, Meg Krawchuk, Jennifer Krenz, Jamie Lydersen, Miriam E. Marlier, Yuta J. Masuda, Kerry Metlen, Susan Prichard, Claire Schollaert, Edward Smith, Jens Stevens, Christopher Tessum, Carolyn Reeb-Whitaker, Joseph Wilkins, Nicholas Wolff, Leah Wood.

For author affiliations, please see the publication.

This research was funded by Science for Nature and People Partnerships, The Nature Conservancy and CDC’s National Institute for Occupational Safety and Health.

###

For more information, contact D’Evelyn at sdevelyn@uw.edu.

Exceptionally hot and dry weather this summer has fueled dozens of wildfires across the western U.S., spewing smoke across the country and threatening to register yet another record-breaking year. More than a century of fire exclusion has created dense forests packed with excess trees and brush that ignite and spread fires quickly under increasingly warm and dry conditions.

Scientists largely agree that reducing these fuels is needed to make our forests and surrounding communities more resilient to wildfires and climate change. But policy and action have not kept pace with the problem and suppressing fires is still the norm, even as megafires become more common and destructive.

Seeing the urgent need for change, a team of scientists from leading research universities, conservation organizations and government laboratories across the West has produced a that clearly lays out the established science and strength of evidence on climate change, wildfire and forest management for seasonally dry forests. The goal is to give land managers and others across the West access to a unified resource that summarizes the best-available science so they can make decisions about how to manage their landscapes.

鈥淏ased on our extensive review of the literature and the weight of the evidence, the science of adaptive management is strong and justifies a range of time- and research-tested approaches to adapt forests to climate change and wildfires,鈥� said co-lead author Susan Prichard, a research scientist in the 91探花鈥檚 School of Environmental and Forest Sciences.

These approaches include some thinning of dense forests in fire-excluded areas, prescribed burning, reducing fuels on the ground, allowing some wildfires to burn in backcountry settings under favorable fuel and weather conditions, and revitalizing Indigenous fire stewardship practices. The were published Aug. 2 as an invited three-paper feature in the journal Ecological Applications.

The authors studied and reviewed over 1,000 published papers to synthesize more than a century of research and observations across a wide geographic range of western North American forests. The analysis didn鈥檛 include rainforests in the Pacific Northwest or other wet forests where thinning and prescribed burning wouldn鈥檛 be advised.

鈥淭he substantial changes associated with more than a century of fire exclusion jeopardize forest diversity and keystone processes as well as numerous other social and ecological values including quantity and quality of water, stability of carbon stores, air quality, and culturally important resources and food security,鈥� said co-lead author and 91探花researcher .

This ambitious set of articles was inspired by the reality that under current forest and wildfire management, massive wildfires and drought are now by far the dominant change agents of western North American forests. There is an urgent need to apply ecologically and scientifically credible approaches to forest and fire management at a pace and scale that matches the scope of the problem, the authors say.

Part of the solution involves addressing ongoing confusion over how to rectify the effects of more than a century of fire exclusion as the climate continues to warm. Land managers and policymakers recognize that the number and size of severe fires are rapidly increasing with climate change, but agreement and funding to support climate and wildfire adaptation are lagging.

To that end, these papers review the strength of the science on the benefits of adapting fire-excluded forests to a rapidly warming climate. The authors address 10 common questions, including whether management is needed after a wildfire, or whether fuel treatments (thinning, prescribed burning) work under extreme fire weather. They also discuss the need to integrate western fire science with traditional ecological knowledge and Indigenous fire uses that managed western landscapes for thousands of years.

Although climate change brings with it many uncertainties, the evidence supporting intentional forest adaptation is strong and broad based. The authors clearly demonstrate that lingering uncertainties about the future should no longer paralyze actions that can be taken today to adapt forests and communities to a warming climate and more fire.

鈥淭his collection represents a blending of scientific voices across the entire disciplinary domain,鈥� said co-lead author , a research ecologist with the U.S. Forest Service and affiliate professor at the UW. 鈥淎fter reviewing the evidence, it is clear that the changes to forest conditions and fire regimes across the West are significant. The opportunity ahead is to adapt forests to rapidly changing climatic and wildfire regimes using a wide range of available, time-tested management tools.鈥�

Co-authors on this special report are from University of Arizona, University of British Columbia, University of California, Berkeley, University of California, Merced, University of Idaho, University of Montana, University of New Mexico, Northern Arizona University, Oregon State University, The Pennsylvania State University, Utah State University, U.S. Forest Service research stations (Pacific Northwest, Pacific Southwest, Rocky Mountain), U.S. Forest Service, Pacific Southwest Region, Washington State Department of Natural Resources, California Department of Forestry and Fire Protection, U.S. Fish and Wildlife Service, U.S. Geological Survey, The Nature Conservancy, R.W. Gray Consulting, Rocky Mountain Tree-Ring Research and Spatial Informatics Group.

This research was funded by U.S. Fish and Wildlife Service, The Wilderness Society, The Nature Conservancy of Oregon, Conservation Northwest, The Ecological Restoration Institute, Washington State Department of Natural Resources, U.S. Forest Service (Pacific Northwest and Pacific Southwest Research Stations), and the California Department of Forestry and Fire Protection.

For more information, contact Prichard at sprich@uw.edu, Hessburg at paul.hessburg@usda.gov聽and Hagmann at hokulea@uw.edu

Editor’s note: Each year wildfires聽impact the landscape and change the way of life for many communities around the world. Last fall, 91探花News went to the Methow Valley — the heart of fire country — to learn more about how UW’s experts play a role in shaping how we fight and live with fires here in Washington. Here’s one story:

WINTRHOP, Wash. 鈥撀燗gencies that are well practiced in putting out wildfires are now learning a new skill: how to set the spark and fan the flames.

That’s the case for the state Department of Natural Resources, which is starting to use prescribed burning as part of its strategy for fighting wildfires.

鈥淭he DNR is good at putting out fires,鈥� said Susan Prichard, a 91探花 researcher who lives and works in the Methow Valley, an area prone to wildfires. 鈥淣ow they鈥檙e laying the groundwork to use more intentional burning in dry forests.鈥�

That鈥檚 what will happen along Wolf Creek in the Virginia Ridge Timber Sale, a 671-acre area below Sun Mountain Lodge near Winthrop, Wash. The forest has been thinned and pyres of forest debris are seasoning. They鈥檙e scheduled to burn the piles in late 2020 and are considering options for prescribed underburning of the thinned forests.

This kind of forest management is important, say key community stakeholders.

鈥淧rescribed burning is an essential tool that our community continues to look to, along with other forest management practices, to ensure our forested areas are healthy and resilient for future generations,鈥� Twisp Mayor Soo Ing-Moody said. 鈥淚 appreciate Susan鈥檚 participation at the table when it comes to sustainable best practices for forest management in our community.鈥�

The importance of forest restoration and management is vital to this region, said Jasmine Minbashian, executive director of Methow Valley Citizens Council, a conservation group.

鈥淲e want to go at it in a way that鈥檚 consistent with the latest science,鈥� Minbashian said. 鈥淪o having Susan helping us and guide us and giving us a really strong foundation of science to enable us to evaluate these projects has been hugely helpful.鈥�

How prescribed fires can play an important role in restoring forests to health is pivotal to Prichard鈥檚 work, which is gaining recognition both from her neighbors and, increasingly, a national audience. She鈥檚 been quoted in Outside Magazine, Nature and other high-profile publications.

鈥淚 like to think about fire in a complex way,鈥� she said. 鈥淲e can鈥檛 just sit back and be passive about fire.鈥� Increasingly, Prichard said, her message is: How do we work with fire?

鈥淏ecause it鈥檚 going to be here,鈥� she said. 鈥淚t鈥檚 not a matter of if, it鈥檚 when. So can we bring in some fire now to prevent the destructive fire later?鈥�

It鈥檚 a question she鈥檚 been studying for nearly two decades, using the forests around her as a laboratory. And its answers can mean a vital link between surviving wildfires and fighting off the devastation that wildfires bring, experts agree.

Before white settlers displaced Native peoples in the Methow Valley, fire was a regular part of the landscape, Prichard said. Forests were burned, either by lightning strikes or by people. It wasn鈥檛 until European settlers moved in that humans started suppressing fire, building up fuels in the forests.

Now, Prichard is advocating a return to intentional use of fire in these forests.

She鈥檚 studying the buildup of carbon 鈥� in the form of forests 鈥� and how to mitigate climate change, while restoring forests to their more natural conditions. Through the study of how past thinning and prescribed burning worked in large wildfire events, Prichard and colleagues have proven evidence that dry forest restoration, including thinning and burning, can make forests more resilient to fire with much higher tree survivorship than in untreated forests.

Prichard, 50, grew up on Whidbey Island and spent time hiking in the Cascades and Olympics. As a young teen she saw the scarred landscapes left behind by logging companies.

鈥淐lear cutting really bothered me,鈥� she said. It was then she knew that she wanted to be an environmental scientist. 鈥淭hat idea latched onto my 13-year-old brain and I never let it go.鈥�

After graduate work at the 91探花(MS 鈥�96; PHD 鈥�03), she moved to the Methow, where she conducts research as part of the and a research scientist at the 91探花School of Environmental and Forest Sciences.

In 2006, she believed the Tripod Complex Fire would be the worst she ever saw. That was before 2014 when the Carlton Complex erupted.

All the signs were there that year, Prichard said. Dry winter, hot spring, low snow pack, gusting winds.

Then, on July 17, 2014, with sustained winds of more than 35 mph, lightning struck and ignited the forest near Carlton and Cougar Flats. Fueled by the winds, 鈥渢he fires took a huge walk,鈥� Prichard said, some 40 miles to the banks of the Columbia River.

鈥淚鈥檝e never seen anything like it,鈥� she said. 鈥淭his entire valley was lit up and glowing.鈥�

Smoke rose 25,000 feet into the atmosphere. Flames destroyed more than 350 homes and burned some 256,000 acres. It remains the largest wildfire in Washington state history, running a tab of about $98 million.

But despite the destruction, there鈥檚 a flip side to fire.

鈥淔ires often are renewal agents,鈥� Prichard said. They burn accumulated fuels 鈥� the scientific term for combustible biomass in the form of live and dead vegetation 鈥� and prepare the ecosystem to start over.

That renewal can be true for people, too.

Scientific knowledge about fires also is spread over soup at the dinner table. That鈥檚 where – in pre-COVID times – neighbor and friend, Derek Van Marter, shared a meal and news of the valley.

Van Marter鈥檚 home burned in 2014, the same year of Carlton Complex Fire. Feeling trapped among smoke and debris from the massive Carlton Complex wildfire, Van Marter and his family had fled to Port Angeles for some downtime away from the smoke. That鈥檚 when another fire, the Rising Eagle Road Fire, erupted near his home.

The news that his home was destroyed came via phone calls. By the time he returned to the Methow, only burning embers remained.

鈥淲e came back and it was just a wasteland,鈥� he said. 鈥淚t was like an alien wasteland.鈥�

The house, including cats and chickens, imploded on itself just because of the heat of the fire, Van Marter said. Firefighters reported that the fire burned hotter than 2,000 degrees F.

鈥淚t was devastation,鈥� Van Marter said.

It also was a pivot point. Van Marter, his wife, daughter and dog survived the fire. They could 鈥� and did 鈥� rebuild. And today, like many in the Methow Valley, they鈥檝e rebuilt being 鈥淔ireWise.鈥�

He鈥檚 adapted his new home for fire, growing an irrigated lawn, cutting back tall shrubs and 鈥渓imbing up鈥� the nearby trees 鈥� that鈥檚 making sure the limbs are trimmed so only the tree鈥檚 canopy thrives. It鈥檚 all meant to reduce fire fuels and protect property.

Being prepared isn鈥檛 just prudent, it鈥檚 neighborly, Van Marter said. 鈥淭he more you can do as a property owner, the better neighbor you are.鈥�

Here in the Methow, that kind of fire thinking is the stuff people talk about in the grocery store. It鈥檚 also exactly what the community needs 鈥� and actively is doing, Prichard said.

鈥淚鈥檓 surrounded by fire experts,鈥� she said.

Fire here is personal and the community is deeply engaged in understanding the need for forest management.

鈥淚 believe we need to continue to have the valuable conversations needed to make informed decisions about wildfire management at the local level,鈥� Ing-Moody said. 鈥淗aving Susan here enables us to have the dialogue needed to ensure our forests are managed in a healthy way.鈥�

The 2014 Carlton Complex wildfire in north central Washington was the largest contiguous fire in state history. In just a single day, flames spread over 160,000 acres of forest and rangeland and ultimately burned more than 250,000 acres in the midst of a particularly hot, dry summer.

The wildfire, driven by strong winds and explosive growth, was unprecedented in how it burned the landscape, destroying more than 300 homes in Washington’s Methow Valley. But “megafires” like the Carlton Complex are becoming more common in western U.S. forests as the climate warms and forests are crowded with trees after years of fire exclusion.

In the first major study following the devastating Carlton Complex fire, researchers from the 91探花 and U.S. Forest Service found that previous tree thinning and prescribed burns helped forests survive the fire. The , published Feb. 22 in the journal Ecological Applications, shows that even in extreme wildfires, reducing built-up fuels such as small trees and shrubs pays off.

“Our study suggests that the fuel treatments were worth the investment, yielding a more desirable post-fire outcome than if they hadn鈥檛 been implemented,” said lead author , a research scientist at the 91探花School of Environmental and Forest Sciences. “There are a lot of benefits to creating more resilient landscapes, and this study suggests that even in the worst-case scenario wildfires, it can be worth it.”

On July 17, 2014, sustained winds of 35 mph raced through the Methow Valley, blasting oxygen into several fires that had started earlier that week. Before long, the fires joined and spread. A column of smoke stretched 30,000 feet high, dropping embers and igniting dry grasses, trees and other fuels on the ground over thousands of acres.

Propelled by the fast-moving column of smoke and wind, the flames traveled all the way to the Columbia River.

“It was the kind of fire that even experts who have studied them for decades had not seen before,” said Prichard, who lives in the Methow Valley. “It was a devastating fire for our community. I truly thought people would be killed by that fire, and it still feels miraculous that everyone survived.”

In the aftermath, Prichard and collaborators wondered if actions such as controlled burns and thinning were helpful in the case of a megafire like the Carlton Complex. State and federal agencies sink ample resources into these efforts to increase the resiliency of forests to wildfires by removing small- and medium-sized trees, leaving larger, mature trees that are more likely to survive future drought and wildfires.

After a forest is thinned, prescribed burning is used to reduce leftover woody debris on logging sites or across landscapes that have built up downed trees, pine needles, grasses and shrubs.

The Carlton Complex fire burned across hundreds of sites that were previously thinned or burned, offering a testbed for the researchers to analyze whether the work helped reduce fire impacts in those areas during the megafire. The researchers used satellite images of burn severity to examine how past fuel treatments performed in the context of this extreme wildfire event.

They found that even during the first explosive days of the Carlton Complex, areas that were thinned and prescribed burned had more trees survive than areas that didn’t receive those fuel treatments.

“Some of the treatments measurably reduced fire impacts even under very hot, dry and windy conditions,” said co-author , a research scientist at U.S. Forest Service Wenatchee Forestry Sciences Lab. “Our results suggest that as we increase our ‘restoration footprint’ 鈥� the proportion of forest area treated to reduce fuels 鈥� forests may become increasingly resilient to wildfires under a broad range of conditions.”

They also found that thinning and burning on slopes that were protected from prevailing winds was more effective in reducing the wildfire’s impacts on the landscape than similar treatments in areas directly exposed to the wind. Because winds often move through the Methow Valley in a predictable pattern, fire managers could thin and burn strategically in areas where these activities would be most effective.

Those efforts helped mature, naturally fire-resistant ponderosa pines survive. These mature trees, in turn, will provide seeds that produce younger trees across the landscape.

While this study focused on the Carlton Complex fire, its results have broader implications for forests around the world that are prone to wildfires. This work adds to the growing library of studies showing how thinning trees and controlled burns can reduce the severity of the next fire on the landscape.

“I鈥檓 hopeful our study will encourage policymakers as well as managers to invest in restoration,” Prichard said. “It’s our best hope for protecting our streams, rivers and landscapes from catastrophic fires.”

Other co-authors are , assistant professor at 91探花Tacoma, and , research scientist at U.S. Forest Service Wenatchee Forestry Sciences Lab.

This research was funded by the U.S. Forest Service’s Western Wildland Environmental Threat Assessment Center, the Joint Fire Science Program and the National Fire Plan.

For more information, contact Prichard at sprich@uw.edu and Peterson at dave.peterson@usda.gov.

It’s hard to find a place in the U.S. that isn’t impacted by wildfires and smoke.

Dry landscapes, warmer temperatures and more development near forested areas all contribute to massive wildfires across North America each year. Smoke and haze from these fires can travel hundreds of miles from their source, affecting the health and wellbeing of communities across the U.S.

Given these impacts, scientists rely on models that try to predict the severity of wildfires and smoke. The amount of living and dead vegetation on a landscape, known as fuels, is a key part of the equation when modeling wildfire and smoke behavior. But in many areas, fuel estimates are imprecise, leading to unreliable smoke and fire forecasts 鈥� potentially endangering communities.

Researchers from the 91探花 and Michigan Technological University have created the first comprehensive database of all the wildfire fuels that have been measured across North America. Called the , the tool incorporates the best available measurements of vegetation in specific locations, and allows fire managers to see where information about fuels is missing altogether.

Ultimately, it can help scientists make more informed decisions about fire and smoke situations.

“Where there are fuels and fire, there’s smoke,” said lead author , a research scientist at the 91探花School of Environmental and Forest Sciences. “This database is informing more realistic predictions of smoke that allow for the fact that we might not have dialed in the fuels perfectly.”

The new database is described in a published Dec. 4 in the Journal of Geophysical Research 鈥� Biogeosciences.

There are many types of vegetation that burn during wildfires, including live and dead trees, freshly fallen leaves and needles, shrubs, grasses, moss 鈥� and even decomposing logs and soil. The database, which includes a map view, shows a breakdown of each type of wildfire fuel and its amount in various locations across the U.S. It provides, for example, a quick way to see that dead trees are more densely packed along the West Coast, while decomposing materials, called “duff,” are more prevalent along the East Coast and upper Midwest.

The amount of vegetation in a particular area can vary drastically by season and natural events like windstorms that blow down trees, or wildfires that burn up fuels on the ground. As a result, the researchers found that it takes a wide range of observations to encompass the natural variability that is common within vegetation on a landscape.

Their dataset incorporates all of the existing information about fuels across the country 鈥� drawn from other datasets and published studies 鈥� and also factors in the potential range of variability for each vegetation type in different locations.

“Setting a static map of fuels is not going to be an accurate depiction of what the vegetation will be like in that location forever,” said co-author , an assistant professor at 91探花Tacoma. “It was important to us to find ways to communicate that fuels on the landscape are variable and have uncertainty.”

The researchers hope that smoke modelers and fire managers use this data to analyze the range of wildfire fuels in their location, and use it to make better predictions about smoke emissions and fire severity. All of the data is accessible and downloadable from their website.

Managers also could use this data when deciding where and when to do a prescribed burn, which is important for reducing fire hazard in dense forests. More accurate fuels information will help determine if smoke and other pollutants will be too high or within a safe range for surrounding communities during a burn.

The team also hopes to add more data as other researchers continue to take measurements of the fuels in their areas. Data on live and dead trees is robust because of satellite imagery, Prichard explained, but data on fuels that must be measured by hand, such as leaves, needles and small branches, are largely missing. Fuels all burn differently 鈥� some smolder while others ignite quickly 鈥� which can also impact the accuracy of smoke and fire predictions.

“One of the things we didn’t anticipate is that the database would also let us know what still needs to be done,” Prichard said. “The big surprise for all of us is how little data we have on non-forest vegetation such as grasslands and shrublands. That data gap is big and worth closing over time.”

Other co-authors are Anne Andreu and Paige Eagle, research scientists at the 91探花School of Environmental and Forest Sciences, and Nancy French and Michael Billmire of Michigan Technological University.

This research was funded by the Joint Fire Science Program and the U.S. Forest Service Pacific Northwest Research Station.

For more information, contact Prichard at sprich@uw.edu and Kennedy at mkenn@uw.edu.