Research Database
Displaying 81 - 100 of 177
Where and why do conifer forests persist in refugia through multiple fire events?
Year: 2021
Changing wildfire regimes are causing rapid shifts in forests worldwide. In particular, forested landscapes that burn repeatedly in relatively quick succession may be at risk of conversion when pre-fire vegetation cannot recover between fires. Fire refugia (areas that burn less frequently or severely than the surrounding landscape) support post-fire ecosystem recovery and the persistence of vulnerable species in fire-prone landscapes. Observed and projected fire-induced forest losses highlight the need to understand where and why forests persist in refugia through multiple fires. This…
Publication Type: Journal Article
Wildfire and climate change adaptation of western North American forests: a case for intentional management
Year: 2021
We review science-based adaptation strategies for western North American (wNA) forests that include restoring active fire regimes and fostering resilient structure and composition of forested landscapes. As part of the review, we address common questions associated with climate adaptation and realignment treatments that run counter to a broad consensus in the literature. These include the following: (1) Are the effects of fire exclusion overstated? If so, are treatments unwarranted and even counterproductive? (2) Is forest thinning alone sufficient to mitigate wildfire hazard? (3) Can forest…
Publication Type: Journal Article
Forest Restoration and Fuels Reduction: Convergent or Divergent?
Year: 2021
For over 20 years, forest fuel reduction has been the dominant management action in western US forests. These same actions have also been associated with the restoration of highly altered frequent-fire forests. Perhaps the vital element in the compatibility of these treatments is that both need to incorporate the salient characteristics that frequent fire produced—variability in vegetation structure and composition across landscapes and the inability to support large patches of high-severity fire. These characteristics can be achieved with both fire and mechanical treatments. The possible key…
Publication Type: Journal Article
Forest Roads and Operational Wildfire Response Planning
Year: 2021
Supporting wildfire management activities is frequently identified as a benefit of forestroads. As such, there is a growing body of research into forest road planning, construction, andmaintenance to improve fire surveillance, prevention, access, and control operations. Of interesthere is how road networks directly support fire control operations, and how managers incorporatethat information into pre-season assessment and planning. In this communication we briefly reviewand illustrate how forest roads relate to recent advances in operationally focused wildfire decisionsupport. We focus on two…
Publication Type: Journal Article
Fire and Forests in the 21st Century: Managing Resilience Under Changing Climates and Fire Regimes in USA Forests
Year: 2021
Higher temperatures, lower snowpacks, drought, and extended dry periods have contributed to increased wildfire activity in recent decades. Climate change is expected to increase the frequency of large fires, the cumulative area burned, andfire suppression costs and risks in many areas of the USA. Fire regimes are likely to change due to interactions among climate, fire, and other stressors and disturbances; resulting in persistent changes in forest structure and function. The remainder of the twenty-first century will present substantial challenges, as natural resource managers are faced with…
Publication Type: Book Chapter
Persistent effects of fire severity on ponderosa pine regeneration niches and seedling growth
Year: 2020
Several recent studies have documented how fire severity affects the density and spatial patterns of tree regenerationin western North American ponderosa pine forests. However, less is known about the effects of fireseverity on fine-scale tree regeneration niche attributes such as understory plant composition and cover, surfacefuel abundance, and soil properties, or how these attributes in turn affect regenerating ponderosa pine growth.Using 1-m2 plots centered on 360 ponderosa pine seedlings that regenerated naturally after the Pumpkin Fire in2000 in Arizona, we quantified regeneration niche…
Publication Type: Journal Article
How does tree regeneration respond to mixed‐severity fire in the western Oregon Cascades, USA?
Year: 2020
Dendroecological studies of historical tree recruitment patterns suggest mixed‐severity fire effects are common in Douglas‐fir/western hemlock forests of the Pacific Northwest (PNW), USA, but empirical studies linking observed fire severity to tree regeneration response are needed to expand our understanding into the functional role of fire in this forest type. Recent increases in mixed‐severity fires offered this opportunity, so we quantified the abundance, spatial distribution, species richness, and community composition of regenerating trees across a mixed‐severity fire gradient (unburned–…
Publication Type: Journal Article
Disjunct and decoupled? The persistence of a fire-sensitive conifer soecies in a historically frequent-fire landscape
Year: 2020
Local and regional species extirpations may become more common as changing climate and disturbance regimesaccelerate species’ in situ range contractions. Identifying locations that function as both climate and disturbancerefugia is critical for biodiversity conservation. Here, we investigate the persistence of a disjunct, fire-sensitiveconifer population, yellow-cedar (Callitropsis nootkatensis), in the historically frequent-fire landscape of the BlueMountains in eastern Oregon, USA. We used tree rings to reconstruct multi-century fire histories, which werethen used to compare historical mean…
Publication Type: Journal Article
Washington State 2020 Forest Action Plan
Year: 2020
Washington has more than 22 million acres of forestland. From the lush rainforests on our coasts, to the rugged sub-alpine forests along the Cascade Crest, to the pine-dominated hillsides surrounding the Columbia Plateau, forests are an integral part of our landscapes and communities, and they provide a wealth of benefits to Washingtonians and the planet. They provide us with sustainable timber and jobs, produce clean air and water, sequester carbon, and support world-class outdoor recreation. Our forests, however, face unprecedented threats that require bold action. Climate change is…
Publication Type: Government Report
Fostering collective action to reduce wildfire risk across property boundaries in the American West
Year: 2020
Large-scale, high-severity wildfires are a major challenge to the future social-ecological sustainability of fire-adapted forest ecosystems in the American West. Managing forests to mitigate this risk is a collective action problem requiring landowners and stakeholders within multi-ownership landscapes to plan and implement coordinated restoration treatments. Our research question is: how can we promote collective action to reduce wildfire risk and restore fire-resilient forests in the American West? To address this question we draw on collective action theory to produce an environmental…
Publication Type: Journal Article
Potential COVID-19 Outbreak in Fire Camp: Modeling Scenarios and Interventions
Year: 2020
The global COVID-19 pandemic will pose unique challenges to the management of wildlandfire in 2020. Fire camps may provide an ideal setting for the transmission of SARS-CoV-2, the virusthat causes COVID-19. However, intervention strategies can help minimize disease spread andreduce the risk to the firefighting community. We developed a COVID-19 epidemic model tohighlight the risks posed by the disease during wildland fire incidents. Our model accounts forthe transient nature of the population on a wildland fire incident, which poses unique risks to themanagement of communicable diseases in…
Publication Type: Journal Article
Tribes & Climate Change
Year: 2020
Native Americans rely on tribally important ecosystem services such as traditional foods, hunting, timber production, non-timber forest resources (recreation, water), and cultural resources. Unfortunately, many of these resources may be highly vulnerable to the impacts of climate change. A research team sought to answer the question: Where and which tribally-important ecosystem services will be affected by climate change in the Pacific Northwest? They used projections from climate and vegetation models and stakeholder input to demonstrate a generalizable approach for assessing possible…
Publication Type: Web project page
Wildland firefighter smoke exposure and risk of lung cancer and cardiovascular disease mortality
Year: 2019
Wildland firefighters are exposed to wood smoke, which contains hazardous air pollutants, by suppressing thousands of wildfires across the U. S. each year. We estimated the relative risk of lung cancer and cardiovascular disease mortality from existing PM2.5 exposure-response relationships using measured PM4 concentrations from smoke and breathing rates from wildland firefighter field studies across different exposure scenarios. To estimate the relative risk of lung cancer (LC) and cardiovascular disease (CVD) mortality from exposure to PM2.5 from smoke, we used an existing exposure-response…
Publication Type: Journal Article
A Classification of US Wildland Firefighter Entrapments Based on Coincident Fuels, Weather, and Topography
Year: 2019
Previous attempts to identify the environmental factors associated with firefighter entrapments in the United States have suggested that there are several common denominators. Despite the widespread acceptance of the assumed commonalities, few studies have quantified how often entrapments actually meet these criteria. An analysis of the environmental conditions at the times and locations of 166 firefighter entrapments involving 1202 people and 117 fatalities that occurred between 1981 and 2017 in the conterminous United States revealed some surprising results. Contrary to general assumptions…
Publication Type: Journal Article
Fire deficits have increased drought‐sensitivity in dry conifer forests; fire frequency and tree‐ring carbon isotope evidence from Central Oregon
Year: 2019
A century of fire suppression across the Western US has led to more crowded forests and increased competition for resources. Studies of forest thinning or stand conditions after mortality events have provided indirect evidence for how competition can promote drought stress and predispose forests to severe fire and/or bark beetle outbreaks. Here we demonstrate linkages between fire deficits and increasing drought stress through analyses of annually resolved tree‐ring growth, fire scars, and carbon isotope discrimination (Δ13C) across a dry mixed‐conifer forest landscape. Fire deficits across…
Publication Type: Journal Article
Post-fire management affects species composition but not Douglas-fir regeneration in the Klamath Mountains
Year: 2019
Ensuring adequate conifer regeneration after high severity wildfires is a common objective for ecologists and forest managers. In the Klamath region of Oregon and California, a global hotspot of botanical biodiversity, concerns over regeneration have led to post-fire management on many sites, which involves salvage logging followed by site preparation, conifer planting, and manual shrub release. To quantify the impacts of post-fire management, we sampled 62 field sites that burned at high severity nearly 20 years ago in the Klamath-Siskiyou Mountain bioregion, stratifying by management and…
Publication Type: Journal Article
Factors Associated with Structure Loss in the 2013–2018 California Wildfires
Year: 2019
Tens of thousands of structures and hundreds of human lives have been lost in recent fire events throughout California. Given the potential for these types of wildfires to continue, the need to understand why and how structures are being destroyed has taken on a new level of urgency. We compiled and analyzed an extensive dataset of building inspectors’ reports documenting homeowner mitigation practices for more than 40,000 wildfire-exposed structures from 2013–2018. Comparing homes that survived fires to homes that were destroyed, we investigated the role of defensible space distance,…
Publication Type: Journal Article
Rethinking resilience to wildfire
Year: 2019
Record-breaking fire seasons are becoming increasingly common worldwide, and large wildfires are having extraordinary impacts on people and property, despite years of investments to support social–ecological resilience to wildfires. This has prompted new calls for land management and policy reforms as current land and fire management approaches have been unable to effectively respond to the rapid changes in climate and development patterns that strongly control fire behaviour and continue to exacerbate the risks and hazards to human communities. Promoting social–ecological resilience in…
Publication Type: Journal Article
Out of the Ashes: Ecological Resilience to Extreme Wildfire, Prescribed Burns, and Indigenous Burning in Ecosystems
Year: 2019
Until Euro-American colonization, Indigenous people used fire to modify eco-cultural systems, developing robust Traditional Ecological Knowledge (TEK). Since 1980, wildfire activity has increased due to fire suppression and climate change. In 2017, in Waterton Lakes National Park, AB, the Kenow wildfire burned 19,303 ha, exhibiting extreme fire behavior. It affected forests and the Eskerine Complex, a native-grass prairie treated with prescribed burns since 2006 to reduce aspen (Populus tremuloides) encroachment linked to fire suppression and bison (Bison bison bison) extirpation. One year…
Publication Type: Journal Article
Tamm Review: Reforestation for resilience in dry western U.S. forests
Year: 2019
The increasing frequency and severity of fire and drought events have negatively impacted the capacity and success of reforestation efforts in many dry, western U.S. forests. Challenges to reforestation include the cost and safety concerns of replanting large areas of standing dead trees, and high seedling and sapling mortality rates due to water stress, competing vegetation, and repeat fires that burn young plantations. Standard reforestation practices have emphasized establishing dense conifer cover with gridded planting, sometimes called 'pines in lines', followed by shrub control and pre-…
Publication Type: Journal Article