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Research Database

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Strategies to reduce wildfire smoke in frequently impacted communities in south-western Oregon

Year: 2022
Background: Efforts to mitigate the adverse effects of wildfire smoke have focused on modifying human behaviour to minimise individual exposure, largely accomplished by providing smoke forecasts, monitoring, and consistent public messaging. Aims: To identify a strategy to reduce the amount of wildfire smoke in frequently impacted communities. Methods: We identify frequent air pathways that transport smoke into five communities in south-western Oregon. We present a case study comparing the potential change in the 24-h average PM2.5 concentration between fuels burned during a wildfire which are…
Smoke and Air Quality, Social and Community Impacts of Fire
public health
Publication Type: Journal Article

Post-fire landscape evaluations in Eastern Washington, USA: Assessing the work of contemporary wildfires

Year: 2022
In the western US, wildfires are modifying the structure, composition, and patterns of forested landscapes at ratesthat far exceed mechanical thinning and prescribed fire treatments. There are conflicting narratives as to whetherthese wildfires are restoring landscape resilience to future climate and wildfires. To evaluate the landscape-levelwork of wildfires, we assessed four subwatersheds in eastern Washington, USA that experienced large wildfires in2014, 2015, or 2017 after more than a century of fire exclusion and extensive timber harvest. We compared preandpost-fire landscape conditions…
Fire Effects and Fire Ecology, Restoration and Hazardous Fuel Reduction
fire severity, post-fire
Publication Type: Journal Article

More smoke today for less smoke tomorrow? We need to better understand the public health benefits and costs of prescribed fire

Year: 2022
Rapidly scaling up the use of prescribed fire is being promoted as an important pathway for reducing the growing damages of wildfire events in the United States, including limiting the health impacts from smoke emissions. However, we do not currently have the science needed to understand how the health impacts associated with prescribed fire smoke in the present compare to wildfire smoke exposure in the future. In particular, we lack an understanding of how the potential long-term public health benefits of prescribed fire on future wildfire smoke and health impacts compare to prescribed fire’…
Prescribed Burning, Smoke and Air Quality
public health, management
Publication Type: Journal Article

Oregon Wildfire Smoke Communications and Impacts: An Evaluation of the 2020 Wildfire Season

Year: 2022
Oregon Health Authority and the University of Oregon partnered to conduct a survey-based evaluation of wildfire smoke communications and impacts experienced by Oregon residents during the 2020 wildfire season. The purpose of this survey was to (1) understand how Oregonians respond to wildfire smoke and (2) provide an open-source evaluation tool and data to support wildfire smoke communication practitioners in Oregon.
Public Perceptions of Fire and Smoke, Social and Community Impacts of Fire
public health
Publication Type: Journal Article

Wildfire, Smoke Exposure, Human Health, and Environmental Justice Need to be Integrated into Forest Restoration and Management

Year: 2022
Purpose of Review: Increasing wildfire size and severity across the western United States has created an environmental and social crisis that must be approached from a transdisciplinary perspective. Climate change and more than a century of fire exclusion and wildfire suppression have led to contemporary wildfires with more severe environmental impacts and human smoke exposure. Wildfires increase smoke exposure for broad swaths of the US population, though outdoor workers and socially disadvantaged groups with limited adaptive capacity can be disproportionally exposed. Exposure to wildfire…
Prescribed Burning, Restoration and Hazardous Fuel Reduction
collaboration, public health
Publication Type: Journal Article

Increasing co-occurrence of fine particulate matter and ground-level ozone extremes in the western United States

Year: 2022
Wildfires and meteorological conditions influence the co-occurrence of multiple harmful air pollutants including fine particulate matter (PM2.5) and ground-level ozone. We examine the spatiotemporal characteristics of PM2.5/ ozone co-occurrences and associated population exposure in the western United States (US). The frequency, spatial extent, and temporal persistence of extreme PM2.5/ozone co-occurrences have increased significantly between 2001 and 2020, increasing annual population exposure to multiple harmful air pollutants by ~25 million person-days/year. Using a clustering methodology…
Smoke and Air Quality
emissions, public health
Publication Type: Journal Article

Wildfire controls on land surface properties in mixed conifer and ponderosa pine forests of Sierra Nevada and Klamath mountains, Western US

Year: 2022
This study examines the post-fire biogeophysical and biochemical dynamics after several high-severity wildfires that occurred in mixed conifer and ponderosa pine forest types in the Sierra Nevada and Klamath Mountains regions between 1986 and 2017. We found a consistent pattern of reduced leaf area index (LAI) in the first year after fire, followed by gradual recovery over the subsequent 25 years. Recovery rate varied between forest types. For example, average summer LAI for 16-25 years post-fire was 88% of the pre-fire average for mixed conifers in the Sierra Nevada, 64% for ponderosa pine…
Fire Effects and Fire Ecology
post-fire, remote sensing, ponderosa pine
Publication Type: Journal Article

Roles and experiences of non-governmental organisations in wildfire response and recovery

Year: 2021
Local non-governmental organisations (NGOs) play critical roles in providing immediate relief resources and long-term recovery support for communities after a disaster. Drawing on interviews with NGO representatives involved in three Northern California wildfires in 2017 and 2018, this study identifies challenges and opportunities for NGOs supporting wildfire relief and recovery. Across fires andNGOs,NGOmanagement and wellbeing, coordination and disaster experiences emerge as common barriers and enablers of relief and recovery. In many cases, local NGOs’ participation in wildfire relief and…
Social and Community Impacts of Fire
resilience, post-fire
Publication Type: Journal Article

Field measurements of PM2.5 infiltration factor and portable air cleaner effectiveness during wildfire episodes in US residences

Year: 2021
Wildfires have frequently occurred in the western United States (US) during the summer and fall seasons in recent years. This study measures the PM2.5 infiltration factor in seven residences recruited from five dense communities in Seattle, Washington, during a 2020 wildfire episode and evaluates the impacts of HEPA-based portable air cleaner (PAC) use on reducing indoor PM2.5 levels. All residences with windows closed went through an 18-to-24-h no filtration session, with five of seven following that period with an 18-to-24-h filtration session. Auto-mode PACs, which automatically adjust the…
Smoke and Air Quality
public health
Publication Type: Journal Article

Episodic occurrence of favourable weather constrains recovery of a cold desert shrubland after fire

Year: 2021
1. Key to the long-term resilience of dryland ecosystems is the recovery of foundation plant species following disturbance. In ecosystems with high interannual weather variability, understanding the influence of short-term environmental conditions on establishment of foundation species is essential for identifying vulnerable landscapes and developing restoration strategies. We asked how annual environmental conditions affect post-fire establishment of Artemisia tridentata, a shrub species that dominates landscapes across much of the western United States, and evaluated the influence of…
Prescribed Burning, Restoration and Hazardous Fuel Reduction
sagebrush, weather, post-fire
Publication Type: Journal Article

Wildfire recovery as a “hot moment” for creating fire-adapted communities

Year: 2020
Recent decades have witnessed an escalation in the social, economic, and ecological impacts of wildfires worldwide. Wildfire losses stem from the complex interplay of social and ecological forces at multiple scales, including global climate change, regional wildfire regimes altered by human activities, and locally managed wildland-urban interface (WUI) zones where homes increasingly encroach upon wildland vegetation. The coupled nature of the human-ecological system is precisely what makes reducing wildfire risks challenging. As losses from wildfire have accelerated, an emerging research and…
Public Perceptions of Fire and Smoke, Social and Community Impacts of Fire
post-fire, modeling, adaptation
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–…
Fire Effects and Fire Ecology, Restoration and Hazardous Fuel Reduction
resilience, fire severity, regeneration, post-fire
Publication Type: Journal Article

Effects of post-fire management on dead woody fuel dynamics and stand structure in a severely burned mixed-conifer forest, in northeastern Washington State, USA

Year: 2020
The increasing amount of high-severity wildfire in historical low and mixed-severity fire regimes in western US forests has created a need to better understand the ecological effects of different post fire management approaches. For three different salvage prescriptions, we quantified change in stand structural metrics (snag densities and snag basal areas), dead woody fuel loadings, tree regeneration survival, and percentage change in vegetation cover before and after post-fire logging 1 year after the 2015 Stickpin Wildfire on the Colville National Forest in northeastern Washington State, USA. In a…
Mixed-Conifer Management, Soils and Woody Debris
post-fire, management
Publication Type: Journal Article

Wildfire severity and postfire salvage harvest effects on long-term forest regeneration

Year: 2020
Following a wildfire, regeneration to forest can take decades to centuries and is no longerassured in many western U.S. environments given escalating wildfire severity and warming trends. Afterlarge fire years, managers prioritize where to allocate scarce planting resources, often with limited informationon the factors that drive successful forest establishment. Where occurring, long-term effects of postfiresalvage operations can increase uncertainty of establishment. Here, we collected field data on postfireregeneration patterns within 13- to 28-yr-old burned patches in eastern Washington…
Fire Effects and Fire Ecology
fire severity, regeneration, post-fire
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…
Fire Effects and Fire Ecology, Mixed-Conifer Management
resilience, regeneration, post-fire, management
Publication Type: Journal Article

Evaluating Model Predictions of Fire Induced Tree Mortality Using Wildfire-Affected Forest Inventory Measurements

Year: 2019
Forest land managers rely on predictions of tree mortality generated from fire behavior models to identify stands for post-fire salvage and to design fuel reduction treatments that reduce mortality. A key challenge in improving the accuracy of these predictions is selecting appropriate wind and fuel moisture inputs. Our objective was to evaluate postfire mortality predictions using the Forest Vegetation Simulator Fire and Fuels Extension (FVS-FFE) to determine if using representative fire-weather data would improve prediction accuracy over two default weather scenarios. We used pre- and post-…
Fire Effects and Fire Ecology
fire behavior, post-fire, tree mortality
Publication Type: Journal Article

Influence of fire refugia spatial pattern on post-fire forest recovery in Oregon’s Blue Mountains

Year: 2019
Context Fire regimes in many dry forests of western North America are substantially different from historical conditions, and there is concern about the ability of these forests to recover following severe wildfire. Fire refugia, unburned or low-severity burned patches where trees survived fire, may serve as essential propagule sources that enable forest regeneration. Objectives To quantify the influence of fire refugia spatial pattern and other biophysical factors on the process of post-fire tree regeneration; in particular examining both the proximity and density of surrounding refugia to…
Fire Effects and Fire Ecology, Mixed-Conifer Management
fire refugia, resilience, regeneration, post-fire
Publication Type: Journal Article

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…
Smoke and Air Quality
public health, fire suppression
Publication Type: Journal Article

Tree regeneration following wildfires in the western US: a review

Year: 2019
Background: Wildfires, like many disturbances, can be catalysts for ecosystem change. Given projected climate change, tree regeneration declines and ecosystem shifts following severe wildfires are predicted. We reviewed scientific literature on post-fire tree regeneration to understand where and why no or few trees established. We wished to distinguish sites that won’t regenerate to trees because of changing climate from sites where trees could grow post fire if they had a seed source or were planted, thus supporting forest ecosystem services for society and nature, such as timber supply,…
Fire Effects and Fire Ecology
post-fire
Publication Type: Journal Article

Air-quality challenges of prescribed fire in the complex terrain and wildland urban interface surrounding Bend, Oregon

Year: 2019
Prescribed fires in forest ecosystems can negatively impact human health and safety by transporting smoke downwind into nearby communities. Smoke transport to communities is known to occur around Bend, Oregon, United States of America (USA), where burning at the wildland–urban interface in the Deschutes National Forest resulted in smoke intrusions into populated areas. The number of suitable days for prescribed fires is limited due to the necessity for moderate weather conditions, as well as wind directions that do not carry smoke into Bend. To better understand the conditions leading to…
Prescribed Burning, Smoke and Air Quality
modeling, public health
Publication Type: Journal Article