Research Database
Displaying 61 - 80 of 174
Social Vulnerability in USCommunities Affected by WildfireSmoke, 2011 to 2021
Year: 2023
Objectives. To describe demographic and social characteristics of US communities exposed to wildfire smoke.
Methods. Using satellite-collected data on wildfire smoke with the locations of population centers in the coterminous United States, we identified communities potentially exposed to light-, medium-, and heavy-density smoke plumes for each day from 2011 to 2021. We linked days of exposure to smoke in each category of smoke plume density with 2010 US Census data and community characteristics from the Centers for Disease Control and Prevention’s Social Vulnerability Index to describe…
Publication Type: Journal Article
A comparison of smoke modelling tools used to mitigate air quality impacts from prescribed burning
Year: 2023
Background. Prescribed fire is a land management tool used extensively across the United States. Owing to health and safety risks, smoke emitted by burns requires appropriate manage- ment. Smoke modelling tools are often used to mitigate air pollution impacts. However, direct comparisons of tools’ predictions are lacking. Aims. We compared three tools commonly used to plan prescribed burning projects: the Simple Smoke Screening Tool, VSmoke and HYSPLIT. Methods. We used each tool to model smoke dispersion from prescribed burns conducted by the North Carolina Division of Parks and Recreation…
Publication Type: Journal Article
Exposure to wildfires and health outcomes of vulnerable people: Evidence from US data
Year: 2023
This paper investigates the causal effect of wildfire exposure on birth outcomes and older people’s health outcomes in United States (US). The study focuses on three sub-questions for each health outcome: (1) the causal effect of each of the five largest wildfires on individual health, (2) the causal impact of multiple large wildfires on individual health outcomes, and (3) the causal influence of wildfires larger than different sizes within different distances of counties on health outcomes at the county level. The analysis exploits data from National Vital Statistics System, Behavioural Risk…
Publication Type: Journal Article
Shaded fuel breaks create wildfire-resilient forest stands: lessons from a long-term study in the Sierra Nevada
Year: 2023
Background In California’s mixed-conifer forests, fuel reduction treatments can successfully reduce fire severity, bolster forest resilience, and make lasting changes in forest structure. However, current understanding of the duration of treatment effectiveness is lacking robust empirical evidence. We leveraged data collected from 20-year-old forest monitoring plots within fuel treatments that captured a range of wildfire occurrence (i.e., not burned, burned once, or burned twice) following initial plot establishment and overstory thinning and prescribed fire treatments. Results Initial…
Publication Type: Journal Article
Terrestrial carbon dynamics in an era of increasing wildfire
Year: 2023
In an increasingly flammable world, wildfire is altering the terrestrial carbon balance. However, the degree to which novel wildfire regimes disrupt biological function remains unclear. Here, we synthesize the current understanding of above- and belowground processes that govern carbon loss and recovery across diverse ecosystems. We find that intensifying wildfire regimes are increasingly exceeding biological thresholds of resilience, causing ecosystems to convert to a lower carbon-carrying capacity. Growing evidence suggests that plants compensate for fire damage by allocating carbon…
Publication Type: Journal Article
Social vulnerability of the people exposed to wildfires in U.S. West Coast states
Year: 2023
Understanding of the vulnerability of populations exposed to wildfires is limited. We used an index from the U.S. Centers for Disease Control and Prevention to assess the social vulnerability of populations exposed to wildfire from 2000–2021 in California, Oregon, and Washington, which accounted for 90% of exposures in the western United States. The number of people exposed to fire from 2000–2010 to 2011–2021 increased substantially, with the largest increase, nearly 250%, for people with high social vulnerability. In Oregon and Washington, a higher percentage of exposed people were highly…
Publication Type: Journal Article
The outsized role of California’s largest wildfires in changing forest burn patterns and coarsening ecosystem scale
Year: 2023
Highlights • We evaluated trends for 1,809 fires that burned 1985–2020 across California forests. • Top 1% of fires by size burned 47% of total area burned across the study period. • Top 1% (18 fires) produced 58% of high and 42% of low-moderate severity area. • Top 1% created novel landscape patterns of large burn severity patches. • These large fires create new opportunities for managing forest resilience. Although recent large wildfires in California forests are well publicized in media and scientific literature, their cumulative effects on forest structure and implications for forest…
Publication Type: Journal Article
Community Forests advance local wildfire governance and proactive management in British Columbia, Canada
Year: 2023
As wildfires are increasingly causing negative impacts to communities and their livelihoods, many communities are demanding more proactive and locally driven approaches to address wildfire risk. This marks a shift away from centralized governance models where decision-making is concentrated in government agencies that prioritize reactive wildfire suppression. In British Columbia (BC), Canada, Community Forests—a long-term, area-based tenure granted to Indigenous and/or local communities—are emerging as local leaders facilitating proactive wildfire management. To explore the factors that are…
Restoration and Hazardous Fuel Reduction, Risk Assessment and Analysis, Social and Community Impacts of Fire
Publication Type: Journal Article
Quantifying the smoke-related public health trade-offs of forest management
Year: 2023
Prescribed burning can mitigate extreme wildfire risk and reduce total smoke emissions. Yet prescribed burns’ emissions may also contribute to smoke exposures in nearby communities. Incorporating public health considerations into forest management planning efforts may help reduce prescribed burn-related exposure impacts. We present a methodological framework linking landscape ecology, air-quality modelling and health impact assessment to quantify the air-quality and health impacts of specific management strategies. We apply this framework to six forest management scenarios proposed for a…
Publication Type: Journal Article
Less fuel for the next fire? Short-interval fire delays forest recovery and interacting drivers amplify effects
Year: 2023
As 21st-century climate and disturbance dynamics depart from historic baselines, ecosystem resilience is uncertain. Multiple drivers are changing simultaneously, and interactions among drivers could amplify ecosystem vulnerability to change. Subalpine forests in Greater Yellowstone (Northern Rocky Mountains, USA) were historically resilient to infrequent (100–300 year), severe fire. We sampled paired short-interval (<30-year) and long-interval (>125-year) post-fire plots most recently burned between 1988 and 2018 to address two questions: (1) How do short-interval fire, climate,…
Publication Type: Journal Article
Old reserves and ancient buds fuel regrowth of coast redwood after catastrophic fire
Year: 2023
For long-lived organisms, investment in insurance strategies such as reserve energy storage can enable resilience to resource deficits, stress or catastrophic disturbance. Recent fire in California damaged coast redwood (Sequoia sempervirens) groves, consuming all foliage on some of the tallest and oldest trees on Earth. Burned trees recovered through resprouting from roots, trunk and branches, necessarily supported by nonstructural carbon reserves. Nonstructural carbon reserves can be many years old, but direct use of old carbon has rarely been documented and never in such large, old trees.…
Publication Type: Journal Article
The persistence of smoke VOCs indoors: Partitioning, surface cleaning, and air cleaning in a smoke-contaminated house
Year: 2023
Wildfires are increasing in frequency, raising concerns that smoke can permeate indoor environments and expose people to chemical air contaminants. To study smoke transformations in indoor environments and evaluate mitigation strategies, we added smoke to a test house. Many volatile organic compounds (VOCs) persisted days following the smoke injection, providing a longer-term exposure pathway for humans. Two time scales control smoke VOC partitioning: a faster one (1.0 to 5.2 hours) that describes the time to reach equilibrium between adsorption and desorption processes and a slower one (4.8…
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…
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…
Publication Type: Journal Article
Cultivating Collaborative Resilience to Social and Ecological Change: An Assessment of Adaptive Capacity, Actions, and Barriers Among Collaborative Forest Restoration Groups in the United States
Year: 2022
Collaboration is increasingly emphasized as a tool to realize national-level policy goals in public lands management. Yet, collaborative governance regimes (CGRs) are nested within traditional bureaucracies and are affected by internal and external disruptions. The extent to which CGRs adapt and remain resilient to these disruptions remains under-explored. Here, we distill insights from an assessment of the Collaborative Forest Landscape Restoration Program (CFLRP) projects and other CGRs. We asked (1) how do CGRs adapt to disruptions? and (2) what barriers constrained CGR resilience? Our…
Publication Type: Journal Article
Comparing particulate morphology generated from human-made cellulosic fuels to natural vegetative fuels
Year: 2022
Background: In wildland–urban interface (WUI) fires, particulates from the combustion of both natural vegetative fuels and engineered cellulosic fuels may have deleterious effects on the environment. Aims: The research was conducted to investigate the morphology of the particulate samples generated from the combustion of oriented strand board (OSB). Findings were compared to the particulate samples collected from the combustion of noble-fir branches. Methods: The exposure conditions were varied to induce either smouldering combustion or flaming combustion of the specimens. Particulate samples…
Publication Type: Journal Article
Comparing particulate morphology generated from human- made cellulosic fuels to natural vegetative fuels
Year: 2022
Background: In wildland–urban interface (WUI) fires, particulates from the combustion of both natural vegetative fuels and engineered cellulosic fuels may have deleterious effects on the environment. Aims: The research was conducted to investigate the morphology of the particulate samples generated from the combustion of oriented strand board (OSB). Findings were compared to the particulate samples collected from the combustion of noble-fir branches. Methods: The exposure conditions were varied to induce either smouldering combustion or flaming combustion of the specimens. Particulate samples…
Publication Type: Journal Article
Cognition of feedback loops in a fire-prone social-ecological system
Year: 2022
Increasing wildfire severity highlights the need for large-scale shifts in management of fire-prone landscapes. While prior research has focused on cognitive biases, social norms, and institutional disincentives that limit reform, such factors are best understood as components of feedback loops that operate within complex adaptive systems. We evaluated the prominence and function of feedback loops embedded in cognitive maps—beliefs about patterns of causal relationships that drive system dynamics—elicited from a diverse cross-section of stakeholders in a fire-prone region in the U.S. West. We…
Publication Type: Journal Article
Comparing smoke emissions and impacts under alternative forest management regimes
Year: 2022
Smoke from wildfires has become a growing public health issue around the world but especially in western North America and California. At the same time, managers and scientists recommend thinning and intentional use of wildland fires to restore forest health and reduce smoke from poorly controlled wildfires. Because of the changing climate and management paradigms, the evaluation of smoke impacts needs to shift evaluations from the scale of individual fire events to long-term fire regimes and regional impacts under different management strategies. To confront this challenge, we integrated…
Publication Type: Journal Article
Lifestyle and environmental factors may induce airway and systemic inflammation in firefighters
Year: 2022
Health status depends on multiple genetic and non-genetic factors. Nonheritable factors (such as lifestyle and environmental factors) have stronger impact on immune responses than genetic factors. Firefighters work is associated with exposure to air pollution and heat stress, as well as: extreme physical effort, mental stress, or a changed circadian rhythm, among others. All these factors can contribute to both, short-term and long-term impairment of the physical and mental health of firefighters. Increased levels of some inflammatory markers, such as pro-inflammatory cytokines or C-reactive…
Publication Type: Journal Article