Research Database
Displaying 41 - 60 of 65
Developing an online tool for identifying at-risk populations to wildfire smoke hazards
Year: 2018
Wildfire episodes pose a significant public health threat in the United States. Adverse health impacts associated with wildfires occur near the burn area as well as in places far downwind due to wildfire smoke exposures. Health effects associated with exposure to particulate matter arising from wildfires can range from mild eye and respiratory tract irritation to more serious outcomes such as asthma exacerbation, bronchitis, and decreased lung function. Real-time operational forecasts of wildfire smoke concentrations are available but they are not readily integrated with information on…
Publication Type: Journal Article
It takes a few to tango: changing climate and fire regimes can cause regeneration failure of two subalpine conifers
Year: 2018
Environmental change is accelerating in the 21st century, but how multiple drivers may interact to alter forest resilience remains uncertain. In forests affected by large high-severity disturbances, tree regeneration is a resilience linchpin that shapes successional trajectories for decades. We modeled stands of two widespread western U.S. conifers, Douglas-fir (Pseudotsuga menziesii var. glauca), and lodgepole pine (Pinus contorta var. latifolia), in Yellowstone National Park (Wyoming, USA) to ask (1) What combinations of distance to seed source, fire return interval, and warming-drying…
Publication Type: Journal Article
Estimating post-fire debris-flow hazards prior to wildfire using a statistical analysis of historical distributions of fire severity from remote sensing data
Year: 2018
Following wildfire, mountainous areas of the western United States are susceptible to debris flow during intense rainfall. Convective storms that can generate debris flows in recently burned areas may occur during or immediately after the wildfire, leaving insufficient time for development and implementation of risk mitigation strategies. We present a method for estimating post-fire debris-flow hazards before wildfire using historical data to define the range of potential fire severities for a given location based on the statistical distribution of severity metrics obtained from remote…
Publication Type: Journal Article
An Evaluation of the Forest Service Hazardous Fuels Treatment Program—Are We Treating Enough to Promote Resiliency or Reduce Hazard?
Year: 2017
The National Cohesive Wildland Fire Management Strategy recognizes that wildfire is a necessary natural process in many ecosystems and strives to reduce conflicts between fire-prone landscapes and people. In an effort to mitigate potential negative wildfire impacts proactively, the Forest Service fuels program reduces wildland fuels. As part of an internal program assessment, we evaluated the extent of fuel treatments and wildfire occurrence within lands managed by the National Forest System (NFS) between 2008 and 2012. We intersected fuel treatments with historic disturbance rates to assess…
Publication Type: Journal Article
Decade-Long Plant Community Responses to Shrubland Fuel Hazard Reduction
Year: 2017
Fuel hazard reduction treatments such as prescribed fire and mastication are widely used to reduce fuel hazard. These treatments help protect people from wildfire, yet may not be mutually beneficial for people and ecosystems in areas adapted to infrequent crown fire. Short-term studies indicate that some fuel hazard reduction treatments can be detrimental to biodiversity and ecosystem function, suggesting that land managers face an acute dilemma between protecting people or ecosystems. However, the long-term ecological trajectories and fuel hazard outcomes of fuel treatments are poorly…
Publication Type: Journal Article
Places where wildfire potential and social vulnerability coincide in the coterminous United States
Year: 2016
The hazards-of-place model posits that vulnerability to environmental hazards depends on both biophysical and social factors. Biophysical factors determine where wildfire potential is elevated, whereas social factors determine where and how people are affected by wildfire. We evaluated place vulnerability to wildfire hazards in the coterminous US. We developed a social vulnerability index using principal component analysis and evaluated it against existing measures of wildfire potential and wildland–urban interface designations. We created maps showing the coincidence of social vulnerability…
Publication Type: Journal Article
Review of broad-scale drought monitoring of forests: Toward an integrated data mining approach
Year: 2016
Efforts to monitor the broad-scale impacts of drought on forests often come up short. Drought is a direct stressor of forests as well as a driver of secondary disturbance agents, making a full accounting of drought impacts challenging. General impacts can be inferred from moisture deficits quantified using precipitation and temperature measurements. However, derived meteorological indices may not meaningfully capture drought impacts because drought responses can differ substantially among species, sites and regions. Meteorology-based approaches also require the characterization of current…
Publication Type: Journal Article
Effects of Drought on Forests and Rangelands in the United States: A Comprehensive Science Synthesis
Year: 2016
This assessment provides input to the reauthorized National Integrated Drought Information System (NIDIS) and the National Climate Assessment (NCA), and it establishes the scientific foundation needed to manage for drought resilience and adaptation. Focal areas include drought characterization; drought impacts on forest processes and disturbances such as insect outbreaks and wildfire; and consequences for forest and rangeland values. Drought can be a severe natural disaster with substantial social and economic consequences. Drought becomes most obvious when large-scale changes are observed;…
Publication Type: Report
Does prescribed fire promote resistance to drought in low elevation forests of the Sierra Nevada, California, USA?
Year: 2016
Prescribed fire is a primary tool used to restore western forests following more than a century of fire exclusion, reducing fire hazard by removing dead and live fuels (small trees and shrubs). It is commonly assumed that the reduced forest density following prescribed fire also reduces competition for resources among the remaining trees, so that the remaining trees are more resistant (more likely to survive) in the face of additional stressors, such as drought. Yet this proposition remains largely untested, so that managers do not have the basic information to evaluate whether prescribed…
Publication Type: Journal Article
Wildfire, climate, and perceptions in Northeast Oregon
Year: 2016
Wildfire poses a rising threat in the western USA, fueled by synergies between historical fire suppression, changing land use, insects and disease, and shifts toward a drier, warmer climate. The rugged landscapes of northeast Oregon, with their historically forest- and resource-based economies, have been one of the areas affected. A 2011 survey found area residents highly concerned about fire and insect threats, but not about climate change. In 2014 we conducted a second survey that, to explore this apparent disconnect, included questions about past and future summertime (fire season)…
Publication Type: Journal Article
Models predict longer, deeper U.S. droughts
Year: 2015
Severe, decades-long "megadroughts" that hit the southwestern and midwestern United States over the past millennium may be just a preview of droughts to come in the next century as a result of climate change, new research suggests. According to a new analysis of 17 state-of-the-art climate models and reconstructions of historical drought based on 1000 years of tree-ring data, the regions are heading into a period of unprecedented dryness even if CO2 emissions are dramatically reduced. Under a "business-as-usual" emission scenario, there's an 80% likelihood that at least one decades-long…
Publication Type: Journal Article
Long-term dead wood changes in a Sierra Nevada mixed conifer forest: habitat and fire hazard implications
Year: 2015
Dead trees play an important role in forests, with snags and coarse woody debris (CWD) used by many bird and mammal species for nesting, resting, or foraging. However, too much dead wood can also contribute to extreme fire behavior. This tension between dead wood as habitat and dead wood as fuel has raised questions about appropriate quantities in fire-dependent forested ecosystems. Three plots installed in mixed conifer forest of the central Sierra Nevada in 1929 illustrate how amounts and sizes of dead wood have changed through time as a result of logging and fire exclusion. Diameter of…
Publication Type: Journal Article
Put the wet stuff on the hot stuff': The legacy and drivers of conflict surrounding wildfire suppression
Year: 2015
Existing research demonstrates that wildfire events can lead to conflict among local residents and outside professionals involved in wildfire management or suppression. What has been missing in thewildfire literature is a more explicit understanding of the social dynamics that influence such conflict in rural or agricultural communities and their long-term legacy for future wildfire management. Authorsconducted interviews with local residents of a southeastern Washington community in 2012 to better understand conflict surrounding management of the 2006 Columbia Complex Fire. We utilize…
Publication Type: Journal Article
Categorizing the social context of the wildland urban interface: Adaptive capacity for wildfire and community "archetypes"
Year: 2015
Understanding the local context that shapes collective response to wildfire risk continues to be a challenge for scientists and policymakers. This study utilizes and expands on a conceptual approach for understanding adaptive capacity to wildfire in a comparison of 18 past case studies. The intent is to determine whether comparison of local social context and community characteristics across cases can identify community "archetypes" that approach wildfire planning and mitigation in consistently different ways. Identification of community archetypes serves as a potential strategy for…
Publication Type: Journal Article
Beyond reducing fire hazard: fuel treatment impacts on overstory tree survival
Year: 2014
Fuel treatment implementation in dry forest types throughout the western UnitedStates is likely to increase in pace and scale in response to increasing incidence of large wildfires.While it is clear that properly implemented fuel treatments are effective at reducing hazardousfire potential, there are ancillary ecological effects that can impact forest resilience eitherpositively or negatively depending on the specific elements examined, as well as treatment type,timing, and intensity. In this study, we use overstory tree growth responses, measured sevenyears after the most common fuel…
Publication Type: Journal Article
Correlations between components of the water balance and burned area reveal insights for predicting forest fire area in the southwest United States
Year: 2014
We related measurements of annual burned area in the southwest United States during 1984–2013 to records of climate variability. Within forests, annual burned area correlated at least as strongly with spring–summer vapour pressure deficit (VPD) as with 14 other drought-related metrics, including more complex metrics that explicitly represent fuel moisture. Particularly strong correlations with VPD arise partly because this term dictates the atmospheric moisture demand. Additionally, VPD responds to moisture supply, which is difficult to measure and model regionally due to complex…
Publication Type: Journal Article
Fire behavior in masticated fuels: A review
Year: 2014
Mastication is an increasingly common fuels treatment that redistributes “ladder” fuels to the forest floor to reduce vertical fuel continuity, crown fire potential, and fireline intensity, but fuel models do not exist for predicting fire behavior in these fuel types. Recent fires burning in masticated fuels have behaved in unexpected and contradictory ways, likely because the shredded, compact fuel created when trees and shrubs are masticated contains irregularly shaped pieces in mixtures quite different from other woody fuels. We review fuels characteristics and fire behavior in masticated…
Publication Type: Journal Article
The relationship of large fire occurrence with drought and fire danger indices in the western USA, 1984-2008: the role of temporal scale
Year: 2013
The relationship between large fire occurrence and drought has important implications for fire prediction under current and future climates. This study’s primary objective was to evaluate correlations between drought and fire-danger-rating indices representing short- and long-term drought, to determine which had the strongest relationships with large fire occurrence at the scale of the western United States during the years 1984–2008. We combined 4–8-km gridded drought and fire-danger-rating indices with information on fires greater than 404.7 ha (1000 acres). To account for differences in…
Publication Type: Journal Article