Research Database
Displaying 41 - 60 of 78
Regional patterns of postwildfire streamflow response in the Western United States: The importance of scale-specific connectivity
Year: 2017
Wildfires can impact streamflow by modifying net precipitation, infiltration, evapotranspiration, snowmelt, and hillslope run-off pathways. Regional differences in fire trends and postwildfire streamflow responses across the conterminous United States have spurred concerns about the impact on streamflow in forests that serve as water resource areas. This is notably the case for the Western United States, where fire activity and burn severity have increased in conjunction with climate change and increased forest density due to human fire suppression. In this review, we discuss the effects of…
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
Return on investment from fuel treatments to reduce severe wildfire and erosion in a watershed investment program in Colorado
Year: 2017
A small but growing number of watershed investment programs in the western United States focus on wildfire risk reduction to municipal water supplies. This paper used return on investment (ROI) analysis to quantify how the amounts and placement of fuel treatment interventions would reduce sediment loading to the Strontia Springs Reservoir in the Upper South Platte River watershed southwest of Denver, Colorado following an extreme fire event. We simulated various extents of fuel mitigation activities under two placement strategies: (a) a strategic treatment prioritization map and (b)…
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
Assessment of wildland fire impacts on watershed annual water yield: Analytical framework and case studies in the United States
Year: 2016
More than 50% of water supplies in the conterminous United States originate on forestland or rangeland, and are potentially under increasing stress as a result of larger and more severe wildfires. Little is known however about the long-term impacts of fire on annual water yield, and the role of climate variability within this context. We here propose a framework for evaluating wildland fire impacts on streamflow that combines double-mass analysis with new methods (change point analysis, climate elasticity modeling, and process-based modeling) to distinguish between multi-year fire and climate…
Publication Type: Journal Article
Managed wildfire effects on forest resilience and water in the Sierra Nevada
Year: 2016
Fire suppression in many dry forest types has left a legacy of dense, homogeneous forests. Such landscapes have high water demands and fuel loads, and when burned can result in catastrophically large fires. These characteristics are undesirable in the face of projected warming and drying in the western US. Alternative forest and fire treatments based on managed wildfire—a regime in which fires are allowed to burn naturally and only suppressed under defined management conditions—offer a potential strategy to ameliorate the effects of fire suppression. Understanding the long-term effects of…
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
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
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
Relations between soil hydraulic properties and burn severity
Year: 2015
Wildfire can affect soil hydraulic properties, often resulting in reduced infiltration. The magnitude of change in infiltration varies depending on the burn severity. Quantitative approaches to link burn severity with changes in infiltration are lacking. This study uses controlled laboratory measurements to determine relations between a remotely sensed burn severity metric (dNBR, change in normalised burn ratio) and soil hydraulic properties (SHPs). SHPs were measured on soil cores collected from an area burned by the 2013 Black Forest fire in Colorado, USA. Six sites with the same soil type…
Publication Type: Journal Article
Western Water Threatened by Wildfire: It's Not Just A Public Lands Issue
Year: 2015
Water is the arid West’s most precious and most vulnerable resource. Western water allows metropolises to bloom in the desert, it fuels America’s largest agricultural economy and it supports a ski industry worth more than $6 billion to state and local economies (Burakowski and Magnusson, 2012). The delivery of clean and abundant water is extremely sensitive to disaster, whether natural or man-made. As years-long drought conditions across the region reinforce, the water quantity and quality in the West is never certain.
Publication Type: Report
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
Source of Sediment Hazards on Steep Slopes
Year: 2014
On steep slopes between 30-45 degrees, loose soil is stored behind plant “dams.” After a fire, > 75% of stored sediment is rapidly released to the channel system by dry ravel (the rolling, bouncing, and sliding of individual particles). The postfire hazard from stored sediment can be calculated at the catchment scale if the size and distribution of vegetation cover are known.
Publication Type: Report
Wildfire and the Future of Water Supply
Year: 2014
In many parts of the world, forests provide high quality water for domestic, agricultural, industrial, and ecological needs, with water supplies in those regions inextricably linked to forest health. Wildfires have the potential to have devastating effects on aquatic ecosystems and community drinking water supply through impacts on water quantity and quality. In recent decades, a combination of fuel load accumulation, climate change, extensive droughts, and increased human presence in forests have resulted in increases in area burned and wildfire severity—a trend predicted to continue. Thus,…
Publication Type: Journal Article
Examining fire-prone forest landscapes as coupled human and natural systems
Year: 2014
Fire-prone landscapes are not well studied as coupled human and natural systems (CHANS) and present many challenges for understanding and promoting adaptive behaviors and institutions. Here, we explore how heterogeneity, feedbacks, and external drivers in this type of natural hazard system can lead to complexity and can limit the development of more adaptive approaches to policy and management. Institutions and social networks can counter these limitations and promote adaptation. We also develop a conceptual model that includes a robust characterization of social subsystems for a fire-prone…
Publication Type: Journal Article
Wildland firefighter safety zones: a review of past science and summary of future needs
Year: 2014
Current wildland firefighter safety zone guidelines are based on studies that assume flat terrain, radiant heating, finite flame width, constant flame temperature and high flame emissivity. Firefighter entrapments and injuries occur across a broad range of vegetation, terrain and atmospheric conditions generally when they are within two flame heights of the fire. Injury is not confined to radiant heating or flat terrain; consequently, convective heating should be considered as a potential heating mode. Current understanding of energy transport in wildland fires is briefly summarised, followed…
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 United States 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 hazardous fire potential, there are ancillary ecological effects that can impact forest resilience either positively 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 seven years after the most common fuel…
Publication Type: Journal Article
Five-year legacy of wildfire and salvage logging impacts on nutrient runoff and aquatic plant, invertebrate, and fish productivity
Year: 2014
Ecohydrological linkages between phosphorus (P) production, stream algae, benthic invertebrate, and fish communities were studied for 4 years after severe wildfire in the Rocky Mountains (Alberta, Canada). Mean concentrations of all forms of P (soluble reactive, total dissolved, particulate, and total) were 2 to 13 times greater in burned and post-fire salvage-logged streams than in unburned streams (p < 0.001). Post-disturbance recovery of P was slow with differences in P-discharge relationships still evident 5 years after the fire (p < 0.001). Coupled P and sediment interactions were…
Publication Type: Journal Article
Catchment-scale stream temperature response to land disturbance by wildfire governed by surface–subsurface energy exchange and atmospheric controls
Year: 2014
In 2003, the Lost Creek wildfire severely burned 21,000 hectares of forest on the eastern slopes of the Canadian Rocky Mountains. Seven headwater catchments with varying levels of disturbance (burned, post-fire salvage logged, and unburned) were instrumented as part of the Southern Rockies Watershed Project to measure streamflow, stream temperature, and meteorological conditions. From 2004 to 2010 mean annual stream temperature (Ts) was elevated 0.8–2.1 [1]C in the burned and post-fire salvage logged streams compared to the unburned streams. Mean daily maximum Ts was 1.0–3.0 [1]C warmer and…
Publication Type: Journal Article