Research Database
Displaying 161 - 180 of 217
Fire severity in southwestern Colorado unaffected by spruce beetle outbreak
Year: 2015
Recent large and severe outbreaks of native bark beetles have raised concern among the general public and land managers about potential for amplified fire activity in western North America. To date, the majority of studies examining bark beetle outbreaks and subsequent fire severity in the U.S. Rocky Mountains have focused on outbreaks of mountain pine beetle (MPB, Dendroctonus ponderosae) in lodgepole pine (Pinus contorta) forests, but few studies, particularly field studies, have addressed the effects of the severity of spruce beetle (Dendroctonus rufipennis Kirby) infestation on subsequent…
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
Fire severity and tree regeneration following bark beetle outbreaks: the role of outbreak stage and burning conditions
Year: 2014
The degree to which recent bark beetle (Dendroctonus ponderosae) outbreaks may influence fire severity and postfire tree regeneration is of heightened interest to resource managers throughout western North America, but empirical data on actual fire effects are lacking. Outcomes may depend on burning conditions (i.e., weather during fire), outbreak severity, or intervals between outbreaks and subsequent fire. We studied recent fires that burned through green-attack/red-stage (outbreaks <3 years before fire) and gray-stage (outbreaks 3–15 years before fire) subalpine forests dominated by…
Publication Type: Journal Article
Climate, fire size, and biophysical setting control fire severity and spatial pattern in the northern Cascade Range, USA
Year: 2014
Warmer and drier climate over the past few decades has brought larger fire sizes and increased annual area burned in forested ecosystems of western North America, and continued increases in annual area burned are expected due to climate change. As warming continues, fires may also increase in severity and produce larger contiguous patches of severely burned areas. We used remotely sensed burn-severity data from 125 fires in the northern Cascade Range of Washington, USA, to explore relationships between fire size, severity, and the spatial pattern of severity. We examined relationships between…
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
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
Fuel treatment prescriptions alter spatial patterns of fire severity around the wildland-urban interface during the Wallow Fire, Arizona, USA
Year: 2014
Fuel reduction treatments are implemented in the forest surrounding the wildland–urban interface (WUI) to provide defensible space and safe opportunity for the protection of homes during a wildfire. The 2011 Wallow Fire in Arizona USA burned through recently implemented fuel treatments in the wildland surrounding residential communities in the WUI, and those fuel treatments have been credited with providing firefighter opportunities to protect residences during the Wallow Fire and thereby preventing the loss of homes that otherwise would have been burned. To characterize the spatial pattern…
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
Clearcutting and high severity wildfire have comparable effects on growth of direct-seeded interior Douglas-fir
Year: 2014
The degree to which harvesting can achieve comparable beneficial effects to wildfire on seedling establishment is a key factor in understanding regeneration dynamics in dry interior forest ecosystems. We compared the capacity of harvesting versus wildfire to support establishment of directly-seeded interior Douglas-fir over a three-year period in the interior Douglas-fir biogeoclimatic zone of British Columbia. The mixed-severity McLure Fire of August 2003 affected over 26,000 hectares in the central British Columbia, Canada. Within the fire-affected area, we assessed growth performance in…
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
Previous Fires Moderate Burn Severity of Subsequent Wildland Fires in Two Large Western US Wilderness Areas
Year: 2014
Wildland fire is an important natural process in many ecosystems. However, fire exclusion has reduced frequency of fire and area burned in many dry forest types, which may affect vegetation structure and composition, and potential fire behavior. In forests of the western U.S., these effects pose a challenge for fire and land managers who seek to restore the ecological process of fire to ecosystems. Recent research suggests that landscapes with unaltered fire regimes are more ‘‘self-regulating’’ than those that have experienced fire-regime shifts; in self-regulating systems, fire size and…
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
Landscape restoration of a forest with a historically mixed-severity fire regime: What was the historical landscape pattern of forest and openings?
Year: 2014
Forest management of dry forests in the western US that historically experienced mixed-severity fire regimes is increasingly focused on landscape-scale restoration. However, this restoration effort is constrained by historic range of variation (HRV) reference conditions that lack information concerning the spatial configuration of these forests at intermediate scales (approximately 0.01–100 ha). I used reconstruction methods to map historical (1860) pattern of ponderosa pine-Douglas-fir forests along twenty 1 km long transects on Colorado’s Front Range and compared pre-settlement opening and…
Publication Type: Journal Article
Briefing: Climate and Wildfire in Western U.S. Forests
Year: 2014
Wildfire in western U.S. federally managed forests has increased substantially in recent decades, with large (>1000 acre) fires in the decade through 2012 over five times as frequent (450 percent increase) and burned area over ten times as great (930 percent increase) as the 1970s and early 1980s. These changes are closely linked to increased temperatures and a greater frequency and intensity of drought. Projected additional future warming implies that wildfire activity may continue to increase in western forests. However, the interaction of changes in climate, fire and other disturbances…
Publication Type: Conference Proceedings
Severity of an uncharacteristically large wildfire, the Rim Fire, in forests with relatively restored frequent fire regimes
Year: 2014
The 2013 Rim Fire, originating on Forest Service land, burned into old-growth forests within Yosemite National Park with relatively restored frequent-fire regimes (¡Ý2 predominantly low and moderate severity burns within the last 35 years). Forest structure and fuels data were collected in the field 3-4 years before the fire, providing a rare chance to use pre-existing plot data to analyze fire effects. We used regression tree and random forests analysis to examine the influence of forest structure, fuel, fire history, topographic and weather conditions on observed fire severity in the Rim…
Publication Type: Journal Article
Fuel treatments and landform modify landscape patterns of burn severity in an extreme fire event
Year: 2014
Under a rapidly warming climate, a critical management issue in semiarid forests of western North America is how to increase forest resilience to wildfire. We evaluated relationships between fuel reduction treatments and burn severity in the 2006 Tripod Complex fires, which burned over 70 000 ha of mixed-conifer forests in the North Cascades range of Washington State and involved 387 past harvest and fuel treatment units. A secondary objective was to investigate other drivers of burn severity including landform, weather, vegetation characteristics, and a recent mountain pine beetle outbreak.…
Publication Type: Journal Article
Recent mountain pine beetle outbreaks, wildfire severity, and postfire tree regeneration in the US Northern Rockies
Year: 2014
Widespread tree mortality caused by outbreaks of native bark beetles (Circulionidae: Scolytinae) in recent decades has raised concern among scientists and forest managers about whether beetle outbreaks fuel more ecologically severe forest fires and impair postfire resilience. To investigate this question, we collected extensive field data following multiple fires that burned subalpine forests in 2011 throughout the Northern Rocky Mountains across a spectrum of prefire beetle outbreak severity, primarily from mountain pine beetle (Dendroctonus ponderosae). We found that recent (2001–2010)…
Publication Type: Journal Article
Pre-wildfire fuel reduction treatments result in more resilient forest structure a decade after wildfire
Year: 2013
Increasing size and severity of wildfires have led to an interest in the effectiveness of forest fuels treatments on reducing fire severity and post-wildfire fuels. Our objective was to contrast stand structure and surface fuel loadings on treated and untreated sites within the 2002 Rodeo–Chediski Fire area. Data from 140 plots on seven paired treated–untreated sites indicated that pre-wildfire treatments reduced fire severity compared with untreated sites. In 2011, coarse woody debris loading (woody material >7.62 cm in diameter) was 257% higher and fine woody debris (woody material <7…
Publication Type: Journal Article
ArcFuels10 System Overview
Year: 2013
Fire behavior modeling and geospatial analyses can provide tremendous insight for land managers as they grapple with the complex problems frequently encountered in wildfire risk assessments and fire and fuels management planning. Fuel management often is a particularly complicated process in which the benefits and potential impacts of fuel treatments need to be demonstrated in the context of land management goals and public expectations. The fuel treatment planning process is complicated by the lack of data assimilation among fire behavior models and weak linkages to geographic information…
Publication Type: Report