Research Database
Displaying 161 - 180 of 194
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
Regional projections of the likelihood of very large wildland fires under a changing climate in the contiguous Western United States
Year: 2014
Seasonal changes in the climatic potential for very large wildfires (VLWF ≥ 50,000 ac ~ 20,234 ha) across the western contiguous United States are projected over the 21st century using generalized linear models and downscaled climate projections for two representative concentration pathways (RCPs). Significant (p ≤ 0.05) increases in VLWF probability for climate of the mid-21st century (2031–2060) relative to contemporary climate are found, for both RCP 4.5 and 8.5. The largest differences are in the Eastern Great Basin, Northern Rockies, Pacific Northwest, Rocky Mountains, and Southwest.…
Publication Type: Journal Article
Climate and very large wildland fires in the contiguous western USA
Year: 2014
Very large wildfires can cause significant economic and environmental damage, including destruction of homes, adverse air quality, firefighting costs and even loss of life. We examine how climate is associated with very large wildland fires (VLWFs ≥50 000 acres, or ~20 234 ha) in the western contiguous USA. We used composite records of climate and fire to investigate the spatial and temporal variability of VLWF–climatic relationships. Results showed quantifiable fire weather leading up and up to 3 weeks post VLWF discovery, thus providing predictors of the probability that VLWF occurrence in…
Publication Type: Journal Article
Playing with Fire: How climate change and development patterns are constributing to the soaring costs of western wildfires
Year: 2014
Strong scientific evidence shows that climate change is producing hotter, drier conditions that contribute to larger fires and longer fire seasons in the American West today. The annual number of large wildfires on federally managed lands in the 11 western states has increased by more than 75 percent: from approximately 140 during the period 1980–1989 to 250 in the 2000–2009 period. The western wildfire season has grown from five months on average in the 1970s to seven months today. Moreover, the threat of wildfires is projected to worsen over time as rising temperatures—rising more rapidly…
Publication Type: Report
Relationships between climate and macroscale area burned in the western United States
Year: 2013
Increased wildfire activity (e.g. number of starts, area burned, fire behaviour) across the western United States in recent decades has heightened interest in resolving climate–fire relationships. Macroscale climate–fire relationships were examined in forested and non-forested lands for eight Geographic Area Coordination Centers in the western United States, using area burned derived from the Monitoring Trends in Burn Severity dataset (1984–2010). Fire-specific biophysical variables including fire danger and water balance metrics were considered in addition to standard climate variables of…
Publication Type: Journal Article
Allowing a wildfire to burn: estimating the effect on future suppression costs
Year: 2013
Where a legacy of aggressive wildland fire suppression has left forests in need of fuel reduction, allowing wildland fire to burn may provide fuel treatment benefits, thereby reducing suppression costs from subsequent fires. The least-cost-plus-net-value-change model of wildland fire economics includes benefits of wildfire in a framework for evaluating suppression options. In this study, we estimated one component of that benefit – the expected present value of the reduction in suppression costs for subsequent fires arising from the fuel treatment effect of a current fire. To that end, we…
Publication Type: Journal Article
Wildland Fire management: Are actively managed forests more resilient than passively managed forests?
Year: 2013
Large areas of federal lands in the western states are currently at high risk of severe wildfire and have many insect and disease problems, indicating a significant decline in forest health and resilience. Although research studies have not been done that would measure whether actively managed forests are more resilient to wildfires than passively managed forests, results from studies of hazardous fuels treatment effectiveness and the economic benefits from avoided costs of future wildfire suppression due to fuels treatment can be used to support an affirmative reply to the question. If a…
Publication Type: Report
Modelling conditional burn probability patterns for large wildland fires
Year: 2013
We present a technique for modelling conditional burn probability patterns in two dimensions for large wildland fires. The intended use for the model is strategic program planning when information about future fire weather and event durations is unavailable and estimates of the average probabilistic shape and extent of large fires on a landscape are needed. To model average conditional burn probability patterns, we organised historical fire data from Yellowstone National Park, USA, into a set of grids; one grid per fire. We captured various spatial relationships inherent in the gridded data…
Publication Type: Journal Article
Powered by Oregon - The potential for woody biomass
Year: 2013
As a fuel, wood has been with us since humans tamed fire. So what’s the big deal? Why the renewed interest in wood as a source of energy? If we imagine a way to power Oregon that is less dependent on fossil fuels, that is built instead on renewable and homegrown sources of energy, then woody fuel should be a significant part of the picture. Why do we import oil or propane to heat a rural town, for instance, when abundant, clean-burning fuel is a few miles away? Using local fuel creates jobs and keeps money at home. Many small Oregon towns could use more of both. Is it sustainable? Yes. In…
Publication Type: Report
Atmospheric Interactions with Wildland Fire Behaviour I. Basic Surface Interactions, Vertical Profiles and Synoptic Structures
Year: 2012
This paper is the first of two reviewing scientific literature from 100 years of research addressing interactions between the atmosphere and fire behaviour. These papers consider research on the interactions between the fuels burning at any instant and the atmosphere, and the interactions between the atmosphere and those fuels that will eventually burn in a given fire. This first paper reviews the progression from the surface atmospheric properties of temperature, humidity and wind to horizontal and vertical synoptic structures and ends with vertical atmospheric profiles. (The companion paper…
Publication Type: Journal Article
Proceedings of the 3rd Human Dimensions of Wildland Fire Conference
Year: 2012
This proceedings contains articles, posters, and abstracts of presentations from the third Human Dimensions of Wildland Fire Conference held 17-19 April 2012 in Seattle Washington. The conference covered the social issues at the root of wildland fire management’s most serious challenges. Specific topics included: firefighter and public safety; shared responsibility for Community Wildland Fire Safety, public perception and management of wildland and prescribed fire smoke, social networks and communication in management of fire risk, organizational communication, preparedness to name just a few…
Publication Type: Conference Proceedings
Meta-analysis of avian and small-mammal response to fire severity and fire surrogate treatments in US fire-prone forests
Year: 2012
Management in fire-prone ecosystems relies widely upon application of prescribed fire and/or fire surrogate (e.g., forest thinning) treatments to maintain biodiversity and ecosystem function. Recently, published literature examining wildlife response to fire and fire management has increased rapidly. However, none of this literature has been synthesized quantitatively, precluding assessment of consistent patterns of wildlife response among treatment types. Using meta-analysis, we examined the scientific literature on vertebrate demographic responses to burn severity (low/moderate, high), fire…
Publication Type: Journal Article
Principal short-term findings of the National Fire and Fire Surrogate study
Year: 2012
Principal findings of the National Fire and Fire Surrogate (FFS) study are presented in an annotated bibliography and summarized in tabular form by site, discipline (ecosystem component), treatment type, and major theme. Composed of 12 sites, the FFS is a comprehensive multidisciplinary experiment designed to evaluate the costs and ecological consequences of alternative fuel reduction treatments in seasonally dry forests of the United States. The FFS has a common experimental design across the 12-site network, with each site a fully replicated experiment that compares four treatments:…
Publication Type: Report
The Drivers of Effectiveness of Prescribed Fire Treatment
Year: 2012
Prescribed burning for fuel reduction is a major strategy for reducing the risk from unplanned fire. Although there are theoretical studies suggesting that prescribed fire has a strong negative influence on the subsequent area of unplanned fire (so-called leverage), many empirical studies find a more modest influence. Here, I develop a series of simulations to explore the landscape drivers of leverage. Leverage declines with treatment level in a nonlinear, “decay” relationship, implying diminishing effectiveness. The spatial configuration of the prescribed fire treatment has a major effect:…
Publication Type: Journal Article
A Review of Recent Advances in Risk Analysis for Wildfire Management
Year: 2012
Risk analysis evolved out of the need to make decisions concerning highly stochastic events, and is well suited to analyse the timing, location and potential effects of wildfires. Over the past 10 years, the application of risk analysis to wildland fire management has seen steady growth with new risk-based analytical tools that support a wide range of fire and fuels management planning scales from individual incidents to national, strategic interagency programs. After a brief review of the three components of fire risk – likelihood, intensity and effects – this paper reviews recent advances…
Publication Type: Journal Article
Ecological effects of alternative fuel-reduction treatments: highlights of the National Fire and Fire Surrogate study (FSS)
Year: 2012
The 12-site National Fire and Fire Surrogate study (FFS) was a multivariate experiment that evaluated ecological consequences of alternative fuel-reduction treatments in seasonally dry forests of the US. Each site was a replicated experiment with a common design that compared an un-manipulated control, prescribed fire, mechanical and mechanical + fire treatments. Variables within the vegetation, fuelbed, forest floor and soil, bark beetles, tree diseases and wildlife were measured in 10-ha stands, and ecological response was compared among treatments at the site level, and across sites, to…
Publication Type: Journal Article
Long and Short-Term Effects of Fire on Soil Charcoal of a Conifer Forest in Southwest Oregon
Year: 2012
In 2002, the Biscuit Wildfire burned a portion of the previously established, replicated conifer unthinned and thinned experimental units of the Siskiyou Long-Term Ecosystem Productivity (LTEP) experiment, southwest Oregon. Charcoal C in pre and post-fire O horizon and mineral soil was quantified by physical separation and a peroxide-acid digestion method. The abrupt, short-term fire event caused O horizon charcoal C to increase by a factor of ten to >200 kg C ha−1. The thinned wildfire treatment produced less charcoal C than unthinned wildfire and thinned prescribed fire treatments. The…
Publication Type: Journal Article
The Age of Western Wildfires
Year: 2012
The 2012 wildfire season isn’t over yet, but already this year is shaping up to be the one of the worst on record in the American West. According to the National Interagency Fire Center, with nearly two months still to go in the fire season, the total area already burned this year is 30 percent more than in an average year, and fires have consumed more than 8.6 million acres, an area larger than the state of Maryland. Yet, what defines a “typical” wildfire year in the West is changing. In the past 40 years, rising spring and summer temperatures, along with shrinking winter snowpack, have…
Publication Type: Report
Seasonal variation in surface fuel moisture between unthinned and thinned mixed conifer forest, northern California, USA
Year: 2012
Reducing stand density is often used as a tool for mitigating the risk of high-intensity crown fires. However, concern has been expressed that opening stands might lead to greater drying of surface fuels, contributing to increased fire risk. The objective of this study was to determine whether woody fuel moisture differed between unthinned and thinned mixed-conifer stands. Sections of logs representing the 1000- and 10 000-h fuel sizes were placed at 72 stations within treatment units in the fall (autumn) of 2007. Following snow-melt in 2008, 10-h fuel sticks were added and all fuels were…
Publication Type: Journal Article
Alteration and Recovery of Slash Pile Burn Sites in the Restoration of a Fire-Maintained Ecosystem
Year: 2012
Restoration practices incorporating timber harvest (e.g. to remove undesirable species or reduce tree densities) may generate unmerchantable wood debris that is piled and burned for fuel reduction. Slash pile burns are common in longleaf pine ecosystem restoration that involves hardwood removal before reintroduction of frequent prescribed fire. In this context, long-lasting effects of slash pile burns may complicate restoration outcomes due to unintended alterations to vegetation, soils, and the soil seed bank. In this study, our objectives were to (1) examine alterations to the soil seed…
Publication Type: Journal Article