Research Database
Displaying 161 - 180 of 198
Fire regimes of quaking aspen in the Mountain West
Year: 2013
Quaking aspen, the most widespread tree species in North America, reproduces primarily by resprouting from roots. In some stands, mortality from fire encourages sprouting and prevents conifers from eventually replacing aspen. In other areas, aspen can form stable communities that do not require fire to regenerate or persist. USGS fire ecologist Doug Shinneman and colleagues reviewed literature about aspen populations and fire, summarized research findings, and suggested a classification system for aspen across the western mountainous United States. The scientists proposed five aspen “fire…
Publication Type: Journal Article
Fire-mediated pathways of stand development in Douglas-fir/ western hemlock forests of the Pacific Northwest, USA
Year: 2013
Forests dominated by Douglas-fir and western hemlock in the Pacific Northwest of the United States have strongly influenced concepts and policy concerning old-growth forest conservation. Despite the attention to their old-growth characteristics, a tendency remains to view their disturbance ecology in relatively simple terms, emphasizing infrequent, stand-replacing (SR) fire and an associated linear pathway toward development of those old-growth characteristics. This study uses forest stand- and age-structure data from 124 stands in the central western Cascades of Oregon to construct a…
Publication Type: Journal Article
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
Trial by fire: Community Wildfire Protection Plans put to the test
Year: 2013
Research has found that community wildfire protection planning can make significant contributions to wildfire mitigation and preparedness, but can the planning process and resulting Community Wildfire Protection Plans make a difference to wildfire response and recovery? In case studies conducted in four USA communities with Community Wildfire Protection Plans in place when wildfires occurred, we saw a range of Community Wildfire Protection Plan projects designed to change the path and intensity of the wildfires. In most of our communities, the Community Wildfire Protection Plan and planning…
Publication Type: Journal Article
Fuel Treatments and Fire Severity: A Meta-Analysis
Year: 2013
We employed meta-analysis and information theory to synthesize findings reported in the literature on the effects of fuel treatments on subsequent fire intensity and severity. Data were compiled from 19 publications that reported observed fire responses from 62 treated versus untreated contrasts. Effect sizes varied widely and the most informative grouping of studies distinguished three vegetation types and three types of fuel treatment. The resultant meta-analytic model is highly significant (p<0.001) and explains 78% of the variability in reported observations of fuel treatment…
Publication Type: Report
Restoring and Managing Mixed Conifer Forests in the PNW
Year: 2013
Many collaborative groups working across the eastside of Oregon and Washington have developed good working agreements on treatments appropriate for ponderosa pine forest types. These groups are actively supporting and helping to develop projects that will meet ecological objectives for dry forests while generating jobs and economic activity in local communities. Currently, there is less agreement on how to approach restoration and management of mixed-conifer forests, in large part because there does not appear to be a comparable scientific consensus as that which exists for ponderosa pine…
Publication Type: Conference Proceedings
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
Building community-agency trust in fire affected communities in Australia and the United States
Year: 2013
As a result of the increasing environmental and social costs of wildfire, fire management agencies face ever-growing complexity in their management decisions and interactions with the public. The success of these interactions with community members may be facilitated through building community–agency trust in the process of providing public input opportunities and community engagement and education activities. Without trust, the public may become frustrated in their interactions with the agency and withhold support for management decisions. This study takes a comparative case approach using…
Publication Type: Journal Article
Managing Forests and Fire in Changing Climates
Year: 2013
With projected climate change, we expect to face much more forest fi re in the coming decades. Policymakers are challenged not to categorize all fires as destructive to ecosystems simply because they have long flame lengths and kill most of the trees within the fire boundary. Ecological context matters: In some ecosystems, high-severity regimes are appropriate, but climate change may modify these fire regimes and ecosystems as well. Some undesirable impacts may be avoided or reduced through global strategies, as well as distinct strategies based on a forest’s historical fire regime.
Publication Type: Report
Soil heating during burning of forest slash piles and wood piles
Year: 2013
Pile burning of conifer slash is a common fuel reduction practice in forests of the western United States that has a direct, yet poorly quantified effect on soil heating. To address this knowledge gap, we measured the heat pulse beneath hand-built piles ranging widely in fuel composition and pile size in sandy-textured soils of the Lake Tahoe Basin. The soil heat pulse depended primarily on fuel composition, not on pile size. Burn piles dominated by large wood produced extreme temperatures in soil profile, with lethal heating lasting up to 3 days. In contrast, the heat pulse was moderate…
Publication Type: Journal Article
Restoration of dry forests in eastern Oregon: A field guide
Year: 2013
Dry Forest landscapes dominated by pine and mixed-conifer forests composed of ponderosa pine and associated coniferous species, such as Douglas-fir and white or grand fir, are extensive in western North America, including the Pacific Northwest (Franklin and Dyrness, 1988). These forests typically occupy landscapes that are moisture limited and historically experienced disturbance regimes that included frequent wildfire. On many sites fires were predominantly low severity but mixed-severity and, occasionally, even high-severity wildfire occurred, the latter primarily in areas at higher…
Publication Type: Report
Estimation of Wildfire Size and Risk Changes Due to Fuels Treatments
Year: 2012
Human land use practices, altered climates, and shifting forest and fire management policies have increased the frequency of large wildfires several-fold. Mitigation of potential fire behaviour and fire severity have increasingly been attempted through pre-fire alteration of wildland fuels using mechanical treatments and prescribed fires. Despite annual treatment of more than a million hectares of land, quantitative assessments of the effectiveness of existing fuel at reducing the size of actual wildfires or how they might alter the risk of burning across landscapes are currently lacking.…
Publication Type: Journal Article
Temporal dynamics and decay of coarse wood in early seral habitats of dry-mixed conifer forests in Oregon’s Eastern Cascades
Year: 2012
Early seral forest habitats are increasingly valued for the unique structural resources they provide in many western US forests. Coarse woody detritus (CWD) are a significant feature of this developmental stage and are highly dynamic, suggesting these environments exhibit temporally diverse structural conditions prior to forest canopy closure. In dry-mixed conifer forests, snags are hypothesized to decay slower than logs making long-term dynamics in these forests dependent on snag fall, breakage and the decay rates of both standing and surface CWD. We estimated snag fall and breakage rates…
Publication Type: Journal Article
The Importance of Framing for Communicating Risk and Managing Forest Health
Year: 2012
Despite the importance of effective communication about forest and fuel management, little is known about how best to frame information to facilitate public understanding and increase support. The results presented here indicate that framing a fuel management plan as necessary to restore "lost" forest health (as opposed to maintaining or improving forest health) will increase the willingness of individuals to support options that pose some likelihood of failure (i.e. risk). Strategic framing of communication for public audiences is necessary because of the common biases in judgment that can…
Publication Type: Journal Article
The Effects of Forest Fuel-Reduction Treatments in the United States
Year: 2012
The current conditions of many seasonally dry forests in the western and southern United States, especially those that once experienced low- to moderate-intensity fire regimes, leave them uncharacteristically susceptible to high-severity wildfire. Both prescribed fire and its mechanical surrogates are generally successful in meeting short-term fuel-reduction objectives such that treated stands are more resilient to high-intensity wildfire. Most available evidence suggests that these objectives are typically accomplished with few unintended consequences, since most ecosystem components (…
Publication Type: Journal Article
Fuel Treatment Effectiveness in California Yellow Pine and Mixed Conifer Forests
Year: 2012
We assessed the effectiveness of forest fuel thinning projects that explicitly removed surface and ladder fuels (all but one were combined mechanical and prescribed fire/pile burn prescriptions) in reducing fire severity and tree mortality in 12 forest fires that burned in eastern and southern California between 2005 and 2011. All treatments and fires occurred in yellow pine or mixed conifer forests, in a variety of landscape conditions. Most fires burned under warm, dry conditions, with moderate to high winds. With few exceptions, fire severity measures (bole char height, scorch and torch…
Publication Type: Journal Article
Wildfire severity mediates fluxes of plant material and terrestrial invertebrates to mountain streams
Year: 2012
Wildfire effects upon riparian plant community structure, composition, and distribution may strongly influence the dynamic relationships between riparian vegetation and stream ecosystems. However, few studies have examined the influence of fire on these processes. To that end, we compared the quantity and composition of allochthonous inputs of plant material and terrestrial invertebrates among stream tributaries characterized by various degrees of burn severity 5 years post-fire in the Frank Church Wilderness of central Idaho, USA. The magnitude of inputs of coniferous leaf litter to unburned…
Publication Type: Journal Article
Surface fuel treatments in young, regenerating stands affect wildfire severity in a mixed conifer forest, eastside Cascade Range, Washington, USA
Year: 2012
Previous studies have debated the flammability of young regenerating stands, especially those in a matrix of mature forest, and no consensus has emerged as to whether young stands are inherently prone to high severity wildfire. This topic has recently been addressed using spatial imagery, and weak inferences were made given the scale mismatch between the coarse resolution of spatial imagery and the fine resolution of mechanisms driving fire severity. We collected empirical stand and fire-severity data from 44 regenerating stands that are interspersed in mature, mid-elevation forests in the…
Publication Type: Journal Article
Fuel Variability Following Wildfire in Forests with Mixed Severity Fire Regimes, Cascade Range, USA
Year: 2012
Fire severity influences post-burn structure and composition of a forest and the potential for a future fire to burn through the area. The effects of fire on forests with mixed severity fire regimes are difficult to predict and interpret because the quantity, structure, and composition of forest fuels vary considerably. This study examines the relationship between fire severity and post-burn fuel characteristics in forests with mixed severity fire regimes. We sampled live and dead canopy and…
Publication Type: Journal Article
Communication of the Role of Natural Variability in Future North American Climate
Year: 2012
As climate models improve, decision-makers' expectations for accurate climate predictions are growing. Natural climate variability, however, poses inherent limits to climate predictability and the related goal of adaptation guidance in many places, as illustrated here for North America. Other locations with low natural variability show a more predictable future in which anthropogenic forcing can be more readily identified, even on small scales. We call for a more focused dialogue between scientists, policymakers and the public to improve communication and avoid raising expectations for…
Publication Type: Journal Article