Research Database
Displaying 121 - 140 of 186
Tamm Review: Shifting global fire regimes: Lessons from reburns and research needs
Year: 2017
Across the globe, rising temperatures and altered precipitation patterns have caused persistent regional droughts, lengthened fire seasons, and increased the number of weather-driven extreme fire events. Because wildfires currently impact an increasing proportion of the total area burned, land managers need to better understand reburns – in which previously burned areas can modify the patterns and severity of subsequent fires. For example, knowing how long past fire boundaries can function as barriers to fire spread may empower decision-makers to manage some wildfires as large-scale fuel…
Publication Type: Journal Article
NFPA’s Wildland/Urban Interface: Fire Department Wildfire Preparedness and Readiness Capabilities – Final Report
Year: 2017
The increasing frequency and intensity of wildland and wildland-urban interface (WUI) fires have become a significant concern in many parts of the United States and around the world. To address and manage this WUI fire risk, local fire departments around the country have begun to acquire the appropriate equipment and offer more training in wildfire response and suppression. There is also growing recognition of the importance of wildfire mitigation and public outreach about community risk reduction. Using survey and interview data from 46 senior officers from local fire departments around the…
decision making, management, wildland fire, Wildland-urban interface (WUI), fire suppression, adaptation
Publication Type: Report
Returning Fire to the Land—Celebrating Traditional Knowledge and Fire
Year: 2017
North American tribes have traditional knowledge about fire effects on ecosystems, habitats, and resources. For millennia, tribes have used fire to promote valued resources. Sharing our collective understanding of fire, derived from traditional and western knowledge systems, can benefit landscapes and people. We organized two workshops to investigate how traditional and western knowledge can be used to enhance wildland fire and fuels management and research. We engaged tribal members, managers, and researchers to formulate solutions regarding the main topics identified as important to tribal…
Publication Type: Journal Article
Long-Term Effects of Burn Season and Frequency on Ponderosa Pine Forest Fuels and Seedlings
Year: 2017
Prescribed fire is widely applied in western US forests to limit future fire severity by reducing tree density, fuels, and excessive seedlings. Repeated prescribed burning attempts to simulate historical fire regimes in frequent-fire forests, yet there is limited long-term information regarding optimal burn season and frequency. In addition, burns are operationally feasible only in the spring and late fall, largely outside the historical wildfire season. This study quantifies the effect of seasonal reburns on woody surface fuels, forest floor fuels, and understory tree regeneration abundance…
Publication Type: Journal Article
A Century of Wildland Fire Research - Contributions to Long-term Approaches for Wildland Fire Management: Proceedings of a Workshop
Year: 2017
Although ecosystems, humans, and fire have coexisted for millennia, changes in geology, ecology, hydrology, and climate as well as sociocultural, regulatory, and economic factors have converged to make wildland fire management exceptionally challenging for U.S. federal, state, and local authorities. Given the mounting, unsustainable costs and difficulty translating existing wildland fire science into policy, the National Academies of Sciences, Engineering, and Medicine organized a 1-day workshop to focus on how a century of wildland fire research can contribute to improving wildland fire…
Publication Type: Report
Fires following Bark Beetles: Factors Controlling Severity and Disturbance Interactions in Ponderosa Pine
Year: 2017
Previous studies have suggested that bark beetles and fires can be interacting disturbances, whereby bark beetle–caused tree mortality can alter the risk and severity of subsequent wildland fires. However, there remains considerable uncertainty around the type and magnitude of the interaction between fires following bark beetle attacks, especially in drier forest types such as those dominated by ponderosa pine (Pinus ponderosa Lawson & C. Lawson). We used a full factorial design across a range of factors thought to control bark beetle−fire interactions, including the temporal phase of the…
Publication Type: Journal Article
A review of challenges to determining and demonstrating efficiency of large fire management
Year: 2017
Characterising the impacts of wildland fire and fire suppression is critical information for fire management decision-making. Here, we focus on decisions related to the rare larger and longer-duration fire events, where the scope and scale of decision-making can be far broader than initial response efforts, and where determining and demonstrating efficiency of strategies and actions can be particularly troublesome. We organise our review around key decision factors such as context, complexity, alternatives, consequences and uncertainty, and for illustration contrast fire management in…
Publication Type: Journal Article
Historical Fire–Climate Relationships in Contrasting Interior Pacific Northwest Forest Types
Year: 2017
Describing the climate influences on historical wildland fire will aid managers in planning for future change. This study uses existing historical climate reconstructions and a new fire history from the southern Blue Mountains in eastern Oregon, USA, to: 1) characterize historical fire-climate relationships, and 2) determine if climatic influences on fire differed among dry sites dominated by ponderosa pine (Pinus ponderosa Dougl. ex Laws) and more productive sites with significant older fire intolerant grand fir (Abies grandis [Dougl.] Lindl.) structure.
Publication Type: Journal Article
Efficacy of resource objective wildfires for restoration of ponderosa pine (Pinus ponderosa) forests in northern Arizona
Year: 2017
Current conditions in dry forests of the western United State have given rise to policy mandates for accelerated ecological restoration on U.S. National Forest System and other public lands. In southwestern ponderosa pine (Pinus ponderosa Laws.) forests, mechanized tree thinning and prescribed fire are common restoration treatments but are not acceptable for all sites. Currently there is much interest in managing naturally ignited fires to accomplish restoration objectives but few studies have systematically examined the efficacy of such “resource objective” wildfires for restoring historical…
Publication Type: Journal Article
Restoring forest structure and process stabilizes forest carbon in wildfire-prone southwestern ponderosa pine forests
Year: 2016
Changing climate and a legacy of fire-exclusion have increased the probability of high-severity wildfire, leading to an increased risk of forest carbon loss in ponderosa pine forests in the southwestern USA. Efforts to reduce high-severity fire risk through forest thinning and prescribed burning require both the removal and emission of carbon from these forests, and any potential carbon benefits from treatment may depend on the occurrence of wildfire. We sought to determine how forest treatments alter the effects of stochastic wildfire events on the forest carbon balance. We modeled three…
Publication Type: Journal Article
Review of the health effects of wildland fire smoke on wildland firefighters and the public
Year: 2016
Each year, the general public and wildland firefighters in the US are exposed to smoke from wildland fires. As part of an effort to characterize health risks of breathing this smoke, a review of the literature was conducted using five major databases, including PubMed and MEDLINE Web of Knowledge, to identify smoke components that present the highest hazard potential, the mechanisms of toxicity, review epidemiological studies for health effects and identify the current gap in knowledge on the health impacts of wildland fire smoke exposure. Respiratory events measured in time series studies as…
Publication Type: Journal Article
Forest fire policy: change conventional thinking of smoke management to prioritize long-term air quality and public health
Year: 2016
Wildland fire smoke is inevitable. Size and intensity of wildland fires are increasing in the western USA. Smoke-free skies and public exposure to wildland fire smoke have effectively been postponed through suppression. The historic policy of suppression has systematically both instilled a public expectation of a smoke-free environment and deferred emissions through increased forest fuel loads that will lead to an eventual large spontaneous release. High intensity fire smoke is impacting a larger area including high density urban areas. Policy change has largely attempted to provide the…
Publication Type: Journal Article
Weather, fuels, and topography impede wildland fire spread in western US landscapes
Year: 2016
As wildland fire activity continues to surge across the western US, it is increasingly important that we understand and quantify the environmental drivers of fire and how they vary across ecosystems. At daily to annual timescales, weather, fuels, and topography are known to influence characteristics such as area burned and fire severity. An understudied facet, however, concerns how these factors inhibit fire spread and thereby contribute to the formation of fire boundaries. We evaluated how weather, fuels, and topography impeded fire spread in four large study areas in the western US, three…
Publication Type: Journal Article
Risk management: Core principles and practices, and their relevance to wildland fire
Year: 2016
The Forest Service, U.S. Department of Agriculture faces a future of increasing complexity and risk, pressing financial issues, and the inescapable possibility of loss of human life. These issues are perhaps most acute for wildland fire management, the highest risk activity in which the Forest Service engages. Risk management (RM) has long been put forth as an appropriate approach for addressing fire, and agency-wide adoption of RM principles and practices will be critical to bring about necessary change and improve future decisions. To facilitate more comprehensive adoption of formal RM…
Publication Type: Report
Recovering lost ground: Effects of soil burn intensity on nutrients and ectomycorrhiza communities of ponderosa pine seedlings
Year: 2016
Fuel accumulation and climate shifts are predicted to increase the frequency of high-severity fires in ponderosa pine (Pinus ponderosa) forests of central Oregon. The combustion of fuels containing large downed wood can result in intense soil heating, alteration of soil properties, and mortality of microbes. Previous studies show ectomycorrhizal fungi (EMF) improve ponderosa seedling establishment after fire but did not compare EMF communities at different levels of soil burn intensity in a field setting. For this study, soil burn intensity effects on nutrients and EMF communities were…
Publication Type: Journal Article
Megafires: an emerging threat to old-forest species
Year: 2016
Increasingly frequent “megafires” in North America's dry forests have prompted proposals to restore historical fire regimes and ecosystem resilience. Restoration efforts that reduce tree densities (eg via logging) could have collateral impacts on declining old-forest species, but whether these risks outweigh the potential effects of large, severe fires remains uncertain. We demonstrate the effects of a 2014 California megafire on an iconic old-forest species, the spotted owl (Strix occidentalis). The probability of owl site extirpation was seven times higher after the fire (0.88) than before…
Publication Type: Journal Article
Progress in wilderness fire science: Embracing complexity
Year: 2016
Wilderness has played an invaluable role in the development of wildland fire science. Since Agee’s review of the subject 15 years ago, tremendous progress has been made in the development of models and data, in understanding the complexity of wildland fire as a landscape process, and in appreciating the social factors that influence the use of wilderness fire. Regardless of all we have learned, though, the reality is that fire remains an extraordinarily complex process with variable effects that create essential heterogeneity in ecosystems. Whereas some may view this variability as a…
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
Did the 2002 Hayman Fire, Colorado, USA, Burn with Uncharacteristic Severity?
Year: 2016
There is considerable interest in evaluating whether recent wildfires in dry conifer forests of western North America are burning with uncharacteristic severity—that is, with a severity outside the historical range of variability. In 2002, the Hayman Fire burned an unlogged 3400 ha dry conifer forest landscape in the Colorado Front Range, USA, that had been the subject of previous fire history and forest age structure research. We opportunistically leveraged pre-existing data from this research, in combination with post-fire aerial imagery, to provide insight into whether the Hayman Fire’s…
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