Research Database
Displaying 221 - 240 of 328
Evaluating Prescribed Fire Effectiveness Using Permanent Monitoring Plot Data: A Case Study
Year: 2016
Since Euro-American settlement, ponderosa pine forests throughout the western United States have shifted from high fire frequency and open canopy savanna forests to infrequent fire and dense, closed canopy forests. Managers at Zion National Park, USA, reintroduced fire to counteract these changes and decrease the potential for high-severity fires. We analyzed existing permanent monitoring plot data collected between 1995 and 2010 to assess achievement of management objectives related to prescribed fire in ponderosa pine forests. Following first entry fire, ponderosa pine (Pinus ponderosa C.…
Publication Type: Journal Article
The impact of aging on laboratory fire behaviour in masticated shrub fuelbeds of California and Oregon, USA
Year: 2016
Mastication of shrubs and small trees to reduce fire hazard has become a widespread management practice, yet many aspects of the fire behaviour of these unique woody fuelbeds remain poorly understood. To examine the effects of fuelbed aging on fire behaviour, we conducted laboratory burns with masticated Arctostaphylos spp. and Ceanothus spp. woody debris that ranged from 2 to 16 years since treatment. Masticated fuels that were 10 years or older burned with 18 to 29% shorter flame heights and 19% lower fireline intensities compared with the younger fuelbeds across three different fuel loads…
Publication Type: Journal Article
Developing and Implementing Climate Change Adaptation Options in Forest Ecosystems: A Case Study in Southwestern Oregon, USA
Year: 2016
Climate change will likely have significant effects on forest ecosystems worldwide. In Mediterranean regions, such as that in southwestern Oregon, USA, changes will likely be driven mainly by wildfire and drought. To minimize the negative effects of climate change, resource managers require tools and information to assess climate change vulnerabilities and to develop and implement adaptation actions. We developed an approach to facilitate development and implementation of climate change adaptation options in forest management. This approach, applied in a southwestern Oregon study region,…
Publication Type: Journal Article
Predicting large wildfires across western North America by modeling seasonal variation in soil water balance
Year: 2016
A lengthening of the fire season, coupled with higher temperatures, increases the probability of fires throughout much of western North America. Although regional variation in the frequency of fires is well established, attempts to predict the occurrence of fire at a spatial resolution <10 km2 have generally been unsuccessful. We hypothesized that predictions of fires might be improved if depletion of soil water reserves were coupled more directly to maximum leaf area index (LAImax) and stomatal behavior. In an earlier publication, we used LAImax and a process-based forest growth model to…
Publication Type: Journal Article
Facilitating knowledge transfer between researchers and wildfire practitioners about trust: An international case study
Year: 2016
The importance of knowledge transfer between researchers, policy makers and practitioners is widely recognized. However, barriers to knowledge transfer can make it difficult for practitioners to apply the results of scientific research. This paper describes a project that addressed barriers to knowledge transfer by involving wildfire management practitioners from three countries in developing a trust planning guide. The guide provides information about trust, factors that influence trust and actions that can be taken to build trust in the context of wildfire management. The researchers…
Publication Type: Journal Article
Assessing the impacts of federal forest planning on wildfire risk-mitigation in the Pacific Northwest, USA
Year: 2016
We analyzed the impact of amenity and biodiversity protection as mandated in national forest plans on the implementation of hazardous fuel reduction treatments aimed at protecting the wildland urban interface (WUI) and restoring fire resilient forests. We used simulation modeling to delineate areas on national forests that can potentially transmit fires to adjacent WUI. We then intersected these areas with national forest planning maps to determine where mechanical treatments are allowed for restoration and fire protection, versus areas where they are prohibited. We found that a large…
Publication Type: Journal Article
Forest fuels and potential fire behaviour 12 years after variable-retention harvest in lodgepole pine
Year: 2016
Variable-retention harvesting in lodgepole pine offers an alternative to conventional, even-aged management. This harvesting technique promotes structural complexity and age-class diversity in residual stands and promotes resilience to disturbance. We examined fuel loads and potential fire behaviour 12 years after two modes of variable-retention harvesting (dispersed and aggregated retention patterns) crossed by post-harvest prescribed fire (burned or unburned) in central Montana. Results characterise 12-year post-treatment fuel loads. We found greater fuel load reduction in treated than…
Publication Type: Journal Article
Available Science Assessment Project: Prescribed Fire and Climate Change in Northwest National Forests
Year: 2016
Climate change is one of the most pressing issues facing natural resource management. The disruptions it is causing require that we change how we consider conservation and resource management in order to ensure the future of habitats, species, and human communities, whether that means adopting new actions or adjusting the ways in which existing actions are implemented. However, practitioners often struggle with how to identify and prioritize specific climate adaptation actions, which are taken to either increase/enhance resilience or decrease vulnerability in a changing climate. Management…
Publication Type: Report
Forest management scenarios in a changing climate: trade-offs between carbon, timber, and old forest
Year: 2016
Balancing economic, ecological, and social values has long been a challenge in the forests of the Pacific Northwest, where conflict over timber harvest and old-growth habitat on public lands has been contentious for the past several decades. The Northwest Forest Plan, adopted two decades ago to guide management on federal lands, is currently being revised as the region searches for a balance between sustainable timber yields and habitat for sensitive species. In addition, climate change imposes a high degree of uncertainty on future forest productivity, sustainability of timber harvest,…
Publication Type: Journal Article
Wilderness in the 21st Century: A Framework for Testing Assumptions about Ecological Intervention in Wilderness Using a Case Study in Fire Ecology in the Rocky Mountains
Year: 2016
Changes in the climate and in key ecological processes are prompting increased debate about ecological restoration and other interventions in wilderness. The prospect of intervention in wilderness raises legal, scientific, and values-based questions about the appropriateness of possible actions. In this article, we focus on the role of science to elucidate the potential need for intervention. We review the meaning of “untrammeled” from the 1964 Wilderness Act to aid our understanding of the legal context for potential interventions in wilderness. We explore the tension between restraint and…
Publication Type: Journal Article
Experimental analysis of fire spread across a two-dimensional ridge under wind conditions
Year: 2015
Results from a laboratory-scale investigation of a fire spreading on the windward face of a triangular-section hill of variable shape with wind perpendicular to the ridgeline are reported. They confirm previous observations that the fire enlarges its lateral spread after reaching the ridgeline, entering the leeward face with a much wider front. Reference fire spread velocities were measured and analysed, putting in evidence the importance of the dynamic effect due to flow velocity and its associated horizontal-axis separation vortex strength without dependence on hill geometry. Similar…
Publication Type: Journal Article
Evaluating crown fire rate of spread predictions from physics-based models
Year: 2015
Modeling the behavior of crown fires is challenging due to the complex set of coupled processes that drive the characteristics of a spreading wildfire and the large range of spatial and temporal scales over which these processes occur. Detailed physics-based modeling approaches such as FIRETEC and the Wildland Urban Interface Fire Dynamics Simulator (WFDS) simulate fire behavior using computational fluid dynamics based methods to numerically solve the three-dimensional, time dependent, model equations that govern, to some approximation, the component physical processes and their interactions…
Publication Type: Journal Article
Local Ecological Knowledge and Fire Management: What Does the Public Understand?
Year: 2015
As fire management agencies seek to implement more flexible fire management strategies, local understanding and support for these strategies become increasingly important. One issue associated with implementing more flexible fire management strategies is educating local populations about fire management and identifying what local populations know or do not know related to fire management. This study used survey data from three 2010 wildland fires to understand how ecological knowledge and education level affected fire management perception and understanding. Results indicated that increased…
Publication Type: Journal Article
A Wildfire-relevant climatology of the convective environment of the United States
Year: 2015
Convective instability can influence the behaviour of large wildfires. Because wildfires modify the temperature and moisture of air in their plumes, instability calculations using ambient conditions may not accurately represent convective potential for some fire plumes. This study used the North American Regional Reanalysis to develop a climatology of the convective environment specifically tied to large fire events. The climatology is based on the period 1979–2009 and includes ambient convective available potential energy (CAPE) as well as values when surface air is warmed by 0.5, 1.0 or 2.0…
Publication Type: Journal Article
The economic benefit of localised, short-term, wildfire-potential information
Year: 2015
Wildfire-potential information products are designed to support decisions for prefire staging of movable wildfire suppression resources across geographic locations. We quantify the economic value of these information products by defining their value as the difference between two cases of expected fire-suppression expenditures: one in which daily information about spatial variation in wildfire-potential is used to move fire suppression resources throughout the season, and the other case in which daily information is not used and fire-suppression resources are staged in their home locations all…
Publication Type: Journal Article
Reform forest fire management
Year: 2015
Globally, wildfire size, severity, and frequency have been increasing, as have related fatalities and taxpayer-funded firefighting costs (1). In most accessible forests, wildfire response prioritizes suppression because fires are easier and cheaper to contain when small (2). In the United States, for example, 98% of wildfires are suppressed before reaching 120 ha in size (3). But the 2% of wildfires that escape containment often burn under extreme weather conditions in fuel-loaded forests and account for 97% of fire-fighting costs and total area burned (3). Changing climate and decades of…
Publication Type: Journal Article
Recovery of small pile burn scars in conifer forests of the Colorado Front Range
Year: 2015
The ecological consequences of slash pile burning are a concern for land managers charged with maintaining forest soil productivity and native plant diversity. Fuel reduction and forest health management projects have created nearly 150,000 slash piles scheduled for burning on US Forest Service land in northern Colorado. The vast majority of these are small piles (<5 m diameter). Similar to larger piles, we found that burning small piles had significant immediate effects on soil nutrients and physical and chemical properties and native plant cover. To evaluate the need to rehabilitate…
Publication Type: Journal Article
Fire and non-native grass invasion interact to suppress tree regeneration in temperate deciduous forests
Year: 2015
While many ecosystems depend on fire to maintain biodiversity, non-native plant invasions can enhance fire intensity, suppressing native species and generating a fire–invasion feedback. These dynamics have been observed in arid and semi-arid ecosystems, but fire–invasion interactions in temperate deciduous forests, where prescribed fires are often used as management tools to enhance native diversity, have rarely been investigated. Here we evaluated the effects of a widespread invasive grass on fire behaviour in eastern deciduous forests in the USA and the potential effects of fire and…
Publication Type: Journal Article
Fuel and vegetation trends after wildfire in treated versus untreated forests
Year: 2015
Increasing size and severity of wildfires have led to increased interest in managing forests for resiliency to future disturbances. Comparing and contrasting treated versus untreated stands through multiple growing seasons postfire provide an opportunity to understand processes driving responses and can guide management decisions regarding resiliency. In treated and untreated forests, we compared fire effects 2‐10 growing seasons following fire on 3 different fires in New Mexico and Arizona. We estimated understory cover, standing crop, fuel loading, and basal area in (1) lop, pile, burn; (2…
Publication Type: Journal Article
Winter grazing can reduce wildfire size, intensity and behaviour in a shrub-grassland
Year: 2015
An increase in mega-fires and wildfires is a global issue that is expected to become worse with climate change. Fuel treatments are often recommended to moderate behaviour and decrease severity of wildfires; however, the extensive nature of rangelands limits the use of many treatments. Dormant-season grazing has been suggested as a rangeland fuel treatment, but its effects on fire characteristics are generally unknown. We investigated the influence of dormant-season (winter) grazing by cattle (Bos taurus) on fuel characteristics, fire behaviour and area burned in Wyoming big sagebrush (…
Publication Type: Journal Article