Research Database
Displaying 81 - 98 of 98
Predicting Dry Lightning Risk Nationwide
Year: 2012
Meteorologists developed two formulas to predict the probability of dry lightning throughout the continental United States and Alaska and parts of Canada. Predictions are made daily and are accessible through the web at http://www.airfire.org/tools/daily-fi re-weather/dry-lightning-probability. The emphasis is on the western United States, where dry lightning is a more common occurrence. Predictions are based on identifying days on which lightning is expected and separately determining whether there is likely to be at least 1/10th inch of accompanying rain. The formulas are run with the…
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
Spatially extensive reconstructions show variable-severity fire and heterogeneous structure in historical western United States dry forests
Year: 2012
Aim Wildfire is often considered more severe now than historically in dry forests of the western United States. Tree-ring reconstructions, which suggest that historical dry forests were park-like with large, old trees maintained by low-severity fires,are from small, scattered studies. To overcome this limitation, we developed spatially comprehensive reconstructions across 927,000 ha in four landscapes, using anew method based on land surveys from c. 1880. Location Dry forests of the western United States. Methods We reconstructed forest structure for four large dry-forest landscapes using…
Publication Type: Journal Article
Strategic planning for instream flow restoration: a case study of potential climate change impacts in the central Columbia River basin
Year: 2012
We provide a case study prioritizing instream flow restoration activities by sub-basin according to the habitat needs of Endangered Species Act (ESA)-listed salmonids relative to climate change in the central Columbia River basin in Washington State (USA). The objective is to employ scenario analysis to inform and improve existing instream flow restoration projects. We assess the sensitivity of late summer (July, August, and September) flows to the following scenario simulations singly or in combination: climate change, changes in the quantity of water used for irrigation and possible changes…
Publication Type: Journal Article
Pole Creek Fire
Year: 2012
In September 9, 2012 a lightning strike hit the Pole Creek trailhead in the Deschutes National Forest, approximately 8 miles southwest of Sisters, Oregon. The wildfire was contained on October 17th after spreading over 26,000 acres of timber and brush. In response to this event, the Northwest Fire Science Consortium partnered with Oregon State University (OSU) College of Forestry, OSU Forestry & Natural Resources Extension, USFS Region 6, and the Central Oregon Fire Management Service to offer an opportunity for in-the-field learning in the immediate post-fire environment. Targeted…
Publication Type: Report
Photo Series for Quantifying Natural Fuels Volume XI : Eastern Oregon Sagebrush - Steppe and Spotted Owl Nesting Habitat in the Pacific Northwest
Year: 2012
Three series of photographs display a range of natural conditions and fuel loadings for sagebrush-steppe types that are ecotonal with grasses, western juniper, and ponderosa pine in eastern Oregon, and one series of photographs displays a range of natural conditions and fuel loadings for northern spotted owl nesting habitat in forest types in Washington and Oregon. Each group of photos includes inventory information summarizing vegetation composition, structure, and loading; woody material loading and density by size class; forest floor depth and loading; and various site characteristics. The…
Publication Type: Report
Climate-Induced Changes in Lake Ecosystem Structure Inferred from Coupled Neo- and Paleoecological Approaches
Year: 2012
Over the 20th century, surface water temperatures have increased in many lake ecosystems around the world, but long-term trends in the vertical thermal structure of lakes remain unclear, despite the strong control that thermal stratification exerts on the biological response of lakes to climate change. Here we used both neo- and paleoecological approaches to develop a fossil-based inference model for lake mixing depths and thereby refine understanding of lake thermal structure change. We focused on three common planktonic diatom taxa, the distributions of which previous research suggests…
Publication Type: Journal Article
Integrating Theoretical Climate and Fire Effects on Savanna and Forest Systems
Year: 2012
The role of fire and climate in determining savanna and forest distributions requires comprehensive theoretical reevaluation. Empirical studies show that climate constrains maximum tree cover and that fire feedbacks can reduce tree cover substantially, but neither the stability nor the dynamics of these systems are well understood. A theoretical integration of rainfall effects with fire processes in particular is lacking. We use simple, well-supported assumptions about the percolation dynamics of fire spread and the demographic effects of climate and fire on trees to build a dynamic model…
Publication Type: Journal Article
Simulating effects of climate change and ecological restoration on fire behaviour in a south-western USA ponderosa pine forest
Year: 2012
Global climate change has the potential to affect future wildfire activity, particularly in south-western USA ponderosa pine forests that have been substantially altered by land-use practices and aggressive fire suppression. Using two regional general circulation models for the A1B greenhouse gas emission scenario, Australia's CSIRO:MK3 and Germany's MPIM:ECHAMS, we predicted fire behaviour under the 80th, 90th and 97th percentiles of future fire-weather conditions at a study site on the Kaibab National Forest, Arizona. We then altered the fuel structure by simulating alternative ecological…
Publication Type: Journal Article
Changes in Soil Chemical and Biological Properties After Thinning and Prescribed Fire for Ecosystem Restoration in a Rocky Mountain Douglas Fir Forest
Year: 2012
Practices such as thinning followed by prescribed burning, often termed ‘ecosystem restoration practices’, are being used in Rocky Mountain forests to prevent uncontrolled wildfire and restore forests to pre-settlement conditions. Prior to burning, surface fuels may be left or collected into piles, which may affect fire temperatures and attendant effects on the underlying soil. The objective of this study is to determine which pre-fire fuel management treatments best reduce fuel loadings without causing fire temperatures high enough to impair soil chemical and biological properties. Five fuel…
Publication Type: Journal Article
Reducing hazardous fuels on nonindustrial private forests: factors influencing landowner decisions
Year: 2011
In mixed-ownership landscapes, fuels conditions on private lands have implications for fire risk on public lands and vice versa. The success of efforts to mitigate fire risk depends on the extent, efficacy, and coordination of treatments on nearby ownerships. Understanding factors in forest owners’ decisions to address the risk of wildland fire is therefore important. This research uses logistic regression to analyze mail survey data and identify factors in forest owners’ decisions to reduce hazardous fuels in the ponderosa pine (Pinus ponderosa) ecosystem on the east side of Oregon. Results…
Publication Type: Journal Article
Ponderosa Pine Biomass Relationships Vary with Site Treatment and Site Productivity
Year: 2011
Allometric equations, which express biomass as a function of tree size, are often used to estimate the amount of fuel in a site’s canopy. Most managers assume that one allometric equation per species is sufficient, or that any error introduced by extrapolation is irrelevant. This work showed, however, that the allometric biomass relationship for ponderosa pine likely changes over space and time. The researchers concluded that for maximum accuracy, allometric equations for ponderosa pine should account for stand management history and site productivity. Thinned trees replaced their foliage…
Publication Type: Report
Simulating fuel treatment effects in dry forests of the western United States: testing the principles of a fire-safe forest
Year: 2011
We used the Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS) to simulate fuel treatment effects on 45 1 62 stands in low- to midelevation dry forests (e.g., ponderosa pine (Pinus ponderosa Doug!. ex. P. & C. Laws.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) of the western United States. We evaluated treatment effects on predicted post-treatment fire behavior (fire type) and fire hazard (torching index). FFE-FVS predicts that thinning and surface fuel treatments reduced crown fire behavior relative to no treatment; a large proportion of stands were…
Publication Type: Journal Article
Consume 3.0 -- A Software Tool for Computing Fuel Consumption
Year: 2009
Knowing when, where and how fire should be applied is critical for land managers planning to use fire prescriptively for land management goals, or allowing fires ignited naturally to burn. Myriad variables need to be taken into consideration to determine how fire will consume different fuels. Consume, version 3.0 is a user-friendly software that incorporates the Fuel Characteristic Classification System (FCCS) to predict fuel consumption, pollutant emissions, and heat release. A flexible tool, Consume 3.0 makes these calculations based on fuel loadings, fuel moisture and other environmental…
Publication Type: Report
Response of antelope bitterbrush to repeated prescribed burning in Central Oregon ponderosa pine forests
Year: 2009
Antelope bitterbrush is a dominant shrub in many interior ponderosa pine forests in the western United States. How it responds to prescribed fire is not well understood, yet is of considerable concern to wildlife and fire managers alike given its importance as a browse species and as a ladder fuel in these fire-prone forests. We quantified bitterbrush cover, density, and biomass in response to repeated burning in thinned ponderosa pine forests. Low- to moderate-intensity spring burning killed the majority of bitterbrush plants on replicate plots. Moderately rapid recovery of bitterbrush…
Publication Type: Journal Article
The evaluation of meta-analysis techniques for quantifying prescribed fire effects on fuel loadings
Year: 2009
Models and effect-size metrics for meta-analysis were compared in four separate meta-analyses quantifying surface fuels after prescribed fires in ponderosa pine (Pinus ponderosa Dougl. ex Laws.) forests of the Western United States. An aggregated data set was compiled from 8 published reports that contained data from 65 fire treatment units. Downed woody and organic fuels were partitioned into five classes, and four meta-analyses were performed on each in a 2 by 2 factorial combination of fixed-effects vs. mixed-effects models with a difference-based metric (Hedges’ d) vs. a ratio-based…
Publication Type: Report
Lessons of the Hayman fire: weeds, woodpeckers and fire severity
Year: 2008
This project took advantage of pre-fire data gathered within the perimeter of Colorado’s 2002 Hayman Fire. Researchers studied the unique fire regime of Front Range ponderosa pine forests, and fire effects on understory-plant communities and American Three-toed Woodpeckers. Results confirmed that historically, the diverse structure of these forests was maintained by a mixed-severity fire regime that included large areas of severe fire. In addition, researchers found that much of the burn meets habitat requirements for American Three-toed Woodpeckers, and that understory plant species that…
Publication Type: Report
In a Ponderosa Pine Forest, Prescribed Fires Reduce the Likelihood of Scorched Earth
Year: 2008
The Malheur National Forest is located in the Blue Mountains on Oregon’s eastern side, the portion of the state that lies east of the Cascade Crest. In the mid 1990s, researchers and land managers conceived a suite of experiments to explore the effects of prescribed fire on forest health. The studies were designed to coincide with prescribed burns conducted by the USDA Forest Service. The experiments took place in the Emigrant Creek Ranger District, a remote area dominated by ponderosa pine. One of the research projects aimed to assess soil health after different intervals of fire frequency…
Publication Type: Report