Research Database
Displaying 101 - 120 of 122
Management of cheatgrass fuel loading in the shrub-steppe
Year: 2013
The fire risk experiment was in plant communities that spanned the range of B. tectorum cover. Bromus tectorum cover was grouped into five classes. Each replicate is comprised of 8 to 18 plots in the three lowest B. tectorum cover classes and 2 to 6 plots at the two highest cover classes. A replicate is a collection of plots where the risk of fire was determined as the proportion of plots that burned. Each class has four replicates. We used 176 square plots, 10 m on a side. Two hundred twenty six plots, 10 m on a side, were used to related B. tectorum cover…
Publication Type: Presentation
Wildland firefighter entrapment avoidance: modelling evacuation triggers
Year: 2013
Wildland firefighters are often called on to make tactical decisions under stressful conditions in order to suppress a fire. These decisions can be hindered by human factors such as insufficient knowledge of surroundings and conditions, lack of experience, overextension of resources or loss of situational awareness. One potential tool for assisting fire managers in situations where human factors can hinder decision-making is the Wildland–Urban Interface Evacuation (WUIVAC) model, which models fire minimum travel times to create geographic trigger buffers for evacuation recommendations.…
Publication Type: Journal Article
Does seeding after wildfires in rangelands reduce erosion or invasive species?
Year: 2013
Mitigation of ecological damage caused by rangeland wildfires has historically been an issue restricted to the western United States. It has focused on conservation of ecosystem function through reducing soil erosion and spread of invasive plants. Effectiveness of mitigation treatments has been debated recently. We reviewed recent literature to conduct a meta-analysis of seeding after wildfires to determine if seedings may (1) protect ecosystems against soil erosion and (2) reduce invasion or abundance of undesirable nonnative plant species. Effectiveness of postfire seedings was examined in…
Publication Type: Journal Article
Research and development supporting risk-based wildfire effects prediction for fuels and fire management: status and needs
Year: 2013
Wildland fire management has moved beyond a singular focus on suppression, calling for wildfire management for ecological benefit where no critical human assets are at risk. Processes causing direct effects and indirect, long-term ecosystem changes are complex and multidimensional. Robust risk-assessment tools are required that account for highly variable effects on multiple values-at-risk and balance competing objectives, to support decision making. Providing wildland fire managers with risk-analysis tools requires a broad scientific foundation in fire behaviour and effects prediction as…
Publication Type: Journal Article
The effects of large wildfires on employment and wage growth and volatility in the western United States
Year: 2013
We examined the effect of large wildfires on economic growth and volatility in the western United States. We matched wildfire data with quarterly employment and earnings growth data to assess the specific effect of wildfire on employment and wage growth in western US counties. Wildfires generally tended to exhibit positive effects on employment and wage growth in the quarter(s) during which suppression efforts were active. However, this effect transitioned to increased economic volatility following a wildfire. The effect of wildfire also varied by the type of county in which wildfire occurred…
Publication Type: Journal Article
Conditions favouring Bromus tectorum dominance of endangered sagebrush steppe ecosystems
Year: 2013
Ecosystem invasibility is determined by combinations of environmental variables, invader attributes, disturbance regimes, competitive abilities of resident species and evolutionary history between residents and disturbance regimes. Understanding the relative importance of each factor is critical to limiting future invasions and restoring ecosystems. We investigated factors potentially controlling Bromus tectorum invasions into Artemisia tridentata ssp. wyomingensis communities across 75 sites in the Great Basin. We measured soil texture, cattle grazing intensity, gaps among perennial plants…
Publication Type: Journal Article
Sagebrush steppe recovery after fire varies by development phase of Juniperus occidentalis woodland
Year: 2013
Woodland ecosystems of the world have been changed by land use demands, altered fire regimes, invasive species and climate change. Reduced fire frequency is recognised as a main causative agent for Pinus–Juniperus L. (piñon–juniper) expansion in North American woodlands. Piñon–juniper control measures, including prescribed fire, are increasingly employed to restore sagebrush steppe communities. We compared vegetation recovery following prescribed fire on Phase 2 (mid-succession) and Phase 3 (late-succession) Juniperus occidentalis Hook. (western juniper) woodlands in Oregon. The herbaceous…
Publication Type: Journal Article
Management of Cheatgrass Fuel Loading in the Shrub-Steppe
Year: 2013
The Columbia Basin Natural Wildlife Refuge (CNWR) had been periodically grazed until the Refuge was established in 1944. Cheatgrass became a prominent plant in the area. In 1986 a fire occurred near the study area. The area was reseeded with Elymus wawawaiensis (Snake River Wheatgrass, Secar cultivar). This grass has established reducing cheatgrass cover to very low levels. The study area was established in 2002 to test hypotheses on the effects of herbicides on plant community structure and establishment of Elymus wawawaiensis. In 2002 study plots were established and characterized before…
Publication Type: Report
Preemergent Control of Medusahead on California Annual Rangelands with Aminopyralid
Year: 2012
Medusahead (Taeniatherum caput-medusae [L.] Nevski), the most problematic invasive grass on many California rangelands, is difficult to control selectively in grasslands. Prescribed burning, grazing, and herbicides have been tested with some success but are not practical in all situations. The selective herbicide aminopyralid, normally used for control of certain broadleaf species such as thistles, suppresses some annual grasses when applied pre- or early postemergence. In 2009–2010, we tested the efficacy of aminopyralid for medusahead control in preemergence applications at three foothill…
Publication Type: Journal Article
Predicting the Occurrence of Downy Brome (Bromus tectorum) in Central Oregon
Year: 2012
Where the nonnative annual grass downy brome proliferates, it has changed ecosystem processes, such as nutrient, energy, and water cycles; successional pathways; and fire regimes. The objective of this study was to develop a model that predicts the presence of downy brome in Central Oregon and to test whether high presence correlates with greater cover. Understory data from the U.S. Department of Agriculture (USDA) Forest Service's Current Vegetation Survey (CVS) database for the Deschutes National Forest, the Ochoco National Forest, and the Crooked River National Grassland were compiled, and…
Publication Type: Journal Article
Forest Service Spending on Large Wildfires in the West
Year: 2012
The purpose of this report is to shed light on fire suppression spending as a starting point for understanding the economic impacts of large fires. In this paper, we examined Forest Service suppression spending during and after large wildfire events to explore: (1) what the Forest Service spends money on during and after a wildfire; (2) the kinds of entities and personnel that perform that work; and (3) where funds went.
Publication Type: Report
Cheating Cheatgrass: New research to combat a wily invasive weed
Year: 2012
Cheatgrass and its cousin, red brome, are exotic annual grasses that have invaded and altered ecosystem dynamics in more than 41 million acres of desert shrublands between the Rockies and the Cascade-Sierra chain. A fungus naturally associated with these Bromus species has been found lethal to the plants’ soil-banked dormant seeds. Supported by the Joint Fire Science Program (JFSP), researchers Susan Meyer, Phil Allen, and Julie Beckstead cultured this fungus, Pyrenophora semeniperda, in the laboratory and developed an experimental field application that, in some trials, killed all the…
Publication Type: Report
Trajectories of change in sagebrush steppe vegetation communities in relation to multiple wildfires
Year: 2012
Repeated perturbations, both biotic and abiotic, can lead to fundamental changes in the nature of ecosystems, including changes in state. Sagebrush steppe communities provide important habitat for wildlife and grazing for livestock. Fire is an integral part of these systems, but there is concern that increased ignition frequencies and invasive species are fundamentally altering them. Despite these issues, the majority of studies of fire effects in systems dominated by Artemisia tridentata wyomingensis have focused on the effects of single burns. The Arid Lands Ecology Reserve (ALE), in south-…
Publication Type: Journal Article
The Effect of Large Wildfires on Local Labor Markets
Year: 2012
Although fire managers, policymakers, and communities are benefiting from better understanding of suppression costs, property losses, and community impacts of large fires, no generalizable empirical research has quantified the specific effect of large wildfires on local employment and wages. As federal spending on wildfire suppression in the United States continues to grow, an understanding of the effects of wildfires on local economies will help natural resource managers, policymakers, and communities better anticipate and make management and policy decisions that support local economies.…
Publication Type: Report
Grassland Response to Herbicides and Seeding of Native Grasses 6 Years Posttreatment
Year: 2012
Herbicides are the primary method used to control exotic, invasive plants. This study evaluated restoration efforts applied to grasslands dominated by an invasive plant, sulfur cinquefoil, 6 yr after treatments. Of the five herbicides we evaluated, picloram continued to provide the best control of sulfur cinquefoil over 6 yr. We found the timing of picloram applications to be important to the native forb community. Plots with picloram applied in the fall had greater native forb cover. However, without the addition of native perennial grass seeds, the sites became dominated by exotic grasses.…
Publication Type: Journal Article
Wildfire Suppression Contracting: The Effect of Local Business Capacity During Large Wildfires
Year: 2012
Contracting capacity and local capture can be the result of local economic conditions (supply side conditions) as well as agency contracting practices (demand side conditions). In order to capture contracts locally, local businesses that can perform the work need to exist, and past experience contracting with the federal government is a reasonable indicator of that capacity. To better understand local contracting capacity, we examined how local contract capture varied between wildfires and the relationship between local capture and contracting capacity measures. We investigated how the number…
Publication Type: Report
Ecological restoration using EBIPM
Year: 2012
When managing rangeland impacted by weeds, land managers often encounter plant communities where remnant desired vegetation is very scarce. When rangeland is this degraded, simply controlling weeds with the expectation that desired plants will be released from competition and return to dominate the site over time might not be adequate. Introducing propagules (i.e., seeds) of desired species through revegetation might be required. Ecologically Based Invasive Plant Management (EBIPM) serves as a decision-making framework for planning and implementing restoration and revegetation programs. This…
Publication Type: Journal Article
Synthesis of Knowledge of Extreme Fire Behavior: Volume I for Fire Managers
Year: 2011
The National Wildfire Coordinating Group definition of extreme fire behavior (EFB) indicates a level of fire behavior characteristics that ordinarily precludes methods of direct control action. One or more of the following is usually involved: high rate of spread, prolific crowning/spotting, presence of fire whirls, and strong convection column. Predictability is difficult because such fires often exercise some degree of influence on their environment and behave erratically, sometimes dangerously. Alternate terms include “blow up” and “fire storm.” Fire managers examining fires over the last…
Publication Type: Report
Synthesis of Knowledge on the Effects of Fire and Thinning Treatments on Understory Vegetation in U.S. Dry Forests
Year: 2009
The results of this synthesis illustrate several important lessons. First, current forest structure is the result of decades of fire-suppression activities, and so restoration will require multiple treatments to bring forests to within the range of historic variation. Second, while the treatments discussed in this document generally increased native plant responses, the same treatments also increased exotic plant response. Therefore, to avoid spread of exotic plant species, it is important to consider the context of the treatment area, (e.g., nearby roads, wildland urban interface, previous…
Publication Type: Report
Has Fire Suppression Increased the Amount of Carbon Stored in Western US Forests?
Year: 2008
Active 20th century fire suppression in western US forests, and a resulting increase in stem density, is thought to account for a significant fraction of the NorthAmerican carbon sink. We compared California forest inventories from the 1930s with inventories from the 1990s to quantify changes in aboveground biomass. Stem density in mid-montane conifer forests increased by 34%, while live aboveground carbon stocks decreased by 26%. Increased stem density reflected an increase in the number of small trees and a net loss of large trees. Large trees contain a disproportionate amount of carbon,…
Publication Type: Journal Article