Research Database
Displaying 1 - 8 of 8
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
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
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
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
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
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
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
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