Research Database
Displaying 41 - 52 of 52
Wildfire and the Future of Water Supply
Year: 2014
In many parts of the world, forests provide high quality water for domestic, agricultural, industrial, and ecological needs, with water supplies in those regions inextricably linked to forest health. Wildfires have the potential to have devastating effects on aquatic ecosystems and community drinking water supply through impacts on water quantity and quality. In recent decades, a combination of fuel load accumulation, climate change, extensive droughts, and increased human presence in forests have resulted in increases in area burned and wildfire severity—a trend predicted to continue. Thus,…
Publication Type: Journal Article
Five-year legacy of wildfire and salvage logging impacts on nutrient runoff and aquatic plant, invertebrate, and fish productivity
Year: 2014
Ecohydrological linkages between phosphorus (P) production, stream algae, benthic invertebrate, and fish communities were studied for 4 years after severe wildfire in the Rocky Mountains (Alberta, Canada). Mean concentrations of all forms of P (soluble reactive, total dissolved, particulate, and total) were 2 to 13 times greater in burned and post-fire salvage-logged streams than in unburned streams (p < 0.001). Post-disturbance recovery of P was slow with differences in P-discharge relationships still evident 5 years after the fire (p < 0.001). Coupled P and sediment interactions were…
Publication Type: Journal Article
The relationship of large fire occurrence with drought and fire danger indices in the western USA, 1984-2008: the role of temporal scale
Year: 2013
The relationship between large fire occurrence and drought has important implications for fire prediction under current and future climates. This study’s primary objective was to evaluate correlations between drought and fire-danger-rating indices representing short- and long-term drought, to determine which had the strongest relationships with large fire occurrence at the scale of the western United States during the years 1984–2008. We combined 4–8-km gridded drought and fire-danger-rating indices with information on fires greater than 404.7 ha (1000 acres). To account for differences in…
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
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
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
Harmful filamentous cyanobacteria favoured by reduced water turnover with lake warming
Year: 2012
Anthropogenic-induced changes in nutrient ratios have increased the susceptibility of large temperate lakes to several effects of rising air temperatures and the resulting heating of water bodies. First, warming leads to stronger thermal stratification, thus impeding natural complete water turnover (holomixis), which compensates for oxygen deficits in the deep zones. Second, increased water temperatures and nutrient concentrations can directly favour the growth of harmful algae. Thus, lake-restoration programmes have focused on reducing nutrients to limit toxic algal blooms. Here we present…
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
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
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
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