Research Database
Displaying 81 - 100 of 107
Post-fire logging produces minimal persistent impacts on understory vegetation in northeastern Oregon, USA
Year: 2016
Post-fire forest management commonly requires accepting some negative ecological impacts from management activities in order to achieve management objectives. Managers need to know, however,whether ecological impacts from post-fire management activities are transient or cause long-term ecosystem degradation. We studied the long-term response of understory vegetation to two post-fire loggingtreatments – commercial salvage logging with and without additional fuel reduction logging – on a long-term post-fire logging experiment in northeastern Oregon, USA. We sampled understory plant coverand…
Publication Type: Journal Article
Long-term effects of wildfire on greater sage-grouse - integrating population and ecosystem concepts for management in the Great Basin
Year: 2015
Greater sage-grouse (Centrocercus urophasianus; hereinafter, sage-grouse) are a sagebrush obligate species that has declined concomitantly with the loss and fragmentation of sagebrush ecosystems across most of its geographical range. The species currently is listed as a candidate for federal protection under the Endangered Species Act (ESA). Increasing wildfire frequency and changing climate frequently are identified as two environmental drivers that contribute to the decline of sage-grouse populations, yet few studies have rigorously quantified their effects on sage-grouse populations across…
Publication Type: Report
Restoration handbook for sagebrush steppe ecosystems with emphasis on greater sage-grouse habitat—Part 1. Concepts for understanding and applying restoration
Year: 2015
Sagebrush steppe ecosystems in the United States currently occur on only about one-half of their historical land area because of changes in land use, urban growth, and degradation of land, including invasions of non-native plants. The existence of many animal species depends on the existence of sagebrush steppe habitat. The greater sage-grouse (Centrocercus urophasianus) is a landscape-dependent bird that requires intact habitat and combinations of sagebrush and perennial grasses to exist. In addition, other sagebrush-obligate animals also have similar requirements and restoration of…
Publication Type: Report
Restoration handbook for sagebrush steppe ecosystems with emphasis on greater sage-grouse habitat—Part 2. Landscape level restoration decisions
Year: 2015
Sagebrush steppe ecosystems in the United States currently (2015) occur on only about one-half of their historical land area because of changes in land use, urban growth, and degradation of land, including invasions of non-native plants. The existence of many animal species depends on the existence of sagebrush steppe habitat. The greater sage-grouse (Centrocercus urophasianus) is a landscape-dependent bird that requires intact habitat and combinations of sagebrush and perennial grasses to exist. In addition, other sagebrush-obligate animals also have similar requirements and restoration of…
Publication Type: Report
Sources and implications of bias and uncertainty in a century of US wildfire activity data
Year: 2015
Analyses to identify and relate trends in wildfire activity to factors such as climate, population, land use or land cover and wildland fire policy are increasingly popular in the United States. There is a wealth of US wildfire activity data available for such analyses, but users must be aware of inherent reporting biases, inconsistencies and uncertainty in the data in order to maximise the integrity and utility of their work. Data for analysis are generally acquired from archival summary reports of the federal or interagency fire organisations; incident-level wildfire reporting systems of…
Publication Type: Journal Article
Mapping day-of-burning with coarse-resolution satellite fire-detection data
Year: 2014
Evaluating the influence of observed daily weather on observed fire-related effects (e.g. smoke production, carbon emissions and burn severity) often involves knowing exactly what day any given area has burned. As such, several studies have used fire progression maps – in which the perimeter of an actively burning fire is mapped at a fairly high temporal resolution – or MODIS satellite data to determine the day-of-burning, thereby allowing an evaluation of the influence of daily weather. However, fire progression maps have many caveats, the most substantial being that they are rarely mapped…
Publication Type: Journal Article
Landsat time series and lidar as predictors of live and dead basal area across five bark beetle-affected forests
Year: 2014
Bark beetle-caused tree mortality affects important forest ecosystem processes. Remote sensing methodologies that quantify live and dead basal area (BA) in bark beetle-affected forests can provide valuable information to forest managers and researchers. We compared the utility of light detection and ranging (lidar) and the Landsat-based detection of trends in disturbance and recovery (LandTrendr) algorithm to predict total, live, dead, and percent dead BA in five bark beetle-affected forests in Alaska, Arizona, Colorado, Idaho, and Oregon, USA. The BA response variables were predicted from…
Publication Type: Journal Article
Mapping the daily progression of large wildland fires using MODIS active fire data
Year: 2014
High temporal resolution information on burnt area is needed to improve fire behaviour and emissions models. We used the Moderate Resolution Imaging Spectroradiometer (MODIS) thermal anomaly and active fire product (MO(Y)D14) as input to a kriging interpolation to derive continuous maps of the timing of burnt area for 16 large wildland fires. For each fire, parameters for the kriging model were defined using variogram analysis. The optimal number of observations used to estimate a pixel’s time of burning varied between four and six among the fires studied. The median standard error from…
Publication Type: Journal Article
Is fire exclusion in mountain big sagebrush communities prudent? Soil nutrient, plant diversity and arthropod response to burning.
Year: 2014
Fire has largely been excluded from many mountain big sagebrush communities. Managers are reluctant to reintroduce fire, especially in communities without significant conifer encroachment, because of the decline in sagebrush-associated wildlife. Given this management direction, a better understanding of fire exclusion and burning effects is needed. We compared burned to unburned plots at six sites in Oregon. Soil nutrient availability generally increased with burning. Plant diversity increased with burning in the first post-burn year, but decreased by the third post-burn year. Burning altered…
Publication Type: Journal Article
Challenges of assessing fire and burn severity using field measures, remote sensing and modelling
Year: 2014
Comprehensive assessment of ecological change after fires have burned forests and rangelands is important if we are to understand, predict and measure fire effects. We highlight the challenges in effective assessment of fire and burn severity in the field and using both remote sensing and simulation models. We draw on diverse recent research for guidance on assessing fire effects on vegetation and soil using field methods, remote sensing and models. We suggest that instead of collapsing many diverse, complex and interacting fire effects into a single severity index, the effects of fire should…
Publication Type: Journal Article
Songbird response to wildfire in mixed-conifer forest in south-western Oregon
Year: 2014
We used 1 year of pre-fire and 4 years of post-fire data to quantify changes in the occurrence of birds at burned and unburned sites in a southern Oregon watershed after a 2500-ha wildfire. Our objectives were to identify bird species that increased or decreased as a result of this mixed-severity fire. Of the 27 species we investigated, we found evidence for fire-induced changes in the proportion of sites occupied by 13 species. Of these, most (8 species) were species that occurred at fewer sites after the fire than before. These changes were consistent with changes in vegetation composition…
Publication Type: Journal Article
Assessing the quality of forest fuel loading data collected using public participation methods and smartphones
Year: 2014
Effective wildfire management in the wildland–urban interface (WUI) depends on timely data on forest fuel loading to inform management decisions. Mobile personal communication devices, such as smartphones, present new opportunities to collect data in the WUI, using sensors within the device – such as the camera, global positioning system (GPS), accelerometer, compass, data storage and networked data transfer. In addition to providing a tool for forest professionals, smartphones can also facilitate engaging other members of the community in forest management as they are now available to a…
Publication Type: Journal Article
Is burn severity related to fire intensity? Observations from landscape scale remote sensing
Year: 2013
Biomass burning by wildland fires has significant ecological, social and economic impacts. Satellite remote sensing provides direct measurements of radiative energy released by the fire (i.e. fire intensity) and surrogate measures of ecological change due to the fire (i.e. fire or burn severity). Despite anecdotal observations causally linking fire intensity with severity, the nature of any relationship has not been examined over extended spatial scales. We compare fire intensities defined by Moderate Resolution Imaging Spectroradiometer Fire Radiative Power (MODIS FRP) products with Landsat-…
Publication Type: Journal Article
The push and pull of climate change causes heterogeneous shifts in avian elevational ranges
Year: 2012
Projected effects of climate change on animal distributions primarily focus on consequences of temperature and largely ignore impacts of altered precipitation. While much evidence supports temperature-driven range shifts, there is substantial heterogeneity in species' responses that remains poorly understood. We resampled breeding ranges of birds across three elevational transects in the Sierra Nevada Mountains, USA, that were extensively surveyed in the early 20th century. Presence absence comparisons were made at 77 sites and occupancy models were used to separate significant range shifts…
Publication Type: Journal Article
Meta-analysis of avian and small-mammal response to fire severity and fire surrogate treatments in US fire-prone forests
Year: 2012
Management in fire-prone ecosystems relies widely upon application of prescribed fire and/or fire surrogate (e.g., forest thinning) treatments to maintain biodiversity and ecosystem function. Recently, published literature examining wildlife response to fire and fire management has increased rapidly. However, none of this literature has been synthesized quantitatively, precluding assessment of consistent patterns of wildlife response among treatment types. Using meta- analysis, we examined the scientific literature on vertebrate demographic responses to burn severity (low/moderate, high),…
Publication Type: Journal Article
Pattern and process of prescribed fires influence effectiveness at reducing wildfire severity in dry coniferous forests
Year: 2012
We examined the effects of three early season (spring) prescribed fires on burn severity patterns of summer wildfires that occurred 1–3 years post- treatment in a mixed conifer forest in central Idaho. Wildfire and prescribed fire burn severities were estimated as the difference in normalized burn ratio (dNBR) using Landsat imagery. We used GIS derived vegetation, topography, and treatment variables to generate models predicting the wildfire burn severity of 1286–5500 30- m pixels within and around treated areas. We found that wildfire severity was significantly lower in treated areas than in…
Publication Type: Journal Article
Projecting future distributions of ecosystem climate niches: Uncertainties and management applications
Year: 2012
Projecting future distributions of ecosystems or species climate niches has widely been used to assess the potential impacts of climate change. However, variability in such projections for the future periods, particularly the variability arising from uncertain future climates, remains a critical challenge for incorporating these projections into climate change adaptation strategies. We combined the use of a robust statistical modeling technique with a simple consensus approach consolidating projected outcomes for multiple climate change scenarios, and exemplify how the results could guide…
Publication Type: Journal Article
Climatic, Landform, Microtopographic, and Overstory Canopy Controls of Tree Invasion in a Subalpine Meadow Landscape, Oregon Cascades, USA
Year: 2012
Tree invasions have been documented throughout Northern Hemisphere high elevation meadows, as well as globally in many grass and forb-dominated ecosystems. Tree invasions are often associated with large-scale changes in climate or disturbance regimes, but are fundamentally driven by regeneration processes influenced by interactions between climatic, topographic, and biotic factors at multiple spatial scales. The purpose of this research was to quantify spatiotemporal patterns of meadow invasion; and how climate, larger landforms, topography, and overstory trees have interactively influenced…
Publication Type: Journal Article
Eco-Evolutionary Responses of Biodiversity to Climate Change
Year: 2012
Climate change is predicted to alter global species diversity, the distribution of human pathogens and ecosystem services. Forecasting these changes and designing adequate management of future ecosystem services will require predictive models encompassing the most fundamental biotic responses. However, most present models omit important processes such as evolution and competition. Here we develop a spatially explicit eco-evolutionary model of multi-species responses to climate change. We demonstrate that both dispersal and evolution differentially mediate extinction risks and biodiversity…
Publication Type: Journal Article
Delayed Phenology and Reduced Fitness Associated with Climate Change in a Wild Hibernator
Year: 2012
The most commonly reported ecological effects of climate change are shifts in phenologies, in particular of warmer spring temperatures leading to earlier timing of key events. Among animals, however, these reports have been heavily biased towards avian phenologies, whereas we still know comparatively little about other seasonal adaptations, such as mammalian hibernation. Here we show a significant delay (0.47 days per year, over a 20-year period) in the hibernation emergence date of adult females in a wild population of Columbian ground squirrels in Alberta, Canada. This finding was related…
Publication Type: Journal Article