Research Database
Displaying 81 - 100 of 104
Spatiotemporal patterns of unburned areas within fire perimeters in the northwestern United States from 1984 to 2014
Year: 2018
A warming climate, fire exclusion, and land cover changes are altering the conditions that produced historical fire regimes and facilitating increased recent wildfire activity in the northwestern United States. Understanding the impacts of changing fire regimes on forest recruitment and succession, species distributions, carbon cycling, and ecosystem services is critical, but challenging across broad spatial scales. One important and understudied aspect of fire regimes is the unburned area within fire perimeters; these areas can function as fire refugia across the landscape during and after…
Publication Type: Journal Article
Improving forest sampling strategies for assessment of fuel reduction burning
Year: 2017
Land managers typically make post hoc assessments of the effectiveness of fuel reduction burning (FRB), but often lack a rigorous sampling framework. A general, but untested, assumption is that variability in soil and fuel properties increases from small (∼1 m) to large spatial scales (∼10–100 km). Based on a recently published field-based sampling scheme, we addressed the following questions: (i) How much variability is captured in measurements collected at different spatial scales? (ii) What is the optimal number of sampling plots required for statistically robust characterisation of burnt…
Publication Type: Journal Article
Human exposure and sensitivity to globally extreme wildfire events
Year: 2017
Extreme wildfires have substantial economic, social and environmental impacts, but there is uncertainty whether such events are inevitable features of the Earth’s fire ecology or a legacy of poor management and planning. We identify 478 extreme wildfire events defined as the daily clusters of fire radiative power from MODIS, within a global 10 × 10 km lattice, between 2002 and 2013, which exceeded the 99.997th percentile of over 23 million cases of the ΣFRP 100 km−2 in the MODIS record. These events are globally distributed across all flammable biomes, and are strongly associated with extreme…
Publication Type: Journal Article
A LiDAR-based analysis of the effects of slope, vegetation density, and ground surface roughness on travel rates for wildland firefighter escape route mapping
Year: 2017
Escape routes are essential components of wildland firefighter safety, providing pre-defined pathways to a safety zone. Among the many factors that affect travel rates along an escape route, landscape conditions such as slope, low-lying vegetation density, and ground surface roughness are particularly influential, and can be measured using airborne light detection and ranging (LiDAR) data. In order to develop a robust, quantitative understanding of the effects of these landscape conditions on travel rates, we performed an experiment wherein study participants were timed while walking along a…
Publication Type: Journal Article
Landscape-scale quantification of fire-induced change in canopy cover following mountain pine beetle outbreak and timber harvest
Year: 2017
Across the western United States, the three primary drivers of tree mortality and carbon balance are bark beetles, timber harvest, and wildfire. While these agents of forest change frequently overlap, uncertainty remains regarding their interactions and influence on specific subsequent fire effects such as change in canopy cover. Acquisition of pre- and post-fire Light Detection and Ranging (LiDAR) data on the 2012 Pole Creek Fire in central Oregon provided an opportunity to isolate and quantify fire effects coincident with specific agents of change. This study characterizes the influence of…
Publication Type: Journal Article
Returning Fire to the Land—Celebrating Traditional Knowledge and Fire
Year: 2017
North American tribes have traditional knowledge about fire effects on ecosystems, habitats, and resources. For millennia, tribes have used fire to promote valued resources. Sharing our collective understanding of fire, derived from traditional and western knowledge systems, can benefit landscapes and people. We organized two workshops to investigate how traditional and western knowledge can be used to enhance wildland fire and fuels management and research. We engaged tribal members, managers, and researchers to formulate solutions regarding the main topics identified as important to tribal…
Publication Type: Journal Article
1984–2010 trends in fire burn severity and area for the conterminous US
Year: 2016
Burn severity products created by the Monitoring Trends in Burn Severity (MTBS) project were used to analyse historical trends in burn severity. Using a severity metric calculated by modelling the cumulative distribution of differenced Normalized Burn Ratio (dNBR) and Relativized dNBR (RdNBR) data, we examined burn area and burn severity of 4893 historical fires (1984–2010) distributed across the conterminous US (CONUS) and mapped by MTBS. Yearly mean burn severity values (weighted by area), maximum burn severity metric values, mean area of burn, maximum burn area and total burn area were…
Publication Type: Journal Article
Opportunities to utilize traditional phenological knowledge to support adaptive management of social-ecological systems vulnerable to changes in climate and fire regimes
Year: 2016
The field of adaptive management has been embraced by researchers and managers in the United States as an approach to improve natural resource stewardship in the face of uncertainty and complex environmental problems. Integrating multiple knowledge sources and feedback mechanisms is an important step in this approach. Our objective is to contribute to the limited literature that describes the benefits of better integrating indigenous knowledge (IK) with other sources of knowledge in making adaptive-management decisions. Specifically, we advocate the integration of traditional phenological…
Publication Type: Journal Article
Mapping post-fire habitat characteristics through the fusion of remote sensing tools
Year: 2016
Post-fire snags provide important resources for cavity nesting communities as well as being subject to timber removal through salvage logging practices. Tools that can characterize their distributions along with other features important as wildlife habitat, such as woody shrub cover, would be useful for research and management purposes. Three dimensional lidar data and Landsat time series disturbance products have both shown varying promise in their ability to characterize aspects of dead biomass and understory cover, but studies exploring the combination of the remote sensing datasets…
Publication Type: Journal Article
Relating Fire-Caused Change in Forest Structure to Remotely Sensed Estimates of Fire Severity
Year: 2016
Fire severity maps are an important tool for understanding fire effects on a landscape. The relative differenced normalized burn ratio (RdNBR) is a commonly used severity index in California forests, and is typically divided into four categories: unchanged, low, moderate, and high. RdNBR is often calculated twice—from images collected the year of the fire (initial assessment) and during the summer of the year after the fire (extended assessment). Both collection times have been calibrated to field measurements, but field data with both pre-fire and post-fire observations of matched plots are…
Publication Type: Journal Article
Review of broad-scale drought monitoring of forests: Toward an integrated data mining approach
Year: 2016
Efforts to monitor the broad-scale impacts of drought on forests often come up short. Drought is a direct stressor of forests as well as a driver of secondary disturbance agents, making a full accounting of drought impacts challenging. General impacts can be inferred from moisture deficits quantified using precipitation and temperature measurements. However, derived meteorological indices may not meaningfully capture drought impacts because drought responses can differ substantially among species, sites and regions. Meteorology-based approaches also require the characterization of current…
Publication Type: Journal Article
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 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
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
Traditional Ecological Knowledge: A Model for Modern Fire Management?
Year: 2014
For many thousands of years, aboriginal peoples worldwide used fire to manage landscapes. In NorthAmerica, the frequency and extent of fire (both human caused and natural) were much reduced afterEuropean colonization. Fire exclusion became the policy in the United States for most of the 20thcentury as the country became more settled and industrialized. Past fire exclusion has helped producelandscapes that are highly susceptible to uncharacteristically severe wildfire. An urgent challengefor land managers today is to reduce fire risk through several means, including prescribed burning,without…
Publication Type: Report
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
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
Social science research on Indigenous wildfire management in the 21st century and future research needs
Year: 2014
This article reviews social science research on Indigenous wildfire management in Australia, Canada and the United States after the year 2000 and explores future research needs in the field. In these three countries, social science research exploring contemporary Indigenous wildfire management has been limited although there have been interesting findings about how Indigenous culture and knowledge influences fire management. Research with Indigenous communities may be limited not because of a lack of interest by social scientists, but rather by obstacles to doing research with Indigenous…
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
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