Research Database
Displaying 61 - 78 of 78
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
Pile Burning Effects on Soil Water Repellency, Infiltration, and Downslope Water Chemistry in the Lake Tahoe Basin, USA
Year: 2015
Thinning of conifers followed by pile burning has become a popular treatment to reduce fuel loads in the Lake Tahoe Basin, USA. However, concern has been voiced about burning within or near riparian areas because of the potential effect on nutrient release and, ultimately, lake water quality. Our objective was to quantify the effects of pile burning on soil physical and chemical properties and resulting near-stream surface and subsurface water chemistry. Twenty-seven hand-built piles of three contrasting fuelbed types (large wood, mixed-diameter slash, small-diameter slash) were burned. Burn…
Publication Type: Journal Article
Fire, Fuels, and Streams: The Effects and Effectiveness of Riparian Treatments
Year: 2015
Fire is an important disturbance in riparian systems—consuming vegetation; increasing light;creating snags and debris flows; altering habitat structure; and affecting stream conditions, erosion, andhydrology. For many years, land managers have worked to keep fire out of riparian systems through theuse of buffers. A number of projects funded by the Joint Fire Science Program are shedding light onthe dynamics of fire in riparian systems. Recent research and field practice have shown that (1) ripariantreatments can be beneficial and are not as risky as previously thought; and (2) riparian…
Publication Type: Report
Post-fire response of riparian vegetation in a heavily browsed environment
Year: 2015
Severe wildfires infrequently occur in large heterogeneous riparian valleys. Riparian areas may affect fire behavior and the pattern of burning due to saturated soils and patchy fuels that may have high moisture content in live and dead stems. We examined the effects of a severe fire on the dominant riparian vegetation: thin-leaf alder, river birch and willow, in a broad riparian valley in Rocky Mountain National Park, CO, USA. We mapped the canopy stem mortality and basal resprouting of 4507 first year post fire and 643 second year post fire individuals that had been the dominant woody…
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
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
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
Effects of burn status and conditioning on colonization of wood by stream macroinvertebrates
Year: 2014
The combination of changing climate and anthropogenic activities is increasing the probability of wildfire around the world. When fires occur in riparian zones, associated tree mortality can add wood directly to streams or wood may fall to the forest floor and remain there for some time before being transported into stream channels. Wood provides critical structure for aquatic macroinvertebrates, so our objectives were to assess the effects of wood burn status, conditioning, and their interaction on macroinvertebrate community composition, taxon and functional diversity, and trait affinities…
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
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
Wildfire severity mediates fluxes of plant material and terrestrial invertebrates to mountain streams
Year: 2012
Wildfire effects upon riparian plant community structure, composition, and distribution may strongly influence the dynamic relationships between riparian vegetation and stream ecosystems. However, few studies have examined the influence of fire on these processes. To that end, we compared the quantity and composition of allochthonous inputs of plant material and terrestrial invertebrates among stream tributaries characterized by various degrees of burn severity 5 years post-fire in the Frank Church Wilderness of central Idaho, USA. The magnitude of inputs of coniferous leaf litter to unburned…
Publication Type: Journal Article
Ecosystem Greenspots: Identifying Potential Drought, Fire, and Climate-Change Micro-Refuges
Year: 2012
In response to climate change and other threatening processes there is renewed interest in the role of refugia and refuges. In bioregions that experience drought and fire, micro-refuges can play a vital role in ensuring the persistence of species. We develop and apply an approach to identifying potential micro-refuges based on a time series of remotely sensed vegetation greenness (fraction of photosynthetically active radiation intercepted by the sunlit canopy; fPAR). The primary data for this analysis were NASA MODIS 16-day L3 Global 250 m (MOD13Q1) satellite imagery. This method draws upon…
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
Both topography and climate affected forest and woodland burn severity in two regions of the western US, 1984 to 2006
Year: 2011
Fire is a keystone process in many ecosystems of western North America. Severe fires kill and consume large amounts of above- and belowground biomass and affect soils, resulting in long-lasting consequences for vegetation, aquatic ecosystem productivity and diversity, and other ecosystem properties. We analyzed the occurrence of, and trends in, satellite-derived burn severity across six ecoregions in the Southwest and Northwest regions of the United States from 1984 to 2006 using data from the Monitoring Trends in Burn Severity project. Using 1,024 fires from the Northwest (4,311,871 ha) and…
Publication Type: Journal Article
Northwest Forest Plan -- The First 15 Years: Status and Trends of Northern Spotted Owl Populations and Habitats
Year: 2011
This is the second in a series of periodic monitoring reports on northern spotted owl (Strix occidentalis caurina) population and habitat trends on federally administered lands since implementation of the Northwest Forest Plan in 1994.Here we summarize results from a population analysis that included data from long- term demographic studies during 1985–2008. This data was analyzed separately by study area, and also in a meta-analysis across all study areas to assess temporal and spatial patterns in fecundity, apparent survival, recruitment, and annual rates of population change. Estimated…
Publication Type: Report
Prescribed fires as ecological surrogates for wildfires: A stream and riparian perspective
Year: 2010
Forest managers use prescribed fire to reduce wildfire risk and to provide resource benefits, yet little information is available on whether prescribed fires can function as ecological surrogates for wildfire in fire-prone landscapes. Information on impacts and benefits of this management tool on stream and riparian ecosystems is particularly lacking. We used a beyond-BACI (Before, After, Control, Impact) design to investigate the effects of a prescribed fire on a stream ecosystem and compared these findings to similar data collected after wildfire. For 3 years after prescribed fire treatment…
Publication Type: Journal Article
The fire pulse: wildfire stimulates flux of aquatic prey to terrestrial habitats driving increase in riparian consumers
Year: 2010
We investigated the midterm effects of wildfire (in this case, five years after the fire) of varying severity on periphyton, benthic invertebrates, emerging adult aquatic insects, spiders, and bats by comparing unburned sites with those exposed to low severity (riparian vegetation burned but canopy intact) and high severity (canopy completely removed) wildfire. We observed no difference in periphyton chlorophyll a or ash-free dry mass among different burn categories but did observe significantly greater biomass of benthic invertebrates in both high severity burned and unburned reaches versus…
Publication Type: Journal Article