Research Database
Displaying 81 - 91 of 91
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
Clearcutting and high severity wildfire have comparable effects on growth of direct-seeded interior Douglas-fir
Year: 2014
The degree to which harvesting can achieve comparable beneficial effects to wildfire on seedling establishment is a key factor in understanding regeneration dynamics in dry interior forest ecosystems. We compared the capacity of harvesting versus wildfire to support establishment of directly-seeded interior Douglas-fir over a three-year period in the interior Douglas-fir biogeoclimatic zone of British Columbia. The mixed-severity McLure Fire of August 2003 affected over 26,000 hectares in the central British Columbia, Canada. Within the fire-affected area, we assessed growth performance in…
Publication Type: Journal Article
Fire severity and tree regeneration following bark beetle outbreaks: the role of outbreak stage and burning conditions
Year: 2014
The degree to which recent bark beetle (Dendroctonus ponderosae) outbreaks may influence fire severity and postfire tree regeneration is of heightened interest to resource managers throughout western North America, but empirical data on actual fire effects are lacking. Outcomes may depend on burning conditions (i.e., weather during fire), outbreak severity, or intervals between outbreaks and subsequent fire. We studied recent fires that burned through green-attack/red-stage (outbreaks <3 years before fire) and gray-stage (outbreaks 3–15 years before fire) subalpine forests dominated by…
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
Natural tree regeneration and coarse woody debris dynamics after a forest fire in the Western Cascade range
Year: 2013
We monitored coarse woody debris dynamics and natural tree regeneration over a 14-year period after the 1991 Warner Creek Fire, a 3631-ha (8,972-ac) mixed severity fire in the western Cascade Range of Oregon. Rates for tree mortality in the fire, postfire mortality, snag fall, and snag fragmentation all showed distinct patterns by tree diameter and species, with Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) more likely to survive a fire, and to remain standing as a snag, than other common tree species. Natural seedling regeneration was abundant, rapid, and highly variable in space.…
Publication Type: Report
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