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The Northwest Fire Science Consortium works to accelerate the awareness, understanding, and adoption of wildland fire science. We connect managers, practitioners, scientists, and local communities and collaboratives working on fire issues on forest and range lands in Washington and Oregon.

Learn more about NWFSC...

JFSP Regions


NWFSC is one of
fifteen regional exchanges
sponsored by the Joint Fire Science Program.

Hot Topics

Relating Fire-Caused Change in Forest Structure to Remotely Sensed Estimates of Fire Severity

Authored by J.M. Lydersen; Published 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 typically not available. This study uses a large network of field plots (n = 175) that was surveyed the year of and one year after a large wildfire in the central Sierra Nevada, USA, to quantify forest structure, mortality, and fire effects within fire severity categories from both the initial and extended RdNBR assessments. Most plots were classified in the same severity category in both assessments, particularly when mortality was high. Comparing initial and extended assessments, plots with lower pre-fire basal area were more likely to be classified at lower severity in the extended assessment, while plots with greater tree density were more likely to be classified at higher severity. High-severity plots had significantly greater pre-fire density of small trees. The high-severity category clearly captured stand-replacing fire effects (>95 % basal area mortality, >99 % tree density mortality), with typically all trees exhibiting high levels of crown consumption and scorching. In other severity categories, most large-sized and intermediate-sized trees survived, and moderate-severity fire favored survival of shade-intolerant species. Results suggest that both the initial and extended RdNBR assessments give an accurate representation of forest structural change in mixed-conifer forests following fire, particularly those of high severity.

Ecosystem resilience is evident 17 years after fire in Wyoming big sagebrush ecosystems

Authored by L.M. Ellsworth; Published 2016

Recent policy has focused on prevention of wildfire in the sagebrush steppe in an effort to protect habitat for the greater sage grouse (Centrocercus urophasianus). Historically, fire return intervals in Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) ecosystems were 50–100 yr or more, but invasive species, climate change, and a legacy of intensive grazing practices have led to degraded rangeland condition, altered fire regimes and fire effects, and declines in sagebrush cover. Little is known about the long-term impacts of fire in this ecosystem in areas where grazing pressure has been removed, few invasive species exist, and fire return intervals are maintained. In this study, we quantified vegetation composition prior to prescribed burning, 1 year following fire, and 17 years after fire in a native-dominated Wyoming big sagebrush ecosystem at Hart Mountain National Antelope Refuge, Oregon, United States. Seventeen years following fire, the ecosystem was dominated by native herbaceous vegetation, with 8.3% cover of broad-leaved forbs and bunchgrasses in the understory, compared to just 3.8% cover of native herbaceous vegetation in unburned controls. Invasive annual grass cover ranged from 0.2% to 8.4% across all treatments and years (P = 0.56). One year following fire, the distance from a randomly located point and the nearest mature sagebrush was 16.6 m, but by 17 years after the fire, that distance had decreased to 2.5 m. Seventeen years after fires, shrub cover was 0.4–4% in burned plots compared to 13–24% in unburned controls. Collectively, these data demonstrate that good condition ungrazed Wyoming big sagebrush plant communities exhibited resilience following fire and maintained a native-dominated mosaic of shrubs, bunchgrasses, and forbs. Further, unburned control plots were dominated by woody vegetation and exhibited losses in herbaceous understory, possibly indicating that they are outside of their natural fire return interval. Our results illustrate that management of all habitat components, including natural disturbance and a mosaic of successional stages, is important for persistent resilience and that suppression of all fires in the sagebrush steppe may create long-term losses of heterogeneity in good condition Wyoming big sagebrush ecosystems.

Emissions from prescribed burning of timber slash piles in Oregon

Authored by J. Aurell; Published 2017

Emissions from burning piles of post-harvest timber slash (Douglas-fir) in Grande Ronde, Oregon were sampled using an instrument platform lofted into the plume using a tether-controlled aerostat or balloon. Emissions of carbon monoxide, carbon dioxide, methane, particulate matter (PM2.5), black carbon, ultraviolet absorbing PM, elemental/organic carbon, filter-based metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzodioxins/dibenzofurans (PCDD/PCDF), and volatile organic compounds (VOCs) were sampled to determine emission factors, the amount of pollutant formed per amount of biomass burned. The effect on emissions from covering the piles with polyethylene (PE) sheets to prevent fuel wetting versus uncovered piles was also determined. Results showed that the uncovered (“wet”) piles burned with lower combustion efficiency and higher emission factors for VOCs, PM2.5, PCDD/PCDF, and PAHs. Removal of the PE prior to ignition, variation of PE size, and changing PE thickness resulted in no statistical distinction between emissions. Results suggest that dry piles, whether covered with PE or not, exhibited statistically significant lower emissions than wet piles due to better combustion efficiency.

Evaluating Prescribed Fire Effectiveness Using Permanent Monitoring Plot Data: A Case Study

Authored by K.M. Waring; Published 2016

Since Euro-American settlement, ponderosa pine forests throughout the western United States have shifted from high fire frequency and open canopy savanna forests to infrequent fire and dense, closed canopy forests. Managers at Zion National Park, USA, reintroduced fire to counteract these changes and decrease the potential for high-severity fires. We analyzed existing permanent monitoring plot data collected between 1995 and 2010 to assess achievement of management objectives related to prescribed fire in ponderosa pine forests. Following first entry fire, ponderosa pine (Pinus ponderosa C. Lawson var. scopulorum Engelm.) and Gambel oak (Quercus gambelii Nutt.) overstory and midstory densities declined between 10 % and 45 % and effectively shifted the Gambel oak diameter distribution toward larger trees. Second entry fires had a greater effect, reducing ponderosa pine and Gambel oak overstory and midstory densities between 24 % and 92 %. Diameter distributions of both species shifted toward fewer, larger trees following second entry fires. Total fuel load was reduced by <20 % in first entry fires and by half in second entry fires. Several objectives identified by the National Park Service (e.g., overstory ponderosa pine reduction) were not achieved with either fire entry; however, power analysis indicated that sample sizes were not adequate to fully detect long term changes following first entry fires. First entry, low intensity prescribed fire alone may not meet management objectives in southwestern ponderosa pine forests. We recommend using multiple fire entries or increased fire intensity if mechanical treatments are not also being utilized concurrently. Long term fire effects data is critical to adaptive management in national parks; however, the utility of this data could be improved through increased sample sizes, consistent data archiving, and regional scale analyses.

Modeling wildfire regimes in forest landscapes: abstracting a complex reality

Authored by D. McKenzie; Published 2015

Fire is a natural disturbance that is nearly ubiquitous in terrestrial ecosystems. The capacity to burn exists virtually wherever vegetation grows. In some forested landscapes, fi re is a principal driver of rapid ecosystem change, resetting succession ( McKenzie et al. 1996a ) and changing wildlife habitat (Cushman et al. 2011 ), hydrology ( Feikema et al. 2013 ), element cycles ( Smithwick 2011 ), and even landforms (Pierce et al. 2004 ). In boreal forests, for example, recurring wildfi res are the main cause of compositional and spatial patterns ( Wein and MacLean 1983 ), where a fi re-induced “shifting spatial mosaic” governs the heterogeneity in ecosystem patterns and processes on the landscape ( Goldammer and Furyaev 1996 ). In forest ecosystems where dominant species are long-lived, mature trees may provide a buffer against extreme weather such as drought or heat waves, but fi res and other disturbances such as insect outbreaks eliminate the buffering of the canopy, leaving a hotter and drier microclimate conducive to the establishment of new species. In a warming climate, fi re is expected to amplify and accelerate changes in forest composition, spatial pattern, and structure ( Littell et al. 2010 ; Loehman and Keane 2012 ; Raymond and McKenzie 2012 ; Cansler and McKenzie 2014 ). Anticipating these changes will be a key to successful forest management and conservation.

Restoring Fire's Role in Fire Adapted Communities

Webinar Event from Southern Fire Exchange

Webinar Summary

Prescribed fire is an effective forest and range management tool used to reduce wildfire fuels, manage understory vegetation, and restore/ manage ecosystems. Despite its utility, however, it is less commonly utilized in urban and community forest management. This webinar will talk about examples from Austin, Texas, where partners have successfully used prescribed fire to build on the concept of Fire Adapted Communities. Justice Jones will outline project goals, ecological objectives, critical partnerships, community outreach and education, technology and training, and lessons learned essential to the success of utilizing prescribed fire in the Wildland Urban Interface (WUI).

Register here.

Developing and Implementing Climate Change Adaptation Options in Forest Ecosystems: A Case Study in Southwestern Oregon, USA

Authored by J.E. Halofsky; Published 2016
Climate change will likely have significant effects on forest ecosystems worldwide. In Mediterranean regions, such as that in southwestern Oregon, USA, changes will likely be driven mainly by wildfire and drought. To minimize the negative effects of climate change, resource managers require tools and information to assess climate change vulnerabilities and to develop and implement adaptation actions. We developed an approach to facilitate development and implementation of climate change adaptation options in forest management. This approach, applied in a southwestern Oregon study region, involved establishment of a science–manager partnership, a science-based assessment of forest and woodland vulnerabilities to climate change, climate change education in multiple formats, hands-on development of adaptation options, and application of tools to incorporate climate change in planned projects. Through this approach, we improved local manager understanding of the potential effects of climate change in southwestern Oregon, and enabled evaluation of proposed management activities in the context of climatic stressors. Engaging managers throughout the project increased ownership of the process and outcomes, as well as the applicability of the adaptation options to on-the-ground actions. Science–management partnerships can effectively incorporate evolving science, regardless of the socio-political environment, and facilitate timely progress in adaptation to climate change. 

Filling the interspace—restoring arid land mosses: source populations, organic matter, and overwintering govern success

Authored by L.A. Condon; Published 2016

Biological soil crusts contribute to ecosystem functions and occupy space that could be available to invasive annual grasses. Given disturbances in the semiarid shrub steppe communities, we embarked on a set of studies to investigate restoration potential of mosses in sagebrush steppe ecosystems. We examined establishment and growth of two moss species common to the Great Basin, USA: Bryum argenteum and Syntrichia ruralis from two environmental settings (warm dry vs. cool moist). Moss fragments were inoculated into a third warm dry setting, on bare soil in spring and fall, both with and without a jute net and with and without spring irrigation. Moss cover was monitored in spring seasons of three consecutive years. Both moss species increased in cover over the winter. When Bryum received spring irrigation that was out of sync with natural precipitation patterns, moss cover increased and then crashed, taking two seasons to recover. Syntrichia did not respond to the irrigation treatment. The addition of jute net increased moss cover under all conditions, except Syntrichia following fall inoculation, which required a second winter to increase in cover. The warm dry population of Bryum combined with jute achieved on average 60% cover compared to the cool moist population that achieved only 28% cover by the end of the study. Differences were less pronounced for Syntrichia where moss from the warm dry population with jute achieved on average 51% cover compared to the cool moist population that achieved 43% cover by the end of the study. Restoration of arid land mosses may quickly protect soils from erosion while occupying sites before invasive plants. We show that higher moss cover will be achieved quickly with the addition of organic matter and when moss fragments originate from sites with a climate that is similar to that of the restoration site.

Did the 2002 Hayman Fire, Colorado, USA, Burn with Uncharacteristic Severity?

Authored by P.J. Fornwalt; Published 2016

There is considerable interest in evaluating whether recent wildfires in dry conifer forests of western North America are burning with uncharacteristic severity—that is, with a severity outside the historical range of variability. In 2002, the Hayman Fire burned an unlogged 3400 ha dry conifer forest landscape in the Colorado Front Range, USA, that had been the subject of previous fire history and forest age structure research. We opportunistically leveraged pre-existing data from this research, in combination with post-fire aerial imagery, to provide insight into whether the Hayman Fire’s patterns of high-severity, stand-replacing fire effects were uncharacteristic. Living old overstory trees were well distributed and abundant in the landscape before the Hayman Fire, despite the fact that some stand-replacing burning had been a component of the landscape’s historical mixed-severity fire regime. Of 106 randomly selected stand polygons that were sampled for the age of the oldest living overstory tree prior to the fire, 30 % contained only trees ≤200 yr, while 70 % contained at least one tree >200 yr and 29 % contained at least one tree >400 yr. Following the Hayman Fire, only 5 % of the polygons contained any living trees; these polygons were all immediately adjacent to the reservoir in the center of the landscape. At most, 4 % of the polygons contained one or more trees >200 yr post fire, and 3 % contained one or more trees >400 yr. The nearly complete loss of old trees, most of which were located in areas with evidence of past non-stand-replacing burning, leads us to conclude that the amount and extent of stand-replacing burning within the Hayman Fire were uncharacteristic for this landscape over at least the last two to four centuries.

Patterns of conifer regeneration following high severity wildfire in ponderosa pine-dominated forests

Webinar Event from Southwest Fire Science Consortium

Presenters: Marin Chambers, Colorado Forest Restoration Institute, CSU

Wildfires in ponderosa pine - dominated forests of the southern Rocky Mountains are increasingly burning with a high severity component that is unprecedented in the available historical record. The ability of ponderosa pine and other co-occurring conifers (e.g., Douglas-fir, Rocky Mountain juniper, Colorado blue spruce) to regenerate in uncharacteristically large severely burned patches of such fires is unclear, as seeds must disperse from surviving trees. We measured post-fire regenerating conifers in eleven 10+ year-old fires across Colorado, Wyoming, and South Dakota to characterize regeneration in severely burned patches, and how regeneration characteristics are governed by abiotic and biotic factors. Our results from the Colorado Front Range indicate that conifers have regenerated in severely burned areas, but at low densities (~100 stems ha-1). This contrasts with conifer regeneration in unburned and lightly to moderately burned areas, which was more than four times greater. Our Colorado results also illustrate that as distance from live trees increased, conifer regeneration decreased; transects averaged ~170 stems ha-1 25 m from the live forest edge and ~10 stems ha-1 250 m from the edge. Preliminary analyses from Wyoming and South Dakota indicate similar conifer regeneration densities in high severity burn areas in comparison to lightly to moderately burned and unburned areas. Additionally, as distance from living trees increased, post-fire conifer regeneration density sharply decreased, suggesting that it will likely be compromised in the interiors of large severely burned patches across the region. Click here to register NOW!

State of Fire: Risks, Effects, and Treatment Options

Lecture Event from Oregon Forest Resources Institute

State of Fire: Risks, Effects and Treatment Options. This updated presentation reviews the history of fire in Oregon's forests. It assesses the causes and effects of forest fires as well as options for reducing the vulnerability of Oregon’s forests to catastrophic fires. Also, you'll learn what can be done to enhance the recovery of forest ecosystems that have been damaged by fire. With the current dry conditions and low snowpack, there is increasing concern that there will be big wildfires this summer making this topic very timely.

Speaker: Sue Bowers , sbowers@certurytel.net

Past tree influence and prescribed fire mediate biotic interactions and community reassembly in a grassland-restoration experiment

Authored by C.B. Halpern; Published 2016

1. Woody plant encroachment of grasslands is occurring globally, with profound ecological consequences. Attempts to restore herbaceous dominance may fail if the woody state is resilient or if intervention leads to an alternate, undesirable state. Restoration outcomes often hinge on biotic interactions – particularly on priority effects that inhibit or promote community reassembly. 2. Following experimental tree removal from conifer-invaded grasslands, we documented substantial variation in community reassembly associated with the changing abundance of the native clonal sedge Carex inops L.H. Bailey subsp. inops. We explored possible mechanisms for this variation, focusing on the nature and timing of interactions between the meadow community and Carex and on how past tree influence and prescribed fire mediate the outcomes of these interactions. 3. Meadow species increased after tree removal, but less so in burned than in unburned plots. Carex expanded dramatically after fire, particularly where past tree influence had been greater. 4. Meadow species and Carex developed an increasingly negative association over time; preemption was reciprocal, but offset in time and space. Meadow species inhibited Carex through vegetative recovery in areas of limited or recent tree influence, irrespective of fire. Carex inhibited meadow reassembly in areas of greater tree influence, but only with burning. 5. Synthesis and applications. Tree removal and fire imposed across a range of altered meadow states yielded varying outcomes, reflecting biotic interactions and species’ regenerative traits that inhibited or promoted reassembly. Fire tended to destabilize the remnant meadow community and, in areas more degraded by encroachment, stimulated release of Carex, which inhibited reassembly. Knowledge of the context dependence of biotic interactions can enhance the effectiveness of restoration by establishing the bounds within which treatments produce desirable or undesirable outcomes.

Northwest Basin and Range Ecosystem Symposium

Symposium Event from Great Basin Landscape Conservation Cooperative

The Northwest Basin and Range Synthesis invites locals, scientists, managers, and the public to gather in Lakeview, Oregon for the 2017 Northwest Basin and Range Ecosystem Symposium. The event will include “state of the knowledge” presentations, and discussions on topics chosen by the NWBR Synthesis’s Steering Committee. On the first evening of the Symposium there will be a poster session, a series of brief presentations, and a keynote. 

Symposium Agenda

  • Panel #1: Wildlife Habitat Connectivity in the NW Basin and Range (Panelists: Phillip Street, UNR, Gail Collins, USFWS, Dr. John Tull, NDOW)
  • Panel #2: State of the Knowledge Around Changing Patterns of Water Availability on the Landscape (Panelists: Dr. Jason Dunham, USGS, Dr. Hank Johnson, USGS, Justin Ferrel, Lake County SWCD, Nicole Sullivan, TU, and others TBA) Discussion: Challenges and Opportunities of Natural Resource Management at the Landscape Scale
  • Panel #3: Sage-Steppe Habitat Management (Panelists: Dr. Chad Boyd, OSU-ARS, Jeremy Austin, ONDA, and others TBA)
  • Panel #4: Juniper, Weeds and Seeds: Terrestrial Habitat Restoration in the NW Basin and Range (Panelists: Dr. Kirk Davies, OSU-ARS, Grace Haskins, Lakeview BLM, Lindsay Davies, Burns BLM, and others TBA)
  • Ignite Session: A series of brief presentations about regional scientific research, findings from projects, regional collaborations and initiatives
  • Poster Session: Abstract submissions due by December 15, 2016, more details here.
  • BBQ, Refreshments and Keynote: TBA

Questions? Contact Levi Old, lold@thegreatbasininstitute.org