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2009 Science Accomplishments Report > Threat Characterization and Management Program Accomplishments >

Key Accomplishments of the Threat Characterization and Management Program in 2009

Program Mission

The mission of the Threat Characterization and Management Program is to generate knowledge about the nature, causes, and consequences of large, rapid, or significant changes to ecosystems that potentially threaten societal values. We will use our knowledge to develop and deliver innovative and effective strategies, methods, and tools so people can plan, manage, or mitigate the changes, causes, and consequences.

Research Problem Statements

Problem 1: How do we characterize and measure the cause, occurrence, extent, and consequences of threatening conditions and people's perceptions of them?

Problem 2: How do ecological or social processes interact across multiple temporal and spatial scales to create potential threats?

Problem 3: What thresholds exist in ecosystem dynamics; what are the biological, physical, and social consequences of crossing these thresholds; and how do people perceive and respond to disturbances that are approaching or have crossed their biological or physical thresholds?

Problem 4: How are ecological patterns and processes managed to reduce the probability, magnitude, and consequences of a threat?

Problem 5: What is the range of possible future conditions, and what are the uncertainties and tradeoffs associated with them?

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Key Findings

New method quantifies potential effects of fuel treatments on carbon stocks

Do fuel reduction treatments result in a net gain or loss of carbon stored in forests? If fuel treatments reduce future fire severity, then less carbon dioxide is released to the atmosphere, and the treatments could result in carbon gains. When considered individually, however, thinning and underburning treatments result in a net loss of carbon, but what is their effect on carbon storage outside the treatment units?

To begin answering these questions, scientists developed a risk-based approach to determine expected offsets from landscape-scale fuel management activities. The approach is being tested on the 198,000-acre Drews Watershed of the Fremont-Winema National Forest. Preliminary results suggest that in this particular forest ecosystem, there were extensive carbon benefits outside the treatment area in terms of reduced likelihood of wildfire, but the carbon loss specifically from treatment activities resulted in an overall loss of carbon on the entire landscape. Over time, depending on decomposition rates in the dead trees and rates of regeneration, the carbon loss within the treated area could be reversed. These methods will help forest managers balance demands for reduced fire risk and increasing carbon storage as a climate change mitigation strategy.

Contact: Alan Ager,, Western Wildland Environmental Threat Assessment Center

Partners: Oregon Department of Forestry; USDA Forest Service Fremont-Winema National Forest, Rocky Mountain Research Station, and Forest Health Enterprise Technology Team; West Coast Regional Sequestration Partnership (WESTCARB)


click to expand/collapse.Climate is a principal environmental control on wildfire

Station scientists, working with university collaborators, demonstrated that the area of wildfire burned in the American West was significantly controlled by climate (combinations of precipitation, temperature, and drought) during most of the 20th century (1916–2003). Climate-fire relationships differed by vegetation type, represented by 16 ecoprovinces (broad geographic regions with similar ecological properties) across the West. Fire in most mountainous ecoprovinces, except in the arid Southwest, is driven by low precipitation, dry conditions, and high temperatures in the summer fire season. Fire in arid ecoprovinces, or those dominated by grasses or shrubs, is strongly associated with precipitation or drought in the previous year, which affects the amount of fuel for the current year. Despite the influences of fire exclusion, other land use changes, or both, the amount of burned area is still substantially controlled by climate. In the future, this will likely depend on ecosystem- specific seasonal variation in climate and its effects on fuel conditions in northern mountainous ecosystems and fuel availability in arid ecosystems.

Understanding fire-climate relationships, which differ for different ecosystems, will help land managers anticipate changing fire regimes in response to global warming and predict fire patterns associated with multiannual and interdecadal climatic variability. Despite the overarching influence of climate, it will be important to link this understanding of climate drivers to land use changes and broad-scale management strategies.

Contact: Don McKenzie, donaldmckenzie, Threat Characterization and Management Program

Partners: University of Washington; University of California, Merced


Effects of severe wildfire on watershed processes may last for decades

weather station on Entiat Experimental ForestRare, high-quality historical data are being used for model formulation, calibration, and testing to evaluate effects of a severe 1970 wildfire on flow regime and maintenance of water quantity and quality from streams draining forested headwaters. Following more than 25 years of inactivity at the Entiat Experimental Forest in eastern Washington, study watersheds were reinstrumented in 2004 with stream gauging, water quality, and meteorological stations to assess rate of recovery toward prefire conditions.

Preliminary results indicate that the wildfire resulted in initial peak flow increases in runoff of 100 percent or more from the burned area, and that these increases resulted from decreased evapotranspiration—the process through which plants draw up water—increased snow accumulation, and more rapid snowmelt. The effects of wildfire on watershed processes may be long lived and depend, in part, on rehabilitation actions.

This ongoing research is providing predictive capability regarding effects of severe wildfire and hydrologic recovery processes after a major disturbance. These findings are informing management decisions regarding the need and strategies for postfire rehabilitation. They lay the foundation for future investigation of hydrologic effects of fuel-reduction treatments.

Contact: Richard D. Woodsmith,, Threat Characterization and Management Program

Partners: Oregon State University; Stockholm University, Sweden; USDA Forest Service Okanogan-Wenatchee National Forest


Topography controlled historical fire patterns in eastern Washington

topography in eastern Washington historically helped contain wildfireTopography controlled historical fire patterns in eastern Washington Station scientists and collaborators have analyzed historical data for fires that burned between 1700 and 1900 in eastern Washington. These fires predate the fire suppression efforts of the 20th century and, therefore, provide valuable information about the historical fire regime in this mountainous region that experienced frequent, low-severity fires. By using these data, scientists developed computer simulation models that replicate complicated patterns of historical fire over space and time by tuning a few key parameters. They discovered mathematical relationships that reveal (1) the topographic complexity of fire-prone landscapes and (2) the relative influences of climate, topography, and fuels across multiple spatial and temporal scales.

This analysis yielded two pieces of information that are unprecedented in firehistory research: (1) statistical properties of topographic controls (such as ridges or canyons) on fire spread and (2) estimates of historical fire-size distributions. The 200- year data set, precise information on fire locations, spatial statistics, and these simulations are enabling researchers to glean more information about historical fire regimes than would be possible from reconstructing individual fires. This work makes it possible to identify landscapes where small changes in environmental drivers, such as climate, might lead to significant changes in fire regimes by overriding the topographic controls on fire spread.

Contact: Don McKenzie,, Threat Characterization and Management Program

Partner: University of Washington


Genetics regulate concentrations of potential defense compounds in ponderosa pine

genetics study on ponderosa pine reveals differents among seed sourcesResearch clearly demonstrated that genetics regulate the concentrations of foliar piperidine alkaloids in ponderosa pine. These alkaloids are potential tree defense compounds against insects or pathogens. The highest quantities were found in seedlings originating along the western margin of ponderosa pine's range in California, Oregon, and Washington. The lowest quantities were observed in seedlings from regions either in, or east of, the Cascades and Sierra Nevada mountains. No latitudinal gradient was detected among regions. The contribution of various seedling growth parameters and climatic conditions at the sites of parental seed sources were evaluated for their influence on the variability of alkaloid levels but were found to be only marginally important.

Measurements of alkaloid concentrations have the potential to function as an independent physiological indicator of tree or stand vigor and overall health for ponderosa pine. Future research will examine if trees with higher alkaloid levels are more resistant to attack from insects or pathogens.

Contact: Rick Kelsey,, Threat Characterization and Management Program or Brad St. Clair,, Land and Watershed Management Program


Scientists identify genetic differences between populations of Douglas-fir beetle

researchers removes bark from an infested Douglas-fir treeThe Douglas-fir bark beetle occurs in Douglas-fir forests in northern Mexico, western United States, and southwestern Canada. The beetle is a significant source of mortality for Douglas-fir. It is a particular problem in Mexico where Douglas-fir is considered a threatened species.

Scientists identified a new subspecies of Douglas-fir beetles from a population in northern Mexico, based primarily on differences in physical characteristics. Variation within bark beetle species is important because it can mean different control tactics could be effective against different populations. Scientists tested multiple populations throughout the distribution of this beetle for genetic differences and found that Douglas-fir beetle has high intra- and inter-population genetic variation compared with several other bark beetles. These analyses also suggest that the genetic structure of this bark beetle species is strongly influenced by isolation resulting from geographic distance between populations. The observed genetic differences between northern (Canada- United States) and southern (Mexico) populations confirm that these two sets of populations correspond to previously assigned subspecies. Because of these differences between subspecies, beetle management tools that have been used successfully in Canada and the United States may need to be modified to be effective against populations in Mexico.

Contact: Jane Hayes,, Threat Characterization and Management Program

Partners: Eastern Oregon University, Instituto Politecnico Nacional de Mexico


New methods yield improved estimates of current forest conditions

The Forest Service's Forest Inventory and Analysis Program has been collecting and analyzing data on our Nation's forests since the 1930s. This information is used by decisionmakers to decide policy, law, and regulation of forests at the state and federal level; by forest managers to understand the status and changes in the forest; and by the general public and researchers to understand how forests are affected by broad socioeconomic and ecological change.

In the Western United States, established forest plots are remeasured every 10 years. Forest managers, state and federal agencies, and other groups that need information about the current status of forests would prefer more current information. To help meet this need, station and university scientists explored using current remote-sensing data and previous measurements from national forests in Oregon and Washington to update plot information. By comparing the modeled outcomes with known conditions, they were able to identify a more accurate statistical method for updating plot information. They also identified ways to improve commonly used "nearest neighbor" methods for updating or filling in missing data. These findings could be used to support the Resource Planning Act, which requires the Forest Service to assess the Nation's forest lands every 10 years.

Contact: Tara Barrett,, Threat Characterization and Management Program

Partner: Oregon State University



Model simulations quantify differences among fuel-reduction treatments

Scientists evaluated the effects of simulated thinning and surface fuel treatments on 45,000 stands in low- to midelevation dry forests in the Western United States using the Fire and Fuels Extension to the Forest Vegetation Simulator (FFEFVS). They found that thinning treatments that left 50 or 100 trees per acre were more effective at reducing crown fire hazard than thinning treatments that left 200 or 300 trees per acre. Prescribed fire was the most effective surface fuel treatment.

This is the first study to statistically test treatment effects with FFE-FVS. These results support inferences from recent empirical studies about stand density and fuel structures on crown fire hazard. The concurrence of results from modeling and empirical studies provides quantitative support for "fire-safe" principles of forest fuel reduction. This study quantified what would constitute significant differences among a variety of thinning treatments. These findings will help forest and fire managers develop effective treatment options for reducing potential fire behavior in dry forests of the Western United States.

Contact: Morris C. Johnson,, Threat Characterization and Management Program

Partners: USDA Forest Service Forest Management Service Center and Forest Vegetation Simulator Group


Scientists develop national-scale protocol for estimating fire hazard and risk

At the request of the national Wildland Fire Leadership Council, station scientists and partners developed a risk assessment protocol: First Approximation of Fire Hazard and Fire Risk. This formal risk framework uses spatially defined estimates of the annual likelihood of fire, the expected intensity, and the fire effects— positive and negative—on values such as wildlife habitat, energy infrastructure, recreation, and human population density. This protocol will be used to establish a baseline from which national trends in wildland fire hazard can be monitored. Results from the project will also be used to strategically plan fuel-reduction treatments over time to mitigate ecological and human loss from wildfire.

Contact: Alan Ager,, Western Wildland Environmental Threat Assessment Center

Partner: USDA Forest Service Rocky Mountain Research Station


Risk assessment helps prioritize fuel treatments

Where will fuel-reduction treatments be most effective? This is a key question for land managers challenged by a finite budget and public expectations to protect specific highly valued resources while meeting goals to restore fire resilience to large forested landscapes. Focusing treatments in and around the wildland-urban interface to protect human property, for example, is less efficient and perhaps not compatible with landscape restoration goals to change the behavior of large fires.

Work by station scientists and managers on the Deschutes National Forest demonstrated how risk assessment tools can be used to measure the relative wildfire risk to the wide array of human and ecological values found on federal lands. These analyses can guide management activities to protect specific resources including habitat conservation efforts for threatened and endangered species, such as the northern spotted owl, in fire-prone areas. Scientists also analyzed fuel-reduction strategies on a wildland-urban area, typical of eastern Oregon, abutting the Wallowa-Whitman National Forest. Both studies revealed spatial variation in burn probability and intensity that is useful for prioritizing fuelreduction treatments.

Contact: Alan Ager,, Western Wildland Environmental Threat Assessment Center

Partners: USDA Forest Service Deschutes National Forest and Rocky Mountain Research Station


Postfire seeding does not reduce soil erosion following wildfire

reseeding studies on the Okanogan-Wenatchee National ForestSlope stabilization treatments are applied after severe wildfires to increase soil cover, reduce soil erosion, protect water quality, and reduce risks to human life and property. The effectiveness of many common slope stabilization treatments, such as reseeding, remains in question, however. Station scientists assessed different reseeding treatments after several recent fires on the Okanogan-Wenatchee National Forest. They found that seeding winter wheat over portions of the burned area produced little or no additional soil cover following high-severity wildfires in the dry coniferous forest. They also tried seeding yarrow, a perennial native forb, and found this often increased cover of yarrow significantly, particularly when applied in combination with nitrogen fertilizer. In general they found the increased cover of seeded species was often offset by reduced cover of native, nonseeded vegetation. These findings suggest that seeded species compete with recovering native vegetation for limited soil resources after wildfire in dry coniferous forests, and that efforts to monitor the effectiveness of slope stabilization treatments by measuring seeded species cover alone are likely to overestimate treatment effects on soil cover, runoff, and erosion.

Contact: Dave W. Peterson, davepeterson, Threat Characterization and Management Program

Partners: USDA Forest Service Okanogan- Wenatchee National Forest, USDA-USDI Joint Fire Science Program


New method predicts spring budburst under different climate scenarios

New method predicts spring budburst under different climate scenarios Most tree species have a chilling requirement (exposure to a certain amount of cold weather) and a forcing requirement (enough warm weather to trigger budburst) before the buds will burst in the spring. The chilling requirement is a protective mechanism that prevents budburst during warm spells midwinter. Results from a recent study indicate that the temperature range that will satisfy the chilling requirement for Douglas-fir is wider than previously appreciated. A new approach to modeling spring budburst calculates the temperature combinations that meet both chilling and forcing requirements and predicts the timing of spring budburst for historical and possible future climate scenarios. It predicts budburst will occur earlier in the spring with moderate winter warming; however, if substantial winter warming occurs, the model predicts budburst will be delayed because reduced winter chilling would increase the requirement for forcing temperatures. The modeling approach is consistent with reports from the literature for multiple species; thus, it may apply quite broadly.

Contact: Constance Harrington, charrington, Threat Characterization and Management Program

Partners: Oregon State University, Washington Department of Natural Resources, Webster Nursery



10-foot spacing is optimal for longer term management of Douglas-fir

Olympic National Forest, WashingtonGrowth and mortality responses of Douglas-fir spaced 3 to 20 feet apart were compared among three sites of contrasting quality in Washington and British Columbia. During 25 years of stand development, stands planted at a 10-foot spacing maintained a high level of tree vigor and stability. They also experienced little or no competition-induced mortality. The relationship between stem diameter and stand volumes suggests that the 10-foot spacing enabled growth to be allocated equitably to development of tree size and stand yield. Each of these results provides supporting evidence that, independent of site quality, planting stands at a 10-foot spacing results in a desirable starting point for subsequent management of Douglas-fir plantations. The research provides a biological basis for selecting appropriate planting spacings for Douglas-fir. Foresters will be able to compare effects of initial spacing on tree vigor, stability, and mortality and on stand growth and yield for sites that differ substantially in quality.

Contact: Timothy B. Harrington, tharrington, Threat Characterization and Management Program

Partner: USDA Forest Service Gifford Pinchot National Forest


Level of hardwood control leads to distinct stand structures in Douglas-fir plantations

different treatments as part of a vegetation management studyA vegetation management study initiated in 1983 continues to yield important results about longer term management of Douglasfir. At age 1 to 2 years, sprouts of tanoak and other evergreen hardwoods were treated with herbicides to reduce their abundance in two Douglas-fir plantations. The conifers were thinned at age 16 to 17 years to leave densities of 120 to 190 dominant trees per acre. Depending on initial density of hardwoods, three distinct stand structures emerged 8 years later. (1) Highly productive, pure stands of Douglas-fir (39 to 52 feet tall) occurred where hardwoods were completely removed. (2) Where 25 percent of the original hardwood density was retained, moderately productive stands of conifers (39 feet tall) overtopped the hardwoods (23 feet tall). (3) Where the original hardwood density was retained, conifers and hardwoods occupied the same canopy layer in a mixed stand of low productivity (26 to 30 feet tall).

In southwestern Oregon, initial hardwood density in Douglas-fir plantations affects how the stands will respond to a subsequent precommercial thinning. The three stand structures that developed by age 24 to 25 years represent different opportunities for managing stands to produce habitat for wildlife and wood products for future harvest.

Contact: Timothy B. Harrington, tharrington, Threat Characterization and Management Program

Partners: USDA Forest Service Siskiyou National Forest, USDI Bureau of Land Management, Medford District


Learning about forest processes deepens cultural knowledge

students learning about wetland plantsAt a 4-day culture camp organized by the Tlingit and Haida Central Council, Alaska youth and elders connected through cultural activities that provided the youth with an opportunity to learn about the traditional way of life and gain a deeper understanding of how culture plays a role in daily life. The cultural learning piece focused on invasive species, plants, and the environment. Station scientists talked with participants about forest processes and climate change. The station also hosted a world-renowned ethnobotanist who taught participants how different cultures use plants as foods, medicines, textiles, and in rituals.

Contact: Paul Hennon,, Threat Characterization and Management Program

Partners: Administration for American Indians, Central Council of Tlingit and Haida Indian Tribes of Alaska, Environmental Protection Agency



Carbon Offset Analysis with ArcFuels

Description: ArcFuels is a library of command functions (macros) within ArcMap® GIS software developed to streamline fire behavior modeling and spatial analyses for fuel treatment planning. ArcFuels now includes new analytical functions that allow users to analyze expected carbon offsets from fuel treatments and other management activities.

Use: Land managers can examine detailed carbon budgets for stands and landscapes and examine the effects of proposed management on carbon stocks.

How to get it:

Contact: Alan Ager,, Western Wildland Environmental Threat Assessment Center



Current and future habitat suitability maps for invasive tamarisk species

Description: Tamarisk species are shrubs or small trees considered by some to be among the most aggressively invasive and potentially detrimental exotic plants in the United States. Climate change has the potential to significantly affect the species habitat and distribution. These maps illustrate where tamarisk currently grows in Idaho, Oregon, and Washington, and where future habitat conditions may facilitate its spread.

Use: Public land managers and private landowners will find these maps useful. Understanding invasive species distribution and habitat is critical for early detection and to coordinate management responses and eradicate species before they become widely established.

How to get it: Kerns, B.K.; Naylor, B.J.; Buonopane, M.; Parks, C.G.; Rogers, B. 2009. Modeling tamarisk (Tamarix spp.) habitat and climate change effects in the Northwestern United States. Invasive Plant Science and Management. 2: 200–215.

Contact: Becky K. Kerns,, Western Wildland Environmental Threat Assessment Center


Web Page: Daily updates on new fire weather indicator

Description: A new Web page was developed to assist the Northwest Coordination Center (NWCC) evaluate fire danger from ongoing wildland fires. The NWCC coordinates logistics support, aviation support, and predictive services for all state and federal agencies involved in wildland fire management and suppression in Oregon and Washington.

The Web page provides daily updates on the "downdraft convective available potential energy" in the region, a quantitative meteorological measure that appears to track severe fire weather. This information helps fire managers plan for safety and resource deployment.

Use: Predictive Service Meteorologists at the Northwest Coordination Center access the page almost daily.

How to get it:

Contact: Brian Potter,, Threat Characterization and Management Program


Wildland Threat Mapper

Description: This virtual Earth viewer integrated with a search engine facilitates analysis of distribution and co-occurrence of various wildland threats and the values they affect. The search engine searches more than 30,000 global Internet map servers for spatial data sets. Query results connect to the map server, and map data are loaded directly into ArcGIS Explorer® where potential interactions can be identified. The search engine can also be used to locate a wide range of other natural resource data on a global scale.

Use: Geospatial analysts are using Wildland Threat Mapper to conduct a systematic assessment of Internet data relevant to wildland threat assessments.

Partner: USDA Forest Service Remote Sensing Application Center

Contact: Alan Ager,, Western Wildland Environmental Threat Assessment Center


US Forest Service - Pacific Northwest Research Station
Last Modified: Tuesday,26July2016 at16:45:14CDT

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