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• 1. [Article] Factors Influencing Residential Risk Perception in Fire-Prone Landscapes

  2012

  Citation × Citation Citation Abstract Copy Title: Factors Influencing Residential Risk Perception in Fire-Prone Landscapes Author: Vandeventer, Alexia 2012 Title: Factors Influencing Residential Risk Perception in Fire-Prone Landscapes Author: Vandeventer, Alexia 2012 Close

• 2. [Article] Factors Influencing Residential Risk Perception in Fire-Prone Landscapes

  2012

  Citation × Citation Citation Abstract Copy Title: Factors Influencing Residential Risk Perception in Fire-Prone Landscapes Author: Vandeventer, Alexia 2012 Title: Factors Influencing Residential Risk Perception in Fire-Prone Landscapes Author: Vandeventer, Alexia 2012 Close

• 3. [Article] Analyzing the transmission of wildfire exposure on a fire-prone landscape in Oregon, USA

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier ...

  Citation × Citation Citation Abstract Copy Title: Analyzing the transmission of wildfire exposure on a fire-prone landscape in Oregon, USA Author: Ager, Alan A., Vaillant, Nicole M., Finney, Mark A., Vance-Borland, Ken, Day, Michelle A. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/forest-ecology-and-management. Title: Analyzing the transmission of wildfire exposure on a fire-prone landscape in Oregon, USA Author: Ager, Alan A., Vaillant, Nicole M., Finney, Mark A., Vance-Borland, Ken, Day, Michelle A. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/forest-ecology-and-management. Close

• 4. [Article] The effects of fire on soil nitrogen associated with patches of the actinorhizal scrub Ceanothus cordulatus

  Nitrogen is a limiting resource in many temperate forests and nitrogen-fixing plants are usually limited to the early stages of post-disturbance succession. In fire-dependent Sierra Nevada forests, however, ...

  Citation × Citation Citation Abstract Copy Title: The effects of fire on soil nitrogen associated with patches of the actinorhizal scrub Ceanothus cordulatus Author: Oakley, Brian B., North, Malcolm P., Franklin, Jerry F. Nitrogen is a limiting resource in many temperate forests and nitrogen-fixing plants are usually limited to the early stages of post-disturbance succession. In fire-dependent Sierra Nevada forests, however, Ceanothus cordulatus is relatively abundant even in old-growth forest conditions which are at least partly maintained by fire. We conducted a field experiment to determine if soil beneath Ceanothus patches represent ‘resource islands’ of available N which persist after fire. Nine plots containing discrete patches of Ceanothus, Arctostaphylos patula (manzanita; chosen as a non N-fixing reference species), and bare forest floor were subjected to either a low-intensity (n = 3) or high intensity (n = 3) bum treatment, or remained unburned as controls (n = 3). Soil temperatures during the bum were monitored by a network of thermocouples placed at the surface of the mineral soil and at ca. 10 cm depths. Soil samples were collected from the organic horizon, 0-10 cm and 15-25 cm depths within each patch type immediately before burning and 2 days, and 6, and 11 months after. Soil moisture, total C and N, and ammonium and nitrate concentrations were determined in the laboratory. Before the burn, Ceanothus patches were significantly enriched in total and inorganic N in the organic horizon relative to the other patch types. A sharp increase in inorganic N was observed in all patch types and depths immediately following burning, but by 6 months after the burn, Ceanothus patches were significantly enriched relative to the surrounding patch types and remained so at months. Resprouting Ceanothus patches will continue to be an important source of a limiting nutrient in this fire-prone ecosystem. Title: The effects of fire on soil nitrogen associated with patches of the actinorhizal scrub Ceanothus cordulatus Author: Oakley, Brian B., North, Malcolm P., Franklin, Jerry F. Nitrogen is a limiting resource in many temperate forests and nitrogen-fixing plants are usually limited to the early stages of post-disturbance succession. In fire-dependent Sierra Nevada forests, however, Ceanothus cordulatus is relatively abundant even in old-growth forest conditions which are at least partly maintained by fire. We conducted a field experiment to determine if soil beneath Ceanothus patches represent ‘resource islands’ of available N which persist after fire. Nine plots containing discrete patches of Ceanothus, Arctostaphylos patula (manzanita; chosen as a non N-fixing reference species), and bare forest floor were subjected to either a low-intensity (n = 3) or high intensity (n = 3) bum treatment, or remained unburned as controls (n = 3). Soil temperatures during the bum were monitored by a network of thermocouples placed at the surface of the mineral soil and at ca. 10 cm depths. Soil samples were collected from the organic horizon, 0-10 cm and 15-25 cm depths within each patch type immediately before burning and 2 days, and 6, and 11 months after. Soil moisture, total C and N, and ammonium and nitrate concentrations were determined in the laboratory. Before the burn, Ceanothus patches were significantly enriched in total and inorganic N in the organic horizon relative to the other patch types. A sharp increase in inorganic N was observed in all patch types and depths immediately following burning, but by 6 months after the burn, Ceanothus patches were significantly enriched relative to the surrounding patch types and remained so at months. Resprouting Ceanothus patches will continue to be an important source of a limiting nutrient in this fire-prone ecosystem. Close

• 5. [Article] The effects of fire on soil nitrogen associated with patches of the actinorhizal shrub Ceanothus cordulatus

  Nitrogen is a limiting resource in many temperate forests and nitrogen-fixing plants are usually limited to the early stages of post-disturbance succession. In fire-dependent Sierra Nevada forests, however, ...

  Citation × Citation Citation Abstract Copy Title: The effects of fire on soil nitrogen associated with patches of the actinorhizal shrub Ceanothus cordulatus Author: Oakley, Brian B., Norht, Malcolm P., Franklin, Jerry F. Nitrogen is a limiting resource in many temperate forests and nitrogen-fixing plants are usually limited to the early stages of post-disturbance succession. In fire-dependent Sierra Nevada forests, however, Ceanothus cordulatus is relatively abundant even in old-growth forest conditions which are at least partly maintained by fire.We conducted a field experiment to determine if soil beneath Ceanothus patches represent ‘resource islands’ of available N which persist after fire. Nine plots containing discrete patches of Ceanothus, Arctostaphylos patula (manzanita; chosen as a non N-fixing reference species), and bare forest floor were subjected to either a low-intensity (n = 3) or highintensity (n = 3) bum treatment, or remained unburned as controls (n = 3). Soil temperatures during the bum were monitored by a network of thermocouples placed at the surface of the mineral soil and at ca. 10 cm depths. Soil samples were collected from the organic horizon, 0-10 cm and 15-25 cm depths within each patch type immediately before burning and 2 days, and 6, and 11 months after. Soil moisture, total C and N, and ammonium and nitrate concentrations were determined in the laboratory. Before the burn, Ceanothus patches were significantly enriched in total and inorganic N in the organic horizon relative to the other patch types. A sharp increase in inorganic N was observed in all patch types and depths immediately following burning, but by 6 months after the burn, Ceanothus patches were significantly enriched relative to the surrounding patch types and remained so at months. Resprouting Ceanothus patches will continue to be an important source of a limiting nutrient in this fire-prone ecosystem. Title: The effects of fire on soil nitrogen associated with patches of the actinorhizal shrub Ceanothus cordulatus Author: Oakley, Brian B., Norht, Malcolm P., Franklin, Jerry F. Nitrogen is a limiting resource in many temperate forests and nitrogen-fixing plants are usually limited to the early stages of post-disturbance succession. In fire-dependent Sierra Nevada forests, however, Ceanothus cordulatus is relatively abundant even in old-growth forest conditions which are at least partly maintained by fire.We conducted a field experiment to determine if soil beneath Ceanothus patches represent ‘resource islands’ of available N which persist after fire. Nine plots containing discrete patches of Ceanothus, Arctostaphylos patula (manzanita; chosen as a non N-fixing reference species), and bare forest floor were subjected to either a low-intensity (n = 3) or highintensity (n = 3) bum treatment, or remained unburned as controls (n = 3). Soil temperatures during the bum were monitored by a network of thermocouples placed at the surface of the mineral soil and at ca. 10 cm depths. Soil samples were collected from the organic horizon, 0-10 cm and 15-25 cm depths within each patch type immediately before burning and 2 days, and 6, and 11 months after. Soil moisture, total C and N, and ammonium and nitrate concentrations were determined in the laboratory. Before the burn, Ceanothus patches were significantly enriched in total and inorganic N in the organic horizon relative to the other patch types. A sharp increase in inorganic N was observed in all patch types and depths immediately following burning, but by 6 months after the burn, Ceanothus patches were significantly enriched relative to the surrounding patch types and remained so at months. Resprouting Ceanothus patches will continue to be an important source of a limiting nutrient in this fire-prone ecosystem. Close

• 6. [Article] Meta-analysis of avian and small-mammal response to fire severity and fire surrogate treatments in U.S. fire-prone forests

  This is the publisher’s final pdf. The published article is copyrighted by Ecological Society of America and can be found at: http://www.esa.org/.

  Citation × Citation Citation Abstract Copy Title: Meta-analysis of avian and small-mammal response to fire severity and fire surrogate treatments in U.S. fire-prone forests Author: Fontaine, Joseph B., Kennedy, Patricia L. This is the publisher’s final pdf. The published article is copyrighted by Ecological Society of America and can be found at: http://www.esa.org/. Title: Meta-analysis of avian and small-mammal response to fire severity and fire surrogate treatments in U.S. fire-prone forests Author: Fontaine, Joseph B., Kennedy, Patricia L. This is the publisher’s final pdf. The published article is copyrighted by Ecological Society of America and can be found at: http://www.esa.org/. Close

• 7. [Article] Four centuries of soil carbon and nitrogen change after severe fire in a Western Cascades forest landscape

  Fire is a major disturbance process in many forests. Long-term studies of the biogeochemical effects of fires, especially on soils, are very rare. Consequently, long-term effects of fire on soils are often ...

  Citation × Citation Citation Abstract Copy Title: Four centuries of soil carbon and nitrogen change after severe fire in a Western Cascades forest landscape Author: Giesen, Thomas William Fire is a major disturbance process in many forests. Long-term studies of the biogeochemical effects of fires, especially on soils, are very rare. Consequently, long-term effects of fire on soils are often hypothesized from short-term effects. In a chronosequence study, I studied 24 western Cascades (Oregon) forest stands thought to have been initiated in fire. Twelve of those burned about 150 years ago (“young” sites), and the other 12 burned an average of 550 years ago (“old” sites). I hypothesized that young stands would have less carbon (C) and nitrogen (N) in forest floor and in 0 -10 cm mineral soil than old stands. I found that forest floor N pools of old sites (average = 1,823 kg/ha ± s.e. = 132 kg/ha) were significantly greater than young sites (1,450 ± 98 kg/ha). Similarly, forest floor C pools of old sites (62,980 ± 5,403 kg/ha) were significantly greater than young sites (49,032 ± 2,965 kg/ha). Greater N and C pools in forest floor of old sites resulted from greater forest floor mass in old sites; concentrations of both N and C, and C:N ratios, did not differ significantly by forest age class. In mineral soil, neither concentrations nor pools of N and C differed between young and old sites. Despite overall similarity of C:N ratios in young versus old sites, potential N mineralization rates were twice as high in forest floor of old sites (average = 60 ± 7.3 mg N / g soil) than young sites (26 ± 3.5 mg N / g soil), . Nitrate accounted for only 2% or less of total N mineralized in forest floor samples. In mineral soil, potential net N mineralization did not differ by forest age class. The pattern of high net N mineralization and low nitrification in old forests is consistent with other studies of fire-prone forests, yet contrasts with many studies of forests that lack fire, and suggests that ammonium is not the sole control over nitrification in fire-prone ecosystems. Overall, fire appears to impart a longterm legacy of reduced forest floor N and C pools in this western Oregon Cascades landscape, which suggests that current fire-suppression activities in the region may increase forest floor N and C storage over historical conditions within several centuries. The differences in forest floor and soil N cycling processes that I observed by forest age class raise the further possibility that fire exclusion in these forests may change the relative abundance of soil inorganic N forms to favor ammonium over nitrate. Such changes may have unknown consequences for relative competitive abilities of plant and microbial species that rely preferentially on different N-forms to meet N nutrition requirements. While forest floor N and C pools increase from young to old stands, forest floor and soil N and C pools are not different, or decline, between 450 year old stands and the oldest stands at 800+ years, That, and other, anomalous changes in values from ~450 to 800+ years, suggest possible changes in ecosystem functions, and may indicate that this landscape could be a fruitful study area for examinations of a mature, steady-state ecosystem Title: Four centuries of soil carbon and nitrogen change after severe fire in a Western Cascades forest landscape Author: Giesen, Thomas William Fire is a major disturbance process in many forests. Long-term studies of the biogeochemical effects of fires, especially on soils, are very rare. Consequently, long-term effects of fire on soils are often hypothesized from short-term effects. In a chronosequence study, I studied 24 western Cascades (Oregon) forest stands thought to have been initiated in fire. Twelve of those burned about 150 years ago (“young” sites), and the other 12 burned an average of 550 years ago (“old” sites). I hypothesized that young stands would have less carbon (C) and nitrogen (N) in forest floor and in 0 -10 cm mineral soil than old stands. I found that forest floor N pools of old sites (average = 1,823 kg/ha ± s.e. = 132 kg/ha) were significantly greater than young sites (1,450 ± 98 kg/ha). Similarly, forest floor C pools of old sites (62,980 ± 5,403 kg/ha) were significantly greater than young sites (49,032 ± 2,965 kg/ha). Greater N and C pools in forest floor of old sites resulted from greater forest floor mass in old sites; concentrations of both N and C, and C:N ratios, did not differ significantly by forest age class. In mineral soil, neither concentrations nor pools of N and C differed between young and old sites. Despite overall similarity of C:N ratios in young versus old sites, potential N mineralization rates were twice as high in forest floor of old sites (average = 60 ± 7.3 mg N / g soil) than young sites (26 ± 3.5 mg N / g soil), . Nitrate accounted for only 2% or less of total N mineralized in forest floor samples. In mineral soil, potential net N mineralization did not differ by forest age class. The pattern of high net N mineralization and low nitrification in old forests is consistent with other studies of fire-prone forests, yet contrasts with many studies of forests that lack fire, and suggests that ammonium is not the sole control over nitrification in fire-prone ecosystems. Overall, fire appears to impart a longterm legacy of reduced forest floor N and C pools in this western Oregon Cascades landscape, which suggests that current fire-suppression activities in the region may increase forest floor N and C storage over historical conditions within several centuries. The differences in forest floor and soil N cycling processes that I observed by forest age class raise the further possibility that fire exclusion in these forests may change the relative abundance of soil inorganic N forms to favor ammonium over nitrate. Such changes may have unknown consequences for relative competitive abilities of plant and microbial species that rely preferentially on different N-forms to meet N nutrition requirements. While forest floor N and C pools increase from young to old stands, forest floor and soil N and C pools are not different, or decline, between 450 year old stands and the oldest stands at 800+ years, That, and other, anomalous changes in values from ~450 to 800+ years, suggest possible changes in ecosystem functions, and may indicate that this landscape could be a fruitful study area for examinations of a mature, steady-state ecosystem Close

• 8. [Article] Patterns of crown damage within a large wildfire in the Klamath-Siskiyou bioregion

  The 2002 Biscuit Fire burned through more than 200,000 ha of mixed conifer/ evergreen hardwood forests in southwestern Oregon and northwestern California. The remarkable size of the fire and the diversity ...

  Citation × Citation Citation Abstract Copy Title: Patterns of crown damage within a large wildfire in the Klamath-Siskiyou bioregion Author: Thompson, Jonathan R. The 2002 Biscuit Fire burned through more than 200,000 ha of mixed conifer/ evergreen hardwood forests in southwestern Oregon and northwestern California. The remarkable size of the fire and the diversity of conditions through which it burned provided an opportunity to analyze the correlates of burn severity across vegetation types and disturbance histories and to describe the weather, topographical, and fuel conditions that gave rise to the mosaic of crown damage. In chapter two, I focused on a region that had burned previously by the 1987 Silver Fire then was subject, in part, to salvage-logging and conifer planting before being reburned by the Biscuit Fire. I used the Landsat-based differenced normalized burn ratio (dNBR) to quantify severity in both fires and took a hypothesis-testing approach to answering two questions: First, was severity in the Biscuit Fire associated with severity in the Silver Fire in unmanaged areas? And second, did areas that were salvaged-logged and planted with conifers after the Silver Fire burn more or less severely in the Biscuit Fire than comparable unmanaged areas? I found that areas that burned severely in 1987 tended to re-burn at high severity in 2002, after controlling for the influence of several topographical and biophysical covariates. Areas unaffected by the initial fire tended to burn at the lowest severities in 2002. In addition, areas that were salvage-logged and planted after the initial fire burned more severely than comparable unmanaged areas, suggesting that post-fire logging and planting did not reduce future fire severity as had been suggested by some. In chapter three, I again focused on the twice-burned landscape, but this time I used a temporal sequence of digital aerial photography plots (6.25 ha) to measure changes in shrub-stratum, hardwood, and conifer cover. I estimated the strength and nature of relationships between crown damage and several fuel, topographical, weather, and management variables. Median crown damage, including damage to the shrub-stratum, on unmanaged plots was 63% after the Biscuit Fire and was most strongly related to damage in the Silver Fire. Plots that burned severely in the Silver Fire and had succeeded to a mix of shrubs and tree regeneration experienced high levels of Biscuit Fire damage. Plots dominated by large conifer cover after the Silver Fire had the lowest levels of Biscuit Fire canopy damage. Median crown damage was 39% for conifer cover and 85% for hardwood cover, and was most strongly related to daily average temperature and "burn period," an index of fire weather and fire suppression effort. Damage in the tree-stratum was largely independent of Silver Fire severity. Plots that had experienced stand replacing fire in 1987 and then were logged and planted with conifers had median crown damage of 100%. Plots that experienced a stand replacing fire but were unmanaged had median crown damage of 95%. The managed areas were at higher topographical positions and had greater total pre-fire cover, which may explain the small difference. These results suggest that in productive, fire-prone landscapes, the patch mosaic of young regenerating forest created by mixed-severity fire can structure the severity pattern of future wildfires occurring at short intervals and support the previous studies findings that post-fire logging and planting did not reduce fire severity. In Chapter four, I expanded my focus to include the entire region burned by the Biscuit Fire and again used digital aerial photos taken before and after the fire to interpret patterns of crown damage and relate them to several fuel, topographical, weather, and management variables. Ninety-eight percent of plots experienced some level of crown damage, but only 10% experienced complete crown damage. The median level of crown damage on unmanaged plots was 74%. Median conifer damage was 52%. The most important predictors of total crown damage were the percentage of pre-fire shrub-stratum vegetation cover and average daily temperature. The most important predictors of conifer damage were average daily temperature and burn period. Increasing levels of shrub-stratum cover were associated with increasing levels of conifer damage and hardwood damage. Large conifers had 32% median crown damage while small conifers had 62% median crown damage. Owing largely to widespread shrub-stratum cover, low-productivity ultramafic soils had 92% median crown damage compared to 59% on non-ultramafic sites. Patterns of damage were similar within the area that burned previously in the 1987 Silver Fire and edaphically comparable areas without a recently history of fire. Median crown damage in conifer plantations was 89% and plantation age was, by far, the most important predictor of the level of damage. Plantations under 20 years old experienced the highest rates of damage. I conclude that weather and vegetation conditions--not topography--were the primary determinants of Biscuit Fire crown damage. These findings suggest that in productive fire-prone ecosystems, fuel treatments that open tree canopies and stimulate shrub-stratum development may be counterproductive. Title: Patterns of crown damage within a large wildfire in the Klamath-Siskiyou bioregion Author: Thompson, Jonathan R. The 2002 Biscuit Fire burned through more than 200,000 ha of mixed conifer/ evergreen hardwood forests in southwestern Oregon and northwestern California. The remarkable size of the fire and the diversity of conditions through which it burned provided an opportunity to analyze the correlates of burn severity across vegetation types and disturbance histories and to describe the weather, topographical, and fuel conditions that gave rise to the mosaic of crown damage. In chapter two, I focused on a region that had burned previously by the 1987 Silver Fire then was subject, in part, to salvage-logging and conifer planting before being reburned by the Biscuit Fire. I used the Landsat-based differenced normalized burn ratio (dNBR) to quantify severity in both fires and took a hypothesis-testing approach to answering two questions: First, was severity in the Biscuit Fire associated with severity in the Silver Fire in unmanaged areas? And second, did areas that were salvaged-logged and planted with conifers after the Silver Fire burn more or less severely in the Biscuit Fire than comparable unmanaged areas? I found that areas that burned severely in 1987 tended to re-burn at high severity in 2002, after controlling for the influence of several topographical and biophysical covariates. Areas unaffected by the initial fire tended to burn at the lowest severities in 2002. In addition, areas that were salvage-logged and planted after the initial fire burned more severely than comparable unmanaged areas, suggesting that post-fire logging and planting did not reduce future fire severity as had been suggested by some. In chapter three, I again focused on the twice-burned landscape, but this time I used a temporal sequence of digital aerial photography plots (6.25 ha) to measure changes in shrub-stratum, hardwood, and conifer cover. I estimated the strength and nature of relationships between crown damage and several fuel, topographical, weather, and management variables. Median crown damage, including damage to the shrub-stratum, on unmanaged plots was 63% after the Biscuit Fire and was most strongly related to damage in the Silver Fire. Plots that burned severely in the Silver Fire and had succeeded to a mix of shrubs and tree regeneration experienced high levels of Biscuit Fire damage. Plots dominated by large conifer cover after the Silver Fire had the lowest levels of Biscuit Fire canopy damage. Median crown damage was 39% for conifer cover and 85% for hardwood cover, and was most strongly related to daily average temperature and "burn period," an index of fire weather and fire suppression effort. Damage in the tree-stratum was largely independent of Silver Fire severity. Plots that had experienced stand replacing fire in 1987 and then were logged and planted with conifers had median crown damage of 100%. Plots that experienced a stand replacing fire but were unmanaged had median crown damage of 95%. The managed areas were at higher topographical positions and had greater total pre-fire cover, which may explain the small difference. These results suggest that in productive, fire-prone landscapes, the patch mosaic of young regenerating forest created by mixed-severity fire can structure the severity pattern of future wildfires occurring at short intervals and support the previous studies findings that post-fire logging and planting did not reduce fire severity. In Chapter four, I expanded my focus to include the entire region burned by the Biscuit Fire and again used digital aerial photos taken before and after the fire to interpret patterns of crown damage and relate them to several fuel, topographical, weather, and management variables. Ninety-eight percent of plots experienced some level of crown damage, but only 10% experienced complete crown damage. The median level of crown damage on unmanaged plots was 74%. Median conifer damage was 52%. The most important predictors of total crown damage were the percentage of pre-fire shrub-stratum vegetation cover and average daily temperature. The most important predictors of conifer damage were average daily temperature and burn period. Increasing levels of shrub-stratum cover were associated with increasing levels of conifer damage and hardwood damage. Large conifers had 32% median crown damage while small conifers had 62% median crown damage. Owing largely to widespread shrub-stratum cover, low-productivity ultramafic soils had 92% median crown damage compared to 59% on non-ultramafic sites. Patterns of damage were similar within the area that burned previously in the 1987 Silver Fire and edaphically comparable areas without a recently history of fire. Median crown damage in conifer plantations was 89% and plantation age was, by far, the most important predictor of the level of damage. Plantations under 20 years old experienced the highest rates of damage. I conclude that weather and vegetation conditions--not topography--were the primary determinants of Biscuit Fire crown damage. These findings suggest that in productive fire-prone ecosystems, fuel treatments that open tree canopies and stimulate shrub-stratum development may be counterproductive. Close

• 9. [Article] Managing fire-prone forests in the western United States

  The management of fire-prone forests is one of the most controversial natural resource issues in the US today, particularly in the west of the country. Although vegetation and wildlife in these forests ...

  Citation × Citation Citation Abstract Copy Title: Managing fire-prone forests in the western United States Author: Schoennagel, Tania, Baker, William L., Moyle, Peter B., Noss, Reed F., Franklin, Jerry F. The management of fire-prone forests is one of the most controversial natural resource issues in the US today, particularly in the west of the country. Although vegetation and wildlife in these forests are adapted to fire, the historical range of fire frequency and severity was huge. When fire regimes are altered by human activity, major effects on biodiversity and ecosystem function are unavoidable. We review the ecological science relevant to developing and implementing fire and fuel management policies for forests before, during, and after wildfires. Fire exclusion led to major deviations from historical variability in many dry, low-elevation forests, but not in other forests, such as those characterized by high severity fires recurring at intervals longer than the period of active fire exclusion. Restoration and management of fire-prone forests should be precautionary, allow or mimic natural fire regimes as much as possible, and generally avoid intensive practices such as post-fire logging and planting. Title: Managing fire-prone forests in the western United States Author: Schoennagel, Tania, Baker, William L., Moyle, Peter B., Noss, Reed F., Franklin, Jerry F. The management of fire-prone forests is one of the most controversial natural resource issues in the US today, particularly in the west of the country. Although vegetation and wildlife in these forests are adapted to fire, the historical range of fire frequency and severity was huge. When fire regimes are altered by human activity, major effects on biodiversity and ecosystem function are unavoidable. We review the ecological science relevant to developing and implementing fire and fuel management policies for forests before, during, and after wildfires. Fire exclusion led to major deviations from historical variability in many dry, low-elevation forests, but not in other forests, such as those characterized by high severity fires recurring at intervals longer than the period of active fire exclusion. Restoration and management of fire-prone forests should be precautionary, allow or mimic natural fire regimes as much as possible, and generally avoid intensive practices such as post-fire logging and planting. Close

• 10. [Article] Social science research related to wildfire management: an overview of recent findings and future research needs

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by CSIRO Publishing ...

  Citation × Citation Citation Abstract Copy Title: Social science research related to wildfire management: an overview of recent findings and future research needs Author: Stidham, Melanie, Shindler, Bruce, Toman, Eric, McCaffrey, Sarah To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by CSIRO Publishing and can be found at: http://www.publish.csiro.au/. Title: Social science research related to wildfire management: an overview of recent findings and future research needs Author: Stidham, Melanie, Shindler, Bruce, Toman, Eric, McCaffrey, Sarah To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by CSIRO Publishing and can be found at: http://www.publish.csiro.au/. Close

• 11. [Article] Disturbance and dynamics of riparian forests in southwestern Oregon

  Fire exclusion has been associated with structural and compositional changes in many upland forests of the western United States, but little is known about the impacts on riparian forests, portions of ...

  Citation × Citation Citation Abstract Copy Title: Disturbance and dynamics of riparian forests in southwestern Oregon Author: Messier, Michael S. Fire exclusion has been associated with structural and compositional changes in many upland forests of the western United States, but little is known about the impacts on riparian forests, portions of the landscape protected for habitat and water quality. For this study, I characterized the historic disturbance and tree recruitment processes of riparian forests in southwestern Oregon. I identified the ways in which riparian forest structure and composition have changed over the past 100 to 150 years, with a particular focus on the effects of fire exclusion. I used dendro-ecological methods to analyze tree ring data collected in riparian forest stands of two vegetation types in the Rogue River basin of southwestern Oregon: the mesic 'Mixed Conifer' zone (Pinus-Pseudotsuga-Calocedrus-Abies) and the more xeric 'Interior Valley' zone (Pinus-Quercus-Pseudotsuga). My results suggest riparian forests in both vegetation zones developed with frequent disturbance by fire and that, since fire has been excluded, these forests have entered a new successional trajectory. In the Mixed Conifer zone, tree recruitment in the pre-settlement period appears to have been driven by the interaction between climatic fluctuations and mixed-severity fires, which historically maintained multi-aged stands of shade-intolerant species. Patches of highseverity fire within the mixed-severity matrix created large canopy gaps (>30 m in diameter) in which new cohorts of Douglas-fir (Pseudotsuga menziesii) could establish within existing stands and perpetuate Douglas-fir overstory dominance. Tree recruitment appears to have been closely linked Since fire exclusion became effective, there has been an increase in tree density and a shift toward the establishment of white fir (Abies concolor), a fire-sensitive, shade-tolerant species. In the Interior Valley zone, riparian forests were most likely shaped by a low-severity fire regime. Frequent fires likely killed most tree seedlings and maintained open savannas or woodlands with shade-intolerant hardwoods and scattered, open-grown conifers. Fire exclusion in the Interior Valley zone has resulted in exceptionally high survival rates in Douglas-fir recruited during the late 19th and early 20th centuries. This led to the establishment of a closed-canopy conifer forest with fewer shade-intolerant hardwoods, which are an important source of food and habitat for wildlife. My findings suggest future management guidelines for riparian forests in fire-prone forests of the Pacific Northwest should consider the substantial and potentially undesirable ecological effects of the current hands-off management policy in riparian forests. Future proposals to attempt restoration of pre-settlement forest structure and composition in upland forests should also consider including restoration treatments within adjoining riparian forests. Title: Disturbance and dynamics of riparian forests in southwestern Oregon Author: Messier, Michael S. Fire exclusion has been associated with structural and compositional changes in many upland forests of the western United States, but little is known about the impacts on riparian forests, portions of the landscape protected for habitat and water quality. For this study, I characterized the historic disturbance and tree recruitment processes of riparian forests in southwestern Oregon. I identified the ways in which riparian forest structure and composition have changed over the past 100 to 150 years, with a particular focus on the effects of fire exclusion. I used dendro-ecological methods to analyze tree ring data collected in riparian forest stands of two vegetation types in the Rogue River basin of southwestern Oregon: the mesic 'Mixed Conifer' zone (Pinus-Pseudotsuga-Calocedrus-Abies) and the more xeric 'Interior Valley' zone (Pinus-Quercus-Pseudotsuga). My results suggest riparian forests in both vegetation zones developed with frequent disturbance by fire and that, since fire has been excluded, these forests have entered a new successional trajectory. In the Mixed Conifer zone, tree recruitment in the pre-settlement period appears to have been driven by the interaction between climatic fluctuations and mixed-severity fires, which historically maintained multi-aged stands of shade-intolerant species. Patches of highseverity fire within the mixed-severity matrix created large canopy gaps (>30 m in diameter) in which new cohorts of Douglas-fir (Pseudotsuga menziesii) could establish within existing stands and perpetuate Douglas-fir overstory dominance. Tree recruitment appears to have been closely linked Since fire exclusion became effective, there has been an increase in tree density and a shift toward the establishment of white fir (Abies concolor), a fire-sensitive, shade-tolerant species. In the Interior Valley zone, riparian forests were most likely shaped by a low-severity fire regime. Frequent fires likely killed most tree seedlings and maintained open savannas or woodlands with shade-intolerant hardwoods and scattered, open-grown conifers. Fire exclusion in the Interior Valley zone has resulted in exceptionally high survival rates in Douglas-fir recruited during the late 19th and early 20th centuries. This led to the establishment of a closed-canopy conifer forest with fewer shade-intolerant hardwoods, which are an important source of food and habitat for wildlife. My findings suggest future management guidelines for riparian forests in fire-prone forests of the Pacific Northwest should consider the substantial and potentially undesirable ecological effects of the current hands-off management policy in riparian forests. Future proposals to attempt restoration of pre-settlement forest structure and composition in upland forests should also consider including restoration treatments within adjoining riparian forests. Close

• 12. [Article] Building on Two Decades of Ecosystem Management and Biodiversity Conservation under the Northwest Forest Plan, USA

  Correction: We discovered two typos and a change in a sentence needed in our published manuscript. Regarding the typos: timber estimates in Section 2 of the NWFP’s Long-Term Objectives should have been ...

  Citation × Citation Citation Abstract Copy Title: Building on Two Decades of Ecosystem Management and Biodiversity Conservation under the Northwest Forest Plan, USA Author: DellaSala, Dominick A., Baker, Rowan, Heiken, Doug, Nelson, S. Kim, et al. Correction: We discovered two typos and a change in a sentence needed in our published manuscript. Regarding the typos: timber estimates in Section 2 of the NWFP’s Long-Term Objectives should have been 2.34 million cubic meters annually instead of 234 million cubic meters annually and ~1.78 million cubic meters instead of 178 million cubic meters annually. The statement regarding murrelet populations—“Trends were downward (but not significant) in other NWFP states” should be deleted in this paper [1]. The authors would like to apologize for any inconvenience caused to the readers by these changes. Title: Building on Two Decades of Ecosystem Management and Biodiversity Conservation under the Northwest Forest Plan, USA Author: DellaSala, Dominick A., Baker, Rowan, Heiken, Doug, Nelson, S. Kim, et al. Correction: We discovered two typos and a change in a sentence needed in our published manuscript. Regarding the typos: timber estimates in Section 2 of the NWFP’s Long-Term Objectives should have been 2.34 million cubic meters annually instead of 234 million cubic meters annually and ~1.78 million cubic meters instead of 178 million cubic meters annually. The statement regarding murrelet populations—“Trends were downward (but not significant) in other NWFP states” should be deleted in this paper [1]. The authors would like to apologize for any inconvenience caused to the readers by these changes. Close

• 13. [Article] Fuel moisture influences on fire-altered carbon in masticated fuels: An experimental study

  This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://www.agu.org/journals/jgr/.

  Citation × Citation Citation Abstract Copy Title: Fuel moisture influences on fire-altered carbon in masticated fuels: An experimental study Author: Smith, Alistair M. S., Higuera, Philip E., Ottmar, Roger D., Tinkham, Wade T., Hatten, Jeffery A., Hudak, Andrew T., Brewer, Nolan W. This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://www.agu.org/journals/jgr/. Title: Fuel moisture influences on fire-altered carbon in masticated fuels: An experimental study Author: Smith, Alistair M. S., Higuera, Philip E., Ottmar, Roger D., Tinkham, Wade T., Hatten, Jeffery A., Hudak, Andrew T., Brewer, Nolan W. This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://www.agu.org/journals/jgr/. Close

• 14. [Article] Forest wildfire, fuel reduction treatments, and landscape carbon stocks: A sensitivity analysis

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier ...

  Citation × Citation Citation Abstract Copy Title: Forest wildfire, fuel reduction treatments, and landscape carbon stocks: A sensitivity analysis Author: Ager, Alan A., Campbell, John L. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Title: Forest wildfire, fuel reduction treatments, and landscape carbon stocks: A sensitivity analysis Author: Ager, Alan A., Campbell, John L. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Close

• 15. [Article] Comparative hazard assessment for protected species in a fire-prone landscape

  This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/forest-ecology-...

  Citation × Citation Citation Abstract Copy Title: Comparative hazard assessment for protected species in a fire-prone landscape Author: Mealey, Stephen P., Roloff, Gary J., Bailey, John D. This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/forest-ecology-and-management/. Title: Comparative hazard assessment for protected species in a fire-prone landscape Author: Mealey, Stephen P., Roloff, Gary J., Bailey, John D. This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/forest-ecology-and-management/. Close

• 16. [Article] Examining fire-prone forest landscapes as coupled human and natural systems

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the author(s) ...

  Citation × Citation Citation Abstract Copy Title: Examining fire-prone forest landscapes as coupled human and natural systems Author: Bolte, John, White, Eric M., Jacobs, Derric, Shindler, Bruce, Spies, Thomas A., Platt, Emily, Bailey, John, Kline, Jeffrey D., et al., Olsen, Christine S., Hammer, Roger To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Resilience Alliance. The published article can be found at: http://www.ecologyandsociety.org/. Title: Examining fire-prone forest landscapes as coupled human and natural systems Author: Bolte, John, White, Eric M., Jacobs, Derric, Shindler, Bruce, Spies, Thomas A., Platt, Emily, Bailey, John, Kline, Jeffrey D., et al., Olsen, Christine S., Hammer, Roger To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Resilience Alliance. The published article can be found at: http://www.ecologyandsociety.org/. Close

• 17. [Article] Fish Capture and Culture in Agro-Ecosystems: A New Concept for Old Practice?

  No poster available.

  Citation × Citation Citation Abstract Copy Title: Fish Capture and Culture in Agro-Ecosystems: A New Concept for Old Practice? Author: Nguyen-Khoa, Sophie, Van Brakel, Martin No poster available. Title: Fish Capture and Culture in Agro-Ecosystems: A New Concept for Old Practice? Author: Nguyen-Khoa, Sophie, Van Brakel, Martin No poster available. Close

• 18. [Article] A land manager's guide for creating fire-resistant forests

  Published September 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog

  Citation × Citation Citation Abstract Copy Title: A land manager's guide for creating fire-resistant forests Author: Fitzgerald, Stephen Arthur, Bennett, Max, 1963-, Oregon State University. Extension Service Published September 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: A land manager's guide for creating fire-resistant forests Author: Fitzgerald, Stephen Arthur, Bennett, Max, 1963-, Oregon State University. Extension Service Published September 2013. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 19. [Article] CEO 1 ; An Illustrated Guide to Fire in Central Oregon Forests

  This pictorial guide is primarily intended to serve as a backdrop for field tours of central Oregon that involve topics surrounding wildland fire. It also is designed to provide an overview of the role ...

  Citation × Citation Citation Abstract Copy Title: CEO 1 ; An Illustrated Guide to Fire in Central Oregon Forests Author: Tappeiner, J. C. (John C.), Eckert, Bradley E., Walstad, John D., Oregon State University. Forest Research Laboratory This pictorial guide is primarily intended to serve as a backdrop for field tours of central Oregon that involve topics surrounding wildland fire. It also is designed to provide an overview of the role of fire in the major ecosystems characteristic of this region. Topics covered include fire history, fire regimes, current fire conditions, fire behavior, fire threats to natural resources, fuel treatments, interactions with the public, and future challenges and management options. A list of key references and glossary are also included. Title: CEO 1 ; An Illustrated Guide to Fire in Central Oregon Forests Author: Tappeiner, J. C. (John C.), Eckert, Bradley E., Walstad, John D., Oregon State University. Forest Research Laboratory This pictorial guide is primarily intended to serve as a backdrop for field tours of central Oregon that involve topics surrounding wildland fire. It also is designed to provide an overview of the role of fire in the major ecosystems characteristic of this region. Topics covered include fire history, fire regimes, current fire conditions, fire behavior, fire threats to natural resources, fuel treatments, interactions with the public, and future challenges and management options. A list of key references and glossary are also included. Close

• 20. [Article] Observations and assessment of forest carbon dynamics following disturbance in North America

  This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://www.agu.org/journals/jgr/. To the best of our knowledge, one or more ...

  Citation × Citation Citation Abstract Copy Title: Observations and assessment of forest carbon dynamics following disturbance in North America Author: Pfeifer, E. M., Kasischke, E. S., Houghton, R. A., McNulty, S., Law, B. E., Goetz, S. J., Harmon, M., Huang, C., Meddens, A. J. H., Mildrexler, D., Bond-Lamberty, B., O'Halloran, T., Hicke, J. A. This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://www.agu.org/journals/jgr/. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Title: Observations and assessment of forest carbon dynamics following disturbance in North America Author: Pfeifer, E. M., Kasischke, E. S., Houghton, R. A., McNulty, S., Law, B. E., Goetz, S. J., Harmon, M., Huang, C., Meddens, A. J. H., Mildrexler, D., Bond-Lamberty, B., O'Halloran, T., Hicke, J. A. This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://www.agu.org/journals/jgr/. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Close

• 21. [Article] Data from: Network analysis of wildfire transmission and implications for risk governance

  [Suggested citation: Ager, AA; Evers, CR; Day, MA; Preisler, HK; Barros, AM; Nielsen-Pincus, M (2017): Data from: Network analysis of wildfire transmission and implications for risk governance. OSU Libraries. ...

  Citation × Citation Citation Abstract Copy Title: Data from: Network analysis of wildfire transmission and implications for risk governance Author: Barros, AM, Preisler, HK, Ager, AA, Nielsen-Pincus, M, Day, MA, Evers, CR [Suggested citation: Ager, AA; Evers, CR; Day, MA; Preisler, HK; Barros, AM; Nielsen-Pincus, M (2017): Data from: Network analysis of wildfire transmission and implications for risk governance. OSU Libraries. Dataset. https://doi.org/10.7267/N9G15XS6] Title: Data from: Network analysis of wildfire transmission and implications for risk governance Author: Barros, AM, Preisler, HK, Ager, AA, Nielsen-Pincus, M, Day, MA, Evers, CR [Suggested citation: Ager, AA; Evers, CR; Day, MA; Preisler, HK; Barros, AM; Nielsen-Pincus, M (2017): Data from: Network analysis of wildfire transmission and implications for risk governance. OSU Libraries. Dataset. https://doi.org/10.7267/N9G15XS6] Close

• 22. [Article] Essays on the interactions between land use, natural amenity and wildfire risk

  It is essential to study the relationship between environmental features and human land-use activities that can provide a better understanding of human-environment interactions. In a response, this dissertation ...

  Citation × Citation Citation Abstract Copy Title: Essays on the interactions between land use, natural amenity and wildfire risk Author: Xu, Wenchao It is essential to study the relationship between environmental features and human land-use activities that can provide a better understanding of human-environment interactions. In a response, this dissertation addresses the human-environment issues from different perspectives in three essays. The first essay conducts an integrated analysis to investigate the impacts of human activities and environmental features on wildfire occurrence at the Wildland-Urban Interface in a changing climate. We focus on the impacts of land use changes as measured by their density, connectivity, and mix. The conceptual model builds on a theoretical framework developed by Woodward (1987) and Neilson (1995) that characterizes the functioning mechanism of ecosystems. The empirical models identify the key factors that influence wildfires. Hypotheses are tested to demonstrate the spatial heterogeneity of human land-use impacts on wildfires. Results can inform the design of policies that aim to identify community vulnerabilities, reduce wildfire uncertainties, strengthen firewise community development, and inform future land-use decision making in response to wildfire threats. The second essay analyzes the impacts of wildfire risk on urban development. It builds on and expands the monocentric-city framework developed by Wu (2006) and Wu (2010) by introducing wildfire risk into this model. We calibrate the model and examine the urban spatial profiles changes under different assumptions of wildfire risks and natural amenities. We find that wildfire risk can take on various aspects of urban spatial profiles at a much broad scale that go beyond the fire-prone areas and affects both households and public decision sectors. Even without inconsistency in fire-zone designation policy, over-development can occur in fire-hazardous area. The third essay models the role of amenity in interregional migration and spatial distribution of economic activities. Extending the new economic geography model of Helpman (1998) by including locational amenities, we present a multi-market equilibrium framework that includes consumption, production, and trade. Results suggest that the effects of amenities are significantly affected by household preferences, trade barriers, and other regional economic characteristics. This study contributes to the amenity-driven migration literatures and informs the debate about the effect of amenities on interregional migrations and regional economic development. Title: Essays on the interactions between land use, natural amenity and wildfire risk Author: Xu, Wenchao It is essential to study the relationship between environmental features and human land-use activities that can provide a better understanding of human-environment interactions. In a response, this dissertation addresses the human-environment issues from different perspectives in three essays. The first essay conducts an integrated analysis to investigate the impacts of human activities and environmental features on wildfire occurrence at the Wildland-Urban Interface in a changing climate. We focus on the impacts of land use changes as measured by their density, connectivity, and mix. The conceptual model builds on a theoretical framework developed by Woodward (1987) and Neilson (1995) that characterizes the functioning mechanism of ecosystems. The empirical models identify the key factors that influence wildfires. Hypotheses are tested to demonstrate the spatial heterogeneity of human land-use impacts on wildfires. Results can inform the design of policies that aim to identify community vulnerabilities, reduce wildfire uncertainties, strengthen firewise community development, and inform future land-use decision making in response to wildfire threats. The second essay analyzes the impacts of wildfire risk on urban development. It builds on and expands the monocentric-city framework developed by Wu (2006) and Wu (2010) by introducing wildfire risk into this model. We calibrate the model and examine the urban spatial profiles changes under different assumptions of wildfire risks and natural amenities. We find that wildfire risk can take on various aspects of urban spatial profiles at a much broad scale that go beyond the fire-prone areas and affects both households and public decision sectors. Even without inconsistency in fire-zone designation policy, over-development can occur in fire-hazardous area. The third essay models the role of amenity in interregional migration and spatial distribution of economic activities. Extending the new economic geography model of Helpman (1998) by including locational amenities, we present a multi-market equilibrium framework that includes consumption, production, and trade. Results suggest that the effects of amenities are significantly affected by household preferences, trade barriers, and other regional economic characteristics. This study contributes to the amenity-driven migration literatures and informs the debate about the effect of amenities on interregional migrations and regional economic development. Close

• 23. [Article] Wildland fire in ecosystems : effects of fire on fauna

  Fires affect animals mainly through effects on their habitat. Fires often cause short-term increases in wildlife foods that contribute to increases in populations of some animals. These increases are moderated ...

  Citation × Citation Citation Abstract Copy Title: Wildland fire in ecosystems : effects of fire on fauna Author: Schreiner, David Scott, Smith, Jane Kapler, Telfer, Edmund S., Huff, Mark H., Lyon, L. Jack, Hooper, Robert G. Fires affect animals mainly through effects on their habitat. Fires often cause short-term increases in wildlife foods that contribute to increases in populations of some animals. These increases are moderated by the animals’ ability to thrive in the altered, often simplified, structure of the postfire environment. The extent of fire effects on animal communities generally depends on the extent of change in habitat structure and species composition caused by fire. Stand-replacement fires usually cause greater changes in the faunal communities of forests than in those of grasslands. Within forests, standreplacement fires usually alter the animal community more dramatically than understory fires. Animal species are adapted to survive the pattern of fire frequency, season, size, severity, and uniformity that characterized their habitat in presettlement times. When fire frequency increases or decreases substantially or fire severity changes from presettlement patterns, habitat for many animal species declines. Title: Wildland fire in ecosystems : effects of fire on fauna Author: Schreiner, David Scott, Smith, Jane Kapler, Telfer, Edmund S., Huff, Mark H., Lyon, L. Jack, Hooper, Robert G. Fires affect animals mainly through effects on their habitat. Fires often cause short-term increases in wildlife foods that contribute to increases in populations of some animals. These increases are moderated by the animals’ ability to thrive in the altered, often simplified, structure of the postfire environment. The extent of fire effects on animal communities generally depends on the extent of change in habitat structure and species composition caused by fire. Stand-replacement fires usually cause greater changes in the faunal communities of forests than in those of grasslands. Within forests, standreplacement fires usually alter the animal community more dramatically than understory fires. Animal species are adapted to survive the pattern of fire frequency, season, size, severity, and uniformity that characterized their habitat in presettlement times. When fire frequency increases or decreases substantially or fire severity changes from presettlement patterns, habitat for many animal species declines. Close

• 24. [Article] The Schultz Fire : an interdisciplinary perspective on its history, management, and ecological effects

  This thesis examines the Schultz Fire as a case study to explain the complex history of fire suppression management in America’s forests, and to gain further understanding of how management practices have ...

  Citation × Citation Citation Abstract Copy Title: The Schultz Fire : an interdisciplinary perspective on its history, management, and ecological effects Author: Ranseen, Susanne N. This thesis examines the Schultz Fire as a case study to explain the complex history of fire suppression management in America’s forests, and to gain further understanding of how management practices have affected the increase in fire severity levels and how forests respond to such a disturbance. The thesis objectives were: (1) to analyze the causes of the fire severity of the Schultz Fire, especially: topography, fuels, or weather; (2); to examine the possible correlation between fire severity and tree density; (3) to investigate whether post-fire species richness was related to fire severity two years after the Schultz Fire; (4) to investigate whether post-fire plant species richness, plant cover, and tree regeneration was related to fire severity two years after the Schultz Fire; and (5) to interlink and convey how these factors relate to the history of fire management and policy and public perception. The history of fire related policy and management has significantly changed the dynamics of America's national parks and forests. Understanding the larger context of this history, both of national fire management and of the effects of language and perception on policy and public reaction, is part of understanding the Schultz Fire as a whole. Based on modeling, high winds combined with the presence of high surface fuel load were the main causes of the Schultz Fire's high fire severity levels. As fire severity increased there was a statistically significant increase in species richness. Severity level had little variation on percentage of cover by plants. No statistically significant relationship between tree density and fire severity levels was found. These findings underline the need for fuel treatments in southwest Ponderosa Pine forests, and effective cooperation between communities, managers, and ecologists. The Schultz Fire serves as an example in understanding the intricacies of how history affects the present and future of fire management. How fire has been managed and portrayed in the past has left an indelible mark on how fire is presently viewed. Without a clear understanding of the history of fire management and the role of fire in the ecology, future policies towards fire will be unable to account for and manage for the diversity of ecosystems and fires effects on those ecosystems across the United States. Title: The Schultz Fire : an interdisciplinary perspective on its history, management, and ecological effects Author: Ranseen, Susanne N. This thesis examines the Schultz Fire as a case study to explain the complex history of fire suppression management in America’s forests, and to gain further understanding of how management practices have affected the increase in fire severity levels and how forests respond to such a disturbance. The thesis objectives were: (1) to analyze the causes of the fire severity of the Schultz Fire, especially: topography, fuels, or weather; (2); to examine the possible correlation between fire severity and tree density; (3) to investigate whether post-fire species richness was related to fire severity two years after the Schultz Fire; (4) to investigate whether post-fire plant species richness, plant cover, and tree regeneration was related to fire severity two years after the Schultz Fire; and (5) to interlink and convey how these factors relate to the history of fire management and policy and public perception. The history of fire related policy and management has significantly changed the dynamics of America's national parks and forests. Understanding the larger context of this history, both of national fire management and of the effects of language and perception on policy and public reaction, is part of understanding the Schultz Fire as a whole. Based on modeling, high winds combined with the presence of high surface fuel load were the main causes of the Schultz Fire's high fire severity levels. As fire severity increased there was a statistically significant increase in species richness. Severity level had little variation on percentage of cover by plants. No statistically significant relationship between tree density and fire severity levels was found. These findings underline the need for fuel treatments in southwest Ponderosa Pine forests, and effective cooperation between communities, managers, and ecologists. The Schultz Fire serves as an example in understanding the intricacies of how history affects the present and future of fire management. How fire has been managed and portrayed in the past has left an indelible mark on how fire is presently viewed. Without a clear understanding of the history of fire management and the role of fire in the ecology, future policies towards fire will be unable to account for and manage for the diversity of ecosystems and fires effects on those ecosystems across the United States. Close

• 25. [Article] Historical fire regime in the Little River watershed, southwestern Oregon

  Disturbances are a prevalent and important part of ecosystems. Many landscape patterns that we find today were created, maintained, and changed by natural disturbance regimes. This is especially true for ...

  Citation × Citation Citation Abstract Copy Title: Historical fire regime in the Little River watershed, southwestern Oregon Author: Van Norman, Kelli J. Disturbances are a prevalent and important part of ecosystems. Many landscape patterns that we find today were created, maintained, and changed by natural disturbance regimes. This is especially true for fire, which has historically been a common, natural disturbance in the western U.S forests and grasslands and many other parts of the globe. I reconstructed fire history and interpreted fire regime in 117 clearcuts distributed throughout a 45,000 ha study area within the Little River watershed, an Adaptive Management Area in southwestern Oregon. Tree rings were counted on over 3,000 stumps and provided a 683-year record of fire. The study area fire regime can be characterized by its variability. The composite median fire return interval for the study area was approximately 123 years. Fire extents were not estimated, but historical fires tended to be relatively small, usually occurring within less than 2.5 km. Low and moderate severity surface fires appeared to have been more common than stand-replacement fires indicating a moderate severity fire regime with much spatial variability in severity. The fire regime has changed temporally and spatially over the fire history record. Five distinct changes in the rate of fire occurrence were identified (1490-1569, 1570- 1844, 1845-1899, 1900-1925, and 1926-1996) and associated with changes in climate and human fire ignition and fire suppression. Fires were dispersed throughout the study area, probably due to dispersed lightning ignitions and small fire extents. As a result, fire frequency was wealdy correlated with topography. However, during the 1845-1899 time period, more fires occurred at low elevations, suggesting an influence of Euro-American settler fire ignitions. Title: Historical fire regime in the Little River watershed, southwestern Oregon Author: Van Norman, Kelli J. Disturbances are a prevalent and important part of ecosystems. Many landscape patterns that we find today were created, maintained, and changed by natural disturbance regimes. This is especially true for fire, which has historically been a common, natural disturbance in the western U.S forests and grasslands and many other parts of the globe. I reconstructed fire history and interpreted fire regime in 117 clearcuts distributed throughout a 45,000 ha study area within the Little River watershed, an Adaptive Management Area in southwestern Oregon. Tree rings were counted on over 3,000 stumps and provided a 683-year record of fire. The study area fire regime can be characterized by its variability. The composite median fire return interval for the study area was approximately 123 years. Fire extents were not estimated, but historical fires tended to be relatively small, usually occurring within less than 2.5 km. Low and moderate severity surface fires appeared to have been more common than stand-replacement fires indicating a moderate severity fire regime with much spatial variability in severity. The fire regime has changed temporally and spatially over the fire history record. Five distinct changes in the rate of fire occurrence were identified (1490-1569, 1570- 1844, 1845-1899, 1900-1925, and 1926-1996) and associated with changes in climate and human fire ignition and fire suppression. Fires were dispersed throughout the study area, probably due to dispersed lightning ignitions and small fire extents. As a result, fire frequency was wealdy correlated with topography. However, during the 1845-1899 time period, more fires occurred at low elevations, suggesting an influence of Euro-American settler fire ignitions. Close

• 26. [Article] Fire exclusion effects on riparian forest dynamics in southwestern Oregon

  This is the authors' peer-reviewed final manuscript. The published version is copyrighted by Elsevier and can be found here: http://www.journals.elsevier.com/forest-ecology-and-management/#description

  Citation × Citation Citation Abstract Copy Title: Fire exclusion effects on riparian forest dynamics in southwestern Oregon Author: Shatford, Jeff P.A., Messier, Michael S., Hibbs, David E. This is the authors' peer-reviewed final manuscript. The published version is copyrighted by Elsevier and can be found here: http://www.journals.elsevier.com/forest-ecology-and-management/#description Title: Fire exclusion effects on riparian forest dynamics in southwestern Oregon Author: Shatford, Jeff P.A., Messier, Michael S., Hibbs, David E. This is the authors' peer-reviewed final manuscript. The published version is copyrighted by Elsevier and can be found here: http://www.journals.elsevier.com/forest-ecology-and-management/#description Close

• 27. [Article] Assessing the effect of a fuel break network to reduce burnt area and wildfire risk transmission

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the International ...

  Citation × Citation Citation Abstract Copy Title: Assessing the effect of a fuel break network to reduce burnt area and wildfire risk transmission Author: Ager, Alan A., Barros, Ana M. G., Oliveira, Tiago M., Fernandes, Paulo M. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the International Association of Wildland Fire and published by CSIRO Publishing. It can be found at: http://www.publish.csiro.au/nid/114.htm Title: Assessing the effect of a fuel break network to reduce burnt area and wildfire risk transmission Author: Ager, Alan A., Barros, Ana M. G., Oliveira, Tiago M., Fernandes, Paulo M. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article is copyrighted by the International Association of Wildland Fire and published by CSIRO Publishing. It can be found at: http://www.publish.csiro.au/nid/114.htm Close

• 28. [Article] Vegetation response to prescribed fire in mountain big sagebrush ecosystems at Lava Beds National Monument, California

  Anthropogenic land use alterations such as livestock grazing and fire suppression have greatly altered sagebrush grasslands of the Great Basin, facilitating invasion of exotic annuals, increases in woody ...

  Citation × Citation Citation Abstract Copy Title: Vegetation response to prescribed fire in mountain big sagebrush ecosystems at Lava Beds National Monument, California Author: Ellsworth, Lisa M. Anthropogenic land use alterations such as livestock grazing and fire suppression have greatly altered sagebrush grasslands of the Great Basin, facilitating invasion of exotic annuals, increases in woody species, and losses of native species. Much of the current research surrounding wildland and prescribed fire in sagebrush dominated ecosystems has focused on a persistent belief that fire in sagebrush systems results in a loss of native flora and a trend toward dominance by exotic annuals. Fire was historically the dominant disturbance throughout the sagebrush steppe and the plant species that comprised these communities possess a variety of adaptations facilitating survival to the fire regime. In order to restore ecosystems, land managers will need to reintroduce natural ecosystem processes, including natural disturbance processes. To describe the response of these plant communities to fire, I examined the plant community response, seedbank response, and reproductive and density responses of three native bunchgrasses (Pseudoroegneria spicata, Achnatherum therberianum, and Elymus elymoides) as well as one native forb (Calochortus macrocarpus) following spring and fall prescribed fires at Lava Beds National Monument. Fires were applied to three Artemisia tridentata ssp. vaseyana (Mountain Big Sagebrush) plant communities with different land use and fire histories. These communities were different in composition ranging from a dominance of exotic annuals to dominance by native grasses, shrubs, and trees. Little is known about how prescribed fire affects the soil seed bank in sagebrush-dominated ecosystems. To address this, we quantified the emergence of Bromus tectorum (cheatgrass) seedlings as well as emergence of seedlings of functional groups (native forbs, bunchgrasses, and shrubs) in a seedbank germination study. At the invasive dominated site (Gillems Camp), we found 91% fewer B. tectorum seedlings germinated in spring burned sites than in controls immediately following spring prescribed burns. However, soils collected one-year following fire had 40% more B. tectorum germinants (8017 germinants/m [superscript 2]) than unburned controls (5132 germinants/m [superscript 2]). Following fall burns at this site there was a similar response, with a 56% immediate reduction in B. tectorum (as compared to unburned control) and a 59% increase in B. tectorum and 58% increase in exotic forb germinants one year following fires. There was an increase in native forb germination following spring burns (94%) and fall burns (45%) at a site dominated by native plants (Fleener Chimneys). Native bunchgrass seed germination declined following spring fire in sites dominated by sagebrush and native understory vegetation (79%), and in sites where Juniperus occidentalis (western juniper) and other woody species dominated (Merrill Caves) (71%). In invasive-dominated sites (Gillems Camp), there was a decrease in B. tectorum cover following both spring (81% decrease) and fall fires (82% decrease), and little native vegetation composition change. Shrub cover, made up predominantly of Chrysothamnus nauseosus, decreased following spring (95% decrease) and fall (93% decrease) fires. At the sagebrush, native understory site (Fleener Chimneys), there was a reduction in native bunchgrass cover (64% decrease), and an increase in native forbs (168% increase) following spring burns, with no changes following fall fires. At the juniper- woody dominated site (Merrill Caves), fire treatments resulted in a decrease in woody plant cover, with no immediate postfire differences seen in the herbaceous plant community. Density of bunchgrass species (Pseudoroegneria spicata, Achnatherum therberianum, Elymus elymoides) did not change following either spring or fall prescribed fire treatments. Fire enhanced flowering was not seen in C. macrocarpus following spring or fall burns at the native or juniper dominated sites. There was increased reproductive effort in native bunchgrass species following fires in all communities studied. Following spring fires at invasive dominated sites, there was a 245% increase in reproductive culms of P. spicata. Following fall fires in native dominated sites, we saw a 974% increase in reproductive culms of P. spicata and a 184% increase in reproductive culms of A. therberianum. Following fall fires at juniper-dominated sites, we saw in an increase in reproductive culms of P. spicata (678% increase), A. thurberianum (356% increase), and Elymus elymoides (209% increase). These results suggest that implementing prescribed fire in order to restore the natural disturbance regime in these fire-adapted ecosystems is beneficial to restoration and preservation of the native biota. Title: Vegetation response to prescribed fire in mountain big sagebrush ecosystems at Lava Beds National Monument, California Author: Ellsworth, Lisa M. Anthropogenic land use alterations such as livestock grazing and fire suppression have greatly altered sagebrush grasslands of the Great Basin, facilitating invasion of exotic annuals, increases in woody species, and losses of native species. Much of the current research surrounding wildland and prescribed fire in sagebrush dominated ecosystems has focused on a persistent belief that fire in sagebrush systems results in a loss of native flora and a trend toward dominance by exotic annuals. Fire was historically the dominant disturbance throughout the sagebrush steppe and the plant species that comprised these communities possess a variety of adaptations facilitating survival to the fire regime. In order to restore ecosystems, land managers will need to reintroduce natural ecosystem processes, including natural disturbance processes. To describe the response of these plant communities to fire, I examined the plant community response, seedbank response, and reproductive and density responses of three native bunchgrasses (Pseudoroegneria spicata, Achnatherum therberianum, and Elymus elymoides) as well as one native forb (Calochortus macrocarpus) following spring and fall prescribed fires at Lava Beds National Monument. Fires were applied to three Artemisia tridentata ssp. vaseyana (Mountain Big Sagebrush) plant communities with different land use and fire histories. These communities were different in composition ranging from a dominance of exotic annuals to dominance by native grasses, shrubs, and trees. Little is known about how prescribed fire affects the soil seed bank in sagebrush-dominated ecosystems. To address this, we quantified the emergence of Bromus tectorum (cheatgrass) seedlings as well as emergence of seedlings of functional groups (native forbs, bunchgrasses, and shrubs) in a seedbank germination study. At the invasive dominated site (Gillems Camp), we found 91% fewer B. tectorum seedlings germinated in spring burned sites than in controls immediately following spring prescribed burns. However, soils collected one-year following fire had 40% more B. tectorum germinants (8017 germinants/m [superscript 2]) than unburned controls (5132 germinants/m [superscript 2]). Following fall burns at this site there was a similar response, with a 56% immediate reduction in B. tectorum (as compared to unburned control) and a 59% increase in B. tectorum and 58% increase in exotic forb germinants one year following fires. There was an increase in native forb germination following spring burns (94%) and fall burns (45%) at a site dominated by native plants (Fleener Chimneys). Native bunchgrass seed germination declined following spring fire in sites dominated by sagebrush and native understory vegetation (79%), and in sites where Juniperus occidentalis (western juniper) and other woody species dominated (Merrill Caves) (71%). In invasive-dominated sites (Gillems Camp), there was a decrease in B. tectorum cover following both spring (81% decrease) and fall fires (82% decrease), and little native vegetation composition change. Shrub cover, made up predominantly of Chrysothamnus nauseosus, decreased following spring (95% decrease) and fall (93% decrease) fires. At the sagebrush, native understory site (Fleener Chimneys), there was a reduction in native bunchgrass cover (64% decrease), and an increase in native forbs (168% increase) following spring burns, with no changes following fall fires. At the juniper- woody dominated site (Merrill Caves), fire treatments resulted in a decrease in woody plant cover, with no immediate postfire differences seen in the herbaceous plant community. Density of bunchgrass species (Pseudoroegneria spicata, Achnatherum therberianum, Elymus elymoides) did not change following either spring or fall prescribed fire treatments. Fire enhanced flowering was not seen in C. macrocarpus following spring or fall burns at the native or juniper dominated sites. There was increased reproductive effort in native bunchgrass species following fires in all communities studied. Following spring fires at invasive dominated sites, there was a 245% increase in reproductive culms of P. spicata. Following fall fires in native dominated sites, we saw a 974% increase in reproductive culms of P. spicata and a 184% increase in reproductive culms of A. therberianum. Following fall fires at juniper-dominated sites, we saw in an increase in reproductive culms of P. spicata (678% increase), A. thurberianum (356% increase), and Elymus elymoides (209% increase). These results suggest that implementing prescribed fire in order to restore the natural disturbance regime in these fire-adapted ecosystems is beneficial to restoration and preservation of the native biota. Close

• 29. [Article] Beyond smoke and mirrors: a synthesis of fire policy and science

  Fire performs many beneficial ecosystem functions in dry forests and rangelands across much of North America. In the last century, however, the role of fire has been dramatically altered by numerous anthropogenic ...

  Citation × Citation Citation Abstract Copy Title: Beyond smoke and mirrors: a synthesis of fire policy and science Author: Deacon Williams, Cindy, Williams, Jack E., Franklin, Jerry F., Dellasala, Dominick A. Fire performs many beneficial ecosystem functions in dry forests and rangelands across much of North America. In the last century, however, the role of fire has been dramatically altered by numerous anthropogenic factors acting as root causes of the current fire crisis, including widespread logging, road building, fire suppression, habitat fragmentation, urban development, livestock grazing, and, more recently, climate change. The intensity and extent of fires in the western United States, specifically, have dramatically increased over the past several decades. Such shifts in fire behavior have triggered sweeping policy changes that were intended to prevent or contain fires but that pose significant risks to the integrity of ecosystems and the role fire historically played in shaping them. Here, we provide a social and ecological context for summarizing this special issue on fires, including general guidelines and principles for managers concerned about balancing the risks of inaction against the risks of action over extensive areas. Fundamental to our understanding of fire is the notion that it is extremely variable, has multiple causes, and requires ecological solutions that are sensitive to spatial scale and context. Therefore, forest managers must recognize that different forest types have different fire regimes and require fundamentally different fire- management policies. Furthermore, to restore or maintain ecological integrity, including the role of fire, treatments need to be tailored to site-specific conditions with an adaptive approach. We provide a conceptual framework for prioritizing fuel treatments and restoration activities in the wildlands-urban intermix versus those in wildland areas farther from human settlement. In general, the science of conservation biology has much to offer in helping to shape wildfire policy direction; however, conservation biologists must become more engaged to better ensure that policy decisions are based on sound science and that ecological risks are incorporated. Title: Beyond smoke and mirrors: a synthesis of fire policy and science Author: Deacon Williams, Cindy, Williams, Jack E., Franklin, Jerry F., Dellasala, Dominick A. Fire performs many beneficial ecosystem functions in dry forests and rangelands across much of North America. In the last century, however, the role of fire has been dramatically altered by numerous anthropogenic factors acting as root causes of the current fire crisis, including widespread logging, road building, fire suppression, habitat fragmentation, urban development, livestock grazing, and, more recently, climate change. The intensity and extent of fires in the western United States, specifically, have dramatically increased over the past several decades. Such shifts in fire behavior have triggered sweeping policy changes that were intended to prevent or contain fires but that pose significant risks to the integrity of ecosystems and the role fire historically played in shaping them. Here, we provide a social and ecological context for summarizing this special issue on fires, including general guidelines and principles for managers concerned about balancing the risks of inaction against the risks of action over extensive areas. Fundamental to our understanding of fire is the notion that it is extremely variable, has multiple causes, and requires ecological solutions that are sensitive to spatial scale and context. Therefore, forest managers must recognize that different forest types have different fire regimes and require fundamentally different fire- management policies. Furthermore, to restore or maintain ecological integrity, including the role of fire, treatments need to be tailored to site-specific conditions with an adaptive approach. We provide a conceptual framework for prioritizing fuel treatments and restoration activities in the wildlands-urban intermix versus those in wildland areas farther from human settlement. In general, the science of conservation biology has much to offer in helping to shape wildfire policy direction; however, conservation biologists must become more engaged to better ensure that policy decisions are based on sound science and that ecological risks are incorporated. Close

• 30. [Article] Fire effects on vegetation diversity, structure, and successional dynamics in shrub-steppe and mixed conifer environments of the Hells Canyon, Idaho

  The effects of fire severity on post-fire succession and shrub demography were quantified in shrub-steppe grasslands and subalpine forests in the Hells Canyon of the Payette National Forest, Idaho. Following ...

  Citation × Citation Citation Abstract Copy Title: Fire effects on vegetation diversity, structure, and successional dynamics in shrub-steppe and mixed conifer environments of the Hells Canyon, Idaho Author: Havlina, Douglas William The effects of fire severity on post-fire succession and shrub demography were quantified in shrub-steppe grasslands and subalpine forests in the Hells Canyon of the Payette National Forest, Idaho. Following the 1988 Eagle Bar Fire, species frequency, community diversity, fire adaptations, and stand ages were quantified at 12 plots in burned and unburned forests. Pre-fire composition was dominated by Pseudotsuga menziesii, Pinus contorta, Abies grandis, and Abies lasiocarpa in the overstory. Prefire basal area ranged from 41 to 80 m 2 ha-1 . Pre-fire stand ages ranged from 71 years in Abies lasiocarpa forests to > 200 years in Pseudotsuga menziesii stands. Fire scenarios which were sampled consisted of: (1) complete stand-replacement fires; (2) partial standreplacement fires; and (3) unburned forests (control). Partial stand-replacement forests were characterized by significantly higher mean species diversity and richness (H'=3.16, S=36) than complete stand-replacement (H'=2.78, S=27) or unburned forests (H=2.26, S=15). Vegetation preferentially established in burned areas along a gradient of fire severity according to adapted fire guilds. Single-storied forests dominated by Pinus contorta and Abies lasiocarpa typified stand-replacement fire scenarios, with mean ages ranging from 99 to 159 years corresponding to fire return intervals common in this type. Multi-storied forests of Pseudotsuga menziesii in the overstory and Abies spp. in the mid-story comprised partial stand-replacement forests. Overstory stand ages ranged from 165 to 209 years, while mid-story ages ranged from 77 to 99 years, corresponding to fire-return intervals which characterize the intermediate, partial stand-replacement fire regime. In the Hells Canyon forests, fire is a dominant ecosystem process in the creation of landscape mosaics, in governing species distribution, and in the maintenance of biological diversity. Forests experiencing complete stand-replacement (n=4) were dominated by Salix scouleriana, a classic off-site colonizer. At the fourth post-fire year, Salix scouleriana density ranged from 252,000 shrubs ha' to 569,333 shrubs ha-1 . From the fourth to the fifth post-fire year, mean shrub density showed a significant decrease from 336,667 to 246,000 shrubs ha.4 . During this same period, mean shrub biomass significantly increased from 10.2 g shrub-1 to 33.1 g shrub"', mean aboveground biomass significantly increased from 2.95 to 7.05 Mg ha-1, and mean shrub height significantly increased from 62 to 100 cm shrub-1. Without competing conifers, Salix scouleriana may maintain site dominance for several decades. The 1992 Windy Ridge Fire burned approximately 2,000 ha of the Purshia tridentatal Agropyron spicatum plant association at elevations < 1460 m. Because Purshia tridentata survivorship appeared to be associated with plant age and ecotype, a multiple regression model was developed to partition burned and unburned shrubs into age class segments at n=10 sites. Pre-fire shrub density ranged from 400 to 1700 shrubs ha-1. Concomitant with Purshia tridentata decadence and stagnation following a lengthened fire-free interval were increases in post-fire mortality. Post-fire mortality of Purshia tridentata was closely associated with plant age (R2=0.91). Plants in age classes < 25 years of age exhibited 66% sprouting, while shrubs > 25 years of age had only 20% survival. Shrub mortality in burned communities ranged from 37% to 100%, while mortality among unburned communities averaged 5%. The reintroduction of fire appears to be a necessity for restoring certain Purshia tridentata ecotypes which have not entered stagnation. Continued fire exclusion may well result in the loss of many at risk Purshia tridentata communities. As an influence on ecosystem function, genetic variation, and landscape mosaics, fire represents a pervasive disturbance in the Hells Canyon ecosystems. Unique successional pathways result from fires which vary in dimension, severity, and periodicity, thereby contributing to diversity at all scales. Intrinsic adaptations to fire testify to the coevolution between flora and fire in the Hells Canyon, and illustrate the resiliency of biota in fire-dominated environments. Title: Fire effects on vegetation diversity, structure, and successional dynamics in shrub-steppe and mixed conifer environments of the Hells Canyon, Idaho Author: Havlina, Douglas William The effects of fire severity on post-fire succession and shrub demography were quantified in shrub-steppe grasslands and subalpine forests in the Hells Canyon of the Payette National Forest, Idaho. Following the 1988 Eagle Bar Fire, species frequency, community diversity, fire adaptations, and stand ages were quantified at 12 plots in burned and unburned forests. Pre-fire composition was dominated by Pseudotsuga menziesii, Pinus contorta, Abies grandis, and Abies lasiocarpa in the overstory. Prefire basal area ranged from 41 to 80 m 2 ha-1 . Pre-fire stand ages ranged from 71 years in Abies lasiocarpa forests to > 200 years in Pseudotsuga menziesii stands. Fire scenarios which were sampled consisted of: (1) complete stand-replacement fires; (2) partial standreplacement fires; and (3) unburned forests (control). Partial stand-replacement forests were characterized by significantly higher mean species diversity and richness (H'=3.16, S=36) than complete stand-replacement (H'=2.78, S=27) or unburned forests (H=2.26, S=15). Vegetation preferentially established in burned areas along a gradient of fire severity according to adapted fire guilds. Single-storied forests dominated by Pinus contorta and Abies lasiocarpa typified stand-replacement fire scenarios, with mean ages ranging from 99 to 159 years corresponding to fire return intervals common in this type. Multi-storied forests of Pseudotsuga menziesii in the overstory and Abies spp. in the mid-story comprised partial stand-replacement forests. Overstory stand ages ranged from 165 to 209 years, while mid-story ages ranged from 77 to 99 years, corresponding to fire-return intervals which characterize the intermediate, partial stand-replacement fire regime. In the Hells Canyon forests, fire is a dominant ecosystem process in the creation of landscape mosaics, in governing species distribution, and in the maintenance of biological diversity. Forests experiencing complete stand-replacement (n=4) were dominated by Salix scouleriana, a classic off-site colonizer. At the fourth post-fire year, Salix scouleriana density ranged from 252,000 shrubs ha' to 569,333 shrubs ha-1 . From the fourth to the fifth post-fire year, mean shrub density showed a significant decrease from 336,667 to 246,000 shrubs ha.4 . During this same period, mean shrub biomass significantly increased from 10.2 g shrub-1 to 33.1 g shrub"', mean aboveground biomass significantly increased from 2.95 to 7.05 Mg ha-1, and mean shrub height significantly increased from 62 to 100 cm shrub-1. Without competing conifers, Salix scouleriana may maintain site dominance for several decades. The 1992 Windy Ridge Fire burned approximately 2,000 ha of the Purshia tridentatal Agropyron spicatum plant association at elevations < 1460 m. Because Purshia tridentata survivorship appeared to be associated with plant age and ecotype, a multiple regression model was developed to partition burned and unburned shrubs into age class segments at n=10 sites. Pre-fire shrub density ranged from 400 to 1700 shrubs ha-1. Concomitant with Purshia tridentata decadence and stagnation following a lengthened fire-free interval were increases in post-fire mortality. Post-fire mortality of Purshia tridentata was closely associated with plant age (R2=0.91). Plants in age classes < 25 years of age exhibited 66% sprouting, while shrubs > 25 years of age had only 20% survival. Shrub mortality in burned communities ranged from 37% to 100%, while mortality among unburned communities averaged 5%. The reintroduction of fire appears to be a necessity for restoring certain Purshia tridentata ecotypes which have not entered stagnation. Continued fire exclusion may well result in the loss of many at risk Purshia tridentata communities. As an influence on ecosystem function, genetic variation, and landscape mosaics, fire represents a pervasive disturbance in the Hells Canyon ecosystems. Unique successional pathways result from fires which vary in dimension, severity, and periodicity, thereby contributing to diversity at all scales. Intrinsic adaptations to fire testify to the coevolution between flora and fire in the Hells Canyon, and illustrate the resiliency of biota in fire-dominated environments. Close

• 31. [Article] Climate change and vulnerability of bull trout (Salvelinus confluentus) in a fire-prone landscape

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by NRC Research ...

  Citation × Citation Citation Abstract Copy Title: Climate change and vulnerability of bull trout (Salvelinus confluentus) in a fire-prone landscape Author: Falke, Jeffrey A., Reeves, Gordon H., Hessburg, Paul F., Flitcroft, Rebecca L., Dunham, Jason B., McNyset, Kristina M. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by NRC Research Press and can be found at: http://www.nrcresearchpress.com/journal/cjfas. Title: Climate change and vulnerability of bull trout (Salvelinus confluentus) in a fire-prone landscape Author: Falke, Jeffrey A., Reeves, Gordon H., Hessburg, Paul F., Flitcroft, Rebecca L., Dunham, Jason B., McNyset, Kristina M. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by NRC Research Press and can be found at: http://www.nrcresearchpress.com/journal/cjfas. Close

• 32. [Article] The role of strategic planning in the management of fire-prone western Oregon forests for maximizing terrestrial carbon stocks over a 100-year horizon

  Current frameworks for analyzing forest carbon offset projects in disturbance-prone western forests often fail to address the dynamic nature of carbon pathways through time. They do not account for the ...

  Citation × Citation Citation Abstract Copy Title: The role of strategic planning in the management of fire-prone western Oregon forests for maximizing terrestrial carbon stocks over a 100-year horizon Author: Vanderberg, Michael R. Current frameworks for analyzing forest carbon offset projects in disturbance-prone western forests often fail to address the dynamic nature of carbon pathways through time. They do not account for the probability of loss due to wildfire, which can influence the prediction of carbon storage at the end of a planning horizon. In such an environment, optimal treatment regimes over time are dependent on the decisions that affect carbon storage during the analysis period. Silvicultural regimes that include both pyrogenic and biogenic emissions from forests, as well as the storage in wood products, were modeled to demonstrate a method to maximize carbon storage. Stand-level optimization is suggested as a method for demonstrating the development of treatment regimes to enable a full range of carbon storage benefits. These include a reduction in the risk of catastrophic wildfire, increased terrestrial carbon density, and the offset of treatment costs. This methodology may also provide a baseline for a full accounting of forestry carbon offset projects. A model was developed to determine optimal management regimes that maximize the expected value of terrestrial carbon storage for three Douglas-fir (Pseudotsuga menziessi) dominant forests in western Oregon. Carbon storage values for treatment combinations were weighted by the probability of fire occurrence and the loss of carbon due to fire. The model employs probabilistic dynamic programming to determine the optimal timing and intensity of silvicultural treatments by way of thinning-from-below. Also determined are location-dependent management regimes that maximize aboveground carbon storage with fire-suppression efforts. The stand location in respect to roads is examined, specifically in terms of the effect that access distance and slope position have on the optimal timing and intensity of fuel treatments and silvicultural activities. Optimal regimes are determined for a range of forest stands, varying by stand distance-to-road and the slope location of the road above or below the stand. Results suggest that a combination of let-grow and low-level density-reduction thinnings can store more aboveground terrestrial carbon in forests and long-lived wood products than grow-only control scenarios when fire is also present and fire-related emissions are accounted for. Additional expected carbon storage of optimal solutions compared to the 100-year gain for control scenarios ranged from 0 to 46%. This suggests that strategic planning by the optimization model can compete with the hedge method of the Voluntary Carbon Standard risk management, which employs carbon buffer pools to compensate for the risk associated with disturbance and can require the size of the buffer deposit to range from 10 to 60% of the generated carbon credits, depending on the risk class determined for a given project. Results also suggest that both stand location and fire suppression efforts did not impact the maximization of aboveground terrestrial carbon storage in forests and long-lived wood products under moderate fire conditions (21 km hr⁻¹ 6-meter wind speed, 31° C air temperature, 40% herbaceous and 70% woody fuel moisture). However, it was shown that stand slope position relative to access roads did impact fire suppression efforts by affecting the response time and the type of suppression effort (e.g., head attack or rear attack). It is hypothesized that both stand location and fire suppression efforts would impact the maximization of aboveground terrestrial carbon in forests and wood products under more severe weather conditions, on steeper slopes, and over larger stand areas. Title: The role of strategic planning in the management of fire-prone western Oregon forests for maximizing terrestrial carbon stocks over a 100-year horizon Author: Vanderberg, Michael R. Current frameworks for analyzing forest carbon offset projects in disturbance-prone western forests often fail to address the dynamic nature of carbon pathways through time. They do not account for the probability of loss due to wildfire, which can influence the prediction of carbon storage at the end of a planning horizon. In such an environment, optimal treatment regimes over time are dependent on the decisions that affect carbon storage during the analysis period. Silvicultural regimes that include both pyrogenic and biogenic emissions from forests, as well as the storage in wood products, were modeled to demonstrate a method to maximize carbon storage. Stand-level optimization is suggested as a method for demonstrating the development of treatment regimes to enable a full range of carbon storage benefits. These include a reduction in the risk of catastrophic wildfire, increased terrestrial carbon density, and the offset of treatment costs. This methodology may also provide a baseline for a full accounting of forestry carbon offset projects. A model was developed to determine optimal management regimes that maximize the expected value of terrestrial carbon storage for three Douglas-fir (Pseudotsuga menziessi) dominant forests in western Oregon. Carbon storage values for treatment combinations were weighted by the probability of fire occurrence and the loss of carbon due to fire. The model employs probabilistic dynamic programming to determine the optimal timing and intensity of silvicultural treatments by way of thinning-from-below. Also determined are location-dependent management regimes that maximize aboveground carbon storage with fire-suppression efforts. The stand location in respect to roads is examined, specifically in terms of the effect that access distance and slope position have on the optimal timing and intensity of fuel treatments and silvicultural activities. Optimal regimes are determined for a range of forest stands, varying by stand distance-to-road and the slope location of the road above or below the stand. Results suggest that a combination of let-grow and low-level density-reduction thinnings can store more aboveground terrestrial carbon in forests and long-lived wood products than grow-only control scenarios when fire is also present and fire-related emissions are accounted for. Additional expected carbon storage of optimal solutions compared to the 100-year gain for control scenarios ranged from 0 to 46%. This suggests that strategic planning by the optimization model can compete with the hedge method of the Voluntary Carbon Standard risk management, which employs carbon buffer pools to compensate for the risk associated with disturbance and can require the size of the buffer deposit to range from 10 to 60% of the generated carbon credits, depending on the risk class determined for a given project. Results also suggest that both stand location and fire suppression efforts did not impact the maximization of aboveground terrestrial carbon storage in forests and long-lived wood products under moderate fire conditions (21 km hr⁻¹ 6-meter wind speed, 31° C air temperature, 40% herbaceous and 70% woody fuel moisture). However, it was shown that stand slope position relative to access roads did impact fire suppression efforts by affecting the response time and the type of suppression effort (e.g., head attack or rear attack). It is hypothesized that both stand location and fire suppression efforts would impact the maximization of aboveground terrestrial carbon in forests and wood products under more severe weather conditions, on steeper slopes, and over larger stand areas. Close

• 33. [Article] A contingent valuation study of the value of reducing fire hazards to old-growth forests in the Pacific Northwest

  A contingent valuation methodology was applied to old-growth forests and critical habitat units for the Northern Spotted Owl in Oregon to esimate the economic value to the public in knowing that rare and ...

  Citation × Citation Citation Abstract Copy Title: A contingent valuation study of the value of reducing fire hazards to old-growth forests in the Pacific Northwest Author: Gregory, Robin (Robin Scott), Gonzalez-Caban, Armando, Loomis, John B. A contingent valuation methodology was applied to old-growth forests and critical habitat units for the Northern Spotted Owl in Oregon to esimate the economic value to the public in knowing that rare and unique ecosystems will be protected from fire for current and future generations. Generalizing to the whole state, the total annual willingness-to-pay of Oregon residents ranges from $49.6 to $99 million. In terms of old-growth forests protected from fire, the value is $28 per acre. Title: A contingent valuation study of the value of reducing fire hazards to old-growth forests in the Pacific Northwest Author: Gregory, Robin (Robin Scott), Gonzalez-Caban, Armando, Loomis, John B. A contingent valuation methodology was applied to old-growth forests and critical habitat units for the Northern Spotted Owl in Oregon to esimate the economic value to the public in knowing that rare and unique ecosystems will be protected from fire for current and future generations. Generalizing to the whole state, the total annual willingness-to-pay of Oregon residents ranges from $49.6 to $99 million. In terms of old-growth forests protected from fire, the value is $28 per acre. Close

• 34. [Article] Restoring forest health: Fire and thinning effects on mixed-conifer forests

  Even after 140 years without a fire, mixed-conifer forest such as Teakettle’s Experimental Forest has a distinct patch pattern and complex structure. Researcher Malcolm North and colleagues examined the structure ...

  Citation × Citation Citation Abstract Copy Title: Restoring forest health: Fire and thinning effects on mixed-conifer forests Author: North, Malcolm P. Even after 140 years without a fire, mixed-conifer forest such as Teakettle’s Experimental Forest has a distinct patch pattern and complex structure. Researcher Malcolm North and colleagues examined the structure and function of these ecosystems and their response to widely used restoration treatments. Collectively the studies found fire was essential to restoring many ecosystem processes and that thinning could be best used as a tool to influence burn intensity and extent. Title: Restoring forest health: Fire and thinning effects on mixed-conifer forests Author: North, Malcolm P. Even after 140 years without a fire, mixed-conifer forest such as Teakettle’s Experimental Forest has a distinct patch pattern and complex structure. Researcher Malcolm North and colleagues examined the structure and function of these ecosystems and their response to widely used restoration treatments. Collectively the studies found fire was essential to restoring many ecosystem processes and that thinning could be best used as a tool to influence burn intensity and extent. Close

• 35. [Article] Restoring forest health : fire and thinning effects on mixed-conifer forests

  Even after 140 years without a fire, mixed-conifer forest such as Teakettle’s Experimental Forest has a distinct patch pattern and complex structure. Researcher Malcolm North and colleagues examined the ...

  Citation × Citation Citation Abstract Copy Title: Restoring forest health : fire and thinning effects on mixed-conifer forests Even after 140 years without a fire, mixed-conifer forest such as Teakettle’s Experimental Forest has a distinct patch pattern and complex structure. Researcher Malcolm North and colleagues examined the structure and function of these ecosystems and their response to widely used restoration treatments. Collectively the studies found fire was essential to restoring many ecosystem processes and that thinning could be best used as a tool to influence burn intensity and extent. Includes interview with Malcolm P. North and suggested readings. Early draft of this issue of Science Perspectives by Anne M. Rosenthal, is a science writer based in the San Francisco Bay Area. Title: Restoring forest health : fire and thinning effects on mixed-conifer forests Even after 140 years without a fire, mixed-conifer forest such as Teakettle’s Experimental Forest has a distinct patch pattern and complex structure. Researcher Malcolm North and colleagues examined the structure and function of these ecosystems and their response to widely used restoration treatments. Collectively the studies found fire was essential to restoring many ecosystem processes and that thinning could be best used as a tool to influence burn intensity and extent. Includes interview with Malcolm P. North and suggested readings. Early draft of this issue of Science Perspectives by Anne M. Rosenthal, is a science writer based in the San Francisco Bay Area. Close

• 36. [Article] Fire ecology of ponderosa pine and the rebuilding of fire-resilient ponderosa pine ecoystems

  The ponderosa pine ecosystem of the West have changed dramatically since Euro-American settlement 140 years ago due to past land uses and the curtailment of natural fire. Today, ponderosa pine forests ...

  Citation × Citation Citation Abstract Copy Title: Fire ecology of ponderosa pine and the rebuilding of fire-resilient ponderosa pine ecoystems Author: Fitzgerald, Stephen Arthur The ponderosa pine ecosystem of the West have changed dramatically since Euro-American settlement 140 years ago due to past land uses and the curtailment of natural fire. Today, ponderosa pine forests contain over abundance of fuel, and stand densities have increased from a grange of 49-124 trees per ha (20-50 trees pper acre) to a range of 1235-2470 trees per ha (500 to 100 stems per acre). As a result, long-term stand and landscape health has been compromised and stand and landscape conditions now promote large, uncharacteristic wildfires. Reversing this trend is paramount. Improving the fire-resiliency of ponderosa pine forests requires understanding the connection between fire behavior and severity and the forest structure and fuels. Restoration treatments (thinning, prescribed fire, mowing, and other mechanical treatments) that reduce surface, ladder, and crown fuels can reduce fire severity and the potential for high-intensity crown fires. Understanding the historical role of fire in shaping ponderosa pine ecosystems is important for designing restoration treatments. Without intelligent, ecosystem-based restoration treatments in the near term, forest health and wildfire conditions will continue to deteriorate in the long term and the situation is not likely to rectify itself. Title: Fire ecology of ponderosa pine and the rebuilding of fire-resilient ponderosa pine ecoystems Author: Fitzgerald, Stephen Arthur The ponderosa pine ecosystem of the West have changed dramatically since Euro-American settlement 140 years ago due to past land uses and the curtailment of natural fire. Today, ponderosa pine forests contain over abundance of fuel, and stand densities have increased from a grange of 49-124 trees per ha (20-50 trees pper acre) to a range of 1235-2470 trees per ha (500 to 100 stems per acre). As a result, long-term stand and landscape health has been compromised and stand and landscape conditions now promote large, uncharacteristic wildfires. Reversing this trend is paramount. Improving the fire-resiliency of ponderosa pine forests requires understanding the connection between fire behavior and severity and the forest structure and fuels. Restoration treatments (thinning, prescribed fire, mowing, and other mechanical treatments) that reduce surface, ladder, and crown fuels can reduce fire severity and the potential for high-intensity crown fires. Understanding the historical role of fire in shaping ponderosa pine ecosystems is important for designing restoration treatments. Without intelligent, ecosystem-based restoration treatments in the near term, forest health and wildfire conditions will continue to deteriorate in the long term and the situation is not likely to rectify itself. Close

• 37. [Article] Synthesis of knowledge on the effects of fire and fire surrogates on wildlife in U.S. dry forests

  Published September 2009. Reviewed December 2013. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://exten...

  Citation × Citation Citation Abstract Copy Title: Synthesis of knowledge on the effects of fire and fire surrogates on wildlife in U.S. dry forests Author: Kennedy, Patricia L., Oregon State University. Agricultural Experiment Station, Fontaine, Joseph B. Published September 2009. Reviewed December 2013. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: Synthesis of knowledge on the effects of fire and fire surrogates on wildlife in U.S. dry forests Author: Kennedy, Patricia L., Oregon State University. Agricultural Experiment Station, Fontaine, Joseph B. Published September 2009. Reviewed December 2013. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 38. [Article] Mixed-Severity Fire Effects on Biological Legacies and Vegetation Response in Pseudotsuga Forests of Western Oregon's Central Cascades, USA

  Mixed-severity fire occurrence is increasingly recognized in Pseudotsuga forests of the Pacific Northwest, but questions remain about how tree mortality varies, and forest structure is altered, across ...

  Citation × Citation Citation Abstract Copy Title: Mixed-Severity Fire Effects on Biological Legacies and Vegetation Response in Pseudotsuga Forests of Western Oregon's Central Cascades, USA Author: Dunn, Christopher J. Mixed-severity fire occurrence is increasingly recognized in Pseudotsuga forests of the Pacific Northwest, but questions remain about how tree mortality varies, and forest structure is altered, across the disturbance gradient observed in these fires. Therefore, we sampled live and dead biological legacies at 45 one ha plots, with four 0.10 ha nested plots, stratified across an unburned, low, moderate and high-severity fire gradient. We used severity estimates based on differenced Normalized Burn Ratio (dNBR), and captured a disturbance gradient, but plots in our low-severity class underestimated fire effects because of misclassification or delayed mortality. We estimated probability of mortality for shade-intolerant (Douglas-fir, incense-cedar, sugar pine) and shade-tolerant (western hemlock, western redcedar, true fir) trees from 5,079 sampled trees and snags. The probability of mortality was higher for shade-tolerant species across all fire-severity classes, and decreased with increasing DBH except for western hemlock. Only large, shade-intolerant trees survived high-severity fire. Post-fire snag fall and fragmentation were estimated from 2,746 sampled snags and logs. The probability of snag fall decreased with increasing DBH for all species, and was positively correlated with fire severity, except for Douglas-fir that had a higher probability following low-severity fire. Snag fragmentation was positively correlated with DBH and fire severity for all species. We also estimated the coefficient of variation within- and among-plots by fire severity class, as well as across all sampled conditions. Structural attributes varied more within- than among-plots, likely a result of increasing sub-hectare patchy mortality as fire intensity increased. Although vertical and horizontal structural diversity increased at sub-hectare scales, the coefficient of variation was highest for all structural attributes when compared across all fire severity classes. Therefore, the range of fire effects observed in mixed-severity fires may be functionally important in creating structural complexity across landscapes, which is an important attribute of old-growth forests in the Pacific Northwest. Understory vegetation response to mixed-severity fires has not been characterized for these forests even though the majority of vegetation diversity is found in these vegetation layers. Therefore, we sampled forest structure (1000 m² circular plots) and understory vegetation (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. We focused on shrub species, but sampled forbs, graminoids, ferns and moss as functional groups. Offsite colonization and fire stimulated soil seedbanks increased the total species richness from 23 to 46. The life-history strategies of residual and colonizing species resulted in three dominant species response-curves to the magnitude of disturbance: 1) 'disturbance-sensitive', when relative abundance was highest in unburned plots and continued to decline with increasing fire severity, 2) 'disturbance-stimulated', when relative abundance was highest following low or moderate-severity fire and 3) 'disturbance-amplified', when relative abundance increased with increasing fire severity. Residual and colonizing species assemblages promoted five or six distinct understory communities, dominantly driven by legacy tree basal area rather than the proportion of basal area killed. Understory communities were rarely associated with one disturbance severity class as fire refugia, variation in overstory and understory fire severity, and compensatory conditions offset fire effects. Early-seral habitats were the most different from unburned forests, but were not the only post-fire conditions important across these burned landscapes. Interactions among live and dead forest structures following low or moderate-severity fire, and the vegetation response to these conditions, are also unique to the post-fire landscape and likely important for various wildlife species. Therefore, if ecological forestry paradigms focus dominantly on creating old-growth structure or early-seral habitats, they might exclude important conditions that contribute to the landscape structural complexity created by mixed-severity fires. Additionally, tree regeneration response to mixed-severity fires has not been characterized for these forests even though they offer insight into one aspect of the resilience of these ecosystems to disturbance. Therefore, we sampled forest structure (1000 m² circular plots) and regeneration dynamics (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. The largest marginal increase in tree mortality (stems ha⁻¹) occurred between unburned and low-severity fires, given preferential mortality of small trees and shade-tolerant species, but basal area mortality had the largest marginal increase moving from moderate to high-severity. Pairwise comparisons of legacy tree basal area between low and moderate-severity weren’t as significant as other comparisons, but did capture a gradient of increasing fire effects. Quadratic mean diameter and canopy base height were positively correlated with fire severity as incrementally larger trees were killed and canopy ascension followed. Regeneration density increased regardless of severity, relative to unburned forests (median density of 1,384 trees ha⁻¹), but the highest median density (16,220 trees ha⁻¹) followed low-severity fire at the Tiller Complex and moderate-severity fire (14,472 trees ha⁻¹) at Warner Fire. Plot-level average species richness was highest following these same fire severity classes, supporting the Intermediate Disturbance Hypothesis. Statistically distinct regeneration communities occurred across the fire severity gradient at both fire sites. The relative abundance of shade-tolerant tree species decreased as fire severity increased, except for a divergent response following stand-initiation at the Warner Fire. While divergent successional pathways were evident within a couple decades following stand-initiation, low or moderate-severity fires also modified successional trajectories and may be the most functionally important disturbance magnitude because it has the greatest potential to increase compositional and structural diversity. Incorporating mixed-severity fire effects into landscape management of Pseudotsuga forests could increase structural complexity at stand and landscape-scales. Title: Mixed-Severity Fire Effects on Biological Legacies and Vegetation Response in Pseudotsuga Forests of Western Oregon's Central Cascades, USA Author: Dunn, Christopher J. Mixed-severity fire occurrence is increasingly recognized in Pseudotsuga forests of the Pacific Northwest, but questions remain about how tree mortality varies, and forest structure is altered, across the disturbance gradient observed in these fires. Therefore, we sampled live and dead biological legacies at 45 one ha plots, with four 0.10 ha nested plots, stratified across an unburned, low, moderate and high-severity fire gradient. We used severity estimates based on differenced Normalized Burn Ratio (dNBR), and captured a disturbance gradient, but plots in our low-severity class underestimated fire effects because of misclassification or delayed mortality. We estimated probability of mortality for shade-intolerant (Douglas-fir, incense-cedar, sugar pine) and shade-tolerant (western hemlock, western redcedar, true fir) trees from 5,079 sampled trees and snags. The probability of mortality was higher for shade-tolerant species across all fire-severity classes, and decreased with increasing DBH except for western hemlock. Only large, shade-intolerant trees survived high-severity fire. Post-fire snag fall and fragmentation were estimated from 2,746 sampled snags and logs. The probability of snag fall decreased with increasing DBH for all species, and was positively correlated with fire severity, except for Douglas-fir that had a higher probability following low-severity fire. Snag fragmentation was positively correlated with DBH and fire severity for all species. We also estimated the coefficient of variation within- and among-plots by fire severity class, as well as across all sampled conditions. Structural attributes varied more within- than among-plots, likely a result of increasing sub-hectare patchy mortality as fire intensity increased. Although vertical and horizontal structural diversity increased at sub-hectare scales, the coefficient of variation was highest for all structural attributes when compared across all fire severity classes. Therefore, the range of fire effects observed in mixed-severity fires may be functionally important in creating structural complexity across landscapes, which is an important attribute of old-growth forests in the Pacific Northwest. Understory vegetation response to mixed-severity fires has not been characterized for these forests even though the majority of vegetation diversity is found in these vegetation layers. Therefore, we sampled forest structure (1000 m² circular plots) and understory vegetation (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. We focused on shrub species, but sampled forbs, graminoids, ferns and moss as functional groups. Offsite colonization and fire stimulated soil seedbanks increased the total species richness from 23 to 46. The life-history strategies of residual and colonizing species resulted in three dominant species response-curves to the magnitude of disturbance: 1) 'disturbance-sensitive', when relative abundance was highest in unburned plots and continued to decline with increasing fire severity, 2) 'disturbance-stimulated', when relative abundance was highest following low or moderate-severity fire and 3) 'disturbance-amplified', when relative abundance increased with increasing fire severity. Residual and colonizing species assemblages promoted five or six distinct understory communities, dominantly driven by legacy tree basal area rather than the proportion of basal area killed. Understory communities were rarely associated with one disturbance severity class as fire refugia, variation in overstory and understory fire severity, and compensatory conditions offset fire effects. Early-seral habitats were the most different from unburned forests, but were not the only post-fire conditions important across these burned landscapes. Interactions among live and dead forest structures following low or moderate-severity fire, and the vegetation response to these conditions, are also unique to the post-fire landscape and likely important for various wildlife species. Therefore, if ecological forestry paradigms focus dominantly on creating old-growth structure or early-seral habitats, they might exclude important conditions that contribute to the landscape structural complexity created by mixed-severity fires. Additionally, tree regeneration response to mixed-severity fires has not been characterized for these forests even though they offer insight into one aspect of the resilience of these ecosystems to disturbance. Therefore, we sampled forest structure (1000 m² circular plots) and regeneration dynamics (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. The largest marginal increase in tree mortality (stems ha⁻¹) occurred between unburned and low-severity fires, given preferential mortality of small trees and shade-tolerant species, but basal area mortality had the largest marginal increase moving from moderate to high-severity. Pairwise comparisons of legacy tree basal area between low and moderate-severity weren’t as significant as other comparisons, but did capture a gradient of increasing fire effects. Quadratic mean diameter and canopy base height were positively correlated with fire severity as incrementally larger trees were killed and canopy ascension followed. Regeneration density increased regardless of severity, relative to unburned forests (median density of 1,384 trees ha⁻¹), but the highest median density (16,220 trees ha⁻¹) followed low-severity fire at the Tiller Complex and moderate-severity fire (14,472 trees ha⁻¹) at Warner Fire. Plot-level average species richness was highest following these same fire severity classes, supporting the Intermediate Disturbance Hypothesis. Statistically distinct regeneration communities occurred across the fire severity gradient at both fire sites. The relative abundance of shade-tolerant tree species decreased as fire severity increased, except for a divergent response following stand-initiation at the Warner Fire. While divergent successional pathways were evident within a couple decades following stand-initiation, low or moderate-severity fires also modified successional trajectories and may be the most functionally important disturbance magnitude because it has the greatest potential to increase compositional and structural diversity. Incorporating mixed-severity fire effects into landscape management of Pseudotsuga forests could increase structural complexity at stand and landscape-scales. Close

• 39. [Article] Resilience to Stress and Disturbance, and Resistance to Bromus tectorum L. Invasion in Cold Desert Shrublands of Western North America

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Springer ...

  Citation × Citation Citation Abstract Copy Title: Resilience to Stress and Disturbance, and Resistance to Bromus tectorum L. Invasion in Cold Desert Shrublands of Western North America Author: Miller, Richard F., Germino, Matthew J., Grace, James B., D'Antonio, Carla, Brown, Cynthia S., Bradley, Bethany A., Hardegree, Stuart P., Pyke, David A., Chambers, Jeanne C. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/10021. Title: Resilience to Stress and Disturbance, and Resistance to Bromus tectorum L. Invasion in Cold Desert Shrublands of Western North America Author: Miller, Richard F., Germino, Matthew J., Grace, James B., D'Antonio, Carla, Brown, Cynthia S., Bradley, Bethany A., Hardegree, Stuart P., Pyke, David A., Chambers, Jeanne C. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/10021. Close

• 40. [Article] The effects of natural fire and recreational disturbance on montane forest ecosystem composition, structure and nitrogen dynamics, Crater Lake National Park, Oregon

  Disturbance, whether natural or of human origin, modifies to varying degrees many ecosystem attributes. Fire is a natural process in the montane forests of southern Oregon but for much of the 20th century ...

  Citation × Citation Citation Abstract Copy Title: The effects of natural fire and recreational disturbance on montane forest ecosystem composition, structure and nitrogen dynamics, Crater Lake National Park, Oregon Author: Wilson, John K. (John Kevin) Disturbance, whether natural or of human origin, modifies to varying degrees many ecosystem attributes. Fire is a natural process in the montane forests of southern Oregon but for much of the 20th century fire was viewed as an apocalypse and thus fervently suppressed. Effective natural resource management requires an understanding of how ecosystems function, including the ecological response to the natural disturbance regime or anthropogenically altered conditions. To describe the effects of natural fire and ecosystem changes with time following fire, I examined plant composition, structure, biomass and soil nitrogen using a chronosequence of sites ranging in age from 1 to >300 years. The ecological importance of human activity is a function of the magnitude and permanence of its effects which were described at active and abandoned recreation sites. Stand-replacing fires killed virtually 100% of the overstory trees, consumed 87% of the forest floor and resulted in a 27% loss in total aboveground biomass. A pulse of mineralized nitrogen was still apparent 2 years following fire. Two years following fire, little plant colonization was established. The availability of local seed sources, particularly seedbanking species, appears to have been an important determinant of the early-successional community composition. The developing community was dominated by nitrogen-fixing species which may play an important role in the post-fire nitrogen dynamics in these ecosystems. Conifer seedling densities measured 667 individuals/ha 8 years following fire and 1714 individuals/ha 24 years after fire. Extended tree maturation and variation in composition characterized the forest structure and composition during secondary succession. Total aboveground biomass remained high and accumulation followed a general U-shaped curve. Recreational use resulted in a reduction in tree density and biomass at all active sites. The greatest reductions occurred at sites set in late-successional forests. Compositional change was also greatest at sites established in late-successional forest with increased dominance of lodgepole pine and graminoids. Within 40 years the abandoned, mid-successional sites had recovered from most of the recreational impacts; however 40 years was not sufficient for late-successional forest recovery. These results suggest that the stage of succession should be considered when assessing potential recreational impacts. Title: The effects of natural fire and recreational disturbance on montane forest ecosystem composition, structure and nitrogen dynamics, Crater Lake National Park, Oregon Author: Wilson, John K. (John Kevin) Disturbance, whether natural or of human origin, modifies to varying degrees many ecosystem attributes. Fire is a natural process in the montane forests of southern Oregon but for much of the 20th century fire was viewed as an apocalypse and thus fervently suppressed. Effective natural resource management requires an understanding of how ecosystems function, including the ecological response to the natural disturbance regime or anthropogenically altered conditions. To describe the effects of natural fire and ecosystem changes with time following fire, I examined plant composition, structure, biomass and soil nitrogen using a chronosequence of sites ranging in age from 1 to >300 years. The ecological importance of human activity is a function of the magnitude and permanence of its effects which were described at active and abandoned recreation sites. Stand-replacing fires killed virtually 100% of the overstory trees, consumed 87% of the forest floor and resulted in a 27% loss in total aboveground biomass. A pulse of mineralized nitrogen was still apparent 2 years following fire. Two years following fire, little plant colonization was established. The availability of local seed sources, particularly seedbanking species, appears to have been an important determinant of the early-successional community composition. The developing community was dominated by nitrogen-fixing species which may play an important role in the post-fire nitrogen dynamics in these ecosystems. Conifer seedling densities measured 667 individuals/ha 8 years following fire and 1714 individuals/ha 24 years after fire. Extended tree maturation and variation in composition characterized the forest structure and composition during secondary succession. Total aboveground biomass remained high and accumulation followed a general U-shaped curve. Recreational use resulted in a reduction in tree density and biomass at all active sites. The greatest reductions occurred at sites set in late-successional forests. Compositional change was also greatest at sites established in late-successional forest with increased dominance of lodgepole pine and graminoids. Within 40 years the abandoned, mid-successional sites had recovered from most of the recreational impacts; however 40 years was not sufficient for late-successional forest recovery. These results suggest that the stage of succession should be considered when assessing potential recreational impacts. Close

• 41. [Article] Forest vegetation and fuel dynamics following stand-replacing wildfire, re-burn, and postfire management in the Siskiyou Mountains, Oregon

  Following high-severity fire, forest succession may take alternate pathways depending on the pattern of the fire and any secondary disturbances during early stand development, with lasting consequences ...

  Citation × Citation Citation Abstract Copy Title: Forest vegetation and fuel dynamics following stand-replacing wildfire, re-burn, and postfire management in the Siskiyou Mountains, Oregon Author: Donato, Daniel C. Following high-severity fire, forest succession may take alternate pathways depending on the pattern of the fire and any secondary disturbances during early stand development, with lasting consequences for ecosystem function. The objectives of this research were to quantify: (1) early postfire regeneration as influenced by the spatial pattern of a landscape-scale wildfire, and (2) the influence of secondary disturbances during early succession, specifically recurrent high-severity fire and postfire logging. Four years after the 200,000-hectare Biscuit Fire, patch-scale conifer seedling density was 80% Douglas-fir (Pseudotsuga menziesii) and ranged from 127-6494 stems/ha. Median density (1603 stems/ha) was ~12 times the prefire overstory density of 134 stems/ha. Due to the mixed-severity fire mosaic, ~58% of high-severity area was ≤ 200 m from patches of live trees, and ~81% was ≤ 400 m. Median conifer density exceeded 1000 stems/ha out to 400 m distance before declining rapidly at larger distances. Following a short-interval (15-year) repeat fire, vegetation communities contained nearly all species found in mature/old-growth stands and after a single fire, indicating high community persistence through two severe fires. The short-interval burn had the highest species richness and plant cover with additions of disturbance-adapted forbs and low shrubs, likely associated with a propagule bank that developed between fires. Sprouting capacity of hardwoods and shrubs was unaltered by recurrent fire, and conifer regeneration density (median 1495 stems/ha) was similar to single burn stands. Three to four years after fire, high-intensity postfire logging resulted in a greater proportion (28%) of felled biomass left on site as slash compared to moderate-intensity logging (14%), because tree felling was less selective. However, despite bole removal and slash generation, there was no significant difference in surface woody fuels among logged and unlogged treatments at 17-18 years after fire. Fuel profiles and fire modeling both suggested that regenerating vegetation rather than residual dead wood is the main driver of early seral fire hazard, with low fire potentials 3-4 years postfire and very high potentials at 17-18 years. Postfire logging increased fire potentials within this context due to generation of slash, with differences fading in ~15-20 years. The results from this research underscore the importance of the mixed-severity context in which stand-replacing fire often occurs, both for providing seed sources within a fire and for highly variable disturbances that interact with succession and plant adaptation. Title: Forest vegetation and fuel dynamics following stand-replacing wildfire, re-burn, and postfire management in the Siskiyou Mountains, Oregon Author: Donato, Daniel C. Following high-severity fire, forest succession may take alternate pathways depending on the pattern of the fire and any secondary disturbances during early stand development, with lasting consequences for ecosystem function. The objectives of this research were to quantify: (1) early postfire regeneration as influenced by the spatial pattern of a landscape-scale wildfire, and (2) the influence of secondary disturbances during early succession, specifically recurrent high-severity fire and postfire logging. Four years after the 200,000-hectare Biscuit Fire, patch-scale conifer seedling density was 80% Douglas-fir (Pseudotsuga menziesii) and ranged from 127-6494 stems/ha. Median density (1603 stems/ha) was ~12 times the prefire overstory density of 134 stems/ha. Due to the mixed-severity fire mosaic, ~58% of high-severity area was ≤ 200 m from patches of live trees, and ~81% was ≤ 400 m. Median conifer density exceeded 1000 stems/ha out to 400 m distance before declining rapidly at larger distances. Following a short-interval (15-year) repeat fire, vegetation communities contained nearly all species found in mature/old-growth stands and after a single fire, indicating high community persistence through two severe fires. The short-interval burn had the highest species richness and plant cover with additions of disturbance-adapted forbs and low shrubs, likely associated with a propagule bank that developed between fires. Sprouting capacity of hardwoods and shrubs was unaltered by recurrent fire, and conifer regeneration density (median 1495 stems/ha) was similar to single burn stands. Three to four years after fire, high-intensity postfire logging resulted in a greater proportion (28%) of felled biomass left on site as slash compared to moderate-intensity logging (14%), because tree felling was less selective. However, despite bole removal and slash generation, there was no significant difference in surface woody fuels among logged and unlogged treatments at 17-18 years after fire. Fuel profiles and fire modeling both suggested that regenerating vegetation rather than residual dead wood is the main driver of early seral fire hazard, with low fire potentials 3-4 years postfire and very high potentials at 17-18 years. Postfire logging increased fire potentials within this context due to generation of slash, with differences fading in ~15-20 years. The results from this research underscore the importance of the mixed-severity context in which stand-replacing fire often occurs, both for providing seed sources within a fire and for highly variable disturbances that interact with succession and plant adaptation. Close

• 42. [Article] Science basis for changing forest structure to modify wildfire behavior and severity

  Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical ...

  Citation × Citation Citation Abstract Copy Title: Science basis for changing forest structure to modify wildfire behavior and severity Author: Graham, Russell T., McCaffrey, Sarah, Jain, Theresa B. Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical setting, fuels, and weather combine to determine wildfire intensity (the rate at which it consumes fuel) and severity (the effect fire has on vegetation, soils, buildings, watersheds, and so forth). Millions of acres of forestlands (mainly in dry forests dominated by ponderosa pine and/or Douglas-fir) contain a high accumulation of flammable fuels compared to conditions prior to the 20th century. Forests with high stem density and fuel loading combined with extreme fire weather conditions have led to severe and large wildfires (such as those seen in the summers of 2000, 2002, and 2003) that have put a number of important values at risk. Although homes in the path of a wildfire are perhaps the most immediately recognized value, these wildfires also put numerous other human and ecological values at risk, such as power grids, drinking water supplies, firefighter safety, critical habitat, soil productivity, and air quality. For a given set of weather conditions, fire behavior is strongly influenced by stand and fuel structure. Crown fires in the dry forest types represent an increasing challenge for fire management as well as a general threat to the ecology of these forests and the closely associated human values. Crown fires are dependent on the sequence of available fuels starting from the ground surface to the canopy. Limiting crown fire in these forests can be accomplished by actions that manage in concert the surface, ladder, and crown fuels. Reducing crown fire and wildland fire growth across landscapes decreases the chances of developing large wildfires that affect human values adjacent to forested areas. However, a narrow focus on minimizing crown fire potential will not necessarily reduce the damage to homes and ecosystems when fires do occur. Homes are often ignited by embers flying far from the fire front, and by surface fires. Fire effects on ecosystems can also occur during surface fires where surface and understory fuels and deep organic layers are sufficient to generate high temperatures for long periods. Fuel treatments can help produce forest structures and fuel characteristics that then reduce the likelihood that wildfires will cause large, rapid changes in biophysical conditions. Fuel treatments can also help modify fire behavior sufficiently so that some wildfires can be suppressed more easily. Subsequent, sustained fuel treatments can maintain these conditions. Different fuel reduction methods target different components of the fuel bed. Thinning mainly affects standing vegetation, and other types of fuel treatments such as prescribed fire and pile burning woody fuels are needed to modify the combustion environment of surface fuels. In forests that have not experienced fire for many decades, multiple fuel treatments—that is, thinning and surface fuel reduction—may be required to significantly affect crown fire and surface fire hazard. Fuel treatments cannot guarantee benign fire behavior but can reduce the probability that extreme fire behavior will occur. Fuel treatments can be designed to restore forest conditions to a more resilient and resistant condition than now exists in many forests, and subsequent management could maintain these conditions, particularly in dry forests (ponderosa pine and Douglas-fir) where crown fires were historically infrequent. The degree of risk reduction will depend to some degree on the level of investment, social and economic acceptability of treatments, and concurrent consideration of other resource values (for example, wildlife). This report describes the kinds, quality, amount, and gaps of scientific knowledge for making informed decisions on fuel treatments used to modify wildfire behavior and effects in dry forests of the interior Western United States (especially forests dominated by ponderosa pine and Douglas-fir). A review of scientific principles and applications relevant to fuel treatment primarily for the dry forests is provided for the following topics: fuels, fire hazard, fire behavior, fire effects, forest structure, treatment effects and longevity, landscape fuel patterns, and scientific tools useful for management and planning. Title: Science basis for changing forest structure to modify wildfire behavior and severity Author: Graham, Russell T., McCaffrey, Sarah, Jain, Theresa B. Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical setting, fuels, and weather combine to determine wildfire intensity (the rate at which it consumes fuel) and severity (the effect fire has on vegetation, soils, buildings, watersheds, and so forth). Millions of acres of forestlands (mainly in dry forests dominated by ponderosa pine and/or Douglas-fir) contain a high accumulation of flammable fuels compared to conditions prior to the 20th century. Forests with high stem density and fuel loading combined with extreme fire weather conditions have led to severe and large wildfires (such as those seen in the summers of 2000, 2002, and 2003) that have put a number of important values at risk. Although homes in the path of a wildfire are perhaps the most immediately recognized value, these wildfires also put numerous other human and ecological values at risk, such as power grids, drinking water supplies, firefighter safety, critical habitat, soil productivity, and air quality. For a given set of weather conditions, fire behavior is strongly influenced by stand and fuel structure. Crown fires in the dry forest types represent an increasing challenge for fire management as well as a general threat to the ecology of these forests and the closely associated human values. Crown fires are dependent on the sequence of available fuels starting from the ground surface to the canopy. Limiting crown fire in these forests can be accomplished by actions that manage in concert the surface, ladder, and crown fuels. Reducing crown fire and wildland fire growth across landscapes decreases the chances of developing large wildfires that affect human values adjacent to forested areas. However, a narrow focus on minimizing crown fire potential will not necessarily reduce the damage to homes and ecosystems when fires do occur. Homes are often ignited by embers flying far from the fire front, and by surface fires. Fire effects on ecosystems can also occur during surface fires where surface and understory fuels and deep organic layers are sufficient to generate high temperatures for long periods. Fuel treatments can help produce forest structures and fuel characteristics that then reduce the likelihood that wildfires will cause large, rapid changes in biophysical conditions. Fuel treatments can also help modify fire behavior sufficiently so that some wildfires can be suppressed more easily. Subsequent, sustained fuel treatments can maintain these conditions. Different fuel reduction methods target different components of the fuel bed. Thinning mainly affects standing vegetation, and other types of fuel treatments such as prescribed fire and pile burning woody fuels are needed to modify the combustion environment of surface fuels. In forests that have not experienced fire for many decades, multiple fuel treatments—that is, thinning and surface fuel reduction—may be required to significantly affect crown fire and surface fire hazard. Fuel treatments cannot guarantee benign fire behavior but can reduce the probability that extreme fire behavior will occur. Fuel treatments can be designed to restore forest conditions to a more resilient and resistant condition than now exists in many forests, and subsequent management could maintain these conditions, particularly in dry forests (ponderosa pine and Douglas-fir) where crown fires were historically infrequent. The degree of risk reduction will depend to some degree on the level of investment, social and economic acceptability of treatments, and concurrent consideration of other resource values (for example, wildlife). This report describes the kinds, quality, amount, and gaps of scientific knowledge for making informed decisions on fuel treatments used to modify wildfire behavior and effects in dry forests of the interior Western United States (especially forests dominated by ponderosa pine and Douglas-fir). A review of scientific principles and applications relevant to fuel treatment primarily for the dry forests is provided for the following topics: fuels, fire hazard, fire behavior, fire effects, forest structure, treatment effects and longevity, landscape fuel patterns, and scientific tools useful for management and planning. Close

• 43. [Article] Science basis for changing forest structure to modify wildfire behavior and severity

  Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical ...

  Citation × Citation Citation Abstract Copy Title: Science basis for changing forest structure to modify wildfire behavior and severity Author: Graham, Russell T., McCaffrey, Sarah, Jain, Theresa B. Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical setting, fuels, and weather combine to determine wildfire intensity (the rate at which it consumes fuel) and severity (the effect fire has on vegetation, soils, buildings, watersheds, and so forth). Millions of acres of forestlands (mainly in dry forests dominated by ponderosa pine and/or Douglas-fir) contain a high accumulation of flammable fuels compared to conditions prior to the 20th century. Forests with high stem density and fuel loading combined with extreme fire weather conditions have led to severe and large wildfires (such as those seen in the summers of 2000, 2002, and 2003) that have put a number of important values at risk. Although homes in the path of a wildfire are perhaps the most immediately recognized value, these wildfires also put numerous other human and ecological values at risk, such as power grids, drinking water supplies, firefighter safety, critical habitat, soil productivity, and air quality. For a given set of weather conditions, fire behavior is strongly influenced by stand and fuel structure. Crown fires in the dry forest types represent an increasing challenge for fire management as well as a general threat to the ecology of these forests and the closely associated human values. Crown fires are dependent on the sequence of available fuels starting from the ground surface to the canopy. Limiting crown fire in these forests can be accomplished by actions that manage in concert the surface, ladder, and crown fuels. Reducing crown fire and wildland fire growth across landscapes decreases the chances of developing large wildfires that affect human values adjacent to forested areas. However, a narrow focus on minimizing crown fire potential will not necessarily reduce the damage to homes and ecosystems when fires do occur. Homes are often ignited by embers flying far from the fire front, and by surface fires. Fire effects on ecosystems can also occur during surface fires where surface and understory fuels and deep organic layers are sufficient to generate high temperatures for long periods. Fuel treatments can help produce forest structures and fuel characteristics that then reduce the likelihood that wildfires will cause large, rapid changes in biophysical conditions. Fuel treatments can also help modify fire behavior sufficiently so that some wildfires can be suppressed more easily. Subsequent, sustained fuel treatments can maintain these conditions. Different fuel reduction methods target different components of the fuel bed. Thinning mainly affects standing vegetation, and other types of fuel treatments such as prescribed fire and pile burning woody fuels are needed to modify the combustion environment of surface fuels. In forests that have not experienced fire for many decades, multiple fuel treatments—that is, thinning and surface fuel reduction—may be required to significantly affect crown fire and surface fire hazard. Fuel treatments cannot guarantee benign fire behavior but can reduce the probability that extreme fire behavior will occur. Fuel treatments can be designed to restore forest conditions to a more resilient and resistant condition than now exists in many forests, and subsequent management could maintain these conditions, particularly in dry forests (ponderosa pine and Douglas-fir) where crown fires were historically infrequent. The degree of risk reduction will depend to some degree on the level of investment, social and economic acceptability of treatments, and concurrent consideration of other resource values (for example, wildlife). This report describes the kinds, quality, amount, and gaps of scientific knowledge for making informed decisions on fuel treatments used to modify wildfire behavior and effects in dry forests of the interior Western United States (especially forests dominated by ponderosa pine and Douglas-fir). A review of scientific principles and applications relevant to fuel treatment primarily for the dry forests is provided for the following topics: fuels, fire hazard, fire behavior, fire effects, forest structure, treatment effects and longevity, landscape fuel patterns, and scientific tools useful for management and planning. Title: Science basis for changing forest structure to modify wildfire behavior and severity Author: Graham, Russell T., McCaffrey, Sarah, Jain, Theresa B. Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical setting, fuels, and weather combine to determine wildfire intensity (the rate at which it consumes fuel) and severity (the effect fire has on vegetation, soils, buildings, watersheds, and so forth). Millions of acres of forestlands (mainly in dry forests dominated by ponderosa pine and/or Douglas-fir) contain a high accumulation of flammable fuels compared to conditions prior to the 20th century. Forests with high stem density and fuel loading combined with extreme fire weather conditions have led to severe and large wildfires (such as those seen in the summers of 2000, 2002, and 2003) that have put a number of important values at risk. Although homes in the path of a wildfire are perhaps the most immediately recognized value, these wildfires also put numerous other human and ecological values at risk, such as power grids, drinking water supplies, firefighter safety, critical habitat, soil productivity, and air quality. For a given set of weather conditions, fire behavior is strongly influenced by stand and fuel structure. Crown fires in the dry forest types represent an increasing challenge for fire management as well as a general threat to the ecology of these forests and the closely associated human values. Crown fires are dependent on the sequence of available fuels starting from the ground surface to the canopy. Limiting crown fire in these forests can be accomplished by actions that manage in concert the surface, ladder, and crown fuels. Reducing crown fire and wildland fire growth across landscapes decreases the chances of developing large wildfires that affect human values adjacent to forested areas. However, a narrow focus on minimizing crown fire potential will not necessarily reduce the damage to homes and ecosystems when fires do occur. Homes are often ignited by embers flying far from the fire front, and by surface fires. Fire effects on ecosystems can also occur during surface fires where surface and understory fuels and deep organic layers are sufficient to generate high temperatures for long periods. Fuel treatments can help produce forest structures and fuel characteristics that then reduce the likelihood that wildfires will cause large, rapid changes in biophysical conditions. Fuel treatments can also help modify fire behavior sufficiently so that some wildfires can be suppressed more easily. Subsequent, sustained fuel treatments can maintain these conditions. Different fuel reduction methods target different components of the fuel bed. Thinning mainly affects standing vegetation, and other types of fuel treatments such as prescribed fire and pile burning woody fuels are needed to modify the combustion environment of surface fuels. In forests that have not experienced fire for many decades, multiple fuel treatments—that is, thinning and surface fuel reduction—may be required to significantly affect crown fire and surface fire hazard. Fuel treatments cannot guarantee benign fire behavior but can reduce the probability that extreme fire behavior will occur. Fuel treatments can be designed to restore forest conditions to a more resilient and resistant condition than now exists in many forests, and subsequent management could maintain these conditions, particularly in dry forests (ponderosa pine and Douglas-fir) where crown fires were historically infrequent. The degree of risk reduction will depend to some degree on the level of investment, social and economic acceptability of treatments, and concurrent consideration of other resource values (for example, wildlife). This report describes the kinds, quality, amount, and gaps of scientific knowledge for making informed decisions on fuel treatments used to modify wildfire behavior and effects in dry forests of the interior Western United States (especially forests dominated by ponderosa pine and Douglas-fir). A review of scientific principles and applications relevant to fuel treatment primarily for the dry forests is provided for the following topics: fuels, fire hazard, fire behavior, fire effects, forest structure, treatment effects and longevity, landscape fuel patterns, and scientific tools useful for management and planning. Close

• 44. [Article] Evaluation of the effects of silvicultural and fuels treatments on potential fire behaviour in Sierra Nevada mixed-conifer forests

  Fire suppression has increased fuel loads and fuel continuity in mixed-conifer ecosystems, resulting in forest structures that are vulnerable to catastrophic fire. This paper models fire behaviour in a ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of the effects of silvicultural and fuels treatments on potential fire behaviour in Sierra Nevada mixed-conifer forests Author: Stephens, Scott Lewis Fire suppression has increased fuel loads and fuel continuity in mixed-conifer ecosystems, resulting in forest structures that are vulnerable to catastrophic fire. This paper models fire behaviour in a mixed-conifer forest and investigates how silvicultural and fuels treatments affect potential fire behaviour. The computer program FARSITE was used to spatially and temporally model fire growth and behaviour. Fire modelling was performed in the North Crane Creek watershed of Yosemite National Park. Treatments were simulated by adjusting fuel total load, load-by-size class, depth., height-to-live crown base, tree height, and crown density parameters. Treatments modeled included prescribed burn, pile and burn, cut and scatter, thinning and biomass, thinning and biomass followed by prescribed burn, and salvage or group selection harvest with and without slash and landscape-level fuel treatment. The prescribed burn, thinning and biomassing followed by prescribed burn, and salvage or group selection with slash and landscape fuel treatments resulted in the lowest average fireline intensities, heat per unit area, rate of spread, area burned, and scorch heights. Cut and scatter, salvage or group selection treatments that do not treat slash fuels resulted in fire behaviour that is more extreme than the untreated forest. Restoration of mixed-conifer ecosystems must include an examination of how proposed treatments affect fuel structures. Combinations of prescribed fire andror mechanical treatments can be used to reduce wildfire hazard. Title: Evaluation of the effects of silvicultural and fuels treatments on potential fire behaviour in Sierra Nevada mixed-conifer forests Author: Stephens, Scott Lewis Fire suppression has increased fuel loads and fuel continuity in mixed-conifer ecosystems, resulting in forest structures that are vulnerable to catastrophic fire. This paper models fire behaviour in a mixed-conifer forest and investigates how silvicultural and fuels treatments affect potential fire behaviour. The computer program FARSITE was used to spatially and temporally model fire growth and behaviour. Fire modelling was performed in the North Crane Creek watershed of Yosemite National Park. Treatments were simulated by adjusting fuel total load, load-by-size class, depth., height-to-live crown base, tree height, and crown density parameters. Treatments modeled included prescribed burn, pile and burn, cut and scatter, thinning and biomass, thinning and biomass followed by prescribed burn, and salvage or group selection harvest with and without slash and landscape-level fuel treatment. The prescribed burn, thinning and biomassing followed by prescribed burn, and salvage or group selection with slash and landscape fuel treatments resulted in the lowest average fireline intensities, heat per unit area, rate of spread, area burned, and scorch heights. Cut and scatter, salvage or group selection treatments that do not treat slash fuels resulted in fire behaviour that is more extreme than the untreated forest. Restoration of mixed-conifer ecosystems must include an examination of how proposed treatments affect fuel structures. Combinations of prescribed fire andror mechanical treatments can be used to reduce wildfire hazard. Close

• 45. [Article] Evaluation of the effects of silvicultural and fuels treatments on potential fire behaviour in Sierra Nevada mixed-conifer forests

  Fire suppression has increased fuel loads and fuel continuity in mixed-conifer ecosystems, resulting in forest structures that are vulnerable to catastrophic fire. This paper models fire behaviour in a ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of the effects of silvicultural and fuels treatments on potential fire behaviour in Sierra Nevada mixed-conifer forests Author: Stephens, Scott L. Fire suppression has increased fuel loads and fuel continuity in mixed-conifer ecosystems, resulting in forest structures that are vulnerable to catastrophic fire. This paper models fire behaviour in a mixed-conifer forest and investigates how silvicultural and fuels treatments affect potential fire behaviour. The computer program FARSITE was used to spatially and temporally model fire growth and behaviour. Fire modelling was performed in the North Crane Creek watershed of Yosemite National Park. Treatments were simulated by adjusting fuel (total load, load-by-size class, depth.) height-to-live crown base, tree height, and crown density parameters. Treatments modeled included prescribed burn, pile and burn, cut and scatter, thinning and biomass, thinning and biomass followed by prescribed burn, and salvage or group selection harvest with and without slash and landscape-level fuel treatment. The prescribed burn, thinning and biomassing followed by prescribed burn, and salvage or group selection with slash and landscape fuel treatments resulted in the lowest average fireline intensities, heat per unit area, rate of spread, area burned, and scorch heights. Cut and scatter, salvage or group selection treatments that do not treat slash fuels resulted in fire behaviour that is more extreme than the untreated forest. Restoration of mixed-conifer ecosystems must include an examination of how proposed treatments affect fuel structures. Combinations of prescribed fire and/or mechanical treatments can be used to reduce wildfire hazard. Title: Evaluation of the effects of silvicultural and fuels treatments on potential fire behaviour in Sierra Nevada mixed-conifer forests Author: Stephens, Scott L. Fire suppression has increased fuel loads and fuel continuity in mixed-conifer ecosystems, resulting in forest structures that are vulnerable to catastrophic fire. This paper models fire behaviour in a mixed-conifer forest and investigates how silvicultural and fuels treatments affect potential fire behaviour. The computer program FARSITE was used to spatially and temporally model fire growth and behaviour. Fire modelling was performed in the North Crane Creek watershed of Yosemite National Park. Treatments were simulated by adjusting fuel (total load, load-by-size class, depth.) height-to-live crown base, tree height, and crown density parameters. Treatments modeled included prescribed burn, pile and burn, cut and scatter, thinning and biomass, thinning and biomass followed by prescribed burn, and salvage or group selection harvest with and without slash and landscape-level fuel treatment. The prescribed burn, thinning and biomassing followed by prescribed burn, and salvage or group selection with slash and landscape fuel treatments resulted in the lowest average fireline intensities, heat per unit area, rate of spread, area burned, and scorch heights. Cut and scatter, salvage or group selection treatments that do not treat slash fuels resulted in fire behaviour that is more extreme than the untreated forest. Restoration of mixed-conifer ecosystems must include an examination of how proposed treatments affect fuel structures. Combinations of prescribed fire and/or mechanical treatments can be used to reduce wildfire hazard. Close

• 46. [Article] Characterization of fire effects on forest ecosystems in the Tillamook Forest, Oregon

  From the 1920's through 1951 several severe fires occurred in the predominantly conifer forest ecosystems of the northern Oregon Coast Range. Of the 211,151 ha. of mapped area, 57 percent was burned. The ...

  Citation × Citation Citation Abstract Copy Title: Characterization of fire effects on forest ecosystems in the Tillamook Forest, Oregon Author: Chen, Shu-Huei From the 1920's through 1951 several severe fires occurred in the predominantly conifer forest ecosystems of the northern Oregon Coast Range. Of the 211,151 ha. of mapped area, 57 percent was burned. The effects of frequent fires with high severity on forest ecosystems over time at the landscape level is not fully understood. A reconstruction of fire history was conducted to help investigate the effects of fire severity, frequency, and area extent on distribution of postfire tree regeneration, species composition, and stand tree size, as well as on current species composition and stand tree size. I hypothesized that: 1) vegetation patterns (1950's and 1988) would vary with time, because the persistence of disturbance effects (fire, logging, reforestation) on forest vegetative responses varied, and 2) environmental controls (topography, soil, climate) would become the primary influences when disturbance events were absent. In this study historical maps, sketches and notes were used to reconstruct spatial and temporal patterns of fires from the 1920's to 1951 and to identify unburned patches on a Geographic Information System. Relationships between fire regime and postfire and current vegetative patterns were tested. Constructing precise spatial data layers from early maps, produced before the availability of aerial photography or satellite image, was difficult. Historical map accuracy and quality were variable and poor by present day standards. Geographic reference points were used to transform inappropriate map scales. The reconstruction of spatial data was used to characterize spatial patterns of historic fires: my estimates of burn areas were similar to estimates in the literature. To reduce questionable data along fire and vegetation patch boundaries for hypothesis testing, an exclusion approach was used. Data within a 100 m width of fire and vegetation type boundary lines were called a fuzzy zone and removed from raw data. The distribution of various attributes in the reduced data was similar to the distribution of the complete data set. Regression analysis examined the effects of fire, logging, reforestation, topography, climate, and soil type on vegetation patterns. Patterns of postfire (1950's) species composition, tree regeneration and tree size (DBH) were associated with the effects of fires, as well as influences of logging and soil type. Indices of fire occurrences (reflecting the time variation and severity of fires) frequently correlated to the 1950's vegetation patterns. The number of fires (frequency) did not cause great differences in vegetation patterns. Current (1988) species composition and tree size (after absence of fire for more than three decades) were correlated more with terrain variables. Plant succession also influenced the current vegetation patterns. Neither the date or number of fires caused marked differences in distribution of species and tree size, except large conifers were found in areas missed by fires. Postfire and current vegetation patterns were correlated with soil types which reflect the influence of topographic and climatic characteristics. However, historic fires occurred frequently on some soil types. Fires have a confounding influence on soil type. This confounding influence of fire on soil type cannot be avoided. Reforestation efforts appeared to have little influence on the postfire and current vegetation patterns. I inferred that the short time period of reforestation effects did not show its importance on the 1950's vegetation landscape. Although regression analysis results did not support my hypothesis, by 1988, reforested area in the northern Coast Range had increased since 1950's. Most of the large fire-open patches became mixed forest in about 3 decades may still relate to the force of reforestation. On private unburned ownerships conifer forests in 1955 were subsequently cut and replaced by mostly mixed forest by 1988. The analysis supported the hypotheses that soil type, aspect and plant succession were dominant influences on current (1988) vegetation patterns, while forest disturbances such as fire and logging were important influences on the immediate postfire (1950's) patterns. The results not only interpret the relationship between historic disturbances and vegetation distribution, but may also serve as a useful background for the management of the future forest landscape. Title: Characterization of fire effects on forest ecosystems in the Tillamook Forest, Oregon Author: Chen, Shu-Huei From the 1920's through 1951 several severe fires occurred in the predominantly conifer forest ecosystems of the northern Oregon Coast Range. Of the 211,151 ha. of mapped area, 57 percent was burned. The effects of frequent fires with high severity on forest ecosystems over time at the landscape level is not fully understood. A reconstruction of fire history was conducted to help investigate the effects of fire severity, frequency, and area extent on distribution of postfire tree regeneration, species composition, and stand tree size, as well as on current species composition and stand tree size. I hypothesized that: 1) vegetation patterns (1950's and 1988) would vary with time, because the persistence of disturbance effects (fire, logging, reforestation) on forest vegetative responses varied, and 2) environmental controls (topography, soil, climate) would become the primary influences when disturbance events were absent. In this study historical maps, sketches and notes were used to reconstruct spatial and temporal patterns of fires from the 1920's to 1951 and to identify unburned patches on a Geographic Information System. Relationships between fire regime and postfire and current vegetative patterns were tested. Constructing precise spatial data layers from early maps, produced before the availability of aerial photography or satellite image, was difficult. Historical map accuracy and quality were variable and poor by present day standards. Geographic reference points were used to transform inappropriate map scales. The reconstruction of spatial data was used to characterize spatial patterns of historic fires: my estimates of burn areas were similar to estimates in the literature. To reduce questionable data along fire and vegetation patch boundaries for hypothesis testing, an exclusion approach was used. Data within a 100 m width of fire and vegetation type boundary lines were called a fuzzy zone and removed from raw data. The distribution of various attributes in the reduced data was similar to the distribution of the complete data set. Regression analysis examined the effects of fire, logging, reforestation, topography, climate, and soil type on vegetation patterns. Patterns of postfire (1950's) species composition, tree regeneration and tree size (DBH) were associated with the effects of fires, as well as influences of logging and soil type. Indices of fire occurrences (reflecting the time variation and severity of fires) frequently correlated to the 1950's vegetation patterns. The number of fires (frequency) did not cause great differences in vegetation patterns. Current (1988) species composition and tree size (after absence of fire for more than three decades) were correlated more with terrain variables. Plant succession also influenced the current vegetation patterns. Neither the date or number of fires caused marked differences in distribution of species and tree size, except large conifers were found in areas missed by fires. Postfire and current vegetation patterns were correlated with soil types which reflect the influence of topographic and climatic characteristics. However, historic fires occurred frequently on some soil types. Fires have a confounding influence on soil type. This confounding influence of fire on soil type cannot be avoided. Reforestation efforts appeared to have little influence on the postfire and current vegetation patterns. I inferred that the short time period of reforestation effects did not show its importance on the 1950's vegetation landscape. Although regression analysis results did not support my hypothesis, by 1988, reforested area in the northern Coast Range had increased since 1950's. Most of the large fire-open patches became mixed forest in about 3 decades may still relate to the force of reforestation. On private unburned ownerships conifer forests in 1955 were subsequently cut and replaced by mostly mixed forest by 1988. The analysis supported the hypotheses that soil type, aspect and plant succession were dominant influences on current (1988) vegetation patterns, while forest disturbances such as fire and logging were important influences on the immediate postfire (1950's) patterns. The results not only interpret the relationship between historic disturbances and vegetation distribution, but may also serve as a useful background for the management of the future forest landscape. Close

• 47. [Article] Age structure, developmental pathways, and fire regime characterization of Douglas-fir/western hemlock forests in the central western Cascades of Oregon

  Descriptions of the fire regime in the Douglas-fir/western hemlock region of the Pacific Northwest traditionally have emphasized infrequent, predominantly stand-replacement fires and an associated linear ...

  Citation × Citation Citation Abstract Copy Title: Age structure, developmental pathways, and fire regime characterization of Douglas-fir/western hemlock forests in the central western Cascades of Oregon Author: Tepley, Alan J. Descriptions of the fire regime in the Douglas-fir/western hemlock region of the Pacific Northwest traditionally have emphasized infrequent, predominantly stand-replacement fires and an associated linear pathway of stand development, where all stands proceed along a common pathway until reset by the next fire. Although such a description may apply in wetter parts of the region, recent fire-history research suggests drier parts of the region support a mixed-severity regime, where most fires have substantial representation of all severity classes and most stands experience at least one non-stand-replacing fire between stand-replacement events. This study combines field and modeling approaches to better understand the complex fire regime in the central western Cascades of Oregon. Stand-structure data and ages of more than 3,000 trees were collected at 124 stands throughout two study areas with physiography representative of western and eastern portions of the western Cascade Range. Major objectives were to (1) develop a conceptual model of fire-mediated pathways of stand development, (2) determine the strengths of influences of topography on spatial variation in the fire regime, (3) provide a stronger understanding of modeling approaches commonly used to gain insight into historical landscape structure, and (4) develop methods to predict trajectories of change in landscape age structure under a non-stationary fire regime. In the study area, non-stand-replacing fire interspersed with infrequent, stand-replacement events led to a variety of even-aged and multi-cohort stands. The majority of stands (75%) had two or more age cohorts, where post-fire cohorts were dominated either by shade-intolerant species or shade-tolerant species, depending largely on fire severity. Age structure, used as a proxy for the cumulative effects of fire on stand development, showed a moderately strong relationship to topography overall, but relationships were strongest at both extremes of a continuum of the influences of fire frequency and severity on stand development and relatively weak in the middle. High topographic relief in the eastern part of the western Cascades may amplify variation in microclimate and fuel moisture, leading to a finer-scale spatial variation in fire spread and behavior, and thus a broader range of stand age structures and stronger fidelity of age structure to slope position and terrain shape in the deeply dissected terrain of the eastern part of the western Cascades than in the gentler terrain of the western part. In the modeling component of my research, I was able to use analytical procedures to reproduce much of the output provided by a stochastic, spatial simulation model previously applied to evaluate historical landscape structure of the Oregon Coast Range. The analytical approximation provides an explicit representation of the effects of input parameters and interactions among them. The increased transparency of model function given by such an analysis may facilitate communication of model output and uncertainty among ecologists and forest managers. Analytical modeling approaches were expanded to characterize trajectories of change in forest age structure in response to changes in the fire regime. Following a change in fire frequency, the proportion of the landscape covered by stands of a given age class is expected to change along a non-monotonic trajectory rather than transition directly to its equilibrium abundance under the new regime. Under some scenarios of change in fire frequency, the time for the expected age distribution of a landscape to converge to the equilibrium distribution of the new regime can be determined based only on the magnitude of change in fire frequency, regardless of the initial value or the direction of change. The theoretical modeling exercises provide insight into historical trends in the study area. Compiled across all sample sites, the age distribution of Douglas-fir trees was strongly bimodal. Peaks of establishment dates in the 16th and 19th centuries were synchronous between the two study areas, and each peak of Douglas-fir establishment coincides with one of the two periods of region-wide extensive fire identified in a previous synthesis of fire-history studies. The modeling exercises support the development of such a bimodal age distribution in response to centennial-scale changes in fire frequency, and they illustrate how the relative abundance of different stand-structure types may have varied over the last several centuries. Title: Age structure, developmental pathways, and fire regime characterization of Douglas-fir/western hemlock forests in the central western Cascades of Oregon Author: Tepley, Alan J. Descriptions of the fire regime in the Douglas-fir/western hemlock region of the Pacific Northwest traditionally have emphasized infrequent, predominantly stand-replacement fires and an associated linear pathway of stand development, where all stands proceed along a common pathway until reset by the next fire. Although such a description may apply in wetter parts of the region, recent fire-history research suggests drier parts of the region support a mixed-severity regime, where most fires have substantial representation of all severity classes and most stands experience at least one non-stand-replacing fire between stand-replacement events. This study combines field and modeling approaches to better understand the complex fire regime in the central western Cascades of Oregon. Stand-structure data and ages of more than 3,000 trees were collected at 124 stands throughout two study areas with physiography representative of western and eastern portions of the western Cascade Range. Major objectives were to (1) develop a conceptual model of fire-mediated pathways of stand development, (2) determine the strengths of influences of topography on spatial variation in the fire regime, (3) provide a stronger understanding of modeling approaches commonly used to gain insight into historical landscape structure, and (4) develop methods to predict trajectories of change in landscape age structure under a non-stationary fire regime. In the study area, non-stand-replacing fire interspersed with infrequent, stand-replacement events led to a variety of even-aged and multi-cohort stands. The majority of stands (75%) had two or more age cohorts, where post-fire cohorts were dominated either by shade-intolerant species or shade-tolerant species, depending largely on fire severity. Age structure, used as a proxy for the cumulative effects of fire on stand development, showed a moderately strong relationship to topography overall, but relationships were strongest at both extremes of a continuum of the influences of fire frequency and severity on stand development and relatively weak in the middle. High topographic relief in the eastern part of the western Cascades may amplify variation in microclimate and fuel moisture, leading to a finer-scale spatial variation in fire spread and behavior, and thus a broader range of stand age structures and stronger fidelity of age structure to slope position and terrain shape in the deeply dissected terrain of the eastern part of the western Cascades than in the gentler terrain of the western part. In the modeling component of my research, I was able to use analytical procedures to reproduce much of the output provided by a stochastic, spatial simulation model previously applied to evaluate historical landscape structure of the Oregon Coast Range. The analytical approximation provides an explicit representation of the effects of input parameters and interactions among them. The increased transparency of model function given by such an analysis may facilitate communication of model output and uncertainty among ecologists and forest managers. Analytical modeling approaches were expanded to characterize trajectories of change in forest age structure in response to changes in the fire regime. Following a change in fire frequency, the proportion of the landscape covered by stands of a given age class is expected to change along a non-monotonic trajectory rather than transition directly to its equilibrium abundance under the new regime. Under some scenarios of change in fire frequency, the time for the expected age distribution of a landscape to converge to the equilibrium distribution of the new regime can be determined based only on the magnitude of change in fire frequency, regardless of the initial value or the direction of change. The theoretical modeling exercises provide insight into historical trends in the study area. Compiled across all sample sites, the age distribution of Douglas-fir trees was strongly bimodal. Peaks of establishment dates in the 16th and 19th centuries were synchronous between the two study areas, and each peak of Douglas-fir establishment coincides with one of the two periods of region-wide extensive fire identified in a previous synthesis of fire-history studies. The modeling exercises support the development of such a bimodal age distribution in response to centennial-scale changes in fire frequency, and they illustrate how the relative abundance of different stand-structure types may have varied over the last several centuries. Close

• 48. [Article] Long and Short-Term Effects of Fire on Soil Charcoal of a Conifer Forest in Southwest Oregon

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Multidisciplinary ...

  Citation × Citation Citation Abstract Copy Title: Long and Short-Term Effects of Fire on Soil Charcoal of a Conifer Forest in Southwest Oregon Author: Darbyshire, Robyn, Morrissette, Brett, Pingree, Melissa R. A., Homann, Peter S. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Multidisciplinary Digital Publishing Institute and can be found at: [link to http://www.mdpi.com/. Title: Long and Short-Term Effects of Fire on Soil Charcoal of a Conifer Forest in Southwest Oregon Author: Darbyshire, Robyn, Morrissette, Brett, Pingree, Melissa R. A., Homann, Peter S. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Multidisciplinary Digital Publishing Institute and can be found at: [link to http://www.mdpi.com/. Close

• 49. [Article] Report of the forest fuels and hazard mitigation committee to the Oregon Department of Forestry and Oregon Fire Program Review

  Many Oregon communities face serious and growing risks from wildfires. These fires are increasingly large and severe after many decades of fire suppression and land use changes, flammable fuel buildups ...

  Citation × Citation Citation Abstract Copy Title: Report of the forest fuels and hazard mitigation committee to the Oregon Department of Forestry and Oregon Fire Program Review Author: Institute for Natural Resources, Behan, Jeff, Lynn, Kathy Many Oregon communities face serious and growing risks from wildfires. These fires are increasingly large and severe after many decades of fire suppression and land use changes, flammable fuel buildups and interactions with climate. The wildland-urban interface (WUI) continues to expand as people relocate to rural areas where they often expect structural fire protection similar to what they experienced in cities. But conditions are different in rural communities located in fire-prone forests. The risk of severe wildfire is greater and limited resources are available to deal with severe fires when they break out. Fire prevention and suppression without vegetation management to reduce accumulated fuels has and will result in a continuation of uncharacteristically severe, stand-replacing wildfires, particularly in eastern and southwestern Oregon. These fires are difficult and expensive to control. They also place firefighters at high risk. Federal, state and rural fire protection agencies are struggling to cope as wildfire threats, costs, and the scope of protection responsibilities continue to increase. Federal agencies have initiated efforts to reduce hazardous fuels and increase community wildfire readiness as directed by the 2000 National Fire Plan (NFP) and 2003 Healthy Forests Restoration Act (HFRA). These mandates are now being implemented at multiple levels with every effort to coordinate for greater efficiency. As part of the 2004 Oregon Fire Program Review, the Oregon Department of Forestry (ODF) formed the Forest Fuels and Hazard Mitigation (FFHM) Committee to assess hazardous fuel loading issues, and recommend ways to reduce risk, and improve and strengthen the multiple hazard mitigation strategies in Oregon. Title: Report of the forest fuels and hazard mitigation committee to the Oregon Department of Forestry and Oregon Fire Program Review Author: Institute for Natural Resources, Behan, Jeff, Lynn, Kathy Many Oregon communities face serious and growing risks from wildfires. These fires are increasingly large and severe after many decades of fire suppression and land use changes, flammable fuel buildups and interactions with climate. The wildland-urban interface (WUI) continues to expand as people relocate to rural areas where they often expect structural fire protection similar to what they experienced in cities. But conditions are different in rural communities located in fire-prone forests. The risk of severe wildfire is greater and limited resources are available to deal with severe fires when they break out. Fire prevention and suppression without vegetation management to reduce accumulated fuels has and will result in a continuation of uncharacteristically severe, stand-replacing wildfires, particularly in eastern and southwestern Oregon. These fires are difficult and expensive to control. They also place firefighters at high risk. Federal, state and rural fire protection agencies are struggling to cope as wildfire threats, costs, and the scope of protection responsibilities continue to increase. Federal agencies have initiated efforts to reduce hazardous fuels and increase community wildfire readiness as directed by the 2000 National Fire Plan (NFP) and 2003 Healthy Forests Restoration Act (HFRA). These mandates are now being implemented at multiple levels with every effort to coordinate for greater efficiency. As part of the 2004 Oregon Fire Program Review, the Oregon Department of Forestry (ODF) formed the Forest Fuels and Hazard Mitigation (FFHM) Committee to assess hazardous fuel loading issues, and recommend ways to reduce risk, and improve and strengthen the multiple hazard mitigation strategies in Oregon. Close

• 50. [Article] Chaparral history, dynamics, and response to disturbance in southwest Oregon : insights from age structure

  Fuels management on Bureau of Land Management lands in SW Oregon, USA, is motivated by the needs to reduce fire hazard and restore ecosystems thought to be impacted by fire suppression. Chaparral is one ...

  Citation × Citation Citation Abstract Copy Title: Chaparral history, dynamics, and response to disturbance in southwest Oregon : insights from age structure Author: Duren, Olivia Fuels management on Bureau of Land Management lands in SW Oregon, USA, is motivated by the needs to reduce fire hazard and restore ecosystems thought to be impacted by fire suppression. Chaparral is one of the most characteristic vegetation communities of SW Oregon's interior valleys, and extensive acreages within this system are targeted annually for fuels treatment. However, this community is also poorly understood. Little is known about its response to fire suppression, and the assumptions justifying the need for fuels reduction and on which treatment prescriptions are based are extrapolations from other ecosystems. I studied patterns in chaparral age structure of two obligate-seeding shrubs, Arctostaphylos viscida C. Parry and Ceanothus cuneatus (Hook.) Nutt., for insights into the influences of environment and the two dominant disturbances in SW Oregon, fire and grazing, on population structure and dynamics. My 31 low to mid-elevation study sites represent four chaparral 'types' and a range in times since fire (22 yr to > 114 yr). My study area is near the northernmost extension of the California chaparral vegetation type, and results indicate that SW Oregon chaparral populations diverge from studied California chaparral populations in several fundamental ways. All stands unburned for > 30 yr were uneven-aged due to prolific recruitment in the absence of fire and appreciable fire survivorship. Relatively high shrub densities were associated with even-aged sites, but these sites were all young (< 30 yr) and density declined the longer stands were unburned. No relationships were detected between site environment or disturbance history and age structure in general, or the relative amount of fire-free recruitment or fire survivorship in particular. Results suggest that most, if not all, chaparral stands would over time develop uneven-aged structure across the range of environments represented in the study area. Current fuels treatment prescriptions in SW Oregon chaparral are predicated on the assumption that fire suppression has replaced naturally high-frequency, low-severity fires with less frequent and higher-severity fires due to an unnatural accumulation of fuels. However, it appears that this model is not appropriate for chaparral vegetation. Chaparral has apparently experienced a fire regime that is distinct from that of adjacent vegetation communities, and fire suppression does not appear to have altered overall chaparral structure or fire severity. Current fuels treatments are unlikely to reproduce stand structures observed in mature chaparral or in post-wildfire stands. Rather, fuels treatments are likely to alter the trajectory of chaparral development that appears to have been in place for the last century. Results clearly illuminate that chaparral encompasses a wide range of structures and responses to environment and disturbance, and imply that precepts of chaparral ecology and management should be tailored on a geographic basis. Results also underscore the need for management objectives to recognize differences among vegetation communities in complex environments. Title: Chaparral history, dynamics, and response to disturbance in southwest Oregon : insights from age structure Author: Duren, Olivia Fuels management on Bureau of Land Management lands in SW Oregon, USA, is motivated by the needs to reduce fire hazard and restore ecosystems thought to be impacted by fire suppression. Chaparral is one of the most characteristic vegetation communities of SW Oregon's interior valleys, and extensive acreages within this system are targeted annually for fuels treatment. However, this community is also poorly understood. Little is known about its response to fire suppression, and the assumptions justifying the need for fuels reduction and on which treatment prescriptions are based are extrapolations from other ecosystems. I studied patterns in chaparral age structure of two obligate-seeding shrubs, Arctostaphylos viscida C. Parry and Ceanothus cuneatus (Hook.) Nutt., for insights into the influences of environment and the two dominant disturbances in SW Oregon, fire and grazing, on population structure and dynamics. My 31 low to mid-elevation study sites represent four chaparral 'types' and a range in times since fire (22 yr to > 114 yr). My study area is near the northernmost extension of the California chaparral vegetation type, and results indicate that SW Oregon chaparral populations diverge from studied California chaparral populations in several fundamental ways. All stands unburned for > 30 yr were uneven-aged due to prolific recruitment in the absence of fire and appreciable fire survivorship. Relatively high shrub densities were associated with even-aged sites, but these sites were all young (< 30 yr) and density declined the longer stands were unburned. No relationships were detected between site environment or disturbance history and age structure in general, or the relative amount of fire-free recruitment or fire survivorship in particular. Results suggest that most, if not all, chaparral stands would over time develop uneven-aged structure across the range of environments represented in the study area. Current fuels treatment prescriptions in SW Oregon chaparral are predicated on the assumption that fire suppression has replaced naturally high-frequency, low-severity fires with less frequent and higher-severity fires due to an unnatural accumulation of fuels. However, it appears that this model is not appropriate for chaparral vegetation. Chaparral has apparently experienced a fire regime that is distinct from that of adjacent vegetation communities, and fire suppression does not appear to have altered overall chaparral structure or fire severity. Current fuels treatments are unlikely to reproduce stand structures observed in mature chaparral or in post-wildfire stands. Rather, fuels treatments are likely to alter the trajectory of chaparral development that appears to have been in place for the last century. Results clearly illuminate that chaparral encompasses a wide range of structures and responses to environment and disturbance, and imply that precepts of chaparral ecology and management should be tailored on a geographic basis. Results also underscore the need for management objectives to recognize differences among vegetation communities in complex environments. Close