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• 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