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• 1. [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

• 2. [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

• 3. [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

• 4. [Article] Dead fuels and understory vegetation six years after a large mixed-severity wildfire in southwest Oregon

  Though the mixed-evergreen forests of the Klamath Siskiyous have a long history of large, mixed-severity fires, most research in this region has concentrated on the impacts of high-severity fire. Knowledge ...

  Citation × Citation Citation Abstract Copy Title: Dead fuels and understory vegetation six years after a large mixed-severity wildfire in southwest Oregon Author: Nathanson, Amy Though the mixed-evergreen forests of the Klamath Siskiyous have a long history of large, mixed-severity fires, most research in this region has concentrated on the impacts of high-severity fire. Knowledge of the ecological effects of low- and moderate-severity areas within mixed-severity fires is important because such areas may account for over half the landscape affected by a fire. The purpose of this study was to understand the relationship of fire severity with dead fuels and understory vegetation across a full range of fire severities. Study sites were located within and just outside the boundary of the 2002 Biscuit Fire, which burned 200,000 hectares in a mosaic of burn severities. Six years after the Biscuit Fire, the biomass and depth of litter and duff was lower on burned sites than unburned sites, and lowest on high-severity sites. This relationship was reversed for woody fuels >7.62 cm in diameter, where quantities were highest in high- and extreme-severity areas, though there was no evidence that quantities differed between low-severity and unburned sites. There was no evidence of a relationship between woody fuels 0.64-7.62 cm in diameter and fire severity, 6 years post-fire. There was no evidence that fuel quantities differed between sites that burned only in the Biscuit Fire with sites that also burned 15 years earlier in the 1987 Silver Fire. Fuel quantities and composition differed between burned and unburned sites, but these differences disappeared if litter and duff were not considered. Fuel classes were correlated with each other within three general size classes: small (litter, duff, and fuels <2.54 cm), medium (fuels 2.54-30 cm), and large (fuels >30 cm). There was little correlation between these size classes. Vegetation response also varied by fire severity, species, and height. Generally, density for tree seedlings <0.5 m was highest on low-severity sites and lowest on high-severity sites. For seedlings 0.5-1.37 m the relationship was reversed, with the highest seedling densities in high-severity areas. Specific seedling relationships to burn severity and other explanatory factors (e.g. shrub cover, elevation, precipitation, maxiumun August temperatures) varied by species and seedling height. Average seedling densities were above the minimum acceptable stocking levels of 333 trees per hectare (135 seedlings/acre) as identified in federal plans for the fire area. Shrub species richness and diversity did not vary with burn severity; however, shrub species and ground cover composition did differ with burn severity six years after the Biscuit Fire. The relationship of understory cover composition with burn severity aligned with species life history traits; fire-adapted, nitrogen-fixing species were more prevalent on high- and extreme-severity sites while species associated with low-severity fire or old-growth forests were more prevalent on low-severity or unburned sites. I found no evidence of difference in total graminoid or forb cover based on fire severity, but shrub quantities were lower on low-severity sites than on unburned, high-, and extreme-severity sites. This study reveals how fuel and vegetation vary across the full range of fire severities. It demonstrates that mixed-severity fires create a mix of ecological responses. It also provides a baseline for future studies, as the relationships between fire severity and fuels or vegetation may disappear or change in subsequent decades. Title: Dead fuels and understory vegetation six years after a large mixed-severity wildfire in southwest Oregon Author: Nathanson, Amy Though the mixed-evergreen forests of the Klamath Siskiyous have a long history of large, mixed-severity fires, most research in this region has concentrated on the impacts of high-severity fire. Knowledge of the ecological effects of low- and moderate-severity areas within mixed-severity fires is important because such areas may account for over half the landscape affected by a fire. The purpose of this study was to understand the relationship of fire severity with dead fuels and understory vegetation across a full range of fire severities. Study sites were located within and just outside the boundary of the 2002 Biscuit Fire, which burned 200,000 hectares in a mosaic of burn severities. Six years after the Biscuit Fire, the biomass and depth of litter and duff was lower on burned sites than unburned sites, and lowest on high-severity sites. This relationship was reversed for woody fuels >7.62 cm in diameter, where quantities were highest in high- and extreme-severity areas, though there was no evidence that quantities differed between low-severity and unburned sites. There was no evidence of a relationship between woody fuels 0.64-7.62 cm in diameter and fire severity, 6 years post-fire. There was no evidence that fuel quantities differed between sites that burned only in the Biscuit Fire with sites that also burned 15 years earlier in the 1987 Silver Fire. Fuel quantities and composition differed between burned and unburned sites, but these differences disappeared if litter and duff were not considered. Fuel classes were correlated with each other within three general size classes: small (litter, duff, and fuels <2.54 cm), medium (fuels 2.54-30 cm), and large (fuels >30 cm). There was little correlation between these size classes. Vegetation response also varied by fire severity, species, and height. Generally, density for tree seedlings <0.5 m was highest on low-severity sites and lowest on high-severity sites. For seedlings 0.5-1.37 m the relationship was reversed, with the highest seedling densities in high-severity areas. Specific seedling relationships to burn severity and other explanatory factors (e.g. shrub cover, elevation, precipitation, maxiumun August temperatures) varied by species and seedling height. Average seedling densities were above the minimum acceptable stocking levels of 333 trees per hectare (135 seedlings/acre) as identified in federal plans for the fire area. Shrub species richness and diversity did not vary with burn severity; however, shrub species and ground cover composition did differ with burn severity six years after the Biscuit Fire. The relationship of understory cover composition with burn severity aligned with species life history traits; fire-adapted, nitrogen-fixing species were more prevalent on high- and extreme-severity sites while species associated with low-severity fire or old-growth forests were more prevalent on low-severity or unburned sites. I found no evidence of difference in total graminoid or forb cover based on fire severity, but shrub quantities were lower on low-severity sites than on unburned, high-, and extreme-severity sites. This study reveals how fuel and vegetation vary across the full range of fire severities. It demonstrates that mixed-severity fires create a mix of ecological responses. It also provides a baseline for future studies, as the relationships between fire severity and fuels or vegetation may disappear or change in subsequent decades. Close

• 5. [Article] Carbon dynamics following landscape fire: influence of burn severity, climate, and stand history in the Metolius Watershed, Oregon

  Fire is a fundamental disturbance that drives terrestrial and atmospheric carbon dynamics. Previous studies have quantified fire effects on carbon cycling from local to global scales but have focused ...

  Citation × Citation Citation Abstract Copy Title: Carbon dynamics following landscape fire: influence of burn severity, climate, and stand history in the Metolius Watershed, Oregon Author: Meigs, Garrett W. Fire is a fundamental disturbance that drives terrestrial and atmospheric carbon dynamics. Previous studies have quantified fire effects on carbon cycling from local to global scales but have focused nearly exclusively on high-severity, stand-replacement fire. Since 2002, variable-severity wildfires have burned more than 65 000 ha across the east slope of the Oregon Cascades, including 4 large fires that burned ca. 50% of the forested area within the Metolius Watershed in 2002 and 2003. This thesis integrates data from 64 field plots, remote-sensing, and an ecosystem process model to investigate the effects of low-, moderate-, and high-severity fire. The primary research objectives were to: (a) quantify combustion and mortality effects on carbon pools, postfire net ecosystem production (NEP), and potential regeneration trajectories at the stand scale; (b) introduce novel remote-sensing datasets into a modeling framework to assess the importance of low- and moderate-severity fire across the landscape and region. At the stand-scale, the 3 levels of burn severity (overstory tree mortality) resulted in profoundly different impacts on combustion, mortality, postfire carbon balance, and potential regeneration trajectories. Simulated combustion ranged from 16.6 to 32.3 Mg C ha-1, or 13% to 35% of prefire aboveground carbon. C transfers from fire-induced tree mortality were larger in magnitude than combustion, as live aboveground C decreased by >90% from low- to high-severity stands. Despite this decline, total net primary productivity (NPP) was only 40% lower in high- vs. low-severity stands, reflecting a compensatory effect of non-tree NPP. Dead wood respiratory losses were small relative to C uptake (range: 10-35% of total NPP), suggesting important decomposition lags in this seasonally-arid system. Although soil C, soil respiration, and fine root NPP were conserved across severity classes, NEP declined with increasing severity, driven by trends in aboveground NPP. Postfire conifer seedling density was generally abundant and varied over 5 orders of magnitude (study-wide median: 812, range: 0 – 62 134 seedlings ha-1). Seedling density was negatively correlated with overstory mortality, whereas shrub biomass showed the opposite response, indicating a wide range of potential successional trajectories. Despite substantial combustion and mortality effects on carbon pools and fluxes, the rapid response of postfire vegetation, coupled with conservation of belowground processes, may offset long-term declines in carbon storage, indicating a surprising degree of postfire stability. These stand-scale results describe a broad range of fire effects—a high degree of pyrodiversity—but because burn severity was not evenly distributed across space, the landscape-level fire effects depend on the severity mosaic. At the landscape-scale, moderate- and low-severity fire contributed 25% and 11% of total estimated pyrogenic carbon emission, respectively (0.66 Tg C total, or ca. 2.2% of statewide anthropogenic CO2 emissions equivalent from the same 2-year period). Moderate- and low-severity fire accounted for 23% and 5% of landscape-level tree mortality, respectively, which resulted in the transfer of 2.00 Tg C from live to dead pools. This carbon transfer was ca. 3-fold higher than the one-time pulse from pyrogenic emission, but it will likely take decades for this dead wood to decompose via heterotrophic respiration. The inclusion of moderate-severity fire reduced postfire (2004) mean annual NEP by 39% compared to the high-severity only scenario; low-severity fire influence on NEP was small (additional reduction of 11% in mean NEP), likely because of high tree survivorship and the relatively lower areal coverage of low-severity fire. One year postfire, burned areas were a strong C source (net C exchange across 53 000 ha: -0.065 Tg C y-1; mean ± SD: -123 ± 110 g C m-2 y-1) vs. a prefire mean near C neutral (1997-2001 mean NEP ± SD: -5 ± 51 g C m-2 y-1). The model has been known to underestimate carbon uptake in mature and old semi-arid forests, so the prefire value is likely underestimated. Despite the resurgence of wildfire across western North America, including a substantial increase in the proportion of high-severity fire in the ecoregions studied here, low- and moderate-severity wildfire accounts for the majority of burned area in the Pacific Northwest region. This non-stand-replacement fire has important consequences for carbon loss and uptake at landscape- and regional-scales. The results from this thesis suggest that by accounting for the full gradient of fire effects, carbon modelers can substantially reduce uncertainties in key components of regional and global carbon budgets, particularly pyrogenic emissions, mortality, and NEP. Understanding the effects of disturbance variability on terrestrial carbon cycling will become increasingly important in the context of emerging regional and global carbon policies. Title: Carbon dynamics following landscape fire: influence of burn severity, climate, and stand history in the Metolius Watershed, Oregon Author: Meigs, Garrett W. Fire is a fundamental disturbance that drives terrestrial and atmospheric carbon dynamics. Previous studies have quantified fire effects on carbon cycling from local to global scales but have focused nearly exclusively on high-severity, stand-replacement fire. Since 2002, variable-severity wildfires have burned more than 65 000 ha across the east slope of the Oregon Cascades, including 4 large fires that burned ca. 50% of the forested area within the Metolius Watershed in 2002 and 2003. This thesis integrates data from 64 field plots, remote-sensing, and an ecosystem process model to investigate the effects of low-, moderate-, and high-severity fire. The primary research objectives were to: (a) quantify combustion and mortality effects on carbon pools, postfire net ecosystem production (NEP), and potential regeneration trajectories at the stand scale; (b) introduce novel remote-sensing datasets into a modeling framework to assess the importance of low- and moderate-severity fire across the landscape and region. At the stand-scale, the 3 levels of burn severity (overstory tree mortality) resulted in profoundly different impacts on combustion, mortality, postfire carbon balance, and potential regeneration trajectories. Simulated combustion ranged from 16.6 to 32.3 Mg C ha-1, or 13% to 35% of prefire aboveground carbon. C transfers from fire-induced tree mortality were larger in magnitude than combustion, as live aboveground C decreased by >90% from low- to high-severity stands. Despite this decline, total net primary productivity (NPP) was only 40% lower in high- vs. low-severity stands, reflecting a compensatory effect of non-tree NPP. Dead wood respiratory losses were small relative to C uptake (range: 10-35% of total NPP), suggesting important decomposition lags in this seasonally-arid system. Although soil C, soil respiration, and fine root NPP were conserved across severity classes, NEP declined with increasing severity, driven by trends in aboveground NPP. Postfire conifer seedling density was generally abundant and varied over 5 orders of magnitude (study-wide median: 812, range: 0 – 62 134 seedlings ha-1). Seedling density was negatively correlated with overstory mortality, whereas shrub biomass showed the opposite response, indicating a wide range of potential successional trajectories. Despite substantial combustion and mortality effects on carbon pools and fluxes, the rapid response of postfire vegetation, coupled with conservation of belowground processes, may offset long-term declines in carbon storage, indicating a surprising degree of postfire stability. These stand-scale results describe a broad range of fire effects—a high degree of pyrodiversity—but because burn severity was not evenly distributed across space, the landscape-level fire effects depend on the severity mosaic. At the landscape-scale, moderate- and low-severity fire contributed 25% and 11% of total estimated pyrogenic carbon emission, respectively (0.66 Tg C total, or ca. 2.2% of statewide anthropogenic CO2 emissions equivalent from the same 2-year period). Moderate- and low-severity fire accounted for 23% and 5% of landscape-level tree mortality, respectively, which resulted in the transfer of 2.00 Tg C from live to dead pools. This carbon transfer was ca. 3-fold higher than the one-time pulse from pyrogenic emission, but it will likely take decades for this dead wood to decompose via heterotrophic respiration. The inclusion of moderate-severity fire reduced postfire (2004) mean annual NEP by 39% compared to the high-severity only scenario; low-severity fire influence on NEP was small (additional reduction of 11% in mean NEP), likely because of high tree survivorship and the relatively lower areal coverage of low-severity fire. One year postfire, burned areas were a strong C source (net C exchange across 53 000 ha: -0.065 Tg C y-1; mean ± SD: -123 ± 110 g C m-2 y-1) vs. a prefire mean near C neutral (1997-2001 mean NEP ± SD: -5 ± 51 g C m-2 y-1). The model has been known to underestimate carbon uptake in mature and old semi-arid forests, so the prefire value is likely underestimated. Despite the resurgence of wildfire across western North America, including a substantial increase in the proportion of high-severity fire in the ecoregions studied here, low- and moderate-severity wildfire accounts for the majority of burned area in the Pacific Northwest region. This non-stand-replacement fire has important consequences for carbon loss and uptake at landscape- and regional-scales. The results from this thesis suggest that by accounting for the full gradient of fire effects, carbon modelers can substantially reduce uncertainties in key components of regional and global carbon budgets, particularly pyrogenic emissions, mortality, and NEP. Understanding the effects of disturbance variability on terrestrial carbon cycling will become increasingly important in the context of emerging regional and global carbon policies. Close

• 6. [Article] Bridging the worlds of fire managers and researchers: Lessons and opportunities from the Wildland Fire Workshops

  In March and April of 2003, over 250 managers, researchers, and other participants gathered for a series of workshops at Oregon State University, the University of Arizona, and Colorado State University, ...

  Citation × Citation Citation Abstract Copy Title: Bridging the worlds of fire managers and researchers: Lessons and opportunities from the Wildland Fire Workshops Author: White, Seth M. In March and April of 2003, over 250 managers, researchers, and other participants gathered for a series of workshops at Oregon State University, the University of Arizona, and Colorado State University, near the largest wildfires of 2002. In response to the need for better understanding of large fires, the Wildland Fire Workshops were designed to create an atmosphere for quality interactions between managers and researchers and to accomplish the following objectives: (1) create a prioritized list of recommendations for future wildland fire research; (2) identify the characteristics of effective partnerships; (3) identify types of effective information, tools, and processes; and (4) evaluate the workshops as a potential blueprint for similar workshops in other regions. Through a series of professionally facilitated workshops, participants worked toward speaking with one voice about many key issues. Although differences emerged among individuals, disciplines, and geographic locations, many common themes emerged. Participants suggested that research should be framed in the larger picture of fire ecology and ecosystem restoration, be interdisciplinary, be attentive to the effects of fire at different scales over the landscape and through time, and be focused on social issues. Effective partnerships occur when direct interaction takes place between people at multiple stages, adequate time is allowed for partnership building, partners are rewarded and held accountable for their roles, and when dedicated individuals are identified and cultivated. Participants identified effective information, tools, and processes as those that are adequately and consistently funded, user-friendly, interactive between people at multiple levels, and often championed by key, dedicated individuals. A survey of participants at the final meeting in Colorado revealed that the workshops did in fact create an atmosphere for positive interactions between managers and researchers, and that with some refinements, similar workshops could be carried out in other regions with productive results. Title: Bridging the worlds of fire managers and researchers: Lessons and opportunities from the Wildland Fire Workshops Author: White, Seth M. In March and April of 2003, over 250 managers, researchers, and other participants gathered for a series of workshops at Oregon State University, the University of Arizona, and Colorado State University, near the largest wildfires of 2002. In response to the need for better understanding of large fires, the Wildland Fire Workshops were designed to create an atmosphere for quality interactions between managers and researchers and to accomplish the following objectives: (1) create a prioritized list of recommendations for future wildland fire research; (2) identify the characteristics of effective partnerships; (3) identify types of effective information, tools, and processes; and (4) evaluate the workshops as a potential blueprint for similar workshops in other regions. Through a series of professionally facilitated workshops, participants worked toward speaking with one voice about many key issues. Although differences emerged among individuals, disciplines, and geographic locations, many common themes emerged. Participants suggested that research should be framed in the larger picture of fire ecology and ecosystem restoration, be interdisciplinary, be attentive to the effects of fire at different scales over the landscape and through time, and be focused on social issues. Effective partnerships occur when direct interaction takes place between people at multiple stages, adequate time is allowed for partnership building, partners are rewarded and held accountable for their roles, and when dedicated individuals are identified and cultivated. Participants identified effective information, tools, and processes as those that are adequately and consistently funded, user-friendly, interactive between people at multiple levels, and often championed by key, dedicated individuals. A survey of participants at the final meeting in Colorado revealed that the workshops did in fact create an atmosphere for positive interactions between managers and researchers, and that with some refinements, similar workshops could be carried out in other regions with productive results. Close

• 7. [Article] Potential effects of climate change and fire management on fire behavior and vegetation patterns on an east Cascades landscape

  Climate exerts considerable control on wildfire regimes, and climate and wildfire are both major drivers of forest growth and succession in interior Northwest forests. Estimating potential response of ...

  Citation × Citation Citation Abstract Copy Title: Potential effects of climate change and fire management on fire behavior and vegetation patterns on an east Cascades landscape Author: Greaves, Heather E. Climate exerts considerable control on wildfire regimes, and climate and wildfire are both major drivers of forest growth and succession in interior Northwest forests. Estimating potential response of these landscapes to anticipated changes in climate helps researchers and land managers understand and mitigate impacts of climate change on important ecological and economic resources. Spatially explicit, mechanistic computer simulation models are powerful tools that permit researchers to incorporate climate and disturbance events along with vegetation physiology and phenology to explore complex potential effects of climate change over wide spatial and temporal scales. In this thesis, I used the simulation model FireBGCv2 to characterize potential response of fire, vegetation, and landscape dynamics to a range of possible future climate and fire management scenarios. The simulation landscape (~43,000 hectares) is part of Deschutes National Forest, which is located at the interface of maritime and continental climates and is known for its beauty and ecological diversity. Simulation scenarios included all combinations of +0°C, +3°C, and +6°C of warming; +10%, ±0%, and -10% historical precipitation; and 10% and 90% fire suppression, and were run for 500 years. To characterize fire dynamics, I investigated how mean fire frequency, intensity, and fuel loadings changed over time in all scenarios, and how fire and tree mortality interacted over time. To explore vegetation and landscape dynamics, I described the distribution and spatial arrangement of vegetation types and forest successional stages on the landscape, and used a nonmetric multidimensional scaling (NMS) ordination to holistically evaluate overall similarity of composition, structure, and landscape pattern among all simulation scenarios over time. Changes in precipitation had little effect on fire characteristics or vegetation and landscape characteristics, indicating that simulated precipitation changes were not sufficient to significantly affect vegetation moisture stress or fire behavior on this landscape. Current heavy fuel loads controlled early fire dynamics, with high mean fire intensities occurring early in all simulations. Increases in fire frequency accompanied all temperature increases, leading to decreasing fuel loads and fire intensities over time in warming scenarios. With no increase in temperature or in fire frequency, high fire intensities and heavier fuel loads were sustained. Over time, more fire associated with warming or less fire suppression increased the percentage of the landscape occupied by non-forest and fire-sensitive early seral forest successional stages, which tended to increase the percentage of fire area burning at high severity (in terms of tree mortality). This fire-vegetation relationship may reflect a return to a more historical range of conditions on this landscape. Higher temperatures and fire frequency led to significant spatial migration of forest types across the landscape, with communities at the highest and lowest elevations particularly affected. Warming led to an upslope shift of warm mixed conifer and ponderosa pine (Pinus ponderosa) forests, severely contracting (under 3° of warming) or eliminating (under 6° of warming) area dominated by mountain hemlock (Tsuga mertensiana) and cool, wet conifer forest in the high western portion of the landscape. In lower elevations, warming and fire together contributed to significant expansion of open (<10% tree canopy cover) forest and grass- and shrubland. The compositional changes and spatial shifts simulated in the warming scenarios suggest that climate change is likely to significantly affect forests on this landscape. Warming and associated fire also tended to increase heterogeneity of forest structural stages and landscape pattern, resulting in a more diverse distribution of structural stages, especially in lower elevations, and a more divided landscape of smaller forest stands. The NMS ordination emphasized the dissimilarity between the severe +6° scenarios and the other two temperature scenarios. The +0° and +3° scenarios differed from each other in composition (mainly because cool forest was lost in the +3° scenarios), but within a given level of fire suppression they remained remarkably similar in terms of overall composition, structure, and landscape pattern, while the +6° scenarios separated noticeably from them. Such decisive differences suggest that under the simulated ranges of precipitation and fire suppression, the interval between 3 and 6 degrees of warming on this landscape may capture an ecological threshold, or tipping point. Additional simulation research that incorporates (for example) management actions, insects and pathogens, and a wider array of precipitation scenarios could help illuminate more clearly the possible range of future landscape conditions. Still, these results provide a glimpse of potential divergent outcomes on this important landscape under possible future climates, and suggest that these forests will undergo considerable changes from both historical and current conditions in response to higher temperatures expected in this area. Some changes may be inevitable with warming, such as the upslope shift of warm forest types, but careful planning for fire and fuels management might allow land managers to modulate fire behavior and steer vegetation dynamics toward the most desirable outcome possible. Title: Potential effects of climate change and fire management on fire behavior and vegetation patterns on an east Cascades landscape Author: Greaves, Heather E. Climate exerts considerable control on wildfire regimes, and climate and wildfire are both major drivers of forest growth and succession in interior Northwest forests. Estimating potential response of these landscapes to anticipated changes in climate helps researchers and land managers understand and mitigate impacts of climate change on important ecological and economic resources. Spatially explicit, mechanistic computer simulation models are powerful tools that permit researchers to incorporate climate and disturbance events along with vegetation physiology and phenology to explore complex potential effects of climate change over wide spatial and temporal scales. In this thesis, I used the simulation model FireBGCv2 to characterize potential response of fire, vegetation, and landscape dynamics to a range of possible future climate and fire management scenarios. The simulation landscape (~43,000 hectares) is part of Deschutes National Forest, which is located at the interface of maritime and continental climates and is known for its beauty and ecological diversity. Simulation scenarios included all combinations of +0°C, +3°C, and +6°C of warming; +10%, ±0%, and -10% historical precipitation; and 10% and 90% fire suppression, and were run for 500 years. To characterize fire dynamics, I investigated how mean fire frequency, intensity, and fuel loadings changed over time in all scenarios, and how fire and tree mortality interacted over time. To explore vegetation and landscape dynamics, I described the distribution and spatial arrangement of vegetation types and forest successional stages on the landscape, and used a nonmetric multidimensional scaling (NMS) ordination to holistically evaluate overall similarity of composition, structure, and landscape pattern among all simulation scenarios over time. Changes in precipitation had little effect on fire characteristics or vegetation and landscape characteristics, indicating that simulated precipitation changes were not sufficient to significantly affect vegetation moisture stress or fire behavior on this landscape. Current heavy fuel loads controlled early fire dynamics, with high mean fire intensities occurring early in all simulations. Increases in fire frequency accompanied all temperature increases, leading to decreasing fuel loads and fire intensities over time in warming scenarios. With no increase in temperature or in fire frequency, high fire intensities and heavier fuel loads were sustained. Over time, more fire associated with warming or less fire suppression increased the percentage of the landscape occupied by non-forest and fire-sensitive early seral forest successional stages, which tended to increase the percentage of fire area burning at high severity (in terms of tree mortality). This fire-vegetation relationship may reflect a return to a more historical range of conditions on this landscape. Higher temperatures and fire frequency led to significant spatial migration of forest types across the landscape, with communities at the highest and lowest elevations particularly affected. Warming led to an upslope shift of warm mixed conifer and ponderosa pine (Pinus ponderosa) forests, severely contracting (under 3° of warming) or eliminating (under 6° of warming) area dominated by mountain hemlock (Tsuga mertensiana) and cool, wet conifer forest in the high western portion of the landscape. In lower elevations, warming and fire together contributed to significant expansion of open (<10% tree canopy cover) forest and grass- and shrubland. The compositional changes and spatial shifts simulated in the warming scenarios suggest that climate change is likely to significantly affect forests on this landscape. Warming and associated fire also tended to increase heterogeneity of forest structural stages and landscape pattern, resulting in a more diverse distribution of structural stages, especially in lower elevations, and a more divided landscape of smaller forest stands. The NMS ordination emphasized the dissimilarity between the severe +6° scenarios and the other two temperature scenarios. The +0° and +3° scenarios differed from each other in composition (mainly because cool forest was lost in the +3° scenarios), but within a given level of fire suppression they remained remarkably similar in terms of overall composition, structure, and landscape pattern, while the +6° scenarios separated noticeably from them. Such decisive differences suggest that under the simulated ranges of precipitation and fire suppression, the interval between 3 and 6 degrees of warming on this landscape may capture an ecological threshold, or tipping point. Additional simulation research that incorporates (for example) management actions, insects and pathogens, and a wider array of precipitation scenarios could help illuminate more clearly the possible range of future landscape conditions. Still, these results provide a glimpse of potential divergent outcomes on this important landscape under possible future climates, and suggest that these forests will undergo considerable changes from both historical and current conditions in response to higher temperatures expected in this area. Some changes may be inevitable with warming, such as the upslope shift of warm forest types, but careful planning for fire and fuels management might allow land managers to modulate fire behavior and steer vegetation dynamics toward the most desirable outcome possible. Close

• 8. [Article] Does wildfire likelihood increase following insect outbreaks in conifer 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.esajournals.org/loi/ecsp

  Citation × Citation Citation Abstract Copy Title: Does wildfire likelihood increase following insect outbreaks in conifer forests? Author: Shaw, David C., Campbell, John L., Bailey, John D., Kennedy, Robert E., Zald, Harold S. J., Meigs, Garrett W. This is the publisher’s final pdf. The published article is copyrighted by Ecological Society of America and can be found at: http://www.esajournals.org/loi/ecsp Title: Does wildfire likelihood increase following insect outbreaks in conifer forests? Author: Shaw, David C., Campbell, John L., Bailey, John D., Kennedy, Robert E., Zald, Harold S. J., Meigs, Garrett W. This is the publisher’s final pdf. The published article is copyrighted by Ecological Society of America and can be found at: http://www.esajournals.org/loi/ecsp Close

• 9. [Article] Does wildfire likelihood increase following insect outbreaks in conifer forests?

  This is the publisher’s final pdf. The published article is copyrighted by The Author(s) and published by the Ecological Society of America. It can be found at: http://www.esajournals.org/loi/ecsp

  Citation × Citation Citation Abstract Copy Title: Does wildfire likelihood increase following insect outbreaks in conifer forests? Author: Meigs, Garrett W., Campbell, John L., Bailey, John D., Kennedy, Robert E., Zald, Harold S. J., Shaw, David C. This is the publisher’s final pdf. The published article is copyrighted by The Author(s) and published by the Ecological Society of America. It can be found at: http://www.esajournals.org/loi/ecsp Title: Does wildfire likelihood increase following insect outbreaks in conifer forests? Author: Meigs, Garrett W., Campbell, John L., Bailey, John D., Kennedy, Robert E., Zald, Harold S. J., Shaw, David C. This is the publisher’s final pdf. The published article is copyrighted by The Author(s) and published by the Ecological Society of America. It can be found at: http://www.esajournals.org/loi/ecsp Close

• 10. [Article] Does wildfire likelihood increase following insect outbreaks in conifer forests?

  This is the publisher’s final pdf. The published article is copyrighted by The Author(s) and published by the Ecological Society of America. It can be found at: http://www.esajournals.org/loi/ecsp

  Citation × Citation Citation Abstract Copy Title: Does wildfire likelihood increase following insect outbreaks in conifer forests? Author: Shaw, David C., Campbell, John L., Bailey, John D., Kennedy, Robert E., Zald, Harold S. J., Meigs, Garrett W. This is the publisher’s final pdf. The published article is copyrighted by The Author(s) and published by the Ecological Society of America. It can be found at: http://www.esajournals.org/loi/ecsp Title: Does wildfire likelihood increase following insect outbreaks in conifer forests? Author: Shaw, David C., Campbell, John L., Bailey, John D., Kennedy, Robert E., Zald, Harold S. J., Meigs, Garrett W. This is the publisher’s final pdf. The published article is copyrighted by The Author(s) and published by the Ecological Society of America. It can be found at: http://www.esajournals.org/loi/ecsp Close