Pub Date : 2024-05-13DOI: 10.1186/s42408-024-00276-w
David Beltrán-Marcos, Susana Suárez-Seoane, José Manuel Fernández-Guisuraga, João C. Azevedo, Leonor Calvo
Designing effective land management actions addressed to increase ecosystem resilience requires us to understand how shifting fire regimes are shaping landscapes. In this study, we aim to assess the link between fire regime and pre-fire vegetation biophysical characteristics (type, amount, and structure) in controlling extreme fire behavior across Atlantic-Transition-Mediterranean bioregions in Spain marked by different summer drought conditions and dominant plant regenerative traits. We used remote sensing metrics to estimate fire severity and pre-fire vegetation characteristics in eight study areas recently affected by large and highly severe wildfires under different environmental contexts. Furthermore, to account for fire regime attributes, we retrieved, for each target wildfire, the perimeter of the past wildfires that occurred between 1985 and 2022 and calculated fire recurrence, the time the since last fire (TSLF), and fire severity of previous wildfires (FSPW). The effect of fire regime attributes on pre-fire vegetation was examined using generalized linear mixed models (GLMMs). During the study period, fire recurrence decreased significantly in all bioregions analyzed. Fire severity increased under Atlantic conditions and decreased under Mediterranean environmental context, where the time since the last fire was the highest. Pre-fire fuel type and amount were identified as primary drivers of fire severity, being both strongly modulated by fire regime but following distinct mechanisms depending on the environmental context of each bioregion. In Atlantic sites, more frequent past wildfires of low to moderate fire severity were associated with a greater dominance of fire-prone shrublands with moderate fuel amounts, which increases the risk of severe wildfires. Similar trends occurred in Transition and Mediterranean sites but under the previous occurrence of highly severe wildfires. Specifically, long times after highly severe wildfires (> 30 years) increased fuel amount in conifer-dominated ecosystems in all bioregions analyzed, heightening susceptibility to extreme fire behavior. Our findings highlight that fire-prone ecosystems need adaptative management strategies to mitigate the effects of fire regime changes, but these actions should be specific to the climatic and ecological context.
{"title":"Fire regime attributes shape pre-fire vegetation characteristics controlling extreme fire behavior under different bioregions in Spain","authors":"David Beltrán-Marcos, Susana Suárez-Seoane, José Manuel Fernández-Guisuraga, João C. Azevedo, Leonor Calvo","doi":"10.1186/s42408-024-00276-w","DOIUrl":"https://doi.org/10.1186/s42408-024-00276-w","url":null,"abstract":"Designing effective land management actions addressed to increase ecosystem resilience requires us to understand how shifting fire regimes are shaping landscapes. In this study, we aim to assess the link between fire regime and pre-fire vegetation biophysical characteristics (type, amount, and structure) in controlling extreme fire behavior across Atlantic-Transition-Mediterranean bioregions in Spain marked by different summer drought conditions and dominant plant regenerative traits. We used remote sensing metrics to estimate fire severity and pre-fire vegetation characteristics in eight study areas recently affected by large and highly severe wildfires under different environmental contexts. Furthermore, to account for fire regime attributes, we retrieved, for each target wildfire, the perimeter of the past wildfires that occurred between 1985 and 2022 and calculated fire recurrence, the time the since last fire (TSLF), and fire severity of previous wildfires (FSPW). The effect of fire regime attributes on pre-fire vegetation was examined using generalized linear mixed models (GLMMs). During the study period, fire recurrence decreased significantly in all bioregions analyzed. Fire severity increased under Atlantic conditions and decreased under Mediterranean environmental context, where the time since the last fire was the highest. Pre-fire fuel type and amount were identified as primary drivers of fire severity, being both strongly modulated by fire regime but following distinct mechanisms depending on the environmental context of each bioregion. In Atlantic sites, more frequent past wildfires of low to moderate fire severity were associated with a greater dominance of fire-prone shrublands with moderate fuel amounts, which increases the risk of severe wildfires. Similar trends occurred in Transition and Mediterranean sites but under the previous occurrence of highly severe wildfires. Specifically, long times after highly severe wildfires (> 30 years) increased fuel amount in conifer-dominated ecosystems in all bioregions analyzed, heightening susceptibility to extreme fire behavior. Our findings highlight that fire-prone ecosystems need adaptative management strategies to mitigate the effects of fire regime changes, but these actions should be specific to the climatic and ecological context.","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"32 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-13DOI: 10.1186/s42408-024-00277-9
Kate M. Wilkin, Amanda M. Stasiewicz, Susan D. Kocher
Globally, prescribed fire political interest and practice has been rekindled following recent devastating wildfire seasons. This phenomenon was especially acute in areas with dual wildfire and forest health crises, like California. Previous research has investigated prescribed fire on public lands or on private lands in other regions, but little is known about prescribed fire practice or interest on private lands in California. Therefore, we sought to understand private land managers’ perceptions of prescribed fire compared to other land management techniques, treatment pathways, motivations, and barriers to complete these treatments in California. Before workshops on prescribed fire for private lands, we surveyed participants in six prescribed fires on private lands workshops in the Central Sierra Nevada from 2018 to 2019 (N = 172). We found that participants “want to use” pile burns and broadcast prescribed fires more than other land management treatments. There was also a strong interest in mechanical treatments in contrast to low interest in grazing. Some participants had “heard about” and “want to use” some pathways to apply prescribed fire on their lands, including government programs, contractors, friends and family, and Prescribed Burn Associations (PBAs). People had multiple objectives for their prescribed fire goals, and the majority wanted to promote ecosystem health, e.g., reduce fire hazards, foster natural land health, and reduce invasive plants. Perceived barriers were greatest for safety, cost, and resources while fewer participants perceived permits as a barrier. Participants were in the early stages of considering using broadcast prescribed fire and would like to burn small areas, potentially to build confidence and skills. At the time of our research, there was strong interest in using prescribed fire on private lands, and some perceived best pathways and barriers to be unique from prescribed fire practice on public lands. At the same time, private lands managers who responded said they want to promote ecosystem health and reduce wildfire risk and impacts, which is a shared a common motivation with public lands managers. Studies and reports on prescribed burning need to clearly distinguish between broadcast prescribed burning and pile burning to ensure consistency in results and conclusions about prescribed fire use.
{"title":"Private landowner interest in prescribed fire in California: findings from workshops in the Sierra Nevada","authors":"Kate M. Wilkin, Amanda M. Stasiewicz, Susan D. Kocher","doi":"10.1186/s42408-024-00277-9","DOIUrl":"https://doi.org/10.1186/s42408-024-00277-9","url":null,"abstract":"Globally, prescribed fire political interest and practice has been rekindled following recent devastating wildfire seasons. This phenomenon was especially acute in areas with dual wildfire and forest health crises, like California. Previous research has investigated prescribed fire on public lands or on private lands in other regions, but little is known about prescribed fire practice or interest on private lands in California. Therefore, we sought to understand private land managers’ perceptions of prescribed fire compared to other land management techniques, treatment pathways, motivations, and barriers to complete these treatments in California. Before workshops on prescribed fire for private lands, we surveyed participants in six prescribed fires on private lands workshops in the Central Sierra Nevada from 2018 to 2019 (N = 172). We found that participants “want to use” pile burns and broadcast prescribed fires more than other land management treatments. There was also a strong interest in mechanical treatments in contrast to low interest in grazing. Some participants had “heard about” and “want to use” some pathways to apply prescribed fire on their lands, including government programs, contractors, friends and family, and Prescribed Burn Associations (PBAs). People had multiple objectives for their prescribed fire goals, and the majority wanted to promote ecosystem health, e.g., reduce fire hazards, foster natural land health, and reduce invasive plants. Perceived barriers were greatest for safety, cost, and resources while fewer participants perceived permits as a barrier. Participants were in the early stages of considering using broadcast prescribed fire and would like to burn small areas, potentially to build confidence and skills. At the time of our research, there was strong interest in using prescribed fire on private lands, and some perceived best pathways and barriers to be unique from prescribed fire practice on public lands. At the same time, private lands managers who responded said they want to promote ecosystem health and reduce wildfire risk and impacts, which is a shared a common motivation with public lands managers. Studies and reports on prescribed burning need to clearly distinguish between broadcast prescribed burning and pile burning to ensure consistency in results and conclusions about prescribed fire use.","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"37 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-08DOI: 10.1186/s42408-024-00273-z
Katherine E. Golden, Benjamin L. Hemingway, Amy E. Frazier, Wade Harrell, Samuel D. Fuhlendorf, Craig A. Davis
The southeastern United States consists of diverse ecosystems, many of which are fire-dependent. Fires were common during pre-European times, and many were anthropogenic in origin. Understanding how prescribed burning practices in use today compare to historic fire regimes can provide perspective and context on the role of fire in critical ecosystems. On the Aransas National Wildlife Refuge (ANWR), prescribed burning is conducted to prevent live oak (Quercus fusiformis) encroachment and preserve the openness of the herbaceous wetlands and grasslands for endangered whooping cranes (Grus americana) and Aplomado falcons (Falco femoralis). This field note builds a digital fire atlas of recent prescribed burning on the refuge and compares it to the historical fire ecology of ANWR. Findings indicate that the refuge is maintaining fire-dependent ecosystems with an extensive burn program that includes a fire return interval between 2 and 10 years on a majority of the refuge, with some locations experiencing much longer intervals. These fire return intervals are much shorter than the historic burn regime according to LANDFIRE. Following the fire return intervals projected by LANDFIRE, which project longer intervals than the prescribed fire program, would likely be detrimental to endangered species management by allowing increased woody plant encroachment and loss of open habitat important to whooping cranes and Aplomado falcons. Since prescribed fire is part of the management objectives on many national wildlife refuges in the United States, quantifying recent and historical fire ecology can provide useful insights into future management efforts, particularly in cases where endangered species are of special concern and management efforts may be counter to historical disturbance regimes.
{"title":"Historical and recent fire ecology on national wildlife refuges: a case study on Aransas National Wildlife Refuge","authors":"Katherine E. Golden, Benjamin L. Hemingway, Amy E. Frazier, Wade Harrell, Samuel D. Fuhlendorf, Craig A. Davis","doi":"10.1186/s42408-024-00273-z","DOIUrl":"https://doi.org/10.1186/s42408-024-00273-z","url":null,"abstract":"The southeastern United States consists of diverse ecosystems, many of which are fire-dependent. Fires were common during pre-European times, and many were anthropogenic in origin. Understanding how prescribed burning practices in use today compare to historic fire regimes can provide perspective and context on the role of fire in critical ecosystems. On the Aransas National Wildlife Refuge (ANWR), prescribed burning is conducted to prevent live oak (Quercus fusiformis) encroachment and preserve the openness of the herbaceous wetlands and grasslands for endangered whooping cranes (Grus americana) and Aplomado falcons (Falco femoralis). This field note builds a digital fire atlas of recent prescribed burning on the refuge and compares it to the historical fire ecology of ANWR. Findings indicate that the refuge is maintaining fire-dependent ecosystems with an extensive burn program that includes a fire return interval between 2 and 10 years on a majority of the refuge, with some locations experiencing much longer intervals. These fire return intervals are much shorter than the historic burn regime according to LANDFIRE. Following the fire return intervals projected by LANDFIRE, which project longer intervals than the prescribed fire program, would likely be detrimental to endangered species management by allowing increased woody plant encroachment and loss of open habitat important to whooping cranes and Aplomado falcons. Since prescribed fire is part of the management objectives on many national wildlife refuges in the United States, quantifying recent and historical fire ecology can provide useful insights into future management efforts, particularly in cases where endangered species are of special concern and management efforts may be counter to historical disturbance regimes.","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"6 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.1186/s42408-024-00279-7
C. Wade Ross, E. Louise Loudermilk, Joseph J. O’Brien, Steven A. Flanagan, Jennifer McDaniel, Doug P. Aubrey, Tripp Lowe, J. Kevin Hiers, Nicholas S. Skowronski
Longleaf pine (Pinus palustris) ecosystems are recognized as biodiversity hotspots, and their sustainability is tightly coupled to a complex nexus of feedbacks between fire, composition, and structure. While previous research has demonstrated that frequent fire is often associated with higher levels of biodiversity, relationships between fire frequency and forest structure are more nuanced because structure can be difficult to measure and characterize. We expanded on this body of research by using lidar to characterize vegetation structure in response to fire frequency at a long-term prescribed-fire experiment. We asked (1) how does prescribed fire frequency affect structure and (2) how do structural metrics vary in the strength of their relationships with fire frequency. Our results indicated that forest structure varied significantly in response to fire frequency, with more frequent fire reducing vegetation structural complexity. Metrics that characterized the central tendency of vegetation and/or the variance of canopy-related properties were weakly to moderately correlated with prescribed fire frequency, while metrics that captured the vertical dispersion or variability of vegetation throughout the forest strata were moderately to strongly correlated with fire frequency. Of all the metrics evaluated, the understory complexity index had the strongest correlation with fire frequency and explained 88% of the structural variation in response to prescribed fire treatments. The findings presented in this study highlight the usefulness of lidar technology for characterizing forest structure and that structural complexity cannot be fully characterized by a single metric. Instead, a range of diverse metrics is required to refine scientific understanding of the feedbacks between fire, composition, and structure in support of longleaf pine sustainability. Furthermore, there is a need for further research to broaden structural assessments beyond the overstory and incorporate more understory components, particularly within the realm of prescribed fire science and land management.
{"title":"Lidar-derived estimates of forest structure in response to fire frequency","authors":"C. Wade Ross, E. Louise Loudermilk, Joseph J. O’Brien, Steven A. Flanagan, Jennifer McDaniel, Doug P. Aubrey, Tripp Lowe, J. Kevin Hiers, Nicholas S. Skowronski","doi":"10.1186/s42408-024-00279-7","DOIUrl":"https://doi.org/10.1186/s42408-024-00279-7","url":null,"abstract":"Longleaf pine (Pinus palustris) ecosystems are recognized as biodiversity hotspots, and their sustainability is tightly coupled to a complex nexus of feedbacks between fire, composition, and structure. While previous research has demonstrated that frequent fire is often associated with higher levels of biodiversity, relationships between fire frequency and forest structure are more nuanced because structure can be difficult to measure and characterize. We expanded on this body of research by using lidar to characterize vegetation structure in response to fire frequency at a long-term prescribed-fire experiment. We asked (1) how does prescribed fire frequency affect structure and (2) how do structural metrics vary in the strength of their relationships with fire frequency. Our results indicated that forest structure varied significantly in response to fire frequency, with more frequent fire reducing vegetation structural complexity. Metrics that characterized the central tendency of vegetation and/or the variance of canopy-related properties were weakly to moderately correlated with prescribed fire frequency, while metrics that captured the vertical dispersion or variability of vegetation throughout the forest strata were moderately to strongly correlated with fire frequency. Of all the metrics evaluated, the understory complexity index had the strongest correlation with fire frequency and explained 88% of the structural variation in response to prescribed fire treatments. The findings presented in this study highlight the usefulness of lidar technology for characterizing forest structure and that structural complexity cannot be fully characterized by a single metric. Instead, a range of diverse metrics is required to refine scientific understanding of the feedbacks between fire, composition, and structure in support of longleaf pine sustainability. Furthermore, there is a need for further research to broaden structural assessments beyond the overstory and incorporate more understory components, particularly within the realm of prescribed fire science and land management.","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"1 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140888896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.1186/s42408-024-00278-8
Catrin M. Edgeley, William H. Cannon, Scott Pearse, Branko Kosović, Gabriele Pfister, Rajesh Kumar
Increased use of visualizations as wildfire communication tools with public and professional audiences—particularly 3D videos and virtual or augmented reality—invites discussion of their ethical use in varied social and temporal contexts. Existing studies focus on the use of such visualizations prior to fire events and commonly use hypothetical scenarios intended to motivate proactive mitigation or explore decision-making, overlooking the insights that those who have already experienced fire events can provide to improve user engagement and understanding of wildfire visualizations more broadly. We conducted semi-structured interviews with 101 residents and professionals affected by Colorado’s 2020 East Troublesome and 2021 Marshall Fires, using 3D model visualizations of fire events on tablets as a discussion tool to understand how fire behavior influenced evacuation experiences and decision-making. We provide empirically gathered insights that can inform the ethical use of wildfire visualizations by scientists, managers, and communicators working at the intersection of fire management and public safety. Study design, interview discussions, and field observations from both case studies reveal the importance of nuanced and responsive approaches for the use of 3D visualizations, with an emphasis on the implementation of protocols that ensure the risk of harm to the intended audience is minimal. We share five considerations for use of visualizations as communication tools with public and professional audiences, expanding existing research into post-fire spaces: (1) determine whether the use of visualizations will truly benefit users; (2) connect users to visualizations by incorporating local values; (3) provide context around model uncertainty; (4) design and share visualizations in ways that meet the needs of the user; (5) be cognizant of the emotional impacts that sharing wildfire visualizations can have. This research demonstrates the importance of study design and planning that considers the emotional and psychological well-being of users. For users that do wish to engage with visualizations, this technical note provides guidance for ensuring meaningful understandings that can generate new discussion and knowledge. We advocate for communication with visualizations that consider local context and provide opportunities for users to engage to a level that suits them, suggesting that visualizations should serve as catalysts for meaningful dialogue rather than conclusive information sources.
{"title":"Five social and ethical considerations for using wildfire visualizations as a communication tool","authors":"Catrin M. Edgeley, William H. Cannon, Scott Pearse, Branko Kosović, Gabriele Pfister, Rajesh Kumar","doi":"10.1186/s42408-024-00278-8","DOIUrl":"https://doi.org/10.1186/s42408-024-00278-8","url":null,"abstract":"Increased use of visualizations as wildfire communication tools with public and professional audiences—particularly 3D videos and virtual or augmented reality—invites discussion of their ethical use in varied social and temporal contexts. Existing studies focus on the use of such visualizations prior to fire events and commonly use hypothetical scenarios intended to motivate proactive mitigation or explore decision-making, overlooking the insights that those who have already experienced fire events can provide to improve user engagement and understanding of wildfire visualizations more broadly. We conducted semi-structured interviews with 101 residents and professionals affected by Colorado’s 2020 East Troublesome and 2021 Marshall Fires, using 3D model visualizations of fire events on tablets as a discussion tool to understand how fire behavior influenced evacuation experiences and decision-making. We provide empirically gathered insights that can inform the ethical use of wildfire visualizations by scientists, managers, and communicators working at the intersection of fire management and public safety. Study design, interview discussions, and field observations from both case studies reveal the importance of nuanced and responsive approaches for the use of 3D visualizations, with an emphasis on the implementation of protocols that ensure the risk of harm to the intended audience is minimal. We share five considerations for use of visualizations as communication tools with public and professional audiences, expanding existing research into post-fire spaces: (1) determine whether the use of visualizations will truly benefit users; (2) connect users to visualizations by incorporating local values; (3) provide context around model uncertainty; (4) design and share visualizations in ways that meet the needs of the user; (5) be cognizant of the emotional impacts that sharing wildfire visualizations can have. This research demonstrates the importance of study design and planning that considers the emotional and psychological well-being of users. For users that do wish to engage with visualizations, this technical note provides guidance for ensuring meaningful understandings that can generate new discussion and knowledge. We advocate for communication with visualizations that consider local context and provide opportunities for users to engage to a level that suits them, suggesting that visualizations should serve as catalysts for meaningful dialogue rather than conclusive information sources.","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"19 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140888900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-06DOI: 10.1186/s42408-024-00275-x
Karma Tenzin, Craig R. Nitschke, Kathryn J. Allen, Paul J. Krusic, Edward R. Cook, Thiet V. Nguyen, Patrick J. Baker
Chir pine (Pinus roxburghii Sarg.) forests are distributed in the dry valleys of Bhutan Himalaya. In the past, these forests have been heavily influenced by human activities such as grazing, burning, resin tapping, and collection of non-timber forest products. Bhutan’s Forest Act of 1969, which shifted forest management from local community control to centralized governmental control, greatly restricted these activities. To understand the implications of the Forest Act on the chir pine forests, we used tree-rings and fire scars to reconstruct the fire history of a chir pine forest in eastern Bhutan. This provided an opportunity to characterize the fire regime before and after the Forest Act of 1969 was implemented and assess the scale and magnitude of changes that have occurred. We developed a 120-year chir pine fire chronology from nine sites within a single forested landscape. Between 1900 and ~ 1970, fires were small and patchy. When fires occurred, they were limited to one to two sites within the larger study area. After 1970, there was a distinct shift in fire activity, with fires in 1985, 1989, 1996, 2000, and 2013 burning > 90% of sample plots. Fire activity was positively associated with La Niña conditions (wetter, cooler) in the preceding year. This is likely the result of increased accumulation and connectivity of fuels on the forest floor in wetter years. Prior to 1970, the fire regime in the studied chir pine landscape in eastern Bhutan was dominated by patchy, low-intensity fires indicating that the fire regime was fuel limited. After 1970, fires became larger and more frequent. This shift was associated with the enactment of the Bhutan Forest Act in 1969, which regulated grazing and implemented a policy of strict fire exclusion in government-reserved forests. This likely led to a large buildup of fuels, particularly after La Niña years. Historical patterns of grazing and low-intensity fires prior to the Forest Act kept fuel loads low and disconnected. The cessation of most human activities in these forests after 1969 resulted in an increase in fuel loads and connectivity within the landscape. This has greatly reshaped fire regimes in the chir pine forests of eastern Bhutan over the past half century.
{"title":"Climate and humans interact to shape the fire regime of a chir pine (Pinus roxburghii) forest in eastern Bhutan","authors":"Karma Tenzin, Craig R. Nitschke, Kathryn J. Allen, Paul J. Krusic, Edward R. Cook, Thiet V. Nguyen, Patrick J. Baker","doi":"10.1186/s42408-024-00275-x","DOIUrl":"https://doi.org/10.1186/s42408-024-00275-x","url":null,"abstract":"Chir pine (Pinus roxburghii Sarg.) forests are distributed in the dry valleys of Bhutan Himalaya. In the past, these forests have been heavily influenced by human activities such as grazing, burning, resin tapping, and collection of non-timber forest products. Bhutan’s Forest Act of 1969, which shifted forest management from local community control to centralized governmental control, greatly restricted these activities. To understand the implications of the Forest Act on the chir pine forests, we used tree-rings and fire scars to reconstruct the fire history of a chir pine forest in eastern Bhutan. This provided an opportunity to characterize the fire regime before and after the Forest Act of 1969 was implemented and assess the scale and magnitude of changes that have occurred. We developed a 120-year chir pine fire chronology from nine sites within a single forested landscape. Between 1900 and ~ 1970, fires were small and patchy. When fires occurred, they were limited to one to two sites within the larger study area. After 1970, there was a distinct shift in fire activity, with fires in 1985, 1989, 1996, 2000, and 2013 burning > 90% of sample plots. Fire activity was positively associated with La Niña conditions (wetter, cooler) in the preceding year. This is likely the result of increased accumulation and connectivity of fuels on the forest floor in wetter years. Prior to 1970, the fire regime in the studied chir pine landscape in eastern Bhutan was dominated by patchy, low-intensity fires indicating that the fire regime was fuel limited. After 1970, fires became larger and more frequent. This shift was associated with the enactment of the Bhutan Forest Act in 1969, which regulated grazing and implemented a policy of strict fire exclusion in government-reserved forests. This likely led to a large buildup of fuels, particularly after La Niña years. Historical patterns of grazing and low-intensity fires prior to the Forest Act kept fuel loads low and disconnected. The cessation of most human activities in these forests after 1969 resulted in an increase in fuel loads and connectivity within the landscape. This has greatly reshaped fire regimes in the chir pine forests of eastern Bhutan over the past half century. ","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"31 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140888894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-03DOI: 10.1186/s42408-024-00274-y
Benjamin Wagner, Patrick J. Baker, Craig R. Nitschke
Tree hollows are an important habitat resource used by arboreal fauna for nesting and denning. Hollows form when trees mature and are exposed to decay and physical damage. In the absence of excavating fauna, hollow formation can take up to 200 years in Australian temperate Eucalyptus forests, making tree hollows a critical but slow forming habitat feature. The increasing frequency and severity of wildfires due to climate change has led to increased concern about the landscape-scale loss of nesting space for arboreal fauna, including endangered species such as the folivorous southern greater glider (Petauroides volans). To understand patterns of nesting resource availability, we assessed drivers of hollow occurrence in southeastern Australian mixed-species Eucalyptus forests and quantified the effects of an unprecedented large-scale wildfire, the 2019/2020 Black Summer bushfires, on hollow occurrence and abundance. Tree size and shape, as well as site productivity and topography, were important predictors for hollow occurrence both before and after the fires. The occurrence of the southern greater glider was strongly dependent on high proportions of hollow-bearing trees. While high fire severities had a negative impact on southern greater glider occurrence, the number of hollow-dependent arboreal species was not affected. While the wildfires significantly reduced hollow abundance, we did not find significant effects on hollow occurrence. Fires altered the relationship between tree size and hollow occurrence expressed as a change in the probability of hollow occurrence, with a higher likelihood at smaller tree sizes after the fires. Our findings suggest that post-fire nesting space may be reduced at the tree-scale, while at the stand-scale, hollow-bearing trees persist as biological legacies. These persisting trees can support the recovery of hollow-dependent arboreal fauna, such as the endangered southern greater glider by providing denning and nesting space. Hollow-bearing trees that survived the fires have the potential to form new hollows faster compared to undisturbed mature trees.
{"title":"How an unprecedented wildfire shaped tree hollow occurrence and abundance—implications for arboreal fauna","authors":"Benjamin Wagner, Patrick J. Baker, Craig R. Nitschke","doi":"10.1186/s42408-024-00274-y","DOIUrl":"https://doi.org/10.1186/s42408-024-00274-y","url":null,"abstract":"Tree hollows are an important habitat resource used by arboreal fauna for nesting and denning. Hollows form when trees mature and are exposed to decay and physical damage. In the absence of excavating fauna, hollow formation can take up to 200 years in Australian temperate Eucalyptus forests, making tree hollows a critical but slow forming habitat feature. The increasing frequency and severity of wildfires due to climate change has led to increased concern about the landscape-scale loss of nesting space for arboreal fauna, including endangered species such as the folivorous southern greater glider (Petauroides volans). To understand patterns of nesting resource availability, we assessed drivers of hollow occurrence in southeastern Australian mixed-species Eucalyptus forests and quantified the effects of an unprecedented large-scale wildfire, the 2019/2020 Black Summer bushfires, on hollow occurrence and abundance. Tree size and shape, as well as site productivity and topography, were important predictors for hollow occurrence both before and after the fires. The occurrence of the southern greater glider was strongly dependent on high proportions of hollow-bearing trees. While high fire severities had a negative impact on southern greater glider occurrence, the number of hollow-dependent arboreal species was not affected. While the wildfires significantly reduced hollow abundance, we did not find significant effects on hollow occurrence. Fires altered the relationship between tree size and hollow occurrence expressed as a change in the probability of hollow occurrence, with a higher likelihood at smaller tree sizes after the fires. Our findings suggest that post-fire nesting space may be reduced at the tree-scale, while at the stand-scale, hollow-bearing trees persist as biological legacies. These persisting trees can support the recovery of hollow-dependent arboreal fauna, such as the endangered southern greater glider by providing denning and nesting space. Hollow-bearing trees that survived the fires have the potential to form new hollows faster compared to undisturbed mature trees.","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"54 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140832349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1186/s42408-024-00271-1
Gavin M. Jones, Marion A. Clément, Christopher E. Latimer, Marilyn E. Wright, Jamie S. Sanderlin, Shaula J. Hedwall, Rebecca Kirby
Changing fire regimes have the potential to threaten wildlife populations and communities. Understanding species’ responses to novel fire regimes is critical to formulating effective management and conservation strategies in an era of rapid change. Here, we examined the empirical effects of recent and historical wildfire activity on Mexican spotted owl (Strix occidentalis lucida) populations in the southwestern United States. Using region-wide, standardized detection/non-detection data of Mexican spotted owl breeding pairs collected from 2015 to 2022, we found (i) higher rates of pair occupancy at sites that experienced more frequent fires in the three decades prior to the initiation of our study, and (ii) lower rates of local persistence at sites that experienced more extensive high-severity fire during the study. Historical fire regimes throughout much of our study area were characterized by high fire frequencies and limited high-severity components, indicating that Mexican spotted owls responded to wildfire in a manner consistent with their evolutionary environment. Management activities such as prescribed burning and mechanical thinning that aim to reduce stand-replacing fire risk and re-introduce the potential for frequent-fire regimes will likely benefit Mexican spotted owl conservation objectives, as well as promote more resilient forest landscapes.
不断变化的火灾机制有可能威胁野生动物种群和群落。在快速变化的时代,了解物种对新的火灾机制的反应对于制定有效的管理和保护策略至关重要。在这里,我们研究了最近和历史上的野火活动对美国西南部墨西哥斑头鸺鹠(Strix occidentalis lucida)种群的实证影响。利用从2015年到2022年收集的全地区墨西哥斑鸮繁殖对的标准化检测/未检测数据,我们发现:(i)在研究开始前的三十年间,火灾发生频率较高的地点,繁殖对的占有率较高;(ii)在研究期间,火灾发生频率较高的地点,繁殖对的持续率较低。在我们研究区域的大部分地区,历史火灾机制的特点是火灾频率较高,而严重程度较高的成分有限,这表明墨西哥斑鸮对野火的反应方式与其进化环境相一致。规定燃烧和机械疏伐等旨在降低林分替代火灾风险并重新引入频繁火灾机制的管理活动可能会有利于墨西哥斑鸮的保护目标,并促进森林景观更具复原力。
{"title":"Frequent burning and limited stand-replacing fire supports Mexican spotted owl pair occupancy","authors":"Gavin M. Jones, Marion A. Clément, Christopher E. Latimer, Marilyn E. Wright, Jamie S. Sanderlin, Shaula J. Hedwall, Rebecca Kirby","doi":"10.1186/s42408-024-00271-1","DOIUrl":"https://doi.org/10.1186/s42408-024-00271-1","url":null,"abstract":"Changing fire regimes have the potential to threaten wildlife populations and communities. Understanding species’ responses to novel fire regimes is critical to formulating effective management and conservation strategies in an era of rapid change. Here, we examined the empirical effects of recent and historical wildfire activity on Mexican spotted owl (Strix occidentalis lucida) populations in the southwestern United States. Using region-wide, standardized detection/non-detection data of Mexican spotted owl breeding pairs collected from 2015 to 2022, we found (i) higher rates of pair occupancy at sites that experienced more frequent fires in the three decades prior to the initiation of our study, and (ii) lower rates of local persistence at sites that experienced more extensive high-severity fire during the study. Historical fire regimes throughout much of our study area were characterized by high fire frequencies and limited high-severity components, indicating that Mexican spotted owls responded to wildfire in a manner consistent with their evolutionary environment. Management activities such as prescribed burning and mechanical thinning that aim to reduce stand-replacing fire risk and re-introduce the potential for frequent-fire regimes will likely benefit Mexican spotted owl conservation objectives, as well as promote more resilient forest landscapes.","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"6 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140634996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study deals with wildfires in marginal areas of the Mediterranean climatic and biogeographical regions (Northern Mediterranean) where fires were not common. The aim of the research was to determine the differences in floristic composition and traits at different intensities of fire damage and to analyze the changes in forest ecosystems during the wildfires that took place in the summer of 2022. The study included both the zonal forests and non-native black pine (Pinus nigra) forests. Remote sensing techniques linked to the vegetation data sampled in the field during the 2023 vegetation season, the very first season after the fires, were also used in the fire assessment. The study confirmed that satellite data analysis, orthophoto interpretation, and on-site vegetation sampling provide equivalent information on fire severity, opening up the possibility of transferring knowledge to similar post-fire sites without field sampling in the future. TWINSPAN classification analysis divided the sampled plots into clusters based on tree species prevalence and fire severity. The diagnostic species of the clusters were calculated using a fidelity measure. Ordination revealed that the first axis on the detrended correspondence analysis (DCA) correlated with wildfire severity. Ecological conditions and strategies, life forms, chorotypes, seed dispersal classes, and regeneration traits were analyzed along this gradient. We found that post-fire sites became warmer, drier, and lighter, which favored the growth of ruderal, theropytic, cosmopolitan, anemochorous and post-fire emergent species. After the fire, a “wave” of annual ruderal species was observed. The results indicate that post-fire recovery can be left to natural processes without human intervention, except in the case of non-native pine stands where planting or seeding may be necessary. Otherwise, it is essential to control the possible occurrence of invasive species. Isolated adaptations of species to fire have also been observed, such as heat-stimulated germination. Such adaptations could develop in regions exposed to frequent fires and where fires act as an evolutionary factor.
{"title":"Response of vulnerable karst forest ecosystems under different fire severities in the Northern Dinaric Karst mountains (Slovenia)","authors":"Lucia Čahojová, Aljaž Jakob, Mateja Breg Valjavec, Andraž Čarni","doi":"10.1186/s42408-024-00267-x","DOIUrl":"https://doi.org/10.1186/s42408-024-00267-x","url":null,"abstract":"This study deals with wildfires in marginal areas of the Mediterranean climatic and biogeographical regions (Northern Mediterranean) where fires were not common. The aim of the research was to determine the differences in floristic composition and traits at different intensities of fire damage and to analyze the changes in forest ecosystems during the wildfires that took place in the summer of 2022. The study included both the zonal forests and non-native black pine (Pinus nigra) forests. Remote sensing techniques linked to the vegetation data sampled in the field during the 2023 vegetation season, the very first season after the fires, were also used in the fire assessment. The study confirmed that satellite data analysis, orthophoto interpretation, and on-site vegetation sampling provide equivalent information on fire severity, opening up the possibility of transferring knowledge to similar post-fire sites without field sampling in the future. TWINSPAN classification analysis divided the sampled plots into clusters based on tree species prevalence and fire severity. The diagnostic species of the clusters were calculated using a fidelity measure. Ordination revealed that the first axis on the detrended correspondence analysis (DCA) correlated with wildfire severity. Ecological conditions and strategies, life forms, chorotypes, seed dispersal classes, and regeneration traits were analyzed along this gradient. We found that post-fire sites became warmer, drier, and lighter, which favored the growth of ruderal, theropytic, cosmopolitan, anemochorous and post-fire emergent species. After the fire, a “wave” of annual ruderal species was observed. The results indicate that post-fire recovery can be left to natural processes without human intervention, except in the case of non-native pine stands where planting or seeding may be necessary. Otherwise, it is essential to control the possible occurrence of invasive species. Isolated adaptations of species to fire have also been observed, such as heat-stimulated germination. Such adaptations could develop in regions exposed to frequent fires and where fires act as an evolutionary factor.","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"98 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140613332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-04DOI: 10.1186/s42408-024-00263-1
John Craycroft, Callie Schweitzer
For at least four decades, practitioners have recognized advantages of aerial versus ground ignition for maximizing the effectiveness of prescribed fires. For example, larger areas can be ignited in less time, or ignition energy may be variously targeted over an area in accordance with the uneven distribution of fuels. The maturation of wireless communication, geopositioning systems, and unmanned aerial systems (UAS) has enhanced those advantages, and UAS approaches also provide further advantages relative to helicopter ignitions, such as reduced risk to human safety, lower operating costs, and higher operational flexibility. In a long running study at the Bankhead National Forest in northcentral Alabama, prescribed fire has been used for nearly 20 years. Most of the burns have been hand-ignited via drip torches, while some have been aerially ignited via helicopter. In March 2022, for the first time, a UAS was used to ignite prescribed fires across a landscape that included a long-term research stand. This field note relates comparisons of both fire behavior and fuel consumption metrics for the UAS-ignited burn versus previous burns on the same stand, and versus burns of other research stands in the same year. The UAS-ignited prescribed fire experienced burn effects similar to those from ground-ignited prescribed fires on the same stand in previous years, as well as those from ground-ignited prescribed fires on other stands in the same year. This post hoc analysis suggests that UAS ignition approaches may be sufficient for achieving prescribed burn goals, thereby enabling practitioners to realize the advantages offered by that ignition mode.
{"title":"Case study of UAS ignition of prescribed fire in a mixedwood on the William B. Bankhead National Forest, Alabama","authors":"John Craycroft, Callie Schweitzer","doi":"10.1186/s42408-024-00263-1","DOIUrl":"https://doi.org/10.1186/s42408-024-00263-1","url":null,"abstract":"For at least four decades, practitioners have recognized advantages of aerial versus ground ignition for maximizing the effectiveness of prescribed fires. For example, larger areas can be ignited in less time, or ignition energy may be variously targeted over an area in accordance with the uneven distribution of fuels. The maturation of wireless communication, geopositioning systems, and unmanned aerial systems (UAS) has enhanced those advantages, and UAS approaches also provide further advantages relative to helicopter ignitions, such as reduced risk to human safety, lower operating costs, and higher operational flexibility. In a long running study at the Bankhead National Forest in northcentral Alabama, prescribed fire has been used for nearly 20 years. Most of the burns have been hand-ignited via drip torches, while some have been aerially ignited via helicopter. In March 2022, for the first time, a UAS was used to ignite prescribed fires across a landscape that included a long-term research stand. This field note relates comparisons of both fire behavior and fuel consumption metrics for the UAS-ignited burn versus previous burns on the same stand, and versus burns of other research stands in the same year. The UAS-ignited prescribed fire experienced burn effects similar to those from ground-ignited prescribed fires on the same stand in previous years, as well as those from ground-ignited prescribed fires on other stands in the same year. This post hoc analysis suggests that UAS ignition approaches may be sufficient for achieving prescribed burn goals, thereby enabling practitioners to realize the advantages offered by that ignition mode.","PeriodicalId":12273,"journal":{"name":"Fire Ecology","volume":"120 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140572065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}