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Crowley MA, Stockdale CA, Johnston JM, Wulder MA, Liu T, McCarty JL, Rieb JT, Cardille JA, White JC. Towards a whole-system framework for wildfire monitoring using Earth observations. GLOBAL CHANGE BIOLOGY 2023; 29:1423-1436. [PMID: 36537002 DOI: 10.1111/gcb.16567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 12/09/2022] [Accepted: 12/09/2022] [Indexed: 05/26/2023]
Abstract
Fire seasons have become increasingly variable and extreme due to changing climatological, ecological, and social conditions. Earth observation data are critical for monitoring fires and their impacts. Herein, we present a whole-system framework for identifying and synthesizing fire monitoring objectives and data needs throughout the life cycle of a fire event. The four stages of fire monitoring using Earth observation data include the following: (1) pre-fire vegetation inventories, (2) active-fire monitoring, (3) post-fire assessment, and (4) multi-scale synthesis. We identify the challenges and opportunities associated with current approaches to fire monitoring, highlighting four case studies from North American boreal, montane, and grassland ecosystems. While the case studies are localized to these ecosystems and regional contexts, they provide insights for others experiencing similar monitoring challenges worldwide. The field of remote sensing is experiencing a rapid proliferation of new data sources, providing observations that can inform all aspects of our fire monitoring framework; however, significant challenges for meeting fire monitoring objectives remain. We identify future opportunities for data sharing and rapid co-development of information products using cloud computing that benefits from open-access Earth observation and other geospatial data layers.
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Affiliation(s)
- Morgan A Crowley
- Canadian Forest Service (Great Lakes Forestry Centre), Natural Resources Canada, Sault Sainte Marie, Ontario, Canada
| | - Christopher A Stockdale
- Canadian Forest Service (Northern Forestry Centre), Natural Resources Canada, Edmonton, Alberta, Canada
| | - Joshua M Johnston
- Canadian Forest Service (Great Lakes Forestry Centre), Natural Resources Canada, Sault Sainte Marie, Ontario, Canada
| | - Michael A Wulder
- Canadian Forest Service (Pacific Forestry Centre), Natural Resources Canada, Victoria, British Columbia, Canada
| | - Tianjia Liu
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts, USA
| | - Jessica L McCarty
- Department of Geography and Geospatial Analysis Center, Miami University, Oxford, Ohio, USA
| | - Jesse T Rieb
- Department of Geography, McGill University, Montréal, Québec, Canada
| | - Jeffrey A Cardille
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Québec, Canada
| | - Joanne C White
- Canadian Forest Service (Pacific Forestry Centre), Natural Resources Canada, Victoria, British Columbia, Canada
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2
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Lindenmayer DB, Bowd EJ, Gibbons P. Forest restoration in a time of fire: perspectives from tall, wet eucalypt forests subject to stand-replacing wildfires. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210082. [PMID: 36373929 PMCID: PMC9661950 DOI: 10.1098/rstb.2021.0082] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 09/30/2021] [Indexed: 11/16/2022] Open
Abstract
Wildfires have the potential to add considerably to the already significant challenge of achieving effective forest restoration in the UN Decade on Ecosystem Restoration. While fire can sometimes promote forest restoration (e.g. by creating otherwise rare, early successional habitats), it can thwart it in others (e.g. by depleting key patch types and stand structures). Here we outline key considerations in facilitating restoration of some tall wet temperate forest ecosystems and some boreal forest ecosystems where the typical fire regime is rare high-severity stand-replacing fire. Some of these ecosystems are experiencing altered fire regimes such as increased fire extent, severity and/or frequency. Achieving good restoration outcomes in such ecosystems demands understanding fire regimes and their impacts on vegetation and other elements of biodiversity and then selecting ecosystem-appropriate management interventions. Potential actions range from doing nothing (as the ecosystem already maintains full post-fire regenerative capacity) to interventions prior to a conflagration like prescribed burning to limit the risks of high-severity fire, excluding activities that impair post-fire recovery (e.g. post-fire logging), and artificial seeding where natural regeneration fails. The most ecologically effective actions will be ecosystem-specific and context-specific and informed by knowledge of the ecosystem in question (such as plant life-history attributes) and inter-relationships with attributes like vegetation condition at the time it is burnt (e.g. young versus old forest). This article is part of the theme issue 'Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration'.
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Affiliation(s)
- David B. Lindenmayer
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT 2601, Australia
| | - Elle J. Bowd
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT 2601, Australia
| | - Philip Gibbons
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT 2601, Australia
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3
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Too hot, too cold, or just right: Can wildfire restore dry forests of the interior Pacific Northwest? PLoS One 2023; 18:e0281927. [PMID: 36848330 PMCID: PMC9970105 DOI: 10.1371/journal.pone.0281927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 02/03/2023] [Indexed: 03/01/2023] Open
Abstract
As contemporary wildfire activity intensifies across the western United States, there is increasing recognition that a variety of forest management activities are necessary to restore ecosystem function and reduce wildfire hazard in dry forests. However, the pace and scale of current, active forest management is insufficient to address restoration needs. Managed wildfire and landscape-scale prescribed burns hold potential to achieve broad-scale goals but may not achieve desired outcomes where fire severity is too high or too low. To explore the potential for fire alone to restore dry forests, we developed a novel method to predict the range of fire severities most likely to restore historical forest basal area, density, and species composition in forests across eastern Oregon. First, we developed probabilistic tree mortality models for 24 species based on tree characteristics and remotely sensed fire severity from burned field plots. We applied these estimates to unburned stands in four national forests to predict post-fire conditions using multi-scale modeling in a Monte Carlo framework. We compared these results to historical reconstructions to identify fire severities with the highest restoration potential. Generally, we found basal area and density targets could be achieved by a relatively narrow range of moderate-severity fire (roughly 365-560 RdNBR). However, single fire events did not restore species composition in forests that were historically maintained by frequent, low-severity fire. Restorative fire severity ranges for stand basal area and density were strikingly similar for ponderosa pine (Pinus ponderosa) and dry mixed-conifer forests across a broad geographic range, in part due to relatively high fire tolerance of large grand (Abies grandis) and white fir (Abies concolor). Our results suggest historical forest conditions created by recurrent fire are not readily restored by single fires and landscapes have likely passed thresholds that preclude the effectiveness of managed wildfire alone as a restoration tool.
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Davis TS, Meddens AJH, Stevens‐Rumann CS, Jansen VS, Sibold JS, Battaglia MA. Monitoring resistance and resilience using carbon trajectories: Analysis of forest management-disturbance interactions. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2704. [PMID: 35801514 PMCID: PMC10077906 DOI: 10.1002/eap.2704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 05/16/2022] [Accepted: 05/24/2022] [Indexed: 05/11/2023]
Abstract
A changing climate is altering ecosystem carbon dynamics with consequences for natural systems and human economies, but there are few tools available for land managers to meaningfully incorporate carbon trajectories into planning efforts. To address uncertainties wrought by rapidly changing conditions, many practitioners adopt resistance and resilience as ecosystem management goals, but these concepts have proven difficult to monitor across landscapes. Here, we address the growing need to understand and plan for ecosystem carbon with concepts of resistance and resilience. Using time series of carbon fixation (n = 103), we evaluate forest management treatments and their relative impacts on resistance and resilience in the context of an expansive and severe natural disturbance. Using subalpine spruce-fir forest with a known management history as a study system, we match metrics of ecosystem productivity (net primary production, g C m-2 year-1 ) with site-level forest structural measurements to evaluate (1) whether past management efforts impacted forest resistance and resilience during a spruce beetle (Dendroctonus rufipennis) outbreak, and (2) how forest structure and physiography contribute to anomalies in carbon trajectories. Our analyses have several important implications. First, we show that the framework we applied was robust for detecting forest treatment impacts on carbon trajectories, closely tracked changes in site-level biomass, and was supported by multiple evaluation methods converging on similar management effects on resistance and resilience. Second, we found that stand species composition, site productivity, and elevation predicted resistance, but resilience was only related to elevation and aspect. Our analyses demonstrate application of a practical approach for comparing forest treatments and isolating specific site and physiographic factors associated with resistance and resilience to biotic disturbance in a forest system, which can be used by managers to monitor and plan for both outcomes. More broadly, the approach we take here can be applied to many scenarios, which can facilitate integrated management and monitoring efforts.
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Affiliation(s)
- Thomas S. Davis
- Forest & Rangeland StewardshipWarner College of Natural Resources, Colorado State UniversityFort CollinsColoradoUSA
- Graduate Degree Program in EcologyColorado State UniversityFort CollinsColoradoUSA
| | - Arjan J. H. Meddens
- School of the EnvironmentCollege of Agricultural, Human, and Natural Resource Sciences, Washington State UniversityPullmanWashingtonUSA
| | - Camille S. Stevens‐Rumann
- Forest & Rangeland StewardshipWarner College of Natural Resources, Colorado State UniversityFort CollinsColoradoUSA
- Colorado Forest Restoration Institute, Colorado State UniversityFort CollinsColoradoUSA
| | - Vincent S. Jansen
- Forest, Rangeland, and Fire Sciences, College of Natural Resources, University of IdahoMoscowIdahoUSA
| | - Jason S. Sibold
- Graduate Degree Program in EcologyColorado State UniversityFort CollinsColoradoUSA
- Anthropology and GeographyCollege of Liberal Arts, Colorado State UniversityFort CollinsColoradoUSA
| | - Mike A. Battaglia
- USDA Forest Service, Rocky Mountain Research StationFort CollinsColoradoUSA
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5
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Ritter SM, Hoffman CM, Battaglia MA, Jain TB. Restoration and fuel hazard reduction result in equivalent reductions in crown fire behavior in dry conifer forests. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2682. [PMID: 35592904 PMCID: PMC9787879 DOI: 10.1002/eap.2682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 01/31/2022] [Accepted: 03/18/2022] [Indexed: 06/15/2023]
Abstract
Over the past several decades, the management of historically frequent-fire forests in the western United States has received significant attention due to the linked ecological and social risks posed by the increased occurrence of large, contiguous patches of high-severity fire. As a result, efforts are underway to simultaneously reduce potential fire and fuel hazards and restore characteristics indicative of historical forest structures and ecological processes that enhance the diversity and quality of wildlife habitat across landscapes. Despite widespread agreement on the need for action, there is a perceived tension among scientists concerning silvicultural treatments that modify stands to optimally reduce potential fire behavior (fuel hazard reduction) versus those that aim to emulate historical forest structures and create structurally complex stands (restoration). In this work, we evaluated thinning treatments in the Black Hills National Forest that exemplify the extremes of a treatment continuum that ranges from fuel hazard reduction to restoration. The goal of this work was to understand how the differing three-dimensional stand structures created by these treatment approaches altered potential fire behavior. Our results indicate that restoration treatments created higher levels of vertical and horizontal structural complexity than the fuel hazard reduction treatments but resulted in similar reductions to potential crown fire behavior. There were some trade-offs identified as the restoration treatments created larger openings, which generated faster mean rates of fire spread; however, these increased spread rates did not translate to higher levels of canopy consumption. Overall, our results suggest that treatments can create vertical and horizontal complexity desired for restoration and wildlife habitat management while reducing fire hazard and that they can be used in concert with traditional fuel hazard reduction treatments to reduce landscape scale fire risk. We also provide some suggestions to land managers seeking to design and implement prescriptions that emulate historical structures and enhance forest complexity.
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Affiliation(s)
- Scott M. Ritter
- Colorado Forest Restoration Institute, Department of Forest and Rangeland Stewardship, Warner College of Natural ResourcesColorado State UniversityFort CollinsColoradoUSA
| | - Chad M. Hoffman
- Department of Forest and Rangeland Stewardship, Warner College of Natural ResourcesColorado State UniversityFort CollinsColoradoUSA
| | - Mike A. Battaglia
- USDA Forest ServiceRocky Mountain Research StationFort CollinsColoradoUSA
| | - Theresa B. Jain
- USDA Forest ServiceRocky Mountain Research StationMoscowIdahoUSA
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6
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Abstract
As the effects of climate change accumulate and intensify, resource managers juggle existing goals and new mandates to operationalize adaptation. Fire managers contend with the direct effects of climate change on resources in addition to climate-induced disruptions to fire regimes and subsequent ecosystem effects. In systems stressed by warming and drying, increased fire activity amplifies the pace of change and scale of severe disturbance events, heightening the urgency for management action. Fire managers are asked to integrate information on climate impacts with their professional expertise to determine how to achieve management objectives in a changing climate with altered fire regimes. This is a difficult task, and managers need support as they incorporate climate adaptation into planning and operations. We present a list of adaptation strategies and approaches specific to fire and climate based on co-produced knowledge from a science–management partnership and pilot-tested in a two-day workshop with natural resource managers and regional stakeholders. This “menu” is a flexible and useful tool for fire managers who need to connect the dots between fire ecology, climate science, adaptation intent, and management implementation. It was created and tested as part of an adaptation framework used widely across the United States and should be applicable and useful in many fire-prone forest ecosystems.
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7
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Furniss TJ, Das AJ, van Mantgem PJ, Stephenson NL, Lutz JA. Crowding, climate, and the case for social distancing among trees. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2507. [PMID: 34870871 DOI: 10.1002/eap.2507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 06/25/2021] [Accepted: 07/30/2021] [Indexed: 06/13/2023]
Abstract
In an emerging era of megadisturbance, bolstering forest resilience to wildfire, insects, and drought has become a central objective in many western forests. Climate has received considerable attention as a driver of these disturbances, but few studies have examined the complexities of climate-vegetation-disturbance interactions. Current strategies for creating resilient forests often rely on retrospective approaches, seeking to impart resilience by restoring historical conditions to contemporary landscapes, but historical conditions are becoming increasingly unattainable amidst modern bioclimatic conditions. What becomes an appropriate benchmark for resilience when we have novel forests, rapidly changing climate, and unprecedented disturbance regimes? We combined two longitudinal datasets-each representing some of the most comprehensive spatially explicit, annual tree mortality data in existence-in a post-hoc factorial design to examine the nonlinear relationships between fire, climate, forest spatial structure, and bark beetles. We found that while prefire drought elevated mortality risk, advantageous local neighborhoods could offset these effects. Surprisingly, mortality risk (Pm ) was higher in crowded local neighborhoods that burned in wet years (Pm = 42%) compared with sparse neighborhoods that burned during drought (Pm = 30%). Risk of beetle attack was also increased by drought, but lower conspecific crowding impeded the otherwise positive interaction between fire and beetle attack. Antecedent fire increased drought-related mortality over short timespans (<7 years) but reduced mortality over longer intervals. These results clarify interacting disturbance dynamics and provide a mechanistic underpinning for forest restoration strategies. Importantly, they demonstrate the potential for managed fire and silvicultural strategies to offset climate effects and bolster resilience to fire, beetles, and drought.
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Affiliation(s)
- Tucker J Furniss
- Wildland Resources Department and Ecology Center, Utah State University, Logan, Utah, USA
- USDA Forest Service, Pacific Northwest Research Station, Wenatchee, Washington, USA
| | - Adrian J Das
- U.S. Geological Survey, Western Ecological Research Center, Three Rivers, California, USA
| | | | - Nathan L Stephenson
- U.S. Geological Survey, Western Ecological Research Center, Three Rivers, California, USA
| | - James A Lutz
- Wildland Resources Department and Ecology Center, Utah State University, Logan, Utah, USA
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8
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Prichard SJ, Hessburg PF, Hagmann RK, Povak NA, Dobrowski SZ, Hurteau MD, Kane VR, Keane RE, Kobziar LN, Kolden CA, North M, Parks SA, Safford HD, Stevens JT, Yocom LL, Churchill DJ, Gray RW, Huffman DW, Lake FK, Khatri‐Chhetri P. Adapting western North American forests to climate change and wildfires: 10 common questions. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02433. [PMID: 34339088 PMCID: PMC9285930 DOI: 10.1002/eap.2433] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/09/2021] [Accepted: 03/22/2021] [Indexed: 05/22/2023]
Abstract
We review science-based adaptation strategies for western North American (wNA) forests that include restoring active fire regimes and fostering resilient structure and composition of forested landscapes. As part of the review, we address common questions associated with climate adaptation and realignment treatments that run counter to a broad consensus in the literature. These include the following: (1) Are the effects of fire exclusion overstated? If so, are treatments unwarranted and even counterproductive? (2) Is forest thinning alone sufficient to mitigate wildfire hazard? (3) Can forest thinning and prescribed burning solve the problem? (4) Should active forest management, including forest thinning, be concentrated in the wildland urban interface (WUI)? (5) Can wildfires on their own do the work of fuel treatments? (6) Is the primary objective of fuel reduction treatments to assist in future firefighting response and containment? (7) Do fuel treatments work under extreme fire weather? (8) Is the scale of the problem too great? Can we ever catch up? (9) Will planting more trees mitigate climate change in wNA forests? And (10) is post-fire management needed or even ecologically justified? Based on our review of the scientific evidence, a range of proactive management actions are justified and necessary to keep pace with changing climatic and wildfire regimes and declining forest heterogeneity after severe wildfires. Science-based adaptation options include the use of managed wildfire, prescribed burning, and coupled mechanical thinning and prescribed burning as is consistent with land management allocations and forest conditions. Although some current models of fire management in wNA are averse to short-term risks and uncertainties, the long-term environmental, social, and cultural consequences of wildfire management primarily grounded in fire suppression are well documented, highlighting an urgency to invest in intentional forest management and restoration of active fire regimes.
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Affiliation(s)
- Susan J. Prichard
- University of Washington School of Environmental and Forest SciencesSeattleWashington98195‐2100USA
| | - Paul F. Hessburg
- University of Washington School of Environmental and Forest SciencesSeattleWashington98195‐2100USA
- U.S. Forest Service PNW Research StationWenatcheeWashington98801USA
| | - R. Keala Hagmann
- University of Washington School of Environmental and Forest SciencesSeattleWashington98195‐2100USA
- Applegate Forestry LLCCorvallisOregon97330USA
| | - Nicholas A. Povak
- U.S. Forest ServicePacific Southwest Research StationInstitute of Forest Genetics2480 Carson RoadPlacervilleCalifornia95667USA
| | - Solomon Z. Dobrowski
- University of Montana College of Forestry and ConservationMissoulaMontana59812USA
| | - Matthew D. Hurteau
- University of New Mexico Biology DepartmentAlbuquerqueNew Mexico87131‐0001USA
| | - Van R. Kane
- University of Washington School of Environmental and Forest SciencesSeattleWashington98195‐2100USA
| | - Robert E. Keane
- U.S. Forest Service Rocky Mountain Research StationMissoula Fire Sciences LaboratoryMissoulaMontana59808USA
| | - Leda N. Kobziar
- Department of Natural Resources and SocietyUniversity of IdahoMoscowIdaho83844USA
| | - Crystal A. Kolden
- School of EngineeringUniversity of California MercedMercedCalifornia95343USA
| | - Malcolm North
- U.S. Forest Service Pacific Southwest Research Station1731 Research ParkDavisCalifornia95618USA
| | - Sean A. Parks
- U.S. Forest Service Aldo Leopold Wilderness Research InstituteMissoulaMontana59801USA
| | - Hugh D. Safford
- U.S. Forest Service Pacific Southwest Research StationAlbanyCalifornia94710USA
| | - Jens T. Stevens
- U.S. Geological Survey Fort Collins Science CenterNew Mexico Landscapes Field StationSanta FeNew Mexico87544USA
| | - Larissa L. Yocom
- Department of Wildland Resources and Ecology CenterUtah State University College of Agriculture and Applied SciencesLoganUtah84322USA
| | - Derek J. Churchill
- Washington State Department of Natural Resources Forest Health ProgramOlympiaWashington98504USA
| | - Robert W. Gray
- R.W. Gray ConsultingChilliwackBritish ColumbiaV2R2N2Canada
| | - David W. Huffman
- Northern Arizona University Ecological Restoration InstituteFlagstaffArizona86011USA
| | - Frank K. Lake
- U.S. Forest Service Pacific Southwest Research StationArcataCalifornia95521USA
| | - Pratima Khatri‐Chhetri
- University of Washington School of Environmental and Forest SciencesSeattleWashington98195‐2100USA
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9
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Jager HI, Long JW, Malison RL, Murphy BP, Rust A, Silva LGM, Sollmann R, Steel ZL, Bowen MD, Dunham JB, Ebersole JL, Flitcroft RL. Resilience of terrestrial and aquatic fauna to historical and future wildfire regimes in western North America. Ecol Evol 2021; 11:12259-12284. [PMID: 34594498 PMCID: PMC8462151 DOI: 10.1002/ece3.8026] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/12/2021] [Accepted: 07/24/2021] [Indexed: 01/08/2023] Open
Abstract
Wildfires in many western North American forests are becoming more frequent, larger, and severe, with changed seasonal patterns. In response, coniferous forest ecosystems will transition toward dominance by fire-adapted hardwoods, shrubs, meadows, and grasslands, which may benefit some faunal communities, but not others. We describe factors that limit and promote faunal resilience to shifting wildfire regimes for terrestrial and aquatic ecosystems. We highlight the potential value of interspersed nonforest patches to terrestrial wildlife. Similarly, we review watershed thresholds and factors that control the resilience of aquatic ecosystems to wildfire, mediated by thermal changes and chemical, debris, and sediment loadings. We present a 2-dimensional life history framework to describe temporal and spatial life history traits that species use to resist wildfire effects or to recover after wildfire disturbance at a metapopulation scale. The role of fire refuge is explored for metapopulations of species. In aquatic systems, recovery of assemblages postfire may be faster for smaller fires where unburned tributary basins or instream structures provide refuge from debris and sediment flows. We envision that more-frequent, lower-severity fires will favor opportunistic species and that less-frequent high-severity fires will favor better competitors. Along the spatial dimension, we hypothesize that fire regimes that are predictable and generate burned patches in close proximity to refuge will favor species that move to refuges and later recolonize, whereas fire regimes that tend to generate less-severely burned patches may favor species that shelter in place. Looking beyond the trees to forest fauna, we consider mitigation options to enhance resilience and buy time for species facing a no-analog future.
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Affiliation(s)
- Henriette I. Jager
- Environmental Sciences DivisionOak Ridge National Laboratory (ORNL)Oak RidgeTNUSA
| | - Jonathan W. Long
- U.S. Department of AgriculturePacific Southwest Research StationDavisCAUSA
| | - Rachel L. Malison
- Flathead Lake Biological StationThe University of MontanaPolsonMTUSA
| | - Brendan P. Murphy
- School of Environmental ScienceSimon Fraser UniversityBurnabyBCCanada
| | - Ashley Rust
- Civil and Environmental Engineering DepartmentColorado School of MinesGoldenCOUSA
| | - Luiz G. M. Silva
- Institute for Land, Water and SocietyCharles Sturt UniversityAlburyNSWAustralia
- Department of CivilEnvironmental and Geomatic EngineeringStocker LabInstitute of Environmental EngineeringETH ZurichZürichSwitzerland
| | - Rahel Sollmann
- Department of Wildlife, Fish, and Conservation BiologyUniversity of California DavisDavisCAUSA
| | - Zachary L. Steel
- Department of Environmental Science, Policy and ManagementUniversity of CaliforniaBerkeleyCAUSA
| | - Mark D. Bowen
- Thomas Gast & Associates Environmental ConsultantsArcataCAUSA
| | - Jason B. Dunham
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science CenterCorvallisORUSA
| | - Joseph L. Ebersole
- Center for Public Health and Environmental AssessmentPacific Ecological Systems DivisionU.S. Environmental Protection AgencyCorvallisORUSA
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10
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Stewart JAE, van Mantgem PJ, Young DJN, Shive KL, Preisler HK, Das AJ, Stephenson NL, Keeley JE, Safford HD, Wright MC, Welch KR, Thorne JH. Effects of postfire climate and seed availability on postfire conifer regeneration. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02280. [PMID: 33331069 DOI: 10.1002/eap.2280] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 07/21/2020] [Accepted: 08/17/2020] [Indexed: 06/12/2023]
Abstract
Large, severe fires are becoming more frequent in many forest types across the western United States and have resulted in tree mortality across tens of thousands of hectares. Conifer regeneration in these areas is limited because seeds must travel long distances to reach the interior of large burned patches and establishment is jeopardized by increasingly hot and dry conditions. To better inform postfire management in low elevation forests of California, USA, we collected 5-yr postfire recovery data from 1,234 study plots in 19 wildfires that burned from 2004-2012 and 18 yrs of seed production data from 216 seed fall traps (1999-2017). We used these data in conjunction with spatially extensive climate, topography, forest composition, and burn severity surfaces to construct taxon-specific, spatially explicit models of conifer regeneration that incorporate climate conditions and seed availability during postfire recovery windows. We found that after accounting for other predictors both postfire and historical precipitation were strong predictors of regeneration, suggesting that both direct effects of postfire moisture conditions and biological inertia from historical climate may play a role in regeneration. Alternatively, postfire regeneration may simply be driven by postfire climate and apparent relationships with historical climate could be spurious. The estimated sensitivity of regeneration to postfire seed availability was strongest in firs and all conifers combined and weaker in pines. Seed production exhibited high temporal variability with seed production varying by over two orders of magnitude among years. Our models indicate that during droughts postfire conifer regeneration declines most substantially in low-to-moderate elevation forests. These findings enhance our mechanistic understanding of forecasted and historically documented shifts in the distribution of trees.
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Affiliation(s)
- Joseph A E Stewart
- Western Ecological Research Center, U.S. Geological Survey, Arcata, California, 95521, USA
- Department of Environmental Science and Policy, UC Davis, Davis, California, 95616, USA
| | - Phillip J van Mantgem
- Western Ecological Research Center, U.S. Geological Survey, Arcata, California, 95521, USA
| | - Derek J N Young
- Department of Plant Sciences, UC Davis, Davis, California, 95616, USA
| | - Kristen L Shive
- Western Ecological Research Center, U.S. Geological Survey, Arcata, California, 95521, USA
| | - Haiganoush K Preisler
- Pacific Southwest Research Station, U.S. Forest Service, Albany, California, 94710, USA
| | - Adrian J Das
- Western Ecological Research Center, U.S. Geological Survey, Three Rivers, California, 93271, USA
| | - Nathan L Stephenson
- Western Ecological Research Center, U.S. Geological Survey, Three Rivers, California, 93271, USA
| | - Jon E Keeley
- Western Ecological Research Center, U.S. Geological Survey, Three Rivers, California, 93271, USA
| | - Hugh D Safford
- Department of Environmental Science and Policy, UC Davis, Davis, California, 95616, USA
- Pacific Southwest Region, U.S. Forest Service, Vallejo, California, 94592, USA
| | - Micah C Wright
- Western Ecological Research Center, U.S. Geological Survey, Arcata, California, 95521, USA
| | - Kevin R Welch
- California Department of Forestry and Fire Protection, Sacramento, California, 94244, USA
| | - James H Thorne
- Department of Environmental Science and Policy, UC Davis, Davis, California, 95616, USA
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11
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Ziegler JP, Hoffman CM, Collins BM, Knapp EE, Mell W(R. Pyric tree spatial patterning interactions in historical and contemporary mixed conifer forests, California, USA. Ecol Evol 2021; 11:820-834. [PMID: 33520169 PMCID: PMC7820164 DOI: 10.1002/ece3.7084] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/23/2020] [Accepted: 11/12/2020] [Indexed: 11/30/2022] Open
Abstract
Tree spatial patterns in dry coniferous forests of the western United States, and analogous ecosystems globally, were historically aggregated, comprising a mixture of single trees and groups of trees. Modern forests, in contrast, are generally more homogeneous and overstocked than their historical counterparts. As these modern forests lack regular fire, pattern formation and maintenance is generally attributed to fire. Accordingly, fires in modern forests may not yield historically analogous patterns. However, direct observations on how selective tree mortality among pre-existing forest structure shapes tree spatial patterns is limited. In this study, we (a) simulated fires in historical and contemporary counterpart plots in a Sierra Nevadan mixed-conifer forest, (b) estimated tree mortality, and (c) examined tree spatial patterns of live trees before and after fire, and of fire-killed trees. Tree mortality in the historical period was clustered and density-dependent, because trees were aggregated and segregated by tree size before fire. Thus, fires maintained an aggregated distribution of tree groups. Tree mortality in the contemporary period was widespread, except for dispersed large trees, because most trees were a part of large, interconnected tree groups. Thus, postfire tree patterns were more uniform and devoid of moderately sized tree groups. Postfire tree patterns in the historical period, unlike the contemporary period, were within the historical range of variability identified for the western United States. This divergence suggests that decades of forest dynamics without significant disturbances have altered the historical means of pyric pattern formation. Our results suggest that ecological silvicultural treatments, such as forest restoration thinnings, which emulate qualities of historical forests may facilitate the reintroduction of fire as a means to reinforce forest structural heterogeneity.
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Affiliation(s)
- Justin P. Ziegler
- Department of Forest & Rangeland StewardshipColorado State UniversityFort CollinsCOUSA
| | - Chad M. Hoffman
- Department of Forest & Rangeland StewardshipColorado State UniversityFort CollinsCOUSA
| | - Brandon M. Collins
- Center for Fire Research & OutreachUniversity of CaliforniaBerkeleyCAUSA
- Pacific Southwest Research StationUS Forest ServiceDavisCAUSA
| | - Eric E. Knapp
- Pacific Southwest Research StationUS Forest ServiceReddingCAUSA
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12
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Stephens SL, Battaglia MA, Churchill DJ, Collins BM, Coppoletta M, Hoffman CM, Lydersen JM, North MP, Parsons RA, Ritter SM, Stevens JT. Forest Restoration and Fuels Reduction: Convergent or Divergent? Bioscience 2020. [DOI: 10.1093/biosci/biaa134] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
For over 20 years, forest fuel reduction has been the dominant management action in western US forests. These same actions have also been associated with the restoration of highly altered frequent-fire forests. Perhaps the vital element in the compatibility of these treatments is that both need to incorporate the salient characteristics that frequent fire produced—variability in vegetation structure and composition across landscapes and the inability to support large patches of high-severity fire. These characteristics can be achieved with both fire and mechanical treatments. The possible key to convergence of fuel reduction and forest restoration strategies is integrated planning that permits treatment design flexibility and a longer-term focus on fire reintroduction for maintenance. With changing climate conditions, long-term forest conservation will probably need to be focused on keeping tree density low enough (i.e., in the lower range of historic variation) for forest conditions to adapt to emerging disturbance patterns and novel ecological processes.
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Affiliation(s)
- Scott L Stephens
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, in Berkeley, California
| | - Mike A Battaglia
- US Department of Agriculture (USDA), Forest Service, Rocky Mountain Research Station, Fort Collins, Colorado
| | - Derek J Churchill
- Forest Health and Resiliency Division of the Washington Department of Natural Resources, Olympia, Washington
| | - Brandon M Collins
- Fire Research and Outreach at the University of California, Berkeley, Berkeley, California, and with the USDA Forest Service, Pacific Southwest Research Station, Davis, California
| | - Michelle Coppoletta
- USDA Forest Service, Sierra Cascade Province Ecology Program, Quincy, California
| | - Chad M Hoffman
- Department of Forest and Rangeland Stewardship, Colorado State University, Fort Collins, Colorado
| | - Jamie M Lydersen
- California Department of Forestry and Fire Protection, Fire and Resource Assessment Program, Sacramento, California
| | - Malcolm P North
- USDA Forest Service, PSW Research Station, Mammoth Lakes, California, and with the Department of Plant Sciences, University of California, Davis, Davis, California
| | | | - Scott M Ritter
- Department of Forest and Rangeland Stewardship, Colorado State University, Fort Collins, Colorado
| | - Jens T Stevens
- US Geological Survey, New Mexico Landscapes Field Station, Santa Fe, New Mexico
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13
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Benefit or Liability? The Ectomycorrhizal Association May Undermine Tree Adaptations to Fire After Long-term Fire Exclusion. Ecosystems 2020. [DOI: 10.1007/s10021-020-00568-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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Busby SU, Moffett KB, Holz A. High‐severity and short‐interval wildfires limit forest recovery in the Central Cascade Range. Ecosphere 2020. [DOI: 10.1002/ecs2.3247] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Sebastian U. Busby
- Department of Geography Portland State University 1721 SW Broadway Portland Oregon97201USA
| | - Kevan B. Moffett
- School of the Environment Washington State University Vancouver Washington98686USA
| | - Andrés Holz
- Department of Geography Portland State University 1721 SW Broadway Portland Oregon97201USA
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15
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Furniss TJ, Larson AJ, Kane VR, Lutz JA. Wildfire and drought moderate the spatial elements of tree mortality. Ecosphere 2020. [DOI: 10.1002/ecs2.3214] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Tucker J. Furniss
- Wildland Resources Department and Ecology Center Utah State University Logan Utah84322USA
| | - Andrew J. Larson
- Wilderness Institute and Department of Forest Management University of Montana Missoula Montana59812USA
| | - Van R. Kane
- School of Environmental and Forest Sciences University of Washington Seattle Washington98195USA
| | - James A. Lutz
- Wildland Resources Department and Ecology Center Utah State University Logan Utah84322USA
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16
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Coop JD, Parks SA, Stevens-Rumann CS, Crausbay SD, Higuera PE, Hurteau MD, Tepley A, Whitman E, Assal T, Collins BM, Davis KT, Dobrowski S, Falk DA, Fornwalt PJ, Fulé PZ, Harvey BJ, Kane VR, Littlefield CE, Margolis EQ, North M, Parisien MA, Prichard S, Rodman KC. Wildfire-Driven Forest Conversion in Western North American Landscapes. Bioscience 2020; 70:659-673. [PMID: 32821066 PMCID: PMC7429175 DOI: 10.1093/biosci/biaa061] [Citation(s) in RCA: 103] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Changing disturbance regimes and climate can overcome forest ecosystem resilience. Following high-severity fire, forest recovery may be compromised by lack of tree seed sources, warmer and drier postfire climate, or short-interval reburning. A potential outcome of the loss of resilience is the conversion of the prefire forest to a different forest type or nonforest vegetation. Conversion implies major, extensive, and enduring changes in dominant species, life forms, or functions, with impacts on ecosystem services. In the present article, we synthesize a growing body of evidence of fire-driven conversion and our understanding of its causes across western North America. We assess our capacity to predict conversion and highlight important uncertainties. Increasing forest vulnerability to changing fire activity and climate compels shifts in management approaches, and we propose key themes for applied research coproduced by scientists and managers to support decision-making in an era when the prefire forest may not return.
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Affiliation(s)
- Jonathan D Coop
- School of Environment and Sustainability, Western Colorado University, Gunnison
| | - Sean A Parks
- Research ecologist with the Aldo Leopold Wilderness Research Institute, Rocky Mountain Research Station, US Forest Service, Missoula, Montana
| | | | - Shelley D Crausbay
- Senior scientist with Conservation Science Partners, Fort Collins, Colorado
| | - Philip E Higuera
- Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, Montana
| | | | - Alan Tepley
- Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta, Canada
| | - Ellen Whitman
- Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta, Canada
| | - Timothy Assal
- Department of Geography, Kent State University, Kent, Ohio
| | - Brandon M Collins
- Fire Research and Outreach, University of California, Berkeley, Berkeley, California, and with the Pacific Southwest Research Station, US Forest Service, in Davis, California
| | - Kimberley T Davis
- Department of Ecosystem and Conservation Sciences, University of Montana, Missoula
| | | | - Donald A Falk
- Natural Resources and the Environment, University of Arizona, Tucson
| | - Paula J Fornwalt
- Rocky Mountain Research Station, US Forest Service, Fort Collins, Colorado
| | - Peter Z Fulé
- School of Forestry, Northern Arizona University, Flagstaff
| | - Brian J Harvey
- School of Environmental and Forest Sciences, University of Washington, Seattle
| | - Van R Kane
- School of Environmental and Forest Sciences, University of Washington, Seattle
| | - Caitlin E Littlefield
- Caitlin Littlefield is a postdoctoral research associate, Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington
| | - Ellis Q Margolis
- US Geological Survey, New Mexico Landscapes Field Station, Santa Fe
| | - Malcolm North
- US Forest Service, Pacific Southwest Research Station, Mammoth Lakes, California
| | - Marc-André Parisien
- Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta, Canada
| | - Susan Prichard
- School of Environmental and Forest Sciences, University of Washington, Seattle
| | - Kyle C Rodman
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison
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17
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Ritter SM, Hoffman CM, Battaglia MA, Stevens‐Rumann CS, Mell WE. Fine‐scale fire patterns mediate forest structure in frequent‐fire ecosystems. Ecosphere 2020. [DOI: 10.1002/ecs2.3177] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Scott M. Ritter
- Department of Forest and Rangeland Stewardship Warner College of Natural Resources Colorado State University Fort Collins Colorado 80523USA
| | - Chad M. Hoffman
- Department of Forest and Rangeland Stewardship Warner College of Natural Resources Colorado State University Fort Collins Colorado 80523USA
| | - Mike A. Battaglia
- Rocky Mountain Research Station USDA Forest Service Fort Collins Colorado 80526USA
| | - Camille S. Stevens‐Rumann
- Department of Forest and Rangeland Stewardship Warner College of Natural Resources Colorado State University Fort Collins Colorado 80523USA
| | - William E. Mell
- Pacific Northwest Research Station USDA Forest Service Seattle Washington 98103USA
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18
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Effectiveness of Restoration Treatments for Reducing Fuels and Increasing Understory Diversity in Shrubby Mixed-Conifer Forests of the Southern Rocky Mountains, USA. FORESTS 2020. [DOI: 10.3390/f11050508] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Exclusion of natural surface fires in warm/dry mixed-conifer forests of the western U.S. has increased potential for stand-replacing crown fires and reduced resilience of these systems to other disturbances, such as drought and insect attack. Tree thinning and the application of prescribed fire are commonly used to restore more resilient ecological conditions, but currently, there is a lack of long-term data with which to evaluate restoration treatment effectiveness in forest types where resprouting shrubs dominate understory communities. At a mixed-conifer site in southwestern Colorado, we compared forest structure and understory vegetation responses to three restoration treatments (thin/burn, burn, and control) over 10 years in a completely randomized and replicated experiment. Forest density, canopy cover, and crown fuel loads were consistently lower, and crown base height was higher, in thin/burn than burn or controls, but the effects diminished over time. Ten years following treatment, >99% of all plant species within both treatments and the control were native in origin. There were no differences between treatments in understory richness, diversity, cover, or surface fuels, but graminoid cover more than doubled in all treatments over the 15-year monitoring period. Similarly, there was more than a 250% increase post-treatment in shrub density, with the greatest increases in the thin/burn treatment. In addition, we saw an increase in the average shrub height for both treatments and the control, with shrub stems >80 cm becoming the dominant size class in the thin/burn treatment. Conifer seedling density was significantly lower in thin/burn compared with burn and control treatments after 10 years. Taken together, these conditions create challenges for managers aiming to reestablish natural fire patterns and sustain mixed-conifer forests. To limit the dominance of resprouting shrubs and facilitate conifer regeneration after overstory thinning and prescribed fire, managers may need to consider new or more intensive approaches to forest restoration, particularly given current and projected climate change.
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19
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20
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Young JD, Thode AE, Huang CH, Ager AA, Fulé PZ. Strategic application of wildland fire suppression in the southwestern United States. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 245:504-518. [PMID: 31153605 DOI: 10.1016/j.jenvman.2019.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 12/14/2018] [Accepted: 01/02/2019] [Indexed: 06/09/2023]
Abstract
Much of the western United States is experiencing longer fire seasons with an increased frequency of high-severity fires and fire risk. Fire managers in the southwestern United States have increased efforts to reduce fire risk by managing more fires to meet resource objectives (e.g. thin forests, reduce hazardous fuel loads, and restore the landscape). However, little is known about the situational circumstances and decision space that inform the strategic response to wildland fire. Using generalized and time-to-event modeling techniques, we examined how fire management decisions are reached in a context informed by weather, burning conditions, and subsequent fire behavior. Modeling results captured daily containment probabilities along a gradient from limiting natural conditions to suppression invoked containment. Results inform fire management decisions, future research efforts, and the simulation of wildland fires with resource objectives.
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Affiliation(s)
- Jesse D Young
- School of Forestry, Northern Arizona University, United States.
| | - Andrea E Thode
- School of Forestry, Northern Arizona University, United States
| | | | - Alan A Ager
- Forest Service, Rocky Mountain Research Station, United States
| | - Pete Z Fulé
- School of Forestry, Northern Arizona University, United States
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21
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22
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Hessburg PF, Miller CL, Parks SA, Povak NA, Taylor AH, Higuera PE, Prichard SJ, North MP, Collins BM, Hurteau MD, Larson AJ, Allen CD, Stephens SL, Rivera-Huerta H, Stevens-Rumann CS, Daniels LD, Gedalof Z, Gray RW, Kane VR, Churchill DJ, Hagmann RK, Spies TA, Cansler CA, Belote RT, Veblen TT, Battaglia MA, Hoffman C, Skinner CN, Safford HD, Salter RB. Climate, Environment, and Disturbance History Govern Resilience of Western North American Forests. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00239] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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23
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We’re Not Doing Enough Prescribed Fire in the Western United States to Mitigate Wildfire Risk. FIRE-SWITZERLAND 2019. [DOI: 10.3390/fire2020030] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Prescribed fire is one of the most widely advocated management practices for reducing wildfire hazard and has a long and rich tradition rooted in indigenous and local ecological knowledge. The scientific literature has repeatedly reported that prescribed fire is often the most effective means of achieving such goals by reducing fuels and wildfire hazard and restoring ecological function to fire-adapted ecosystems in the United States (US) following a century of fire exclusion. This has translated into calls from scientists and policy experts for more prescribed fire, particularly in the Western US, where fire activity has escalated in recent decades. The annual extent of prescribed burning in the Western US remained stable or decreased from 1998 to 2018, while 70% of all prescribed fire was completed primarily by non-federal entities in the Southeastern US. The Bureau of Indian Affairs (BIA) was the only federal agency to substantially increase prescribed fire use, potentially associated with increased tribal self-governance. This suggests that the best available science is not being adopted into management practices, thereby further compounding the fire deficit in the Western US and the potential for more wildfire disasters.
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24
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Dell JE, Salcido DM, Lumpkin W, Richards LA, Pokswinski SM, Loudermilk EL, O'Brien JJ, Dyer LA. Interaction Diversity Maintains Resiliency in a Frequently Disturbed Ecosystem. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00145] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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25
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Higuera PE, Metcalf AL, Miller C, Buma B, McWethy DB, Metcalf EC, Ratajczak Z, Nelson CR, Chaffin BC, Stedman RC, McCaffrey S, Schoennagel T, Harvey BJ, Hood SM, Schultz CA, Black AE, Campbell D, Haggerty JH, Keane RE, Krawchuk MA, Kulig JC, Rafferty R, Virapongse A. Integrating Subjective and Objective Dimensions of Resilience in Fire-Prone Landscapes. Bioscience 2019; 69:379-388. [PMID: 31086421 PMCID: PMC6506416 DOI: 10.1093/biosci/biz030] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Resilience has become a common goal for science-based natural resource management, particularly in the context of changing climate and disturbance regimes. Integrating varying perspectives and definitions of resilience is a complex and often unrecognized challenge to applying resilience concepts to social-ecological systems (SESs) management. Using wildfire as an example, we develop a framework to expose and separate two important dimensions of resilience: the inherent properties that maintain structure, function, or states of an SES and the human perceptions of desirable or valued components of an SES. In doing so, the framework distinguishes between value-free and human-derived, value-explicit dimensions of resilience. Four archetypal scenarios highlight that ecological resilience and human values do not always align and that recognizing and anticipating potential misalignment is critical for developing effective management goals. Our framework clarifies existing resilience theory, connects literature across disciplines, and facilitates use of the resilience concept in research and land-management applications.
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Affiliation(s)
- Philip E Higuera
- Department of Ecosystem and Conservation Sciences at the University of Montana, in Missoula
| | - Alexander L Metcalf
- Department of Society and Conservation at the University of Montana, in Missoula
| | - Carol Miller
- Aldo Leopold Wilderness Research Institute, USDA Forest Service Rocky Mountain Research Station, in Missoula
| | - Brian Buma
- Department of Ecosystem and Conservation Sciences at the University of Montana, in Missoula
| | - David B McWethy
- Department of Earth Sciences at Montana State University, in Bozeman
| | - Elizabeth C Metcalf
- Department of Society and Conservation at the University of Montana, in Missoula
| | - Zak Ratajczak
- Department of Integrative Biology at the University of Wisconsin, in Madison
| | - Cara R Nelson
- Department of Ecosystem and Conservation Sciences at the University of Montana, in Missoula
| | - Brian C Chaffin
- Department of Society and Conservation at the University of Montana, in Missoula
| | - Richard C Stedman
- Department of Natural Resources at Cornell University, in Ithaca, NY
| | - Sarah McCaffrey
- USDA Forest Service Rocky Mountain Research Station, in Fort Collins, CO
| | | | - Brian J Harvey
- Department of Integrative Biology at the University of Colorado, in Denver
- School for Environmental and Forest Sciences at the University of Washington, in Seattle
| | - Sharon M Hood
- USDA Forest Service Rocky Mountain Research Station, in Missoula
| | - Courtney A Schultz
- Department of Forest and Rangeland Stewardship at Colorado State University, in Fort Collins
| | - Anne E Black
- USDA Forest Service Rocky Mountain Research Station, in Missoula
| | - David Campbell
- USFS District Ranger from the Bitterroot National Forest, in Montana
| | - Julia H Haggerty
- Department of Earth Sciences at Montana State University, in Bozeman
| | - Robert E Keane
- USDA Forest Service Rocky Mountain Research Station, in Missoula
| | - Meg A Krawchuk
- Department of Forest Ecosystems and Society at Oregon State University, in Corvallis
| | - Judith C Kulig
- Emeritus professor affiliated with the faculty of Health Sciences at the University of Lethbridge, in Alberta
| | - Rebekah Rafferty
- Department of Society and Conservation at the University of Montana, in Missoula
| | - Arika Virapongse
- Ronin Institute for Independent Scholarship, in Boulder, Colorado
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26
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Parks SA, Dobrowski SZ, Shaw JD, Miller C. Living on the edge: trailing edge forests at risk of fire‐facilitated conversion to non‐forest. Ecosphere 2019. [DOI: 10.1002/ecs2.2651] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Affiliation(s)
- Sean A. Parks
- Aldo Leopold Wilderness Research Institute Rocky Mountain Research Station US Forest Service 790 E. Beckwith Avenue Missoula Montana 59801 USA
| | - Solomon Z. Dobrowski
- W.A. Franke College of Forestry and Conservation University of Montana Missoula Montana 59812 USA
| | - John D. Shaw
- Forest Inventory and Analysis Rocky Mountain Research Station 507 25th Street Ogden Utah 84322 USA
| | - Carol Miller
- Aldo Leopold Wilderness Research Institute Rocky Mountain Research Station US Forest Service 790 E. Beckwith Avenue Missoula Montana 59801 USA
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27
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Shearman TM, Varner JM, Kreye JK. Pyrogenic flowering of
Aristida beyrichiana
following 50 years of fire exclusion. Ecosphere 2019. [DOI: 10.1002/ecs2.2541] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Timothy M. Shearman
- University of Washington School of Environmental and Forest Sciences Seattle Washington 98195 USA
- USDA Forest Service Pacific Wildland Fire Sciences Laboratory Seattle Washington 98103 USA
| | - J. Morgan Varner
- USDA Forest Service Pacific Wildland Fire Sciences Laboratory Seattle Washington 98103 USA
| | - Jesse K. Kreye
- Department of Ecosystem Science and Management The Pennsylvania State University University Park Pennsylvania 16802 USA
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28
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Harvey BJ, Donato DC, Turner MG. Burn me twice, shame on who? Interactions between successive forest fires across a temperate mountain region. Ecology 2018; 97:2272-2282. [PMID: 27859087 DOI: 10.1002/ecy.1439] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/22/2016] [Accepted: 03/25/2016] [Indexed: 02/05/2023]
Abstract
Increasing rates of natural disturbances under a warming climate raise important questions about how multiple disturbances interact. Escalating wildfire activity in recent decades has resulted in some forests re-burning in short succession, but how the severity of one wildfire affects that of a subsequent wildfire is not fully understood. We used a field-validated, satellite-derived, burn-severity atlas to assess interactions between successive wildfires across the US Northern Rocky Mountains a 300,000-km2 region dominated by fire-prone forests. In areas that experienced two wildfires between 1984 and 2010, we asked: (1) How do overall frequency distributions of burn-severity classes compare between first and second fires? (2) In a given location, how does burn severity of the second fire relate to that of the first? (3) Do interactions between successive fires vary by forest zone or the interval between fires? (4) What factors increase the probability of burning twice as stand-replacing fire? Within the study area, 138,061 ha burned twice between 1984 and 2010. Overall, frequency distributions of burn severity classes (low, moderate, high; quantified using relativized remote sensing indices) were similar between the first and second fires; however burn severity was 5-13% lower in second fires on average. Negative interactions between fires were most pronounced in lower-elevation forests and woodlands, when fire intervals were <10 yr, and when burn severity was low in the first fire. When the first fire burned as high severity and fire intervals exceeded 10-12 yr, burn-severity interactions switched from negative to positive, with high-severity fire begetting subsequent high-severity fire. Locations most likely to experience successive stand-replacing fires were high-elevation forests, which are adapted to high-severity fire, and areas conducive to abundant post-fire tree regeneration. Broadly similar severities among short-interval "re-burns" and other wildfires indicate that positive severity feedbacks, an oft-posited agent of ecosystem decline or state shift, are not an inevitable outcome of re-burning. Nonetheless, context-dependent shifts in both the magnitude and direction of wildfire interactions (associated with forest zone, initial burn-severity, and disturbance interval) illustrate complexities in disturbance interactions and can inform management and predictions of future system dynamics.
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Affiliation(s)
- Brian J Harvey
- Department of Geography, University of Colorado-Boulder, Boulder, Colorado, 80309, USA
| | - Daniel C Donato
- Washington Department of Natural Resources, Olympia, Washington, 98504, USA
| | - Monica G Turner
- Department of Zoology, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
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29
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Davis KT, Higuera PE, Sala A. Anticipating fire‐mediated impacts of climate change using a demographic framework. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13132] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kimberley T. Davis
- Department of Ecosystem and Conservation Sciences University of Montana Missoula Montana
| | - Philip E. Higuera
- Department of Ecosystem and Conservation Sciences University of Montana Missoula Montana
| | - Anna Sala
- Division of Biological Sciences University of Montana Missoula Montana
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30
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Fire regimes approaching historic norms reduce wildfire‐facilitated conversion from forest to non‐forest. Ecosphere 2018. [DOI: 10.1002/ecs2.2182] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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31
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Breininger DR, Foster TE, Carter GM, Duncan BW, Stolen ED, Lyon JE. The effects of vegetative type, edges, fire history, rainfall, and management in fire-maintained habitat. Ecosphere 2018. [DOI: 10.1002/ecs2.2120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- David R. Breininger
- NASA Ecology Program; John F Kennedy Space Center; IMSS-300 Kennedy Space Center Florida 32899 USA
| | - Tammy E. Foster
- NASA Ecology Program; John F Kennedy Space Center; IMSS-300 Kennedy Space Center Florida 32899 USA
| | - Geoffrey M. Carter
- NASA Ecology Program; John F Kennedy Space Center; IMSS-300 Kennedy Space Center Florida 32899 USA
| | - Brean W. Duncan
- NASA Ecology Program; John F Kennedy Space Center; IMSS-300 Kennedy Space Center Florida 32899 USA
| | - Eric D. Stolen
- NASA Ecology Program; John F Kennedy Space Center; IMSS-300 Kennedy Space Center Florida 32899 USA
| | - James E. Lyon
- Merritt Island National Wildlife Refuge; Titusville Florida 32901 USA
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32
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Mixed-Severity Fire Fosters Heterogeneous Spatial Patterns of Conifer Regeneration in a Dry Conifer Forest. FORESTS 2018. [DOI: 10.3390/f9010045] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Collins BM, Fry DL, Lydersen JM, Everett R, Stephens SL. Impacts of different land management histories on forest change. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:2475-2486. [PMID: 28873261 DOI: 10.1002/eap.1622] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 06/07/2017] [Accepted: 07/18/2017] [Indexed: 06/07/2023]
Abstract
Many western North American forest types have experienced considerable changes in ecosystem structure, composition, and function as a result of both fire exclusion and timber harvesting. These two influences co-occurred over a large portion of dry forests, making it difficult to know the strength of either one on its own or the potential for an interaction between the two. In this study, we used contemporary remeasurements of a systematic historical forest inventory to investigate forest change in the Sierra Nevada. The historical data opportunistically spanned a significant land management agency boundary, which protected part of the inventory area from timber harvesting. This allowed for a robust comparison of forest change between logged and unlogged areas. In addition, we assessed the effects of recent management activities aimed at forest restoration relative to the same areas historically, and to other areas without recent management. Based on analyses of 22,007 trees (historical, 9,573; contemporary, 12,434), live basal area and tree density significantly increased from 1911 to the early 2000s in both logged and unlogged areas. Both shrub cover and the proportion of live basal area occupied by pine species declined from 1911 to the early 2000s in both areas, but statistical significance was inconsistent. The most notable difference between logged and unlogged areas was in the density of large trees, which declined significantly in logged areas, but was unchanged in unlogged areas. Recent management activities had a varied impact on the forest structure and composition variables analyzed. In general, areas with no recent management activities experienced the greatest change from 1911 to the early 2000s. If approximating historical forest conditions is a land management goal the documented changes in forest structure and composition from 1911 to the early 2000s indicate that active restoration, including fire use and mechanical thinning, is needed in many areas.
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Affiliation(s)
- Brandon M Collins
- Center for Fire Research and Outreach, University of California, Berkeley, California, 94720-3114, USA
| | - Danny L Fry
- Ecosystem Sciences Division, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, 94720, USA
| | - Jamie M Lydersen
- Pacific Southwest Research Station, USDA Forest Service, Davis, California, 95618, USA
| | - Richard Everett
- Ecosystem Sciences Division, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, 94720, USA
- Department of Natural Resources, Salish Kootenai College, 58138 Highway 93, P.O. Box 70, Pablo, Montana, 59855, USA
| | - Scott L Stephens
- Ecosystem Sciences Division, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, 94720, USA
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Harris L, Taylor AH. Previous burns and topography limit and reinforce fire severity in a large wildfire. Ecosphere 2017. [DOI: 10.1002/ecs2.2019] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Lucas Harris
- Department of Geography; Pennsylvania State University; 302 Walker Building University Park Pennsylvania 16802 USA
| | - Alan H. Taylor
- Department of Geography; Pennsylvania State University; 302 Walker Building University Park Pennsylvania 16802 USA
- Earth and Environmental Systems Institute; Pennsylvania State University; 2217 Earth-Engineering Sciences Building University Park Pennsylvania 16802 USA
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O'Connor CD, Falk DA, Lynch AM, Swetnam TW, Wilcox CP. Disturbance and productivity interactions mediate stability of forest composition and structure. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:900-915. [PMID: 28029193 DOI: 10.1002/eap.1492] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 12/06/2016] [Accepted: 12/12/2016] [Indexed: 06/06/2023]
Abstract
Fire is returning to many conifer-dominated forests where species composition and structure have been altered by fire exclusion. Ecological effects of these fires are influenced strongly by the degree of forest change during the fire-free period. Response of fire-adapted species assemblages to extended fire-free intervals is highly variable, even in communities with similar historical fire regimes. This variability in plant community response to fire exclusion is not well understood; however, ecological mechanisms such as individual species' adaptations to disturbance or competition and underlying site characteristics that facilitate or impede establishment and growth have been proposed as potential drivers of assemblage response. We used spatially explicit dendrochronological reconstruction of tree population dynamics and fire regimes to examine the influence of historical disturbance frequency (a proxy for adaptation to disturbance or competition), and potential site productivity (a proxy for underlying site characteristics) on the stability of forest composition and structure along a continuous ecological gradient of pine, dry mixed-conifer, mesic mixed-conifer, and spruce-fir forests following fire exclusion. While average structural density increased in all forests, species composition was relatively stable in the lowest productivity pine-dominated and highest productivity spruce-fir-dominated sites immediately following fire exclusion and for the next 100 years, suggesting site productivity as a primary control on species composition and structure in forests with very different historical fire regimes. Species composition was least stable on intermediate productivity sites dominated by mixed-conifer forests, shifting from primarily fire-adapted species to competition-adapted, fire-sensitive species within 20 years of fire exclusion. Rapid changes to species composition and stand densities have been interpreted by some as evidence of high-severity fire. We demonstrate that the very different ecological process of fire exclusion can produce similar changes by shifting selective pressures from disturbance-mediated to productivity-mediated controls. Restoring disturbance-adapted species composition and structure to intermediate productivity forests may help to buffer them against projected increasing temperatures, lengthening fire seasons, and more frequent and prolonged moisture stress. Fewer management options are available to promote adaptation in forest assemblages historically constrained by underlying site productivity.
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Affiliation(s)
- Christopher D O'Connor
- School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona, 85721, USA
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona, 85721, USA
| | - Donald A Falk
- School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona, 85721, USA
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona, 85721, USA
| | - Ann M Lynch
- U.S. Forest Service, Rocky Mountain Research Station, Tucson, Arizona, 85721, USA
| | - Thomas W Swetnam
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona, 85721, USA
| | - Craig P Wilcox
- U.S. Forest Service, Coronado National Forest, Safford, Arizona, 85546, USA
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36
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Becker KML, Lutz JA. Can low‐severity fire reverse compositional change in montane forests of the Sierra Nevada, California, USA? Ecosphere 2016. [DOI: 10.1002/ecs2.1484] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Kendall M. L. Becker
- Wildland Resources DepartmentUtah State University 5230 Old Main Hill Logan Utah 84322 USA
| | - James A. Lutz
- Wildland Resources DepartmentUtah State University 5230 Old Main Hill Logan Utah 84322 USA
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37
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Stephens SL, Miller JD, Collins BM, North MP, Keane JJ, Roberts SL. Wildfire impacts on California spotted owl nesting habitat in the Sierra Nevada. Ecosphere 2016. [DOI: 10.1002/ecs2.1478] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Scott L. Stephens
- Division of Ecosystem Science Department of Environmental Science, Policy, and Management University of California 130 Mulford Hall Berkeley California 94720 USA
| | - Jay D. Miller
- USDA Forest Service Pacific Southwest Region, Fire and Aviation Management McClellan California 95652 USA
| | - Brandon M. Collins
- Pacific Southwest Research Station USDA Forest Service Davis California 95618 USA
- Center for Fire Research and Outreach University of California Berkeley California 94720 USA
| | - Malcolm P. North
- Pacific Southwest Research Station USDA Forest Service Davis California 95618 USA
| | - John J. Keane
- Pacific Southwest Research Station USDA Forest Service Davis California 95618 USA
| | - Susan L. Roberts
- University of California, Merced, Sierra Nevada Research Station 7799 Chilnualna Falls Road Wawona California 95389 USA
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38
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Stephens SL, Collins BM, Biber E, Fulé PZ. U.S.
federal fire and forest policy: emphasizing resilience in dry forests. Ecosphere 2016. [DOI: 10.1002/ecs2.1584] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Scott L. Stephens
- Division of Ecosystem ScienceDepartment of Environmental Science, Policy, and ManagementUniversity of California 130 Mulford Hall Berkeley California 94720 USA
| | - Brandon M. Collins
- Center for Fire Research and OutreachUniversity of California Berkeley California 94720 USA
| | - Eric Biber
- University of California, BerkeleySchool of Law 436 North Addition Berkeley California 94720 USA
| | - Peter Z. Fulé
- School of ForestryCollege of Engineering, Forestry, and Natural SciencesNorthern Arizona University Flagstaff Arizona 86011 USA
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Flatley WT, Fulé PZ. Are historical fire regimes compatible with future climate? Implications for forest restoration. Ecosphere 2016. [DOI: 10.1002/ecs2.1471] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- William T. Flatley
- School of Forestry Northern Arizona University PO Box 15018 Flagstaff Arizona 86011 USA
| | - Peter Z. Fulé
- School of Forestry Northern Arizona University PO Box 15018 Flagstaff Arizona 86011 USA
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40
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Hood SM, Baker S, Sala A. Fortifying the forest: thinning and burning increase resistance to a bark beetle outbreak and promote forest resilience. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:1984-2000. [PMID: 27755724 DOI: 10.1002/eap.1363] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 03/10/2016] [Accepted: 03/14/2016] [Indexed: 05/26/2023]
Abstract
Fire frequency in low-elevation coniferous forests in western North America has greatly declined since the late 1800s. In many areas, this has increased tree density and the proportion of shade-tolerant species, reduced resource availability, and increased forest susceptibility to forest insect pests and high-severity wildfire. In response, treatments are often implemented with the goal of increasing ecosystem resilience by increasing resistance to disturbance. We capitalized on an existing replicated study of fire and stand density treatments in a ponderosa pine (Pinus ponderosa)-Douglas-fir (Pseudotsuga menziesii) forest in western Montana, USA, that experienced a naturally occurring mountain pine beetle (MPB; Dendroctonus ponderosae) outbreak 5 yr after implementation of fuels treatments. We explored whether treatment effects on tree-level defense and stand structure affected resistance to MPB. Mortality from MPB was highest in the denser, untreated control and burn-only treatments, with approximately 50% and 39%, respectively, of ponderosa pine killed during the outbreak, compared to almost no mortality in the thin-only and thin-burn treatments. Thinning treatments, with or without fire, dramatically increased tree growth and resin ducts relative to control and burn-only treatments. Prescribed burning did not increase resin ducts but did cause changes in resin chemistry that may have affected MPB communication and lowered attack success. While ponderosa pine remained dominant in the thin and thin-burn treatments after the outbreak, the high pine mortality in the control and burn-only treatment caused a shift in species dominance to Douglas-fir. The high Douglas-fir component in the control and burn-only treatments due to 20th century fire exclusion, coupled with high pine mortality from MPB, has likely reduced resilience of this forest beyond the ability to return to a ponderosa pine-dominated system in the absence of further fire or mechanical treatment. Our results show treatments designed to increase resistance to high-severity fire in ponderosa pine-dominated forests in the Northern Rockies can also increase resistance to MPB, even during an outbreak. This study suggests that fuel and restoration treatments in fire-dependent ponderosa pine forests that reduce tree density increase ecosystem resilience in the short term, while the reintroduction of fire is important for long-term resilience.
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Affiliation(s)
- Sharon M Hood
- Fire, Fuel and Smoke Science Program, Rocky Mountain Research Station, USDA Forest Service, 5775 Highway 10 W, Missoula, Montana, 59808, USA.
- Division of Biological Sciences, 32 Campus Drive, University of Montana, Missoula, Montana, 59812, USA.
| | - Stephen Baker
- Fire, Fuel and Smoke Science Program, Rocky Mountain Research Station, USDA Forest Service, 5775 Highway 10 W, Missoula, Montana, 59808, USA
| | - Anna Sala
- Division of Biological Sciences, 32 Campus Drive, University of Montana, Missoula, Montana, 59812, USA
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41
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Stevens-Rumann C, Morgan P. Repeated wildfires alter forest recovery of mixed-conifer ecosystems. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:1842-1853. [PMID: 27755710 DOI: 10.1890/15-1521.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 12/09/2015] [Accepted: 01/28/2016] [Indexed: 06/06/2023]
Abstract
Most models project warmer and drier climates that will contribute to larger and more frequent wildfires. However, it remains unknown how repeated wildfires alter post-fire successional patterns and forest structure. Here, we test the hypothesis that the number of wildfires, as well as the order and severity of wildfire events interact to alter forest structure and vegetation recovery and implications for vegetation management. In 2014, we examined forest structure, composition, and tree regeneration in stands that burned 1-18 yr before a subsequent 2007 wildfire. Three important findings emerged: (1) Repeatedly burned forests had 15% less woody surface fuels and 31% lower tree seedling densities compared with forests that only experienced one recent wildfire. These repeatedly burned areas are recovering differently than sites burned once, which may lead to alternative ecosystem structure. (2) Order of burn severity (high followed by low severity compared with low followed by high severity) did influence forest characteristics. When low burn severity followed high, forests had 60% lower canopy closure and total basal area with 92% fewer tree seedlings than when high burn severity followed low. (3) Time between fires had no effect on most variables measured following the second fire except large woody fuels, canopy closure and tree seedling density. We conclude that repeatedly burned areas meet many vegetation management objectives of reduced fuel loads and moderate tree seedling densities. These differences in forest structure, composition, and tree regeneration have implications not only for the trajectories of these forests, but may reduce fire intensity and burn severity of subsequent wildfires and may be used in conjunction with future fire suppression tactics.
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Affiliation(s)
- Camille Stevens-Rumann
- University of Idaho, Department of Forest, Rangeland and Fire Sciences, Moscow, Idaho, 83844 USA .
| | - Penelope Morgan
- University of Idaho, Department of Forest, Rangeland and Fire Sciences, Moscow, Idaho, 83844 USA
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42
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Donato DC, Harvey BJ, Turner MG. Regeneration of montane forests 24 years after the 1988 Yellowstone fires: A fire‐catalyzed shift in lower treelines? Ecosphere 2016. [DOI: 10.1002/ecs2.1410] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- Daniel C. Donato
- Washington State Department of Natural Resources Box 47014 Olympia Washington 98504 USA
- School of Environmental and Forest Sciences, University of Washington Seattle Washington 98195 USA
| | - Brian J. Harvey
- Department of Geography University of Colorado Boulder Colorado 80309 USA
| | - Monica G. Turner
- Department of Zoology University of Wisconsin Madison Wisconsin 53706 USA
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43
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Ganzlin PW, Gundale MJ, Becknell RE, Cleveland CC. Forest restoration treatments have subtle long-term effects on soil C and N cycling in mixed conifer forests. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:1503-1516. [PMID: 27755759 DOI: 10.1002/15-1100] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 10/20/2015] [Accepted: 11/06/2015] [Indexed: 06/06/2023]
Abstract
Decades of fire suppression following extensive timber harvesting have left much of the forest in the intermountain western United States exceedingly dense, and forest restoration techniques (i.e., thinning and prescribed fire) are increasingly being used in an attempt to mitigate the effects of severe wildfire, to enhance tree growth and regeneration, and to stimulate soil nutrient cycling. While many of the short-term effects of forest restoration have been established, the long-term effects on soil biogeochemical and ecosystem processes are largely unknown. We assessed the effects of commonly used forest restoration treatments (thinning, burning, and thinning + burning) on nutrient cycling and other ecosystem processes 11 yr after restoration treatments were implemented in a ponderosa pine (Pinus ponderosa var. scopulorum)/Douglas fir (Pseudotsuga menziesii var. glauca) forest at the Lubrecht Fire and Fire Surrogates Study (FFS) site in western Montana, USA. Despite short-term (<3 yr) increases in soil inorganic nitrogen (N) pools and N cycling rates following prescribed fire, long-term soil N pools and N mineralization rates showed only subtle differences from untreated control plots. Similarly, despite a persistent positive correlation between fuels consumed in prescribed burns and several metrics of N cycling, variability in inorganic N pools decreased significantly since treatments were implemented, indicating a decline in N spatial heterogeneity through time. However, rates of net nitrification remain significantly higher in a thin + burn treatment relative to other treatments. Short-term declines in forest floor carbon (C) pools have persisted in the thin + burn treatment, but there were no significant long-term differences among treatments in extractable soil phosphorus (P). Finally, despite some short-term differences, long-term foliar nutrient concentrations, litter decomposition rates, and rates of free-living N fixation in the experimental plots were not different from control plots, suggesting nutrient cycles and ecosystem processes in temperate coniferous forests are resilient to disturbance following long periods of fire suppression. Overall, this study provides forest managers and policymakers valuable information showing that the effects of these commonly used restoration prescriptions on soil nutrient cycling are ephemeral and that use of repeated treatments (i.e., frequent fire) will be necessary to ensure continued restoration success.
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Affiliation(s)
- Peter W Ganzlin
- Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, University of Montana, Missoula, Montana, 59812, USA
| | - Michael J Gundale
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, 901 83, Sweden
| | - Rachel E Becknell
- Department of Biology, University of Missouri-St. Louis, St. Louis, Missouri, 63121, USA
| | - Cory C Cleveland
- Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, University of Montana, Missoula, Montana, 59812, USA
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44
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Coppoletta M, Merriam KE, Collins BM. Post-fire vegetation and fuel development influences fire severity patterns in reburns. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:686-699. [PMID: 27411243 DOI: 10.1890/15-0225] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In areas where fire regimes and forest structure have been dramatically altered, there is increasing concern that contemporary fires have the potential to set forests on a positive feedback trajectory with successive reburns, one in which extensive stand-replacing fire could promote more stand-replacing fire. Our study utilized an extensive set of field plots established following four fires that occurred between 2000 and 2010 in the northern Sierra Nevada, California, USA that were subsequently reburned in 2012. The information obtained from these field plots allowed for a unique set of analyses investigating the effect of vegetation, fuels, topography, fire weather, and forest management on reburn severity. We also examined the influence of initial fire severity and time since initial fire on influential predictors of reburn severity. Our results suggest that high- to moderate-severity fire in the initial fires led to an increase in standing snags and shrub vegetation, which in combination with severe fire weather promoted high-severity fire effects in the subsequent reburn. Although fire behavior is largely driven by weather, our study demonstrates that post-fire vegetation composition and structure are also important drivers of reburn severity. In the face of changing climatic regimes and increases in extreme fire weather, these results may provide managers with options to create more fire-resilient ecosystems. In areas where frequent high-severity fire is undesirable, management activities such as thinning, prescribed fire, or managed wildland fire can be used to moderate fire behavior not only prior to initial fires, but also before subsequent reburns.
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45
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Coop JD, Parks SA, McClernan SR, Holsinger LM. Influences of prior wildfires on vegetation response to subsequent fire in a reburned Southwestern landscape. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:346-354. [PMID: 27209778 DOI: 10.1890/15-0775] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Large and severe wildfires have raised concerns about the future of forested landscapes in the southwestern United States, especially under repeated burning. In 2011, under extreme weather and drought conditions, the Las Conchas fire burned over several previous burns as well as forests not recently exposed to fire. Our purpose was to examine the influences of prior wildfires on plant community composition and structure, subsequent burn severity, and vegetation response. To assess these relationships, we used satellite-derived measures of burn severity and a nonmetric multidimensional scaling of pre- and post- Las Conchas field samples. Earlier burns were associated with shifts from forested sites to open savannas and meadows, oak scrub, and ruderal communities. These non-forested vegetation types exhibited both resistance to subsequent fire, measured by reduced burn severity, and resilience to reburning, measured by vegetation recovery relative to forests not exposed to recent prior fire. Previous shifts toward non-forested states were strongly reinforced by reburning. Ongoing losses of forests and their ecological values confirm the need for restoration interventions. However, given future wildfire and climate projections, there may also be opportunities presented by transformations toward fire-resistant and resilient vegetation types within portions of the landscape.
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46
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Weathers KC, Groffman PM, Van Dolah E, Bernhardt E, Grimm NB, McMahon K, Schimel J, Paolisso M, Maranger R, Baer S, Brauman K, Hinckley E. Frontiers in Ecosystem Ecology from a Community Perspective: The Future is Boundless and Bright. Ecosystems 2016. [DOI: 10.1007/s10021-016-9967-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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47
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Parks SA, Holsinger LM, Miller C, Nelson CR. Wildland fire as a self-regulating mechanism: the role of previous burns and weather in limiting fire progression. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2015; 25:1478-92. [PMID: 26552258 DOI: 10.1890/14-1430.1] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Theory suggests that natural fire regimes can result in landscapes that are both self-regulating and resilient to fire. For example, because fires consume fuel, they may create barriers to the spread of future fires, thereby regulating fire size. Top-down controls such as weather, however, can weaken this effect. While empirical examples demonstrating this pattern-process feedback between vegetation and fire exist, they have been geographically limited or did not consider the influence of time between fires and weather. The availability of remotely sensed data identifying fire activity over the last four decades provides an opportunity to explicitly quantify-the ability of wildland fire to limit the progression of subsequent fire. Furthermore, advances in fire progression mapping now allow an evaluation of how daily weather as a top-down control modifies this effect. In this study, we evaluated the ability of wildland fire to create barriers that limit the spread of subsequent fire along a gradient representing time between fires in four large study areas in the western United States. Using fire progression maps in conjunction with weather station data, we also evaluated the influence of daily weather. Results indicate that wildland fire does limit subsequent fire spread in all four study areas, but this effect decays over time; wildland fire no longer limits subsequent fire spread 6-18 years after fire, depending on the study area. We also found that the ability of fire to regulate, subsequent fire progression was substantially reduced under extreme conditions compared to moderate weather conditions in all four study areas. This study increases understanding of the spatial feedbacks that can lead to self-regulating landscapes as well as the effects of top-down controls, such as weather, on these feedbacks. Our results will be useful to managers who seek to restore natural fire regimes or to exploit recent burns when managing fire.
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48
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Belote RT, Dietz MS, Aplet GH. Allocating Untreated “Controls” in the National Wilderness Preservation System as a Climate Adaptation Strategy: A Case Study from the Flathead National Forest, Montana. NORTHWEST SCIENCE 2015. [DOI: 10.3955/046.089.0311] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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49
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Morrison KD, Kolden CA. Modeling the impacts of wildfire on runoff and pollutant transport from coastal watersheds to the nearshore environment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2015; 151:113-23. [PMID: 25549866 DOI: 10.1016/j.jenvman.2014.12.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Revised: 12/07/2014] [Accepted: 12/10/2014] [Indexed: 05/05/2023]
Abstract
Wildfire is a common disturbance that can significantly alter vegetation in watersheds and affect the rate of sediment and nutrient transport to adjacent nearshore oceanic environments. Changes in runoff resulting from heterogeneous wildfire effects are not well-understood due to both limitations in the field measurement of runoff and temporally-limited spatial data available to parameterize runoff models. We apply replicable, scalable methods for modeling wildfire impacts on sediment and nonpoint source pollutant export into the nearshore environment, and assess relationships between wildfire severity and runoff. Nonpoint source pollutants were modeled using a GIS-based empirical deterministic model parameterized with multi-year land cover data to quantify fire-induced increases in transport to the nearshore environment. Results indicate post-fire concentration increases in phosphorus by 161 percent, sediments by 350 percent and total suspended solids (TSS) by 53 percent above pre-fire years. Higher wildfire severity was associated with the greater increase in exports of pollutants and sediment to the nearshore environment, primarily resulting from the conversion of forest and shrubland to grassland. This suggests that increasing wildfire severity with climate change will increase potential negative impacts to adjacent marine ecosystems. The approach used is replicable and can be utilized to assess the effects of other types of land cover change at landscape scales. It also provides a planning and prioritization framework for management activities associated with wildfire, including suppression, thinning, and post-fire rehabilitation, allowing for quantification of potential negative impacts to the nearshore environment in coastal basins.
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Affiliation(s)
| | - Crystal A Kolden
- Department of Geography, University of Idaho, Moscow, ID 83844, USA.
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50
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Cansler CA, McKenzie D. Climate, fire size, and biophysical setting control fire severity and spatial pattern in the northern Cascade Range, USA. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2014; 24:1037-1056. [PMID: 25154095 DOI: 10.1890/13-1077.1] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Warmer and drier climate over the past few decades has brought larger fire sizes and increased annual area burned in forested ecosystems of western North America, and continued increases in annual area burned are expected due to climate change. As warming continues, fires may also increase in severity and produce larger contiguous patches of severely burned areas. We used remotely sensed burn-severity data from 125 fires in the northern Cascade Range of Washington, USA, to explore relationships between fire size, severity, and the spatial pattern of severity. We examined relationships between climate and the annual area burned and the size of wildfires over a 25-year period. We tested the hypothesis that increased fire size is commensurate with increased burn severity and increased spatial aggregation of severely burned areas. We also asked how local ecological controls might modulate these relationships by comparing results over the whole study area (the northern Cascade Range) to those from four ecological subsections within it. We found significant positive relationships between climate and fire size, and between fire size and the proportion of high severity and spatial-pattern metrics that quantify the spatial aggregation of high-severity areas within fires, but the strength and significance of these relationships varied among the four subsections. In areas with more contiguous subalpine forests and less complex topography, the proportion and spatial aggregation of severely burned areas were more strongly correlated with fire size. If fire sizes increase in a warming climate, changes in the extent, severity, and spatial pattern of fire regimes are likely to be more pronounced in higher-severity fire regimes with less complex topography and more continuous fuels.
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