An estimated 1.2 billion U.S. dollars was spent to mitigate wildfires in California in the fiscal years ending June 30, 2022. This would constitute a decrease compared to the previous year, but still significantly above wildfire suppression costs in the years between 2012 and 2020. Spending on wildfire suppression increased significantly as forest and wildland fires have grown in scale and intensity.

This statistic illustrates the cost of California wildfires in 2017, by cause. In that year, wildfires caused byelectrical power systems cost over 12 billion U.S. dollars, while wildfires caused by lightning cost the state roughly 18,600 U.S. dollars.

The Wildland Fire Interagency Geospatial Services (WFIGS) Group provides authoritative geospatial data products under the interagency Wildland Fire Data Program. Hosted in the National Interagency Fire Center ArcGIS Online Organization (The NIFC Org), WFIGS provides both internal and public facing data, accessible in a variety of formats.This service includes perimeters for wildland fire incidents that meet the following criteria:Categorized in the IRWIN (Integrated Reporting of Wildland Fire Information) integration service as a Wildfire (WF) or Prescribed Fire (RX) recordFire Discovery Date is in the year 2025Is Valid and not "quarantined" in IRWIN due to potential conflicts with other recordsAttribution of the source polygon is set to a Feature Access of Public, a Feature Status of Approved, and an Is Visible setting of YesPerimeters are not available for every incident. For a complete set of features that meet the same IRWIN criteria, see the 2025 Wildland Fire Incident Locations to Date service.No "fall-off" rules are applied to this service. Criteria were determined by an NWCG Geospatial Subcommittee task group. Data are refreshed every 5 minutes. Changes in the perimeter source may take up to 15 minutes to display.Perimeters are pulled from multiple sources with rules in place to ensure the most current or most authoritative shape is used.Attributes and their definitions can be found below. More detail about the NWCG Wildland Fire Event Polygon standard can be found here.Attributes:poly_SourceOIDThe OBJECTID value of the source record in the source dataset providing the polygon.poly_IncidentNameThe incident name as stored in the polygon source record.poly_MapMethodThe mapping method with which the polygon was derived.poly_GISAcresThe acreage of the polygon as stored in the polygon source record.poly_CreateDateSystem generated date for the date time the source polygon record was created (stored in UTC).poly_DateCurrentSystem generated date for the date time the source polygon record was last edited (stored in UTC).poly_PolygonDateTimeRepresents the date time that the polygon data was captured.poly_IRWINIDIRWIN ID stored in the polygon record.poly_FORIDFORID stored in the polygon record.poly_Acres_AutoCalcSystem calculated acreage of the polygon (geodesic WGS84 acres).poly_SourceGlobalIDThe GlobalID value of the source record in the source dataset providing the polygon.poly_SourceThe source dataset providing the polygon.attr_SourceOIDThe OBJECTID value of the source record in the source dataset providing the attribution.attr_ABCDMiscA FireCode used by USDA FS to track and compile cost information for emergency initial attack fire suppression expenditures. for A, B, C & D size class fires on FS lands.attr_ADSPermissionStateIndicates the permission hierarchy that is currently being applied when a system utilizes the UpdateIncident operation.attr_ContainmentDateTimeThe date and time a wildfire was declared contained. attr_ControlDateTimeThe date and time a wildfire was declared under control.attr_CreatedBySystemArcGIS Server Username of system that created the IRWIN Incident record.attr_IncidentSizeReported for a fire. The minimum size is 0.1.attr_DiscoveryAcresAn estimate of acres burning upon the discovery of the fire. More specifically when the fire is first reported by the first person that calls in the fire. The estimate should include number of acres within the current perimeter of a specific, individual incident, including unburned and unburnable islands.attr_DispatchCenterIDA unique identifier for a dispatch center responsible for supporting the incident.attr_EstimatedCostToDateThe total estimated cost of the incident to date.attr_FinalAcresReported final acreage of incident.attr_FFReportApprovedByTitleThe title of the person that approved the final fire report for the incident.attr_FFReportApprovedByUnitNWCG Unit ID associated with the individual who approved the final report for the incident.attr_FFReportApprovedDateThe date that the final fire report was approved for the incident.attr_FireBehaviorGeneralA general category describing the manner in which the fire is currently reacting to the influences of fuel, weather, and topography. attr_FireBehaviorGeneral1A more specific category further describing the general fire behavior (manner in which the fire is currently reacting to the influences of fuel, weather, and topography). attr_FireBehaviorGeneral2A more specific category further describing the general fire behavior (manner in which the fire is currently reacting to the influences of fuel, weather, and topography). attr_FireBehaviorGeneral3A more specific category further describing the general fire behavior (manner in which the fire is currently reacting to the influences of fuel, weather, and topography). attr_FireCauseBroad classification of the reason the fire occurred identified as human, natural or unknown. attr_FireCauseGeneralAgency or circumstance which started a fire or set the stage for its occurrence; source of a fire's ignition. For statistical purposes, fire causes are further broken into specific causes. attr_FireCauseSpecificA further categorization of each General Fire Cause to indicate more specifically the agency or circumstance which started a fire or set the stage for its occurrence; source of a fire's ignition. attr_FireCodeA code used within the interagency wildland fire community to track and compile cost information for emergency fire suppression expenditures for the incident. attr_FireDepartmentIDThe U.S. Fire Administration (USFA) has created a national database of Fire Departments. Most Fire Departments do not have an NWCG Unit ID and so it is the intent of the IRWIN team to create a new field that includes this data element to assist the National Association of State Foresters (NASF) with data collection.attr_FireDiscoveryDateTimeThe date and time a fire was reported as discovered or confirmed to exist. May also be the start date for reporting purposes.attr_FireMgmtComplexityThe highest management level utilized to manage a wildland fire event. attr_FireOutDateTimeThe date and time when a fire is declared out. attr_FireStrategyConfinePercentIndicates the percentage of the incident area where the fire suppression strategy of "Confine" is being implemented.attr_FireStrategyFullSuppPrcntIndicates the percentage of the incident area where the fire suppression strategy of "Full Suppression" is being implemented.attr_FireStrategyMonitorPercentIndicates the percentage of the incident area where the fire suppression strategy of "Monitor" is being implemented.attr_FireStrategyPointZonePrcntIndicates the percentage of the incident area where the fire suppression strategy of "Point Zone Protection" is being implemented.attr_FSJobCodeA code use to indicate the Forest Service job accounting code for the incident. This is specific to the Forest Service. Usually displayed as 2 char prefix on FireCode.attr_FSOverrideCodeA code used to indicate the Forest Service override code for the incident. This is specific to the Forest Service. Usually displayed as a 4 char suffix on FireCode. For example, if the FS is assisting DOI, an override of 1502 will be used.attr_GACCA code that identifies one of the wildland fire geographic area coordination center at the point of origin for the incident.A geographic area coordination center is a facility that is used for the coordination of agency or jurisdictional resources in support of one or more incidents within a geographic coordination area.attr_ICS209ReportDateTimeThe date and time of the latest approved ICS-209 report.attr_ICS209RptForTimePeriodFromThe date and time of the beginning of the time period for the current ICS-209 submission.attr_ICS209RptForTimePeriodToThe date and time of the end of the time period for the current ICS-209 submission. attr_ICS209ReportStatusThe version of the ICS-209 report (initial, update, or final). There should never be more than one initial report, but there can be numerous updates, and even multiple finals (as determined by business rules).attr_IncidentManagementOrgThe incident management organization for the incident, which may be a Type 1, 2, or 3 Incident Management Team (IMT), a Unified Command, a Unified Command with an IMT, National Incident Management Organization (NIMO), etc. This field is null if no team is assigned.attr_IncidentNameThe name assigned to an incident.attr_IncidentShortDescriptionGeneral descriptive location of the incident such as the number of miles from an identifiable town. attr_IncidentTypeCategoryThe Event Category is a sub-group of the Event Kind code and description. The Event Category further breaks down the Event Kind into more specific event categories.attr_IncidentTypeKindA general, high-level code and description of the types of incidents and planned events to which the interagency wildland fire community responds.attr_InitialLatitudeThe latitude location of the initial reported point of origin specified in decimal degrees.attr_InitialLongitudeThe longitude location of the initial reported point of origin specified in decimal degrees.attr_InitialResponseAcresAn estimate of acres burning at the time of initial response. More specifically when the IC arrives and performs initial size up. The minimum size must be 0.1. The estimate should include number of acres within the current perimeter of a specific, individual incident, including unburned and unburnable islands.attr_InitialResponseDateTimeThe date/time of the initial response to the incident. More specifically when the IC arrives and performs initial size up. attr_IrwinIDUnique identifier assigned to each incident record in IRWIN.attr_IsFireCauseInvestigatedIndicates if an investigation is underway or was completed to determine the cause of a fire.attr_IsFSAssistedIndicates if the Forest Service provided assistance on an incident outside their jurisdiction.attr_IsMultiJurisdictionalIndicates if the

This metric represents cost of potential treatments for the Northern California region and is dependent on predefined treatments or silvicultural prescriptions, which are best generated at the local and/or project level. The cost to perform each treatment depends on a defined prescription and should consider an array of factors including the spatial juxtaposition of the resources and infrastructure, as well as the location of the saw timber and biomass processing plants.

Treatment cost calculations take into consideration the multiple costs necessary to move material from the forest harvest site to a processing location (sawmill or biomass facility) and includes the costs of felling, processing, skidding and hauling:

• costs to move material along different types of roads (i.e., dirt, paved, highways, etc.)

• across barriers (i.e., water courses)

• operational costs

• machine costs

• speed of moving material across the landscape.

Cost values have been broken down into the costs to move either biomass or sawlogs, and for a high-cost and low-cost scenario (reflecting variation in machine rates). Non-mechanical hand treatments, piling and burning operations, and prescribed fire treatments are not addressed in this data set. We hope to provide cost estimates on those types of treatments later.

Oregon saw the largest area burned by wildfires across the United States in 2024. That year, about 2,232 individual wildfires burned in the northwestern state, ravishing almost 1.89 million acres. Texas followed second, with roughly 1.3 million acres burned due to wildfires that year. Fire season 2021 and California’s wildfire suppression costs As one of the most wildfire-prone states in the country, California spends a significant amount of money on their suppression. Estimates suggest wildfire suppression expenditure in California climbed to 1.2 billion U.S. dollars in the fiscal year ending June 2022. The fiscal year, which includes the summer and fall months of 2021, was among the most devastating fire seasons on record, with that year’s Dixie fire becoming the second-largest California wildfire by acres burned. The Dixie fire was responsible for over 963,000 acres burned across the state that year. Wildfire causes Wildfires are uncontrolled fires burning across any type of combustible vegetation such as grass- and brushland, forests, and agricultural fields. They are also referred to as wildland fires, forest fires, or bushfires, with the latter term particularly common in Australia. Wildfires regularly occur on all continents of the world, except for Antarctica, but are particularly common in dry regions with dense vegetation. As the rise in average global temperatures is changing weather patterns and resulting in more and more countries being affected by dry, hot weather conditions, the severity and rapid spread of wildfires have increased in recent years. The most common causes of wildfires are natural phenomena such as lightning strikes as well as human activity. The area burned due to human-caused wildfires in the U.S. surpassed 1.5 million acres in 2023.

Link to the ScienceBase Item Summary page for the item described by this metadata record. Service Protocol: Link to the ScienceBase Item Summary page for the item described by this metadata record. Application Profile: Web Browser. Link Function: information

This publication contains tabular data used to evaluate the effects of fuel treatments and previously burned areas on daily wildland fire management costs. The data represent daily Forest Service fire management costs for a sample of 56 fires that burned between 2008 and 2012 throughout the conterminous United States. Included in the data is a suite of spatially derived variables used to control for variation in daily fire management costs, including topography, fire weather, fuel loading, remoteness, and human populations-at-risk. These data were extracted using daily fire progression maps produced using the methods outlined in Parks (2014).

The Wildland Fire Interagency Geospatial Services (WFIGS) Group provides authoritative geospatial data products under the interagency Wildland Fire Data Program. Hosted in the National Interagency Fire Center ArcGIS Online Organization (The NIFC Org), WFIGS provides both internal and public facing data, accessible in a variety of formats.This service includes perimeters for wildland fire incidents that meet the following criteria:Categorized in the IRWIN (Integrated Reporting of Wildland Fire Information) integration service as a valid Wildfire (WF), Prescribed Fire (RX), or Incident Complex (CX) record with a Fire Discovery Date in the year 2021Is not "quarantined" in IRWIN due to potential conflicts with other recordsAttribution of the source polygon is set to a Feature Access of Public, a Feature Status of Approved, and an Is Visible setting of YesPerimeters are not available for every incident. For a complete set of features that meet the same IRWIN criteria, see the 2021 Wildland Fire Locations to Date service.No "fall-off" rules are applied to this service. Criteria were determined by an NWCG Geospatial Subcommittee task group. Data are refreshed every 5 minutes. Changes in the perimeter source may take up to 15 minutes to display.Perimeters are pulled from multiple sources with rules in place to ensure the most current or most authoritative shape is used.Warning: Please refrain from repeatedly querying the service using a relative date range. This includes using the “(not) in the last” operators in a Web Map filter and any reference to CURRENT_TIMESTAMP. This type of query puts undue load on the service and may render it temporarily unavailable.Attributes and their definitions can be found below. More detail about the NWCG Wildland Fire Event Polygon standard can be found here.Attributes:Incident Name (Polygon)The Incident Name from the source polygon.Feature CategoryType of wildland fire perimeter set for the source polygon.Map MethodControlled vocabulary to define how the source polygon was derived. Map Method may help define data quality.GIS AcresUser-calculated acreage on the source polygon.Polygon Create DateSystem field. Time stamp for the source polygon feature creation.Polygon Modified DateSystem field. Time stamp for the most recent edit to the source polygon feature.Polygon Collection Date TimeDate time for the source polygon feature collection.Acres Auto CalculatedAutomated calculation of the source polygon acreage.Polygon SourceData source of the perimeter geometry.{Year} NIFS: Annual National Incident Feature ServiceFFP: Final Fire Perimeter Service (Certified Perimeters)ABCD MiscA FireCode used by USDA FS to track and compile cost information for emergency initial attack fire suppression expenditures. for A, B, C & D size class fires on FS lands.ADS Permission StateIndicates the permission hierarchy that is currently being applied when a system utilizes the UpdateIncident operation.IRWIN Archived OnA date set by IRWIN that indicates when an incident's data has met the rules defined for the record to become part of the historical fire records rather than an operational incident record. The value will be set the current date/time if any of the following criteria are met: 1. ContainmentDataTime or ControlDateTime or FireOutDateTime or ModifiedOnDateTime > 12 months from the current DateTime2. FinalFireReportDate is not null and ADSPermissionState is 'certified'.Calculated AcresA measure of acres calculated (i.e., infrared) from a geospatial perimeter of a fire. More specifically, the number of acres within the current perimeter of a specific, individual incident, including unburned and unburnable islands. The minimum size must be 0.1.Containment Date TimeThe date and time a wildfire was declared contained. Control Date TimeThe date and time a wildfire was declared under control.Created By SystemArcGIS Server Username of system that created the IRWIN Incident record.IRWIN Created On Date TimeDate/time that the IRWIN Incident record was created.IRWIN Daily AcresA measure of acres reported for a fire. More specifically, the number of acres within the current perimeter of a specific, individual incident, including unburned and unburnable islands. The minimum size must be 0.1.Discovery AcresAn estimate of acres burning upon the discovery of the fire. More specifically when the fire is first reported by the first person that calls in the fire. The estimate should include number of acres within the current perimeter of a specific, individual incident, including unburned and unburnable islands.Dispatch Center IDA unique identifier for a dispatch center responsible for supporting the incident.Final Fire Report Approved By TitleThe title of the person that approved the final fire report for the incident.Final Fire Report Approved By UnitNWCG Unit ID associated with the individual who approved the final report for the incident.Final Fire Report Approved DateThe date that the final fire report was approved for the incident.Fire Behavior GeneralA general category describing the manner in which the fire is currently reacting to the influences of fuel, weather, and topography. Fire Behavior General 1A more specific category further describing the general fire behavior (manner in which the fire is currently reacting to the influences of fuel, weather, and topography). Fire Behavior General 2A more specific category further describing the general fire behavior (manner in which the fire is currently reacting to the influences of fuel, weather, and topography). Fire Behavior General 3A more specific category further describing the general fire behavior (manner in which the fire is currently reacting to the influences of fuel, weather, and topography). Fire CauseBroad classification of the reason the fire occurred identified as human, natural or unknown. Fire Cause GeneralAgency or circumstance which started a fire or set the stage for its occurrence; source of a fire's ignition. For statistical purposes, fire causes are further broken into specific causes. Fire Cause SpecificA further categorization of each General Fire Cause to indicate more specifically the agency or circumstance which started a fire or set the stage for its occurrence; source of a fire's ignition. Fire CodeA code used within the interagency wildland fire community to track and compile cost information for emergency fire suppression expenditures for the incident. Fire Department IDThe U.S. Fire Administration (USFA) has created a national database of Fire Departments. Most Fire Departments do not have an NWCG Unit ID and so it is the intent of the IRWIN team to create a new field that includes this data element to assist the National Association of State Foresters (NASF) with data collection.Fire Discovery Date TimeThe date and time a fire was reported as discovered or confirmed to exist. May also be the start date for reporting purposes.Fire Mgmt ComplexityThe highest management level utilized to manage a wildland fire event. Fire Out Date TimeThe date and time when a fire is declared out. Fire Strategy Confine PercentIndicates the percentage of the incident area where the fire suppression strategy of "Confine" is being implemented.Fire Strategy Full Supp PercentIndicates the percentage of the incident area where the fire suppression strategy of "Full Suppression" is being implemented.Fire Strategy Monitor PercentIndicates the percentage of the incident area where the fire suppression strategy of "Monitor" is being implemented.Fire Strategy Point Zone PercentIndicates the percentage of the incident area where the fire suppression strategy of "Point Zone Protection" is being implemented.FS Job CodeA code use to indicate the Forest Service job accounting code for the incident. This is specific to the Forest Service. Usually displayed as 2 char prefix on FireCode.FS Override CodeA code used to indicate the Forest Service override code for the incident. This is specific to the Forest Service. Usually displayed as a 4 char suffix on FireCode. For example, if the FS is assisting DOI, an override of 1502 will be used.GACCA code that identifies one of the wildland fire geographic area coordination center at the point of origin for the incident.A geographic area coordination center is a facility that is used for the coordination of agency or jurisdictional resources in support of one or more incidents within a geographic coordination area.ICS 209 Report Date TimeThe date and time of the latest approved ICS-209 report.ICS 209 Report For Time Period FromThe date and time of the beginning of the time period for the current ICS-209 submission.ICS 209 Report For Time Period ToThe date and time of the end of the time period for the current ICS-209 submission. ICS 209 Report StatusThe version of the ICS-209 report (initial, update, or final). There should never be more than one initial report, but there can be numerous updates, and even multiple finals (as determined by business rules).Incident Management OrganizationThe incident management organization for the incident, which may be a Type 1, 2, or 3 Incident Management Team (IMT), a Unified Command, a Unified Command with an IMT, National Incident Management Organization (NIMO), etc. This field is null if no team is assigned.Incident NameThe name assigned to an incident.Incident Short DescriptionGeneral descriptive location of the incident such as the number of miles from an identifiable town. Incident Type CategoryThe Event Category is a sub-group of the Event Kind code and description. The Event Category further breaks down the Event Kind into more specific event categories.Incident Type KindA general, high-level code and description of the types of incidents and planned events to which the interagency wildland fire community responds.Initial LatitudeThe latitude location of the initial reported point of origin specified in decimal degrees.Initial LongitudeThe longitude location

Wildfires and droughts in California in 2020 resulted in economic costs of between ** and ** billion U.S. dollars. This is far more than in any other U.S. state. Drought-conditions have worsened in the U.S. Southwest over the last few years, with Nevada the only Southwest state not yet having declared a drought-related state of emergency.

The following datasets are included in this record. Directories are contained with .tar files of the same name. Sources in parentheses (may be outdated).

• CA-HPI.csv: Home price index data for California (https://fred.stlouisfed.org/series/CASTHPI)
• ca_places/: CA Geographic Boundaries (https://data.ca.gov/dataset/ca-geographic-boundaries)
• CensusTiger/: Census TIGER Shapefiles (https://www.census.gov/geographies/mapping-files/time-series/geo/tiger-line-file.html)
• DamageData/: Post-fire damage data from CAL FIRE DINS (https://data.ca.gov/dataset/cal-fire-damage-inspection-dins-data) and other sources (various)
• FirePerimeters/: Fire perimeter data from FRAP(https://www.fire.ca.gov/what-we-do/fire-resource-assessment-program), NIFC (https://www.nifc.gov/fire-information/maps), MTBS (https://www.mtbs.gov/direct-download), and other sources (various)
• HAZUS/: FEMA HAZUS data on rebuilding costs by Census block (https://www.fema.gov/flood-maps/products-tools/hazus)
• LANDFIRE/: LANDFIRE data on aspect, elevation, slope, and Anderson 13 fuel model (https://www.landfire.gov/)
• NolteEtAl/: Appendix Tables from Nolte et al. 2024 (https://le.uwpress.org/content/100/1/200.abstract)
• simplemaps_uscities_basicv1.72/: Simplemaps US Cities Database (https://simplemaps.com/data/us-cities)
• SRAandFHSZ: Collection of SRA and FHSZ shapefiles to identify homes in building code areas (CAL FIRE)

This metric represents cost of potential treatments for the Northern California region and is dependent on predefined treatments or silvicultural prescriptions, which are best generated at the local and/or project level. The cost to perform each treatment depends on a defined prescription and should consider an array of factors including the spatial juxtaposition of the resources and infrastructure, as well as the location of the saw timber and biomass processing plants.

Treatment cost calculations take into consideration the multiple costs necessary to move material from the forest harvest site to a processing location (sawmill or biomass facility) and includes the costs of felling, processing, skidding and hauling:

• costs to move material along different types of roads (i.e., dirt, paved, highways, etc.)

• across barriers (i.e., water courses)

• operational costs

• machine costs

• speed of moving material across the landscape.

Cost values have been broken down into the costs to move either biomass or sawlogs, and for a high-cost and low-cost scenario (reflecting variation in machine rates). Non-mechanical hand treatments, piling and burning operations, and prescribed fire treatments are not addressed in this data set. We hope to provide cost estimates on those types of treatments later.

Across the Western United States, human development into the wildland urban interface (WUI) is contributing to increasing wildfire damage. Given that natural disasters often cause greater harm within socio-economically vulnerable groups, research is needed to explore the potential for disproportionate impacts associated with wildfire. Using Zillow Transaction and Assessment Database (ZTRAX), hereafter “Zillow”, real estate data, we explored whether lower-priced structures were more likely to be damaged during the most destructive, recent wildfires in Southern California. Within fire perimeters occurring from 2000–2019, we matched property price data to burned and unburned structures. To be included in the final dataset, fire perimeters had to surround at least 25 burned and 25 unburned structures and have been sold at most seven years before the fire; five fires fit these criteria. We found evidence to support our hypothesis that lower-priced properties were more likely to be damaged, however, the likelihood of damage and the influence of property value significantly varied across individual fire perimeters. When considering fires individually, properties within two 2003 fires–the Cedar and Grand Prix-Old Fires–had statistically significantly decreasing burn damage with increasing property value. Occurring in 2007 and later, the other three fires (Witch-Poomacha, Thomas, and Woolsey) showed no significant relationship between price and damage. Consistent with other studies, topographic position, slope, elevation, and vegetation were also significantly associated with the likelihood of a structure being damaged during the wildfire. Driving time to the nearest fire station and previously identified fire hazard were also significant. Our results suggest that further studies on the extent and reason for disproportionate impacts of wildfire are needed. In the meantime, decision makers should consider allocating wildfire risk mitigation resources–such as fire-fighting and wildfire structural preparedness resources–to more socioeconomically vulnerable neighborhoods.

This metric represents cost of potential treatments for the Northern California region and is dependent on predefined treatments or silvicultural prescriptions, which are best generated at the local and/or project level. The cost to perform each treatment depends on a defined prescription and should consider an array of factors including the spatial juxtaposition of the resources and infrastructure, as well as the location of the saw timber and biomass processing plants.

Treatment cost calculations take into consideration the multiple costs necessary to move material from the forest harvest site to a processing location (sawmill or biomass facility) and includes the costs of felling, processing, skidding and hauling:

• costs to move material along different types of roads (i.e., dirt, paved, highways, etc.)

• across barriers (i.e., water courses)

• operational costs

• machine costs

• speed of moving material across the landscape.

Cost values have been broken down into the costs to move either biomass or sawlogs, and for a high-cost and low-cost scenario (reflecting variation in machine rates). Non-mechanical hand treatments, piling and burning operations, and prescribed fire treatments are not addressed in this data set. We hope to provide cost estimates on those types of treatments later.

This metric represents cost of potential treatments for the Northern California region and is dependent on predefined treatments or silvicultural prescriptions, which are best generated at the local and/or project level. The cost to perform each treatment depends on a defined prescription and should consider an array of factors including the spatial juxtaposition of the resources and infrastructure, as well as the location of the saw timber and biomass processing plants.

Treatment cost calculations take into consideration the multiple costs necessary to move material from the forest harvest site to a processing location (sawmill or biomass facility) and includes the costs of felling, processing, skidding and hauling:

• costs to move material along different types of roads (i.e., dirt, paved, highways, etc.)

• across barriers (i.e., water courses)

• operational costs

• machine costs

• speed of moving material across the landscape.

Cost values have been broken down into the costs to move either biomass or sawlogs, and for a high-cost and low-cost scenario (reflecting variation in machine rates). Non-mechanical hand treatments, piling and burning operations, and prescribed fire treatments are not addressed in this data set. We hope to provide cost estimates on those types of treatments later.

Higuera, P.E., M.C. Cook, J.K. Balch, E.N. Stavros, A.L. Mahood, and L.A. St. Denis. 2023. Shifting social-ecological fire regimes explain increasing structure loss from Western wildfires. PNAS Nexus 2: In Press. Structure loss is an acute, costly impact of the wildfire crisis in the western United States (“West”), motivating the need to understand recent trends and causes. We document a 246% rise in West-wide structure loss from wildfires between 1999–2009 and 2010–2020, driven strongly by events in 2017, 2018, and 2020. Increased structure loss was not due to increased area burned alone. Wildfires became significantly more destructive, with a 160% higher structure loss rate (loss/kha burned) over the past decade. Structure loss was driven primarily by wildfires from unplanned human-related ignitions (e.g. backyard burning, power lines, etc.), which accounted for 76% of all structure loss and resulted in 10 times more structures destroyed per unit area burned compared to lightning-ignited fires. Annual structure loss was well explained by area burned from human-related ignitions, while decadal structure loss was explained by state-level structure abundance in flammable vegetation. Both predictors increased over recent decades and likely interacted with increased fuel aridity to drive structure-loss trends. While states are diverse in patterns and trends, nearly all experienced more burning from human-related ignitions and/or higher structure loss rates, particularly California, Washington, and Oregon. Our findings highlight how fire regimes – characteristics of fire over space and time – are fundamentally social-ecological phenomena. By resolving the diversity of Western fire regimes, our work informs regionally appropriate mitigation and adaptation strategies. With millions of structures with high fire risk, reducing human-related ignitions and rethinking how we build are critical for preventing future wildfire disasters. Methods See associated paper.

The foundation of quantitative wildfire hazard or risk assessment is a current-condition fuelscape (i.e., fuel and terrain layers), ideally updated to account for recent disturbances and calibrated to reflect the fire behavior potential observed in recent historical wildfire events. This data publication provides the fuelscape generated for a wildfire risk assessment focused on the sagebrush biome of the western United States (US). The data depict ca. 2020 fuel conditions, after customization, to better reflect expected fire behavior in sagebrush ecosystems, including influences from exotic annual grass (e.g., cheatgrass) invasion and conifer (e.g., pinyon, juniper) encroachment. These data are presented as used for biome-wide geospatial fire modeling at a 270-meter resolution. The work was conducted using simulation units called “pyromes,” which represent areas of relatively homogenous contemporary fire regimes. The sagebrush biome is represented by 31 pyromes, covering about 450 million acres in total area. Fuelscapes for the 31 pyromes are included in this data product as separate multiband GeoTIFFs. The bands of each GeoTIFF store eight layers of data that describe terrain (aspect, elevation, slope), tree canopy (cover, height, base height, bulk density), and surface fuel (FBFM40). These data form the Landscape (LCP) file commonly used by US wildland fire behavior modeling systems (e.g., FlamMap, FSPro, FSim). Each fuelscape dataset includes a 30-kilometer buffer to avoid truncating the simulated fires at pyrome boundaries. A shapefile and geopackage containing the boundaries and size of each pyrome are also included.In the western United States, hundreds of thousands of acres of highly imperiled sagebrush ecosystems are lost or degraded each year as a result of altered wildfire regimes. In response to these wildfire threats, extensive fuel treatment investments have been proposed throughout the region. Regional-scale assessment of wildfire risk offers a consistent means of evaluating threats to valued resources and assets, thereby facilitating the most cost-effective investments in management activities that can mitigate those risks. We used a large-fire simulation system (FSim) to estimate the probabilistic components of wildfire risk across the sagebrush biome, which includes portions of 13 western states. This publication includes the customized fuelscape data used for that fire-modeling work.

We monitored Greater Sage-Grouse (Centrocercus urophasianus; hereafter, Sage-Grouse) nests and various habitat characteristics at the nest locations near Susanville in northeastern California, crossing over into northwestern Nevada. We employed a before-after-control-impact (BACI) experimental design to account for spatiotemporal heterogeneity in the system and to derive estimates of relative change in survival parameters. Sage-Grouse nest survival decreased after the Rush Fire but decreased more in the burned area relative to the unburned area. Although female Sage-Grouse continued to occupy burned areas, nest survival was reduced from 52 percent to 19 percent. Using a BACI ratio approach we found that nest survival decreased approximately 51 percent in the burned area, relative to the unburned area, following wildfire. Habitat analyses were restricted to the post-fire period and found that female Sage-Grouse that nested within unburned areas selected for wider nesting substrate, taller perennial grass height, and greater low sagebrush canopy cover. Conversely, female Sage-Grouse that nested in burned areas used shorter sagebrush canopy cover than what was available across the entire study area, but showed stronger selection for perennial grass height than their unburned counterparts. Strong nest-site fidelity in sage-grouse may explain the continued use of suboptimal habitat in wildfire-altered landscapes, resulting in a reproductive cost, and overall reproduction well below replacement rate. Results suggest that fire suppression or rapid post-fire habitat restoration, especially within nesting habitat, may be essential to conserving robust Sage-Grouse populations into the future.

Unless otherwise noted, all raster-based maps had a 90-meter resolution.

Demographic data come from CalEnviroScreen 4.0 which summarizes U.S. Census data at the resolution of the census tract. Values in the table are the means ± standard deviations across structures within a given fire perimeter.

The r2s for the Cedar, Grand Prix-Old, Witch-Poomacha, Thomas, and Woolsey fires are 0.14, 0.10, 0.10, 0.13, and 0.20, respectively. TPI refers to the topographic position index within a 500m window.