LANDFIRE’s (LF) 2001 Canopy Base Height (CBH) product describes the lowest point in a stand where there is sufficient available fuel (greater than or equal to .25 in diameter) to propagate fire vertically through the canopy. Specifically, CBH is defined as the lowest point at which the canopy bulk density is greater than or equal to 0.012 kg m3. A spatially explicit map of canopy base height supplies information used in fire behavior models such as FARSITE (Finney 1998) to determine the point at which a surface fire will transition to a crown fire. The CBH mapping process began by deriving field referenced estimates of canopy characteristics through LFRDB plot analysis. Approximately 50,000 plots were acquired throughout the U.S. for estimating CBH in LF 2001. Utilizing these plots, field referenced CBH values were calculated for each plot using the canopy fuel estimation software FuelCalc. Using the information gleaned from the statistical analysis it was decided to map CBH values using an average Look Up Table (LUT) approach based on plot level combinations of Existing Vegetation Height (EVH), Cover (EVC), and Type (EVT). To assign averages using these variables, various grouping combinations of EVT, EVC, and EVH were tested to determine which would map CBH values most logically. For each grouping, a set of LUTs were calculated enabling CBH to be mapped with the Fuels Change Mapping Tool, or ToFu Delta. These maps were analyzed, peer reviewed and tested to determine which performed best. The CBH data represented in the resultant layer are continuous from 0 to 9.9 meters (to the nearest 0.1 meter). Some stands dominated by broadleaf species which typically do not permit initiation of crown fire (e.g. Populus spp.) are coded with a CBH of 10 meters. Since crown fire is rarely observed in most hardwood stands, the highest CBH value possible was used to prevent false simulation of crown fire in these areas. Similarly, all non-forest values, including herbaceous, and shrub systems and non-burnable types such as urban, barren, snow and ice and agriculture, were coded as 0. Finally, certain types of agriculture that are deemed burnable were assigned a value by ToFuDelta based on region and vegetation type.

LANDFIRE's 2023 Update (LF 2023) Forest Canopy Height (CH) describes the average height of the top of the canopy for a stand. CH is used in the calculation of Forest Canopy Bulk Density (CBD) and Base Height (CBH). CH supplies information for fire behavior models, such as FARSITE (Finney 1998), that can determine the starting point of embers in the spotting model, wind reductions, and the volume of crown fuels. To create CH, LANDFIRE's Existing Vegetation Height (EVH) product must be produced first. EVH is a continuous scaled product which assigns height to all life forms in the LF data. CH is then derived from EVH by assigning bins of 13 height classes for fuel production and use in fire behavior software. In LF 2023, fuel products are created with LF 2016 Remap vegetation in areas that were un-disturbed in the last twenty years. To designate disturbed areas where CH is modified, the aggregated Annual Disturbance products from 2014 to 2023 in the LF Fuel Disturbance (FDist) product are used. All existing disturbances between 2014-2023 are represented in LF 2023, and the products are intended to be used in 2024 (the year of release). When using any product from the LF 2023 fuel product suite, users should consider adjusting fuel layers for disturbances that occurred after the end of the 2023 fiscal year (after October 1st, 2023). Disturbances that occurred after the end of the 2023 fiscal year are not accounted for within LF 2023 fuel products. Learn more about LF 2023 at https://landfire.gov/data/lf2023.

LANDFIRE's 2023 Update (LF 2023) Forest Canopy Height (CH) describes the average height of the top of the canopy for a stand. CH is used in the calculation of Forest Canopy Bulk Density (CBD) and Base Height (CBH). CH supplies information for fire behavior models, such as FARSITE (Finney 1998), that can determine the starting point of embers in the spotting model, wind reductions, and the volume of crown fuels. To create CH, LANDFIRE's Existing Vegetation Height (EVH) product must be produced first. EVH is a continuous scaled product which assigns height to all life forms in the LF data. CH is then derived from EVH by assigning bins of 13 height classes for fuel production and use in fire behavior software. In LF 2023, fuel products are created with LF 2016 Remap vegetation in areas that were un-disturbed in the last twenty years. To designate disturbed areas where CH is modified, the aggregated Annual Disturbance products from 2014 to 2023 in the LF Fuel Disturbance (FDist) product are used. All existing disturbances between 2014-2023 are represented in LF 2023, and the products are intended to be used in 2024 (the year of release). When using any product from the LF 2023 fuel product suite, users should consider adjusting fuel layers for disturbances that occurred after the end of the 2023 fiscal year (after October 1st, 2023). Disturbances that occurred after the end of the 2023 fiscal year are not accounted for within LF 2023 fuel products. Learn more about LF 2023 at https://landfire.gov/data/lf2023.

LANDFIRE's (LF) 2022 Forest Canopy Height (CH) describes the average height of the top of the canopy for a stand. CH is used in the calculation of Canopy Bulk Density (CBD) and Canopy Base Height (CBH). CH supplies information for fire behavior models, such as FARSITE (Finney 1998), that can determine the starting point of embers in the spotting model, wind reductions, and the volume of crown fuels. To create this product, plot level CH values are calculated using the canopy fuel estimation software, Forest Vegetation Simulator (FVS). Pre-disturbance Canopy Cover and CH are used as predictors of disturbed CH using a linear regression equation per Fuel Vegetation Type (FVT), disturbance type/severity, and time since disturbance. CH is used in the calculation of Canopy Bulk Density (CBD) and Canopy Base Height (CBH). In LF 2022, fuel products are created with LF 2016 Remap vegetation in areas that were un-disturbed in the last ten years. To designate disturbed areas where CH is modified, the aggregated Annual Disturbance products from 2013 to 2022 in the Fuel Disturbance (FDist) product are used. All existing disturbances between 2013-2022 are represented in the LF 2022 update, and the products are intended to be used in 2023 (the year of release). The "capable" year terminology used in LF 2020 and LF 2016 Remap is no longer specified, due to reduction in latency from when a disturbance occurs to the release date of fuel products accounting for that disturbance. However, users should still consider adjusting fuel layers for disturbances that occurred after the end of the 2022 fiscal year (after October 1st, 2022) when using the LF 2022 fuel products. Because those changes would not be accounted for. Learn more about LF 2022 at https://landfire.gov/lf_230.php

LANDFIRE's (LF) 2022 Forest Canopy Height (CH) describes the average height of the top of the canopy for a stand. CH is used in the calculation of Canopy Bulk Density (CBD) and Canopy Base Height (CBH). CH supplies information for fire behavior models, such as FARSITE (Finney 1998), that can determine the starting point of embers in the spotting model, wind reductions, and the volume of crown fuels. To create this product, plot level CH values are calculated using the canopy fuel estimation software, Forest Vegetation Simulator (FVS). Pre-disturbance Canopy Cover and CH are used as predictors of disturbed CH using a linear regression equation per Fuel Vegetation Type (FVT), disturbance type/severity, and time since disturbance. CH is used in the calculation of Canopy Bulk Density (CBD) and Canopy Base Height (CBH). In LF 2022, fuel products are created with LF 2016 Remap vegetation in areas that were un-disturbed in the last ten years. To designate disturbed areas where CH is modified, the aggregated Annual Disturbance products from 2013 to 2022 in the Fuel Disturbance (FDist) product are used. All existing disturbances between 2013-2022 are represented in the LF 2022 update, and the products are intended to be used in 2023 (the year of release). The "capable" year terminology used in LF 2020 and LF 2016 Remap is no longer specified, due to reduction in latency from when a disturbance occurs to the release date of fuel products accounting for that disturbance. However, users should still consider adjusting fuel layers for disturbances that occurred after the end of the 2022 fiscal year (after October 1st, 2022) when using the LF 2022 fuel products. Because those changes would not be accounted for. Learn more about LF 2022 at https://landfire.gov/lf_230.php

LANFIRE’s (LF) 2016 Remap (Remap) Forest Canopy Height (CH) describes the average height of the top of the canopy for a stand. In disturbed locations CH is calculated from linear regression equations derived from Forest Vegetation Simulator (FVS) plot data output, but at non-disturbed locations it is assigned the midpoint of Fuel Vegetation Height (FVH) forested classes. In some instances, LF Remap assumes the potential burnable biomass in the tree canopy has been accounted for in the surface fuel model. For example, young or short conifer stands where the trees are represented by a shrub type fuel model will not have canopy characteristics. LF Remap Annual Disturbance products are incorporated into CH to provide informed changes by disturbance type, severity, and time since disturbance (TSD). Annual Disturbance products provide a pre-disturbance scenario represented by LF Remap existing vegetation products, the reporting of pre-disturbance scenarios helps to calculate CH. Vegetation adjustments are then modeled in disturbance areas based on disturbance type and severity. CH is then used in the calculation of Canopy Bulk Density (CBD) and Canopy Base Height (CBH). CH supplies information for fire behavior models, such as FARSITE (Finney 1998), that can determine; the starting point for embers in the spotting model, wind reductions, and the volume of crown fuels. CH also has capable fuels functionality, capable fuels calculate TSD assignments for disturbed areas using an "effective year." For example, year 2020 fuels may be calculated for the year 2020. the new process considers all the existing disturbances included in LF Remap and adjusts the TSD for these to the effective year (2020 in the example), making the products "2020 capable fuels." More information about capable fuels can be found at https://www.landfire.gov/lf_remap.php.

LANFIRE’s (LF) 2016 Remap (Remap) Forest Canopy Height (CH) describes the average height of the top of the canopy for a stand. In disturbed locations CH is calculated from linear regression equations derived from Forest Vegetation Simulator (FVS) plot data output, but at non-disturbed locations it is assigned the midpoint of Fuel Vegetation Height (FVH) forested classes. In some instances, LF Remap assumes the potential burnable biomass in the tree canopy has been accounted for in the surface fuel model. For example, young or short conifer stands where the trees are represented by a shrub type fuel model will not have canopy characteristics. LF Remap Annual Disturbance products are incorporated into CH to provide informed changes by disturbance type, severity, and time since disturbance (TSD). Annual Disturbance products provide a pre-disturbance scenario represented by LF Remap existing vegetation products, the reporting of pre-disturbance scenarios helps to calculate CH. Vegetation adjustments are then modeled in disturbance areas based on disturbance type and severity. CH is then used in the calculation of Canopy Bulk Density (CBD) and Canopy Base Height (CBH). CH supplies information for fire behavior models, such as FARSITE (Finney 1998), that can determine; the starting point for embers in the spotting model, wind reductions, and the volume of crown fuels. CH also has capable fuels functionality, capable fuels calculate TSD assignments for disturbed areas using an "effective year." For example, year 2020 fuels may be calculated for the year 2020. the new process considers all the existing disturbances included in LF Remap and adjusts the TSD for these to the effective year (2020 in the example), making the products "2020 capable fuels." More information about capable fuels can be found at https://www.landfire.gov/lf_remap.php.

LANDFIRE's 2023 Update (LF 2023) Forest Canopy Base Height (CBH) supplies information used in fire behavior models to determine the critical point at which a surface fire will transition to a crown fire in conjunction with other environmental factors (such as wind speed and moisture content). CBH data is continuous from 0 to 9.9 meters (to the nearest 0.1m) and describe the lowest point in a stand where there is enough available fuel (0.25in diameter) to propagate fire vertically through the canopy. Critical CBH is defined as the lowest point at which the Forest Canopy Bulk Density (CBD) is .012kg m-3. Under different scenarios of disturbance and based on previous research incorporating plot-level CBH calculations, CBH for disturbed areas is determined via a set of linear equations relating Forest Canopy Height (CH) and Cover (CC) to CBH. Linear equations for these calculations are derived from Forest Vegetation Simulator (FVS) scenario outputs. To designate disturbed areas where CBH is modified, the aggregated Annual Disturbance products from 2014 to 2023 in the LF Fuel Disturbance (FDist) product are used. All existing disturbances between 2014-2023 are represented in LF 2023, and the products are intended to be used in 2024 (the year of release). When using any product from the LF 2023 fuel product suite, users should consider adjusting fuel layers for disturbances that occurred after the end of the 2023 fiscal year (after October 1st, 2023). Disturbances that occurred after the end of the 2023 fiscal year are not accounted for within LF 2023 fuel products. Learn more about LF 2023 at https://landfire.gov/data/lf2023

LANDFIRE's 2023 Update (LF 2023) Forest Canopy Base Height (CBH) supplies information used in fire behavior models to determine the critical point at which a surface fire will transition to a crown fire in conjunction with other environmental factors (such as wind speed and moisture content). CBH data is continuous from 0 to 9.9 meters (to the nearest 0.1m) and describe the lowest point in a stand where there is enough available fuel (0.25in diameter) to propagate fire vertically through the canopy. Critical CBH is defined as the lowest point at which the Forest Canopy Bulk Density (CBD) is .012kg m-3. Under different scenarios of disturbance and based on previous research incorporating plot-level CBH calculations, CBH for disturbed areas is determined via a set of linear equations relating Forest Canopy Height (CH) and Cover (CC) to CBH. Linear equations for these calculations are derived from Forest Vegetation Simulator (FVS) scenario outputs. To designate disturbed areas where CBH is modified, the aggregated Annual Disturbance products from 2014 to 2023 in the LF Fuel Disturbance (FDist) product are used. All existing disturbances between 2014-2023 are represented in LF 2023, and the products are intended to be used in 2024 (the year of release). When using any product from the LF 2023 fuel product suite, users should consider adjusting fuel layers for disturbances that occurred after the end of the 2023 fiscal year (after October 1st, 2023). Disturbances that occurred after the end of the 2023 fiscal year are not accounted for within LF 2023 fuel products. Learn more about LF 2023 at https://landfire.gov/data/lf2023

LANFIRE’s (LF) Remap Forest Canopy Height (CH) describes the average height of the top of the canopy for a stand. In disturbed locations CH is calculated from linear regression equations derived from Forest Vegetation Simulator (FVS) plot data output, but at non-disturbed locations it is assigned the midpoint of Fuel Vegetation Height (FVH) forested classes. In some instances, LF Remap assumes the potential burnable biomass in the tree canopy has been accounted for in the surface fuel model. For example, young or short conifer stands where the trees are represented by a shrub type fuel model will not have canopy characteristics. LF Remap Annual Disturbance products are incorporated into CH to provide informed changes by disturbance type, severity, and time since disturbance (TSD). Annual Disturbance products provide a pre-disturbance scenario represented by LF Remap existing vegetation products, the reporting of pre-disturbance scenarios helps to calculate CH. Vegetation adjustments are then modeled in disturbance areas based on disturbance type and severity. CH is then used in the calculation of Canopy Bulk Density (CBD) and Canopy Base Height (CBH). CH supplies information for fire behavior models, such as FARSITE (Finney 1998), that can determine; the starting point for embers in the spotting model, wind reductions, and the volume of crown fuels. CH also has capable fuels functionality, capable fuels calculate TSD assignments for disturbed areas using an “effective year.” For example, year 2020 fuels may be calculated for the year 2020. This new process considers all the existing disturbances included in LF Remap and adjusts the TSD for these to the effective year (2020 in this example), making the products "2020 capable fuels." More information about capable fuels can be found at https://www.landfire.gov/lf_remap.php.