Standing Dead and Ladder Fuels

This is the material that may burn at the extreme end of the spectrum and contribute to mass fire behavior (Stephens et al., 2022), especially during crown spread type events. Live "ladder" fuels for trees less than 10" in diameter are also included in this calculation.

Data and Resources

Additional Info

Field Value
Last Updated January 17, 2025, 06:42 (UTC)
Created January 17, 2025, 06:42 (UTC)
category /Fire Dynamics/Severity
collection_name California Landscape Metrics
creation_method This data layer currently exists only for the Sierra Nevada region. Efforts are underway to explore development of F3 data for the rest of California. The [F3 model](https://docs.google.com/document/d/15tXCMkEzUEgQKHoXL74cftwtLuz3z-Rm/edit#heading=h.1t3h5sf) generated raster surfaces to estimate the small size live trees (those <10" DBH) branchwood and foliage plus unmerchantable portions of stemwood above 4-inch diameter (BMCWN_x) as ladder fuels. The model also generated the standing dead estimates for all size classes (including stems, branches, and foliage still present) from the FVS Fire and Fuels extension carbon report (Standing_D). 2019 to 2021 Update: Values for 2021 were adjusted using the Ecosystem Disturbance and Recovery Tracker (eDaRT), described in the [Introduction](https://docs.google.com/document/d/15tXCMkEzUEgQKHoXL74cftwtLuz3z-Rm/edit#heading=h.2s8eyo1). All eDaRT events beginning August 1, 2019 through November 30, 2021 were identified, and the corresponding Mortality Magnitude Index (MMI) values for these events was summed, giving the estimated fractional canopy cover loss per 30m pixel over that time period. The MMI value for canopy cover loss was used as a direct proxy to estimate biomass loss, following the formula: _2021 BMCWN_x = 2019 BMCWN_x '€“ (2019 BMCWN_x * MMI/100)_ Although the assumption of direct correlation between canopy cover and biomass should be viewed with caution, it serves as a reasonable approximation for representative mixed conifer forests in the Sierra Nevada affected by the recent drought (Slaton et al. 2022). The assumption that canopy cover loss, as estimated using eDaRT MMI, was equitably distributed among predefined size classes may result in over- or under-estimates of actual small size trees, depending on location. Adjustments for the standing dead trees raster (Standing_D) took the difference between 2019 and 2021 live volume (as estimated using eDaRT MMI) converted to short tons/acre using a conversion factor of 32.1 cubic feet/ton and the result was summed with 2019 standing dead. This adjusted value was then added to the non-overlapping, predefined size classes for the small size live trees (<10" DBH) branchwood and foliage plus unmerchantable portions of stemwood above 4-inch diameter (BMCWN_x), which had been adjusted for 2021 using MMI percent adjustments. This layer for the Standing Dead and Ladder Fuels metric is derived from F3 layers (2021) using the following formula: _sum(Standing_D, BMCWN_0, BMCWN_2, BMCWN_7)_
data_resolution 30m Raster
data_units Short tons/acre
data_vintage 2021
encoding utf8
file_name SNV_StndDeadLadderFuels_202111_202209_T2_v5
format GeoTiff
harvest_object_id ec67f99d-11e8-4102-b718-667d989e6cb4
harvest_source_id a2637971-af12-457f-ae4a-831d2202a539
harvest_source_title WIFIRE Commons
maximum_value 210.3
metric_definition_and_relevance This is the material that may burn at the extreme end of the spectrum and contribute to mass fire behavior (Stephens et al., 2022), especially during crown spread type events. Live "ladder" fuels for trees less than 10" in diameter are also included in this calculation.
minimum_value 0.0
spatial {"type": "Polygon", "coordinates": [[[-122.2883616476824, 35.05769372687348], [-117.5563290826801, 35.05769372687348], [-117.5563290826801, 42.00332292672577], [-122.2883616476824, 42.00332292672577], [-122.2883616476824, 35.05769372687348]]]}
tier 2