LANDFIRE's (LF) 2023 update (LF 2023) Existing Vegetation Cover (EVC) represents the vertically projected percent cover of the live canopy for a 30-m cell. EVC is produced separately for tree, shrub, and herbaceous lifeforms. Training data depicting percentages of canopy cover are obtained from plot-level ground-based visual assessments and lidar observations. These are combined with Landsat imagery (from multiple seasons), to inform models built independently for each lifeform. Tree, shrub, and herbaceous lifeforms each have a potential range from 10% to 100% (cover values less than 10% are binned into the 10% value). The three independent lifeform datasets are merged into a single product based on the dominant lifeform of each pixel. The EVC product is then reconciled through QA/QC measures to ensure lifeform is synchronized with Existing Vegetation Height (EVH).
In Alaska, developed and agricultural lands were derived from the National Land Cover Database (NLCD) 2016 Land Cover. Roads were derived from the NLCD 2016 Developed Urban Descriptor for south-central Alaska and a state-wide dataset from HERE Technologies. In the Alaska 90km buffer area developed and agricultural lands were derived from the North American Land Change Monitoring System ((NALCMS) https://www.mrlc.gov/data/north-american-land-change-monitoring-system) 2015 Land Cover and new developed lands were added from the NALCMS 2020 Land Cover for LF 2023.
Disturbance events after 2016 are accounted for by incorporating transition rulesets using LF 2023 Fuel Disturbance (FDist). LF uses EVC as an input for LF 2023 Fuel Vegetation Cover (FVC).