
* Metric Name: Cumulative Shrub Cover Lost  

* Tier: 1  

* Data Vintage: 2021  

* Unit Of Measure: Cumulative fractional non-overlapping absolute shrub cover loss, where shrub cover is a continuous variable from 0 to 1. Cumulative loss can exceed 1 in cases with multiple disturbances.

The cumulative loss of shrub cover over a 30-year period (1992-2021). Shrub
cover loss reflects fires, harvest/management and dieoff. Only disturbances
that are sufficient to trigger the Continuous Change Detection and
Classification algorithm are included; low-level, diffuse dieoff is likely
missed.

* Creation Method: Vegetation disturbances were identified over the Landsat TM/ETM+/OLI era using the Continuous Change Detection and Classification algorithm (CCDC). The corresponding annual change in shrub cover was determined with machine learning (Random Forest) using the National Land Cover Database for training and Landsat/CCDC observations as predictors; this produced a ~35-year stack of rasters that identified the locations and severity of shrub cover loss. This stack was then summed for 1992-2021 to calculate the cumulative tree cover loss over a 30-year period. See https://doi.org/10.1029/2021AV000654 for further information.  

* Credits: CECS; 

