Tree Cover is vital to protecting biodiversity and provides essential ecosystem services that support healthy watersheds. This indicator used thresholds from NOAA (NOAA Guidelines) for the amount of forested area that is needed to protect water quality as guidance for thresholds.
How is it scored?
The percentage of tree cover, also called canopy cover, was used for determining the area of a watershed that was forested. Data were analyzed at the census block scale. The amount of tree cover in a census block was converted to a 0–100 scale using the equation, y = x + 20. Blocks with tree cover that were less than 20% were scored as 0, while those with 80% or more tree cover were scored a 100. The census block score was area-weighted to calculate a watershed score. Watershed scores were area-weighted to calculate an overall regional score.
Data source: https://www.mrlc.gov/data/nlcd-2016-usfs-tree-canopy-cover-conus.