Climate Moisture Index
A BIOCLIM+ raster map of the continental U.S.A. containing 30-year
climate moisture index averages (1981-2010) was downloaded from the
CHELSA (Climatologies at high resolution for the Earth’s land surface
areas) database (Brun et al., 2022). The climate moisture index is
calculated as the difference between mean annual precipitation and mean
potential evapotranspiration and, when negative, represents the
availability of water as a limiting resource in dry regions such as
prairies.