These two precipitation variables are among several ecological settings variables that collectively characterize the biophysical setting of each 30 m cell at a given point in time (McGarigal et al 2017). The amount of rainfall and depth of snowpack affects species composition, as well as ecological processes such as nutrient cycling. We’ve chosen two variables to represent precipitation. Both variables have future versions that incorporate climate change via General Circulation Models (GCMs) (as described in the technical document on climate, McGarigal et al 2017).
McGarigal, Kevin; Compton, Brad; Plunkett, Ethan; DeLuca, Bill; and Grand, Joanna, "Designing Sustainable Landscapes: Total annual precipitation and growing season precipitation settings variables" (2017). Data and Datasets. 57.