Species richness calculations.
GMBA provides 2.5’ resolution shapefiles delimiting each mountain (e.g., Abajo Peak) and mountain range (e.g., Appalachia or the Andes) in the Americas. To assess diversity metrics, such as species richness, we first parsed the Americas shapefiles into half-degree grid cells (‘sites’) and tabulated which species were predicted to be present within each site (presence required at least a 5% chance of finding the species within at least 25% of the area covered by the grid cell). Total site richness was obtained by summing the number of species predicted for each site (Fig. 2). Expected species lists resulting from this method, cross-referenced by country, were deposited with Dryad (https://doi.org/10.5061/dryad.9cnp5hqgx).