For selection of nonredundant environmental variables for the
modeling, we calculated Pearson correlation coefficients for all
combinations of the environmental layers and removed single
layers that were highly correlated pairwise (|r|$0.80). Variables
representing extreme environmental conditions were preferably
maintained because they have significant effects on species
[38,39]. The remaining nine environmental layers used for the
modeling were: elevation, mean monthly temperature range,
temperature seasonality, maximum temperature of warmest
month, minimum temperature of coldest month, temperature
annual range, annual precipitation, precipitation of wettest month,
and precipitation of driest month.