Percentage of variability (%var) explained by the variables that are significantly correlated with βSIM or βNES (see Table 1) for the regional cells above (>37th) and below (th) the 37th parallel.

“Complete” is the joint variability accounted for by all of the considered predictors. “Single” is the variability accounted for by a variable or group of variables after the effect of the other considered predictors has been controlled for. “Shared” is the variability that cannot be unequivocally attributed to any one of the predictors. TPRES = Mean annual temperature for the present; TPAST = Mean annual temperature for the LGM period; PET = Current annual potential evapotranspiration; PREC = Current annual precipitation; and ARANGE = Altitudinal variability.