Baldi et al._Opportunities drive the global distribution of protected areas.xlsx

We describe with histograms the distribution of terrestrial protected areas along physical, human, and biological independent gradients. Linear and non-linear regressions and correlations lead to a general description of sign, shape, and strength of the relationships; a random forest analysis leads to an importance ranking of the variables related to individual preferential motivations and opportunistic forces; and an evenness metric seizes the strength of variables related to individual representative motivations.