We recorded the number of terrestrial mammal species in each Argentinian
province, and the number of species belonging to particular groups (Marsupialia, Placentaria,
and among the latter, Xenarthra, Carnivora, Ungulates and Rodentia). We
performed multiple regressions of each group’s SR on environmental, human and spatial
variables, to determine the amounts of variation explained by these factors. We then
used a variance partitioning procedure to specify which proportion of the variation in SR
is explained by each of the three factors exclusively and which proportions are attributable
to interactions between factors
