title: Geographical gradients in Argentinean terrestrial mammal species richness and their environmental correlates.
abstract: We analysed the main geographical trends of terrestrial mammal species richness (SR) in Argentina, assessing how broad-scale environmental variation (defined by climatic and topographic variables) and the spatial form of the country (defined by spatial filters based on spatial eigenvector mapping (SEVM)) influence the kinds and the numbers of mammal species along these geographical trends. We also evaluated if there are pure geographical trends not accounted for by the environmental or spatial factors. The environmental variables and spatial filters that simultaneously correlated with the geographical variables and SR were considered potential causes of the geographic trends. We performed partial correlations between SR and the geographical variables, maintaining the selected explanatory variables statistically constant, to determine if SR was fully explained by them or if a significant residual geographic pattern remained. All groups and subgroups presented a latitudinal gradient not attributable to the spatial form of the country. Most of these trends were not explained by climate. We used a variation partitioning procedure to quantify the pure geographic trend (PGT) that remained unaccounted for. The PGT was larger for latitudinal than for longitudinal gradients. This suggests that historical or purely geographical causes may also be relevant drivers of these geographical gradients in mammal diversity.
authors.affiliation: Biogeography, Diversity, and Conservation Research Team, Department of Animal Biology, Faculty of Sciences, University of Malaga, 29071 Malaga, Spain. almarquez@uma.es
authors.forename: Ana L
authors.initials: AL
authors.lastname: Márquez
authors.forename: Raimundo
authors.initials: R
authors.lastname: Real
authors.forename: Marta S
authors.initials: MS
authors.lastname: Kin
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Guerrero
authors.forename: Betina
authors.initials: B
authors.lastname: Galván
authors.forename: A Márcia
authors.initials: AM
authors.lastname: Barbosa
authors.forename: Jesús
authors.initials: J
authors.lastname: Olivero
authors.forename: L Javier
authors.initials: LJ
authors.lastname: Palomo
authors.forename: J Mario
authors.initials: JM
authors.lastname: Vargas
authors.forename: Enrique
authors.initials: E
authors.lastname: Justo
mesh_terms: D000818:Animals; D001118:Argentina; D044822:Biodiversity; D002980:Climate; D004463:Ecology / Q000379:methods*; D004777:Environment; D005843:Geography; D016014:Linear Models; D008322:Mammals / Q000502:physiology*; D011157:Population Dynamics; D025341:Principal Component Analysis; D013696:Temperature