Biogeographical analysis of rodent endemism and distributional congruence in the southern–central A ndes (north‐western A rgentina)

The recognition of areas of endemism ( AEs ) is important for conservation biology and biogeographical regionalization. Our objective was to quantitatively identify AEs and distributional congruence patterns of native rodents at the tropical/temperate transition in the central A ndes. We analysed 6200 geo‐referenced distributional records of 80 species in north‐western A rgentina using NDM / VNDM software. We found 20 AEs defined by 22 endemic species (27% of the total rodent fauna) and 34 patterns of distributional congruence in non‐endemic rodents. Geographical range congruence follows two main patterns running parallel along the A ndes. One is related to the humid eastern slopes of the A ndes ( A rgentinean Y ungas forest) and the other to the high A ndes ( A rgentinean P una plateau). Endemism was mainly restricted to the southernmost part of the Y ungas forest and adjacent dryer valleys ( M onte desert). Species diversity was highest in the n orthern sector of the A rgentinean Y ungas forest, where several species reach their southern distributional range. This incongruence among hotspots of diversity and endemism has also been also noted in diversity studies at continental and global scales. Our results provide a starting point for conservation planning in the southernmost C entral A ndes, which combines the taper of tropical diversity and range‐restricted species endemic to the tropical–temperate transition. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society , 2014, 112 , 163–179.