title: How do cold-sensitive species endure ice ages? Phylogeographic and paleodistribution models of postglacial range expansion of the mesothermic drought-tolerant conifer Austrocedrus chilensis.
abstract: In view of global climate change, it is important to understand the responses of tree species to climate changes in the past. Combinations of phylogeographic analysis of genetic evidence, coupled with species distribution models (SDMs), are improving our understanding on this subject. We combined SDMs and microsatellite data from populations of the entire range of Austrocedrus chilensis, a dominant mesotherm (cold-sensitive) conifer of dryland forests of the southern Andes, to test the hypothesis of long-distance postglacial migration from northern and warmer refugia at the Last Glacial Maximum (LGM). The SDM indicated suitable conditions for Austrocedrus in northern Chile (western) at the LGM and largely unsuitable conditions in Argentina (eastern). Population genetic diversity and effective population sizes within populations decreased southward along the Andes, consistent with the hypothesis of long-distance dispersal from a northern refugium. Results support the hypothesis of one (or a few) warmer (low latitude) refugia in Chile for Austrocedrus. On balance, the evidence suggests that in contrast to cold-tolerant tree taxa with the capacity to fast-track postglacial warming thanks to local refugia, cold-sensitive species might have undergone long-distance range expansion, lagging behind progressive climate change throughout the Holocene.
authors.affiliation: Laboratorio Ecotono-INIBIOMA-CONICET, Universidad Nacional del Comahue, Quintral 1250, Bariloche, 8400, Río Negro, Argentina.
authors.forename: Cintia P
authors.initials: CP
authors.lastname: Souto
authors.affiliation: Laboratorio Ecotono-INIBIOMA-CONICET, Universidad Nacional del Comahue, Quintral 1250, Bariloche, 8400, Río Negro, Argentina.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kitzberger
authors.affiliation: Laboratorio Ecotono-INIBIOMA-CONICET, Universidad Nacional del Comahue, Quintral 1250, Bariloche, 8400, Río Negro, Argentina.|Universidad Nacional de Río Negro, Sede Andina, Bariloche, 8400, Río Negro, Argentina.
authors.forename: Marina P
authors.initials: MP
authors.lastname: Arbetman
authors.affiliation: Laboratorio Ecotono-INIBIOMA-CONICET, Universidad Nacional del Comahue, Quintral 1250, Bariloche, 8400, Río Negro, Argentina.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Premoli
mesh_terms: D002677:Chile; D057231:Climate Change; D003080:Cold Temperature; D029779:Cupressaceae / Q000235:genetics*; D014644:Genetic Variation; D046448:Ice Cover; D007178:Inbreeding; D018895:Microsatellite Repeats; D008962:Models, Theoretical; D058974:Phylogeography
keywords: Last Glacial Maximum (LGM) refugia; Migrate; glaciations; microsatellite markers; species distribution models (SDMs)