Two independent dispersals to the Southern Hemisphere to become the most widespread bipolar Carex species: biogeography of C. canescens (Cyperaceae)

About 30 plant species occur at high latitudes in both hemispheres, thus achieving a so-called bipolar distribution. Six of these species belong to Carex, of which just one, Carex canescens, occurs on two different landmasses in the Southern Hemisphere (South America and Oceania). The goals of this...

Descripción completa

Detalles Bibliográficos
Autores: Villaverde, Tamara, Escudero, Marcial, Martín Bravo, Santiago, Luceño, Modesto
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2017
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/168329
Acceso en línea:http://hdl.handle.net/10261/168329
Access Level:acceso abierto
Palabra clave:Australia
Climatic niches
Disjunction
Divergence time estimation
Glareosae
Long-distance dispersal
South America.
Descripción
Sumario:About 30 plant species occur at high latitudes in both hemispheres, thus achieving a so-called bipolar distribution. Six of these species belong to Carex, of which just one, Carex canescens, occurs on two different landmasses in the Southern Hemisphere (South America and Oceania). The goals of this study are (1) to test the various hypotheses accounting for the bipolar disjunction of C. canescens and (2) to elucidate if C. canescens migrated twice from the Northern Hemisphere to the Southern Hemisphere or if it dispersed from South America to Oceania (or vice versa). We obtained and analysed DNA sequences from the nuclear internal and external transcribed spacers (ITS and ETS) and from the plastid 5′ trnK and rps16 introns from 57 populations of C. canescens spanning its bipolar range. We characterized the species distribution climatically by adding 1995 presence data points from the Global Biodiversity Information Facility. Our results suggest a Northern Hemisphere origin of C. canescens during the Pleistocene and two independent long distance-dispersal events to South America and Australia, by either direct dispersal or mountain-hopping. Long-distance dispersal appears to be the most widespread process resulting in the bipolar distribution of Carex spp.