title: Glacial survival of boreal trees in northern Scandinavia.
abstract: It is commonly believed that trees were absent in Scandinavia during the last glaciation and first recolonized the Scandinavian Peninsula with the retreat of its ice sheet some 9000 years ago. Here, we show the presence of a rare mitochondrial DNA haplotype of spruce that appears unique to Scandinavia and with its highest frequency to the west-an area believed to sustain ice-free refugia during most of the last ice age. We further show the survival of DNA from this haplotype in lake sediments and pollen of Trøndelag in central Norway dating back ~10,300 years and chloroplast DNA of pine and spruce in lake sediments adjacent to the ice-free Andøya refugium in northwestern Norway as early as ~22,000 and 17,700 years ago, respectively. Our findings imply that conifer trees survived in ice-free refugia of Scandinavia during the last glaciation, challenging current views on survival and spread of trees as a response to climate changes.
authors.affiliation: Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
authors.forename: Laura
authors.initials: L
authors.lastname: Parducci
authors.forename: Tina
authors.initials: T
authors.lastname: Jørgensen
authors.forename: Mari Mette
authors.initials: MM
authors.lastname: Tollefsrud
authors.forename: Ellen
authors.initials: E
authors.lastname: Elverland
authors.forename: Torbjørn
authors.initials: T
authors.lastname: Alm
authors.forename: Sonia L
authors.initials: SL
authors.lastname: Fontana
authors.forename: K D
authors.initials: KD
authors.lastname: Bennett
authors.forename: James
authors.initials: J
authors.lastname: Haile
authors.forename: Irina
authors.initials: I
authors.lastname: Matetovici
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Suyama
authors.forename: Mary E
authors.initials: ME
authors.lastname: Edwards
authors.forename: Kenneth
authors.initials: K
authors.lastname: Andersen
authors.forename: Morten
authors.initials: M
authors.lastname: Rasmussen
authors.forename: Sanne
authors.initials: S
authors.lastname: Boessenkool
authors.forename: Eric
authors.initials: E
authors.lastname: Coissac
authors.forename: Christian
authors.initials: C
authors.lastname: Brochmann
authors.forename: Pierre
authors.initials: P
authors.lastname: Taberlet
authors.forename: Michael
authors.initials: M
authors.lastname: Houmark-Nielsen
authors.forename: Nicolaj Krog
authors.initials: NK
authors.lastname: Larsen
authors.forename: Ludovic
authors.initials: L
authors.lastname: Orlando
authors.forename: M Thomas P
authors.initials: MT
authors.lastname: Gilbert
authors.forename: Kurt H
authors.initials: KH
authors.lastname: Kjær
authors.forename: Inger Greve
authors.initials: IG
authors.lastname: Alsos
authors.forename: Eske
authors.initials: E
authors.lastname: Willerslev
mesh_terms: D001483:Base Sequence; D018742:DNA, Chloroplast / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D005060:Europe; D005580:Fossils; D019015:Geologic Sediments; D006239:Haplotypes; D046448:Ice Cover; D008969:Molecular Sequence Data; D009154:Mutation; D009664:Norway; D028222:Picea / Q000235:genetics; D028223:Pinus / Q000235:genetics; D012537:Scandinavian and Nordic Countries; D013995:Time
chemical_list: D018742:DNA, Chloroplast; D004272:DNA, Mitochondrial