title: Long-distance plant dispersal to North Atlantic islands: colonization routes and founder effect.
abstract: Long-distance dispersal (LDD) processes influence the founder effect on islands. We use genetic data for 25 Atlantic species and similarities among regional floras to analyse colonization, and test whether the genetic founder effect on five islands is associated with dispersal distance, island size and species traits. Most species colonized postglacially via multiple dispersal events from several source regions situated 280 to >3000 km away, and often not from the closest ones. A strong founder effect was observed for insect-pollinated mixed maters, and it increased with dispersal distance and decreased with island size in accordance with the theory of island biogeography. Only a minor founder effect was observed for wind-pollinated outcrossing species. Colonization patterns were largely congruent, indicating that despite the importance of stochasticity, LDD is mainly determined by common factors, probably dispersal vectors. Our findings caution against a priori assuming a single, close source region in biogeographic analyses.
authors: Tromsø Museum, University of Tromsø, NO-9037 Tromsø, Norway inger.g.alsos@uit.no.
authors: Inger Greve
authors: IG
authors: Alsos
authors: Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, University of Tromsø, NO-9037 Tromsø, Norway.
authors: Dorothee
authors: D
authors: Ehrich
authors: The University Centre in Svalbard, PO Box 156, NO-9171 Longyearbyen, Norway.
authors: Pernille Bronken
authors: PB
authors: Eidesen
authors: Museum of Natural History and Archaeology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
authors: Heidi
authors: H
authors: Solstad
authors: Norwegian Institute for Nature Research, PO Box 5685 Sluppen, NO-7485 Trondheim, Norway.
authors: Kristine Bakke
authors: KB
authors: Westergaard
authors: Institute of Botany, University of Innsbruck, Sternwartestraße 15, A-6020 Innsbruck, Austria.
authors: Peter
authors: P
authors: Schönswetter
authors: Department of Organismic Biology, University of Salzburg, Hellbrunnerstraße 34, A-5020 Salzburg, Austria.
authors: Andreas
authors: A
authors: Tribsch
authors: The University Centre in Svalbard, PO Box 156, NO-9171 Longyearbyen, Norway Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, PO Box 1066 Blindern, NO-0316 Oslo, Norway.
authors: Siri
authors: S
authors: Birkeland
authors: National Centre for Biosystematics, Natural History Museum, University of Oslo, PO Box 1172 Blindern, NO-0318 Oslo, Norway.
authors: Reidar
authors: R
authors: Elven
authors: National Centre for Biosystematics, Natural History Museum, University of Oslo, PO Box 1172 Blindern, NO-0318 Oslo, Norway.
authors: Christian
authors: C
authors: Brochmann
keywords: Amplified fragment length polymorphism (AFLP); dispersal vector; founder effect; genetic diversity; islands; long-distance dispersal (LDD); postglacial; species traits