title: The role of sea ice for vascular plant dispersal in the Arctic.
abstract: Sea ice has been suggested to be an important factor for dispersal of vascular plants in the Arctic. To assess its role for postglacial colonization in the North Atlantic region, we compiled data on the first Late Glacial to Holocene occurrence of vascular plant species in East Greenland, Iceland, the Faroe Islands and Svalbard. For each record, we reconstructed likely past dispersal events using data on species distributions and genetics. We compared these data to sea-ice reconstructions to evaluate the potential role of sea ice in these past colonization events and finally evaluated these results using a compilation of driftwood records as an independent source of evidence that sea ice can disperse biological material. Our results show that sea ice was, in general, more prevalent along the most likely dispersal routes at times of assumed first colonization than along other possible routes. Also, driftwood is frequently dispersed in regions that have sea ice today. Thus, sea ice may act as an important dispersal agent. Melting sea ice may hamper future dispersal of Arctic plants and thereby cause more genetic differentiation. It may also limit the northwards expansion of competing boreal species, and hence favour the persistence of Arctic species.
authors.affiliation: UiT-The Arctic University of Tromsø, Tromsø, Norway inger.g.alsos@uit.no.
authors.forename: Inger Greve
authors.identifier: 0000-0002-8610-1085
authors.initials: IG
authors.lastname: Alsos
authors.affiliation: UiT-The Arctic University of Tromsø, Tromsø, Norway.
authors.forename: Dorothee
authors.initials: D
authors.lastname: Ehrich
authors.affiliation: Centre for Past Climate Studies, and Arctic Research Centre, Department of Geoscience, Aarhus University, Aarhus, Denmark.
authors.forename: Marit-Solveig
authors.identifier: 0000-0002-1973-5969
authors.initials: MS
authors.lastname: Seidenkrantz
authors.affiliation: GEUS, Copenhagen, Denmark.
authors.forename: Ole
authors.initials: O
authors.lastname: Bennike
authors.affiliation: Dendroøkologen, Skogåsvegen 6, NO-9011 Tromsø, Norway.
authors.forename: Andreas Joachim
authors.identifier: 0000-0002-8647-6645
authors.initials: AJ
authors.lastname: Kirchhefer
authors.affiliation: Faculty of Earth Sciences, University of Iceland, Reykjavík, Iceland.
authors.forename: Aslaug
authors.initials: A
authors.lastname: Geirsdottir
mesh_terms: D001110:Arctic Regions; D057231:Climate Change; D019669:Embryophyta; D046448:Ice Cover; D062312:Islands; D063148:Plant Dispersal; D014934:Wood
keywords: Arctic; climate change; driftwood; plant colonization; plant dispersal; sea ice