title: Climate change stimulates the growth of the intertidal macroalgae Ascophyllum nodosum near the northern distribution limit.
abstract: Ascophyllum nodosum is a foundation macroalgae of the intertidal zone that distributes across latitude 41.3-69.7°N. We tested the hypothesis that growth of A. nodosum near the northern distribution edge increases with warming. We retrospectively quantified the growth of eight A. nodosum populations at West Greenland and North Norway (from 64°N to 69°N). For seven populations, we measured growth rates since 1997-2002 and for one of them we extended the time series back to 1956 using published estimates. Individuals at northern populations elongated between 2.0 and 9.1 cm year-1and this variability correlated with temperature and annual ice-free days. A spatial comparison of A. nodosum growth across the species distribution range showed that Northern (and coldest) populations grew at the slowest rates. Our results demonstrate that arctic climate change enhances the growth of A. nodosum populations and suggest that their productivity may increase in response to projected global warming.
authors.affiliation: Department of Global Change Research, IMEDEA (CSIC-UIB), Miquel Marquès 21, 07190, Esporles (Illes Balears), Spain. nmarba@imedea.uib-csic.es.
authors.forename: Núria
authors.initials: N
authors.lastname: Marbà
authors.affiliation: Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600, Silkeborg, Denmark.|Arctic Research Centre, Aarhus University, Ny Munkegade 114, Building 1540, 8000, Århus C, Denmark.
authors.forename: Dorte
authors.initials: D
authors.lastname: Krause-Jensen
authors.affiliation: Department of Bioscience, Aarhus University, Ole Worms Allé 1, Building 1135, 8000, Aarhus C, Denmark.
authors.forename: Birgit
authors.initials: B
authors.lastname: Olesen
authors.affiliation: Arctic Research Centre, Aarhus University, Ny Munkegade 114, Building 1540, 8000, Århus C, Denmark.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Christensen
authors.affiliation: ArcticNet/Amundsen Science, Université Laval, Pavillon Alexandre-Vachon, Room 4081, 1045 Avenue de la Médecine, Quebec, QC, G1V 0A6, Canada.
authors.forename: Anissa
authors.initials: A
authors.lastname: Merzouk
authors.affiliation: St Catharine's College, University of Cambridge, Cambridge, CB2 1RL, UK.
authors.forename: Joao
authors.initials: J
authors.lastname: Rodrigues
authors.affiliation: Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000, Roskilde, Denmark.
authors.forename: Susse
authors.initials: S
authors.lastname: Wegeberg
authors.affiliation: Department of Biology, University of Massachusetts, Amherst, MA, 01003, USA.
authors.forename: Robert T
authors.initials: RT
authors.lastname: Wilce
mesh_terms: D001110:Arctic Regions; D044646:Ascophyllum / Q000254:growth & development*; D057231:Climate Change; D064308:Ecological Parameter Monitoring; D005843:Geography; D006116:Greenland; D046448:Ice Cover; D009664:Norway; D011157:Population Dynamics; D012621:Seasons; D013696:Temperature
keywords: Elongation; Greenland; Latitude gradient; Norway; Warming