title: Major shifts at the range edge of marine forests: the combined effects of climate changes and limited dispersal.
abstract: Global climate change is likely to constrain low latitude range edges across many taxa and habitats. Such is the case for NE Atlantic marine macroalgal forests, important ecosystems whose main structuring species is the annual kelp Saccorhiza polyschides. We coupled ecological niche modelling with simulations of potential dispersal and delayed development stages to infer the major forces shaping range edges and to predict their dynamics. Models indicated that the southern limit is set by high winter temperatures above the physiological tolerance of overwintering microscopic stages and reduced upwelling during recruitment. The best range predictions were achieved assuming low spatial dispersal (5 km) and delayed stages up to two years (temporal dispersal). Reconstructing distributions through time indicated losses of ~30% from 1986 to 2014, restricting S. polyschides to upwelling regions at the southern edge. Future predictions further restrict populations to a unique refugium in northwestern Iberia. Losses were dependent on the emissions scenario, with the most drastic one shifting ~38% of the current distribution by 2100. Such distributional changes might not be rescued by dispersal in space or time (as shown for the recent past) and are expected to drive major biodiversity loss and changes in ecosystem functioning.
authors.affiliation: CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Assis
authors.affiliation: Estrutura de Missão para a Extensão da Plataforma Continental (EMEPC), Rua Costa Pinto 165, 2770-042, Paço de Arcos, Portugal.
authors.forename: E
authors.initials: E
authors.lastname: Berecibar
authors.affiliation: CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: B
authors.initials: B
authors.lastname: Claro
authors.affiliation: Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, USA.
authors.forename: F
authors.initials: F
authors.lastname: Alberto
authors.affiliation: Marine Science Institute, University of California, Santa Barbara, California 93106, USA.
authors.forename: D
authors.initials: D
authors.lastname: Reed
authors.affiliation: Department of Biology, University of California, Santa Cruz, California 95064, USA.
authors.forename: P
authors.initials: P
authors.lastname: Raimondi
authors.affiliation: CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: E A
authors.initials: EA
authors.lastname: Serrão
mesh_terms: D001267:Atlantic Ocean; D044822:Biodiversity; D057231:Climate Change; D017753:Ecosystem; D044423:Kelp / Q000502:physiology*; D015233:Models, Statistical; D000459:Phaeophyceae / Q000502:physiology*; D063148:Plant Dispersal / Q000502:physiology*; D012621:Seasons