title: Trade-offs between life-history traits at range-edge and central locations.
abstract: The allocation of resources to different life-history traits should represent the best compromise in fitness investment for organisms in their local environment. When resources are limiting, the investment in a specific trait must carry a cost that is expressed in trade-offs with other traits. In this study, the relative investment in the fitness-related traits, growth, reproduction and defence were compared at central and range-edge locations, using the seaweed Ascophyllum nodosum as a model system. Individual growth rates were similar at both sites, whereas edge populations showed a higher relative investment in reproduction (demonstrated by a higher reproductive allocation and extended reproductive periods) when compared to central populations that invested more in defence. These results show the capability of A. nodosum to differentially allocate resources for different traits under different habitat conditions, suggesting that reproduction and defence have different fitness values under the specific living conditions experienced at edge and central locations. However, ongoing climate change may threaten edge populations by increasing the selective pressure on specific traits, forcing these populations to lower the investment in other traits that are also potentially important for population fitness.
authors.affiliation: Interdisciplinary Centre of Marine and Environmental Research (CIMAR), University of Porto, Rua dos Bragas 289, Porto, P 4050-123, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Araújo
authors.affiliation: Centre of Marine Sciences, University of Algarve (CCMAR), Campus of Gambelas, Faro, 8005-139, Portugal.
authors.forename: Ester A
authors.initials: EA
authors.lastname: Serrão
authors.affiliation: Interdisciplinary Centre of Marine and Environmental Research (CIMAR), University of Porto, Rua dos Bragas 289, Porto, P 4050-123, Portugal.|Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, Porto, 4050, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Sousa-Pinto
authors.affiliation: Interdisciplinary Centre of Marine and Environmental Research (CIMAR), University of Porto, Rua dos Bragas 289, Porto, P 4050-123, Portugal.
authors.forename: Francisco
authors.initials: F
authors.lastname: Arenas
authors.affiliation: Centre of Marine Sciences, University of Algarve (CCMAR), Campus of Gambelas, Faro, 8005-139, Portugal.
authors.forename: Carla A
authors.initials: CA
authors.lastname: Monteiro
authors.affiliation: Department Biological and Environmental Sciences-Tjärnö, University of Gothenburg, Strömstad, 452 96, Sweden.
authors.forename: Gunilla
authors.initials: G
authors.lastname: Toth
authors.affiliation: Department Biological and Environmental Sciences-Tjärnö, University of Gothenburg, Strömstad, 452 96, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Pavia
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, Göteborg, 40530, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Åberg
keywords: defence; growth; life-history traits; range-edge populations; reproduction; trade-offs