Broad-scale rather than fine-scale environmental variation drives body size in a wandering predator (Araneae, Lycosidae)

• Published in: Arctic, Antarctic, and Alpine Research
• Main Authors: Hein, Nils, Pétillon, Julien, Pape, Roland, Feilhauer, Hannes, Vanselow, Kim, A, Löffler, Jörg
• Other Authors: Universität Bonn = University of Bonn, Ecosystèmes, biodiversité, évolution Rennes (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Friedrich-Alexander Universität Erlangen-Nürnberg = University of Erlangen-Nuremberg (FAU), Freie Universität Berlin
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: Individual trait; random forest; Wolf spider; Norway; Pardosa palustris; [SDE.MCG]Environmental Sciences/Global Changes; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Arctic; Antarctic and Alpine Research
• Online Access: https://hal.science/hal-02364618; https://hal.science/hal-02364618/document; https://hal.science/hal-02364618/file/Hein%20et%20al-2020-Broad-scale%20rather%20than%20fine-scale%20environmental%20variation.pdf; https://doi.org/10.1080/15230430.2019.1640039

International audience Body size is one of the most important individual traits, determining various other life-history traits, including fitness. Both evolutionary and ecological factors shape the body size in arthro-pods, but the relative contribution of abiotic drivers acting at different spatial scales has been little investigated. We aimed to identify the importance of two broad-scale variables (study region and elevation) in shaping body size of the free-running and locally abundant wolf spider Pardosa palustris (LINNAEUS 1758), in contrast to the fine-scaled variable topographic position. Therefore, we set up transects along environmental gradients in the arctic-alpine ecosystems of Norway, which we analyzed using a random forest approach to identify the relative importance of topographic position, elevation, and study region on body size of P. palustris. Our approach revealed that research region was the best explanatory variable, followed by elevation and topographic position. Differences in body size were most likely a consequence of the pronounced differences in season length and the ability of P. palustris to avoid local unfavorable environmental conditions due to its high mobility.