title: 'Bigger data' on scale-dependent effects of invasive species on biodiversity cannot overcome confounded analyses: a comment on Stohlgren & Rejmánek (2014).
abstract: A recent study by Stohlgren & Rejmánek (SR: Stohlgren TJ, Rejmánek M. 2014 Biol. Lett. 10. (doi:10.1098/rsbl.2013.0939)) purported to test the generality of a recent finding of scale-dependent effects of invasive plants on native diversity; dominant invasive plants decreased the intercept and increased the slope of the species-area relationship. SR (2014) find little correlation between invasive species cover and the slopes and intercepts of SARs across a diversity of sites. We show that the analyses of SR (2014) are inappropriate because of confounding causality.
authors.affiliation: German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany jonathan.chase@idiv.de.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Chase
authors.affiliation: Center for Tropical Forest Science-Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Washington DC 20560, USA.
authors.forename: Kristin I
authors.initials: KI
authors.lastname: Powell
authors.affiliation: German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany Department of Biology, Washington University in Saint Louis, Saint Louis, MO 63130, USA.
authors.forename: Tiffany M
authors.initials: TM
authors.lastname: Knight
mesh_terms: D044822:Biodiversity; D053476:Extinction, Biological; D029624:Ferns / Q000502:physiology*; D058865:Introduced Species; D031239:Lonicera / Q000502:physiology*; D029590:Myricaceae / Q000502:physiology*; D010944:Plants / Q000145:classification*
keywords: causality; invasive species; species–area relationship