title: A phylogenetic analysis of the British flora sheds light on the evolutionary and ecological factors driving plant invasions.
abstract: Darwin's naturalization hypothesis predicts that invasive species should perform better in their novel range in the absence of close relatives in the native flora due to reduced competition. Evidence from recent taxonomic and phylogenetic-based studies, however, is equivocal. We test Darwin's naturalization hypothesis at two different spatial scales using a fossil-dated molecular phylogenetic tree of the British native and alien flora (ca. 1600 species) and extensive, fine-scale survey data from the 1998 Countryside Survey. At both landscape and local scales, invasive species were neither significantly more nor less related to the native flora than their non-invasive alien counterparts. Species invasiveness was instead correlated with higher nitrogen and moisture preference, but not other life history traits such as life-form and height. We argue that invasive species spread in Britain is hence more likely determined by changes in land use and other anthropogenic factors, rather than evolutionary history. Synthesis. The transition from non-invasive to invasive is not related to phylogenetic distinctiveness to the native community, but instead to their environmental preferences. Therefore, combating biological invasions in the Britain and other industrialized countries need entirely different strategies than in more natural environments.
authors.affiliation: Department of Life Sciences, Imperial College London, Silwood Park Campus Ascot, SL5 7PY, UK.
authors.forename: Junying
authors.initials: J
authors.lastname: Lim
authors.affiliation: Department of Life Sciences, Imperial College London, Silwood Park Campus Ascot, SL5 7PY, UK.
authors.forename: Mick J
authors.initials: MJ
authors.lastname: Crawley
authors.affiliation: National Botanic Gardens of Wales Llanarthne, Carmarthenshire, SA32 8HG, UK.
authors.forename: Natasha
authors.initials: N
authors.lastname: De Vere
authors.affiliation: 57 Aberdulais Road, Cardiff, CF14 2PH, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Rich
authors.affiliation: Department of Life Sciences, Imperial College London, Silwood Park Campus Ascot, SL5 7PY, UK ; Royal Botanic Gardens Kew, Richmond, TW9 3DS, UK.
authors.forename: Vincent
authors.initials: V
authors.lastname: Savolainen
keywords: British flora; Darwin's naturalization hypothesis; Ellenberg indicators; functional trait; invasive species; molecular phylogenetics