Climate and socio‐economic factors explain differences between observed and expected naturalization patterns of European plants around the world
Robin Pouteau, Wilfried Thuiller, Carsten Hobohm, Caroline Brunel, Barry J. Conn, Wayne Dawson, Michele de Sá Dechoum, Aleksandr L. Ebel, Franz Essl, Ori Fragman‐Sapir, Trevor S. Fristoe, Nejc Jogan, Holger Kreft, Bernd Lenzner, Carsten Meyer, Jan Pergl, Petr Pyšek, Alla V. Verkhozina, Patrick Weigelt, Qiang Yang, Elena Yu. Zykova, Svetlana Aćić, Emiliano Agrillo, Fabio Attorre, Ariel Bergamini, Christian Berg, Erwin Bergmeier, Idoia Biurrun, Steffen Boch, Gianmaria Bonari, Zoltán Botta‐Dukát, Helge Bruelheide, Juan Antonio Campos, Andraž Čarni, Laura Casella, María Laura Carranza, Milan Chytrý, Renata Ćušterevska, Michele De Sanctis, Jürgen Dengler, Panayotis Dimopoulos, Rasmus Ejrnæs, Jörg Ewald, Giuliano Fanelli, Federico Fernández‐González, Rosario G. Gavilán, Jean‐Claude Gégout, R. Haveman, Maike Isermann, Ute Jandt, Florian Jansen, Borja Jiménez‐Alfaro, Ali Kavgacı, Larisa Khanina, Ilona Knollová, Анна Куземко, Maria Lebedeva, Jonathan Lenoir, Tatiana Lysenko, Corrado Marcenò, В. Б. Мартыненко, Jesper Erenskjold Moeslund, Ricarda Pätsch, Remigiusz Pielech, Valerijus Rašomavičius, I. de Ronde, Eszter Ruprecht, Solvita Rūsiņa, П. С. Широких, Jozef Šibík, Urban Šilc, Angela Stanisci, Zvjezdana Stančić, Jens‐Christian Svenning, Grzegorz Swacha, Pavel Dan Turtureanu, Milan Valachovič, Kiril Vassilev, S. M. Yamalov, Mark van Kleunen
Abstract
Abstract Aim The number of naturalized (i.e. established) alien species has increased rapidly over recent centuries. Given the differences in environmental tolerances among species, little is known about what factors determine the extent to which the observed size of the naturalized range of a species and hence the extent to which the observed richness of naturalized species of a region approach their full potential. Here, we asked which region‐ and species‐specific characteristics explain differences between observed and expected naturalizations. Location Global. Time period Present. Major taxa studied Vascular plants. Methods We determined the observed naturalized distribution outside Europe for 1,485 species endemic to Europe using the Global Naturalized Alien Flora (GloNAF) database and their expected distributions outside Europe using species distribution models. First, we investigated which of seven socio‐economic factors related to introduction pathways, anthropogenic pressures and inventory effort best explained the differences between observed and expected naturalized European floras. Second, we examined whether distributional features, economic use and functional traits explain the extent to which species have filled their expected ranges outside Europe. Results In terms of suitable area, more than 95% of expected naturalizations of European plants were not yet observed. Species were naturalized in only 4.2% of their suitable regions outside of Europe (range filling) and in 0.4% of their unsuitable regions (range expansion). Anthropogenic habitat disturbance primarily explained the difference between observed and expected naturalized European floras, as did the number of treaties relevant to invasive species. Species of ornamental and economic value and with large specific leaf area performed better at filling and expanding beyond their expected range. Main conclusions The naturalization of alien plant species is explained by climate matching but also by the regional level of human development, the introduction pressure associated with the ornamental and economic values of the species and their adaptation to disturbed environments.