Trait-environment relationships at different stages of the introduction process 55 Trait–environment relationships of plant species at different stages of the introduction process Marija Milanović 1,2 , Sonja Knapp 1,3 , Petr Pyšek 4,5 , Ingolf Kühn 1,2,6 1 Helmholtz Centre for Environmental Research – UFZ, Dept. Community Ecology, eodor-Lieser-Str. 4, 06120 Halle, Germany 2 Martin Luther University Halle-Wittenberg, Geobotany and Botanical Garden/ Institute for Biology, Am Kirchtor 1, 06108 Halle, Germany 3 Technische Universität Berlin, Department of Ecology, Rothenburgstr. 12, 12165 Berlin, Germany 4 Czech Academy of Sciences, Institute of Botany, De- partment of Invasion Ecology, 25243 Průhonice, Czech Republic 5 Department of Ecology, Faculty of Science, Charles University, Viničná 7, 12844 Prague, Czech Republic 6 German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103 Leipzig, Germany Corresponding author: Marija Milanović (marija.milanovic@ufz.de) Academic editor: J. Kollmann  |  Received 2 March 2020  |  Accepted 7 May 2020  |  Published 1 July 2020 Citation: Milanović M, Knapp S, Pyšek P, Kühn I (2020) Trait–environment relationships of plant species at different stages of the introduction process. NeoBiota 58: 55–74. https://doi.org/10.3897/neobiota.58.51655 Abstract e success of alien plant species can be attributed to differences in functional traits compared to less suc- cessful aliens as well as to native species, and thus their adaptation to environmental conditions. Studies have shown that alien (especially invasive) plant species differ from native species in traits such as specific leaf area (SLA), height, seed size or flowering period, where invasive species showed significantly higher values for these traits. Different environmental conditions, though, may promote the success of native or alien species, leading to competitive exclusion due to dissimilarity in traits between the groups. However, native and alien species can also be similar, with environmental conditions selecting for the same set of traits across species. So far, the effect of traits on invasion success has been studied without considering environmental conditions. To understand this interaction we examined the trait–environment relation- ship within natives, and two groups of alien plant species differing in times of introduction (archaeophytes vs. neophytes). Further, we investigated the difference between non-invasive and invasive neophytes. We analyzed the relationship between functional traits of 1,300 plant species occurring in 1000 randomly se- lected grid-cells across Germany and across different climatic conditions and land-cover types. Our results show that temperature, precipitation, the proportion of natural habitats, as well as the number of land- cover patches and geological patches affect archaeophytes and neophytes differently, regarding their level of urbanity (in neophytes negative for all non-urban land covers) and self-pollination (mainly positive for archaeophytes). Similar patterns were observed between non-invasive and invasive neophytes, where additionally, SLA, storage organs and the beginning of flowering were strongly related to several environ- Copyright Marija Milanović et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. NeoBiota 58: 55–74 (2020) doi: 10.3897/neobiota.58.51655 http://neobiota.pensoft.net RESEARCH ARTICLE Advancing research on alien species and biological invasions A peer-reviewed open-access journal NeoBiota