Dimensions of invasiveness: Links between local abundance, geographic range size, and habitat breadth in Europe’s alien and native floras

Abstract

Understanding drivers of success for alien species can inform on potential future invasions. Recent conceptual advances highlight that species may achieve invasiveness via performance along at least three distinct dimensions: 1) local abundance, 2) geographic range size, and 3) habitat breadth in naturalized distributions. Associations among these dimensions and the factors that determine success in each have yet to be assessed at large geographic scales. Here, we combine data from over one million vegetation plots covering the extent of Europe and its habitat diversity with databases on species’ distributions, traits, and historical origins to provide a comprehensive assessment of invasiveness dimensions for the European alien seed plant flora. Invasiveness dimensions are linked in alien distributions, leading to a continuum from overall poor invaders to super invaders—abundant, widespread aliens that invade diverse habitats. This pattern echoes relationships among analogous dimensions measured for native European species. Success along invasiveness dimensions was associated with details of alien species’ introduction histories: earlier introduction dates were positively associated with all three dimensions, and consistent with theory-based expectations, species originating from other continents, particularly acquisitive growth strategists, were among the most successful invaders in Europe. Despite general correlations among invasiveness dimensions, we identified habitats and traits associated with atypical patterns of success in only one or two dimensions—for example, the role of disturbed habitats in facilitating widespread specialists. We conclude that considering invasiveness within a multidimensional framework can provide insights into invasion processes while also informing general understanding of the dynamics of species distributions.

Directional turnover towards larger‐ranged plants over time and across habitats

“…Species from nutrient-rich habitats are largeranged and, nutrient-demanding species increased across habitats in parallel with the displacement of smaller-by larger-ranged species. These findings largely agree with studies on plant invasions, where species with the greatest establishment success typically originate from anthropogenic, fertile habitats (Kalusová et al, 2017), and species that are most likely to be invasive and thus expand their range have an acquisitive resource strategy (Fristoe et al, 2021). We speculate that the increase in nutrient-demanding species may be partially driving the loss of small-ranged species through increased competition, particularly in habitats with denser vegetation, consistent with the stress gradient hypothesis (Bertness & Callaway, 1994).…”

“…Recent analyses suggest that instead of niche breadth, niche position is a much stronger predictor of a species’ geographic range size (Vela Diaz et al, 2020). Humans have substantially transformed Earth's terrestrial surface, creating arable, more productive habitats, which has likely benefitted range expansions of species associated with nutrient‐rich habitats and anthropogenic dispersal (Fristoe et al, 2021). Thus, the niche position of species along nutrient gradients may covary positively with range size, with large‐ranged species positioned at the more productive end of the gradient (Sonkoly et al, 2017).…”

The Matthew effect: Common species become more common and rare ones become more rare in response to artificial light at night

“…We classified the species as naturalized alien or native to Germany based on the BiolFlor database (http://www.ufz.de/biolflor). As species commonness has multiple dimensions (Fristoe et al, 2021; Rabinowitz, 1981), a species had to fulfill two criteria in order to be classified as common (the same approach to see Zhang & van Kleunen, 2019). First, the species must be known to be able to dominate local plant communities in Germany (i.e., if it can form large groups in the field according to the expert knowledge in the FloraWeb database of the Geman flora; https://www.floraweb.de/).…”

Matthew effect: common species become more common and rare ones become more rare in response to artificial light at night

“…We classified the species as naturalized alien or native to Germany based on the BiolFlor database (www.ufz.de/biolflor). As species commonness has multiple dimensions 40,41 , we classified the species as common or rare based on both occupancy frequency and local abundance level (Table S1). Specifically, we assigned a species as common if it is locally abundant (i.e.…”

“…As species commonness has multiple dimensions 40,41 , we classified the species as common or rare based on both occupancy frequency and local abundance level (Table S1).…”