Abstract
Climate warming is supposed to enlarge the area climatically suitable to the naturalization of alien garden plants in temperate regions. However, the effects of a changing climate on the spread of naturalized ornamentals have not been evaluated by spatially and temporarily explicit range modelling at larger scales so far. Here, we assess how climate change and the frequency of cultivation interactively determine the spread of 15 ornamental plants over the 21st century in Europe. We coupled species distribution modelling with simulations of demography and dispersal to predict range dynamics of these species in annual steps across a 250 × 250 m raster of the study area. Models were run under four scenarios of climate warming and six levels of cultivation intensity. Cultivation frequency was implemented as size of the area used for planting a species. Although the area climatically suitable to the 15 species increases, on average, the area predicted to be occupied by them in 2090 shrinks under two of the three climate change scenarios. This contradiction obviously arises from dispersal limitations that were pronounced although we assumed that cultivation is spatially adapting to the changing climate. Cultivation frequency had a much stronger effect on species spread than climate change, and this effect was non‐linear. The area occupied increased sharply from low to moderate levels of cultivation intensity, but levelled off afterwards. Our simulations suggest that climate warming will not necessarily foster the spread of alien garden plants in Europe over the next decades. However, climatically suitable areas do increase and hence an invasion debt is likely accumulating. Restricting cultivation of species can be effective in preventing species spread, irrespective of how the climate develops. However, for being successful, they depend on high levels of compliance to keep propagule pressure at a low level.
Highlights
The number of species establishing populations outside their native ranges has increased exponentially during the recent century, and this trend is unlikely to slow down in the future (Seebens et al 2017)
Restricting cultivation of species can be effective in preventing species spread, irrespective of how the climate develops. For being successful, they depend on high levels of compliance to keep propagule pressure at a low level
Climate change is expected to increase the likelihood that further species from this pool escape cultivation because many garden plants have been introduced from warmer native ranges (Maurel et al 2016, Dullinger et al 2017, Haeuser et al 2018)
Summary
The number of species establishing populations outside their native ranges has increased exponentially during the recent century, and this trend is unlikely to slow down in the future (Seebens et al 2017). Some of these alien species become invasive, i.e. they manage to spread rapidly and maintain large populations over an extended area (Blackburn et al 2011). As human cultivation represents an efficient dispersal pathway, areas becoming suitable under climate change may, become more rapidly colonized by escaping ornamentals than by non-cultivated species which have to rely on natural dispersal means (Van der Veken et al 2008, Corlett and Westcott 2013). The implications that cultivation intensity and spatial cultivation patterns may have on the range dynamics of escaping ornamentals under a changing climate have hardly been evaluated so far, at least on a continental extent
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
