Résumé
Aims: The rapid increase in the number of species that have naturalized
beyond their native range is among the most apparent features of the
Anthropocene. How alien species will respond to other processes of future
global changes is an emerging concern and remains largely misunderstood.
We therefore ask whether naturalized species will respond to climate and
land-use change differently than those species not yet naturalized
anywhere in the world. Location: Global Methods: We investigated future
changes in the potential alien range of vascular plant species endemic to
Europe that are either naturalized (n = 272) or not yet naturalized
(1,213) outside of Europe. Potential ranges were estimated based on
projections of species distribution models using 20 future climate-change
scenarios. We mapped current and future global centres of naturalization
risk. We also analyzed expected changes in latitudinal, elevational and
areal extent of species’ potential alien ranges. Results: We showed a
large potential for more worldwide naturalizations of European plants
currently and in the future. The centres of naturalization risk for
naturalized and non-naturalized plants largely overlapped, and their
location did not change much under projected future climates.
Nevertheless, naturalized plants had their potential range shifting
poleward over larger distances, whereas the non-naturalized ones had their
potential elevational ranges shifting further upslope under the most
severe climate change scenarios. As a result, climate and land-use changes
are predicted to shrink the potential alien range of European plants, but
less so for already naturalized than for non-naturalized species. Main
conclusions: While currently non-naturalized plants originate frequently
from mountain ranges or boreal and Mediterranean biomes in Europe, the
naturalized ones usually occur at low elevations, close to human centres
of activities. As the latter are expected to increase worldwide, this
could explain why the potential alien range of already naturalized plants
will shrink less.