Risk hotspots for terrestrial plant invaders under climate change at the global scale

Terrestrial plant invaders (TPIs) have a large potential to threaten plant diversity under climate change. To prevent the spread of TPIs under climate change, we must identify the risk hotspots for TPIs. However, the risk hotspots for TPIs have not yet been explicitly addressed at the global scale under climate change. Here, we selected 336 TPIs from the Invasive Species Specialist Group list and used species distribution modelling and Hot Spot Analysis to map the risk hotspots of TPIs based on the terrestrial ecoregions in the current, low and high gas concentration scenarios. The risk hotspots of TPIs were mainly distributed in South America, Europe, Australia, New Zealand and northern and southern Africa. Climate change may decrease the areas of hotspots that allow for TPI expansion, but the potential distribution probabilities of TPIs may increase in the high concentration scenario. Furthermore, TPIs, particularly herbaceous and woody ones, might still expand into critical or endangered ecoregions of these risk hotspots in the current, low and high concentration scenarios. We also need to focus on the impact of TPI expansion on both vulnerable and relatively stable ecoregions due to the increasing potential distribution probabilities of TPIs in risk hotspots and should integrate climate change into the risk assessment of plant invasion in the vulnerable and relatively stable ecoregions.