As climate change continues, the likelihood of southern plant species migrating to northern regions increases. In both Europe and America, many invasive plant species originate from their own continents, often hailing from warmer regions closer to the equator. Climate change may exacerbate this phenomenon.
An international research team, led by the University of Konstanz and featuring biodiversity researchers Franz Essl and Bernd Lenzner from the University of Vienna, recently published a study in the journal Science Advances, reaching the conclusion outlined above.
When people introduce plant or animal species beyond their natural habitats, it can have severe ecological consequences in the newly colonized areas. This includes the displacement of native species by newcomers, disrupting the existing ecosystems. The ecological damage resulting from the loss of native biodiversity also incurs significant economic costs, estimated by the World Biodiversity Council in its 2023 report at a minimum of 400 billion dollars (371 billion euros) annually.
While many think of alien species as those arriving from distant lands, this research, exemplified by Europe, Australia, North, and South America, led by biologist Mark van Kleunen from Konstanz, reveals that a substantial portion of the problem involves species from within their own continents. Notably, in Europe and North America, more than half (57%) of alien plant species successfully establishing themselves in new areas originally hail from their own continent. However, Australia shows a lower proportion in this regard.
Recurring patterns in dispersal within a continent
Across Europe, North and South America, researchers also identified common patterns in the spread of alien species. In the majority of cases, species spread within continents tended to move from regions closer to the equator towards the poles. Franz Essl explains, “We found that, in addition to native species moving northward, humans are predominantly responsible for the northward spread of alien species.”
Their study delved into the roles of human activities, climate factors, and geography in the intracontinental spread of alien plants. They revealed that long distances and significant climatic differences acted as barriers to spread. Bernd Lenzner adds, “The closer an area is to a species’ original distribution and the more similar the climate, the easier it is for alien species to establish themselves.”
Regarding the implications of climate change, the researchers conclude that it will accelerate the intracontinental spread of alien plants. As climate change progresses, it will increasingly favor the colonization of heat-loving alien species. This, in turn, can lead to substantial negative impacts on biodiversity and the economies of the regions receiving these species, as noted by Essl.
Source: University of Vienna