Invasive alien species may soon cause dramatic global loss of biodiversity

An increase of 20 to 30 percent of non-native (exotic) invasive species would lead to a dramatic future loss of biodiversity worldwide. This is the conclusion of a study carried out by an international team of researchers led by Franz Essl and Bernd Lenzner of the University of Vienna. It has been published in the magazine. Global Biology Change.

Human activities intentionally and unintentionally introduce more and more plant and animal species to new regions of the world, for example, through freight or tourism.

Some of these alien species have negative consequences for biodiversity and human well-being, for example, by displacing native species or transmitting diseases. However, while we have relatively good information on the historical spread of alien species, there is still little knowledge about their future development.

“At the moment it is not yet possible to generate accurate predictions based on computer models of how the spread and impact of alien species will change in the future. Therefore, expert evaluations through standardized surveys are an important tool for obtaining a better understanding of the causes and consequences of the spread and impact of alien species in the coming decades, “says Franz Essl.

The study shows that a 20-30 percent increase in the number of newly introduced alien species is considered sufficient to cause a massive loss of global biodiversity, a value that is likely to be reached soon, as the number of introduced species is constantly increasing.

Climate change and increased trade momentum

Furthermore, humans are the main driver of the future spread of alien species. Experts identify three main reasons, mainly the increasing global transport of goods, followed by climate change and then the impacts of economic development, such as energy consumption and land use. The study also shows that the spread of alien species can be greatly slowed by ambitious countermeasures.

The researchers also investigated the influence of the increase in exotic species in different regions of the world: for example, tourism is a major driver of biological invasions in tropical and subtropical regions, while climate change favors the survival and establishment of exotic species in the future, especially in temperate and polar regions.

“Our study illustrates the space of options we currently have to reduce future impacts of alien species,” says Bernd Lenzner.

“The results form an important scientific basis for the future development of international agreements such as the Sustainable Development Goals or the Convention on Biological Diversity. In this way, we can reduce the negative impacts of exotic species on global biodiversity and our society.”

Thirty-eight researchers from across Europe, North and South America, New Zealand and South Africa participated in the study.

Helen Roy of the UK Center for Ecology and Hydrology, one of the co-authors, says: “There has been a rapid escalation in the number of non-native species being transported and introduced by humans worldwide; the adverse effects of some of these so-called non-native invasive species on biodiversity and ecosystems has been extensively documented.

“It is now critical that we work collaboratively to predict future patterns so that we can report appropriate actions in the future, such as improving biosecurity to prevent further introductions of the most damaging invasive non-native species.”

Provided by the UK Center for Ecology and Hydrology