Invasive species endanger native flora and fauna

In its 2019 Report on Invasive Alien Species, IPBES estimates the cost of the proliferation of such creatures at $423 billion. When you look at the influence of these invasive alien species, you are dealing with ‘exponential’ – ie escalating – growth, explains University of Vienna ecologist and biodiversity researcher Franz Essl, who was involved in the report. Since the 1970s, documented costs per decade have quadrupled.

‘We have a big problem’
Hanno Seebens of the Senckenberg Research Center for Biodiversity and Climate in Frankfurt am Main explained at a press conference organized by the German Science Media Center (SMC) that the phenomenon has basically been related to a “long-term” increase since the 1950s. The report, which was available for the first time in this comprehensive form, made it surprisingly clear that developments around the world actually “look the same”, according to the lead author of the chapter “Synthesis of Past and Future Trends” in the IPBES- paper.

“It’s going up steeply,” and there’s no reason why the process should be reversed. On the contrary: by the year 2050, the researchers expect 36 percent of new non-native species. “We have a huge problem” that still gets too little attention, also stated Sven Bacher of the University of Friborg (Switzerland) and lead author of the chapter “Ecological, economic and social consequences” in the report.

The extinction of native species opens the door for invasive species
Experts have been working for years to analyze more than 13,000 scientific publications worldwide, and the voting process has been running since 2019 and has now been completed at the IPBES General Assembly in Bonn. The synthesis report also shows, among other things, that neobiota were involved in more than 60 percent of documented species extinctions. In some cases they were even the main cause, says Essl: ‘These are not isolated cases.’ According to this data, invasive, non-native species are one of the main drivers of species loss, the loss of ecosystem services and, ultimately, of important preconditions for people’s economic and health well-being.

In our latitudes, for example, the phenomenon is clearly visible for hikers for whom the high-growing Himalayan balsam, which is native to Asia and introduced as an ornamental plant, makes it difficult to see rivers, for those who are allergic to pollen, for whom the ragweed from North America extends the hay fever season, or for farmers, for whom pests introduced in recent decades have resulted in crop failures. The phenomenon can therefore also have an impact on food security.

More than 2000 alien species in Austria
As a result of global warming, the animals, plants or fungi that have often ended up in new regions via the ever-closer global trade networks often find good living conditions in areas that are new to them. In Austria there are now more than 2000 neobiota.

For example, the robinia from North America. In the Donauauen National Park, for example, the tree is responsible for the destruction of valuable flower meadows. The corn rootworm is also spreading in this country. If it infects corn plants, it causes great economic damage. The Asian tiger mosquito has also felt comfortable in our latitudes. It is considered a possible carrier of 20 different pathogens. The increasing distribution of the quagga mussel in the Austrian lakes is another prominent example of an invasive species with major regional consequences. The cute-looking immigrants from North America called raccoons or American minks (minks) are also causing problems in many areas.

Biological Invasion
When these species displace native animals and plants and massively transform ecosystems, it is called a biological invasion. In any case, the ‘negative effects’ of such developments would more than outweigh the rather scarce and often regionally limited positive effects, explains Bernd Lenzner of the Department of Botany and Biodiversity Research at the University of Vienna, who was also involved in the creation of the 1000 page paper.

An example of another invasive species: the Asian hornet

With a summary, the World Biodiversity Council mainly addresses politicians and the general public. Lenzner emphasized that the aim was to bring more attention to the globally virulent subject – and to show that something can be done about the virtually unrestrained spread to date. There are a few examples of people trying to control the problem of imported and multiplying rats or mice, especially on hard-hit islands like New Zealand.

“Fight Early”
In any case, the greatest opportunities for containment arise when potentially dangerous neobiota are quickly identified and controlled. The report also lists prevention and species screening as the most cost-effective and effective measures, Lenzner stressed. The ‘initial phases’ of developments must be better recognized and utilized. The later you take countermeasures, the harder, more expensive and less promising it becomes.

Overall, however, many places lack an overview of the detailed processes involved in invasive alien species, the scientists complain. Despite some question marks, one sees a “clear dynamic” in the direction of exacerbating the problems. Conversely, avoided introductions are, of course, almost never registered. Essl: “The successes that are partly due to legislative measures are often invisible.”