For the first time, biologists have created a comprehensive list of all non-loyal species that have established themselves as permanent guests in Germany. The survey contains their regions of origin and their current habitats. Accordingly, 1962 live invasive species, especially plants and insects. They mainly come from neighboring European countries, but also from Asia and North America. The effects of immigrants on local ecosystems and the economy are still largely unknown. However, some known examples show that the consequences for humans and nature can be drastic.
Animals that originally come from foreign regions have lived in Germany for a long time. The Dam deer (Dama Dama), the European wild rabbits (Oryctolagus Cuniculus), the hunting fiber (Phasianus Colchicus) and the Rothuhn (Alectoris Rufa) were deliberately introduced to hunting about 1000 years ago. But many other species came to us unintentionally and there are more and more. “While in the past animals and plants were mainly brought into the country for hunting and leisure activities, the introductory routes of non-local species have also changed with global trade and changed human mobility,” explains Philipp Haubrock from Senckenberg Research Institute and Nature Museum Frankfurt.
Many invasive organisms today come to Germany through agriculture, tourism, private animal husbandry and in packaging or products from online trading. “Due to its central location in Europe and its extensive trade network, Germany is particularly susceptible to the introduction and spread of non-local species,” says Haubrock.
Documented almost 2000 invasive species
But how strong are the consequences of these developments? How many species that were not originally native to Germany now live here permanently? Researchers around Haubrock have now investigated this question and have created a comprehensive list of all invasive species in Germany for the first time, including their regions of origin and the effects on the affected habitats. For this they summarized various existing data surveys.
This inventory showed that in Germany there were established, non -regional species from 594 families and 35 tribes – far more was documented than in previous studies. “Most of the introduced species are plants, closely followed by insects and – at a greater distance – of vertebrates. Around 80 percent of these species live on land, some occur in wetlands. Only a small part – less than five percent – colonizes freshwater habitats or other special habitats,” reports Haubock. About eight percent of the non -regional species are sea creatures.
The animals and plants were most common from the northern hemisphere, from neighboring European countries and from Asia, but also introductions from North America occurred very often. Accordingly, the living beings were often transported to us from a distance. The origin of 335 species is unknown. The newcomers then settled primarily in southern Germany: “Most established, invasive species were reported in Bavaria, closely followed by Baden-Württemberg, Hesse, Saxony and North Rhine-Westphalia,” said Haubrock. Thuringia and Saxony-Anhalt also recorded high numbers with over 1000 species.
Effects often still unknown
The World Biodiversity Council IPBES puts the economic damage through invasive species in Europe at around $ 140 billion annually. But what consequences the individual local species have for habitats in Germany is largely unclear, as the survey showed. “In 97.9 percent of these species, the effects on domestic ecosystems and the economy are not covered,” said Haubrock. So far, hardly any damage has so far been proven by comparatively common species such as the raccoons (Procyon Lotor) or the Nilgans (alopoche Aegyptiaca).
But that does not necessarily mean that the presence of the non -regional species has no consequences for domestic nature. “For example, the Nilgans, which originally comes from Africa and has spread greatly in Germany since the 1980s, compete with domestic water birds for breeding sites and food. With its aggressive behavior, it can interfere with local ecosystems and endanger the biodiversity. It also represents a problem for agriculture,” explains fields and plants, “explains Haubrock. The pollen or leaves of some invasive plants can also trigger severe allergies in humans, such as the mugwort grape cabbage (Ambrosia Artemisiifolia) from North America and the giant bears (Heracleum Mantegazzianum) from the Caucasus.
Despite the existing knowledge gaps, the catalog created can now provide authorities, politicians and other organizations responsible for nature conservation, which invasive species are already available in Germany, how they are spreading and what effects they can have. “The aim is to develop effective strategies for the management of these species in good time. A list ordered by priorities enables resources to use and concentrate the efforts on the most urgent challenges,” explains Haubrock. In addition, the catalog can help to inform society about prominent examples and the risks of invasive species. This could prevent further unintentional introductions and propagation in the future.
Source: Senckenberg Society for Natural Research; Specialist articles: Environmental Sciences Europe, DOI: 10.1186/S12302-025-01094-W