swissworld.org - Switzerland's official information portal

swissworld.org - Switzerland's official information portal

Your Gateway to Switzerland

Exotic plants and animals

Giant Hogweed (Heracleum mantegazzianum) (in new window)

Giant Hogweed (Heracleum mantegazzianum)© IvanTortuga / flickr.com

While many native species are under threat, the arrival in Switzerland of "exotic" plants and animals is a cause of concern. These threaten many indigenous species and in some cases are harmful to human beings. Some exotics not only compete aggressively with native species for the same habitat, but also import diseases which kill them off.

Many have been introduced wittingly or unwittingly by humans. Plants have been imported for gardens, or animals have been brought in for their meat or other quality, but have subsequently escaped. In other cases the exotics have arrived attached to clothing or in containers.

In addition, climate change has enabled species to survive which were formerly unsuited to Swiss conditions.

Unwanted plants include the giant hogweed (Heracleum mantegazzianum), a native of the Caucasus and southwest Asia, whose sap can cause severe burns and blistering, and which also erodes the banks of streams, and common ragweed (Ambrosia artemisiifolia), originally from the US, whose abundant pollen provokes hay fever and even asthma.

Animals include the American grey squirrel, which is moving northwards from Italy, and is predicted to wipe out the native squirrel if nothing is done. The American signal crayfish, whose meat is regarded as a delicacy, was discovered in northern Switzerland in 2001. It carries a fungal disease which threatens native species. The Asia tiger mosquito, which is a potential carrier of a number of viral diseases, was found in Switzerland for the first time in 2003.

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