Invasive plant species all over the internet

Many invasive plants start out as imported garden or ornamental varieties that spread to the wild. Keystone

Researchers at the Swiss Federal Institute of Technology in Zurich (ETHZ) have discovered that the sale of invasive plant species over the internet is much more widespread than previously thought.

After monitoring the trade of plants across ten online platforms, including eBay, for a period of 50 days, the researchers identified 2,625 species for sale. Of those, 510 of were known to be invasive, and no fewer than 35 were on the IUCN’s list of 100 of the world’s worst invasive speciesExternal link.

Invasive species were listed by sellers in 55 different countries. “We didn’t expect the global trade in plants that are known to be invasive to be so extensive,” said Franziska Humair, the study’s first author, in a statement.

Examples of invasive plants in Switzerland include goldenrod, Himalayan balsam, and Chinese windmill palm. Most have been introduced from other countries for use in gardens and landscaping, but have since spread into wild habitats, where they compete with native species.

More research, more action

“The only way to contain invasions is by limiting the trade in potential invaders,” said research group leader Christoph Küffer of the ETHZ Institute of Integrative Biology.

“As online trade blossoms, it makes it even more urgent for the authorities to take action or for responsible large commercial nurseries to adjust their product ranges.”

The researchers say that the true number of invasive plants for sale online could be much higher, as their software programme only tracked plants listed by their scientific names, rather than common names. Only supply could be monitored, as transaction and buyer data are generally considered private.

The researchers published their findings in the journal Conservation Biology.