Human Seed Dispersal: to Antarctica?

Turns out, humans are agents in the movement of alien plant species to a place one does not think of as at risk for invasive plants: the Antarctic. And we’re not talking about a stray seed or two: [LA Times: Antarctic plants under siege from invasive species, report finds]

To get a handle on the scope of the problem, Chown and an international team of scientists surveyed nearly 5,700 tourists, scientists, ship’s crews and support staff during the 2007-08 summer season. They also vacuumed clothes, bags and other travel gear of about 850 people, finding 2,686 stowaway seeds among the detritus that they identified by species or family using photographs from plant databases.

Chown said that from the analysis, he and his colleagues estimated that more than 70,000 seeds tagged along with the human visitors during that time window.

Each visitor brought an average of 9.5 seeds, the study said. The rates were much higher for scientists: About two-fifths of scientists at research stations brought seeds with them, double the rate for tourists. Scientists doing field work brought even more.

As that previously-inhospitable continent shows more soil and milder temps as global warming proceeds, the risk of alien animals is perhaps the greater threat.

“If rodents ever got in, they’d be a real pest because rats have a habit of feeding on birds – and there’s huge, vast bird colonies in Antarctica,” Chown said. Even penguins might be at risk. “Penguins are more feisty than others, and rats don’t tend to feed on penguins. But if they were desperate they’d have a go.”