Dan Kulpinski

As China prepares for the many Olympic athletes and tourists that will visit this summer, it’s already hosting some uninvited Olympic guests: invasive species.

The invaders probably snuck in amid the huge number of plants and seedlings China has imported to landscape the greater Beijing region for the Summer Olympic Games, which take place August 8-24. According to an article published in the April issue of the journal BioScience, “China’s Booming Economy Is Sparking and Accelerating Biological Invasions,” between 2002 and 2004 China imported some 60,000 kg of seeds and 31 million seedlings to plant across Beijing ahead of the Olympic Games. This enormous amount of imported plants was sure to have some hitchhiker insect pests, fungi and some unwanted species of grass seed.

“Any time you have that kind of material moving across an international boundary, you’re almost guaranteed of getting some things in that you didn’t intend to see,” explained Richard Mack in an interview. He is a co-author of the article and professor of ecology at Washington State University.

In 2006, Beijing had to launch an eradication campaign against the fall webworm, which had defoliated more than 200 plant species in the region.

This Olympic Games landscaping example reflects a larger trend. In the article, the authors describe how China’s booming economic growth over the last three decades has led to a similar boom in non-native and invasive species coming to China. This is mostly due to the way international trade unintentionally spreads plant and animal species around the globe. Plant seeds, spores, insect eggs, and fungi — all can hitch rides in shipping containers, unbeknownst to shipper or receiver.

China’s transportation network has expanded over the last 30 years, allowing people and goods to move more quickly around the country. In some cases, there is commercial access to new regions. For example, a shipping container can now go from the port of Shanghai, on the East Coast, to the western region of Tibet via rail. That wasn’t possible two years ago, said Mack.

Some numbers: The total number of harmful plants, animals and other pests seized at the Chinese border grew 10-fold between 1990 and 2005; alien animal species, mostly insects, increased 30 percent from 1990 to 2003; there were 58 invasive plants in 1995, but by 2003 the number had jumped to 188.

The article says there are now 400 known invasive species in China. Some particularly damaging ones include water hyacinth, which chokes rivers and canals; and the American vegetable leaf miner, which causes $80 million in economic damage per year. Another two the Chinese are surely not thankful for: common ragweed and giant ragweed. (Aaa-choo!)

Why is all this important? Because China loses an estimated $14.5 billion per year from its economy due to invasive species. Also because invasives could alter local communities, decrease biodiversity and possibly drive some native species to extinction. Lastly, as we spread species around the globe, the possibility exists that we could end up with a more homogenous global environment, with the same few species thriving everywhere. Places could lose their uniqueness.

Home to 30,000 species of vascular plants and 2,340 species of vertebrates, China has the third-largest amount of biodiversity in the world, behind Brazil and Colombia. So a loss of biodiversity in China could be a big loss for the world. Mack said China’s plant diversity is about twice what the United States has.

One thing I learned in my interview with Mack is the definition of invasive species. Just because a species enters a new country does not mean it is invasive. It would be called non-native — or “naturalized”, as Mack described it — but it only gets labeled “invasive” when it becomes permanently established and occupies a large range. Once it’s categorized as invasive by those parameters, “It almost has to be causing some environmental damage,” said Mack. “It may not be damage that we value, as the public, but it could definitely be causing problems with the native species. In fact it almost has to be.”

Mack said that for every 10 naturalized species there is one invasive species.

Invasive species are not unique to China; any country involved in international trade has been exposed to non-native species and possibly invaders. “We certainly see more and more evidence of species moving around the world,” said Mack.

During the Olympics, we won’t see a Beijing with defoliated trees and pests swarming everywhere, but we’ll know that the imported seedlings and grass seed represent a natural competition going on between native Chinese species and foreign species. China’s ecology is changing, just like it is around the globe — and mankind is making it happen.