by James Ridgeway and Jeffrey St. Clair
At the turn of the century, the majestic American chestnut tree filled up the eastern forests and supported an entire complex ecosystem. By 1950, a rapidly spreading fungus - recently traced to a source in Japan - had virtually wiped out the chestnut. In the 1970s, the elm trees that lined the streets of New York City fell prey to Dutch Elm disease, a plague that spread westward and destroyed two-thirds of the nation's elms. The apparent source of the disease was a single imported log that rode the rails west from New York through Pennsylvania and into Ohio.
Today, scientists are in a panic over the threat to another abundant American tree: the maple. The source of their worries is a small, spotted bug found crawling out of a Brooklyn maple tree. The discovery of the Asian Long Horn Beetle - brought in this time from China - has led some scientists to call for a preemptive strike that would cost the borough's streets and parks all of their maple trees. It has also brought home questions about loosening environmental regulations in a time of unrestricted international trade.
More than 800 million trees in New York - covering 62 percent of the state's 18 million acres of forested land - are possible targets of the bug. Losses could run into the billions of dollars.
Unfortunately, the discovery of the Brooklyn bug presages a much broader threat to America's already-dwindling forests. The Asian Long Horn Beetle is just one of a new wave of invading pests and diseases with names like the Asian gypsy moth and the pine bark beetle and the Mexican canker, brought to American shores in increasing numbers as the result of increased - and increasingly unregulated - foreign trade. Many of these exotic insects and fungi are carried on logs that have been cut down by international companies that are searching out wood supplies in the heart of the world's few remaining primal forests. "One of the real problems," says Fields Cobb Jr., a University of California forest pathologist, "is that as we start logging off the tropics and other remote areas it will be very easy to overlook potentially dangerous pests and diseases. These disease-causing agents are obscure in their native habitat, because natural forests in diverse ecosystems tend to suppress widespread pest outbreaks." When these new diseases are brought into the US, they can destroy not only species, but whole ecosystems. The chestnut, for example, "was an unsurpassed source of food for wildlife," says Cobbs. "Dozens of species depended on it, including the bald eagle." In addition, Cobbs notes, the place of the chestnut tree was taken by oaks of lesser quality, which opened the way to the emergence of another deadly disease called oak wilt, now threatening all the oaks in the eastern forests, and making the eastern forests much more susceptible to the ravages of gypsy moths.
Yet another threat looms in the form of an enormous import program involving hundreds of companies eager to import timber from Siberia. A USDA team reported in 1991, "this assessment clearly demonstrates that the risk of significant impacts to North American forests is great," running anywhere from $25 million in the best of circumstances to $58 billion in a worst case scenario.
The US banned the import of raw Siberian logs in 1990, citing among other things the threat to the Douglas fir by the Asian gypsy moth and the spruce bark beetle. Then, in 1994 it proposed new rules that would effectively drop the ban. A lawsuit and injunction on environmental grounds preserved the import ban until early this year; forest activists are anxiously watching the situation.
Excerpted from A Pocket Guide to Environmental Bad Guys by James Ridgeway and Jeffrey St. Clair, Thunder's Mouth Press, 1998.
Invasion of the maple snatchers