Exotic Invaders Controlling the Spread of Aggressive Nonindigenous Plants Is a Difficult and Costly Proposition

Article excerpt

IF YOU SIT still long enough, you can see it grow. Watch it closely and you'll see it slowly stretch green, viney fingers toward its next victim: a tree, a shrub, a power line.

What you're watching is the disheartening growth of kudzu - known by many as the plant that ate the South. And you can watch it in Missouri and Illinois.

Years ago, kudzu, otherwise known as Pueraria lobata, was promoted by the U.S. Department of Agriculture for erosion control and forage. Kudzu, able to grow six to 10 inches a day, was happy to oblige the USDA. But then it became greedy, overgrowing vegetation and draping power lines, poles and billboards anywhere near it. Kudzu has surfaced in Missouri and Illinois and has been the subject of eradication efforts in both. Still, although conservation officials say the plant should be watched, they don't expect kudzu to wreak havoc in these two states in quite the same fashion it has in the South. "You just don't see it scrambling over trees like you do down South," says Tim Smith, a botanist with the Missouri Department of Conservation. What Missouri and Illinois have that the South doesn't: cold weather. And cold is no friend to kudzu. But kudzu does have other friends, a whole range of what conservationists refer to as exotic invaders, or nonindigenous plants that were brought to this country by ship, by humans or other means, sometimes intentionally, sometimes by accident. Some of those outsiders aren't able to handle the change of address, and some blend in well with indigenous species and don't bring notice to themselves. But others are problematic. Not only do they like it here, they want to take over, often resulting in the killing off of native plants and animals. Billions of dollars have been spent in this country to eradicate or at least control nonindigenous species such as kudzu. From agriculture to highway departments on the state and federal levels, costly efforts are being made to deal with the problem. But the fight goes on. Several exotic invaders have made serious forays into Missouri and Illinois, some of which have been halted, others of which have state officials doing whatever they can to stop them. "They'll be knocking at our doors soon," says Don Kurz, assistant chief of the Missouri Department of Conservation's natural history division. The now-disbanded U.S. Office of Technology Assessment issued a lengthy report three years ago on nonindigenous species and their impact on this country. The report said that 4,500 species of foreign origin had established populations in this country and that almost all U.S. crops, plants and domesticated animals originated outside this country. …