A Friend to Aliens: Are Invasive Species Really a Big Threat? (Scientific American)

Posted on by Brendan Borrell

Plant ecologist Mark A. Davis will not participate in this year’s “Buckthorn Roundups” around his St. Paul, Minn., neighborhood. ­Davis will not tag along as these intrepid crusaders set out to eradicate the common and glossy buckthorn, two ornamental shrubs imported in the 19th century from Europe. The nonnatives have now taken over some Midwestern forests, prairies and wetlands. That is why eco-minded volunteers eagerly wrench young weeds from the soil, hack away at thick stems and douse remaining stumps with herbicides. Their hope: a return of Minnesota to its primeval state.

At one time, Davis, too, could see the logic in eradicating these “invaders.” He even advocated planting only Minnesota nativeplants on the Macalester College campus where he teaches. That changed in 1994, when he read an essay by journalist Michael Pollan in the New York Times Magazinethat made his blood boil. He bristled at Pollan’s statement that turning the “ecological clock to 1492 is a fool’s errand, futile and pointless to boot.”