Thompson isn’t claiming that all invaders are upstanding citizens: Guam would be better off without brown tree snakes, for instance, and Australia could do without cane toads. Knapweed, which can coexist fairly peacefully with its native neighbors, continues to bloom despite the flies. As the rodent population boomed, the mice gobbled up native plant seeds with gusto, preventing them from taking root. In fact, the European flies introduced to control knapweed made a tasty snack for local deer mice. Neither tactic worked on spotted knapweed, which has spread across the continental United States since it arrived in the late 1800s. Dousing hillsides in herbicide or bringing in another species to police previously introduced plants and animals can harm natives and nonnatives alike. Zebra mussels, the pipe-clogging scourge of the Great Lakes, also act as an important food source for local waterfowl and fish, for example.Īnd eradication efforts can do more environmental damage than the invasives. Even the most disparaged offenders can bring unexpected benefits to new neighborhoods. More often than not, Thompson argues, invaders’ greatest crime is moving in after human activities have made ecosystems unsuitable for natives.
0 Comments
Leave a Reply. |