Alien Invasion? An Ecologist Doubts the Impact of Exotic Species
Many conservationists have dedicated their lives to eradicating invasive plant and animal species, but Mark Davis wants them to reassess their missions
Alien Invasion? An Ecologist Doubts the Impact of Exotic Species
- Water Sucker The tamarisk tree has been called the "second-worst invasive species in the United States," and millions of dollars have been spent on its eradication. Early studies had reported that tamarisks used more water than native vegetation, and one author wrote that they sucked up "almost twice as much water per year as the major cities in southern California." Forgotten in the hubbub were later measurements that failed to replicate those studies, and no one has established whether the tamarisk causes soils to go salty or if it simply has a higher tolerance for salty soils... University of Nevada, Reno
- Fast and Loosestrife Davis's doubts date back to early attempts to eradicate purple loosestrife from around Minnesota lakes and waterways. Eradication proponents argued that the imported plant, which has spread across North America, was seriously displacing the native plant species that muskrats and ducks eat, thereby displacing the animals... Marion County
- Snakes Alive! After World War II, the brown tree snake arrived on the U.S. Pacific island of Guam, 6,100 kilometers west of Hawaii. It has since extirpated 10 of the island's 12 native forest bird species, and ecologists are now studying the wider impacts of these bird extinctions on the forest... United States Geological Survey
