Invasive non-native organisms are one of the greatest threats to the natural ecosystems of the U.S. and are destroying America’s natural history and identity. These unwelcome plants, insects and other organisms are disrupting the ecology of natural ecosystems, displacing native plant and animal species, and degrading our nation’s unique and diverse biological resources. Aggressive invaders reduce the amount of light, water, nutrients and space available to native species, alter hydrological patterns, soil chemistry, moisture-holding capacity, and erodibility, and change fire regimes. Some exotics are capable of hybridizing with native…