 | | |
 |  | |
 | | |
 | | |
 | | |
 | | |
 | | |
 | | |
 | | |
 | | |
 | | |
 | | |
 | | |
 | | |
 | | |
 | | |
 | | |
 | |
How do invasive species affect me?
Invasive species have severe environmental and economical impacts.
Why
you should be concerned
Estimates indicate
that invasive plants are spreading at about 4,600 acres per day on Federal
lands alone in the western United States.
Weeds have invaded approximately 17 million acres of public rangelands in the West-more than quadrupling their range from 1985-1995.
Ecological damage caused by invasive species
The largest threat to native wildlife is loss of habitat. The two most common (and destructive) types of habitat loss are due to development and invasive species.
Weeds are destroying wildlife habitat and forage. Wildlife needs a variety of forage to thrive. Because of aggressive growing habits, invasive weeds often out compete native plants, replacing plant diversity with monocultures.
Weeds are damaging endangered species and native plants. Two-thirds of all Federally-listed species, and many native plants, are threatened by weeds.
Aquatic weeds can cover the surface of bodies of water, removing sunlight and oxygen that aquatic organisms need to survive.
Invasive animal species like burros feed on native tree species such as mesquite and paloverde. These trees host numerous insects that serve as a prey base for native birds and bats. As the burros strip these trees of foliage, insect numbers and diversity declines, as well as the species that feed off the insects. Burros also directly compete with the native Desert bighorn sheep for water and food resources.
Economic damage caused by invasive species
Land values may drop to as little
as 10% of their original value when lands become heavily infested with invasive
plants.
Economic impacts of leafy spurge on grazing and wildlands in Montana, North
and South Dakota, and Wyoming are approximately $129 million.
How is Havasu National Wildlife Refuge managing invasive species?
