Thirty-three billion dollars a year in damage to the economy! The destruction of natural habitats! Serious human health implications! Upon hearing these threats, the first thing that comes to mind is probably not plants! Yet invasive weeds have the potential to do all that and more. What exactly is an invasive species? While the term may conjure up images of menacing, flesh-eating Venus flytraps, an invasive species is simply one that is not indigenous to the area, but has the potential for aggressive growth. According to the United States National Arboretum, these pests often have an advantage over existing plants because insects and diseases in a new place may not affect them yet. Once they become well established in an area, the consequences can be significant, as this list from the U.S. Fish and Wildlife Service documents:
Damage Caused by Invasive Species
- Threaten ecosystems by dominating native plants which serve as nourishment and homes for wildlife. They are the second-greatest threat to endangered species after the loss of their habitat.
- Compete with crops and natural grasses in rangeland. They often have little nutritional value for livestock and some can even be harmful.
- Clog waterways and increase flooding. Maintenance costs for water systems and power plants can rise. Aquatic plants also usurp oxygen which suffocates fish.
- Become fire hazards . Scotch broom, pampasgrass and eucalyptus are highly flammable, and have higher fuel loads than native species, thus making wildfires more intense.
- Exacerbate drought. Saltcedar trees along Colorado River use 68 billion gallons of water annually.
- Host dangerous parasites. For example, buckthorn carries oat rust and Johnson grass host a virus that harms corn.
- Contribute to soil erosion if their roots are more shallow than native greenery.
- Decrease tourism – in some Colorado meadows, invasive plants are outcompeting native grasses and wildlflowers people come to photograph. In the Sonoran Desert, bufflegrass has the potential to eliminate 90 out of 100 native species.
- Can be harmful to human health. The Brazilian pepper tree allergen causes breathing problems and contact dermatitis. Making national news is the highly toxic giant hogweed found in the Northern U.S. When it comes in contact with skin, it can cause severe burns and even blindness. (Here is a video to help you identify this plant.)
The National Fish and Wildlife Foundation: Pulling Together Initiative
The purpose of this public-private partnership is to help communities keep invasive species in check by creating local weed management cooperatives. Partners can include horticulturalists, community groups and local governments. Priorities are given to:
- Projects that focus on a specific area, like a watershed, ecosystem or county
- Projects supported by private landowners, state and local governments, regional/state offices of federal agencies
- Projects where cooperatives can work together with various group to manage weeds in their jurisdiction
- Projects that have long-term weed management plans which use the principles of ecosystem management
- Include education and public outreach about the problem
Applying for Pull Together
Eligible applicants are Native American tribes, state and local governments, academic institutions, and consortia. Matching funds are required. Pre-proposals are due by July 12, 2017.
Editor's Note: This post was originally published on July 18, 2016 and recently updated to reflect the current deadline.
Invasive species vary by geographic area. A plant might mind its manners in one place, but become out of control in another. We compiled a list of websites so you can identify which invaders are of most concern in your state, and links to further resources to help in their abatement.