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Invasive Plants Threaten National Landscapes

It’s summer again. People will be spending more time outdoors strolling through city parks, gardening in their yards or vacationing at any one of our country’s beautiful national preserves. However, what they may not realize as they take in the breathtaking natural landscapes is that these picturesque areas actually are in peril from a group of insidious predators—otherwise known as invasive weeds.
To most of us, weeds are merely pesky, little nuisances we try to keep at bay as we proudly display a lavish garden. But what people may not know is that when some weeds spread unchecked, they truly can have devastating and farreaching effects. More often than not, invasive weeds are exotic transplants from other nations that get out of control in the United States when separated from their natural predators.

“Invasive weeds are detrimental to our nation’s agriculture, water quality, wildlife and recreation,” says Jill Schroeder, Ph.D., Professor of Weed Science at New Mexico State University and President of the Weed Science Society of America. “Many people may not realize that weeds interfere with the production of our food, cultivation of feed for livestock and crops grown for textile production. Invasive weeds are considered biological pollution and it’s a real problem. In fact, the economic impact of weeds in the U.S. has been estimated at a staggering $34.7 billion annually, according to a Cornell University report.”

Each year, invasive plants claim another three million acres in the U.S. That’s an area about twice the size of Delaware. When they proliferate, they can choke out native plants, forever altering entire habitats as animals lose food, shelter and water to these persistent intruders. Currently, numbers of invasive plants are on the rise as increased land development disturbs previously untouched areas and global trade breaks natural barriers.

Sometimes, the introduction of an invasive plant species is done unknowingly when we add new or exotic plants to our yards or gardens. Some nurseries and national home improvement chains actually have stopped selling certain plants, such as Japanese barberry and burning bush. While quite attractive, these and other new or exotic plant species can take root in natural forests or preserves and become a problem to native plant species.

Invasive weeds also can wreak havoc in national parks. A barrage of leafy spurge threatens Theodore Roosevelt National Park in North Dakota; the seemingly insatiable melaleuca thrives by devouring acres of the Florida Everglades and it’s a constant battle to keep hydrilla from invading the Great Lakes.

The good news is that manual removal, along with responsible herbicide practices, are proven methods of invasive weed management. Projects that focus on eradicating harmful weeds and exotic plants are ongoing through local park districts, state university extension programs and national parks.

“Everyone has a part in helping expunge invasive plant species from our lands,” says Joe DiTomaso, Ph.D., Cooperative Extension Weed Specialist at the University of California, Davis and editor of Invasive Plant Science and Management Journal. “If we work together, we can restore millions of acres of natural landscapes. It also creates a wonderful opportunity to teach our children proper environmental stewardship.”

About the Weed Science Society of America:
The Weed Science Society of America, a nonprofit professional society, was founded in 1956 to encourage and promote the development of knowledge concerning weeds and their impact on the environment. The Weed Science Society of America promotes research, education and extension outreach activities related to weeds, provides science-based information to the public and policy makers, and fosters awareness of weeds and their impacts on managed and natural ecosystems. For more information, visit http://www.wssa.net.