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Weed control: Invasive species threaten biodiversity
By Alma Gaul

Oh, what a pretty plant!

Well, maybe not.

If you are standing in a Midwest forest and find yourself surrounded by a white-blooming plant called garlic mustard or in a Western streambed surrounded by pink-blooming salt cedar, the attractive quality of the blooms is canceled by the threat these plants pose to the environment.

Garlic mustard and salt cedar are two non-native, invasive species that decrease biodiversity because they crowd out native plants and, ultimately, the wildlife that depends on native plants for food and shelter.

In some respects, invasive plants destroy natural areas just as surely as if those areas had been bulldozed, only in a different way. It is estimated that more than $34 million is spent every year to control invasives, and the costs continue to grow.

Q: Why should I care?

A: When biodiversity suffers, ecosystems become unstable and the balance of nature on which all species depend suffers.

Q: What is an invasive species?

A: Plants that spread from human settings (gardens or farms) into the wild. Once in the wild, they continue to reproduce, displacing native species.

Q: How do these plants get into the wild?

A: Sometimes the seeds are dropped by birds that have eaten berries; sometimes they are windblown. They also are transported by people. The key point is that while a plant may be very mannerly and non-invasive in your flower bed, it may act altogether different — like a thug — in the wild.

Q: This seems to be a huge problem; are there groups working on this?

A: Yes, quite a few. The North American Weed Management Association, based in Meade, Kan., is a network of public and private professional weed managers involved in implementing noxious weed laws.

Often, local communities form their own groups (Community Weed Management Areas, or CWMAs) to set priorities and coordinate efforts in a given area.

Q: What can I do to help?

A: Don’t plant materials in your yard that have become invasive in your area. Just because a plant is for sale at your local garden center — or widely used — does not mean it is safe. In the Midwest, for example, the winged euonymous, or burning bush, is a very popular, widely sold shrub. But its seeds are carried by birds to woods where it often becomes a big problem.

• If you have an invasive species in your yard, consider removing it.



• Instead of planting “exotic” plants that came from other countries, plant those native to your area. The added bonus is that these plants usually are easier to maintain — they need less water, for example — because they are adapted to your climate’s normal conditions.



• Find out whether there are local groups that organize eradication efforts in parks and preserves and volunteer to help pull or cut down these plants.



• Find out whether your area has a Community Weed Management Area and see whether the group needs any help.



• Avoid transporting seeds of invasives into natural areas. If you are a boater, clean your boat and equipment thoroughly before transporting it from one site to another. If you are a hiker, clean the weed seeds out of your socks and shoes between trips.



• Many people still do not know the damage that can be caused by invasive species. Spread the word.

Alma Gaul is a reporter for the Quad-City Times in Davenport, Iowa, agaul@qctimes.com.