Gearing Up For The Fight
As invasives continue their march, Cynthia Boettner has a daunting job. Boettner is part of a team whose task is to protect the biodiversity of the Silvio O. Conte National Fish and Wildlife Refuge, which encompasses 7.2 million acres in four states along the Connecticut River, most of it privately owned. Many of these landowners are not be actively involved and invasives are abundant. Resources, however, are finite.
The team picks their fights. “Rather than trying to battle those species that are already widespread, knowing that it’s so labor intensive and costly, we’re putting a lot of effort towards a few species we can actually keep from becoming problems,” she says. At the top of the list is water chestnut, a plant that forms a thick canopy over slow-moving water as it grows, and, among other problems, blocks the sunlight from submerged plants.
In this war, land managers also need to choose their method of warfare. They can pull by hand or machine, use herbicides, or attempt biological control. For Boettner, most of the time, getting volunteers to jump in a canoe and go out pulling water chestnut is effective. “It’s easy to grab a hold of and pull out, and because it’s large you can see progress quickly,” she says. “And this particular species is an annual, so if you can prevent that plant from producing seeds it’s dead, and it doesn’t cause any problems the next year.” Indeed, the water chestnut problem in the Chesapeake Bay is under control thanks to similar ongoing work.
However, some plants, like Japanese knotweed, are extremely difficult to fully extricate from the ground. “You can cut it and remove it but ... the roots are deep and they spread really fast,” says Katie Holden, assistant administrator in the department of planning and land management for the town of Concord, Mass. “If you leave any, even a small fragment, then that would regenerate.” Also, ironically, pulling or cutting some plants, like the seemingly omnipresent purple loosestrife, when they are seeding can actually help spread the plant.
When an area is widely infested, herbicides can be an attractive control option. But herbicides may poison groundwater and frequently require permits to apply. So many land managers turn to biological controls. The idea behind these is to introduce a predator into the ecosystem to help keep the invasive in check. A great deal of study and research happens before any biological controls are attempted because of the potential unintended consequences of introducing yet another non-native species to fight an invasive. In the WMNF, rangers released small, leaf-eating galerucella beetles last year to feed on purple loosestrife. Though promising so far, it will be several years before definitive results are known.
Almost anything done to fight invasives in the WMNF has to first be permitted by the National Environmental Policy Act (NEPA). Mattrick is currently attempting to complete the lengthy approval process, in advance. “We are trying to get all of our known sites and any future sites that might occur on the forest permitted so that we can do rapid response,” he says. “That way we can go out and treat these things without having to go through the NEPA process every single time for every infestation.”
Homeland Security
Mattrick has found that it’s easy to get people to care about the influx of invasives-all it takes is a little education. And these are compelling stories. Hikers and canoeists who see their paths and streams overgrown to the point where they can’t even get past are readily convinced that invasives are a problem.
It’s the people who don’t spend much time in the outdoors who pose a bigger challenge. For these folks, Mattrick zeros in on the pocketbook. When invasives become a costly problem for timber companies, he tells them, that cost is reflected in the cost of lumber and other building materials; the same is true for farmers and ranchers, who pass along their expenses to their customers. Now that federal, state, and local governments understand the severity of the problem, they use tax dollars to try to control invasives-by some estimates, the total bill for economic damage and containment efforts is almost $140 billion per year. And “it all cascades down to the end consumer,” says Mattrick.
Getting people to care is one thing; helping them to take action to address the problem is another. Once you’ve acquired a working knowledge of local invasives, Bill Brumback, conservation director at the New England Wildflower Society, says it’s extremely helpful to remove any from your yard to prevent them from jumping to other areas-particularly if you live near an ecologically preserved area. Not planting invasives in the first place is also helpful; in fact, the state of New Hampshire is in the process of restricting some of the plants nurseries are allowed to sell, including Norway maple and Japanese barberry.
Anyone planning on making a trip to a place struggling with invasives (like the WMNF) should thoroughly clean their boots, equipment, and car before leaving home. Really. That way you won’t be bringing along the seeds of a new infestation-the very antithesis of the Leave-No-Trace trail ethic. Mattrick says the forest is now discouraging visitors from bringing their own firewood, as a way to limit the chances that invasive bugs and seeds will be delivered directly to campgrounds. “If you do bring it, burn it all. Don’t just leave it lying in the camp site,” he says.
For those looking to get more actively involved there are plenty of opportunities to get your hands dirty and help contain invasives (see sidebar). Because of the pervasiveness and threat posed by non-native species, many local land trusts seek volunteers to help pull purple loosestrife, honeysuckle, or water chestnut.
To Mattrick, the fight has become personal. “If we don’t do anything it can impact all the other things that I enjoy,” he says. “I’m going to have trouble with everything else I like to do outside, like gardening and hiking and biking and watching birds. Aside from my family-invasives are my number one priority.”
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 | | The Invasives | | |
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|  | Purple Loosestrife | Stunning purple loosestrife, which may have been imported as an ornamental plant in the 17th century, can rapidly overtake a riverbank. It grows extremely quickly in even the poorest soil and one plant can produce a million seeds a year. Most important, nothing can touch it: purple loosestrife has no predators in North America. |  | Garlic Mustard | Reaching more than three feet tall, this invasive - with white flowers and leaves that smell of garlic when crushed - monopolizes light, moisture, nutrients, soil, and space. |  | Japanese Knotwood | An elegant bamboo-like perennial imported as an ornamental garden addition, Japanese knotwood canes can shoot up to 16 feet high, topped by red-purple leaves. The sturdy and amazingly quick-growing plant has been known to push itself through house foundations. |  | Norway Maple | Attractive in spring and fall, the Norway maple is a favorite of home gardeners. But some states are attempting to bar nurseries from selling the tree as its snaking roots choke out surrounding plants. |  | Wooly Adelgid | Though it spends most of its life in a sack no bigger than the end of a Q-Tip, the hemlock wooly adelgid can destroy a mighty hemlock within five years. |
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--Chris Warren
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