Invasive plants overtake natives

http://www.kentucky.com/latest_news/story/866538.html
Invasive plants overtake natives
By Andy Mead
amead@herald-leader.com
RED RIVER GORGE — Miscanthus sinensis is one of the worst offenders.

It takes advantage of our nourishing climate, and repays the kindness by smothering the locals.

The ornamental grass, which also goes by the alias Chinese silverplume, was planted at Natural Bridge State Resort Park in the 1930s, but it soon escaped and now is at large in the state.

It was one of the priority targets listed by the Forest Service last week when the agency asked for input on a proposed war on weeds in the Daniel Boone National Forest.

The 700,000-acre forest "is facing an ecological crisis," as native species are crowded out by the foreigners, the agency said.

The Forest Service plan calls for treating as many as 1,400 acres a year by various means, but actual numbers will depend on how much money is appropriated each year for the work. The proposal contains no cost estimates.

There have been efforts to combat invasive exotic plants in Lexington parks, at the Arboretum on Alumni Drive and in state parks and nature preserves. But the effort at Daniel Boone, which covers portions of 21 counties, has the potential to be the largest attempt so far to take back acreage for native species or at least stop the spread of exotics.

"Every acre lost to these invaders is a loss not only to our native plant species' diversity, but also displaces wildlife food sources and habitats," the Forest Service said.

More than 70 species are causing problems, the Forest Service said. Most of the offending weeds came here from Asia or Europe. They spread rapidly because they left behind whatever diseases or insects kept them in check back home.

The best-known invasive is kudzu. It can be found in the Boone, but it's not among the worst invaders.

The agency proposes to get rid of weeds by pulling, mowing, burning or spraying them with herbicides.

It issued a report asking for comments from the public. If the proposal is approved, work could begin next June.

The Forest Service says it wants to concentrate on areas, such as wetlands and cliff lines, where sensitive native species are found and invasives can do the most damage.

In some cases, the Forest Service says, it wants to work with landowners to remove invasives on private land that is adjacent to public land in the fragmented forest.

The two wilderness areas in the Daniel Boone — Clifty and Beaver Creek — are not included in the proposal, but the public is invited to give opinions on whether they should be.

Joyce Bender, president of the Kentucky Exotic Pest Plant Council, welcomed the move against invasives.

"I know they've had to go through a lot of processes to get to this point, so this is good," she said.

The Forest Service proposal uses what the agency calls "adaptive management, which allows it to react more quickly to new infestations. Bender said that is important, because "if they didn't give themselves the option to switch gears, they might not be as successful."

Bender also is a branch manager for the Kentucky State Nature Preserves Commission. She said she could not speak for that agency about the Forest Service proposal because she had not yet consulted with colleagues.

Jim Scheff, the director for the environmental group Kentucky Heartwood, said he was glad to see the Forest Service dealing with the invasives problem. But he said he is concerned about an over-reliance on herbicides to control the weeds.

"A site-specific, case-specific argument can be made for herbicides, but they should be a last resort," Scheff said.

He also said that when the Forest Service approves a logging road or a gas or oil well on the forest, it creates openings where invasive plants can move in.

"While they're looking at spending a lot of money and spraying a lot of herbicides to combat invasives, they're also engaging in practices that spread them," he said.

As part of a federal lawsuit that Heartwood is pursuing against the Forest Service, it argues that the agency hasn't considered the overall impacts of using herbicides. Scheff said he would like to see such an analysis as part of the invasive-plants effort.

David Taylor, the forest botanist for the Daniel Boone, said he expects comments from the public about herbicides.

"We know that is controversial for many people, but prepared properly, it is very effective," he said.

Taylor also acknowledged that logging and other resource extractions efforts can be an invitation to exotics.

"Our national direction is that we will do certain kinds of management," he said. "So we're trying to do a better job of mitigating after we do something."

Exotics can also come in when new trails are built, he said, or when a wind- or ice-storm knocks down trees.

"Many of these species like disturbances," Taylor said. "They follow disturbances."

To explain how ubiquitous exotics are in the national forest, Taylor walked along the Pinch-em-Tight trail head off Tunnel Ridge Road. Here's some of what he found in just a few yards:

■ On the edge of the parking lot was a large Elaeagnus umbellata, or autumn olive, that has small berries that are eaten and spread by birds. The autumn olive was often planted on reclaimed strip-mine land because it grows quickly, holds the soil and attracts wildlife. Now it's a nuisance.

"A lot of these plants that we consider weeds were brought in with good intentions," Taylor said.

Pointing to one of the many berries that were turning from green to red, he added that "because birds like them, every one of these is a potential new plant somewhere on this ridge."

■ Growing alongside the road was Microstegium vimineum, or Japanese stiltgrass.

It was first noticed 90 years ago near Knoxville, Tenn., and now is found through most of the eastern United States. It is so widespread that the Forest Service proposes to just keep it from spreading, not to reduce its numbers.

It isn't doing any real harm just growing along Tunnel Ridge Road, Taylor said. But seeds are washing into the woods and over cliffs, and the plant is moving into rock shelters that are a favorite spot of a native called white-haired goldenrod. That species is so rare that it is found only in the gorge and nowhere else in the world.

■ Rosa multiflora, or multiflora rose, was found. It was introduced to this country as a natural fence that also held soil.

"It made some pretty tough fences that kept cattle in place," Taylor said.

Now it's making thorny barriers in places it shouldn't be.

■ Miscanthus sinensis, the Chinese silverplume mentioned earlier, is an attractive plant that can be seen waving in the wind along the Mountain Parkway.

But with seeds that spread on the wind, it has overtaken thousands of acres, mostly in Eastern Kentucky. Many people plant it in their yards all over the state.

Besides pushing out native plants, the dried blades of grass from previous growing seasons pose a severe fire hazard, Taylor said. A small leaf-litter fire will hit a patch of the grass and become such an inferno that firefighters can only pull back and watch, he said.

"It's pretty and you can understand why people would want to plant it," Taylor said of the plant. "But it produces a lot of windblown seeds and if it gets a little ground, it goes."