KEENE VALLEY, N.Y. (AP) – Fat, red-speckled shoots of Japanese knotweed, like a forest of blood-spattered asparagus spears, emerge each April from a mound of dead canes to form a jungle of 10-foot-tall plants.

Their rhizomes spread underground 25 feet in all directions, sending up shoots tough enough to pop through pavement. If rhizomes reach a brook, bits break off and take root miles downstream. When rhizome-infested soil is hauled away by ditch-digging highway crews and later used to fill a washout, a new jungle will sprout there.

“This plant is the bane of my existence,” said Steve Flint, who heads an invasive plants control program for The Nature Conservancy. “It loves riparian corridors. It’s very resistant to herbicides. If you mow it, it spreads like wildfire because every chopped-up bit will grow into a new plant. It’s incredibly tough to eradicate it.”

From early June through mid-October, Flint virtually lives in the field, working to nip in the bud the alien species that threaten to overrun the Adirondack Park as they have other parts of the country.

“There’s very little budget and personnel for this work,” Flint said. “I’m like the Lone Ranger running all over the park, trying to find new infestations and get rid of them before they become a big problem.”

If invasive species are left unchecked, native plant life that’s part of the allure of the Adirondack wilderness could be lost. Multi-colored meadows of orange hawkweed, bluebells and black-eyed susans could give way to monotonous white stretches of garlic mustard or wild chervil. Boreal bogs could be choked by purple loosestrife and giant reed grass.

That has happened in prized natural areas elsewhere, as well as in much of the nation’s urban and rural landscape. Until recently, the Adirondacks had been spared incursion by invasive species, thanks to the rugged terrain, cold climate, and few highway corridors.

The invasion of alien species in the 6-million-acre Adirondack Park is still at an early enough stage that it’s possible to stem the tide with diligent management.

That’s the goal of the Adirondack Park Invasive Plant Program, a collaborative effort by The Nature Conservancy, the state departments of Environmental Conservation and Transportation, and the Adirondack Park Agency.

Topping the list of unwanted alien aquatic plants are Eurasian watermilfoil, water chestnut, and curlyleaf pondweed. Targeted terrestrial invaders include purple loosestrife, Japanese knotweed, common reed grass, and garlic mustard.

Japanese knotweed is typical of invasive alien species, in that it has no natural predators to keep it in check and aggressively crowds out native species. The 10-foot-tall plants have hollow stems, hand-sized, heart-shaped leaves, and long clusters of tiny white flowers. All that’s left in the fall are bare, bamboo-like canes, posing a brushfire hazard. Invasive species follow people into the Adirondacks; that’s why they’re concentrated along highway corridors.

Seeds and plant pieces hitch rides on vehicles and highway maintenance equipment and are trucked in along with fill soil for construction projects. The knotweed invasion was traced to a load of topsoil brought into Keene Valley 50 years ago.

On a recent morning, Flint attacked knotweed with pruning shears and a spray bottle of Roundup. Kneeling on a mound of old stalks resembling a beaver lodge, he cut down plants and spritzed a bit of herbicide into each hollow stump. He stuffed the plants into black trash bags, where they would cook down to slime in the sun before disposal in a landfill.

Flint enlists armies of helpers, including scout troops and Americorps volunteers. Herbicide use is kept to a minimum. Plants are yanked up by the roots if possible; otherwise, they’re cut down before flowering to prevent the spread of seeds.

The control plan includes teaching landowners and road crews to recognize invasive species and follow practices that minimize spread, such as washing mowers to remove seeds and avoiding reuse of infested soil unless it’s sterilized by baking in the sun under plastic.

A handbook was developed with descriptions of plants and control methods, along with detailed maps pinpointing locations of each species.

As Flint works to eradicate targeted plants, he keeps finding new invaders. One is wild chervil, which resembles Queen Anne’s lace. Another is black swallow-wort, a tenacious, twining vine in the milkweed family that’s also called dog-strangling vine. Flint found it in a preserve along Lake Champlain this spring.

“It’s of great concern because at the same spot is a globally rare plant called the ram’s head ladyslipper,” Flint said. “The swallow-wort could erase that pure stand of rare orchids.”

Other invaders threaten entire communities of more common plants.

One acidic bog in the northeastern Adirondacks has more than 180 species of native boreal plants on floating mats of vegetation, including carnivorous sundew, pitcher plants, rose pogonia and sheep laurel.

“It’s a very difficult place to get into to manage – a perfect environment for loosestrife to completely conquer,” Flint said. “We’re not just talking about displacing one or two endangered species; we’re talking about an entire ecosystem.”

But efforts are paying off. In 11 loosestrife hotspots along the St. Regis chain of lakes, volunteers have reduced the plant’s biomass by 50 percent in three years by pulling it up and removing seedheads, Flint said.

This is the third year of the invasive plant program in the Adirondacks. The next step, as alien species are eradicated, will be to replant native species in areas that were invaded.

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On the Net:

www.adkinvasives.com

AP-ES-07-31-04 1200EDT

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