The Green Scene

These days, you don’t need a phaser or a lightsaber to battle alien invaders. Armed only with gloves, herbicides and some guidance from groups like the Western North Carolina Alliance, local volunteers are laboriously uprooting tenacious bunches of exotic grass and other plants that have taken root in the region’s public lands. Without such efforts, invasive species—the various trees, shrubs, vines, grasses, ferns, insects and fungi brought here from afar—can quietly take over delicate ecosystems, threatening WNC’s exceptional biodiversity.

Slow going: This snail was photographed as part of an effort to inventory all of the estimated 100,000 species in the Great Smoky Mountains National Park. Invasive plants and pests are a threat to biodiversity. photo by charles wilder for discover life in america

Controlling these species has “risen to the top of agendas in both the national parks and national forests,” says Alliance ecologist Bob Gale. “Since [their] budgets have been cut continuously over the last decade or so by Congress, they have no real funding and very little staff time to be able to put toward invasive species,” he notes, “even though it’s one of their major problems.”

Because species like Japanese stilt grass or Oriental bittersweet don’t naturally occur here, the ecosystem places no controls on their growth. That imbalance gives them a competitive advantage, putting many native species at risk. The spread of the hemlock woolly adelgid, for example, has led to the loss of 80 to 90 percent of the hemlocks in Shenandoah National Park, says Gale. Uncharacteristically warm winters in recent years have allowed this exotic insect, which would otherwise die in the winter, to thrive in the Southeast.

To help address the problem, the Alliance, which has chapters throughout the mountain counties, is enlisting citizen volunteers, says Gale. This past summer, the group sponsored four such excursions, teaching participants how to identify the problem plants, record them on an inventory sheet, and remove them.

During one outing, volunteers removed some 2,000 stems of Chinese privet from the Great Smoky Mountains National Park. Another group tackled a colony of Japanese stilt grass in Sandy Bottom. “There are quite a number of species of rare salamanders and other reptiles in the area,” Gale explains. “When the Japanese stiltgrass takes over, it displaces the native species that these creatures have evolved with. So if we can get rid of it … it will allow the native, diverse species to re-establish.”

Biodiversity—the range of different species found within a healthy ecosystem—helps keep it in balance. And some native species are natural treasures not found anywhere else. Entomologist Becky Nichols, who works for the National Park Service, has spent many hours cataloging critters for the All Taxa Biodiversity Inventory, an ongoing effort to document every last one of the 100,000 species believed to inhabit the Great Smoky Mountains National Park.

Of the 15,000 species known to exist in the park, says Nichols, some 6,000 have been identified since the program began in 1998. “And 858 of those are new to science,” she reports. “They range from spiders and mites to algae, bacteria, soil invertebrates and a lot of insects, moths and beetles.” Among the new creatures named by their discoverers, notes Nichols, is Allopauropus cataloocheensis, a minuscule, soil-dwelling invertebrate first unearthed in the Cataloochee area of the park.

For Gale, the fact that the mountain region shelters such remarkable biodiversity makes protecting it even more important. Exotics, he says, are “everywhere,” and they can be spread via car tires, birds, floods or even the soles of hikers’ shoes. The trick is prioritizing the ones that pose the greatest threats to rare habitats or ecosystems. “The dream would be to see every scout club, every neighborhood group etc., going out and doing this, just the way they do river cleanups or litter pickups and things like that,” he adds.

On Saturday, Sept. 29—the 14th annual National Public Lands Day—the WNC Alliance and the Appalachian Trail Conservancy will lead a work day in Hot Springs to identify and remove the most threatening invasive plants along the French Broad River. Last year, 100,000 volunteers across the country participated in the national day of caretaking. For information on how to become involved, e-mail jjudkins@appalachiantrail.org.