MARSHLANDS MARAUDERS

Tall, feathery phragmites disrupt the natural mix of wet lands

Newsday, 10-21-2002, pp A39

By Madeline Bodin

Jane Moscowitch snipped a shoulder-high phragmites down to knee height. She crouched and dripped a few drops of purple-dyed herbicide into its hollow stem.

"Funny," she said, "I got my degree in environmental science one year, and the next year I got my herbicide applicator's license."

In July, Moscowitch, a conservation assistant with the Vermont field office of the global Nature Conservancy, was applying herbicide to protect an unusual ecosystem, a New England riverside seep, from Phragmites australis, the common reed, which is notorious for dominating the wetlands it invades.

As is typical in New England, ankle-high plants are naturally abundant in this seep, where few other plants can survive the high calcium content of the water or the annual scouring of ice from the White River, rushing over rocks just steps away. The changing seasons find the riverbank dotted with pink, purple and white from their tiny flowers. Rare rushes and sedges, both grasslike plants, also find a home here.

But one grass, the common reed, is not welcome. This invasive plant, which often grows to 6 feet tall, and sometimes to 15 feet, is found in wetlands around the world, from roadside ditches to salt marshes. Its feathery flower and imposing height make it as recognizable as it is common.

Unwelcome as they are, phragmites, as conservationists call it, has taken root in this Nature Conservancy preserve in the towns of Sharon and Pomfret, Vt. It threatens to shade the rare community of plants out of existence and leave the seep with all the rich biological diversity of a manicured lawn.

But the conservancy's Vermont office is far from alone in facing the phragmites threat. Land managers of every type, from the federal government to private homeowners, are looking for ways to eliminate, or at least reduce, the grip this plant has on their land.

The Montezuma National Wildlife Refuge in the Finger Lakes region upstate also has a phragmites problem, a huge one. It is home to hundreds of acres of the stuff. Phragmites forms dense, single-species stands that change the nature of the refuge's freshwater marshes, explained Tracy Gingrich, a refuge biologist.

"We're worried about marsh-dependent species, birds and mammals, " he said. These animals include muskrats, which find the cattails they rely on crowded out by phragmites; black terns, which are on the New York State endangered species list, and the least bittern and pied-billed grebe, birds on the state's threatened species list that rely on a mix of marsh vegetation and open water that is destroyed when phragmites takes over.

Phragmites hasn't always been a troublemaker. Phragmites fossils 40,000 years old have been found in the southwestern United States, and fragments of phragmites 3,000 years old have been found in Connecticut, proving that this plant is a native. Early American botanists described it as an uncommon marsh plant. By the early 1900s, however, botanists were describing phragmites, whose roots, called rhizomes, spread underground, as common.

Had pollution and development allowed a native species to suddenly stake a big claim in the continent's marshes, or had a non-native type slipped onto the scene unnoticed? Conservationists have battled the plant for decades now, but it is only in the past year that the mystery of how this once uncommon wetland plant was transformed into a wetland scourge has been solved.

Kristin Saltonstall, a doctoral researcher at Yale University last winter, reported in February she had discovered that a non-native strain of the invader was to blame and has spread along the Atlantic coastline. The introduced phragmites is the same species as, and looks like, the native strains but is genetically and ecologically different.

In her study Saltonstall analyzed DNA material from modern phragmites plants collected from all over the world and compared it with historical specimens preserved in herbarium collections, which provided a genetic snapshot of the plant on this continent before 1910. She identified 11 genetic types unique to North America and widely distributed across the continent before 1910.

Another genetic type, which she called "M," was found before 1910 in only four locations in North America, all on the East Coast. Current samples show it is now the most common genetic type in North America, and in Europe and Asia as well. The type M phragmites plants have replaced the native types in most of the northeastern United States, have pushed into the Southeast where phragmites historically did not grow, are expanding in the West and becoming more common in the Midwest, Saltonstall found.

She believes the aggressive type M was introduced to North America in the early 19th century at a port on the Atlantic Coast, because type M phragmites plants have so thoroughly replaced the natives there.

Today native strains are found on the Atlantic Coast at only two sites, one in Allen, Md., and the other in Chance, Va. Native types are much more common in the Midwest and West, in places like Minnesota, Indiana and Arizona. In spite of diligent searching, no native types have been found on Long Island, in New Jersey or in Connecticut.

A native strain has been found in Montezuma National Wildlife Refuge, however. Native and introduced phragmites grow side by side in the refuge, in view from the deck of the visitors center. Invasive plant expert Bernd Blossey of Cornell University, who has been serving as a consultant on phragmites removal strategies at the refuge, found the native type there.

Building on Saltonstall's genetic identification of the introduced phragmites, Blossey created a checklist of 15 traits that offer a remarkably accurate profile in determining whether a particular phragmites plant is native or introduced.

For example, native types have stems that are smooth and shiny, easily bent and reddish at the bottom in spring and summer. Their flowers are sparse, and the plants don't grow close to each other. The introduced type has stems that are rough and ridged, stiff when bent and tan at the bottom. Their flowers are full, and the plants grow densely.

The discovery of the native gene types has made Blossey's job - he specializes in the biological control of invasive plants - much more difficult, but his work on phragmites is particularly welcome because, once established, the plants are so difficult to eliminate. Few land managers are as lucky as The Nature Conservancy in Vermont, which discovered its phragmites problem when the plants were still sprouts, thanks to the sharp eyes of Sara Hand, a volunteer preserve steward.

At the Montezuma refuge, attempts in the late 1980s and early 1990s to mow down and dig up the clumps of phragmites did little good. Then in 1997 the refuge began using a two-step procedure: aerial spraying of the herbicide glyphosate (sold as Roundup) followed the next year by a prescribed burn to remove the dead plants and clear the soil for native seeds. Hundreds of acres were successfully treated, but in 2000 the funding for the program ended, said refuge biologist Gingrich.

Herbicide is a last resort for him, both because of the cost (about $100 per acre, he estimated) and the public's resistance to it.

He'd like to have a biological control, similar to the beetle Blossey discovered that devours purple loosestrife, another invasive wetland plant. Rose Paul, stewardship director of The Nature Conservancy in Vermont, is also eager for some way to control phragmites that isn't equally toxic to the rare plants that grow among the reeds in the Vermont riverside seep.

But they will both have to wait. Blossey has found some moths and flies that look promising for the control of phragmites. These insects have a gluttonous appetite for the stems or rhizomes of phragmites and cause enough damage to slow or stop the spread of the plant.

However, the insects must now also prove themselves harmless to the native types, which on the Atlantic Coast, at least, are rare enough to warrant conservation themselves.

In the meantime, Gingrich will continue to search for funds to help make Montezuma National Wildlife Refuge more hospitable to the muskrats, terns, bitterns and grebes. The Nature Conservancy in Vermont will continue to apply glyphosate drop by drop in its riverside seep preserve to defeat the phragmites while safeguarding the rare plants nearby. And the invasive genetic type M will continue to spread to new areas, unmasked as a non-native wetland invader.

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