'Phrag': a bay wetlands mystery Reed: A tall plant called phragmites that grows densely around the bay is the target of a state herbicide campaign, but many questions remain about its ecological role.

On the Bay

July 26, 1996|By Tom Horton | Tom Horton,SUN STAFF

LEARN TO say it: Phragmites (frag-mighties) is the name of a tall reed that is becoming a fixture of Chesapeake wetlands.

Some would argue it's a scourge. Beginning this summer, a state program will pay landowners up to $60 an acre to spray the herbicide Rodeo in an anti-"phrag" campaign, even as large questions remain unanswered about the plant's behavior and ecological role in the bay region.

Most Marylanders have seen phrag along sandy Anne Arundel shores, by roadside ditches along U.S. 50 on Kent Island, in Eastern Neck and Blackwater national wildlife refuges, cloaking spoil banks along the C&D Canal and Baltimore Harbor.

Its feathery, plumey seed heads nod atop slender stalks with long, flat, narrow leaves. It can reach 22 feet in height, though 8 to 12 feet is more usual.

The plumes -- tannish through brown, purplish and white as spring proceeds to late autumn -- are lovely when they catch the early or late sun.

Phragmites grows so densely (the name derives from the Greek phragma, fencelike) that no other plant can compete. Where it occurs, phrag shows as a monocultural, darker green against the mix of other wetland varieties.

Phrag's popular reputation is as an "exotic," a nonnative plant of little or no wildlife value, an aggressive invader that, unchecked, will rapidly take over a diverse wetland.

The truth is not so simple, though there's little doubt control is needed in some places.

Mike Weir, the longtime Democratic state delegate from Essex and a driving force behind the new herbicide program, has watched phrag choke out whole Baltimore County marshes where he trapped as a boy.

More recently, phrag has expanded "like wildfire," he says, across a marshy Dorchester County hunting property he owns.

Spraying Rodeo, a Monsanto herbicide considered relatively nontoxic to wildlife and aquatic creatures, seems the only practical way to control significant acreages of phrag.

(Burning it or cutting it annually, covering it with black plastic or digging it up might work for a backyard patch).

The new program shares spraying costs 50-50, up to $108,000 a year. With safeguards for the safe use of chemicals and the restoration of wetlands, it seems to be more than just a weed-zapping boondoggle.

With a requirement that the phragmites occupies a minimum of 5 acres, the program seems designed to benefit waterfowling clubs and other large wetlands owners, rather than owners of small lots.

Meantime, we ought to begin fleshing out promptly a fuller picture of what is really going on with phragmites around the bay. How much should we worry about this latest "exotic invader," as a state news release recently called it?

Phrag actually is native to almost everywhere. It grows on every continent except Antarctica and is documented in marsh peats thousands of years old in North America.

In Europe, it is prized. The close relative of papyrus is valued for paper-making and harvested for thatched roofs that insulate superbly and last longer than any shingling except slate. The reed stabilizes the soil of canal and river banks where little else will take root.

Phragmites is also a great source of concern in Europe -- because it is declining. Some blame higher levels of nutrients in polluted rivers, which is odd because elevated nutrients are listed as a reason for phrag's spread here.

This is just one example of how important questions about the reed have not been answered. Maryland does not even know how many acres of phrag it has or how fast it is spreading here.

Phrag is declining in parts of the United States and stable in others. In some places around the bay, it seems to be a stable feature of the landscape, adding diversity rather than overwhelming the ecosystem.

And there is emerging evidence that the decay of its stems and leaves may be an excellent source of nutrition for aquatic life, just like other marsh detritus.

Still, phrag's spread clearly has turned some diverse marshes into monocultures. This seems to have begun in the past 25 to 40 years, although, again, evidence is anecdotal except for one doctoral thesis that documented it by comparing old and recent aerial photos.

A couple of facts underlie the mystery. The spread of phrag is virtually synonymous with disturbance and alteration of the landscape -- diking, burning and ditching marshes; throwing up dredge spoil on their edges; impounding tidal areas to create waterfowl ponds; and building roadways.

All of these we have done in abundance, and all can give phrag, a great opportunist and able colonizer, the opening it needs to spread by seed or root and out-compete all else. Any long-term phrag management certainly should minimize such alteration of the natural wetlands regimes.

There is suspicion that not all phrag around the bay is the same, that more aggressive European types, indistinguishable without genetic analysis, may have come in recent decades.

It is also possible that natural checks on its expansion may come into play eventually, as often happens with invasive species.

A final intriguing speculation: Phrag may be one of those plants able to capitalize on humankind's dramatic increase in carbon dioxide (which plants breathe) in the atmosphere in the past half century.

If phrag is a scourge, it may be a symptom of our own disturbing ways.

Pub Date: 7/26/96

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