AS SEEN IN The Virginia Gazette, by Gazette writer, Cortney Langley
The Virginia Gazette
6:13 PM EDT, July 18, 2014
Phragmites choke out beneficial native plants
"So this is what a healthy freshwater tidal marsh should look like," said Tim Russell, lab technician with the College of William and Mary's Keck Environmental Lab, gesturing to a mix of wetland grasses in stretches near the mouth of Powhatan Creek.
Russell was in the prow of Craig Metcalfe's motorboat on a recent excursion looking for invasive grasses in tributaries of the James River. Metcalfe is a member of the Friends of Powhatan Creek Watershed and is active in river stewardship volunteer projects through the James River Association and the Chesapeake Bay Foundation. The group surveyed the creek below Metcalfe's Landfall at Jamestown home.
Where Russell expected to find nasty invasive grasses, instead he found a healthy mix of arrow arum, pickerelweed, cordgrass, wild rice, millet, giant bulrush, cattails, marsh hibiscus and more on Powhatan Creek.
The news wasn't so good on neighboring Mill Creek. Entering the creek mouth under the Colonial Parkway bridge, large stands of invasive phragmites australis immediately dominate the landscape, to the exclusion of almost any other flora.
For wetland ecologists, phragmites – pronounced "frag-might-ese" – is one of the most pernicious plants threatening area shorelines. It crowds out native grasses both by forming dense underground mats of roots up to three feet thick that strangle out less aggressive plants, and by shading them out in dense stands towering up to 12 feet in height.
"It definitely continues to grow," said Rick Myers, natural heritage stewardship manager with the Virginia Department of Conservation & Recreation. "It's been expanding its footprint in the state steadily over a long period of time, at least 50 years. Almost everybody living in a coastal area of Virginia knows what it is."
That has a ripple effect as foraging wildlife and birds lose the wild millet, rice and other seeds more diverse grasses provide, Russell noted.
There is a native phragmites that usually grows along with the invasive type, Russell said. They are almost identical and usually have to be sent to the lab to be distinguished from one another. Generally, ecologists just refer to the bullying type as phragmites.
The invading grass also increases the risk and intensity of wildfires, obstructs waterfront views, blocks drainage and irrigation ditches and increases mosquito breeding, according to the Virginia Department of Conservation & Recreation, which has been mapping the incidence of phragmites across the state. It's work includes a 2011 helicopter aerial survey of the York River.
Myers said the survey found almost 1,000 acres of it during that leg. Hampton Roads has not been mapped because the area is too densely populated for low-flying helicopters to survey 20 to 100 feet off the ground, but shoreline all throughout Hampton and Newport News is host to the plant, Myers said.
James City Senior Watershed Planner Mike Woolson has spotted phragmites on the James River at Kingsmill and Governor's Land as well as on the York River, he said. It is one of a number of invasive water and upland species with which county landowners do battle. In the Chickahominy River, an underwater species, hydrilla verticillata, fouls boat water intakes and propellers.
"It can be not only a nuisance, but it can have some economic impacts in the county," he said.
What to do about it
Woolson said that he expects to soon present the Ware Creek Watershed Management Plan to the Board of Supervisors. That document contains a proposal to deal with an upland invasive almost everyone recognizes: Kudzu. A program may include partnerships with environmental organizations that provide volunteers and funding for such projects, he said.
That's the type of program the James River Association conducts, said Christiana Tambone, lower river outreach coordinator. The organization has sponsored workshops promoting native plants and focusing on the removal of invasives near Richmond, she said.
"We have been gearing up to do a lot of invasive removal," she said. "We support more of the native species."
Native species help replace another, human-based invasive that Tambone spends a good amount of time battling. Landowners too frequently install rip-rap as a protection against shoreline erosion, she said. Grading and installing rock offers none of the natural shoreline protection, wildlife cover and habitat nor nutrient uptake from stormwater run-off that native plants do, she said.
There may be a nexus between the two, as phragmites often takes hold in disturbed shoreline areas, according to state researchers. Often times it is found near bridges and spreads from there up through waterways into ditches and neighborhoods. As sea level rises, phragmites is being found all over the state in areas where the soils are now consistently wet, Myers said.
Russell and Randy Chambers, director of the Keck Lab, have found some promise of controlling phragmites with a natural buffer on the upland side. Russell explained that a buffer takes up nitrogen from run-off before it gets to the phragmites, leaving the phragmites sickly and straggling. Myers said that's promising for rural areas, but worried that some urbanized areas don't have room for forested buffers.
One of the main goals of the state's mapping program is to educate landowners about phragmites so that they can recognize it and eradicate it when it first appears, before it establishes a stranglehold on an area, he said. The department is working on a national mapping application, iMapInvasives, that will provide information on where it can be found throughout most of the state.
Visit http://www.dcr.virginia.gov/natural_heritage/vaisc/species/phragmites.htm for more information.
Langley can be reached by email email@example.com or phone at 757-345-2346.
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