Take a drive along N.C. Highway 12 in the
summertime, and it’s not unusual to spot tall and feathery stalks on
both sides of the road swaying with the breeze. On the oceanside, these
unmistakable plants that poke out above the sand dunes are the familiar
sea oats that line the beaches, but on the soundside, these similar
spindly plants are something else entirely.
Common reed, formally known as Phragmites, has
been an issue for the Cape Hatteras National Seashore for years. An
invasive plant species that has been around for centuries, this tall
and pliable reed has been overtaking large swaths of the area’s marshes
and soundside regions, elbowing out other native vegetation which used
to thrive in the local landscape.
It’s a problem that hasn’t gone unnoticed,
either. In 2012, the National Park Service (NPS) estimated that
approximately 800 acres of brackish-water marsh in the park was being
severely impacted by Phragmites, and in 2012 and 2013, the park began
and effort in cooperation with the NPS Southeastern Exotic Plant
Management team to begin treating patches of Phragmites to prevent a
continued spread into other areas of the National Seashore.
It’s a tough and uphill battle to address the
problem. This invasive exotic plant species is a prolific seed
producer, but typically spreads through vigorous growth of rhizomes and
stolons, which can grow roughly six feet per year. The perennial grass
is also reported to release the allelopathic chemical gallic acid into
the soil, which inhibits the establishment and growth of other marsh
species, dwindling the competition. As a result these combined
characteristics, Phragmites, once established, frequently develops
dense, monospecific colonies over extensive areas, and can overtake
shorter native marsh species. According to data from the NPS, isolated
patches of Phragmites can double in coverage every 5 years, which is
why steps are continually being taken to beat back new growth, and why
long-term plans are in the works for a more aggressive response.
The large and almost tropical looking swaths of
common reed are fairly easy to spot today, but as it turns out, they
have been a resident of coastal North Carolina for a very long time.
The common reed is able to grow on virtually every continent on the
globe, and genetic testing of the plant has shown that both native and
non-native varieties of the common reed exist in the U.S. It’s the
non-native, invasive species that’s overtaking the local marshes, and
many researchers believe that this brand of common reed arrived on our
shores in the 1700s or 1800s, likely while being stored in the hauls of
ships from Europe, where they originated.
And while they look relatively at home in the
local environment, and similar to the sea oats that are clustered on
the oceanside of the highway, their invasive nature tends to do more
harm than good.
“This is an invasive species that is known to
take over habitats and push out more native species,” says
Environmental Protection Specialist for the National Park Service,
Sabrina Henry. “It just becomes such a thick species, that it pushes
out the plant species that our native wildlife would traditionally be
Working with specialized NPS departments and
other organizations, the NPS has undergone a years-long effort to hand
treat the species on a semi-annual basis.
“This past winter, we had the Exotic Plant
Management team in Georgia come to [our area] in January to map and
treat some areas, and they also came back in June,” says Henry.
“Typically, spring and fall is ideally when we want to treat the
“When we do treatment, we hand treat it,” she
adds. “We cut the stalks, and put on herbicide to make sure it gets
absorbed. But it’s so thick, that we do have to come back year after
year to re-treat.”
But hand treatment is not the only solution being
considered for long-term management of the common reed. Henry reports
that the National Park Service is looking into future aerial spraying
options, which will address the problem on a much larger scale.
“First we need a more extensive mapping of where
we are seeing the species, and where it’s going,” she says. “But we’re
working on a project for [applying] aerial spray to larger infestation
While steps are taken towards more streamlined
responses to the common reed infestation, Henry reports that the NCDOT
is addressing the area close to the Bodie Island Lighthouse, which is
currently heavily affected by the invasion of Phragmites.
“NCDOT will be treating 100 acres near the Bodie
Island Lighthouse over next five years,” says Henry. “They have also
been hand-treating Phragmites along the boardwalk near the lighthouse.”
The problem lingers for sure, and even with the
semi-annual treatments, common reed is still a common sight along the
marshes and brackish terrain that is found along the soundside.
But the problem is not going unnoticed, and the response is likely to be heightened in the months and years to come.
“We recognize that we have a concern we need to
manage,” says Henry. “We know we have areas we need to do better on,
and it’s something we are definitely working towards.”