The Jacksonville District and the City of Atlantic Beach are working to protect dune function, reduce coastal storm risk and strengthen shoreline resilience.
The city is partnering with the U.S. Army Corps of Engineers to eradicate beach vitex, an invasive plant species that threatens to displace native vegetation and could create long-term impacts along the coastline. The plant spreads through thick, horizontal runners that can produce new roots and woody stems at each node, making it difficult to control once established.
Jessica Spencer, a biologist with the district's Invasive Species Management Branch, led the early detection and rapid response effort to isolate and eliminate the population before it could spread through the dune system.
"The impacts of beach vitex involve its displacement of native dune vegetation. As the vitex spreads, it outcompetes native vegetation for the limited resources in the dunes and quickly forms a dense monoculture," said Spencer.
"Since this is a small, relatively isolated population, it was important to eliminate it before it had a chance to spread. Early detection and rapid response to this population have prevented it from spreading to the point that it would require long-term management in perpetuity."
Controlling beach vitex is more than vegetation management. When invasive plants replace native dune vegetation, they can reduce a dune's ability to stabilize sand and make it more vulnerable during storm events. The eradication effort protects dunes, which are vital to the coastal system and reduce storm risk. Native dune plants keep sand in place, fortifying the dunes to better withstand erosion.
"Managing invasive species in the dune system is critical with respect to providing native species such as sea oats and railroad vine the ability to flourish," said Atlantic Beach engineer Steve Swann. "This, in turn, provides excellent coastal habitat while reducing storm risk impacts to the city."
Beach vitex can also spread toward the beach, where its long, woody runners may interfere with sea turtle nesting and trap hatchlings as they move toward the ocean.
Before and After. Dense beach vitex and Piles of cut beach vitex, following a cut and spray herbicide treatment by the U.S. Army Corps of Engineers Jacksonville District. Photo courtesy of USACE
Federal agencies are required under executive order to take necessary steps to prevent the introduction and spread of an invasive species.
"Since this is a small, relatively isolated population, it was important to eliminate it before it had a chance to spread," Spencer said. "Also, since it was growing right along the edge of one of our CSRM projects, our future work in the area could have contributed to the spread of the plant."
Only 10 resprouts were identified during a July site visit. Recent visits also identified new seedlings that could be hand-pulled before they developed the runners that make beach vitex difficult to manage. Swann said the city has not found any additional areas of concern.
"It is encouraging to see that the only beach vitex plants that I had to control on this last site visit were seedlings that could be hand pulled," said Spencer. "Working with invasive species, it is rare to be able to eradicate a population. But catching a population early enough gives us that rare opportunity."
Since beach vitex has likely been established for years, leaving a seedbank in the soil, the site will be closely monitored. It may require several years without new plants appearing before the population can be considered eradicated.
Adjacent property owners are also encouraged to report any new plants to aid in the district's long-term management plan.
"This effort demonstrated that working together can result in a very efficient use of tax dollars to prevent a problem that could end up severely impacting the coastal dune system if left unchecked," said Swann.
For more information about the Jacksonville District, visit www.saj.usace.army.mil.
