Sullivan’s Island Maritime Forest
While other residential beach communities along the South Carolina coast scramble to keep erosional forces at bay, Sullivan’s Island has actually been accreting, or gaining more land as sediment becomes trapped by the Charleston jetties. That sand would typically feed islands further south, like Folly Beach, without the jetties disrupting the natural transfer of sediment by ocean currents.
Recognizing the gradual accumulation of what could be seen as new beachfront property, the Town worked with the Lowcountry Land Trust to place deed restrictions on the accreted land. These restrictions prohibit any development, but they do allow the Town to cut vegetation for purposes of anything from emergency access to providing ocean views.
This has left Sullivan’s Island in the unique position of determining how to manage their growing maritime forest most appropriately for its function as wildlife habitat and protective barrier against the major storms we’ve seen become stronger and more frequent each year, while also being sensitive to its residents who’s properties abut the forest.
In 2016, Town Council proposed a plan to create a 100-foot “transition zone,” broken into two bands that call for more aggressive cutting in the first 40 feet from property lines. The 2016 plan proposed:
- In the first band (0ft-40ft from property lines), all underbrush and shrubs, including myrtles will be removed. Trees less than 6 inches in diameter may be removed with a site plan used to identify, for possible preservation, small trees of desirable species that seldom reach 6” diameter at maturity: Hercules Club/Toothache Tree, Black Cherry, Yaupon, Red Bay.
- In the second band (40ft-100ft from property lines), all trees except those on the List of Non-Native Invasive Species will be allowed to remain; underbrush will be removed. In areas adjacent to Forested Areas: all shrubs, including myrtles, will be removed. In areas adjacent to Maritime Grassland and Maritime Shrubland: myrtles and other shrubs will be thinned to 25% of current coverage.
The 2016 plan was not implemented due to ongoing litigation. After an appeals court ruled that the Town could not be forced to cut down vegetation*, Council revived the issue and it was taken up by the Land Use and Natural Resources committee. The compromise that came out of these new discussions seeks to remove far more vegetation with significantly less consideration for native species that should be retained.
Under the new 2018 plan:
- In the first band (0ft-40ft), all understory, shrubs, cedars, pines, myrtles, invasive species and trees smaller than 6 inches in diameter will be removed.
- In the second band (40ft-100ft), all understory, shrubs, myrtles and trees smaller than 3 inches in diameter or 12 feet in height will be removed.
Maritime forests aren’t just important as habitat and food sources for wildlife, they are also examples of green infrastructure that can make our communities more resilient.
Native small trees, shrubs and understory are of particular importance to wildlife as well as the overall health of the maritime forest.
- Once cut, wax myrtles and other native plants will be less capable of outcompeting invasive species for space, sunlight and resources. Invasive species tend to grow more quickly than natives, providing a significant advantage once established.
- Invasive shrubs like Chinese privet, Japanese privet and Japanese honeysuckle don’t provide the same mutual benefits to other flora and fauna. Species like these are even linked to drastic reductions in bee populations, affecting both diversity of bee species and the number of individuals present.
- Once invasive species are present, they often spread through similar methods as native plants, like seed dispersal by birds. Removal of native plants that have historically acted as food sources not only means space for invasives to take hold, but expansion of their territory.
- For more information on the impact of native trees and shrubs to wildlife of the maritime forest, explore this literature from the South Carolina Department of Natural Resources.
A robust maritime forest offers significant protection to properties and infrastructure located on barrier islands.
- Barrier Islands are designed to do the job of protecting mainland ecosystems from hurricanes, storm surge and flooding. When we build structures on these islands, we are putting ourselves in the first line of defense against such destructive forces. By cutting back the maritime forest, we leave residents and their properties even more vulnerable to extreme weather and erosion.
- A recent article in the Post & Courier highlighted recent findings that native woody plants provide significantly more protection than both grassy marsh ecosystems and man-made erosion control structures, and do the best job of building soil to keep pace with sea-level rise.
- Another study, published in the scientific journal Aboriculture and Urban Forestry in 2007, found that wax myrtles were of the top nine tree species in the Southeastern coastal plan demonstrating high survival during hurricane-level windspeeds.
- Shrubs, understory and small trees absorb and retain floodwater through their roots and promote healthy soil for faster infiltration into the ground. As a bonus, contaminated runoff is less likely to end up in our waterways.
Ultimately, the growing maritime forest provides the most benefits to wildlife and people when managed primarily for invasive species, allowing native species to grow and flourish.
*The case is being appealed to the SC Supreme Court.