Asiatic sand sedge Carex kobomugi Ohwi is an invasive species that thrives within the sand dunes along the Mid Atlantic and North East coastal plain. It was first discovered in the United States in 1929, here in Island Beach State Park.
There are many pieces to a dune management program but two critically important parts are increasing plant diversity and keeping out the invasive Asiatic sand sedge Carex kobomugi Ohwi. A resource manager looks to increase the number of different plant species established in the dune. Ensuring that any singular species will not overly dominate the landscape allows the dune to be productive in its ability to be a protector from the ocean’s surges while providing suitable habitat for wildlife.
A monoculture, or dominance of a single species leaves the dune at risk to a plant die off. If a single species dominates the landscape and experiences high mortality due to disease or other environmental causes, the dune can become susceptible to erosion.
Once established, Asiatic sand sedge dominates the native plant community. It decreases plant diversity by spreading quickly, forming dense mats that make it difficult if not impossible for native plants to survive within. According to Plant Conservation Alliance dunes that are dominated by Asiatic sand sedge are also more vulnerable to wind blowouts and storm erosion. There is visible evidence on dunes dominated by Japanese sedge of fewer native plant species and individuals than on comparable dunes dominated by the native American beach grass.
Asiatic sand sedge has long resided in Island Beach State Park but ever since the ocean surged over the dunes during Super Storm Sandy it has reach critical levels. Where it was once just minor pest it has now truly become invasive. Most areas where sand was mechanically disturbed or distributed as part of the post Sandy clean up now show signs of colonization. New colonization can also be seen at the terminal edges of the storm surge within the newly deposited sand.
Shifting Sands is actively working on getting funding to help provide assistance to Island Beach State Park’s increasing problem with Asiatic sand sedge.