WHEN POLICY DRIVES MANAGEMENT: STRATEGIES TO ELIMINATE CAREX KOBOMUGI (ASIATIC SAND SEDGE), AN EXOTIC INVASIVE IN DUNES WITHIN FEDERAL AND STATE PARKS

Asiatic sand sedge, Carex kobomugi, was probably introduced to New Jersey about a century ago when shipwrecks released plants used to pack Oriental porcelain. The species now ranges from Massachusetts to North Carolina. Our research shows that Carex in New Jersey is propagating exponentially, with expansion rates of 300% at Island Beach State Park (IBSP) and nearly 800% at the Sandy Hook Unit of Gateway National Park (SHU). Management strategies available for use in each park are strongly governed by Federal and State statutes and regulations. In the State Park, managers are able to use the herbicide Roundup® to selectively reduce populations of this species. Reduction efforts have been under way since 1999. Prescribed strategies for Carex removal call for repeated herbicide applications. However this has only been carried out at one site, although a total of four sites have now been treated at least once. Consequently, reduction and elimination of this species in treated areas at IBSP have been minimally successful to date. As a Federal Park, SHU is more restricted in its management options, herbicide use being strongly discouraged. Thus, management efforts there so far have been limited to a failed attempt at physical removal using a backhoe and sifter. Planned management strategies for Carex in the Federal Park include: 1) use of volunteers to dig out small stands of Carex before they become well established, which will be particularly important in wilder areas of the Park that have high native species diversity; and 2) use of burial in larger stands, using available sand in test depths of 15, 30 and 45 cm. Such burial will stimulate Ammophila breviligulata growth while hopefully inhibiting Carex. For IBSP, we are encouraging the managers to actually follow the prescribed procedures that they themselves developed, in order to allow assessment of Roundup’s® true effectiveness for the management of this species.