Louise Wootton, Georgian Court University

Asiatic sand sedge, Carex kobomugi,  was accidentally introduced to North America approximately a century ago and is now found along much of the Northeast coast of the United States. The species was initially propagated and deliberately planted as a dune stabilizer throughout the 1960s and 70s. However increased awareness of the potential damage caused by non-native plants in subsequent years has meant that the species had moved from being considered an endangered species (Fairbrothers and Hough 1973) to being listed as one of the ten most unwanted plant species in New Jersey (Robert Cartica, Natural Lands Management, NJDEP Pers. Comm.).   

During the summers of 2002 and 2003 Dr. Louise Wootton and her students mapped all existing stands of this species at Island Beach State Park (IBSP) and the Sandy Hook Unit of Gateway National Recreation Area (SHU). We are now hard at work surveying where and how much of this species is found on the coastal dunes elsewhere in New Jersey, and building a GIS database based on the results of these surveys.

Our research so far shows that the total area occupied by Carex kobomugi  at IBSP increased by about 300% between 1985 and 2002, and that at SHU by 780% over the same period. Combining our numbers with the published data from Shisler et al. (1987), Small (1954) and Stalter (1980) it is clear that the expansion rate of C. kobomugi in both of these areas has been approximately exponential (Figure 1). Our research also showed that this expansion is a potentially serious problem, since we found that abundances of native species were reduced by 50 to 75% within C. kobomugi  stands (Wootton et al. 2005). The species is also negatively impacting native species richness and species diversity, particularly in the more pristine areas studied (Wootton et al. 2005). 

While the current expansion of C. kobomugi   clearly has a negative ecological impact, the species is an important dune stabilizer, so its control or removal needs to be carried out with special care. Thus, when in 1999 IBSP started a removal project, they used highly localized applications of Roundup® so as to spare non-target plants, leaving them in place to hold the dunes. In 2002 and 2003 my students and I assessed the treated stands for remaining C. kobomugi  and for native plant abundances. We found that after 1 year of treatment, Roundup® applied in this way reduced, but did not eliminate, C. kobomugi.  Continued monitoring of dunes that have been treated in this way, as well as active pursuit of alternative management strategies are of great importance to our understanding of the best way to combat the ongoing expansion of this species.

Learn to identify Carex kobomugi

Click here to read our initial proposal for this project

Click here to see some pictures of us at work

Learn more about the Biology Department at Georgian Court University

Aronson J, Floret C, LeFloc’h E, Ovalle C, Pontanier R.  1993. Restoration and rehabilitation of degraded ecosystems in arid and semi-arid lands.  Restoration Ecology 1:8-17.

Fairbrothers DE and Hough MY.  1973.  Rare or endangered vascular plants of New Jersey. Department of Botany, Rutgers University, New Brunswick, NJ.

Shisler JK, Wargo RN, Jordan RA. 1987.  Evaluation of Japanese sedge, Carex kobomugi, for use in coastal dune planting and stabilization.  New Jersey Agriculture Experiment Station Publication number P-40502-03-87 

Small JA.  1954. Carex kobomugi at Island Beach, New Jersey.  Ecology 35:289-291.

Stalter R. 1980. Carex kobomugi Ohwi at Sandy Hook, New Jersey.  Bulletin of the Torrey Botanical Club 107:431-2.

Wiedemann AM, Pickart A. 1996. The Ammophila problem on the Northwest Coast of North America.  Landscape and Urban Planning 34: 287-99.

Wootton L, Halsey S, Bevaart K, McGough A, Ondreika J and Patel P. 2005. When Invasive Species Have Benefits as Well as Costs:  Managing Carex kobomugi (Asiatic sand sedge) in New Jersey’s Coastal Dunes.  Biological Invasions.  7:1017-27.

Author: Louise Wootton. Ph.D.  Last updated Aug 27, 2007