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Recognizing Carex
How it got here
Why it must die!


wpe3.jpg (18818 bytes)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 and again in 2008 and 2009, 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 2003 and doubled again between 2003 and 2008, with 48 acres now affected by the species at that Park.  At Sandy Hook things are even more severe, with an increase of 780% between 1985 and 2003 and a further 300% increase in affected areas between 2003 and 2008, with more than 54 acres of dunes in this park now being affected.  What this means is that more than 20% of the total primary and secondary dune areas of these parks is now occupied by this invasive sedge rather than native species.

 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, above). 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). 

As a result, we are now strongly of the opinion that management of this species to remove it from affected areas and to prevent its invasion of new areas is urgently needed in New Jersey.  To learn more about exactly why we think this, we are sharing the introduction to a recent grant proposal submitted to NOAA for consideration for funding for a major restoration effort in New Jersey's dunes.

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 does need to be carried out with 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

Read more about what we've found so far:
bullet 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.
bulletWootton, LS. 2003.  Spread rate and changes in species diversity associated with the introduced Asiatic sand sedge, Carex kobomugi, in New Jersey coastal dune communities.  5-page Extended Abstract.  Coastal Zone 2003 Conference Proceedings.
bulletMcGough A, Bevaart K, Ondreika J, Patel P, Wootton L.  2003.  Effectiveness of low-impact management strategies for eradication of Carex kobomugi (Asian sand sedge) from dune communities within New Jersey’s coastal parks.  5-page Extended Abstract. In Press for Coastal Zone 2003 Conference Proceedings.
bulletWootton, LS. 2002.  Chance Conversation Plants the Seed for NJ Sea Grant Research Project. The Jersey Shoreline.  Winter 2002. pp. 12-14.  (Reprinted in the Spring 2003 Court Pride as “Space Invaders: Hunting for Aliens on New Jersey’s Coastal Dunes")

Literature Cited

wpe7.jpg (9296 bytes)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 June 17, 2009

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