CAPE LOOKOUT Vegetation and Ecological Processes on Shackleford Bank, North Carolina NPS Scientific Monograph No. 6

Shackleford Bank, located approximately at mid-point of the North Carolina coast (Fig. 1), is one small section of a chain of barrier islands (Price 1951) bordering the southeastern United States. These barrier islands or offshore sand bars, separated from the main land by shallow sounds and extending from Cape Henry, Va., to Bogue Inlet, N.C., are locally called Outer Banks.

Fig. 1. Outer Banks photographed from Apollo 9 showing the location of Shackleford Bank, with inserted index map from Fisher (1967).

Shackleford Bank is east-west oriented, almost 9 miles (14.5 km) long, 0.20-0.65 mile (0.3-1.0 km) in width, and has a total area of 2280 acres [923 hectares (ha)]. It is separated from Cape Lookout at its eastern end by Barden Inlet and from Bogue Banks at the western end by Beaufort Inlet and is bounded by Back Sound on the north and the Atlantic Ocean on the south.

The island has been relatively undisturbed by people during the last 60 years due to its geographical isolation. Two miles of water (Back Sound) separate the island from the nearest residential areas, Harkers Island and the town of Beaufort. All means of public transportation are lacking. The prevailing onshore wind and occasional hurricanes produce a unique and peculiarly insular vegetation. For as long as it retains its remoteness and wilderness, Shackleford Bank will provide ecologists with an extremely valuable location for continued study of maritime vegetation.

A half century ago the vegetation of Shackleford Bank was described in detail by Lewis (1917). Since then, except for a brief description of Engels (1952), no vegetational survey has been done, to say nothing about the inquiry of ecological processes on the island. Since the vegetation could have changed a great deal in the ensuing 50 years due to its unstable environment, a new appraisal of the vegetation and the flora seemed desirable. Moreover, since it is planned for Shackleford Bank to be a part of a National Seashore Recreation Area in the near future, it could be subject to extensive use by the public. Therefore, there is a pressing need for a comprehensive ecological survey before the possibility of an acute disturbance. Accordingly, the objectives of the present study are, first, to investigate the structure of the vegetation as well as the flora on the island; second, to measure several of the most important environmental factors; and, finally, to measure plant responses both in the field and by controlled experiments.

To provide a predevelopment record of Shackleford Bank, a detailed vegetation map was prepared with: (1) a classification of plant communities; (2) a list of vascular plants, bryophytes, and lichens collected on the island; and (3) a description of plant communities. To understand the environment-vegetation complex, the general climate of the area, the striking wind, and edaphic factors were investigated in detail. Also, plant response to drought stress, to salt water and salt spray, and to the nutrients in the substratum were investigated. Hopefully, we will gain a better ecological understanding of the island, one that will be useful in any land management plan. Furthermore, we may acquire some knowledge of how complex environmental factors operate together to define the characteristics of plant communities on the coast. Since the interaction of the various factors is exceedingly complex, this study can only draw attention to several of the principal environmental factors influencing maritime vegetation and thereby provide a basis for future studies.