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

Though a large number of publications concerning the sand-strand vegetation and maritime forest of the eastern United States has been published, Oosting's (1954) excellent review summarized our knowledge of coastal ecology up to that time. Thus, this information need not be duplicated here. This book is confined principally to more recent developments, particularly those concerning North Carolina.

Just a year after Cowles' (1899) classic papers on sand-dune ecology at Lake Michigan, Kearney (1900) published a detailed account of the strand vegetation on Ocracoke Island. He presented a system for classifying strand vegetation, discussions of environmental parameters, and notes on the anatomy of some strand species. Johnson (1900) described briefly the flora in the vicinity of Beaufort and Lewis (1917) gave a comprehensive description of the vegetation on Shackleford Bank. Coker (1918) visited Smith Island and noted the northernmost limit of cabbage palmetto (Sabal palmetto).

Wells and Shunk (1937) recognized that the flag form of seaside shrubs and trees is due to the killing effect of wind-borne salt spray to the growing shoots. They (1938) further emphasized that the salt spray is the most important factor in determining the distinctive composition and succession of the dune community. Wells (1939) explained the live oak forest of Smith Island on the basis of tolerance to salt spray and called the forest the "salt spray climax."

By means of cheese-cloth traps, Oosting and Billings (1942) measured wind-borne salt spray on the dunes at Fort Macon and noticed the correlation between the intensity of salt spray and the zonation of dune grasses. This was checked experimentally by spraying potted plants of these grasses with sea water. No significant correlations could be detected with regard to soil moisture, soil temperature, soil pH, air temperature, relative humidity, evaporation, and soil salinity. Oosting (1945) further tested the tolerance of strand plants with artificial salt spray and observed again that they are relatively tolerant to salt spray. Boyce (1954) demonstrated clearly the source, the distribution, and the physiological effects of salt spray on some species. By that time, salt spray as the most effective factor for limiting the distribution of strand plants growing close to the ocean was well established and commonly accepted. However, it has not been demonstrated that salt spray is equally important in limiting the distribution of tree species in the maritime forest.

Engels, in the course of investigating the vertebrate fauna of Ocracoke Island (1942) and Shackleford Bank (1952), described briefly the vegetation of those two areas. He (1952) discussed the paths of hurricanes and their damaging aftermath on Shackleford Bank. Rondthaler (1952) also studied the vegetation and flora of Ocracoke Island. More recently, the vegetation and flora of the Outer Banks were described by Brown (1959). Bourdeau and Oosting (1959) carried out a phytosociological study of live oak forest in North Carolina with description and measurements of edaphic factors. Burk (1962) collected specimens extensively on the northern sections of the Outer Banks. The only comprehensive autecology of sea oats (Uniola paniculata) was studied by Wagner (1964), who investigated its life cycle and determined how the species is instrumental in the formation and maintenance of dunes.

Other papers dealing with the strand vegetation outside North Carolina but on the East Coast were published by Davis (1942), by Kurz (1942) and Laessle and Monk (1961) for Florida, by Martin (1959) for New Jersey, and by Egler (1942) for Cape Henry, Va. As a whole, more coastal studies have been done in North Carolina than in any other eastern state. Also, far more papers have been published concerning coastal vegetation on the East Coast than on the West Coast of the United States. Of the latter, the investigations of Olsson-Seffer (1908, 1909a, b), Ramaley (1918), and Purer (1936) are representative.

Early research on dune communities in Britain was carried out by Oliver (1912), Farrow (1919), Salisbury (1922, 1925), and Rempel (1936). After World War II, the dune community received much attention from British ecologists, notably Gimingham (1951), Robertson and Gimingham (1951), Salisbury (1952), Gillham (1953, 1957), Gorham (1958, 1961), Ranwell (1958, 1959, 1960), Willis et al. (1959a, b), Wilson (1960), Willis and Yemm (1961), Willis (1963, 1965), Scott (1965), and Etherington (1967). They commonly emphasized the important roles of edaphic factors and sand movement. Until recently, only one paper concerning the effects of salt spray on the vegetation in Britain has been published (Edwards and Holmes 1968), although the measurement of salt spray was reported by Edwards and Claxton (1964) and Rutter and Edwards (1968).

A large amount of research on dunes and maritime forest has been done by Japanese ecologists such as Numata et al. (1948), Numata and Nobuhara (1952), Tsuda (1961), Nobuhara et al. (1962), Nobuhara and Toyohara (1964), Saito et al. (1965), and Mitsudera et al. (1965). Their approaches generally followed those of American ecologists in attention paid to the damaging effects of salt spray and sand movement on the dune community.