Ammophilo 

 brevi I i gulota 



IM-, 



BARE 



S p a r t i n 6 



pa tana 



Spar tine 

 o It ©mi flora 



50 m 



100 



April 1972 (aftar ovcrwosh) 



August 1973 



Figure 28. Drift line dune development on a washover fan (after 

 Godfrey, Leatherussn, and Zaretaba, 1979). 



The derailed vegetation study conducted in 1977 increased the available 

 data on washover revegetation. Storms on 10 May and 10 June 1977 flooded 

 the developing dunes, killing many Amnophita bveviligulata plmts. Some new 

 tillers of Amrnophila bveviligulata had recolonlzed the site by the time the 

 area was sampled in August. 



Data from site 1 fan were divided into three sections: the adjacent 

 unaffected marsh, the periphery of the washover, and the center of the wash- 

 over fan (Figs. 29 and 30). Table 5 reviews the data for the adjacent marsh 

 area. This area was largely high marsh with a mixture of low marsh vegetation 

 at the bayward extremities of the plot. Spartina patene was the dominant 

 species, with an importance value (I.V.) of 209.80, indicating that most of 

 the site was within the high marsh community on Nauset Spit-Eastham. Spartina 

 alterniflora, Salicornia virginica (glasswort), Puccimllia sp. (alkaligrass) , 

 and Limonium nashii (sea lavender), in order of decreasing importance, were 

 the most common components of the low marsh community (Table 5). 



Tables 6 and 7 review vegetation data for the peripheral area and the 

 center of the washover fan, respectively. The peripheral area was located at 

 the edge of the fan where sand buri? 1 was shallow (<10 centimeters) 5 years 

 after overwash; some plants had grown through the deposit. Other plants 

 colonized this area by rhizome extensions from the adjacent marsh. Species 

 composition of the peripheral area reflected the adjacent marsh vegetation as 

 expected. A comparison of Tables 5 and 6 shows that the species composition 

 for the two areas was very similar. All six plants found In the peripheral 

 area were also found in the adjacent marsh. Only Distichlis spicata (spike 

 grass), a minor component of the adjacent marsh, was not present in the periph- 

 eral area. These data show that six species are either rhizomatous or capable 

 of withstanding major overwash deposition. Spartina patens, Spartina alterni- 

 flora, and Salicomia virginica are ihizomatous . Many marsh plants can with- 

 stand some siltation as a natural process occurring in tidal marshes. 



The vegetative composition of the center of the washover fan differed 

 greatly from the peripheral or adjacent marsh areas (Table 7). Comparisons of 

 the three areas by I.V. appear in Table 8. Amrnophila, which cannot withstand 

 saltwater inundation during the growing season, is a good indicator of supra- 

 tidal vegetation. The other seven species found on the washover fan are also 

 components of the sand-dune community in New England. Only Spartina patens 



64 



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