increasingly flatter as reflected by the standard deviation of the 120 eleva- 

 tion points. In August 1978 the standard deviation was 40 centimeters; in 

 March 1979 the standard deviation was 24 centimeters. Low dunes, evident in 

 the location of drift; lines, developed as a result of differential deflation 

 of surrounding areas and not by sediment accumulation in the vicinity of 

 plants. A total of 660 cubic meters of sand was lost from site 1 fart between 

 August 1978 and March 1979 (Fig. 24). 



By August 1979 an additional 140 cubic meters had deflated from site 1 

 fan, principally in unvegetated locations. Drift lines were formed during the 

 late spring abutting low drift-line dunes established in 197b . These drift 

 lines were well vegetated in August 1979 and accounted for a larger stabilized 

 area. 



During the 18 months in which deflation at site 1 was studied, 1160 cubic 

 meters or 60 percent of the initial washover deposit was lost from the plot. 

 The greatest deflation was 75 centimeters, which was lost from the south side 

 of the area. The greatest accretion occurred at the northwest corner, which 

 was unaffected by storm sedimentation, where 32 centimeters of aeolian and 

 tide-borne sediment had accumulated. 



A small amount of sediment lost from washover fans was blown into the 

 surrounding salt marsh, forming low mounds around dense stands of Spavtina 

 patens (saltmeadow cordgrass) and Spartina alterniflora (salt-marsh cord- 

 grass). The vast majority of sediment deflated from washovers on Nauset Spit- 

 Eastham, however, was blown seaward by northwest and southwest winds. Lost 

 from the back barrier, about half of this sand was transported to the beach 

 and about half was trapped in remnant dunes. 



To determine the relative amount of sand that was added to the dune line 

 at the periphery of the site 1 washover fan, elevation transects were estab- 

 lished at 5-cneter intervals in the dunes to the north and south of site 1 

 throat. At each elevation station, a hole was excavated around Ammophila 

 bveviligulata tillers. Each spring the vertical rhizoses of Ammophila 

 bveviligulata extend through the sand deposited during the winter. The apical 

 meristem, which remains approximately 6 to 8 centimeters below the sand sur- 

 face, near the interface between wet and dry sand, produces many leaves along 

 a very short section of rhizome. This vertical section of rhizoES with many 

 nodes and internodes can be used to locate the relative position of a sand 

 surface that remained stable for several months (Olson, 1958; Disraeli, 1982). 



Using the morphology of Ammophila bveviligulata, dune-building rates were 

 determined in the area peripheral to site 1 throat. Seven traasects frosa thi6 

 area are shown in Figure 25. The greatest deposition occurred along these 

 transects in positions nearest the washover. Sediment was transported as far 

 as 150 meters from the back-dune edge and to an elevation more than 5 rasters. 

 Maximum deposition v?as 71 centimeters, 10 meters south of site I throat. 

 Approximately 1000 cubic meters of sand was deposited in the dunes to the 

 southeast of site 1 by the dominant northwest winds; 450 cubic meters 

 accumulated north of site 1. Baring this same period, approximately 2800 

 cubic meters of sand was deflated from the entire washover fan. Therefore, 

 approximately 52 percent of the sediment deflated from the fan accumulated in 

 peripheral dunes. 



56 



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