a AntmcphilQ br@vUlgtifg?a drift 



A 90-cm burial 



o 



oj- 



1 



0*— 



12 



19 25 



June 



25 



B 14 



August 



27 



10 19 

 July 



1979 



Figure 80. Comparison of uaxlmura leaf length of Ammophvta 

 br'eviligulata In five habitats. 



February 1978 storm, many bay drift lines established in March 1978 persisted, 

 although many other areas on Nauset Spit-Eastham were destroyed by storms. 

 New drift material was continually added at lower elevations to long-standing 

 drift lines and subsequently burled by windblown sand. This additional mate- 

 rial acted as a buffer against storm activity, which occasionally eroded the 

 outer edges of the drift line, leaving the initial core intact. 



The bay drift lines are also buffered in terms of vegetative composition. 

 Dune vegetation is killed by saltwater inundation during the early part of 

 the growing season. Salt-marsh vegetation is killed by either high levels of 

 burial or by continual low levels of burial. Because both du.ie and salt-marsh 

 vegetation are present in bay drift lines, either plant community, depending 

 on elevation, can becorae established from drift-line plants. Ammophila 

 br'eviligulata, commonly found in bay drift lines, can, with sufficient sand 

 supply, begin to build dunes. Spartina patens, also found in this habitat, 

 wllL eventually be outcompeted by Ammophila br'eviligulata which thrives with 

 burial. Without necessary dune-building sediment or with higher than normal 

 spring tides during the growing season, Ammophila bveviligulata is killed, 

 while Spartina patens flourishes. Bay drift lines can thus become either the 

 site of new salt marshes or dunes. The bay drift lines were the most common 

 features on Nauset Spit-Eastham washover fans. 



148 



