rfl , - * -*■—■» ' -«*k- "i* •can 



. ' • ^* - - — 



,— : •-' A 



.'* 



\v ;; 



-t-- 



•?v - 





;4 fc*"*-"* 



A — -;/"--•-■» - ■ . * "~~ " 



Figure 85. bay drift lines on Nauset Spit-Eastham. 



established to the lee of the Nauset Spit-Eastham dune line. The deposits 

 are water sorted with fine material carried farthest by the incoming tide. 

 Individual bay drift deposits seldom exceed 10 centimeters in depth. Wind- 

 deposited sand between spring tides results in burial of these mats of debris. 

 In April 1978 additional drift material was laid over the lower edges of 

 the drift line resulting in alternating layers of organic material and sand. 

 Drift lines, initially about 50 centimeters wide, were occasionally expanded 

 to several meters with additional spring tides and wind-transported sand. 



Bay drift lines that were not adjacent to washovers were not b iried 

 between spring tides. Organic material that was not buried by sand was 

 unstable and could be moved by winds and tides. Drift lines that were not 

 buried by shallow aeolian sand deposits were not vegetated on Nauset Spit- 

 Eastham. 



Bay drift lines were widespread and densely vegetated in 1978. Many 

 seedlings were present as well as many regenerating fragments; 22 species of 

 flowering plants were present in Nauset Spit-Eastham bay drift lines (Table 

 29). Around Cape Cod, 34 species were located in 10 areas with bay drift 

 lines in 1978 and 1979 (Tables 33 and 34). 



(4) Comparison of Drift Lines . Not only did the species composition 

 of the three types of drift lines vary, but plant size and mortality also 

 differed. To determine the nature of these apparent differences, each of the 

 three types of drift lines was excavated in June 1978 and plant measurements 

 were taken. Examples of each type of drift line were chosen on Nauset Spit- 

 Eastham outside study areas (Fig. 86). Particular attention was given to 



139 



-A- 



