Table 9. Sand accumulation under beachgrass 

 and increase in crest elevation in 

 American beachgrass plots. 



Plot 

 No. 



Description 



Sand J 

 accumulation 



(mVm) 



Increase in ^ 

 crest elevation 



(m) 



1 

 3 

 5 



American beachgrass 

 (45- by 45-centlmeter 

 spacing) 



American beachgrass 

 (60- by 60-centimeter 

 spacing) 



American beachgrass 

 (90- by 90-centimeter 

 spacing) 



51.4 

 43.9 

 78.2 



1.8 

 1.6 

 2.0 



After seven growing seasons. 



the elongation of the spit which provided an almost limitless supply of sand 

 from the northern quadrant. Supporting this contention is the fact that twice 

 the amount of sand was accumulated by the beachgrass in the northern half 

 (profile line 10) of plot 5 as compared to the southern half (profile line 9), 

 100.1 versus 56.3 cubic meters per meter. Sand accumulation in the southern 

 half of plot 5 was very similar to that in plot 1 (51.4 cubic meters per 

 meter). From this experiment, there is no evidence to support that close (45 

 by 45 centimeters) or wide (90 by 90 centimeters) spacing measurably influ- 

 enced dune growth. Zak (1967) also concluded that 90-centimeter spacing was 

 adequate except in areas of severe erosion. 



2. Comparison of Sand Fence Schemes. 



Table 10 summarizes sand accumulation and increase in crest elevation in 

 the spur (plot 2) and straight (plot 4) fence sections. 



Table 



10, Sand accumulation 

 elevation in spur 



and increase in crest 

 and straight fence plots. 



Plot 

 No. 



Description 



Time 

 interval 



Sand 

 accumulation 



Increase In 

 crest elevation 







(mo) 



(mVm) 



(m) 



2 



Sand fence with 

 side spurs 



8 

 (Jan. 1971) 



11.3 



0.9 







18 

 (Oct. 1971) 



17.5 



1.2 







90 

 (Nov. 1977) 



32.5 



1.8 



A 



Sand fence 

 with straight 

 sections 



8 

 (Jan. 1971) 



18 

 (Oct. 1971) 



12.5 

 21.3 



1.1 

 1.3 







90 

 (Nov. 1977) 



45.0 



3.0 



30 



