Table 3. 



Growth characteristics of American 

 beachgrass planting, plot 1 (45- 

 centimeter spacing), 1970-77. 



Parameter 



Time interval by 

 growing season 



Value 



Sand accumulation 



One 

 Two 2 

 Seven 



-2.5 m3/lin m 



or loss 



16.3 m3/lin m 





55.0 m3/lin m 



Increase In 3 



One 



0.1 m 



crest elevation 



Two 



0.5 m 





Seven 



1.8 m 



3 

 Dune slope 







Landward 



Seven 



1 on 9.5 



Seaward 



Seven 



1 on 15.6 



Base width 



Seven 



61 m 



^Volume calculated for area 23 meters landward and seaward of 

 plot centerline; average of profile lines 1 and 2. 



Volvime calculated for area 30.5 meters landward and seaward 

 of plot centerline; average of profile lines 1 and 2. 



^Average of profile lines 1 and 2. 

 2. Sand Fence with Side Spurs (Plot 2) . 



a. Installation, Damage, and Repair . A single, straight sand fence with 

 side spurs was constructed in plot 2 in April 1970. Additional lifts of fence 

 were constructed in January 1971 (second lift), April 1971 (third lift), and 

 January 1972 (fourth lift). In April 1972 after the fourth lift had filled 

 with sand, the plot was planted with American beachgrass on 60-centimeter 

 centers, three to five sprigs per hill. 



The first lift of fencing filled by December 1970, 8 months after instal- 

 lation. One year later washover damaged the southern 30 meters of fencing. 

 The area was again overwashed in February 1972 at which time the southern 53 

 meters of lifts one, two, and three were destroyed in several places. The 

 damaged fences were not repaired. By August the weakened southern section was 

 again overwashed, and the beachgrass planting survival was low. In the north- 

 ern half of the plot, however, plant survival was high. A remedial planting 

 in the northern section was made in April 1973. 



b. Short-Term Dune Growth. During the first 8 months, the first lift of 

 fencing accumulated 11.3 cubic meters per linear meter. After 1 year the 

 first two lifts (Fig. 11) had trapped 13.8 cubic meters and after 18 months 

 three lifts had trapped 17.5 cubic meters. Subsequent winter storms, however, 

 removed all accumulated material from the damaged southern section of the plot 

 and removed about 0.9 cubic meter from the northern half. Thirty months 

 (October 1972) after initial installation, an average of 21.3 cubic meters had 

 been trapped by the fences and newly planted (April 1972) beachgrasses. 



c. Long-Term Dune Growth . Figures 12 and 13 depict dune growth in plot 2 

 along profile lines 3 and 4 from 1970 to 1977. Note on these figures that a 

 well-developed dune ridge existed landward of this plot when the study was 

 initiated. Despite earlier damage to the southern section, by 1977 both 



