parallel to the beach with each treatment replicated twice by 14- by 

 70-meter plots. Within these 16-row plots, the center 4 rows were 

 spaced 0.46 meters apart, the 4 rows on either side of the center 4 

 rows were spaced 0.76 meters apart, and the outermost 2 rows on either 

 side were spaced 1.1 meters apart. In the spring of 1974, greenhouse- 

 grown seedlings of sea oats were planted 1.5 meters apart on the crest 

 of the dune in barren areas. 



The planting was sampled in October 1973 and 1974. The 14 

 experimental plots were sampled in 1973 in the same manner as those 

 at Duck except that saltmeadow cordgrass was also sampled. Eight 1- 

 square-meter quadrats were sampled in 1974 on the oceanside and 8 on 

 the sound side of the dune in each of the 14 plots. The plant species 

 present and the estimated combined cover were recorded for each 

 quadrat. The aboveground vegetation was clipped by species for 

 subsequent biomass determinations, and dried at 70° Celsius before 

 dry weight determinations for American beachgrass. Euphorbia 

 poly gon-i folia L. (seaside spurge), bitter panicum, saltmeadow cordgrass, 

 and sea oats. 



The planting was observed periodically and fertilized twice during 

 the first growing season at the rate of 56 kilograms of nitrogen per 

 hectare. Elevation surveys were conducted in June 1973, 1974, and 

 1975, by running two cross sections per plot with a level to determine 

 sand accumulation. The experimental area was also repaired in the 

 spring of 1974, by filling gaps with sand and replanting barren areas. 



III. RESULTS AND DISCUSSION 



1 . Duck Planting. 



a. 1973 . There was little growth in the April transplants by 

 June 1973 (Fig. 5). Although much of the sand was still bare of 

 vegetation in September 1973, surviving transplants of bitter panicum 

 were well established and the area was becoming stabilized (Fig. 7). 

 With the exception of plot 3, which was a mixed species treatment 

 consisting of bitter panicum plus Hatteras beachgrass, the number of 

 leaves, culms, and the cover was greater with bitter panicum than either 

 of the other two dune grasses in all plots of two- and three-species 

 treatments (Table 1) . Only bitter panicum yielded cover values of 

 more than 0.50 percent. American beachgrass and sea oats were 

 initially found in scattered clumps throughout the planting site 

 (Table 1). 



A count on selected plots indicated the number of living bitter 

 panicum plants was greater in rows where the entire plant had been 

 buried in a furrow than in rows established by the conventional upright 

 planting technique (Table 2) . Average percentages of living transplants 

 were 31 for Hatteras beachgrass, 62 for bitter panicum, and 16 for 

 sea oats. Although survival of bitter panicum was good, growth during 

 the first growing season was slow compared to the other experimental 



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