the species exclusive to the sound-side disturbed community were those 

 often associated with highly disturbed locations. This community was 

 once the site of military housing which was demolished and the site 

 bulldozed. Prior to the establishment of these buildings the site may 

 have been partly covered by sound-side shrub and partly by a wetlands 

 community. At the present time it appears to be almost an ecotone 

 between sound-side shrub and low dune grass, with the weedy component 

 relatively stable. As long as these species are not overtopped by 

 heavy shade-casting competitors they will remain important, M. 

 pensylvaniaa is beginning to slowly expand into this area (frequency 

 5.4 percent). 



The two shrub-dominated communities and to some extent the sound 

 side disturbed community are being enriched by nitrogen- fixing 

 bacteria on the nodules of legumes and on the roots of M. pensylvaniaa. 

 Several excavations revealed the presence of such nodes on M. 

 pensylvaniaa at Duck, supporting the results of Morris, et al. (1974). 



Growing behind the foredune, in front of, between, and immediately 

 behind the stands of M. pensylvaniaa which compose the oceanside shrub 

 community is the oceanside intershrub community. Figures 4 and 5 show 

 this community to be quite distinct. Of the 16 species included in 

 the sanqjles of this community, 4 were exclusive; however, the other 

 species occurred in 43.6 percent of the other communities. The 

 components of this commionity are not shade tolerant and the oceanside 

 shrub community seems to be expanding to its detriment. 



Two of the remaining six communities appear basically natural 

 while the other four are manmade. The low dune grass community resembles 

 the moderate drifting dune community of Brown (1959). The harsh 

 conditions of these exposed, unstable sand dunes result in either a 

 sparse plant community or no vegetation. There was no vegetation on 

 about 27 acres at Duck (Table 13). Eleven different species were 

 included in the samples of the community; however, the biomass was 

 only 15.2 grams per square meter (Table 7). The annual nature of 

 many of the low dune dominants suggests great variability in its extent 

 and productivity from year to year. 



As indicated by their names the planted American beachgrass and 

 the planted bitter panicum communities were artificially established 

 on the most heavily bombed part of the study area. Decontamination 

 and extensive preparation prior to planting greatly modified the area's 

 topography (personal communication, D, Woodaxd, 1974}, 



Though A. breviligulata has the highest biomass in the planted 

 American beachgrass community, T. pia^urea is the more widely distributed 

 species (Table 5) . The composition of this community, as shown by the 

 ordination, is not very unique. In fact, the planted American 

 beachgrass, planted bitter panicum, sandgrass-buttonweed, and low dune 

 grass communities are all phytosociologically similar. The major 



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