Spartina alt erni flora is able to recover from 22 centimeters of overwash 

 burial. Like dune species, but unlike Spartina patens, plant recovery for 

 Spartina altemiflora is not correlated with burial depth. Individual plants 

 buried by 22 centimeters of sand recover to similar cover and density levels 

 as plants buried by less sand. The elevation range over which Spartina alter- 

 niflora was found decreased only from 28 centimeters in 1977 to 27 centimeters 

 in 1978. Mean elevation at which Spartina altemiflora occurred increased 9 

 centimeters. Preoverwash density and cover of Spartina altemiflora cannot be 

 used to predict postoverwash density and cover. Quadrats with high density 

 and cover did recover better than those with lower density and cover. 



As witn Spartina patens, both cover and density of Spartina. altemiflora 

 were highly negatively correlated with elevation in 1977. Spo.rtina altemi- 

 flora grew best at lower elevations over the range of elevations sampled on 

 Nauset Spit-Eastham. In 1978, again no relationship between cover or density 

 and elevation was discovered on analysis. A 27-centimeter elevation range 

 may not have presented enough variation for biomass differences in Spartina 

 altemiflora quadrats to be evident. 



Cover and density for Spartina altemiflora, as for all sampled species on 

 Nauset Spit-Eastham, were highly correlated in both 1977 and 1978. Regression 

 lines for 1977 and 1978 were highly significantly different indicating that 

 individual tiller size was larger in 1978 than in 1977. Spartina altemiflora 

 density was highly significantly reduced from 1977 to 1978 at site 1 fan, 

 while Spartina altemiflora cover for the entire site actually increased. 

 Spartina altemiflora, while unable to recover from the high burial depths 

 (up to 33 centimeters) from which Spartina patens can recover, appears to be 

 stimulated by sand burial. Spartina altemiflora, annually buried by sedi- 

 ments borne by the tides, has, through time, been urder selection pressure to 

 grow through these sediments (recorded a3 high as 20 centimeters per year; 

 Ranwell, 1975). 



Like Spartina patens, Spartina altemiflora recovered best in quadrats 

 that did not contain other plant species. Plant recovery can be determined by 

 elevation alone and not by presence or absence of competing species. A model 

 for Spartina altemiflora recovery in site 1 far. appears in Figure 77. 



(c) Discussion . Unlike the dune community, the salt-marsh study 

 areas offered only a limited range of possible marsh situations .affected by 

 overwash burial. A wide variety of salt-taarsh species and elevations was 

 considered when sites were initially selected on Nauset Spit-Eastham. All 

 three sites sampled on Nauset Spit-Eastham had well-developed salt marshes in 

 1977. Site 1, which had first overwashed in 1972, had large sections of pure 

 Spartina patens and Spartina alterniflo^KL. There was also a substantial marsh 

 area with a mixture of species (.Spartina patens, Spartiria altemiflora, Sali- 

 cornia virginiaa, Limonium nashii, Pucainellia mcm+Ltiira. , and Suaeda rraritima) 

 found near the interface between the high and low marsh. Site 2 was a highly 

 diversified salt marsh with very irregular topography created by mosquito 

 ditching. Two species (Juncus gerardi or black grass and Saliaornia europaea 

 or glasswort), not present in other sites, were present in site 2. Site 3 

 was also a unique area on Nauset Spit-Eastham with substantial populations of 

 Plantago maribima. 



117 



