the 1977 and 1978 sites. The similarity index (50.0) suggests that the areas 

 are quite similar. Site l-F-w-77, which first overwashed 5 years earlier, 

 contained 3pecies with higher l.V.s that developed after an overwash event 

 (Agropyron pungens and Spartina patens) . Otherwise, the species composition 

 is very faimiiic between 1977 and 1978. The effect of overwash on an area 

 that has recently overwashed is to maintain an early successional drift-line 

 community. 



(3) Salt-Marsh Communities. 



(a) Comparison 5. 



Site l-F-78 was subdivided in order to analyze 

 had recovered from shallow overwash burial. 



a salt-marsh community that 

 Using sampling data, salt-marsh species were found to recover from as much as 

 33 centimeters of overwash sand burial. The quadrats at site 1 fan receiving 

 less than 3A centimeters of sand deposition between summer 1977 and August 

 1978 were also analyzed. These 152 quadrats (site l-F-p-78) were compared 

 with the same quadrats sampled in 1977 (.Tables 20 and 21). A map of the loca- 

 tion of these quadrats appears as Figure 37. The area was dominated by Spar- 

 tina patens (I.V. = 192.3) in 1977. Cover information indicated that only 16 

 percent of the site was unvegetated in 1977. Mean elevation was increased by 

 17 centimeters between 1977 and 1978. Elevation range and standard deviation 

 were similar in both periods. Species richness was reduced from seven species 

 in 1977 to only two species in 1978. Saliaomia virginica, Puccinellia rravi- 

 tima (alkaligrass) , Distichlis spicata, and Li»*?nium nashii did not recover 

 from shallow overwash burial. The species diversity of the area remained 

 similar from 1977 (0.4784) to 1978 (0.4935), reflecting the high l.V.s of 

 Spartina patens and Spartina alt ermi flora for both years. Kruskal-Wallis 

 tests run on Spavtina patens, Spavtina altevniflora, and bare sand data 

 showed that cover and density for Spavtina patens were significantly reduced 

 (P < 0.01) between 1977 and 1978; cover for bare sand was significantly 

 increased (P < 0.01) between 1977 and 1978, but cover and density of Spavtina 

 altevniflora were not significantly changed between 1977 and 1978 (P > 0.05). 

 The percentage of covev of Spavtina altevniflora actually increased between 

 1977 (23 percent) and 1978 (28 percent). The similarity index comparing the 

 two sites is very high (81.6) because Spavtina patens and Spartina altevni- 

 flora were effectively able to recover from the shallow overwash burial (less 

 than 34 centimeters deep at this site). 



Table 20. 



Summary of data collected from 152 quadrat samples 

 at the site 1 fan section that supported salt- 

 marsh vegetation in 1977 and was buried by less 

 than 34 centimeters of washover sand, August 1977. 



Species' 



Fr 



*9 



lency 





Co< 



er 





tens 



ty 



I.v. ! 





P-t 



Relative 



Pet 



RMjiIv 



* 



Tot a 1 Re 



l«t 



lve 



Pigtichl is spu'if : 



1.1 





0.5 



0.1 





0.2 





75 



0. 



1 0.7 



LimonitJPf na&hii 



20.4 





S.J 



0.8 





0.8 





91 



0. 



1 9.2 



Puc^inc* 7 in rraritinn 



32.2 





13.1 



2.0 





2.2 





1.S79 



I. 



3 IS. 5 



Sal i? oi—i i.i irirginuKi 



42.8 





17.3 



3.5 





3.9 





i .040 



3. 



2 24.5 



.<?[>> irff. ii alternifio'w 



'■»>.*> 





22.1 



22.8 





25.4 





5 .07.' 



4. 



1 52.4 



"V-4* T ?{nil Mfrns 



«i.9 





33.6 



60.5 





67.5 





113,1-81 



91. 



3 192.3 



Suaeda nviti-va 



10. 5 





4.3 



0.1 





0.1 





30 



0. 



1 4.4 



lUre s 

 Drift 



77.0 

 9.2 



15.8 



0.2 



'[live 

 •I.V. 



Richness » 7. 

 te values calculated 1 rom lover 



82 



MS^a:s^iii^ 



./\. 



*y 



