Table 12. 



Summary of data collected from 351 quadrats sampled 

 at site 3, August 1977 (preoverwash) . l 



Frequency 



Covar 



Species 



Limonium nashii 

 Plantago rnritirn 

 Puccinellia sp. 

 Saliaomia vi-»ginisa 

 Svartina altevniflova 

 Spavtina patens 



Pet 



Relative 



Pet 



Relative 



I.V." 



19.2 



7.9 



1.4 



1.3 



18.4 



15.8 



6.5 



2.6 



2.4 



18.4 



43.2 



17.7 



14.2 



12.9 



45.9 



74.8 



30.7 



25.6 



23.2 



80.9 



10.7 



4.4 



5.0 



4.5 



13.4 



80.3 



32.9 



61.4 



55.8 



133.1 



'Density not sampled. 



I.V.'s are adjusted sums of relative frequency and relative 

 cover. 



by overwash, Godfrey and Godfrey ( 1973) showed that southern barrier flat com- 

 munities dominated by Spartina patens are able to recover to initial biomass 

 levels within 1 year. Aerial photographic comparison was used to substantiate 

 these short-term field measurements. Godfrey and Godfrey (1973) suggested 

 that a southern barrier flat community is, in fact, an overwash subclimax 

 community — a community maintained by overwash pressures. Aerial photos and 

 field observations of plant communities to the lee of artificially maintained 

 Ammophilia dunes of Cape Hatteras supported the subclimax theory (Dolan, 

 Godfrey, and Odum, 1973). Vegetation not adapted to overwash burial (shrubs) 

 displaced the Spartina patens-dominated grassland community after overwash 

 pressure was removed. 



Hosier (1973), using a quadrat sampling technique before and after a small 

 overwash (<18 centimeters of sand deposition), shot-ad that overwash burial 

 reduced biomass, but maintained similar plant communities, provided the over- 

 all changes in elevation were not dramatic. Travis (1976), also using a 

 quadrat technique, showed that statistical differences in the . vegetat ion 

 1 year after overwash did not exist between the affected area and an adjacent 

 area that had not recently been overwashed but was subject to frequent 

 overwash activity. Elevation changes of 30 centimeters or greater lead to 

 increases in the water-table height and associated changes in the plant 

 community structure. More recently, using aerial photographic analysis, 

 Hosier and Cleary (1977) showed that a cyclic sequence of overwash community 

 types and physiographic features can be distinguished along some areas of the 

 North Carolina coast. 



b. Methodology . To determine plant community response to overwash burial 

 on a northeast barrier beach, two approaches were used. First, the three 

 sites sampled on Nauset Spit-Eastham in 1977 were divided into community types 

 and analyzed based on the range of overwash effects on each community caused 



73 



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