World sea level is estimated to be rising at more than 

 10 cm per century (about 4 inches) (Milliman and Emery 1968, 

 Bloom 1978). Relative sea level rise in the Albemarle region 

 has been estimated at 6 to 18 inches per century (Bellis et al. 

 1975), implying regional subsidence of the land. Data from Oaks 

 and DuBar (1974) give an average relative rise of 10 inches per 

 century over the past 725 years. 



These recent fluctuations, 10 feet in all, have left visible 

 reminders, and may be important in interpreting recent vegetation 

 changes. During the +4 feet high stand of the sea 1185 years ago, 

 a considerable additional depth of peat must have been deposited. 

 Now, however, the peat surface is approximately at sea level, with 

 small hummocks of vegetation raised a few inches above the surface, 

 interspersed with the general low flats, which are constantly 

 moist and flooded almost daily by wind tides. 



This illustrates well the dynamic nature of peat formation 

 and destruction at the interface between water and air. 

 Apparently all of the peat formed during the high stand of the 

 sea was oxidized during the following 500 years of sea level 

 recession. In the intervening 725 years between that time and the 

 present, peat formation has kept pace with sea level rise, creating 

 an average of 10 inches new peat per century. 



Evidence of recent sea level rise abounds along the shoreline 

 of Chowan Swamp. Numerous cypress and tupelo are found growing in 

 permanent standing water two feet deep, a situation in which they 

 could never have germinated today. Both species require at least 

 temporarily exposed soil on which to become established. Neither 

 could they have germinated in time of drought, since the area is 

 at sea level today. In the summers of 1980 and 1981, after a 

 severe drought, there was no readily observable change in water 

 level in the area being discussed. The only observed consequence 

 of the drought was the unusual sighting of blue crabs following 

 intrusion of brackish water, because of the lack of fresh water 

 flow from upstream. This influx caused dieback of a previously 

 lush growth of freshwater plants along the shores of the 

 Perquimans River near its mouth on the Albemarle Sound (observed 

 fall, 1981). In a year of normal rainfall, chloride content of 

 water in the Chowan River at the landing near the mouth of Sarem 

 Creek was ilmg/L, less than that of drinking water from wells 

 in the area (31 September 1979). Conductivity, also tested at that 

 time was only 70 micromhos/cm; pH was 6.7. 



VEGETATION DYNAMICS 



As water level rises, the swamp as a whole is moving upslope 

 over higher ground. This means that some low-lying areas such as 

 the pas tur eland along the upland swamp boundary near Gatesville 

 will become increasingly hydric. Juncus and other hydrophytes are 

 common there now. Along the Chowan the swamp forest appears to be 



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