productivity of the grass. The role of fertility of the substrate 

 material as it affected starting new marshes by artificial propagation 

 had not previously been investigated. 



The productivity of natural marshes varies greatly from one location 

 to another [Cooper, 1969) . There is also variation within a given loca- 

 tion with three distinct height zones (tall, medium, and short) generally 

 recognized (Teal, 1962; Adams, 1963: Cooper, 1969). In the past, attempts 

 were made to relate differences in productivity to such factors as genetic 

 differences, time of inundation, and salinity. The efforts to relate 

 productivity to nutrients in this study were divided into two phases. 

 The nutrient status of plants and soils was sampled in natural stands from 

 seven locations along the North Carolina coast, and related to yields 

 using regression analysis. The second phase measured growth response to 

 fertilizer applications. Plants in natural stands, transplants, and 

 seedlings were included. 



1. Nutrient Status of Natural Stands. 



a. Methods . Stands of S. alterniflora at seven locations along the 

 North Carolina coast were selected for sampling during the summer of 

 1970 (Fig. 54) . These stands are representative of variations in latitude, 

 in tidal range, and in type of substrate occurring along the North Carolina 

 coast. The Oregon Inlet, Hatteras Village and Ocracoke sites are similar 

 in their location on the sound side of barrier islands where the tide 

 range is 30 centimeters or less. Two important damper effects cause the 

 narrow tide range in estuaries north of Cape Lookout: (1) few inlets 

 through the barrier islands, and (2) a large expanse of water behind the 

 islands. Winds greatly influence the surface levels causing a greater 

 but irregular fluctuation. The Oregon Inlet and Ocracoke marshes are 

 young stands on sandy substrate low in organic matter. The Hatteras 

 Village marsh grows on a substrate containing 10 percent organic matter. 

 The North River marsh is also in a location of low tide, growing on sandy 

 substrate, and consists of a narrow fringe (about 20 meters wide) along 

 the shore. 



The Beaufort, Swansboro and Oak Island marshes are in areas of wide 

 tidal range and are more typical of the regularly flooded southeastern 

 tidal marshes described by Cooper (1969). South of Cape Lookout, inlets 

 are numerous and the estuaries are narrow allowing a greater tide range. 

 Texture of the substrate is quite variable between the locations (Tab. 26). 



Plant samples were taken from each location and each height zone 

 17 to 23 June, 5 to 17 August, and 30 September to 2 October. The dis- 

 tinctness of the height zones varied among the locations. The medium 

 height zone was a narrow transition zone which was barely discernable in 

 several locations. Consequently, only samples from the tall and short 

 height zones were included in the statistical analyses. The plant samples, 

 consisting of 0.25-square meter plots, were clipped at ground level from 

 each height zone. The sample plots were selected by establishing a 

 transect across and perpendicular to the height zones. From this line, 



104 



