three points for sampling were randomly selected within each height zone. 

 Sampling was done at low tide when possible. Soil solution salinity was 

 field-determined with a handheld refractometer. 



Table 26. Soil Texture and Percent Organic Matter of Tall and Short 

 Height Forms of S. alterniflora for Seven Locations 



Location 



Percent Sand 



Percent Silt 



Percent Clay 



Percent O.M. 





Tall* 



Short 



Tall 



Short 



Tall 



Short 



Tall 



Short 



Oregon Inlet 



97.3 



96.3 



0.6 



0.8 



2.1 



2.9 



0.1 



0.1 



Hatteras 



84.6 



71.6 



9.1 



20.5 



6.2 



7.9 



5.1 



10.8 



Village 



















Ocracoke 



92.7 



96.1 



3.7 



0.5 



3.6 



3.3 



0.7 



0.3 



North River 



54.9 



69.0 



30.3 



20.6 



14.8 



10.4 



1.6 



2.4 



Beaufort 



47.1 



52.4 



40.2 



34.4 



12.7 



13.2 



5.0 



6.0 



Swansboro 



86.4 



93.9 



6.2 



2.6 



7.4 



3.5 



1.1 



0.5 



Oak Island 



57.3 



57.7 



30.6 



30.3 



12.1 



11.9 



9.3 



6.5 



LSD O.OSt 



















Loc. x ht . zc 



ne 10 



.0 



' 



'.9 



3.1 



1 



.7 



Height zone 



tLeast significant difference 

 (Main effects are not presented because of significant 

 location by height zone interaction) 



Measurements on the grass included dry weight (dried at 70° Centigrade 

 in a forced-air oven) , number of stems and their height (the average of 

 five randomly selected stems in each 0.25-square meter plot). The dried 

 samples were chopped with a silage chopper, and subsamples were ground in j 

 Wiley mill in preparation for nutrient analyses of the plant tissue. 

 Determinations of the concentrations of nitrogen, phosphorus, potassium, 

 sodium, calcium, magnesium, sulfur, iron, zinc, manganese and copper were 

 made by the Department of Soil Science, Analytical Service Laboratory at 

 North Carolina State University. Soil samples of the upper 15 centimeters 

 were taken in each height zone at the time of the first plant sampling. 

 These samples were air dried, and screened, and the following determina- 

 tions were made by the Soil Testing Division of the North Carolina 

 Department of Agriculture using their routine methods: organic matter, 

 calcium, magnesium, phosphorus, potassium, sodium, CEC (cation exchange 

 capacity) and soluble salts. Soil texture was determined by the hydro- 

 meter method (Day, 1956) . 



Regression analysis was the statistical technique used to detect 

 relationships between nutrient levels in the soil, plant tissue, and 



106 



