More variability was found in the carbohydrate composition, particularly 

 non-reducing sugars, of rhizomes than the other plant parts. Most 

 of the carbohydrates in S^. alterni flora were found in the non-reducing 

 sugar fraction; therefore, this fraction was largely responsible for 

 the variability in the total sugar component of the tissues. Storage 

 carbohydrates were found in small amounts only in the rhizomes and 

 floral parts. 



Differences in carbohydrate composition were observed in all parts 

 of the short and tall forms of S^. alterniflora both within and between 

 the marshes. Seasonal patterns in carbohydrate composition were related 

 to phenophase events in vegetative growth, reproduction, and senescence 

 in the life cycle of S^. alterniflora . The development of ecophenal 

 extremes in the two height forms in the two marshes also influenced 

 the annual patterns in carbohydrate composition. Differences in the 

 initiation and duration of the primary period of growth at the two 

 marshes due to differential environments also had an effect on the 

 seasonal carbohydrate patterns. (A. A.) 



Keywords: primary productivity, Spartina , coastal marsh. North Carolina 



II-B-24 



Mendelssohn, I. A., and K.L. Marcellus. 1976. Angiosperm production of 



three Virginia marshes in various salinity and soil nutrient regimes. 



Chesapeake Science 17:15-23. 



The net aerial angiosperm productivity, salinity, and soil nutrient 

 composition of three Virginia marshes were determined. Oligohaline 

 Ware Creek Marsh and mesohaline Carter Creek Marsh were most productive, 

 while euhaline Wachapreague Marsh was least productive. Species in 

 Carter and Ware Creek Marshes were clustered into associations based 

 on salinity tolerance. Nitrogen and phosphorus concentrations of 

 Spartina alterniflora tissue were high in the spring and decreased 

 as the growing season continued. Soil nutrient concentrations were 

 variable, and trends during the growing season were not discernible. 

 No significant correlations were found between soil and plant nutrient 

 concentrations. Although the empirical data suggest that high soil 

 salinity and low soil nitrogen and phosphorus concentrations limited 

 primary productivity in Wachapreague Marsh, a multiple regression of 

 standing crop on these parameters did not delineate any as the primary 

 factors limiting salt marsh production. 



While the majority of research has centered on the descriptive 

 ecology and productivity of salt marshes, studies investigating the 

 essential factors limiting salt marsh macrophytic production have 

 only recently been initiated. Some of the factors that most probably 



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