II-B-40 



Valiela, I., J.M. Teal, and N.Y. Persson, 1976. Production and dynamics 



of experimentally enriched salt marsh vegetation: belowground biomass. 



Limnology and Oceanography 21:245-252. 



Root growth increased during the early growing season in Spartina 

 alterni flora salt marsh plots. While fertilization with nitrogenous 

 fertilizer did not affect initial growth, a marked decrease in root 

 biomass followed the spring peak, particularly where nutrient doses 

 were highest. A sharp reduction in roots occurred in enriched areas 

 covered by S^. patens , although, as with S^. alterni flora , aboveground 

 biomass increased. Roots disappeared during autumn leaving rhizomes 

 as the only part of the plants to overwinter. The maximum standing 

 crop for roots was 0-2 cm deep; for rhizomes 2-5 cm. Net annual 

 underground production was calculated from annual increments in 

 dead matter belowground. Total production, underground and above- 

 ground, exceeds that of any other marine vegetation, ranging from 3.900 

 to 6,600 g m"2yr"' in S_. alterni flora areas and 3,200 to 6,200 g m'^yr""! 

 in S^. patens areas. Fertilization increased production, particularly 

 aboveground where dead plant parts are subject to export. (A. A.) 



Keywords: productivity, saltmarsh plants, biomass, Spartina , nutrients, 

 U.S. Atlantic coast, Massachusetts 



C. Algae and Phytoplankton Productivity Studies 



II-C-1 



Pomeroy, L.R. 1959. Productivity of algae in salt marshes. Pages 88-96 

 in Proceedings of the salt marsh conference, Sapelo Island, Georgia. 

 University of Georgia, Athens. 



The surface layers of the sediments in salt marshes contain a diver- 

 sified population of algae. Pennate diatoms of many genera and species 

 are abundant. Dinoflagellates, green, and blue-green algae are also 

 present. Although the algal population of the marshes is inconspicuous, 

 and the standing crop is small, the rate of growth of the population is 

 rapid, and growth continues throughout the year. The amount of energy 

 transformed by algal photosynthesis is a significant contribution to 

 the total primary production of the salt-marsh ecosystem. 



Photosynthesis of the marsh algae was measured under bell jars filled 

 with filtered, boiled estuarine water (by change in oxygen content of 

 the water) and made at various elevations on the side of a natural 

 levee beside the Duplin River, a tidal drainage creek. These were 

 taken to represent production in other areas of the marsh having 

 similar elevation, density of Spartina , and temperature conditions. 



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