II-B-38 



Nixon, S.W., and C.A. Oviatt. 1973. Analysis of local variation in the 

 standing crop of Spartina alterni flora . Botanica Marina 16:103-109. 



Measurements of standing crop biomass and height of the tall form of 

 Spartina alterniflora on twelve Rhode Island salt marshes suggest 

 that the nutrients in municipal sewage inputs may increase growth of 

 the grass. Spartina biomass in the Providence River and upper 

 Narragansett Bay was 39 percent greater than in the lower Bay and 

 107 percent greater than in Block Island Sound. Height of the plants 

 increased 5 percent and 67 percent over those in the lower bay and 

 sound, respectively. Even with enhanced growth from eutrophication, 

 calculations show that treatment of marsh areas with sewage effluents 

 is not a realistic hope for the recycling of wastes from coastal 

 cities, or for providing low cost tertiary treatment. 



2 



The mean dry weight at the end of the growing season was 840 + 321 g/m 



for all marshes, with a range from 433 +80 g/m^ to 1380 + 220 g/m . 

 Grass height averaged 112 + 28 cm on all sites, with a range from 

 50 + 12 cm to 142 + 16 cm. Multiple regression analysis indicated that 

 concentrations of ammonia, sediment phosphorus, and sediment nitrogen 

 could account for 77 percent of the between site variation in Spartina 

 standing crop. Grass height was correlated with sediment iron in 

 a manner suggesting this element as a possible limiting factor. 



Half of the twelve marshes were significantly different from all 

 other sites in terms of grass height, demonstrating the importance 

 of having samples from a variety of marshes in each area when analyses 

 of large climatic gradients on production are attempted. (A. A.) 



Keywords: Spartina , biomass, salt marshes, mineral nutrition, productivity, 

 Rhode Island 



II-B-39 



Valiela, I., J.M. Teal, and W.J. Sass. 1975. Production and dynamics of 



salt marsh vegetation and the effects of experimental treatment with 



sewage sludge. Journal of Applied Ecology 12:973-981. 



Fertilization with a 10-6-4 sewage sludge fertilizer increased the 

 total peak standing crops of salt marsh vegetation, in spite of the 

 presence of considerable amounts of heavy metals and chlorinated 

 hydrocarbons in the sludge. Increases in standing crop were detected 

 in the second year of treatment and remained for three years of treatment. 

 The increases in biomass are believed to be due to the addition of 

 nitrogen. 



Spartina alterniflora , which was the dominant species in low marsh 

 areas, progressively excluded Salicornia spp. from the fertilized 

 plots after an initial increase of Salicornia. In high marsh 



63 



