flow of organic matter and energy flow are presented in diagram, 

 as well as in the text. (B.W.) 



Keywords: salt marshes, primary productivity, Spartina alterni flora , 

 marsh fauna 



II-B-8 



Payonk, P.I. 1975. The response of three species of marsh macrophytes 



to artificial enrichment at Dulac, Louisiana. M.S. Thesis. Louisiana 



State University, Baton Rouge, Louisiana. 121 pp. 



Populations of three species of macrophytic vegetation in a fresh- 

 water marsh near Dulac, Louisiana, were treated between April 1974 

 and January 1975 with wastewater from a menhaden processing plant. 

 The wastewater significantly increased the net aboveground primary 

 production of Sagittaria falcata , Scirpus validus , and Spartina 

 patens . Production for S. falcata was 918 g m-'^yr"' for the experi- 

 mental population as compared to 608 g m"^yr"^ for the control (a 

 51 percent increase); similar data for S. validus were 1804 g m-2yr"' 

 compared to 1260 g m-^yr"' (a 43 percent increase). Data for S. patens 

 were 2939 g m-2yr"^ compared to 2128 g m"2yr"^ (a 38 percent increase) . 



Differences between the experimental and control mean content of 

 nitrogen and phosphorus in the plant tissues were used to estimate the 

 proportion of applied nutrients actually incorporated into the plant 

 tissues. S. falcata incorporated 4.6 percent of the nitrogen and 

 4.0 percent of the phosphorus applied to the plant tissues. S. validus 

 incorporated 3.4 percent of the nitrogen and 4.0 percent of the 

 phosphorus. S. patens incorporated 4.1 percent and 7.4 percent of the 

 waste nitrogen and phosphorus, respectively. 



Concentrations of nitrogen and phosphorus in the marsh surface 

 water were increased by the additions of the wastewater. Measured 

 increases in nitrogen and phosphorus concentrations accounted for 

 12 percent and 16 percent, respectively, of these nutrients added 

 through wastewater enrichment. The remainder of the added nutrients 

 probably was deposited into the marsh soil system or escaped from the 

 area through limited flushing action. (A. A.) 



Keywords: marsh plants, macrophytes, freshwater marsh, nutrients, 

 productivity, Louisiana 



II-B-9 



Eleuterius, L.N. 1972. The marshes of Mississippi. Castanea 37:153-168. 



Mississippi has a shorter coastline than any other state bordering 



the Gulf of Mexico. In the past few years, the marshes have come under 



38 



