Number Pag*? 



30 Seasonal salt marsh inundation patterns 34 



31 Variation in soil density and soil carbon content with distance inland 



from the strean edge in a salt marsh in the Barataria basin 34 



32 Sedimentation rates on the Barataria saline marsh. (A) Mean seasonal 

 sedimentation 1975 - 78. (B) Mean seasonal sedimentation 



1975 - 79. Sedimentation rates were highest during the winters 



of 1975 - 78. Hurricane Bob and tropical storm Claudette 



passed through the area during the summer of 1979, resulting in 



very high deposition rates 34 



33 The decrease in free soil water salinity (mg/g) of chenier plain 



marshes with distance (km) from the gulf 36 



34 Concentrations of available Na, Ca, K, Mg, P, and N in different marsh 

 zones 37 



35 Vegetation zones in the Mississippi River delta marshes ■^g 



36 A deltaic plain brackish marsh. Note the "hummocky" appearance which 

 is typical of Spartina patens stands. The birds with black-tipped 



wi ngs are white pel icans , the smal ler ones ducks , mostly teal 40 



37 A diverse deltaic plain fresh marsh scene. Species are: Sagittaria 

 falcata (foreground), Typha sp. (right edge), mixed grasses and vines, 

 Myrica shrubs in rear 41 



38 Vegetation zonation in an intermediate marsh transition zone in the 

 Barataria basin. Factors arise from statistical clustering techniques 



and are identified by the dominant species 41 



39 Effects of substrate drainage conditions on the dry weight 

 accumulation by (A) Spartina alterni flora and 



(B) S^. cynosuroides 42 



40 A conceptual model of a typical wetland ecosystem, showing major 

 coTiponents and processes 44 



41 Monthly growth rates of Panicum hemitomon and Spartina alterniflora 45 



42 Seasonal changes in live and dead biomass of Phragmites austral is 



and Spartina patens during 1973 - 1975 47 



43 Production of intertidal S. alterniflora vs. mean tide range for 

 various Atlantic coastal marshes. Different symbols represent 



di f ferent data sources 49 



44 Variation in total aboveground biomass and height of Spartina 

 alterniflora with distance inland from the marsh edge in a Barataria 



basin sal t marsh 50 



45 Gulf-inland variations in live and total biomass in Spartina 



al terni flora marshes 50 



46 Effects of NaCl concentration in the root medium on the rate of Rb 



ix 



