Number Page 



absorption by excised root tissue of S^. a1 terni flora 

 and D. spicata 51 



47 Metabolic conversions of pyruvic acid. This "key" intermediate in 

 metabolism can be converted to a variety of end products, depending on 



the organism and the electron acceptors available 52 



48 Marsh soil transfonnations that result from tidal flooding 53 



49 Seasonal changes in various physical, chemical, and biotic factors in 



a Barataria basin salt marsh 54 



50 Net epiphytic production on stens of Spartina a1 terni flora collected 

 at the water's edge and inland 1.5 m with the averages, extremes, and 

 fitted curve for the water's edge production superimposed 55 



51 Number of shore-line epiphytic diatans/cm culm surface area of 

 Spartina al terni f1 o ra. Results are pooled averages for four stations 



and height classes 55 



52 Disappearance of S^. patens litter from litter bags in the 

 Pontchartrain-Borgne basi n 58 



53 Decomposition rates (mg/g/day) of S^. al terni flora litter incubated 



in 2 -mm mesh bags in different locations 59 



54 Major pathways of organic energy flow in a Mississippi River deltaic 



salt marsh and associated water bodies 51 



55 Length class frequency of qulf menhaden captured in and near Lake 

 Pontchartrai n 52 



56 Density of vegetation, detritus, and consumers at the edge of the salt 



marsh 53 



57 Pelt production from marsh zones in coastal Louisiana 55 



53 Annual muskrat harvest from a 52,200-ha brackish Scirpus ol neyi marsh 



in the Mississippi Delta 55 



59 Ground plan of a typical muskrat house with underground runways and 

 surface trail s 55 



60 A muskrat "eat-out" in the brackish marsh in the Barataria basin. 



Note the high densi ty of muskrat houses 57 



61 Carbon dioxide flux measurements in a deltaic salt 



marsh communi ty 72 



62 Carbon budget of a Mississippi River deltaic salt marsh (see Table 29 

 for sources). Rates (g C/m^/yr) are from CO2 flux measurements, 



except numbers in parentheses, which are fran other sources 72 



63 A schematic outline of the redox zones in a submerged soil showing 

 some of the N transfonnations. The aerobic layer has been 



drawn thick for clarity. In reality it is seldom over 1-2 mm in 



flooded marshes 75 



X 



