FIGURES (Continued) 



Number Page 



3-51 Hydrologic regions of East Bay 141 



3-52 Freshwater supply of East Bay: (A) mean (1964 to 1974) montlily rainfall surpluses 



(deficits); (B) monthly rainfall surplus (deficit) for a dry year; and (C) monthly 



rainfall surplus (deficit) for a wet year 147 



3-53 Water levels in East Bay Basin; (A) monthly variation in daily tidal range; (B) seasonal 



variation in mean water level; (C) long-term annual mean water level; and (D) typical 



tide record 148 



3-54 Mean, extreme low and extreme high saUnity (°/oo) in East Bay Basin 149 



4-1 Distribution of plant species along a south-to-north 80-km (50-mi) transect in south- 



eastern Louisiana. The distribufion and percentage coverage of each species along 



the transect is indicated by the length and width of the black bar 154 



4-2 Distribution of plant species for four area types along a south-to-north transect in 



Calcasieu Basin. The distribution and percentage coverage of each species along 



the transect is indicated by the length and widtli of the black bar 155 



4-3 Comparison of soil calcium and total salt concentrations within four marsh types 



in coastal Louisiana 156 



44 Water salinities (mean ± standard deviation) in five natural habitats in the Louisiana 



portion of the Chenier Plain 157 



4-5 A model of a typical wetland system, showing major components and processes 158 



4-6 Hypothetical relationship between frequency of inundation and organic export 



from wetlands 160 



4-7 A comparison of primary productivity for different kinds of ecosystems 161 



4-8 Relationship between soil density and growth of smooth cordgrass 161 



4-9 A model of^the marsh nitrogen (N) cycle showing the major stores of N and 



interrelated processes 162 



4-10 The inhibitive effect of salt on growth of saltmeadow cordgrass 163 



4-11 The seasonal flow of organic matter througli the food cham 164 



4-12 Estimated energy budgets of wetland habitats (the circle area is proportional to 



annual primary production in each habitat) 166 



4-13 The food value of marsh Utter as it decomposes. The protein concentration in- 

 creases with time as the Utter is fragmented and crude fiber is decomposed 167 



4-14 The microbial-detritus cycle for an estuary 167 



4-15 Important processes of the marsh-water interface 168 



4-16 Relationship of marsh plant growth and distance of plant from stream edge 169 



4-17 Relationship of macroinvertebrate biomass and distance of individuals from marsh- 

 water interface 169 



4-18 Length-frequency distribution of Gulf menhaden at marsh and lake stations in 



Lake Pontchartrain, Louisiana 170 



4-19 The relation of Louisiana and Florida inland shrimp landings to the area of marsh 



adjoining the estuary in which the shrimp were caught 171 



4-20 Distribution of salt marsli habitat in the Chenier Plain 173 



4-2 1 Distribution of brackish and intermediate marsh habitats m the Chenier Plain 177 



4-22 Distribution of fresh marsh habitat in the Chenier Plain 181 



4-23 Distribution of swamp forest habitat in the Chenier Plain 185 



4-24 LitterfaU in a bottomland hardwood forest and in a cypress-tupelo swamp 



forest in Barataria basin, Louisiana 186 



4-25 Distribution of impounded marsh habitat in the Chenier Plain 193 



4-26 Effect of different impoundment management practices on the composition 



of marsh vegetation 194 



4-27 Conceptual model of energy flow and interrelationships between the inland 



open water and the nearshore Gulf habitats of the Chenier Plain 195 



4-28 Estimated organic fluxes (kg/ha/yr) to aquatic habitats for Calcasieu Basin. The 



number at the source of each arrow is per hectare of that habitat. The number 

 at the point of the arrow is per hectare of the recipient habitat. Organic 

 material was assumed to be uniformly distributed in each habitat, although 



phenomena Uke the edge effect demonstrate that this is not true 198 



4-29 Sources of organic energy and its uses in inland open water and nearshore Gulf 



habitats 200 



4-30 Distribution, in g/m^ (dry wt), of major benthic groups from north shore to 



mid-lake to south shore of a small lake in southeastern Louisiana 201 



4-31 Monthly densities of benthic fauna from August 1972 to AprU 1973 in south- 

 August 1972 to April 1973 in southeastern Louisiana 201 



xi 



