 JUNE -AUG O DEC -FEB 

 A SEPT -NOV •MAR -MAY 



2.5 



Ash free dry weight 



3.0 



log river flow ( cfs) 



Figure 22. Regression analysis of the 

 relationship of microdetri tus to 

 Apalachicola River flow by season (totals 

 taken from station 7, surface) (after 

 Livingston 1981a). 



systems (Mattraw and Elder 

 include headwater inflow, 

 ground-water inflow, upland 

 atmospheric fallout, and 

 within the aguatic system 

 hvdrological characteristics 



1Q8?). These 



tributary and 



productivity, 



productivity 



itself. The 



of the river 



system influence both the type of detritus 

 produced and the guantity transported, 

 since the wetland distribution is 

 determined by patterns of flooding, and 

 the same flooding provides an energv input 

 as a transport medium. The Jim Woodruff 

 Dam removes practically all the 

 particulate matter from the Flint and 

 Chattahoochee drainages (Mattraw and Elder 

 1982), so the Chioola-Apalachicola wetland 

 area is the primary contributor of organic 

 detritus to the bay system.^ 



b. Coastal marshes . The primarv 

 nonforested area in the bay system 

 consists of freshwater and brackish 

 marshes in the Apalachicola delta just 

 above East Bay (Figure 19). In parts of 

 East Bay, marshes are dominated by 

 bullrushes ( Scirpus spp. ), cattails ( Typha 

 domingensis ) , and other freshwater species 

 such as sawgrass ( Cladium iamai cense ) . 

 Brackish-water species such as cordgrass 

 and needle rush are also found. The 



northeast section of St. Vincent Island 

 has a well-developed brackish-water marsh. 



Kruczynski (1978) and Kruczynski et 

 al. (l'578a, b) have analyzed the primary 

 production of tidal marshes dominated by 

 Juncus roemerianus in the St. Marks 

 National Wildlife Refuge .iust east of the 

 Apalachicola estuary. The authors 

 considered such marshes representative of 

 undeveloped wetlands in northwest Florida. 

 Aboveground production was measured in 

 each of three zones based on soil 

 characteristics, elevation, and species 

 assemblages. The high marsh areas were 

 located approximately 600 m (l,Qfi9 ft) 

 inland; middle marsh areas were located 

 approximately 240-360 m (787-1,181 ft) 

 from the bay; and low marsh areas were 

 placed 0-120 m (0-394 ft) from the bay. 

 Based on carbon-14 methods, the authors 

 found that total aboveground production of 

 a north Florida Juncus marsh is S.S t C 

 ha"l yr-1 (3.8 tons/acre/yr) (low marsh), 

 5.7 t C ha-1 yr-1 (2.5 tons/acre/yr) 

 (upper marsh), and 1.8 t C ha-1 yr-1 (0.8 

 tons/acre/yr) (high marsh). Using average 

 figures weighted by area for an 

 extrapolated estimate of marsh 

 productivity in the Apalachicola marshes 

 (Table 1), there is an estimated net 

 production of 37,714 t yr-1 (41,561 

 t/yr-1) in the Apalachicola estuary (East 

 Bay, Apalachicola Bay, St. Vincent Sound) 

 and 46,905 t yr-1 (51, 68^ tons/year) in 

 the entire bay system. 



A comparison of these figures with 

 those from other areas (Table 6) indicates 

 that production of Juncus and Spartina 

 systems along the northeast Gulf coast is 

 comparable to that in other marsh areas. 

 According to Kruczynski et al. (1978b), 

 Soartina decomposes faster than Juncus , so 

 nutrients from the former may be more 

 readily available to associated estuarine 

 systems. 



3.1.2. Autochthonous Sources 



a. Phytoplankton . Phytoplankton are 

 ubiguitous in rivers, estuaries, and 

 coastal systems. The phytoplankton 

 community represents an important part of 

 aguatic ecosystems both from the 

 stamtpoint of primary production and as a 

 key element in food webs. Diatoms are 

 dominant in the net phytoplankton taken in 



31 



