take into consideration the timed in- 

 teractions of upland watersheds and 

 downstream dependent systems (Liv- 

 ingston and Loucks 1979). Indeed, 

 the biological significance of detri- 

 tus fluxing in such systems remains 

 in doubt (Haines 1979; Odum et al. 

 1979). 



The present study is part of a 

 comprehensive long-term program to 

 determine the functional relation- 

 ships of hydrology (Meeter et al. 

 1979), energy relationships (White 

 et al. 1979), food web character- 

 istics (Sheridan and Livingston, 

 1979), and the timed interactions of 

 river inflow and biological produc- 

 tivity (Livingston and Loucks 1979) 

 in the Apalachicola estuary. This 

 paper will address specific questions 

 related to the timing (seasonal, 

 annual) of net inflow of particulate 

 organic matter to the Apalachicola 

 Bay system. 



MATERIALS AND METHODS 



A monitoring program was estab- 

 lished to estimate short- and long- 

 term trends of river-derived detrital 

 input into the Apalachicola estuary. 

 Sampling stations were established 

 along the lower reaches of the river 

 (Figure 1: stations 7, 8). Surface 

 and bottom samples were taken at 

 station 7; mid-depth samples at sta- 

 tion 8. Once each month, from August 

 1975 to the present, water was pumped 

 through a series of sieves (mesh 

 size: 2.00, 1.00, 0.500, 0.250, 

 0.125, 0.090, 0.045 mm). All samples 

 were taken on a falling tide. The 

 amount of processed water depended on 

 local conditions and varied from 50 

 to 1000 liters. Detritus samples 

 were preserved in 2 percent HgCl„. 

 Details of the laboratory procedures 

 are given by Livingston et al. 

 (1976). Dry weight (dried at 100°C 

 for 24 hours) and ash-free dry weight 



(dried at 500°C for one hour) deter- 

 minations were made for each sample 

 (± 0.001 g) . All such samples are 

 referred to as microdetritus , and 

 only total values (i.e., all sieves) 

 were used for this study. 



A qualitative estimate of the 

 identifiable particulate matter in 

 the estuary (macrodetritus) was made 

 by analyzing monthly trawl tow sam- 

 ples (32 replicate 2-minute tows 

 with a 5-m otter trawl at 11 perma- 

 nent stations; Figure 1) from Janu- 

 ary, 1975, to the present. Samples 

 were preserved in the field with 10 

 percent buffered formalin. In the 

 laboratory, the detrital samples 

 were identified according to origin 

 (macrophyte or tree species, where 

 possible), dried (100°C for 24 

 hours), and weighed (± 0.01 g) . Data 

 were expressed as dry weight totals 

 per sample. 



River flow data (Blountstown, 

 Florida) were provided by the U. S. 

 Army Corps of Engineers (Mobile, 

 Alabama). Air temperature and local 

 rainfall data were provided by the 

 Environmental Data Service (National 

 Oceanic and Atmospheric Administra- 

 tion, Apalachicola, Florida). Rain- 

 fall data in the Tate's Hell Swamp 

 were provided by the East Bay for- 

 estry tower (Apalachicola, Florida). 



RESULTS AND DISCUSSION 



Various studies (Livingston et 

 al. 1977; Livingston and Duncan, 

 1979; Meeter et al., 1979) have indi- 

 cated the relative importance of 

 meterological conditions such as 

 temperature, local rainfall, and 

 river flow on the spatial and tem- 

 poral aspects of habitat in the 

 Apalachicola estuary. Such func- 

 tions, over the study period (1975- 

 1980), are shown in Figure 2a. While 

 the average summer high temperature 



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