Table 8. Physical, chemical, and productivity data taken from locations along the 

 northwest gulf coast of Florida (from R. L. Iverson and his students, unpublished data, 

 Myers 1977). Standard deviations () are also given. 



Drocessinq 

 al. 1979). 



(Odum and Heald 1972; Odum et 



Amonq the maior litter producers of 

 the Apalachicola flood plain. Cairns 

 (1Q81) and Elder and Cairns (1^82) found 

 decomposition rates of floodplain leaf 

 matter to he soecies-specif ic. Tupelo 

 ( N vs s a spp.) and sweetgum ( Liquidambar 

 styracif lua ) leaves decomposed completely 

 in R months. Leaves of baldcypress 

 (Taxodium distichum ) and diamond-leaf oak 

 ( Quercus'lauri^'ol ia ) were more resistant. 

 Water hickory fCarya aquatica ) had 

 intermediate decomposition rates. Rates 

 of carbon and biomass loss were linear 

 over a 6-month period, but phosphorus and 

 nitrogen leachinq was nearly complete 

 within a month. Periods of river floodinq 

 were particularly important for 

 mobilization of the litterfall into the 

 aquatic system. Floodinq immerses litter 

 material, increases decomposition rates, 

 and provides a transport medium. Because 

 of the high diversity of floodplain tree 

 species, the autumn peak of leaf fall is 

 relatively prolonged (September-December) 

 (Figure 24). Compared to the ACF system 

 as a whole, the Apalachicola flood plain 

 is extremely high in nutrient yield per 

 unit "area, especially for carbon and 

 phosphorus (Table 10). Mattraw and Elder 



(1982) postulated that the upper 

 ChattahoocheeFlint watersheds yielded 

 fewer nutrients because the 16 reservoirs 

 act as nutrient retention ponds. Although 

 headwater inflow provides substantial 

 loads of dissolved nutrients to the 

 estuary, particulate matter delivered from 

 the river is derived almost exclusively 

 from the Apalachicola/Chipola wetlands. 

 Approximately \^% of the organic carbon 

 delivered to the estuary is derived from 

 less than 1^ of the ACF basin (Mattraw and 

 Elder 1082). 



Particulate organic matter is 

 transferred from the river to the estuary 

 primarily during winter/spring floods, 

 athouqh there is no direct correlation 

 between microdetritus in the estuary and 

 river flow by season (Table 5). 

 Microdetritus flow is generally low during 

 summer and fall periods and highest during 

 the first river floods of winter (Figure 

 22). In the estuary, surface dissolved 

 nitrogen and phosphorus concentrations 

 peak during periods of high river flow 

 (Estabrook 1^73; Livingston et al . 1074, 

 1976a; Table 11). Thus, the degree and 

 timing of river flooding on a seasonal 

 basis determines the form and level of 

 nutrient fluxes into the estuary from the 

 river wetlands. 



37 



