government expand, their management 

 functions increasingly become na- 

 ture's management functions as well. 

 The private control of vast acreages 

 of land for timber or agricultural 

 production, the designation and man- 

 agement of public lands for parks, 

 wildlife refuges, and conservation 

 areas, and the spread of urban and 

 suburban development, are not only 

 competing interests within man's 

 economy; they are also competing 

 with, and dependent upon, nature's 

 ability to self-regulate. To accu- 

 rately perceive the relationships 

 between man and nature in south- 

 western Florida it is essential to 

 understand that man himself is a 

 function of natural processes rather 

 than a force separate from them. 



With this in mind, the general 

 model in Figure 3 is constructed to 

 include the activities of man as an 

 integral part of watershed metabo- 

 lism. Curiously enough, man's 

 activities do not bring any new 

 principles to bear upon energy and 

 material flow through natural eco- 

 systems. Rather, his major impacts 

 are: 



(1) The selected conversion of 

 natural lands into agricul- 

 tural and timber production; 

 and 



(2) The funneling of natural and 

 manufactured resources into 

 the production and support 

 of complex cultural structu- 

 res (e.g., buildings, roads, 

 and industrial goods). 



A total conceptual model of the 

 present study area is presented in 

 Figure 4. This model identifies the 

 primary ecological zonations of the 

 watershed, namely: 



(1) The terrestrial and fresh- 

 water wetlands ecosystem; 



(2) The saltwater wetlands and 

 estuarine ecosystem; 



(3) The Florida Bay and mangrove 



island ecosystem; and 

 (4) The Florida Keys ecosystem. 

 For each of these zones or "ecosys- 

 tems", the habitats which they 

 incorporate are listed in Table 2. 

 Major forcing functions are shown 

 entering the model from the left 

 side of the figure. Chemical and 

 physical energy inputs are augmented 

 by imported goods and services which 

 support the activities of man, par- 

 ticularly in the Florida Keys and in 

 the East Everglades Agricultural 

 Area. Energy and materials are 

 exported from the watershed via (1) 

 evapotranspiration, (2) the emigra- 

 tion of species, (3) fisheries 

 industries, (4) tidal flushing and 

 runoff of chemical energy and sedi- 

 ment, and (5) export of agricultural 

 and manufactured goods. Within each 

 ecosystem the work of the plants and 

 animals is symbolized by the com- 

 bination of symbols presented in 

 Figure 2. Two major oceanic ecosys- 

 tems associated with the Florida 

 Straits and the southeastern Gulf of 

 Mexico, regularly influence the 

 watershed. They are also shown in 

 the model. The double-headed arrows 

 that run between major ecosystem 

 zones signify that energy and matter 

 flow between the respective subsys- 

 tems. These connections may take 

 the form of physical/chemical energy 

 transfers such as those effected by 

 runoff, hurricanes, or tidal mixing; 

 or biological energy transfers such 

 as those effected through the active 

 migrations of organisms. 



Man's role in watershed metab- 

 olism is represented by three some- 

 what distinct consumer, or manage- 

 ment, functions: 



(1) Urban/industrial structure, 

 primarily located on the 

 eastern margin of the Evei — 

 glades and in the Keys. This 

 includes the activities of 

 agriculture, commercial and 

 sport fishing industries. 



