has developed the concept of energy flows and 

 interactions, which can be illustrated through ener- 

 gese diagi'ams. This energy concept can be 

 developed to a sophisticated science of quantitative 

 ecological system modeling when such data are 

 available (Hall and Day 1977). Flow diagrams can 

 be used, for example, to translate an understanding 

 of biogeochemical cycling which is essential to the 

 appreciation of the interactions among living and 

 nonliving components (Hutchinson 1944, 1950). 

 Likens et al. (1977) have studied these cycles in 

 depth and have quantified certain biogeochemical 

 pathways in a terrestrial system in New Hampshire. 

 Food webs are used to illustrate interactions 

 between the plant and animsd components of a sys- 

 tem. Abiotic factors interact to form the habitat 

 templates governing the use of an area by the biota. 

 Ecologists apply any one or combinations of the 

 four primary concepts to illustrate and compre- 

 hend interactions in ecological systems; we have 

 attempted to apply all of these concepts to illus- 

 trate interactions. It is important to realize that 

 these concepts are not exclusive of each other but 

 overlap and are complementary. Here they are 

 applied to the ecosystems, systems, and classes 

 found on the Maine coast and become the frame- 

 work of the conceptual model (fig. 11). 



THE GROUPS-OF-INTEREST APPROACH 



Another approach to understanding the Maine 

 coast ecosystem is to translate an organism's de- 

 pendency on and participation in the interactions 

 previously discussed. 



The ecosystem approach emphasizes the habitat 

 as an entity. In the groups-of-interest approach, 

 interrelationships between commercially and 

 ecologically important groups of species and their 

 environments are emphasized (fig. 12). The uses of 

 habitats for various life stages, reproductive strate- 

 gies as controlled by limiting factors, and the 

 importance of man and management are discussed. 

 Case studies illustrating the above concepts are in- 

 cluded within the discussion of each group of in- 

 terest. 



This section complements the ecosystem 

 approach in that it illustrates the varied needs of 

 important organisms in terms of habitats and com- 

 ponents of habitats. 



THE ATLAS 



The Atlas presented as a volume of the report 

 is to be used in conjunction with the text. Table 1 

 lists the contents of the Atlas. The specific maps 

 and overlays illustrate locations of selected com- 

 ponents and aid in directing interactions of driving 

 forces and components. 



Table 1. Overlays of the Maine Test Characterization Atlas 



Figure 11. A conceptual model illustrating the 

 interactions of the primary concepts applied to the 

 Mame coast ecosystem. 



National Wetlands Inventory 



Land cover 



Marine geology 



Soils 



Substrates 



Sea bird, wading bird, 

 shore bird, eagle, and 

 osprey nest sites 



Shellfishes, marine worms 



Harbor seal haulout sites 



Tidal range, currents 



High and low water 



Point sources 



Named lakes with sum- 

 marized data 



Wedands important to 

 waterfowl; rivers evalu- 

 ated for fisheries 



Migratory and anadrom- 

 ous fish 



Estuarine and riverine 

 fish 



Marine fish, lobsters 



53 



