INCOMING ENERGY and NUTRIENTS 



<z> 



Leost 

 Weasel 



iwy Owl I 

 and L— 

 aeqgrs | 



Lemmings 



Lon(«»«'l 



T 



Pnmory Producers 

 TerfestriQl 



Standing Deod 



Aguot'C 

 Pfedotors 



Aquotic 

 Grozers 



1 



Primary Producers 

 Aquatic 



Soil 

 Carnivores 



Soprovores 

 1 



Decomposers 



Organic 

 Sediment 



Mineral 

 Soil 



PERMAFROST 



Figure 6. Major pathways of exchange oi energy and nutrients in the wet arctic 



tundra ecosystem. 



populations may be identified. In other areas, where diversity is greater and our knowledge is 

 less precise, functional groupings are indicated. The research design may be compared with this 

 HKxiel to determine the degree to which the important compartments and transfer processes are 

 being considered. Thus, a model of this nature is useful in directing research. 



The next step in modeling is the quantification of a model such as that discussed above. At 

 any given time of the season the quantity of energy, or of some key nutrient, in each of the compart- 

 ments may be measured or estimated. This produces a static model - a quantitative description 

 of the state of the system at any point in time. The collection of these data was one of the ob- 

 jectives of the 1970 research design. 



Each of the transfer processes within the system may be described by an equation which takes 

 into account the quantity of energy (or nutrients) in the compartments directly involved in the trans- 

 fer and the set of biotic and abiotic factors which influence the rates of transfer. For example, the 



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