226 



WOODWELL, RICH, AND HALL 



ATMOSPHERE 

 DIFFUSION 



Q 



z 

 3 



< 



_i 



I 0— ^ 



g (0-^ 



PLANKTON *£ 



FISHERIES 



SEDIMENTS 



SEDIMENTATION 



Fig. 2 Model of the carbon budget of Flax Pond, an estuarine marsh on the 

 north shore of Long Island. Major exchanges occur between the marsh and 

 Long Island Sound, the atmosphere, the sediments, and the uplands as 

 indicated by the four sides of the diagram. 



other systems to both the estuary's net production and net ecosystem 

 production. Should that segment of net production of the estuary that is 

 exported be considered part of net ecosystem production? 



The earlier applications of net ecosystem production were to terrestrial 

 ecosystems where exchanges with other systems were very small and could be 

 ignored. In those instances, net ecosystem production was an expression of the 



