The specific production of various elements of the community may also 

 vary significantly as a function of the trophic relationships which develop 

 in the community in various stages of its development. In general, as 

 the community matures, the specific production of certain of its elements 

 decreases, and in certain cases becomes negative (Vinogradov et al . , 1976) 

 (Fig. 3). 



Fig. 3. Change in daily specific pro- 

 duction (P/B) of various elements of a 

 plankton community as upwelling weakens 

 at the equator in the eastern Pacific 

 (Vinogradov et al . , 1976). 1, Phyto- 

 plankton; 2, Bacteria; 3, Protozoa; 



4, Herbivores and Omnivores; 



5, Carnivores; I, 97°W; II, 122°W; 

 III, 140°W, IV, 153°W. 



The actual and specific production of a zoocenosis and of an entire 



community are comparatively high in the early stages of development of 



the community, then decrease sharply or even become negative in the more 



mature stages, as dissipation of energy begins to occur in the community 

 (Table 1). 



All of the above leads us to the realization of the magnitude of the 

 structural and functional changes experienced by a pelagic community as 

 it grows and moves together with the water. Obviously, as we compare the 

 ecosystems of various localities within a single large region, we should 

 always keep in mind possible age differences of the communities, which may 

 be responsible for many of the differences observed. Only a dynamic, 

 succession approach to the study of ecosystems allows us to understand the 

 causal dependence of the processes occurring within them. 



22 



