As M. E. Vinogradov, E. A. Shushkina and I. V. Kukina (1976) have shown, 

 in the early stages of development of a community with high biomass of 

 autotrophs, the nutritional demands of the animals of all trophic levels 

 are satisfied to a high extent (6 - 0.8), supporting an increase which is 

 close to the maximum. As the community matures, the degree of satisfaction 

 of the nutritional demands decreases (6 ~ 0.4-0.5). As 6 decreases, the 

 stress on the trophic connections between organisms at various trophic 

 levels increases. The trophoecologic coefficient k, showing the measure of 

 pressure of consumers on the biomass of a given species, is less than 1 in 

 the early stages of development of a community for practically all of its 

 elements, whereas in more mature stages, particularly for the lower trophic 

 levels, it increases rapidly. 



On the basis of qualitative assumptions, it would seem probable that 

 as a community matures, the degree of balance between production and 

 consumption would increase. However, calculations show that the change in 

 the degree of balance occurs quite differently at different trophic levels, 

 and the assumption is valid only for some of them. Actually, the production 

 of phytoplankton or bacteria may be underutilized, not only in the early 

 stages of succession of the community but also, under certain conditions, in 

 later stages, meaning that the general discussion of the degree of balance 

 of production and consumption in communities of various stages of maturity 

 and various trophic structure is not well founded. 



The ecologic effectiveness of transmission of energy from one trophic 

 level to another (w) increases with increasing trophic level, and also 

 as the community matures and the degree of satisfaction of nutritional 

 demand decreases. 



Calculations of change of the actual (P) and specific (P/B) production 

 of various trophic levels of a community as it matures, performed for 

 communities around the eastern Pacific equatorial upwelling (Sorokin et al . , 

 1975a; b; Vinogradov et al . , 1976) have shown that the production of the 

 lower trophic levels (phytoplankton, bacteria, protozoa) decreases with 

 maturation of the community more strongly than the production of mesoplankton, 

 particularly predaceous forms. In certain groups (protozoa, predaceous 

 mesoplankton) in a mature community the actual production may be negative, 

 a result both of their increased consumption by other animals and of 

 cannibalism within the group itself. 



I nj 



^ij 



— is the index of the deqree of utilization of the 



energy accumulated in a lower trophic level by the next higher trophic level. 



21 



