1972; Pasternak, 1974, Zaika, 1974). 



It is probable that the value of Kp depends directly on temperature 

 (Ivlewa, 1970; Mull in, Brooks, 1970) and feeding conditions (Klekowski 

 et al., 1972; Winberg, 1968; Klekovskiy, Shushkina, 1968; Mullin, 

 Brooks, 1970) and changes irregularly with the age of the animals 

 (Dryuchkova, 1967; Soldatova, 1970; Shushkina, 1972; Klekovskiy, 

 Shushkina, 1977), particularly if the value of production defined 

 considers the increase due to formation of reproductive products and 

 exuvia (Kmeleva, 1967). On the other hand, many authors report sharp, 

 irregular fluctuations in the values of K2 in various stages of 

 development of aquatic animals (Soldatova, 1970; A. F. Pasternak, 1974). 



Studies have shown that in calculating the mean daily value of 

 production of zooplankton on the basis of the physiologic method, one 

 can take K2 = 0.3-0.4 as the average value for a specific population, 

 with 0.6 as the maximum value. 



An estimate of the rate of production of individual trophic levels 

 (specific associations) in the communities studied can be obtained by 

 adding the production of specific populations of animals of the trophic 

 level in question, if there is no cannibalism. In certain cases, the 

 rate of production of phytophagous planktonic animals can be estimated 

 by the radiocarbon method (Chmyr, 1967); however, methodologic 

 difficulties make it necessary to correct the results produced by other 

 methods (Shushkina, Sorokin, 1969). Individual comparison of the values 

 of production determined by the radiocarbon and physiologic methods have 

 yielded similar results (Shushkina, 1971; Malovitskaya, 1971). 



3.2 Methods of Calculation of the Production of Communities 



Production rates of communities consisting of organisms of various 

 trophic levels cannot be determined by simple addition of the production 

 of individual trophic levels, since this sort of addition yields a 

 clearly elevated estimate. 



Net production of the whole plankton community (Pq). which 

 according to Winberg (1960) is equal to: 



Pq = Pp -.L Ri (3.2) 



^ i=B 



where Pp is primary production, R^- is the metabolic rate of different 

 elements of the community from bacteria (b) to predatory animals (s). 



The value Pq can also be calculated in another way (Zaika, 1972; 

 Shushkina, 1966): 



s s s s s 



Po =.l Pi +.LDi -.yCi =,l Pi -.y Ci-Uj^ (3.3) 



i=p 1=8 i=B l=p 1=8 



295 



