[Characteristics of the biological effects of silicon monoxide].
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Air Pollution↗
Biomedical subjects
T I Kazantseva
Publications and source records attributed to T I Kazantseva.
[The budget model of ecosystem of a shallow highly eutrophic lake].
A model of energy budget of Lake Bolshoi Okunenok ecosystem was based on the data received during field studies from May through November 1986. The model takes into account 36 components including dissolved organic matter, bacteria, phytoplankton, zooplankton, meiobenthos, macrobenthos, fish, suspended and sediment detritus. The growing season has been divided into 16 intervals according to the number of observations. The balance equation for each live component describes the change in its biomass for a time interval between two successive sampling dates. The change is considered as a balance of energy input with assimilation or feeding, and energy loss due to respiration, excretion, predation, natural mortality, fishery catchment or and emergence of imago insects. For non-live components we estimate an increase and a decrease in their mass due to the activity of living organisms, as well as organic matter exchange between water and sediments. Seasonal value of balance elements for each component are equal to sums of appropriate interval value. Comparison of energy flows through different links of a trophic web has shown that the role of a bacterial-detrial link was extremely important in Lake Bolshoi Okunenok for the growth season of 1986. Detritus constituted 58% of seasonal diet of non-predatory zooplankton, 39% of diet of predatory zooplankton, 50% of diet of planktivorous fish (fry of whitefish) and 92% of diet of benthivorous fish (fry of carp). The contribution of bacteria to the total seasonal decomposition amounted to 46%. Approximately 57% of the forage phytoplankton production, 86% of non-predatory benthos production, and 23-38% of the other trophic groups production were consumed by all grazers. "Coefficient of energy transformation" is proposed. It is calculated as: CET(s, k) = Ps(k)/Pk, where Ps(k) is production of consumers "s", built due to consumption of source "k"; Pk is production of source "k" itself. In Lake Bolshoi Okunenok only 14% of energy built by phytoplankton were accumulated in organic matter of zooplankton due to direct consumption.
Animals↗
[Relationships between basic life history parameters and population size].
We consider an ideal population with a stable age composition changing according Lotka equation. Additional assumptions are made concerning the constancy of population size, independence of specific mortality rate on age, and linear dependence of female fecundity on its weight. A relationship has been obtained [formula: see text] where N0 is initial numbers of a generation, N[alpha, omega] is total numbers of the mature part of the population, w[alpha, omega] is a mean weight of a mature individual, s is sex ratio, c is specific fecundity (per unit of weight) and l0 is the probability of larval surviving. The growth of an individual is described by the Bertalanffy function. Methods of calculation of life history parameters are discussed. A method is proposed to calculate the age of maturity (alpha) and at the end (omega) of the reproduction period as first and second inflection points of the growth rate curve. Based upon data on development of 27 populations of several species of fishes of inland waters of Russia the following relationship have been obtained: [formula: see text] for populations with [formula: see text] < or = 100 g, [formula: see text] for populations with [formula: see text] > 100 g, and [formula: see text] for all populations.
Animals↗
[A concept of relation between physical and biological time in animals].
A definition is proposed for biological ("internal") time tau(t) for a growing organism whose weight variation obeys the law w(t): tau(t) = 1/c(w) (t) = w(t)/w'(t), where t is physical ("external") time, w'(t) is weight increase rate, and c(w) (t) = w'(t)/w(t) is specific growth rate. Properties of functions tau(t) and w(tau) were studied for those cases when growth curves w(t) were described by Bertalanffy's or logistic equations.
Animals↗
[Comparative analysis of the energy flows in the ecosystem of a small eutrophic lake during three vegetation seasons (balance model)].
Seasonal energy flows were calculated, based on a simulation balance model, from unique data collected during three vegatation seasons, 1986-1988, in the ecosystem of the Lake Bolshoy Okunyonok, Leningrad province. The model is based on principles developed by G.G. Winberg's school of production hydrobiology and was described in detail in an earlier work (Kazantseva, 2003). Analysis and comparison of the results showed that certain regularities of energy transformation processes in any lake ecosystem are apparent in spite of natural differences determined by differences in the environment properties and the levels of development of the ecosystem components. For instance, the extreme importance of the bacteriadetritus element in the food chains of water-body was confirmed. Broad spectrum of food and considerable changes in food composition during a vegetation season were clearly shown for most hydrobionts. The degree of consumption was estimated for the production of the organisms at each trophic level. It was shown that all the consumers eat away ca. 50-60 per cent of the production of the forage phytoplankton, 90 per cent of the production of non-predatory benthos, and 20-50 per cent of the production of the other trophic groups during a season. The proposed coefficient of energy transformation, CET(s, k) = Ps(k)/Pk, where Ps(k) in the production of the consumer s created by consuming the source k, and Pk is the production of the source itself, proved to be more stable than the generally accepted coefficient q = Ps/Ps -1.
Ecosystem↗