“Karelian Lakes” expert system: 3. Model approach to studying fish communities

The final work on the development of an expert system for the assessment of the state and the rational use of lake??s resources is presented. A block of expert system for the assessment of ichthyocenoses is described. For this purpose, databases and knowledge bases on 12 species of most abundant Karelian fishes were used and a model of community, based on the principle of trophic chain, was proposed. The system was developed for water bodies with different compositions of ichthyocenoses and different food and abiotic conditions. The model makes it possible to assess the ichthyomasses and age structure of populations and to determine the rational ways to commercial use of the community for maximizing the catches with the preservation of biodiversity.     

Environments of the Russian Plain during the Middle Valdai Briansk Interstade (33,000–24,000 yr B.P.) Indicated by Fossil Mammals and Plants

Abundant mammal (45 localities) and plant (52 sections) fossil data collected from the Russian Plain deposits of the Middle Valdai Briansk Interstade indicate a period of noticeable warming. These materials were jointly analyzed. The data were organized in the database software PARADOX and then moved to the GIS program ARC/INFO. Mathematical methods as well as traditional research methods were used for the analysis. The reconstructed biogeographical provinces illustrate the specific environmental and climatic conditions of the Briansk Interstade. Analogues of modern natural zones did not exist at this time on the Russian Plain. The Briansk landscapes reflect the moderate-cool climate of this period, when the majority of northern subarctic plant and mammal species extended their ranges considerably to the south to the Central Russian Plain. At the same time, steppe species penetrated farther north and west. This combination shows that the continuous forest zone was destroyed during the Briansk Inter-stade. Five biogeographical provinces have been reconstructed from the north to the south for the Russian Plain during the Briansk warming on the basis of joint analysis of mammalian and botanical data.     

Comparison of Variations in Concentration of Arctic Marine Ice and Duration of Snow Period of Northern Eurasia under Conditions of Present-Day Climate According to Satellite Data

Izvestiya, Atmospheric and Oceanic Physics - The short period variability of the duration of the occurrence of stable snow cover and the concentration of marine ice is revealed and compared for...     

Relationships between Atmospheric Precipitation,Evaporation, Temperature,and Production of Aquatic Ecosystems

The average production capacity of aquatic ecosystems is shown to be proportional to the coefficient of variations of substance concentrations in atmospheric precipitation and the sum of effective temperatures. The values of ichthyomass and primary production of phytoplankton per 1°C of the sum of effective temperatures multiplied by the coefficient of variations of substance concentration in atmospheric precipitation are proposed as ecological thermometers to be used in water bodies in different geographic zones of Europe and North America.