ABSTRACT

Microbiological processes of organic matter production and decomposition were studied in oligo- and meso-poly-humic water bodies of Karelia classified as acidic, slightly acidic, and neutral ones. The tendency for a decrease in organic matter primary production and biosynthetic activity of bacteria was registered with decreasing pH of water related to the deterioration of the processes of CO₂ fixation both in the light and in the dark. This phenomenon was conditioned by the disruption of relationships among various forms of carbon and by almost a total absence (disappearance) of hydrocarbonate ions in the water bodies with pH = 5.5. The peculiarities of the processes of acidification occurring in oligo-humic and meso-poly-humic water bodies are considered.