%0 Journal Article %A Kolmakov, V. I. %A Gayevskiy, N. A. %A Dubovskaya, O. P. %A Ivanova, Ye. A. %D 2003 %I Begell House %N 1 %P 12 %R 10.1615/HydrobJ.v39.i1.10 %T Contribution of Phytoplankton of the Euphotic and Disphotic Zones to the Primary Production of a Fresh Water Body %U https://www.dl.begellhouse.com/journals/38cb2223012b73f2,0c6b227d725c2a4e,59e3109a511040e1.html %V 39 %X Investigations were carried out during two vegetation seasons in a shallow forest pond characterized by a low transparency of water. The structural (the species composition and biomass) and physiological (relationship between chlorophyll a content and algal biomass, variable fluorescence, gross and net primary production) characteristics of phytoplankton of the euphotic and disphotic zones were studied. Phytoplankton of the disphotic zone represented by a stable community of diatoms in terms of its physiological characteristics was assigned to shade-tolerant phytoplankton. Its contribution to the total primary production may account for 25%. The method of determining primary production in the disphotic zone in terms of variable fluorescence yields higher results as compared to the bottle method. It has been found that the main coefficient in the equation of relationship between fluorescence and productional indices depends on the intensity of light. %8 2003-03-01