On the example of the small Lososna river (Grodno, Belarus), the changes in the phytoplankton community in urbanized areas for the period 2015–2018 are shown and compared with the data previously obtained in 2008. The species diversity of the Lososna river phytoplankton was represented by 87 species from six divisions dominated by Chlorophyta and Bacillariophyta (the algocenosis is dominated by the chlorophytic-diatom complex). There was an increase in species diversity relative to 2008 (36 species), which indicates a positive dynamic of reducing the inflow of pollutants into the watercourse. The calculated saprobity indices correspond to the β-mesosaprobic type, which makes it possible to attribute the water of the Lososna river to the 4th rank and III class of water quality (satisfactory purity), and to characterize changes in the ecosystem as reversible.
Keywords: anthropogenic impact, phytoplankton, saprobity index, small rivers, species diversity, water qualityAll articles can be accessed under Creative Commons Attribution 4.0 International Public License (CC BY 4.0).