Features of formation of the dominant phytoplankton complex in water bodies of different types

Abstract

Many years of research (2005–2020) established the peculiarities of the formation of the dominant phytoplankton complex of various water bodies of Ukrainian Polesye (rivers, lakes, reservoirs and quarries). In different seasons, 216 species were dominant, which is 24.6 % of the total number of reservoirs and watercourses of the region identified as part of phytoplankton. In terms of floristics, dia-toms (29.7 % of the total number of dominant species), green algae (24.1 %) and euglena algae (19.4 %) are the richest in the dominant com-plexes.

This ratio is inherent in the algae groups of plankton of all studied types of aquatic ecosystems.

The greatest similarity in the composition of dominant complexes is characteristic of plankton of rivers and reservoirs created on them (k = 0.48), and a significant similarity was found between the lists of dominant species of lakes and reservoirs formed at the site of flooded quarries (k = 0.41).

In most of the studied water bodies the saturation of the dominant complexes did not change significantly during the growing seasons, only in Didovo and Ostrovsky lakes in the summer there was an increase in the number of species that form the dominant complex, with sub-sequent depletion in autumn.

Eleven species and intraspecific algal taxa new to Ukrainian Polissya have been identified in the dominant phytoplankton complexes. The appearance of new species in the dominant complexes for the region is largely due to changes in the hydrological and hydrochemical re-gimes of reservoirs and watercourses associated with over-regulation, drainage reclamation, climate change and the emergence of new types of reservoirs at the site of flooded mining quarries.