ДОМІНУЮЧІ КОМПЛЕКСИ ВИДІВ У МЕТАУГРУПОВАННЯХ ВОДОРОСТЕЙ ПЛАНКТОНУ, БЕНТОСУ, ПЕРИФІТОНУ

This paper proposes a systematic methodological approach to identifying dominant species complexes in algal metacommunities. The approach was applied during comprehensive studies of plankton, benthos, and periphyton in various lotic and lentic continental ecosystems. The algorithm of the proposed approach consists of the following steps: - Selecting the dominant species complex based on both cell count and biomass, as algal communities comprise species that vary significantly in cell volume (ranging from a few cubic micrometers to several tens of thousands of cubic micrometers). - Using relative abundance rather than absolute cell count or biomass to determine dominance, due to the high variability in algal abundance caused by abiotic, biotic, climatic, and anthropogenic factors. - Differentiating between dominant species (≥10 % of the total cell count or biomass) and subdominant species (5-9.9% of the total cell count or biomass). - Analyzing the spatial dynamics of dominant species complexes within a metacommunity framework, considering their distribution and interactions across three-dimensional space - i.e., among phytoplankton, benthic, and periphytic algal communities. The dominant species complexes in lotic and lentic ecosystems may be classified into: - Monodominant complexes, primarily composed of Bacillariophyta. - Oligodominant complexes, such as Bacillariophyta-Cyanobacteria and Bacillariophyta-Chlorophyta associations. - Polydominant complexes, involving Bacillariophyta - Cyanobacteria -Chlorophyta assemblages. The presence of planktonic Cyanobacteria in periphytic algal communities is attributed to the mass effect - a process in which species sediment from the water column, where they are abundant, onto an atypical habitat, such as hard substrata. Conversely, species may also transition from the substrata into the water column, further supporting the concept of a unified autotrophic network in aquatic ecosystems. Thus, analyzing the structure of dominant species complexes - while accounting for dominant and subdominant species in planktonic and periphytic algal metacommunities - is a crucial aspect of hydrobiological research in lotic and lentic continental ecosystems of Ukraine.