The results of a phytoperiphyton study in the Kem River and its 9 tributaries in the Republic of Karelia is presented. Taxonomic composition, ecology, and spatial dynamics of attached communities are analysed. A total of 179 species, varieties, and forms of algae from 5 divisions were identified: Cyanophyta () (27), Ochrophyta (111), Dinophyta (1), Rhodophyta (2), and Chlorophyta (38). The basic principles of the formation of the phytoperiphyton structure are discussed. Based on the analysis of the taxonomic composition and structure of the phytoperiphyton communities, their similarities are shown. Studied algal flora is characterized by significant asymmetry at the level of algal divisions. Ochrophyta, comprising 111 species from 3 classes, dominates in species richness. The leading class is Bacillariophyceae; it is typical for the structure of the phytoperiphyton of freshwater systems of the Republic of Karelia. The composition of the leading families is also characteristic of the northern region. Fragilariaceae (16 species), Naviculaceae (47), and Desmidiaceae (19) are the most important families in terms of phytocenology. In total, they comprise 82 species: almost 50% of revealed algal species. The group of leading genera (59 species, 33%) includes Cymbella C.Agardh (15 species), Eunotia Ehrenberg (14), Navicula Bory (12), and Cosmarium Ralfs and Fragilaria Lyngbye (9 species each). The dimensional structure of the periphyton is formed by species that differ markedly in size: from a few microns to several centimeters. The species dominating in number and biomass are also markedly different. In number, 35 species dominate; in various sites, the number of phytoperiphytic species ranged from 0.1 × 104 up to 1690.5 × 104 cells/cm2. Sixteen species dominated in number only in one site; another 6 species were dominants in two sites. Only four dominant species (Tabellaria fenestrata (Lyngbye) Kützing, T. flocculosa (Lyngbye) Kützing, Eunotia pectinalis (Kützing) Rabenhorst, and Achnanthes minutissima Kützing) had a frequency of occurrence of more than 50%. Eleven species dominated in terms of biomass, whose values varied from 0.01 to 11.8 mg/cm2. In terms of ecological and geographical peculiarities, most of the revealed algae are common oligohalobic species, acidophilic, or indifferent with respect to the pH of the environment. Based on the relatively high contribution of indicator species in the formation of periphytic communities, the water of the studied water bodies represents the second class of water purity.
Full text: PDF (Rus) 547K