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Jiří Komárek, Lubomír Kováčik, Josef Elster and Ondřej Komárek

Abstract

The diversity of cyanobacterial assemblages from various microhabitats in the Arctic area of Petuniabukta, Billefjorden, central Svalbard, was described. The present article contains the introductory common review of the cyanobacterial diversity and ecological data concerning main habitats, while the characteristics of individual taxonomic groups will be presented in following specific studies. Eight distinct main habitats were recognized, which differed in their species composition and especially the dominant species. More than 80 morphospecies were registered during our investigation, but only about 1/3 of them could be assigned to known and described taxa. The others require additional analyses based on mod- ern taxonomic methods (the polyphasic approach). The composition of cyanobacterial micro- flora was comparable with assemblages in coastal Antarctica. The diversity of unicellular and colonial morphotypes (36 taxa) was higher than other groups. The number of filamentous spe- cies without heterocytes and akinetes, with 30 species, and heterocytous types, with only 20 species, were similar in both of these ecosystems. These numbers will be surely changed in the future, but the overall proportion of different groups will likely stay the same. In contrast to the limited species diversity, simple filamentous aheterocytous species were dominant and formed massive populations. Few heterocytous taxa,mostly groupedwithin the genus Nostoc (N. commune-complex), were dominant in tundra soils.

Open access

Lenka Caisová, Tomáš Bešta, Jiří Chlachula, Jiří Komárek and Štěpán Husák

Taxonomic investigations of cyanobacterial and algal flora from the Southern Altai, East Kazakhstan

The study presents results of pilot investigations (2005-2007) of micro-vegetation biodiversity in marginally explored mountain and forest-steppe areas of southern Altai, East Kazakhstan. On the basis of morphological phenotypes and ecological demands a total of 351 taxa of cyanobacteria and algae were identified in the principal biotopes (rivers and streams, backwaters, irrigation channels, lakes, high-tundra periglacial and barren land settings, snow fields, and pedogenic /soil cover/environments) of the territorial topographic gradient of ca. 400-3900 m a.s.l. Microbiological records display a remarkable taxonomic variability, including several previously undescribed endemic species of algae adapted to locally specific geoenvironmental conditions. The present results show a major potential for future systematic phycological studies integrated in the complex nature monitoring and management strategy in protected areas of the Altai. The results also demonstrate a limited impact of modern human activity on the quality of local water sources with only minor present ecological risks in balance with the traditional lifestyles of pastoralist communities.

Open access

Otakar Strunecký, Jiří Komárek and Josef Elster

Abstract

Filamentous types from the order Oscillatoriales, particularly the species Phor- midium autumnale, have widely diverse morphotypes, which dominate in Arctic aquatic microbial mats and wet soils. We cultivated 25 strains of Ph. autumnale from Svalbard and compared them with available strains from surrounding regions. The comparison of strains, based on 16S rDNA and 16S-23S rDNA intergenic spacer sequences, revealed the similar- ity of strains from Ellesmere Island, the Canadian Arctic and Abisko, Sweden with strains from Svalbard. The rate of colonization of Ph. atumnale from aquatic habitats is relatively high and we suggest geese as a main transmission vector from surrounding lands. Strains of Ph. autumnale were positioned in the phylogenetic tree according to their occurrence in similar habitats. An apparent clustering factor is the duration of availability of water in lakes and long-lasting streams in contrast to rapid and repeated desiccation in soil and on wetted rock in the spray zone of waterfalls. Strains that grow in very cold waters just above the melting point of snow or ice form a distinct genetic group. The strains investigated in this study show morphological similarity in the shape of the trichomes of the studied specimens. Overall, the cell diameter, except for terminal cells, of our strains varied between 3 and 10 μm. Comparison of 16S rDNA sequences of the genus Ph. autumnale with the previ- ously published definition of the species Microcoleus vaginatus revealed the identity of these two species.

Open access

Lubomira Burchardt, František Hindák, Jiří Komárek, Horst Lange-Bertalot, Beata Messyasz, Marta Pikosz, Łukasz Wejnerowski, Emilia Jakubas, Andrzej Rybak and Maciej Gąbka

Abstract

Getting to know the response of different groups of aquatic organisms tested in altered thermal environments to environmental conditions makes it possible to understand processes of adaptation and limitation factors such as temperature and light. Field sites were located in three thermally abnormal lakes (cooling system of power plants), in eastern part of Wielkopolska region (western Poland): Pątnowskie, Wąsosko-Mikorzyńskie and Licheńskie. Water temperatures of these lakes do not fall below 10°C throughout the year, and the surface water temperature in spring is about 20˚C. In this study, we investigated the species structure of the spring phytoplankton community in a temperature gradient and analyzed diversity of periphyton collected from alien species (Vallisneria spiralis) and stones. 94 taxa belonging to 56 genera of algae (including phytoplankton and periphyton) were determined. The highest number of algae species were observed among Chlorophyta (49), Bacillariophyceae (34) and Cyanobacteria (6). In spite of important differences in temperature in the investigated lakes, taxonomic composition of phytoplankton was comparable. Thermophilic species: Glochidinium penardiforme and Cylindrospermopsis raciborskii were found in the species structure (blooms were not observed). The obtained data also showed that the biotic surface of Vallisneria spiralis was a better substrate for Bacillariophyceae colonization than stones. The examination in the spring season of these thermally altered lakes, indicated the taxonomic composition of phytoplankton typical for eutrophic reservoirs (not heated). There was no replacement of any phytoplankton groups which are characteristic for spring conditions, even if there were changes in the competition dynamics.