The Phycology group is focused on description of diversity of cyanobacteria and algae in the studied area and selected environmental factors in which these communities live. The cyanobacteria and algae are studied in marine littoral and in all types of terrestrial biotopes like shallow lotic and lacustrine wetlands, soil crusts, ornithogenic soils, wet tundra, wet rocks, cryoseston, cryoconites, surfaces of glaciers, lichens, biotops affected by human activities or brackish coastal wetlands. According to this description, suitable populations of cyanobacteria and algae are selected for further detailed ecological and ecophysiological studies.

Microenvironment diversity in Svalbard. In front: wet tundra meadow with small lakes; in background: moraine and Nordenskiold glacier.

The polyphasic approach combining classical microscopy observations and data obtained from DNA sequenation is used for taxonomical determination of individual species. The algal and cyanobacterial strains are kept at working collection and their transfer to the Culture Collection of Algal Laboratory (CCALA) of the Institute of Botany AS CR in Třeboň is intended.

Nostoc commune s.l., typical cyanobacterium in a wet hummock tunda. Left: real colony size; right: microphotography of internal colony structure.

The ecological observations are focused on evaluation of environment characteristics and its stability in time in biotopes mentioned above. The observations include one-time or continuous measurements of the basic environmental factors (physical and chemical parameters of soil and water, diurnal course of temperature, irradiance, depth of visibility, pH, oxygen concentration, conductivity, soil water content, etc.). These measurements are followed by determination of species composition of cyanobacteria and algae, and their primary production. Since 2009, the experiment in the Open-Top-Chambers has been performed at different localities for evaluation of the effect of mild warming and changes in soil water content on the algal and cyanobacterial communities in the wet hummock tundra and in on soil crust communities.

The OTC experiment in the hummock tundra.

The ecophysiological properties of polar algae and cyanobacteria are investigated in field measurements as well as in laboratory experiments. The Svalbard field experiments are focused on monitoring of photochemical activity and nitrogen fixation (nitrogenase activity) in cyanobacterium Nostoc sp. colonies in OTC experiment and in other manipulative ones, e.g. evaluation of desiccation effects, on studies of dormant stages formation in algae and cyanobacteria, and on study of photochemical processes in different kids of biotopes. The laboratory experiments are focused on determination of ecophysiological requirements of individual species and on detailed study of their response to various ecological factors.

Experimental site with green alga Zygnema community.

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Josef Elster, Jana Kvíderová