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
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.
Josef Elster, Jana Kv