|
| |
|
|
Algae and extreme environments - ecology and physiology
Elster, Josef
All photoautotrophic prokaryotes have evolved from the group Eubacteria. From fossil remains in the form of stromatolites, it has been possible to date the first prokaryotic oxyphototrophic algae (Cyanobacteria) back to almost 3,450 million years. Evolution of Eukaryotic Algae did not occur until about 700-800 million years ago. The endosymbiotic hypothesis is the most accepted theory for the origin of eukaryotic organells. Oxyphototrophic microorganisms (cyanobacteria and algae) are ubiquitous and, because of their evolutionary antiquity, are widely adapted to all the extremes related with the many changes in geological time. During the last ten years special attention has been given to study of cyanobacteria and algae in environment with extreme environment. The methodology has been steadily developing for biological-taxonomical and ecological-physiological studies.
|
|
| |
|
|
Systém říčních ramen a aluviálních tůní vysoké Arktidy
Elster, Josef
During last ten years the ecology of shallow streams, rivers and poolsin newly deglaciated areas of the High Arctic (Ellesmere Island - CanadianArctic, Svalbard - Norwegian Arctic archipelago) and the Antarctica (KingGeorge Island, South Shetland) was studied. Cyanobacteria and eukaryoticalgae, frequently produce visible biomass and, play an important role inthese biocenoses.At the end of glacial period (about 18 thousand years ago) the area ofthe Czech Republic was surrounded by glaciers (from north - the continentalglaciation, and from the south - the Alpine glaciation). The north and thesouth glacial masses strongly influenced the ecosystem of this area, and canbe compared with the polar areas which are, at present time, influenced byclimate change.The ecology of alluvial pools discussed on the conference were and, innear future, has to be compared with results which are available from theshallow wetland ecosystem of polar regions.
|
|
| |
guest ::
RSS feed.