[en] Cyanobacteria evolved under the harsh conditions of the Precambrian and their
modern representatives retain a remarkable ability to adapt to and survive within
extreme conditions. They dominate terrestrial and freshwater cold ecosystems of
the Arctic, Antarctic and alpine regions, even though they do not seem to be
specifically adapted to optimal growth at low temperatures. They play a major
ecological role as they often are primary colonisers of substrates and major
primary producers in these ecosystems.
The application of molecular tools in combination with classic morphological
techniques has begun to provide new insights into the real diversity of
cyanobacteria and their biogeographical distribution in cold environments. Our
survey of recent studies suggests complex distributional patterns of cyanobacteria,
with cosmopolitan, endemic, and habitat-specific genotypes. This ongoing
research will help to identify specific geographical areas that have unique
microbial communities. However, many more studies are needed to unravel the
enormous diversity of cyanobacteria and to better define their biogeographical
patterns in cold environments. This is an urgent task in view of the climatic
changes that will undoubtedly alter the structure and functioning of microbial
communities in polar and alpine ecosystems.
