Snow algae

from Wikipedia, the free encyclopedia
Snow algae

With snow algae is photoautotrope freshwater microorganisms that live exclusively in slowly thawing snow fields during the summer. They are known both from the polar regions and from many mountain regions such as the Alps.

Mass occurrences ("flowers") of these cells lead to lively discoloration of the snow, of which the red blood snow is best known due to its conspicuousness and frequency. The actual hue and intensity depend on both the cell concentration and the individual pigment composition of the predominant species:

Green snow
In the cells, the green chlorophylls dominate, the causers usually belong to the Chlorophyceae . Usually found in old snow in shaded locations (e.g. under trees) or at a depth of a few centimeters under protective white snow.
Yellow snow
In the cells, primary carotenoids dominate photosynthesis, e.g. B. Fucoxanthin in golden brown algae living in slush .
Red snow
Mostly found in heavily sun-exposed locations above the tree line. The secondary carotenoid astaxanthin dominates the cells in high concentrations. The red pigmentation, with its absorbing and antioxidant properties, serves to protect against abiotic environmental influences, as the algae can be damaged by the radiation prevailing on the snow surface. The best known representative of blood snow is the species Chlamydomonas nivalis .

Snow algae are biologically classified as cryoflora . In addition to plant organisms, animal organisms, the cryofauna , and certain microscopic fungi also occur on snow. All of these organisms are known as cryosis stones and inhabit the Kryal habitat .

swell

  1. P. Werner: Roter Schnee: or The search for the coloring principle. Oldenbourg Akademieverlag, 2007, ISBN 978-3-05-004432-3 .
  2. D. Remias: Cell Structure and Physiology of Alpine Snow and Ice Algae. In: C. Lütz (Ed.): Plants in Alpine Regions. Cell Physiology of Adaption and Survival Strategies. Springer, 2012, pp. 175-185. (on-line)
  3. E. Kol: Cryobiology: Biology and Limnology of Snow and Ice I, cryovegetation. (= The inland waters. Individual representations from limnology and its neighboring areas. Volume 24). E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 1968.

Web links