Permafrost Soils

Recent knowledge on permafrost and permafrost-affected soils is summarized here, including their typical properties, the distribution and biodiversity of permafrost microorganisms, and genomic and proteomic insights into cold adaptation of permafrost bacteria.

Most of the Earth's biosphere is characterized by low temperatures. Vast areas (>20%) of the soil ecosystem are permanently frozen or are unfrozen for only a few weeks in summer. Permafrost regions occur at high latitudes and also at high ele- tions; a significant part of the global permafrost area is represented by mountains. Permafrost soils are of global interest, since a significant increase in temperature is predicted for polar regions. Global warming will have a great impact on these soils, especially in northern regions, since they contain large amounts of organic carbon and act as carbon sinks, and a temperature increase will result in a release of carbon into the atmosphere. Additionally, the intensified release of the clima- relevant tracer gas methane represents a potential environmental harzard. Significant numbers of viable microorganisms, including bacteria, archaea, p- totrophic cyanobacteria and green algae, fungi and protozoa, are present in per- frost, and the characteristics of these microorganisms reflect the unique and extreme conditions of the permafrost environment. Remarkably, these microorg- isms have been reported to be metabolically active at subzero temperatures, even down to ?20°C.

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Texte du rabat

Most of the Earth s biosphere is characterized by low temperatures. Vast areas (>20%) of the soil ecosystem are permanently frozen or are unfrozen for only a few weeks in summer. Permafrost regions occur at high latitudes and also at high ele- tions; a significant part of the global permafrost area is represented by mountains. Permafrost soils are of global interest, since a significant increase in temperature is predicted for polar regions. Global warming will have a great impact on these soils, especially in northern regions, since they contain large amounts of organic carbon and act as carbon sinks, and a temperature increase will result in a release of carbon into the atmosphere. Additionally, the intensified release of the clima- relevant tracer gas methane represents a potential environmental harzard. Significant numbers of viable microorganisms, including bacteria, archaea, p- totrophic cyanobacteria and green algae, fungi and protozoa, are present in per- frost, and the characteristics of these microorganisms reflect the unique and extreme conditions of the permafrost environment. Remarkably, these microorg- isms have been reported to be metabolically active at subzero temperatures, even down to ?20°C.

Contenu
Geological, Chemical and Physical Properties of Permafrost.- Arctic Permafrost Soils.- Antarctic Permafrost Soils.- Mountain Permafrost.- Biodiversity in Permafrost.- Very Old DNA.- Bacterial and Archaeal Diversity in Permafrost.- Viable Cyanobacteria and Green Algae from the Permafrost Darkness.- Fungi in Permafrost.- Ancient Protozoa Isolated from Permafrost.- Biological Activity in Permafrost.- Microbial Activity in Frozen Soils.- Anaerobic Ammonium Oxidation (Anammox).- Genomic Insights into Cold Adaptation of Permafrost Bacteria.- Proteomic Insights: Cryoadaptation of Permafrost Bacteria.- Impact of Global Warming On Permafrost Properties.- Global Warming and Thermokarst.- Global Warming and Mountain Permafrost.- Global Warming and Carbon Dynamics in Permafrost Soils: Methane Production and Oxidation.- Global Warming and Dissolved Organic Carbon Release from Permafrost Soils.- Climate Change and Foundations of Buildings in Permafrost Regions.- Contaminants in Frozen Ground.- Migration of Petroleum in Permafrost-Affected Regions.- Remediation of Frozen Ground Contaminated with Petroleum Hydrocarbons: Feasibility and Limits.- Application of Reactive Barriers Operated in Frozen Ground.- Permafrost on Earth A Model for Extraterrestrial Habitats.- Terrestrial Permafrost Models and Analogues of Martian Habitats and Inhabitants.