Chemical Properties

The pH of Arctic soils varies greatly (Table 1.4), and depends on the chemistry of the parent materials. The similarity of the pH to that of the parent material results, in part, because of cryoturbation, which not only mixes and translocates fresh parent material to the near surface, but also mixes soil material among the soil horizons. The nitrogen, potassium and phosphorus contents of Arctic soils are generally low (Table 1.4), since most of these nutrients are locked into the surface...

Martian Hydrosphere and Cryosphere 2121 History of Water on Mars

Different relief forms originating probably from liquid water activity have been observed on the Martian surface treelike systems of fluvial valleys morphologically similar to terrestrial river systems, great mega outflow channels without inflows, which have no terrestrial analogues, and thin gullies on crater walls. Dating of these forms based on crater density shows that valley systems cut through only the oldest, most cratered surfaces of the Noachian epoch, 4.6-3.9 billion years old. It was...

Volcanoes

One way to have liquid water on Mars at shallow depths would be through subglacial volcanism. Such volcano-ice interactions could be going on beneath the polar caps of Mars today, or even within the adjacent permafrost around the margins of the ice caps. Basalt lava fields are common on the Martian surface, and some cinder cones have been found near the polar caps. The rover traces on terrestrial ash fields and the Martian surface, as well as the chemical composition of basalts on Earth and...

Why Might Soil Respiration Produce Misleading Results

The gas exchange rates are measured instantly and with high precision. Care should be taken however about possible artifacts associated with the sticky nature of some gases, such as CO2. Recently, Panikov et al. (2006) measured CO2 evolution from frozen tundra samples and found abnormal response of sterile controls (auto-claved and refrozen sample) instead of declining, the rate of CO2 evolution from sterile controls increased (Fig. 9.3, insert). The most reasonable explanation was that...

Methane Oxidizing Proteobacteria

Based on their function as the major sink for methane in Arctic permafrost affected wetlands and tundra, methane-oxidizing Proteobacteria are also of importance for the greenhouse gas budget of these environments. Methane-oxidizing Proteobacteria represent a subset of methylotrophic bacteria. Through the activity of their specific enzyme, methane monooxygenase, they are specialized to utilize methane as their single carbon and energy source (Hanson and Hanson 1996). The group of...

Increasing Representation of Cultured Isolates

Methods to increase the representation of cultured microbial isolates from permafrost have recently been applied. For example, Vishnivetskaya et al. (2000) used natural permafrost sediment (NPS) enrichment to recover microbial isolates. NPS, consisting Table 5.2 Phylogenetic groups of Bacteria cultured from permafrost8 Table 5.2 Phylogenetic groups of Bacteria cultured from permafrost8 aGenera represented in at least two permafrost environments are indicated (+). The number of genera that were...

Ice Wedge Melting

Melting of ice wedges often produces high-centred polygons (Fig. 13.1) or, where thermokarst activity is pronounced, thermokarst mounds (French 1975 Lawson 1986). Mounds 3-15 m in diameter and 0.3-2.5 m high started to form mainly by thermokarst subsidence within 2-3 years of vegetation clearance in cultivated fields near Fairbanks as surface water ponded in small disconnected depressions, accelerating thaw of the underlying ice wedges (Pewe 1954, 1982). On eastern Banks Island, Canada, thermal...

Permafrost Sample Collection

The permafrost samples were obtained by slow rotary drilling without the use of any drilling solutions between 1991 and 1999. Evaluation of the aseptic sampling methods and contamination controls was done (Khlebnikova et al. 1990 Juck et al. 2005). The surface of extracted frozen core was trimmed away with a sterile knife, then immediately divided into sections of 5 cm long, placed in presterilized aluminum tins, sealed, and placed in frozen storage. All samples remained frozen throughout this...

Efficient Use of Resources

Efficiency of resource utilization may be key to the survival of heterotrophic microbes in frozen environments over thousands to millions of years. While little is known about how low temperatures affect resource efficiency in psychrophiles, study of the proteome of Methanococcoides burtonii suggested that efficient carbon utilization occurs during growth at low temperatures (Goodchild et al. 2004). Genome sequence analysis reveals that P. arcticus 273-4 can conserve resources via the...

Introduction

This chapter provides an introduction to mountain permafrost and a review of recent scientific progress. In it, we use rather few references to the scientific literature in order to make the text more easily readable. For further reading, we recommend, Haeberli et al. (2006), and Gruber and Haeberli (2007), two recent reviews in which the current state of the art is discussed in depth and in which extensive references can be found. Permafrost is lithosphere material that permanently remains at...

Taxonomic Diversity

Species diversity in eukaryotes, including fungi, inhabiting permafrost horizons, collected in the Arctic, has been the subject of intense research over the last decade (Dmitriev et al. 1997 Kochkina et al. 2001 Vishnivetskaya et al. 2003). However, the complete list of the fungi detected has not been reported. The published results are summed up in Table 7.1, which lists mycelial fungi detected in permafrost horizons of the Northern hemisphere. To make the picture complete, we also indicate...

Macromorphology

The morphologies of both the surface and subsurface of Arctic soils are shaped by cryogenic processes (Figs. 1.1 and 1.2). The soil surface is associated with various types of patterned ground caused by frost heave and sorting, while the subsurface is dominated by cryoturbation that results in irregular or broken soil horizons, involutions, organic intrusions, and organic matter accumulation, usually along the top of the permafrost table. Oriented rock fragments (Fig. 1.1), silt-enriched layers...

Conditions of Cryoconservation

We guess that the conditions under which protozoa cysts were buried and passed into the frozen state, as well as the conservation regime, had a considerable impact on the formation of the fauna of alive fossil protozoa. The cysts of protozoa may Fig. 8.5 Resting cysts of ancient protozoans. a, c Interference-contrasted images. b, d TEM-micrographs a, b Acanthamoeba sp. c, d Colpoda inflata. 1,4 ectocyst 2,6 endocyst 3 ostiole with operculum 5 mesocyst 7 granular layer. Bars 10 im Fig. 8.5...

Methanogenic Archaea

Methanogenic archaea represent a small group of strictly anaerobic microorganisms (Hedderich and Whitman 2006). They can be found either in temperate habitats like paddy fields (Grosskopf et al. 1998), lakes (Jurgens et al. 2000 Keough et al. 2003), freshwater sediments (Chan et al. 2005), in the gastrointestinal tract of animals (Lin et al. 1997), or in extreme habitats such as hydrothermal vents (Jeanthon et al. 1999), hypersaline habitats (Mathrani and Boone 1985) or permafrost soils and...

Influence of Freezing and Thawing Cycles on Petroleum Distribution

As is known, the freezing-thawing processes are attended by structure-forming processes which result in changes in soil properties, which in turns influence petroleum redistribution in the soil and its transformation, fractionating and formation of organic-mineral composition. Results from the experimental investigations of Chuvilin et al. (2001a, b) showed cryogenic expulsion of petroleum from freezing to thawing zone in several different freezing soils (Fig. 18.3). Barnes et al. (2004) showed...

Thermal Erosion

Thermal erosion occurs where flowing water melts ground ice by the combined effects of heat conduction and convection, and then mechanically erodes newly released sediment. It often occurs on hillslopes during periods of snowmelt or Fig. 13.2 Frozen badlands formed by intense thermal erosion of massive icy sediments exposed within a retrogressive thaw slump, Summer Island, Tuktoyaktuk Coastlands, Canada. Relief is 1 m between interfluves and gullies Fig. 13.2 Frozen badlands formed by intense...

References

Bakermans C, Nealson KH (2004) Relationship of critical temperature to macromolecular synthesis and growth yield in Psychrobacter cryopegella. J Bacteriol 186 2340-2345 Bakermans C, Tsapin AI, Souza-Egipsy V, Gilichinsky DA, Nealson KH (2003) Reproduction and metabolism at -10 degrees C of bacteria isolated from Siberian permafrost. Environ Microbiol 5 321-326 Bakermans C, Tollaksen SL, Giometti CS, Wilkerson C, Tiedje JM, Thomashow MF (2007) Proteomic analysis of Psychrobacter cryohalolentis...

Active Layer Deepening

Active-layer deepening is inevitable in areas of ice-rich permafrost because of interannual or longer term variations in thaw depth and leads to thermokarst subsidence. But evidence for subsidence is usually clear only where deepening has been substantial, where remnants of the unaffected ground surface remain, or where subsidence has altered the surface hydrology and vegetation. In the cryostratigra- phy, evidence for former active-layer deepening occurs where a thaw unconformity truncates...

Spatial Distribution

The processes that govern the existence and evolution of mountain permafrost can be categorized into the scales and process domains of climate, topography and ground conditions (Fig. 3.2). The climate scale governs the global distribution of cold climates in mountains. It refers to the influence that latitude and global circulation have on the general climatic characteristics of an area. These climatic conditions are then further modified by topography, which affects ground temperatures because...

Morphological Physiological and Biochemical Characteristics of Permafrost Fungi

Table 7.1 shows that the overwhelming majority of fungi isolated from permafrost strata form small unicellular conidia (e.g., Aspergillus spp., Chrysosporium spp., Penicillium spp., Phialophora spp.). Experience of successful cryopreservation of collection cultures demonstrates that fungi with small spores are better adapted to long-time preservation than fungi with other types of spores. Representatives of genera of which a characteristic is the ability to form large multicellular spores...

Active Method Modify Foundation Material Conditions Prior to Construction

A thin layer of thaw-unstable permafrost over bedrock or over thaw-stable soil can be replaced with thaw-stable soil. More often such replacement is not feasible or not economically justified. The other method of permafrost modification prior to construction is its preliminary thawing to a specific depth. Steam and water points and electrical heating have been applied for thawing. This method has been infrequently used in Alaska and Russia. Preliminary thawing of foundation soils is most...

Anammox in Permafrost

Although the anammox process has not been investigated in permafrost soils, marine anammox 16S rRNA sequences have been identified in Siberian frozen alluvial sandy loam, deposited in the Middle Pleistocene Epoch 300,000-400,000 years ago in the Cape Svyatoi Nos tundra zone on the Laptev Sea coast (Penton and Tiedje 2006). Rysgaard and Glud (2004) found that anammox was responsible for up to 19 of total N2 production in a Greenland Sea ice floe, but was not detectable in annual sea ice, perhaps...

Introduction to PRB 2021 PRB Function and Design

Prb Groundwater

PRB can remove and retain contaminants (such as dissolved metals) travelling in groundwater, degrade some contaminant compounds (such as chlorinated hydrocarbons) directly, or facilitate their degradation (for example through the retention and biodegradation of petroleum hydrocarbons). Barriers can be used to both arrest the migration of contaminant plumes as well as remediate contaminated sites. Barriers should be optimised for specific site settings and aquifer and contaminant chemistries in...

Anaerobic Ammonium Oxidation Anammox

The anammox reaction is anaerobic oxidation of ammonium coupled with nitrite reduction under anoxic conditions. This alternative nitrogen removal pathway was first proposed by Richards (1965), following observations of ammonium deficits in anoxic marine basins. Throughout most of the 20th century, ammonium was believed to be inert under anoxic conditions. Canonical denitrification liberates ammonium from organic matter during respiration, resulting in net accumulation in the sediment soil...

Soil Forming Processes

All soils are formed by the interaction of soil-forming factors, but because of the cold climate in the Arctic region, cryogenic processes, which lead to the formation of permafrost-affected soils, dominate the soil genesis. The presence and mobility of unfrozen soil water, as it migrates towards the frozen front along the thermal gradient in the frozen system, drives this process. The cryogenic processes that affect the genesis of Arctic soils are freeze-thaw, cryoturbation (frost churning),...

Next 100 Years

With climate warming predicted to continue during the next century, amplified in Arctic and sub-Arctic regions (ACIA 2005), thermokarst activity will generally spread and intensify still more. Thawing of permafrost is projected to be concen trated in the current discontinuous permafrost zone during the next 100 years (Deslile 2007). This is of particular concern in sub-Arctic Alaska, where 40 of the area may be susceptible to thermokarst (Jorgensen et al. 2007). Thus, global warming at high...

Conclusion and Perspectives

The growing interest in perennially frozen ground of cold mountain ranges is justified and the rapidly developing progress in this young research field must be considered timely and most welcome. Continued if not accelerating atmospheric temperature rise indeed has the potential to cause serious and long-lasting disequilibria on the slopes as well as inside many mountain peaks on earth. Concerning impacts of climate change on mountain permafrost, system reactions deserve special attention the...

Ancient Protozoa from Permafrost 821 Study Area

Yana Indigirka Lowland

Studies were carried out in the East Arctic sector, from the Lena delta to the lower reaches of the Kolyma in the continuous permafrost zone (Fig. 8.1). The territory is characterized by cold Arctic climate, with a mean annual air temperature of -13.5 C in the west (Tiksi settlement) and -13.4 C in the east (Chersky settlement). The permafrost samples of various age and origin, as well as soils buried in those sediments and burrows of fossil rodents, were selected for protozoological analysis....

Thermokarst Processes 1321 Thermokarst Subsidence

Thermokarst subsidence denotes a lowering of the ground surface following ablation of excess ice in permafrost. Ablation typically occurs by melting caused by heat conduction as the active layer deepens or surface water ponds. In permeable soils, however, it also results from heat convection by percolating rain or ground-water. The subsequent loss of excess water by drainage or evaporation allows the soil to consolidate and ground surface to subside. Subsidence is clearest where it is...

Physical Properties of Antarctic Soils and Permafrost

The physical properties of Antarctic soils and permafrost are known from numerous studies since the 1960s, but principally from those of Ugolini (1964), Claridge (1965), Campbell and Claridge (1975, 1987, 2006), Claridge and Campbell (1977), Bockheim (1979), Blume et al. (1997) and Campbell et al. (1998). The two main pedological processes that operate in Antarctic soils are oxidation and salinization. Coarse particle reduction takes place mainly at the soil surface, with surface clast size...

Design Approaches for Permafrost Regions

The impact of climate change on the integrity of structures built on permafrost has been widely discussed (US Arctic Research Commission 2003 ACIA 2005). The problem is twofold. Firstly, it is a prediction of behavior of existing buildings, and secondly, it concerns approaches to design for future conditions. Both are very difficult for design engineers to solve, because of uncertainties involved in existing climatic models and the wide range of results predicted by different climate change...

Implications for Global Change

Thus, warming in high latitudes may lead to an increased release of currently sequestered carbon through (i) Enhancement of temperature-controlled DOC production processes (ii) Raised precipitation, thereby increasing DOC mobilization from its large pool in the upper organic layer (iii) Introduction of a new source of DOC from older and deeper layers, caused by permafrost degradation. 20 40 60 80 DOC concentration, mg C l-1 Fig. 16.4 DOC concentrations in a soil profile (forest floor leachate...

Putative Roles of Cold Inducible Proteins in Low Temperature Growth

The temperature regulates the growth rate, the level of biosynthesis, metabolism, and survival (Price and Sowers 2004). Comparison of the proteomic profiles of different psychroactive bacteria grown at low temperatures involves the up-regulation of the similar proteins. Protein profiles of strains P cryohalolentis K5 and E. sibiricum 255-15 following cold adaptation showed overexpression of translation elongation factor Ts involved in gene expression, and F1 F0-type ATP-synthase B subunit...

Basin Thermokarst

Thermokarst basins are closed depressions formed by degradation of ice-rich permafrost. They are generally 0.5-20 m deep and 0.01-5 km in diameter, and many contain standing water (thermokarst ponds and lakes). The basins are initiated by factors such as water ponding or vegetation degradation. Thermokarst ponds or lakes sometimes develop at sites where thaw occurs beneath standing water, notably at ice-wedge intersections or in low-centred polygons, as well as under small streams (Dredge and...

Petroleum Releases to Unfrozen Active Layers

In permafrost-affected regions the thickness of the active layer will be minimal centimeters to a few meters, depending upon local conditions. The active layer begins to thaw during the spring snowmelt and continues to thicken until reaching maximum thickness in late August or September (Hinzman et al. 2005). As the active layer thaws a layer of water-saturated soil develops, which may be as thick as the entire thawed thickness. Thus, the downward flow of petroleum will be impeded due to low...

Permafrost

The most inhabited and ancient part of the cryosphere, permafrost, is defined as permanently frozen ground and underlies about a quarter of the Earth's land surface. This considerable frozen mass, up to several hundreds of meters deep, where microorganisms are adsorbed on organic or mineral particles, harbors a high level (up to dozen millions of cells per gram) of various morphological and ecological viable microbial groups that have survived under permafrost conditions since the time of its...

Groundwater Treatment

Various methods have been used, tested or proposed for the remediation of petroleum-contaminated groundwater in cold regions. These methods can be broadly divided into ex situ and in situ remediation approaches (Tables 19.3 and 19.4). The ex situ remediation methods that have been applied in cold regions are essentially variations of pump and treat, where the treatment component may include physical processes (e.g., oil-water separation, air-stripping), chemical processes (e.g., sorption to...

Active Method Accommodate Changes Associated with Permafrost Thawing Under Structure

At first glance, this method looks attractive in cases of degrading permafrost, but in fact it has very few successful applications. Permafrost thawing is accompanied by thaw settlement of soil and foundations if frozen soil is thaw-unstable. Thaw susceptibility of soil is determined by thaw strain the ratio of thaw settlement to thickness of the soil layer prior to thawing. It is important to define the borderline value of thaw strain below which soil can be considered as thaw-stable. One of...

Verification of Results

Since we cannot rule out that samples get contaminated on the basis of experimental setup, it is important to assess the authenticity using empirical tests. An independent line of evidence for authenticity of ancient DNA results is the application of relative rate analyses. One such approach the evolutionary rate test is an empirical test that exploits the temporal difference between related modern sequences and the very old DNA claims. The method infers the timing of the divergence between the...

Osmoresponse Of Terrestrial Environment

Azmi OR, Seppelt RD (1998) The broad scale distribution of microfungi in the Windmill Islands region, continental Antarctica. Polar Biol 19 92-100 Bab'eva EN, Sizova TP (1983) Micromycetes in soils of arctotundra ecosystem. Soil Sci (Pochvovedenie) 10 98-101 (in Russian) Bergero R, Girlanda M, Varese GC, Intili D, Luppi AM (1999) Psychrooligotrophic fungi from Arctic soils of Franz Joseph Land. Polar Biol 21 361-368 Callaghan TV (2005) Arctic tundra and polar desert ecosystems In Arctic climate...

Migration of Petroleum into Permafrost

Petroleum hydrocarbons have been measured at depths of meters in permafrost (Biggar et al. 1998 McCarthy et al. 2004) even though petroleum migration into permafrost should typically be minimal, due to high pore-ice saturations in the upper few meters of these frozen soils. Presence of petroleum hydrocarbons in both these cases was attributed to free-phase petroleum movement through interconnected air voids in the frozen soil. These air voids may result from unsaturated compacted soil, fissures...

Diversity of Viable Bacteria and Archaea

The catalog of viable Bacteria recovered from permafrost and associated environments, currently includes at least 70 genera (Table 5.2). Cultured isolates recovered from permafrost are capable of a wide range of metabolic processes including aerobic and anaerobic heterotrophy, chemolithoautotrophy, sulfate-reduction, methanotrophy, methanogenesis (Gilichinsky et al. 1995 Steven et al. 2006) and even phototrophy (Chap. 6). Both Gram-positive and Gram-negative cells are represented, and...

Retrogressive Thaw Slumping

Retrogressive thaw slumping is a slope failure characterized by thaw of exposed ground ice and slumping of thawed soil. Slumping usually starts where ice-rich permafrost is exposed by erosion, mass movement, forest fires, construction or mining (Burn and Lewkowicz 1990). Where the exposure reveals massive ice, large ice wedges or dense concentrations of segregated ice, slumping may quickly enlarge it to produce a steep or vertical headwall (1 m to > 15 m high) that overlooks a low-gradient...

Present Day Situation

Permanent and seasonal polar caps occupy vast territories, and are the obvious evidence of the Martian cryosphere (Hvidberg 2005). Seasonal caps represent the up to 2 m thick CO2 condensate, which drops out until approximately 60 latitude during the winter polar night in the corresponding hemisphere, and sublimates in spring and summer. In summertime at the poles, permanent caps remain consisting of water but because of the ellipticity of the Martian orbit, the southern summer is shorter, and...

Ex Situ Treatment of Groundwater

Most methods for ex situ treatment of hydrocarbon-contaminated groundwater at cold-climate sites are conventional methods of pump and treat that are commonly used by engineering firms at warmer sub-Arctic sites. For general information about these conventional pump and treat methods, the reader is referred to overviews provided by Nyer (1992), Eastern Research Group, Inc. (1996), and Cohen et al. (1997). Documentation of applications of pump and treat in cold regions has typically been in the...

Isolation and Identification

For isolation of photoautotrophic microorganisms, prolonged enrichments (8-18 weeks) of thawed but otherwise undisturbed permafrost samples under continuous illumination (1,000 lx) were applied. The enrichment cultures in BG11 (Rippka 1988), Bristol (Gollerbakh and Shtina 1969), BBM (Brown and Bold 1964) media were incubated at 4 and 20 C. Enrichments were re-examined weekly to document biodiversity (Table 6.1). Isolates were initially examined by measuring of the fluorescence excitation...

Physical Treatment Methods

Dig and haul is not a treatment method per se, but rather the practice of excavating contaminated soil and hauling it to an off-site location for incorporation with other contaminated soil or treatment. The practice can be performed year-round (excavator with frost bucket in winter), is routinely used in the Arctic and Antarctica where roads and infrastructure exist, and is expensive. Permitting may limit the practice in sensitive environments (e.g., tundra, tundra lakes or marshes, and Arctic...

Anammox in the Environment

The linkage of anammox activity with the removal of fixed inorganic nitrogen in natural systems was first confirmed in the Black Sea suboxic water column (Kuypers et al. 2003). Since then, anammox has been shown to be a significant contributor to nitrogen losses in a variety of environments, responsible for 19-35 of the nitrogen loss in an anoxic coastal bay (Dalsgaard et al. 2003) and the majority of N removal in one of the most productive regions of the world's oceans, the Benguela upwelling...

Anammox Physiology and Metabolism

All currently known bacteria capable of anaerobic ammonium oxidization belong to a deep-branching lineage of the order Planctomycetales with high genus level diversity (Freitag and Prosser 2003 Schmid et al. 2003). The evolutionary distance among the anammox genera is large (< 85 16S rRNA gene nucleotide identity), though they share the same basic anammox metabolism and cell structure. There are currently four Candidatus genera whose grouping is largely based on 16S rRNA sequences the...

Model Organism Psychrobacter

Among the microorganisms that have been recovered and isolated from Siberian permafrost samples, Psychrobacter species have remarkable capabilities at subzero temperatures which identify them as potential model organisms for the study of low-temperature adaptations relevant to inhabiting permafrost (Vishnivetskaya et al. 2000 Bakermans et al. 2003). These Psychrobacter species grow quickly at low temperatures, actively reproduce at -10 C, easily survive freeze-thaw cycles, and are tolerant to...

Control of Molecular Motion

Low temperatures decrease the energy of motion of molecules, leading to increased stability and rigidity. For example, as temperature decreases proteins become less flexible, membrane lipids become less fluid, and secondary structures of DNA and RNA become more stable. As a general mechanism, cold-adapted microorganisms increase the disorder within macromolecules to maintain fluidity or flexibility, and hence function at low temperatures (Feller 2007). In P. arcticus 273-4, a variety of...

Taxonomical Research

Flagelados Intestinales

We examined about 200 samples of Pleisocene and Holocene deposits, which were collected from 29 boreholes at a depth of 0.5-47 m, as well as from buried soils and the material of cryopedolith-located fossil rodent burrows. In the ice-complex sediments, viable protozoa were found in 25 of 125 samples (20 of total samples examined). Occurrence of viable protozoa was considerably higher in the buried soils (80 14 samples) and fossil burrows (100 12 samples) (Table 8.1). The protozoological...

Release and Chemical Composition of Riverine DOC 1631 Seasonality of Riverine DOC Export

Based on seasonal patterns of discharge and the chemical characteristics of DOC in subarctic rivers, there is a common division of annual hydrographs into spring flood, summer through autumn, and winter flow periods (Fig. 16.6). Although the start and duration of these periods may vary greatly among basins and annually, such separation is motivated by distinct changes of sources and flowpaths of water and DOC in riverine systems. Fig. 16.6 Dynamics of S18O in water, concentration of DIC, DOC...

Building Failures in Permafrost Regions

Deformations of buildings in permafrost regions are inexcusably numerous, especially in Russia. The percentage of dangerous buildings in large villages and cities in 1992 ranged from 22 in the town of Tiksi to 80 in the city of Vorkuta, including 55 in Magadan, 60 in Chita, 35 in Dudinka, 10 in Norilsk, 50 in Pevek, 50 in Amderma, and 35 in Dikson (Kronik 2001 ACIA 2005). Hundreds of buildings were demolished or went through serious reconstruction (Ilichev et al. 2003). There have been many...

Indirect Evidence for Subzero Microbial Activity

Although reported in occasional publications starting in the 1960s (see below), subzero activity remains a matter of serious doubt, and is not unconditionally accepted as a significant factor in ecosystem dynamics of boreal and polar regions. The majority of texts assume that subzero temperatures reduce the intensity of biological processes to a negligible level. The definition of psychrophiles is based on their upper temperature limit of 20 C (Morita 1975 Helmke and Weyland 2004), while the...

Life in Dark and Cold Ecosystems

While the mechanisms which protect bacteria against the adverse conditions that include oxidation, cooling, high osmolarity dehydration and starvation are well studied, our knowledge about adaptive and survival mechanisms of photoautotrophic microorganisms in cold and dark ecosystems such as permafrost remains limited. Obviously the upper soil and permafrost layers prevent photosynthetic activity of any chlorophyll-containing organisms. However, green algae and cyanobacteria do survive in the...

Bioaugmentation and Natural Attenuation

An interesting paradigm exists with bioaugmentation and natural attenuation (or intrinsic bioremediation) as soil treatment methods for cold regions. Bioaugmentation, while controversial and expensive, is being used because proponents report achieving cleanup in short order. On the other hand, there is a strong desire to use less expensive natural attenuation, despite knowing little about its viability in cold regions. It appears that irrespective of long-term treatment and liability,...

Methane Cycle in Permafrost Soils

Organic Matter Cycle

The carbon pool estimates for permafrost soils vary between 4 and 110 kg C m-2 (Schell and Ziemann 1983 Tarnocai and Smith 1992 Michaelson et al. 1996). These large variations can be attributed to different soil types (from mineral to peaty soils) and varying depths of measurement (from the upper few cm to 1 m depth). Permafrost soils can function as both a source and a sink for carbon dioxide and methane (Fig. 15.2). Under anaerobic conditions, caused by flooding of the permafrost soils and...

Slow Molecular Diffusion in Frozen Soil as Possible Restriction Factor

Pure ice does not allow gas diffusion that is why air entrapped in the Greenland and Antarctic ice has been used for chronological reconstruction of the Earth atmosphere (Brook et al. 1996). There are ice lenses in polar soils and subsoils which serve as barriers to gas diffusion. However, the bulk of permafrost and seasonally frozen soils represented by mosaic of frozen water, solid organo-mineral particles and fine network of gas-filled pores and channels should be conductive for gases and...

Advantages and Disadvantages of Various Methods for Detecting Microbial Activity

The list of available techniques is shown in Table 9.1. The rate of incorporation of labeled DNA and protein precursors (thymidine and leucine, respectively) is the most popular method for testing homogeneous frozen objects, such as sea and glacier ice, DNA (3H-thymidine) and proteins (14C-Leucine) Clear physiological and biochemical interpretation of data Can be combined with subsequent analysis of labeled constituents Disturbance of natural community by substrate addition and thaw-refreezing...

Passive Method Maintain Frozen State of Soil

This method is the main one used in the permafrost regions, but it was not fully appreciated or widely used until the 1950s after a long period of unsuccessful attempts to accommodate changes associated with permafrost thawing under structures. Numerous buildings on permafrost experienced substantial deformations because of thawing of permafrost and thaw subsidence of foundation bases. This has happened throughout the entire Russian permafrost region when methods based on accommodation of...