Cryosols

During the formative years of northern pedologic studies in Alaska, the term Arctic generally was reserved for the Brooks Range and land to the north. Some investigators, however, extended the definition to include some of the treeless sectors of western and central Alaska. Delineations generally were based on a combination of vegetation and temperature, plus the presence of permafrost. Permafrost is present in various patterns in virtually all of Alaska, except some land bordering the Gulf of Alaska (Brown et al., 1997). One rightfully could include as Arctic nearly all of Alaska, but, in this chapter, discussions are almost exclusively of the Brooks Range, Arctic Foothills, and Arctic Coastal Plain.

The Eurasian study and development of concepts of permafrost-affected soils began over a century ago, in two centers, Russia and Germany. In Russia, permafrost-affected soils cover about 65% of the total area. Pioneers of Russian soil studies were faced with Cryosols. Unfortunately, for a long period, the results of these soil studies were published only in Russian and poorly known elsewhere. And since there are several thousand Russian publications on permafrost-affected soils, for this paper we have analyzed only monographs and some principal papers.

Northern Canada, the vast, sparsely populated region of Canada affected by permafrost, encompasses about half (5 × 106 km2) of the country and includes the Arctic and Subarctic zones and portions of the Boreal zone. This region, which is composed of the Northwest Territories, Nunavut (formerly the eastern portion of the Northwest Territories), the Yukon, and the northern portions of most provinces, has a population density of only 2 people per hundred square kilometers.

Soil scientists developed basic concepts of the geography of Arctic and Antarctic soils about 20 years ago (Tedrow, 1977; Karavaeva, Targulian, 1977; Sokolov et al., 1982). They acquired abundant information on soils and soil-forming factors, studied the soils of the Antarctic circumpolar region in detail, and suggested zonal patterns for the region (Campbell, Claridge, 1987; Bockheim, Ugolini, 1990; Blume et al., 1997). Their findings contain many discrepancies, however, and they demand reinterpretation of the spatial distribution of soils at high latitudes of the Northern Hemisphere and comparative analysis of soil covers of the Arctic and Antarctic.

Permafrost, or perennially frozen ground, covers 9×105km2 or 55% of the landmass of Alaska. The continuous zone of permafrost encompasses the physiographic subdivisions of the Arctic Coastal Plain, the Arctic Foothills, the northern Norton Sound Highlands, and the Brooks Range. The zone of discontinuous permafrost encompasses the physiographic subdivisions of the Interior Alaska Lowlands, the Interior Alaska Highlands, the Alaska Range, the Copper River Plateau, the Kuskokwin Highlands, the southern Norton Sound Highlands, and the Western Alaska Coastal Plains and Deltas (Wahrhaftg, 1965; Péwé, 1975) (see Figure 2.2.1).

The Arctic, which covers approximately 30% (2,375,000 km2) of the land area of Canada, has a triangular shape. Its southern border is the Arctic tree line, the northern limit of trees. This border extends eastward from the Yukon-Alaska border (at approximately Lat. 69.5° N, Long. 142° W) across the middle of Hudson Bay (Lat. 57° N, Long. 80° W), to the Atlantic coast (at approximately Lat. 57.5° N, Long. 62° W). Its northernmost point is the northern tip of Ellesmere Island (Lat. 83° N, Long. 70° W).

Cryosols are soils whose formation is affected by permafrost within the soil control section. In this chapter we define Cryosol as in the Canadian System of Soil Classification (Soil Classification Working Group, 1998) and we use the taxa from that system to describe the nature and distribution of Cryosols in three non-Arctic regions of Canada. The boreal, subarctic, and cordillera regions extend across the North American continent (Figure 2.4.1) to incorporate the zone of discontinuous permafrost and the southern portions of the zone of continuous permafrost.

The Russian Arctic archipelagos, nearby isolated islands, and Spitsbergen are the main areas of High Arctic landscapes in the Eastern hemisphere. They include the large archipelagos of Novaya Zemlya, Severnaya Zemlya, and the New Siberian Islands, the northernmost but smaller Franz Josef Land archipelago, and several singular islands, including Wrangel, Vaigach, Belyi, Ayon, Kolguev Islands, and many smaller ones (Figure 2.5.1). Pedologists initiated their studies in the 1920s and visited almost all the archipelagos and large islands. These Russian northern islands later were mapped as part of a number of different small-scale soil mapping projects, compiled by extrapolating scarce field data, using remotely sensed images.

Northeast Eurasia is a vast, remote territory with the most severe climate in the northern hemisphere. The lowest recorded temperature in the hemisphere (−71°C) was recorded in northeast Eurasia at Oimyakon. In this region, the role of cryogenesis in soil formation and soil distribution is most pronounced.

This chapter summarizes the systematic information on the soils and soil cover of the Russian European North which before now has been known almost only by the Russian-speaking community of soil scientists.

Cryosols are widespread in the northern and central regions of western Siberia, from 73°30′ to 62° N latitude, where they formed under a vast spectrum of conditions, from tundra to taiga, including swampy areas (Figure 2.8.1). Between 62° and 60° N latitude, these soils occur only within the coldest ecotopes of forest areas. The features, diversity, and geography of Cryosols depend on both recent and paleoclimatic factors that control the presence and properties of permafrost (temperature, content of ice, depth, and water and heat regimes of the active layer).

Southern Siberia and the far eastern parts of Russia run west to east, from 49 to 55 (60)° N latitudes and 84 to 140° E longitude and to the extent of approximately 5000 km, from western Siberia to the Pacific coast, along the Russian-Mongolian and Russian-Chinese borders. This region includes the vast southern Siberian mountain systems of the Altay, the West and East Sayans, Tuva, the Baikal regions, and the part of the Russian far east called “Priamurye” (Figure 2.9.1).

Mongolia stretches for nearly 1200 km north to south and covers over 10 latitudinal degrees (from 52°04’N to 41°48’N), with forested mountains in the north and desert depressions in the south. Naturally, the latitudinal zonality influences the distribution of permafrost-affected soils; they decrease from north to south. Relevant literature (Melnikov, 1974; Lonzhid, 1966; Tumurbator, 1975, and others) describes geocryological conditions of Mongolia and provides information on historical records of studies, actual and paleocryological conditions, and the division of the area into geocryological regions.

Permafrost is defined as a thickness of soil or other superficial deposit, even bedrock, that remains frozen for consecutively two years or more (Muller, 1947). Permafrost, or perennially frozen ground, underlies 2.15x106 km2 or 22.4% of the territory of China (Qui and Cheng, 1995) and can be divided into two broad categories, high-latitude permafrost in northeastern China (0.38x106 km2) and high-altitude permafrost in the Qinghai-Xizang Plateau and some alpine regions in western and eastern China (1.76x106 km2) (Figure 2.11.1). The total area of soils affected by permafrost in China is third in the world, after Russia and Canada, but the area of high-altitude perennially frozen soils is the largest in the world.

Antarctica, with an area of approximately 14 million km2, is the world’s largest continent. The Southern Ocean, which extends from about the 40th parallel to the Antarctic Circle at 60° S, surrounds it. The continent is roughly circular, and its surface rises steeply from the coast to a vast interior ice-filled plateau.

Central Siberia is a vast area (about 4,000,000 sq. km) between the Yenisei and Lena rivers. It stretches from Cape Chelyuskin (77°43′N, 104°18′E) in the north to the foothills of Eastern Sayan, Baikal, and the Stanovoi ridges (52°N) in the south. This chapter also considers the mountainous Trans-Baikal region, to the southeast of Central Siberia, which usually is included in the physiographic province of the Southern Siberian Mountains.

Processes involved in soil formation (gley, podzolic, and metamorphic processes, leaching, accumulation and retention of humus, and others) are based on “elementary” physico-chemical soil transformations (phase transitions, surface interactions, transfer of mobile phases, etc.). In cryogenic soils, ice, which substantially modifies thermodynamic conditions, complicates physico-chemical processes and induces a characteristic set of specific indices. The soils inherit a thin-platy structure from the cryogenic texture (from ice lensing), the silty fraction predominates, fissuring forms are diverse, and contrasting distribution patterns of soluble components occur (Makeev, 1978).

Micromorphological analysis makes it possible to study the interrelationships between the various individual components, particles, and pores that make up sediments and soils.

Cryosols are soils whose development is affected by permafrost, ground that remains frozen for two or more years (ACGR, 1988). Cryosols develop both within the active layer, the surface layer of the ground above permafrost that freezes and thaws each year (Muller, 1947), and in the upper portion of the permafrost. For the requirements of classification, the control section for a Cryosol may be 1 or 2 m deep and must contain permafrost (Soil Classification Working Group, 1998; Soil Survey Staff, 1999).

The Transantarctic Mountains are the dominant physical feature of the Antarctic continent. Some 2500 km long and up to 100 km wide, the Transantarctic Mountains form an escarpment, throughout most of their length, comprised of crystalline basement rocks, chiefly granites, overlain by Devonian to Jurassic, predominantly sandstone sediments, with massive intrusions of Jurassic dolerites (Bradshaw, 1990).

Many soil researchers of the Antarctic (e.g., O’Brien, 1979; Campbell and Claridge, 1987; Bockheim and Ugolini, 1990) hold that no considerable chemical weathering and no new formation of minerals has taken place in soils of the Antarctic Desert and Tundra. They describe intensive changes in soil condition from cryoturbation and cryoclastic weathering but do not recognize a stronger influence of chemical weathering. However, pedologists from Central Europe assume that intensive cryoclastic weathering facilitates easier chemical weathering at low temperatures and thus allows a new formation of minerals (Kopp and Kowalkowski, 1990). Some even assume that, in many soils of Central Europe, brownification and clay formation mainly occurred under periglacial conditions (Kowalkowski and Borzyskowiski, 1973; Kopp et al., 1982).

The arid Cryosols form in a very low-energy environment. The prevailing temperatures are very low, mean annual temperatures being everywhere below freezing, and the active layer of the soil is only above freezing for a very short time (Campbell and Claridge, S. 3, Ch. 4)). Moisture availability is also very low, because for most of the time any moisture present is in the form of ice, while the absolute amount of water is also extremely low because of very low precipitation.

Soils of northern regions contain about 26% of the terrestrial C-stocks; the Arctic and boreal zones each hold about 12 to 13% (Post et al., 1982). Under the climatic conditions of the recent geological past, these regions have served as a sink for atmospheric carbon. Recent research efforts in Alaska have shown that tundra which has exhibited sink activity up to the 1970s has now, in the past decade of 1980 to the 1990s, reversed net C-flux activity and become a source of atmospheric carbon (Oechel et al., 1993).

Basic pools of organic matter in terrestrial ecosystems are phytomass, mortmass, zoomass, microbiomass, and soil organic matter (SOM). The phytomass includes the living organic matter of plants in the surface and ground spheres, whereas the mortmass is organic matter of dead standing and fallen trees and of the brushwood of lignified parts of plants, dead grass, litter, dead parts of mosses, and dead underground plant organs (Bazilevich, 1993). The phytomass or mortmass contains 2 to 4 times more organic matter than the zoomass and microbiomass, which are composed of the biomass of animals and microorganisms, respectively (Kovda, 1985). SOM is composed of humus and peat (Orlov et al., 1996). The SOM reservoir is the largest in Arctic and boreal ecosystems.

Recent literature regards organic matter and its accumulation as of minor importance to soil’s formation in Antarctica (Bockheim and Ugolini, 1990). This is probably why the global map of distribution of soil organic carbon leaves Antarctica completely white (Batjes, 1995). However, most of the recent data came from soils of dry valleys with a very low humus content (Campbell and Claridge, 1987; Claridge and Campbell, Section 4, Chapter 6). In contrast, Blume et al. (1997) showed that the carbon and nitrogen content of the top soils of the southern circumpolar region is much greater than expected (see also Blume and Bölter, 1993; Blume et al., 1996).

Despite the live-hostile climate in the Antarctic, soil formation processes, due to the accumulation of organic matter, are evident (Beyer et al., 1999). In the maritime Antarctic climate region, organic soils, mainly formed by debris of mosses and algae, are widespread (Campbell and Claridge, 1987) and mineral soils also contain huge amounts of soil organic matter (SOM) (Blume et al., 1996). In contrast, in the coastal regions of eastern Antarctica, only local patches of Gelic Histosols are associated with Leptic, Haplic, and Spodic Cryosols (Beyer et al., 1999).

Antarctica is a large, ice-covered continent, where soils are the exception. Less than 3% of the region is ice-free, and most of that is extremely cold and arid (Lewis Smith 1993a, b) most of the year. The environment severely limits soil organisms’ survival strategies and adaptive capacities. Nevertheless, several groups of soil-dwelling animals, plants, and microorganisms have settled in various niches of this continent.

Because of the prevailing low temperatures, low humidities, frequent freeze-thaw cycles, and salinity of the soil, the Arid Cryosols of the Transantarctic Mountains are generally unfavorable environments for plant and animal life. Nevertheless, careful examination of the soil shows that habitable niches do exist, and organisms have colonized the soil and radiated to fill most of them. Food chains have formed, and a relatively large number of organisms occur in a relatively simple ecosystem.

This chapter discusses: 1.the microclimatic differences and seasonal thawing dynamic of soils2.the dynamics of redox conditions and of the chemical composition of soil solutions3.the primary productivity of plant communities in separate elements of simplexes4.the connection between biodiversity and soil-vegetative cover in complex structures5.the possible influence of global climate changes on tundra soil cover and on primary productivity.

The Canadian System of Soil Classification (Soil Classification Working Group, 1998), Canada’s national system, classifies soils according to their measurable properties. The classification is hierarchical, having soil orders at the highest level and great groups and subgroups at lower levels. Families and series are also part of the classification.

Russia contains the world’s largest areas of permafrost and has a long-term tradition of soil classification. The traditional Russian genetic classification approach has been revised to change the relative role of ecology and soil properties. Still, most Russian classifications give priority to soil genesis and a subordinate place to arbitrary, rigid class definitions. Thus, after highly formalized world soil classification systems were adopted (firstly, US Soil Taxonomy), a gap between them and the Russian school appeared, and it persists.

Although Soil Taxonomy attempts to account for all the soils in the world, taxa for permafrost regions of the world did not receive adequate attention until recently. This can be attributed to the low human population of permafrost regions and the limited suitability for traditional cultivated agriculture.

The World Reference Base for Soil Resources (ISSS Working Group RB, 1998) classification includes permafrost-affected soils in three groups. The first is the Histosol major soil group, which includes both perennially frozen (Cryic, Glacic and Gelic lower-level units) (ISSS Working Group RB, 1998, pp. 13, 76) and unfrozen organic soils. The second is the Cryosol major soil group, which includes all of the perennially frozen mineral soils that have a cryic horizon (ISSS Working Group RB, 1998, pp. 14, 30). The third includes those soils in the Leptosol, Fluvisol, Solonchak, Gleysol, Podzol, Planosol, Albeluvisol, Umbrisol, Cambisol, Arenosol, and Regosol major soil groups (ISSS Working Group RB, 1998, pp. 76–78) that have permafrost at depths of 100 to 200 cm.

There are two centers of forage production in European Russian tundra, one near Murmansk on the Kola Peninsula and the other around Vorkuta, in the northeast of European Russia. Tundra on the Kola peninsula has no permafrost but around Vorkuta has massive-island permafrost. Vorkuta is a center of a large coal basin where coal has been developed since the 1930s. During the Soviet era, agricultural development of tundra lands was considered expedient around large towns (Vorkuta had pop. 101,000 in 1981; Murmansk, 394,000 in 1982) to supply them with food. Agriculture there included dairy husbandry, forage production, and greenhouse vegetable production.

The largest environmental concern facing the mining industry today is the occurrence of dissolved heavy metal contaminants and acidic effluents caused by sulfide oxidation (Paktunc, 1999), generally referred to as acid mine drainage (AMD). Numerous abandoned, operating, and proposed metal mines exist in permafrost-affected regions, and disposal of mine waste and AMD occur at several mine sites in the Arctic. Mine tailings result from the processing of ore and usually are transported to nearby disposal areas. Pollution in most cases spreads to the surroundings by acidic drainage to local watershed stream systems and marine environments.

Cryosols of the Transantarctic Mountains region of Antarctica are an important part of one of the earth’s more extreme ecosystems. They have evolved in an environment dominated by extremely low temperatures, severe aridity, and the absence of a significant soil biological regime.

The study of Antarctic soils is comparatively new, spurred in the late 1950s by the growing interest in earth and other sciences in Antarctica. Curiosity drove initial investigations, and the questions were whether soils actually existed there and, if so, what their properties were and what processes operated (McCraw, 1960; Ugolini, 1963; Claridge, 1965; Campbell and Claridge, 1966; Claridge and Campbell, 1968; Tedrow and Ugolini, 1966). As glaciological investigations intensified, weathering relationships became valuable for establishing glacial chronologies (Calkin, 1964; Ugolini and Bull, 1965; Everett, 1971; Campbell and Claridge, 1975; Bockheim, 1978, 1982) and attention focused on the spatial and temporal differences in and the broader significance of soil properties (Campbell and Claridge, 1987).