Natural Features

M. V. MURATOV, V. M. TSEISLER, E. S. CHERNOVA, and E. A. USPENSKAIA

V. M. TSEISLER

I. I. SPASSKAIA

G. A. MIRLIN

T. K. ZAKHAROVA

A. A. BORISOV

A. I. POPOV

A. A. SOKOLOV

D. IA. RATKOVICH

Bibliography

The shores of the USSR are washed by 12 seas, belonging to the basins of the Atlantic, Arctic, and Pacific oceans. In addition, there are two inland seas (see Table 9).

Far Eastern seas. The Far Eastern seas—the Sea of Japan, the Sea of Okhotsk, and the Bering Sea—are marginal seas, occupying an area of about 5 million sq km. The relief of the floor is characterized by deep-water basins, with predominant depths of 3,500–4,000 m, and, in the north, by vast shallow regions of the continental shelf. The morphostructures of the transitional zone, including the basins of the marginal seas, island arcs, and deep ocean trenches, are most extensively developed. Individual ridges and rises dot the flat or rolling surface of the floor of the marginal seas, which has subsided to a depth of 300–400 m.

The region of the Far Eastern seas is marked by high seismicity and by modern volcanic activity. The influence of the Asiatic continent and the relatively unobstructed connection with the Pacific Ocean determine the climatic and hydrologic features of the seas. The seas are rich in fish and other marine products. Important waterways linking Vladivostok with many Soviet and foreign ports pass through the Far Eastern seas. The principal ports are Vladivostok, Nakhodka, Magadan, Petropavlovsk-Kamchatskii, and Korsakov (on the Island of Sakhalin).

Arctic seas. The arctic seas—the Chukchi, East Siberian, Laptev, Kara, Barents, and White seas—occupy a shelf measuring up to 1,300 km in width. They are shallow seas: the edge of the shelf is generally at a depth of about 500 m. The continental slope has depths ranging from 180 to 3,000 m, with several levels of inclined, terrace-like plains. The arctic seas have a total area of more than 4.5 million sq km. They are connected to one another by straits, the most important being the Karskie Vorota, Vil’kitskii Strait, Dmitrii Laptev Strait, and Long Strait. They receive a number of large rivers, including the Lena, Enisei, Ob’, and Pechora, and serve as a means of communication between the coastal regions and the interior of the country.

The climate is harsh, and the arctic seas are ice-bound most of the year, except for the southwestern part of the Barents Sea, which remains ice-free year-round because of the incursion of warm Atlantic waters. The Northern Sea Route passes through the arctic seas. The principal ports are Murmansk (which is ice-free), Arkhangel’sk, Belomorsk, Kern’, Kandalaksha, Mezen’, Dikson, Nordvik, and Tiksi. The White Sea-Baltic Canal connects the White Sea with the Baltic Sea and, through the V. I. Lenin Volga-Baltic Waterway, with the Sea of Azov and the Black and Caspian seas.

Baltic Sea. The Baltic Sea occupies the continental shelf and has an average depth of 71 m. It has many islands, most of which form island groups. The fauna is characterized by a mixture of marine and freshwater species, and much fishing is carried on. The sea is a major transportation artery, linking the USSR with many foreign ports. It is linked with the Volga through the Volga-Baltic Waterway and with the White Sea through the White Sea-Baltic Canal. The principal ports are Leningrad, Tallinn, Riga, Liepāja, Klaipeda, and Kaliningrad. The Baltic is famous for its resorts.

Southern seas. The southern seas—the Black Sea, the Sea of Azov, and the Caspian and Aral seas—occupy an area of approximately 900,000 sq km and are either very deep (more than 1,000 m) or very shallow (less than 15 m). Because of their location and hydrologic regime, they are classified as intracontinental seas; they have limited connection with neighboring seas and, through them, with the ocean.

The Sea of Azov occupies the Scythian Platform and the fore-deep of the Crimean-Caucasian folded region. Its floor is a flat aggradational plain that is inclined to the south, and its depths are only a few meters.

The shelf of the Black Sea, which varies from 1 to 200 km in width, occupies a vast area in the north. The northwestern part of the sea is a shallow plain, with traces of ancient Dnieper channels, sandbars, spits, and ridges. The continental slope descends to a depth of 1,800–1,900 m; south of the Crimea, there are terraces and scarps of fault origin. The floor of the deep-water basin (more than 2,000 m) is flat. About one-fourth of all the import shipping of the USSR and one-half of all the export shipping pass through the Black Sea.

The principal ports on the Black Sea are Odessa, Il’ichevsk, Nikolaev, Kherson, Sevastopol’, Kerch’, Novorossiisk, Poti, and Batumi; those on the Sea of Azov are Zhdanov, Taganrog, Eisk, and Berdiansk. Numerous resorts line the Black Sea coast.

The Caspian and Aral seas are isolated bodies of water with no outlets. The Aral Sea occupies the most subsided part of the Turan Plate. The floor of the sea, which is flat, is located entirely in the region of shelf depths.

The Caspian Sea is divided according to relief into three parts: the shallow (4–8 m) northern part, the central part (depths to 788 m), and the deep (more than 1,000 m) southern part. The northern part and significant parts of the central and southern parts are occupied by aggradational, abrasion-aggradational, and denudation plains of the shelf. The relief of the southern basin is complicated by a system of underwater ridges, and the southern and southeastern margins border on the continental slope. The Caspian Sea, located in the lowest part of a vast region with no outlet, is completely cut off from the world ocean and has an extremely unstable hydrologic regime. The great variability of its water balance and the considerable long-term variations in water level are a result of an intricate complex of climatic, hydrologic, and geological processes within its enormous drainage area. The Caspian Sea is connected by a system of internal waterways with the Sea of Azov and the Black and Baltic seas. The principal ports are Baku, Astrakhan, Krasnovodsk, Makhachkala, and Shevchenko.

(For information on marine resources, see above: Mineral resources; see below: Plant resources; and Animal resources.)

Bibliography

General features of the soil cover. The changes in space and over time in the soil-forming factors, such as climate, relief, parent rock material, and vegetation, and the resulting differences in the development of the soil cover in individual regions have led to the formation of various kinds of soils in the USSR. The geographic distribution of soils is governed by a number of regularities, the most clearly marked being latitudinal (lateral) zonality—the succession of different soil types from north to south, more precisely from northwest to southeast, as a result of variations in climatic conditions (heat and moisture) and vegetation.

On the East European Plain a succession of zones of tundra, podzolic, gray forest, chernozem, chestnut, and brown semidesert soils is observed from north to south. Most of the zones are subdivided into subzones, where definite soil subtypes predominate. For example, the chernozem zone is divided into subzones of podzolized, leached, typical, common, and southern chernozems. Soils within the zones and subzones also have their own characteristic features, reflecting the different climatic conditions, such as the length of the cold and warm seasons and the degree of summer warming and winter cooling in the eastern and western parts; this has made it possible to identify various soil provinces. For example, the Ukrainian chernozems have thick humus horizons and a low humus content in the upper part of the soil profile, while the chernozems in the Volga Region, particularly in the Cisurals, have much thinner humus horizons but greater accumulations of humus in the upper layers.

Latitudinal zonality is clearly expressed on the East European Plain and Western Siberian Lowland, where the soils formed on loose, deeply weathered Anthropogenic parent rocks. In the warmer (western) part of the East European Plain, however, podzolic brown earths and brown forest soils are frequently encountered in the zone of podzolic soils. Bog and waterlogged soils are widespread in the forest zone of the poorly drained Western Siberian Lowland; saline soils and solonetzes are common in the steppe zone.

East of Transbaikalia, the soils form primarily on weakly weathered detrital rocks; in vast areas they form under the influence of permafrost. The distinctive and highly intricate structure of the soil cover here has been determined by the type of parent material, the different heat and, in particular, water regimes resulting from the monsoon circulation of the atmosphere, and the mountainous relief. Soil zonality is less clearly marked. Frigid taiga soils predominate in vast regions of Central and Eastern Siberia. Drier fine-grained soils occur in the enclosed lowered plains and basins, for example, the pale yellow soils of the Yakut Basin and the chernozems of the Minusinsk and Kana basins. Because of a relatively warm and humid climate, the southern part of the Far East has extensive areas of wet podzolic brown earths. Unique ochreous soils have developed on the young volcanic soil-forming rocks of Kamchatka. Stony soils are characteristic of Kazakhstan, where the soils in extensive areas formed on dense parent material.

The regularities of soil geography in mountain regions are determined by altitudinal (vertical) zonality—the succession of different soils from the foot of the mountains to the peaks caused by a change in climate. In the western part of Transcaucasia, for example, zones of yellow earths, red earths, brown forest soils, and mountain meadow soils can be traced from the foot of the mountains to the peaks. In the Urals and the Altai, the sequence is chernozems, gray forest soils, mountain podzolic soils, mountain meadow soils, and mountain tundra soils. Submontane zonality, usually related to the increased precipitation on submontane plains in close proximity to the mountains, is very important. In Ciscaucasia this is expressed in the sequence of carbonate, typical, and leached chernozems, while in the Cisurals, it is expressed in the sequence of chernozems and gray forest soils. On the submontane plains of Middle Asia, desert soils are supplanted by light and conventional sierozems.

Each zone and subzone, which has been named after a predominant soil, also contains other soil types and subtypes. For example, bog podzolic and bog soils are commonly found among podzolic soils, meadow chernozems, and meadow soils; in some places, solonetzes frequently occur among chernozems, as well as among chestnut and brown semidesert soils. Such alternations create different soil combinations, which, when taken together, determine the soil structure. Individual structures differ with respect to the nature and degree of contrast in the properties of the constituent soils, the ratio of their areas, and the size and shape of the similar sectors that form the different combinations. Within the soil groupings there are soil complexes, in which small patches (a few dozen square meters in area) alternate, as well as combinations and mosaic surfaces, whose areas are measured in terms of hectares and tens of hectares. The structure of the soil cover largely determines both the possibility and effectiveness of soil use. Thus, some soil complexes cannot be cultivated without expensive and complex reclamation work. Combinations of small soil mosaics make it very difficult to establish extensive plowed areas.

The structure of the soil cover depends on zonal bioclimatic conditions, topography, and the parent material. Zonal conditions cause the development of a more intricate soil structure with the extensive distribution of soil complexes in the zone of tundra, chestnut, and brown semidesert soils. Mosaics of podzolic, bog podzolic, and bog soils are clearly expressed in the zone of podzolic soils in the northwestern part of the European USSR, a region of young glacial topography. In Central Siberia the alternation of fragmented and finely fragmented parent material produces complex and patterned surfaces of dry frigid soils and icy frigid soils, which are usually overmoist. On the Central Russian Upland, the extensively developed network of ravines and gulleys causes combinations of uneroded chernozems and chernozems eroded to varying degrees. The subsided relief of the southern Ukraine and the forest-steppe zone of Western Siberia, with many small downwarps and fissures, produces circular-spot combinations of chernozems, meadow soils, solodi; and solonetzes.

Four types of soil structures are identified on soil maps: soil complexes, for example, solonetzes with brown semidesert soils; combinations in which the components are of approximately equal ratio, for example, frigid taiga and bog soils; combinations in which one type of soil predominates, for example, yellow frigid taiga soils with bog soils and solodi; and uniform blocks, for example, gray forest soils.

The structure of the soil cover of soil zones in the mountains is determined by the elevation, the steepness and exposure of the slopes, the properties of the parent material, and the degree of erosion. In moderately humid mountain regions, the influence of slope exposure on the character of the soils acquires considerable importance and gives rise to a special type of soil cover known as exposure-differentiated. In mountain regions with excess moisture, the structure of the soil cover is very simple.

Mountain soils generally differ from the soils of the plains in the amount of detrital material, the thinness of the soil profile, and the greater compactness of the soil cover. Nonetheless, most mountain soils can be classified in terms of the corresponding soil types developed on the plains, for example, mountain chernozems and mountain podzolic soils. However, certain kinds of soils found in the mountains are rarely encountered on the plains. The most widespread of such soils are Alpine meadow, mountain meadow steppe, and mountain podbur soils. Alpine meadow soils form in high mountains with a humid climate. They have a humus-rich (up to 20–30 percent) soddy horizon, beneath which is a transitional horizon and then the parent material. Such soils are acid in reaction and are used for summer grazing. Mountain meadow steppe soils form in drier middle-altitude and high mountain areas. They differ from mountain meadow soils in a lower humus content and a reaction that is nearly neutral. In level areas they are used for summer grazing. Mountain podburs develop in humid, cold forested mountain regions. They are very acid, and their upper horizons are rich in tongued humus. The principal areas of mountain soils are forested. Many have high natural fertility, but great care must be taken when farming such soils because of the rapid development of erosion, which can completely wash away loose layers.

The plains soils of the USSR are grouped into two major groups: leached and unleached.

LEACHED SOILS. Leached soils develop under tundra, forest, and meadow vegetation, where moisture in the form of atmospheric precipitation and the like exceeds the potential for evaporation. As a result of the predominantly descending flow of moisture created in such a case, various water-soluble salts, such as chlorides, sulfates, and carbonates, that are contained in the soil-forming rocks and that arise in the process of soil formation are removed from the soil, which then becomes acid.

Tundra gleys. Tundra gleys are characterized by a surface peat horizon. The lower layers are characterized by very mobile forms of humus and by strong gleying, which imparts to the soil profile a grayish color, sometimes with rust-colored mottles.

Podzolic soils. Podzolic soils form under coniferous and mixed forests. Their profile is sharply delineated; the middle and lower (illuvial) horizons are rich in silt, while the upper (eluvial) horizons have little silt. Podzolic soils are divided into three subtypes: gley podzolic soils, with a gleysolic upper layer (they usually form in areas with the wettest conditions, in the northern taiga); podzolic soils proper, with the most typical profile (in the central taiga); and sod podzolic soils, with a clearly marked humus horizon, containing 1–6 percent humus (in the southern taiga). Adequate moisture and good responsiveness to fertilizer make it possible to use podzolic soils, primarily sod podzolic soils, extensively for grains, forage crops, and potatoes and other vegetables. Podzolic soils, which require liming, are the principal cultivated soils of the Nonchernozem Zone.

Podzols. Podzols develop on poor sandy soil-forming rocks. They differ from podzolic soils in the character of the illuvial horizon. The illuvial horizon of podzols contains iron, aluminum, and, frequently, humus but no silt.

Bog podzolic soils. Bog podzolic soils are found among podzolic soils and podzols. In general, they retain the structure and properties of the two, but as a result of increased moisture they take on a number of the properties of bog soils, such as gleying and a peaty upper horizon.

Sod coarse humic soils. Sod coarse humic soils are found under the grassy and scrub-grassy forests of Kamchatka and the Kuril Islands. The upper horizons are rich in humus (5–9 percent), and tongued humus occurs in the middle and even lower horizons. The mineral content changes little throughout the soil profile.

Frigid taiga soils. Frigid taiga soils are associated with a cold, sharply continental climate and occur in the light-coniferous taiga of Siberia. The permafrost horizon lies at a depth of 1–1.2 m. Various traces of permafrost phenomena are observed in the profile: the sorting of coarse-grained material, the shifting of soil masses, and fissuring. Frigid taiga soils have a significant humus content, as much as 6–7 percent. Agricultural development is fraught with difficulties.

Gray forest soils. Gray forest soils are widely distributed in the zone of deciduous, primarily broad-leaved, forests. They combine the characteristics of podzolic soils (silt-poor upper horizons and silt-rich lower horizons, acid upper horizons) and steppe chernozem soils (clearly developed textured upper humus horizon, saturation with bases, and frequent presence of carbonates in the lower horizons). Such soils are fertile and are used extensively for grains, forage crops, potatoes and other vegetables, and industrial and other crops.

Brown forest soils. Brown forest soils form on rich, frequently detrital, parent material under broad-leaved and southern coniferous forests in the Carpathians, the Crimea, the Caucasus, and the southern part of the Far East. Clay minerals and iron oxides accumulate in the profile, imparting a brown color to the soils. The soils, which range from slightly acid to acid in reaction, are rich in humus, which constitutes 6–10 percent of the upper horizon. Brown forest soils respond well to fertilizers and are used in agriculture.

Podzolic brown earth and brown forest surface gley soils. Podzolic brown earth and brown forest surface gley soils develop on comparatively poor, deeply weathered loam and clay rocks among brown forest soils. They occupy the flattest relief elements and differ from other soils in a silt-rich illuvial horizon that retains sediment, as a result of which the upper horizon is waterlogged to varying degrees. Such soils are extensively cultivated, but they must first be drained and fertilized.

Chernozem-like gleys. Chernozem-like gleys form under the meadows in the lowlands along the Amur River. They have a thick humus horizon, containing 7–8 percent humus, whose lower part is gleyed. They are waterlogged as a result of groundwater and atmospheric precipitation. They are extensively used for rice, soybeans, wheat, and potatoes and other vegetables, but they require draining.

Yellow earths. Yellow earths form under humid subtropical forests in the Western Transcaucasus and the Lenkoran’ Lowland on relatively acid parent material. They contain relatively high amounts of iron oxide, considerable silt, and 3–3.5 percent humus. They are acid in reaction. Podzolic yellow earth and waterlogged gley podzolic yellow earth soils are found along with yellow earths on the relatively poor loams and clays that occupy flat plains. All these soils are used for subtropical crops, such as tea and tung. When limed and fertilized, they produce high yields.

Red earths. The red earths, which occur in the western part of Transcaucasia, form under the same conditions as the yellow earths and differ only with respect to the parent material (primarily neutral igneous rocks). The content of humus is high, amounting to 5–6 percent in the upper horizons and gradually diminishing lower in the profile. The red earths are rich in aluminum and iron oxides and have texture and other favorable physical properties. They are used for subtropical crops but require liming and fertilization.

Sod carbonate soils. Sod carbonate soils form under forests on carbonate-rich parent material. The largest areas with such soils occur in the Baltic Region and in Leningrad, Novgorod, and Perm’ oblasts. As a result of the conditions of formation, sod carbonate soils are neutral, have a high humus content (6–15 percent) and good structure, and are often quite stony. They are used extensively in farming.

Sod gleys. Sod gleys, which are similar to sod carbonate soils, develop under the influence of hard (calcium-rich) groundwater close to the surface.

Bog soils. Bog soils occupy significant areas, primarily in Western Siberia and in the northern part of the East European Plain; they also occur in Central and Eastern Siberia and in the Far East. They remain excessively wet throughout the year. They are subdivided into peat bog soils, with a thick surface horizon of peat; peat gley bog soils, in which the peat horizon is underlain by a gleysolic mineral horizon; silt bog soils, in which the silt horizon is a mineral mass mixed with decomposed organic matter that is replaced by gleysolic mineral matter; and meadow bog soils, in which the upper soddy mineral gleysolic horizon is replaced by a mineral gleysolic horizon. The humus content reaches 30 percent. The reaction varies from acid to alkaline. Peat and peat gley bog soils are subdivided into upper types, which are very acid and extremely poor in plant nutrients; lower types, which are neutral and rich in plant nutrients; and transitional types. Drainage and cultivation, which are done primarily on peat and peat gley bog soils, make bog soils suitable for farming.

UNLEACHED SOILS. Unleached soils develop when the potential for evaporation exceeds moisture (for example, precipitation). Simple salts are not washed out of the soil profile but accumulate at a certain depth. Unleached soils are neutral or alkaline in reaction.

Arctic soils. Arctic soils (arctic deserts on the islands of the Arctic Ocean) are thin and neutral, sometimes carbonate or even salinized. They are frozen most of the year, thawing out to small depths for only one or two months.

Pale yellow frigid taiga soils. Pale yellow frigid taiga soils occur in the driest regions of the light-coniferous taiga (central part of Yakutia). The upper part of the soil profile is neutral, while the lower part is often carbonate. The upper horizons contain 2–3 percent humus. The relatively warm summers make it possible to use these soils in agriculture.

Chernozems. Chernozems formed under the steppe and forest-steppe vegetation of the southern part of the East European Plain, Western Siberia, North Kazakhstan, and the basins of the southern part of Central Siberia. They have a thick (30–140 cm), well-structured humus horizon, with 4–10 percent humus, a horizon of carbonate accumulation, and, in arid regions, a gypsum horizon. Mycelial-carbonate chernozems from the Azov and Cis-caucasian regions, which form in areas where winters are warm and the soil does not freeze, are distinguished from chernozems that develop when winter temperatures are below freezing. Depending on moisturization, chernozems are subdivided into podzolized, leached, and typical chernozems (in the forest-steppe) and into common and southern chernozems (in the steppe). They range from slightly acid to slightly alkaline in reaction. They are very fertile and almost all are in agricultural use. Their productivity is limited by frequent droughts. Irrigation makes it possible to produce sustained yields of grains, sugar beets, sunflowers, and the irrigated farming of grains, melons, and other crops.

Chestnut soils. Chestnut soils formed under dry steppe vegetation in the southern Ukraine, Lower Volga Region, Kazakhstan, and Siberia. They differ from chernozems in a lower humus content (2–5 percent), thinner humus horizon (15–50 cm), and thinner carbonate and gypsum horizons. They frequently contain solonetzes, are alkaline in reaction and compacted, and swell significantly when wet. They are subdivided into dark chestnut soils, which occur in the wetter regions; chestnut soils; and light chestnut soils, which occur in the drier regions. Much of the areas with dark chestnut and chestnut soils are cultivated. Their productivity is limited by frequent droughts, and consequently the cultivation of crops, particularly grains, vegetables, and melons, often necessitates irrigation. Light chestnut soils are used primarily for hay production and for grazing.

Brown semidesert soils. Brown semidesert soils are found in the semideserts of Kazakhstan. They contain 1.5–2.5 percent humus in the upper horizon and are frequently alkaline in reaction. Carbonates and gypsum occur close to the surface. Brown semi-desert soils are used for grazing, hay production, and the irrigated farming of grains, melons, and other crops.

Gray-brown desert soils. Gray-brown desert soils are found in Kazakhstan, Turkmenistan, Uzbekistan, and Tadzhikistan. They accumulate less than 1 percent humus. The upper layers contain carbonates, and the gypsum layer lies at depths of 20–40 cm; still deeper are chloride and sulfate salts, which are toxic to plants. As a rule, the soils are alkaline. They are used for irrigated farming (cotton, alfalfa, vegetables, fruits) and for grazing.

Cinnamon and gray-cinnamon soils and sierozems. Cinnamon and gray cinnamon soils and sierozems occur in the dry subtropical regions of the eastern part of Transcaucasia and in the submontane and foothill regions of Middle Asia. The middle part of the soil profile is rich in clay particles (the clay accumulation horizon). Cinnamon soils develop under drought-resistant woody and scrub vegetation. They are characterized by a well-structured humus horizon, a dense clay horizon, and an illuvial horizon. The humus content is 5–9 percent. Cinnamon soils are used extensively for grapes, fruits, and grains.

Gray-cinnamon soils, which are found primarily in the eastern part of Transcaucasia, formed under grassy and phryganoid (thorny scrub, subshrub, and grassy) vegetation. They are low in humus (2–4 percent) and contain carbonates in the surface layer; gypsum and easily dissolved salts occur at shallow depths. Gray-cinnamon soils are used for cotton and grains, as well as for orchards and vineyards, which require irrigation.

Sierozems form under subtropical semidesert vegetation, primarily on the submontane plains of Middle Asia. The humus horizon is light gray and contains 1.5–4.5 percent humus. Beneath it is a compacted illuvial carbonate horizon, below which is gypsum-containing bedrock; easily dissolved salts occur at depths of 1.5–2 m. The surface layer is carbonate. The accumulation of clay in sierozems is less marked than in cinnamon and gray-cinnamon soils. Large areas of sierozems, which are for cotton, fruits, and other crops, are irrigated.

Meadow chernozem, meadow chestnut, meadow brown, and meadow sierozem soils. Meadow chernozem, meadow chestnut, meadow brown, and meadow sierozem soils are found among chernozemic, chestnut, and other soils, from which they differ in higher moisture (groundwater and, less often, surface water); moreover, they are often gleysolic and sometimes have more humus. They are used extensively for forage crops, vegetables, and other crops.

Meadow soils. Meadow soils develop in areas where the groundwater is close to the surface. Two horizons are identified, the upper soddy horizon, with up to 6–10 percent humus, and the horizon that is transitional to the gleysolic bedrock. Meadow soils are used primarily for hay production and grazing; they are sometimes tilled.

Solonchaks, solonetzes, solodi, takyrs, and takyric soils. Solonchaks, solonetzes, solodi, takyrs, and takyric soils form the group of saline soils. Solonchaks contain more than 1 percent water-soluble salts in the surface layer, which is usually associated with the presence of groundwater at a shallow depth. Proper irrigation and flushing and the establishment of artificial drainage to lower groundwater level make it possible to use solonchaks in agriculture.

Solonetzes, which are most extensive in dry steppes and semideserts, form primarily when solonchaks are desalinized. They are strongly alkaline in reaction; they are compacted when dry and swell when wet. Crops can usually be grown only after soil improvement, for example, the application of gypsum and deep cultivation.

Solodi develop primarily when solonetzes are desalinized and desolonetzized under conditions of increased surface moisture. They are found in flat, enclosed “wet” low areas amid steppe and forest-steppe soils. The upper horizons are acid. Improvement through the regulation of the water regime and alteration of the physical properties is essential for agricultural use.

Takyrs are primarily soils of the flat clay depressions of the desert zone, which are occasionally watered by flash floods and heavy rains. After the water evaporates, the surface layer of the takyr cracks to a depth of 8–10 cm, forming polyhedral parquetlike patterns. Beneath the layer is an almost unchanging saline bedrock.

Takyric soils resemble young floodplain soils and takyrs. They occupy young river plains that have only recently ceased acting as floodplains.

Floodplain (alluvial) soils. Floodplain (alluvial) soils form floodplains that are inundated by flood waters. They are stratified and frequently contain buried humus horizons. In wet regions they are noncarbonate and nonsaline and often acid in reaction, and in dry regions they are usually carbonate and neutral or alkaline in reaction. Bog soils sometimes occur among floodplain soils. Floodplain soils are fextremely fertile and are used for hay production and grazing, as well as for vegetables, forage crops, rice, and other crops.

The USSR has enormous soil resources. The most extensive areas of highly fertile chernozems and meadow chernozem soils in the world are located in the USSR, totaling 168.4 million hectares (ha), or about 8 percent of the USSR’s total soil area. The chernozems, as well as the dark chestnut, chestnut, and gray forest soils, form the basis of the country’s agricultural land. The sod podzolic soils are also of agricultural importance. Tundra, gley podzolic, and frigid taiga soils, which amount to about 340 million ha, or more than 15 percent of the total area, are not cultivated, since the heat resources in the areas where they occur are extremely inadequate for farming; the soils of mountain regions with unfavorable topography are also not used.

In semidesert and desert regions, light chestnut, brown semidesert, gray-brown, sierozem, and gray-cinnamon soils form a considerable part of the land surface, more than 270 million ha, or more than 12 percent, and agriculture without irrigation on such soils is extremely unproductive. Many soils in these regions, such as the takyric soils, takyrs, solonchaks, and solonetzes, are salinized and require other methods of improvement in addition to irrigation. Bog and waterlogged soils, which must be drained before they can be tilled, occupy more than 160 million ha, or about 8 percent. Sands and sandy and stony soils, which are also unsuitable for agriculture without expensive reclamation work, constitute more than 150 million ha. Thus, although the land suitable for agriculture is quite extensive, it constitutes a smaller proportion of the country’s total area than in many other countries. The calculation of areas of different soil types and subtypes (see Table 10) and soil zones and subzones (see Table 11) carried out by the Soil Institute provide an idea of the soil resources of the USSR and their use.

In different soil zones and subzones different proportions of the land have been brought into use. In the zone of gray forest soils and the subzones of podzolized, leached, and typical chernozems, about 48 percent of the total land has been put to agricultural use and 63 percent of the chernozems. These figures constitute the maximum possible land that can be under agricultural development here, since the area occupied by populated points, industrial enterprises, and roads, as well as unsuitable land, such as ravines, gulleys, and areas with stony soils, is quite considerable. The zones of gray forest and chestnut soils are also close to maximum use; of the total arable agricultural land in the USSR, including cropland, idle land, and land under perennial plantings, 76 percent is located in these zones and the chernozem zone owing to the high fertility of the soils in the zones, favorable topography, which permits the use of modern machinery, and the relatively favorable climate, requiring no irrigation or drainage. However, inadequate precipitation in these zones and frequent droughts make it difficult to obtain high sustained yields. There-fore, the technology of growing crops must be directed at accumulating and preserving moisture in the soil, and consequently the expansion of irrigated areas is very important.

The subzone of sod podzolic soils, which has an adequately moist climate that is cooler than the chernozem climate, is the site of a large agricultural region, which includes the Nonchernozem Zone of the European part of the USSR, the southern taiga regions of Western Siberia, and the southern part of the Far East and which accounts for 16.5 percent of the total arable land in the USSR. Sod podzolic soils are acid in reaction; they are not as rich in nutrients as gray forest, chernozem, and chestnut soils, and their physical properties are not as good. However, because of the available moisture and good responsiveness to fertilizers, it would be feasible to increase agricultural production on land areas already developed and to expand crop areas, which has been envisioned in the decree of the Central Committee of the CPSU and the Council of Ministers of the USSR On Measures for the Further Development of Agriculture in the Nonchernozem Zone of the RSFSR of March 1974. Although the subzone of sod podzolic soils has enormous areas suitable for cultivation, only 13.3 percent is currently under agricultural use, significantly less than in the chernozem zone. The chief reasons are the ruggedness of the terrain, the widespread distribution of waterlogged and bog soils, which require treatment, and the presence of significant areas of unfertile sandy soils. The complex structure of the soil cover also impedes the development of a large part of this territory.

A fairly extensive area of arable land, about 3 percent of the country’s total, is located in the dry subtropics, the zone of southern sierozems and gray cinnamon soils. The sierozems and gray-cinnamon soils are rich in all nutrients except nitrogen, have fairly good physical properties, are generally found on plains, and are for the most part irrigated, which makes it possible to grow heat-loving crops, such as cotton, rice, and valuable fruits. The soils in these regions are subject to salinization and some have been salinized. Irrigation systems with drainage runoff networks have been constructed to control salinization, and flushing and proper irrigation schedules have been instituted.

During the years of Soviet power, the use of arable land has been improved and vast areas have been brought into agricultural use. The area under cultivation in Russia (within current boundaries) amounted to 118.2 million ha in 1913, whereas in the USSR it rose to 150.6 million in 1940, 209.1 million ha in 1965, and 217.7 million ha in 1975. The development of virgin and idle lands in the period 1954–60 increased the area of arable lands, including planted areas; these lands are primarily located in the steppe and forest-steppe zones with chernozem, chestnut, and gray forest soils, mostly in the eastern parts of the country (Siberia, Kazakhstan, the Urals, and the Volga Region), primarily for the production of grains. (See below:: Agriculture.)

Irrigation and drainage are of great importance for improving the productivity of various kinds of soils. The area of irrigated land, which totaled 4 million ha in 1913, rose to 8.1 million ha in 1940, 9.9 million ha in 1965, and 14.5 million ha in 1975. Most such lands are located in the semidesert and desert zones with sierozems, gray cinnamon soils, and other soils. The steppe, forest-steppe, and forest zones account for an insignificant share of irrigated farming (not more than 15 percent of all the country’s irrigated lands), but this share has been steadily increasing every year in connection with the construction of vast irrigation systems in the southern Ukraine, the Volga Region, the Northern Caucasus, and elsewhere. The total area of drained land in the USSR was 5.5 million ha in 1940, 10.6 million ha in 1965, and 13.7 million ha in 1975, compared to 3.2 million ha in 1913. Most of the drained lands are located in the subzone of sod podzolic soils: peat-bog, bog podzolic, and other soils. About one-half of the drained lands at kolkhozes, sovkhozes, and other state enterprises have enclosed drainage. A significant expansion of drainage and irrigation is planned for the future, as well as the introduction of measures to improve salinized, solonetz, and acid soils.

The control of water and wind erosion is an important problem in soil improvement. Approximately 30–35 million ha of arable land are subjected to varying degrees of destructive action by erosion. Recultivation—the restoration of the soil cover of unused mines, peat bogs, and the like—is becoming increasingly important. A great deal of attention is being devoted to the protection

of soil resources against contamination by pesticides and industrial wastes. The use of soil resources is regulated by the Basic Principles of Land Legislation of the USSR and the Union Republics (1968). Increasing the productivity of cultivated lands is the most important task of land use.

Bibliography

The flora of the USSR is extremely diverse and rich in the number of plant species, especially in the southern mountain regions. All of the USSR lies in the Holarctic floristic region (kingdom), the earth’s northernmost floristic region.

The fundamental regularities of plant distribution are associated with many factors, principally with the distribution of heat and moisture, and it is this that has determined the formation of the various geobotanical regions (or zones, in the broad sense of the word). Most of the regions extend latitudinally, but a few, such as the European and Far Eastern broad-leaved regions, located in the oceanic parts of the continent, extend longitudinally or diagonally. However, even in the latitudinal geobotanical regions there are certain differences in the composition and structure of the vegetation owing to changes in climate from west to east, as a result of which geobotanical subregions, provinces, and the like have been identified. In mountain systems, vertical vegetation zonation is observed. Moreover, a specific type (or closely allied types) of vegetation zonation has developed in each geobotanical region. Other ecological factors, the history of the plant cover, and the effects of man’s economic activities have also greatly influenced the composition and structure of the vegetation.

Continental glaciers (ice sheets) and extensive mountain glaciers, which advanced and retreated several times during the Anthropogene, have played an enormous role in the formation of the vegetation. As a result of the glacial advances, all the vegetation under the ice cover was completely destroyed, and extensive areas of permafrost were formed in the periglacial zone, where tundras developed, as well as unique cryoxerophytic periglacial steppes and, in some places, sparse forests of birch, larch, and pine. Older vegetation of various types, including forests, was preserved during the glacial periods mainly in the southern part of the USSR, while heat-loving plants were preserved in the shelter of the mountains of Middle Asia and Transcaucasia.

High-arctic polar-desert region. The high-arctic polar-desert region occupies the areas of the northernmost islands of the Arctic Ocean that are not covered with glaciers; in the continental USSR it occupies only the extreme north of the Taimyr Peninsula. Vegetation is either absent or poorly developed on aggregations of large rocks and gravel; 20 to 30 percent of the fine-earth substrate, which is broken by frost cracks, is covered with crustose lichens, algae, and liverworts. Flowering plants are found in fissures between the stony polygons and in some depressions, where snow accumulates, as well as mosses and fruticose lichens, which occupy 10 to 15 percent of the entire surface.

Arctic tundra region. The arctic tundra region occupies a more or less narrow band in the north of the continent, as well as a few southern islands of the Arctic Ocean. The vegetation here is characteristically treeless, mainly because of insufficient warmth, and is represented by a cover of ground mosses (Bryales, such as Hylocomium, Aulacomnium, Tomenthypnum, Rhacomitrium, and Rhytidium, as well as Polytrichum and Sphagnum) or lichens (mainly fruticose lichens, such as Cladonia, Cetraria, and Alectoria, which predominate mainly on light and stony soils). In the tundra a stratum of dwarf shrubs and perennial herbaceous plants is also developed. Bogs, mainly hummocky ones, occupy a large area.

The characteristics of the plant cover in the tundra zone change substantially from north to south. The northernmost strip of the arctic tundra (transitional to the high-arctic deserts) is characterized by herbaceous-dwarf-shrub-moss and dwarf-shrub-lichen covers. Dwarf shrubs include mountain avens (in the west Dryas octopetala, and in the east, Dryas punctata and others) and willows (Salix polaris, Salix nummularia, and Salix reptans). Herbaceous plants include arctic and arcto-alpine species. Next is a strip of northern, or typical (moss-lichen), tundras, which differ from the preceding strip by the presence of a number of hypoarctic species, such as Eriophorum vaginatum, which form hummocky tundras east of the Lena River. Crowberry (Empetrum hermaphroditum), cloudberry (Rubus chamaemorus), and other such plants grow in places. The strip of southern, or shrub, tundras is characterized by a marked shrub stratum, consisting of dwarf birches (Betula nana in Europe and Western Siberia and Betula exilis in Eastern Siberia) and willows (Salix lanata, Salix glauca, Salix pulchra), and by a herbaceous-dwarf-shrub stratum, composed of mountain cranberry (Vaccinium vitis-idaea), the crowberry, and other plants. Marsh tea (Ledum palustre) occurs occasionally. The southernmost strip—the forest tundra, or subtundra sparse forests—is characterized by sparse-forest communities combined with large dwarf-birch tundras in the level divide areas (placors); hypoarctic and taiga species predominate. In the European part the sparse forests of the tree stratum are dominated by the birch Betula tortuosa and Siberian spruce (Picea obovata); in Western Siberia, by Siberian larch (Larix sibirica); and in Eastern Siberia, by the dahurian larch (Larix gmelina).

Northern Pacific tall-herb small-leaved forest low-mountain tundraregion. This region, which is marked by a cold, humid climate, occupies Kamchatka and the northern and middle Kuril and Komandorskie islands. It is characterized by forests with sparse stands of the birch Betula ermanii, usually with a heavy tall-herb cover consisting of the hellebore Veratrum oxysepalum, the meadowsweet Filipendula camtschatica, the angelica Angelica ursina, the cow parsnip Heracleum dulce, and the thistle Cirsium camtschaticum. High-altitude shrubs, such as the dwarf stone pine (Pinus pumila) and the alder Alnus camtschatica, often grow down to sea level. Coniferous forests of Yeddo spruce (Picea jezoensis) and dahurian larch are found only in the valley of the Kamchatka River, which is surrounded by mountains on the west, east, and south.

Northern European-Siberian taiga (coniferous-forest) region. The northern European-Siberian taiga region, which extends from the Baltic Sea basin to the Sea of Okhotsk, occupies about one-half of the USSR. Forests dominated by mesophilic coniferous trees prevail, including both evergreen species—spruce, fir, and pine—and deciduous species—larch. Dwarf shrubs and herbs include the mountain cranberry (Vaccinium vitis-idaea), the bilberry (Vaccinium myrtillus), the bearberry (Arctostaphylos uva-ursi), the twinflower (Linnaea borealis), and various ferns, such as Dryopteris lanceolatocristata, Gymnocarpium dryopteris, and Phegopteris connectilis. The ground cover consists of Bryales, mainly Pleurozium schreberi, Hylocomium splendens, and Dicranum polysetum, on light soils in pine forests. In the northern taiga and in other coniferous forests it consists of various lichens of the genera Cladonia and Cetraria, and in marshy forests, of various species of Polytrichum and Sphagnum. Upland sphagnum bogs often form large massifs; extensive areas of the Western Siberian Lowland are covered with bogs.

In the northern part of the European USSR and in Western Siberia east of the Enisei River, the Enisei Ridge, and the Saian Mountains (where the forests are mountainous), dark-coniferous forests of spruce, fir, and nut pines predominate, including the Norway spruce (Picea abies), the Siberian spruce (Picea obovata), the Siberian fir (Abies sibirica), and the Siberian stone pine (Pinus sibirica). In some places, especially in the north, there is an admixture of Siberian larch; on light soils there are pine forests of Scotch pine (Pinus sylvestris). Birch forests grow on sites of felled trees and fires, and such forests now prevail in many regions. Larch forests are predominant east of the Enisei River: dahurian larch in the northern part of Central Siberia and in Eastern Siberia and Siberian larch (Larix sibirica) in the southern part of Central Siberia (intermixed with Scotch pine in the south). The vast expanses of Central and Eastern Siberia, dominated by larch forests, are underlain by permafrost. Small, individual communities of the Central Asian (Mongolian) type are occasionally found in the easternmost continental part of the taiga region in the far northeast—in the central part of the Lena River basin (in the vicinity of the city of Yakutsk) and along the upper reaches of the lana, Indigirka, and Kolyma rivers.

In the Far East, in the basin of the lower and partly the middle Amur River, as well as in the central and southern parts of Sakhalin and in the southernmost Kuril Islands, large areas are occupied by dark coniferous, mainly mountainous, forests of Yeddo spruce and the firs Abies nephrolepis and Abies sachalinensis, which in the south are intermixed with Far Eastern broad-leaved trees and shrubs. In the mountains of the taiga region, coniferous forests cover the lower and middle elevations of the mountains. Higher up is a belt of low-growing high-altitude shrubs, for example, dwarf species of birch, and, in Eastern Siberia, dwarf stone pine. In the Far East there are thickets of Betula ermanii above the belt of coniferous forests, while the high-altitude zone is occupied by mountain tundras (bald mountains).

The species composition and structure of the taiga forests change from north to south. The northern taiga is characterized by sparse stands of trees. The underbrush consists of low-growing shrubs similar to the ones growing in the tundras, for example, the dwarf birch and the birch Betula exilis. The herbaceous-dwarf-shrub stratum has taiga and a few arctic species, including mountain cranberry and bilberry. The ground cover of mosses and lichens is well developed.

In the central taiga, the tree stand is denser and is characterized by a medium or high site index. Shrubs are usually absent, and there are no arctic species in the herbaceous-dwarf shrub stratum. The moss cover of Bryales is well developed, while lichens occur only in the pine forests.

In the southern taiga the tree stand is also dense and is characterized by a middle or high site index. In addition to mountain cranberry and bilberry, the herbaceous-dwarf-shrub stratum also includes the European wood sorrel (Oxalis acetosella). The ground cover here is less well developed than in the central taiga. In the southern taiga forests of the European USSR and the Far East, there are several herbaceous species that are characteristic mainly of broad-leaved forests, while in Southern Siberia, in the pine and larch forests, there is a herbaceous cover of forest species, as well as occasional meadow-steppe species.

In the extreme south of the taiga region in the European USSR and in the Far East, there is a strip of mixed broad-leaved and coniferous forests, with broad-leaved trees in the tree and shrub strata and with plants characteristic of oak forests in the herbaceous-dwarf-shrub stratum. The moss and lichen ground cover is less marked than in the more northerly strips. In Western Siberia, south of the southern dark-coniferous taiga strip, there is a narrow band of aspen-birch forests, consisting of the European, or silver, birch (Betula pendula), the downy birch (Betula pubescens), and the aspen (Populus tremula).

Far Eastern broad-leaved forest region. The Far Eastern broad-leaved forest region is represented in the USSR only by its northernmost part, a narrow strip in the basin of the middle Amur; the greater part of it lies in adjacent foreign regions of Asia. The region, as well as the neighboring dark-coniferous forest region to the north, is under the influence of a monsoon climate. Its flora is extremely rich, especially in the diversity of tree and shrub species. Broad-leaved forests predominate on the plains and in the lower mountain elevations; in the USSR they consist mainly of the Mongolian oak (Quercus mongolica) and the hornbeam (Carpinus cordata), as well as of such lindens as Tilia amurensis, several species of maple, and other trees. Above the broad-leaved forest belt are mixed cedar and broad-leaved forests, in which the dominant conifers are the Korean pine (Pinus koraiensis) and the fir Abies holophylla. In the broad-leaved forests and especially in the mixed forests, woody lianas abound: the Chinese magnolia vine (Schizandra chinensis), the Amur grape (Vitis amurensis), and several species of Actinidia. Still higher is a zone of dark-coniferous forests (Yeddo spruce and fir), which give way at the mountain summits to low-growing forests of Betula ermanii. In the southern part of the Sikhote-Alin’ Mountains, near the timberline, there are thickets of the coniferous creeping shrub Microbiota decussata, growing on rock streams.

European broad-leaved forest region. The European broad-leaved forest region encompasses the Carpathian Region and the Carpathian Mountains and extends eastward in a narrow strip to the western slopes of the Southern Urals, encompassing the Poles’e. In the south it extends to the mountains of the Crimea, the Greater Caucasus, and the Rioni Lowland (Colchis Lowland) and partly encompasses the mountainous regions of the Lesser Caucasus. Most of the European broad-leaved forest region is in Western Europe; it extends into the USSR in two narrow wedges. In the northern strip there are few tree species, especially in the east. In the Carpathian Region and on the Podol’e Upland, the Central European durmast oak (Quercus petrea) still covers considerable areas, but the greater part is dominated by the English oak (Quercus robur). The European hornbeam (Carpinus betulus) grows as far as the left bank of the Dnieper River, while the European ash (Fraxinus excelsior) grows almost as far as the right bank of the Volga. The littleleaf linden (Tilia cordata), Scotch elm (Ulmus glabra), and various maples, mainly the Norway maple (Acer platanoides), also grow in the oak forests. The European hazel (Corylus avellana) and other trees are common in the underbrush. Oak forests occupy the Podol’e Upland and the foothills of the Carpathians. Higher up are forests of European beech (Fagus sylvatica), followed by a belt of coniferous forests of spruce and fir, including the Norway spruce and the common silver fir (Abies alba). Higher still is a zone of subalpine dwarf shrubs, mainly Swiss mountain pine (Pinus mugo), and thickets of scrub alder—Alnus viridis. The mountain summits are occupied by alpine meadows; the herbaceous communities are for the most part secondary, having arisen on the site of destroyed forests.

In the southern strip of the European broad-leaved region, which encompasses the Caucasus and the mountains of the Crimea, the species composition is richer. Here too there is a predominance of oak forests, consisting of Quercus iberica and, in some places, of Quercus pedunculifera; growing on the northern slopes of the Greater Caucasus and in the mountains of the Crimea are the English oak, the durmast oak, and Quercus pubescens; above this is a zone of oriental beech (Fagus orientalis).

The vegetation of western Transcaucasia, where precipitation is abundant, is unique. Here, in the low mountain elevations and on the submontane plains, there are mixed broad-leaved forests of Spanish chestnut (Castanea sativa), oriental beech, and various oaks, including Quercus iberica and Quercus hartwissiana; evergreens often occur in the underbrush, for example, Laurocerasus officinalis and Rhododendron ponticum. The next higher level consists of beech forests, in some places with an evergreen underbrush of similar composition. Still higher is a zone of dark-coniferous forests of fir and spruce, such as the Nordmann fir (Abies nordmanniana) and the oriental spruce (Picea orientalis), with an admixture of broad-leaved species, for example, beech; evergreen underbrush is sometimes encountered in the more westerly regions. Elfin woodland of beech or birch forms the upper boundary of the forest. In the subalpine zone are thickets of tall herbs and Caucasian rhododendron (Rhododendron caucasicum), with savin (Juniperus sabina) occurring in the drier regions. The alpine zone of the mountains of the Caucasus is occupied by low-herb meadows rich in species composition.

The mountains of the Crimea are dominated by oak forests of European species, such as the durmast oak and Quercus pubescens; in some places there are forests of oriental beech. On the southern slopes of the Crimean Mountains, as well as on the northwestern part of the southern slopes of the Greater Caucasus, there are sylvan Mediterranean and sub-Mediterranean species of pine—Pinus pallasiana—as well as the spiny Greek juniper (Juniperus excelsa). The pine Pinus pityusa occurs in the Caucasus.

Eurasian steppe region. The Eurasian steppe region extends latitudinally in the interior of the continent within the temperate zone from the lower reaches of the Danube to the interior of Tungpei in the People’s Republic of China; in the USSR it is represented mainly in the southern European part of the country, in Western Siberia, and in northern Kazakhstan. It is characterized by the prevalence of perennial caespitose xerophilic herbaceous plants, mainly caespitose grasses of the genera Stipa, Festuca, Koeleria, and, more rarely, Carex (Carex pediformis and Carex humilis) and Allium (chiefly in Mongolia). The composition and structure of the plant communities change from west to east. Thus, in the Black Sea and Kazakhstan steppes there is a predominance of large feather grasses, such as Stipa zalesskii, Stipa ucrainica, and Stipa lessingiana, while the capillary feather grasses, such as Stipa capillata and Stipa sareptana, are less important; Festuca valesiaca and allied species are ubiquitous. In the Central Asian type steppes, which in the USSR occur in Transbaikalia (the island steppes of the upper Enisei), such capillary feather grasses as Stipa krylovii and Stipa baicalensis predominate. Various fescues, primarily Festuca lenensis, are distributed in the more northerly, mainly meadow, steppes; Cleistogenes squarrosa is characteristic. Owing to a relatively warm and wet spring, various ephemeroids develop in the spring and early summer on the Black Sea and Kazakhstan steppes, such as the bulbous bluegrass (Poa bulbosa), various species of Gagea, tulips (Tulipa schrenkii and Tulipa patens), and Rindera tetraspis, as well as various ephemerals, such as several species of the genus Bromus, Ceratocephala testiculata, Erophila verna, and Alyssum desertorum. Owing to cold, dry springs, there are few ephemeroids and ephemerals in the Central Asian steppes, but in wetter years long-vegetating (from spring to autumn) annual and biennial plants are abundant, especially wormwoods, including Artemisia scoparia, Artemisia pectinata, and Artemisia palustris.

In the steppe region changes in the species composition are observed from north to south, as well as changes in populations of various life forms. The drought resistance of plant species increases, and the number of species of ephemeroids and ephemerals increases. As a result, the steppe region is divided into four major latitudinal strips. The meadow steppes have species characteristic of meadows, such as Agropyron (quack grass); the principal feather grass is Stipa pennata. The arid forb caespitose grass steppes are characterized by steppe forb, which resembles that of the meadow steppes; the principal feather grass is Stipa zalesskii, with Stipa ucrainica occurring occasionally in the west. In the arid caespitose grass steppes, the role of steppe forb decreases, and the principal species of feather grass is Stipa lessingiana. The desert, subshrub caespitose grass steppes are dominated by steppe caespitose grasses—Stipa sareptana. Stipa lessingiana also occurs in the north, but subshrubs are also important: wormwood, such as Artemisia lercheana and Artemisia gracilescens, and some saltwort species, for example. Anabasis salsa. Forests occur in the level divide areas in the meadow-steppe strip—oak forests in the European part and birch forests in the southern part of Western Siberia.

In the steppes of Transbaikalia, which resemble the Central Asian steppes in composition, structure, and phenological rhythms of development, there is a predominance of meadow steppes, in which, in addition to capillary feather grasses and Festuca lenensis, a large role is often played by Tanacetum (tansy) of the family Compositae. Also represented in Transbaikalia are forb, capillary feather-grass steppes and partially arid capillary feather-grass steppes with an abundance of Cleistogenes squarrosa.

Sahara-Gobi (Afro-Asiatic) desert region. The Sahara-Gobi desert region extends in the USSR from the Western Caspian Region (including the eastern part of Transcaucasia) to the borders of the People’s Republic of China. It is characterized by a predominance of subshrub, shrub, and treelike species, including saltworts, saxaul, Anabasis, and Ceratoides. In the USSR the northern part of the region is located in the temperate climatic zone, while the southern part is in the subtropical zone.

Three latitudinal strips may be distinguished within the desert region: the northern deserts, the typical deserts, and the southern deserts. In the northern, or steppelike, deserts, which border on the steppe region in the north, there is a predominance of sub-shrub wormwoods similar to those of the desert steppes (Artemisia lercheana, Artemisia gracilescens, Artemisia pauci-flora) or typically desert wormwoods (for example, Artemisia terrae-albae), as well as desert subshrub saltworts (Anabasis salsa, Salsola arbusculiformis) and steppe caespitose grasses, including fescue (Festuca valesiaca) and feather grass (Stipa sareptana, Stipa richteriana).

In the typical deserts, there is a predominance of subshrubs similar to those of the steppe deserts, but there are no steppe caespitose grasses (they appear only on light soils).

In the southern deserts, which are confined to the southern part of the Turan Lowland and the eastern part of Transcaucasia, ephemeroids and ephemerals are developed—Poa bulbosa and Carex pachystylis; Carex physodes grows on sand in thickets of saxaul and Calligonium. The most common desert subshrubs are Artemisia fragrans, Salsola dendroides, Salsola nodulosa, and Salsola ericoides in Transcaucasia and numerous wormwoods, such as Artemisia turanica, Artemisia kemrudica, and Artemisia badhysi, and various saltworts, including Salsola gemmascens and Salsola arbuscula, in the southern part of Middle Asia. On the sands of southern Kazakhstan and Middle Asia are thickets of saxaul (Haloxylon ammodendron, Haloxylon persicum) and many species of Calligonium.

The plant cover of the mountain systems within the desert zone (in the southern and eastern parts of Transcaucasia, in Kazakhstan, and in Middle Asia) is diverse. It is here that more than one-half of all the species of higher plants in the USSR are found. The common features of all the mountainous areas are poor forestation or the complete absence of forests (in many areas the forests have been destroyed by man) and the general xerophilic nature of the vegetation. In the lower elevations in the eastern and southern parts of Transcaucasia, mats of Andropogon (beardgrass) are common. In the middle and some lower mountain elevations, there are caespitose grass steppes, similar to the steppes of the European USSR. On the rocky slopes there are communities of mountain xerophytes—mats of tragacanths (thorny subshrub species of Astragalus) and thyme (xerophilic subshrubs, especially of the family Labiatae). In some places of this zone, there are xerophilic sparse forests (to a considerable degree already destroyed) of treelike junipers, such as Juniperus foetidissima, and Juniperus polycarpos, and pistacias, for example, Pistacia mutica. Oak forests have been preserved in some places. In the southeastern part of Transcaucasia, in Talysh, there are forests with a predominance of chestnut-leaf oak (Quercus castaneifolia), oriental beech, and, in some places, Persian parrotia (Parrotia persica).

In the Dzungarian Alatau and in the northern and central Tien-Shan, in the lower and middle elevations, the landscape is dominated by caespitose grass and meadow steppes, similar to the steppes of northern Kazakhstan; shrub thickets occur in places. In the upper part of the middle-altitude belt there are massifs of mountain forests of Schrenk’s spruce (Picea schrenkiana). In the lower part of the high-altitude belt are sparse thickets of Juniperus turkestanica and high-altitude steppes and meadows; the latter include communities of Cobresia of the family Cyperaceae, which are especially characteristic of the central Tien-Shan.

In the western Gissar-Alai, the southern Tien-Shan, the western Pamirs, and the Kopetdag and on the submontane plains and low foothills (adyry) there are ephemeroid communities of bulbous bluegrass and the sedge Carex pachystylis, together with other ephemeroids, numerous ephemerals, and, sometimes, subshrub wormwood of the subgenus Seriphidium. The higher foothills and the lower parts of the middle-altitude belt are occupied by communities of tall, ephemeroid herbs, such as Elytrigia trichophora and Hordeum bulbosum. Similar communities are sometimes called semisavannas. Sparse forests of Pistacia vera have been preserved in some places at low elevations. The middle-altitude mountain belt is characterized by a combination of semisavanna, middle-altitude meadows, shrub thickets of various species of dog roses, almonds, and other plants, and occasional sparse juniper forests (Juniperus semiglobosa, Juniperus seravschanica). There are also communities of tragacanths (thorny xerophilic dwarf shrubs of the genera Astragalus, Onobryhis, and Acantholimon), especially on rocky slopes, as well as thyme mats and communities of herbaceous thorny Cousinia. True forests (of walnut, maple, and wild species of apple) are found rarely and then only in areas with greater precipitation, mainly on the northern slopes. In the high-altitude belt there are high-mountain steppes, meadows, and tragacanth mats, and in the lower elevations, sparse thickets of the prostrate shrub Juniperus turkestanica.

As a result of man’s economic activities, areas formerly occupied by forests have declined sharply. The eastern Pamirs are part of the Central Asian desert subregion and are dominated by high-altitude deserts of Eurotia ceratoides (or Ceratoides latens), Artemisia rhodantha, and Ajania tibetica.

The natural plant cover of the USSR has been altered considerably by the economic activities of man. Enormous areas of the steppes and many formerly wooded areas have been replaced by field crops. The forests of the European part of the USSR are no longer dominated by coniferous trees but by small-leaved species, such as birch and aspen. As a result of intensive cattle grazing, the vegetation of pasturelands has also been considerably altered.

The natural vegetation of the USSR is of great importance to the national economy (see below: Plant resources). The natural plant cover, formed over the course of countless centuries, is vital to the stability of the biosphere. Natural vegetation, which consists mainly of perennial plants, creates a gaseous composition of the atmosphere suitable for all living organisms, stabilizes the topography, and plays a major role in water conservation and in soil and wind protection. The plant cover is an important healthful factor and helps satisfy man’s cultural and aesthetic requirements. Natural vegetation should be regarded with care. In using it for the national economy, it is important to take into account the entire diversity of the complex relationships existing in living nature as a result of a long evolutionary process (see below: Conservation).

Bibliography

Plant resources—the flora and the varied plains and mountain (zonal and intrazonal) vegetation—constitute part of the natural wealth of the USSR. The role of food and forage plants, which serve as a raw material in industry and the production of medicinal preparations, is very important.

Twenty thousand species of higher plants grow in the USSR, including Angiospermae (flowering plants), Equisotophyta (horsetails), Lycopodium (club mosses), and Polypodiophyta (ferns), as well as 15,000 to 20,000 species of mosses, which are widely distributed throughout the country (in forests, bogs, and tundras). Areas that are richest in plant species are Middle Asia (7,000 species), the Caucasus (6,000), the Crimea (2,000), and the Far East (1,900 to 2,000). The flora of the arctic islands of Siberia is the poorest, numbering no more than 100 to 150 species. The USSR has no less than 50,000 species of lower plants, including 10,000 species of algae, 5,000 species of lichens, and about 35,000 species of fungi. Thus, the total flora of the USSR comprises 90,000 to 100,000 species, excluding bacteria and actinomycetes.

Forests. Of the greatest economic significance are the forests, which are the source of hard and soft woods (for lumber and wood products) and raw material for the pulp and paper, hydrolysis, wood-chemical, and other branches of industry. Forests also serve as the habitat of many commercially useful animals. The area covered by forests (according to data compiled Jan. 1, 1978) is 791.6 million hectares (ha), which amounts to 35.6 percent of the country’s total area. The total lumber reserves are 84 billion cu m. Coniferous forests yield the largest quantity of lumber (80 percent). The most widespread tree species are larch (265 million ha), pine (115 million ha), Siberian stone pine (40 million ha), and spruce (77 million ha). Most of the forests occur in Siberia, the Far East, and the northern part of the European USSR; the forest wealth is unevenly distributed among the Soviet republics (see Table 12). Moreover, forests are the source of various secondary products—succulent fruits (wild apples, cherry plums, cornelian cherries, and pears), berries (blueberries, mountain cranberries, raspberries), and nuts (filberts, walnuts, and pine nuts), which amount to at least 11 million tons a year. Annual reserves of edible fungi do not exceed 4 to 5 million tons, which constitutes only a small percentage of the potential mushroom production.

Hayfields and pastures. Hayfields and pastures, which yield substantial quantities of phytomass for cattle fodder, are economically important. Approximately 10,000 species of plants, which produce 77 to 78 percent of raw fodder, grow in hayfields and pastures, mainly cereal grasses, legumes, and forbs, which grow on meadows and steppes; wormwoods and saltworts grow in the semideserts. In 1975 the natural pastures of the USSR (in all categories of farms) occupied 329 million ha. In addition, there were 334 million ha of reindeer pasture.

Pastures account for a considerable part of the total agricultural lands in Turkmenia (about 97 percent), Uzbekistan (84 percent), Kirghizia (84 percent), Kazakhstan (81 percent), Tadzhikistan (about 79 percent), and Latvia (24.6 percent). In the Ukraine, Lithuania, Byelorussia, and Moldavia and in the central regions of the RSFSR, they account for 10 to 20 percent of all agricultural lands. Irrigated hay-producing meadows have the highest yields of phytomass. On farms in Middle Asia and the Caucasus, winter pastures (wormwood deserts) and summer pastures (alpine and subalpine meadows), which serve as the basis for transhumant stock raising, are of great importance.

Medicinal and industrial plants. About 400 species of medicinal plants grow in the USSR, about 150 wild species are gathered, from which about 20,000 tons of raw material are obtained annually containing various compounds used in medicine. Up to 150,000 tons of tanbark is gathered yearly from spruce and willow and partly from oak for the production of tanning extracts. Good results have been obtained from plantings of root tanning plants (knotweed) and herbaceous tanning agents (cranesbill), which contain 12 to 30 percent tannins. Some plants produce resins, swelling and soluble gums, dye pigments, essential oils, and many other substances used in various branches of industry and technology. However, as a result of the intensive development of chemistry, the role of plants in these industries is gradually decreasing. Thus, rubber-bearing plants, gutta-percha plants, and some others have lost their importance.

Aquatic plants. The seas of the USSR are rich in marine plants, with macrophyte reserves amounting to 22 million tons (actual production, about 70 million tons). The northern seas of the USSR total 277 species of plant organisms. Vegetation is sparse in the arctic-desert zone, consisting of mosses and lichens. In the tidal zones of the White and Barents seas, as well as in the sublittoral zones, macrophytes are well developed; the total reserves of vegetation in these seas amount to more than 2 million tons. In the southern seas of the USSR, vegetation is represented by 291 species of algae and ten species of herbaceous plants; the Black Sea, with 278 species, is the richest. Confervoid algae and herbaceous plants are developed in the Sea of Azov and the Caspian Sea; total reserves amount to more than 10 million tons. The seas of the Far East contain as many as 550 species of algae and 15 species of herbaceous plants.

Some species of algae are used to obtain agar, iodine, and food products (sea kale); they are also used as fodder for cattle and as fertilizers. Research is being conducted on the use of algae, such as Chlorella and Scenedesmus, in the life-support systems of spacecraft.

Cultivated plants. Cultivated plants, which supply the principal food products for the population and the industrial raw materials for the food industry and light industry, constitute a considerable part of the plant resources of the USSR. Numerous plants of the natural flora possess many economically valuable features and consequently are important for improving the cultivated flora. (For measures to protect natural plant resources, see below: Conservation.)

Bibliography

The fauna of the USSR is highly varied, both because of the fairly great diversity of conditions prevailing on land and on the seas and because of the great extent of the land mass from north to south and west to east. On the other hand, owing to the northern location of most of the USSR’s land mass and the bordering seas, the fauna of the USSR comprises fewer species than the fauna of tropical and equatorial countries.

The following is a list of the number of species in the USSR, including those inhabiting bodies of freshwater and seas. There are more than 300 species of mammals, about 760 species of birds, about 140 species of reptiles, and more than 30 species of amphibians. The number of fish species is about 1,400, including about 528 freshwater and migratory species. There are nine species of cyclostomes, one acraniate species, about 130 species of tunicates, about 410 species of echinoderms, and about 450 species of bryozoans, including 27 freshwater species, as well as 2,000 species of mollusks, including about 600 terrestrial species, about 470 freshwater species, and 1,100 marine species.

Insects are numerous, amounting to 80,000 to 100,000 species, of which there are about 20,000 species of dipterans (according to some sources, 10,000), about 10,000 species of hymenopterans, about 8,500 species of lepidopters, about 600 species of trichopterans, about 25,000 species of coleopterans, about 2,000 species of hemipterons, more than 800 species of aphids, about 250 species of scale insects, more than 700 species of orthopterons, and about 160 species of odonates. Of the total 5,000 species of Chelicerata, there are 2,500 species of acarians, about 2,000 species of arachnids, about 350 species of Pantopoda, about 70 species of tardigrades, about 70 species of Opiliones (or Phalangida), about 70 species of solpugids, and 12 species of scorpionids. Crustaceans number 3,000 species, annelid worms about 1,100 species, including about 750 species of polychaetes and about 300 species of oligochaetes, of which earthworm species number 100 and leech species number 60. In addition, there are more than 100 species of nemertines, about 1,800 species of nemathelminths (including about 115 species of acanthocephalans, about 700 species of rotifers, and about 1,000 species of nematodes), about 2,000 species of platyhelminths, about 500 species of coelenterates, more than 300 species of poriferans, numerous protozoans, and somewhat more than 100 species belonging to various different groups, including priapulids, sipunculids, echiuroids, and pogonophores.

The total number of known species occurring in the USSR ranges from 125,000 to 130,000 (or more according to some sources). Thus, if the total number of animal species now living is 1.3 million (about 1.5 million according to some zoologists), the USSR, which occupies about 15 percent of the world’s land area, or, taking the seas into account, about 8 percent of the earth’s surface, accounts for about 8 percent of the world’s fauna.

An important general feature of the distribution of the fauna in the USSR, as in the entire northern hemisphere, is that the number of total species, like the number of species in the individual groups, increases from north to south. Moreover, some southern Asian and African groups occur in the south. Another feature is zonation—the distribution of animals is distinctly related to natural zones on land and in the seas. The zonation is partly disrupted by the presence of some widely distributed species in several zones or throughout the entire country (or the seas), on the one hand, and by some aspects of the development of the fauna of the Soviet Union or its individual areas, on the other. However, the fauna of each of the main zones is an integral independent complex, intermingling with the neighboring fauna chiefly in the transitional zones, such as the forest tundra, forest steppe, and semidesert.

Terrestrial fauna. The USSR lies within the Palaearctic division of the Holarctic zoogeographic region. The zone of the northern islands and tundras forms part of the Arctic subregion, while the entire forest zone from the Pacific to the western borders of the USSR belongs to the Circumboreal subregion, the plains (deserts and semideserts) of Middle Asia and southern Kazakhstan, the Caspian Lowland, the Caucasus, Transcaucasia, and the southern part of the Crimea belong to the Mediterranean subregion, the mountains of Middle Asia and part of the mountains of Southern Siberia belong to the Central Asian subregion, and the Amur and Ussuri regions belong to the Sino-Himalayan subregion. Many zoogeographers assign the plains of Middle Asia and southern Kazakhstan to the Central Asian subregion.

Although the origin of the present-day fauna of the USSR can be traced to the Neogene, the main features of its distribution and composition developed during the Pleistocene, chiefly because of the glacial epochs and the changes in postglacial climatic conditions. The formation and historical fate of the fauna of the individual zones and zoogeographic regions proceeded in largely independent directions. An important factor affecting the distribution and, in part, the composition of the modern fauna is the direct and, especially, indirect (through changes in landscape) influences of man. It began in the distant past, in the Neolithic and even Paleolithic periods, and intensified in the last few centuries, particularly in the second half of the 20th century. There has been a marked tendency for the areas of distribution to decrease gradually in size and for the populations of species hunted by man to decline, as well as the populations of species that are incapable of existing in areas completely developed by man. On the other hand, those animals that were favored by economic changes in the landscape succeeded in settling more widely (synanthropic species). Some acclimatized species, for example, the muskrat and American mink, whose ranges widened considerably, have become an established part of the fauna.

COASTAL AND ISLAND FAUNA. Coastal and island fauna consists mainly of marine species of birds and mammals, whose distribution depends largely on prevailing marine conditions (food supply and ice). Such species are only partly linked to land (a narrow

Figure 1. Fauna of the oceanic coasts and islands: (1) black-legged kittiwake (Rissa tridactyla), (2) ivory gull (Pagophila eburnea), (3) fulmar (Fulmarus glacialis), (4) parasitic jaeger (Stercorarius parasiticas), (5) resplendent shag (Phalocroconax pelagicus), (6) least auk (Aethia cristatella), (7) thick-billed murre (Uria lomvia), (8) black guillemot (Cepphus grylle), (9) ancient murrelet (Synthliboramphus antiquus), (10) tufted puffin (Lunda cirrhata), (11) common puffin (Fratercula crctica), (12) dovekie (Alle alle), (13) Steller’s eider (Polysticta stelleri), (14) male common eider (Somateria mollissima), (14a) female common eider, (15) spoon-billed sandpiper (Eurynorhynchus pygmeus), (16) Steller’s sea lion (Eumetopias jubatus), (17) sea otter (Enhydra lutris), (18) walrus (Odobenus rosmarus), (19) northern fur seal (Callorhinus ursinus), (20) polar bear (Thalarctos maritimus), (21) harp seal (Phoca groenlandica), (22) ribbon seal (Phoca fasciata), (23) harbor seal (Phoca vitulina)

coastal strip), chiefly during the reproductive period. Characteristic of the fauna are various pinnipeds, including the walrus (Odobenus rosmarus), the bearded seal (Erignathus barbatus), the ringed seal (Pusa hispida), and the harbor seal (Phoca vitulina), as well as the polar bear (Thalarctos maritimus), and a number of birds, including guillemots (in the USSR found almost exclusively in this region), gulls, and eiders. The guillemots and gulls form huge nesting colonies, called rookeries, on the rocks. Extremely valuable fur-bearing species inhabit the Pacific seas, including the sea otter (Enhydra lutris; Komandorskie and Kuril islands) and the northern fur seal (Collorhinus ursinus; rookeries on Tiulenii, Komandorskie, and Kuril islands).

TUNDRA FAUNA. The tundra fauna comprises a small number of species. Among the characteristic mammals are various lemmings, such as the Norway lemming (Lemmus lemmus), the Ob’ lemming (Lemmus obensis), and the arctic lemming (Dicrostonyx torquatus), as well as the arctic fox (Alopex lagopus), the reindeer (Rangifer tarandus), and, in the eastern part of the country, the black-capped marmot (Marmota camtschatica). Among the species here that commonly inhabit other zones are a number of voles (Microtus), the blue hare (Lepus timidus), the ermine (Mustela erminea), the glutton (Guio guio), and the wolf (Canis lupus). Typical birds include the rock ptarmigan (Lagopus mutus), the willow ptarmigan (Lagopus lagopus), the snow bunting (Plectrophenax nivalis), the horned lark (Eremophila alpestris), the Lapland longspur (Calcarius lapponicus), the rough-legged hawk (Buteo lagopus), and the snowy owl (Nyctea scandiaca), as well as species associated with freshwater lakes and rivers, such as geese, ducks, and sandpipers. All the birds, except the ptarmigans and some snowy owls, migrate for the winter.

The number of invertebrate species is small; for example, there are only several hundred species of butterflies and moths. Sawflies and bumblebees are predominant among the hymenopterans. The coleopterans include many species of the families Staphylinidae (rove beetles), Carabidae (ground beetles), and Dytiscidae (predacious diving beetles). There are large numbers of bloodsucking dipterans, including those from the families Culicidae (mosquitoes), Simuliidae (blackflies), Ceratopogonidae (biting midges), and Tabanidae (horseflies).

FOREST-TUNDRA FAUNA. The forest-tundra fauna has no endemic species and consists of a mixture of tundra and taiga species that penetrated from the north and south.

TAIGA FAUNA. The fauna of the taiga is found in the northern part of the Far East, in Siberia, and in the northern part of the European USSR. It is most varied in Eastern Siberia and becomes less varied toward the west.

Characteristic mammals include several species of long-tailed shrews (Sorex), the northern red-backed vole (Clethrionomys rutilus), the gray red-backed vole (Clethrionomys rufocanus), the wood lemming (Myopus schisticolor), the Asiatic chipmunk (Eutamius sibiricus), the red squirrel (Sciurus vulpes), the Old World flying squirrel (Pteromys volans), the sable (Martes zibellina), the elk (Alces alces), and the musk deer (Moschus moschiferus), which lives in the Altai and east of the Enisei River. Marals (Cervus elaphus sibiricus and Cervus elaphus songaricus), the Manchurian red deer (Cervus elaphus xanthopygus), the Siberian roe deer (Capreolus capreolus pygargus), and the Siberian weasel (Mustela sibirica) inhabit the southern parts of the taiga zone. There are also mammals from other zones, for example, the blue hare, the brown bear (Ursus arctos), and the lynx (Felis lynx).

The most characteristic birds of the taiga are several species of warblers (Phylloscopus), a number of birds of the family Paridae, crossbills (Loxia), the brambling (Fringilla montifringilla), the Bohemian waxwing (Bombycilla garrulus), the pine grosbeak (Pinicola enucleator), the nutcracker (Nucifraga caryocatactes), the Siberian jay (Perisoreus infaustus), the three-toed wood-pecker

Figure 2. Fauna of the plains and mountainous tundras: (1) snow bunting (Plectrophenax nivalis), (2) Lapland longspur (Calcarius laponicus), (3) horned lark (Eremophila alpestris), (4) Siberian white crane (Grus leucogeranus), (5) arctic loon (Gavia arctica), (6) Bewick’s swan (Cygnus bewicki), (7) Ross’s gull (Rhodostethia rosea), (8) long-tailed jaeger (Stercorarius longicaudus), (9) white-fronted goose (Anser albifrons), (10) lesser white-fronted goose (Anser erythropus), (11) black brant (Branta bernicla), (12) red-breasted goose (Branta ruficollis), (13) king eider (Somateria spectabilis), (14) bluethroat (Luscinia svecica), (15) wolf (Canis lupus), (16) snowy owl (Nyctea scandiaca), (17) bighorn (Ovis canadensis), (18) the black-capped marmot Marmota camtschatica, (19) Middendorf’s vole (Microtus middendorti), (20) Norway lemming (Lemmus lemmus), (21) Ob’ lemming (Lemmus obensis), (22) arctic lemming (Dicrostonyx torquatus), (23) reindeer (Rangifer tarandus), (24) ermine (Mustela erminea), (25) arctic fox (Alopex lagopus), (26) rough-legged hawk (Buteo lagopus), (27) willow ptarmigan (Lagopus lagopus), (28) rock ptarmigan (Lagopus mutus), (29) Eurasian golden plover (Pluvialis apricaria), (30) bar-tailed godwit (Limosa lapponica)

pecker (Picoides tridactylus), the black woodpecker (Dryocopius martius), the hazel hen (Tetrastes bonasia), the capercaillie (Tetrao urogallus), Tengmalm’s owl (Aegolius funereas), the pygmy owl (Glaucidium passerinum), the great (or Lapp) owl (Strix nebulosa), the Ural owl (Slrix uralensis), and the hawk owl (Surnia ulula).

There are few reptiles and amphibians. The insect fauna is characterized by taiga and general forest species. Dipterans are

Figure 3. Taiga fauna: (1) pine grosbeak (Pinicola enucleator), (2) red crossbill (Loxia curvirostra), (3) Siberian jay (Perisoreus infaustus), (4) three-toed woodpecker (Picoides tridactylus), (5) black woodpecker (Dryocopius martius), (6) common goldeneye (Bucephala clangula), (7) Bohemian waxwing (Bombycilla garrulus), (8) redpoll (Acanthis flammea), (9) nutcracker (Nucitraga caryocatactes), (10) bullfinch (Pyrrhula pyrrhula), (11) capercaillie (Tetrao urogallus), (12) Siberian spruce grouse (Falcipennis falcipennis), (13) hazel hen (Tetrastes bonasia), (14) pygmy owl (Glaucidium passerinum), (15) Ural owl (Strix uralensis), (16) musk deer (Moschus moschiterus), (17) glutton (Guio guio), (18) European shrew (Sorex araneus), (19) sable (Martes zibellina), (20) wood lemming (Myopus schisticolor), (21) northern pika (Ochotona hyperborea), (22) the red-backed vole Microtus pullus, (23) gray red-backed vole (Clethrionomys rufocanus), (24) northern red-backed vole (Clethrionomys rutilus), (25) Old World flying squirrel (Pteromys volans), (26) Asiatic chipmunk (Eutamias sibiricus), (27) elk (Alces alces), (28) lynx (Felis lynx), (29) brown bear (Ursus arctos), (30) big brown bat (Eptesicus nilssoni), (31) Siberian weasel (Mustela sibirica), (32) European common lizard (Lacerta vivipara), (33) common viper (Vipera berus), (34) the tick Ixodes taigensis, (35) spruce longhorn (Tetropicum castaneum), (36) Siberian pine moth (Dendrolimus sibiricus), (36a) caterpillar of Siberian pine moth

numerous, primarily Tipulidae (crane flies) and Mycetophilidae (mushroom beetles). There are numerous bloodsucking insects, which are a great annoyance to animals and man. Lepidopters abound, especially Tortricidae (leaf-roller moths), Notodontidae

Figure 4. Fauna of the European and Far Eastern broad-leaved forests: (1) hawfinch (Coccothraustes coccothraustes), (2) thrush nightingale (Luscinia luscinia), (3) golden oriole (Oriolus oriolus), (4) blue tit (Parus caeruleus), (5) tawny owl (Strix aluco), (6) the long-horned beetle Cerambyx cerdo, (7) stag beetle (Lucanus cervus), (8) green lizard (Lacerta viridis), (9) smooth snake (Coronelia austriaca), (10) green woodpecker (Picus viridis), (11) bank vole (Clethrionomys glareolus), (12) common mole (Talpa europaea), (13) birch mouse (Sicista betulina), (14) European wildcat (Felis silvestris), (15) common tree frog (Hyla arborea), (16) fire-bellied toad (Bombina bombina), (17) the frog Rana temporaria, (18) European fire salamander (Salamandra salamandra), (19) hazel mouse (Muscardinus avellanarius), (20) garden dormouse (Eliomys quercinus), (21) tree dormouse (Dryomis nitedula), (22) European red deer (Cervus elaphus), (23) European mink (Mustela lutreola), (24) European, or pine, marten (Martes martes), (25) wild boar (Sus scrota), (26) roe deer (Capreolus capreolus), (27) Asiatic black bear (Ursus thibetanus), (28) aurochs (Bison bonasus), (29) raccoon dog (Nyctereutes procyonides), (30) goral (Nemorhaedus goral), (31) Japanese deer (Cervus nippon), (32) broad-billed roller (Eurystomus orientalis), (33) yellow-throated marten (Martes tlavigula), (34) Ussuri tiger, (35) azure-winged magpie (Cyanopica cyana), (36) mandarin duck (Aix galericulata), (37) Gould’s merganser (Mergus squamatus), (38) Bengal cat (Felis euptilura), (39) the long-horned beetle Cerambyx relictus, (40) the swallowtail Papilio machaon, (41) the soft-shelled turtle Amyda sinensis, (42) large Japanese mole (Mogera robusta), (43) the rat snake Elaphe schrenki, (44) Manchurian hare (Caprolagus brachyurus), (45) leopard (Panthera pardus), (46) ring-necked pheasant (Phasianus colchicus)

(prominent moths), Geometridae (inchworms), and Bombycidae (silkworm moths). Also abundant are hymenopterans (especially sawflies), aphids, and beetles, which are often associated with specific trees, for example, bark beetles. Spiders are more numerous here than in other zones.

BROAD-LEAVED FOREST FAUNA. The broad-leaved forest fauna occupies a triangular-shaped area in the European part of the country between the Gulf of Finland, the southern Urals, and Moldavia. The most typical mammals include the bank vole (Clethrionomys glareolus), the yellow-necked mouse (Apodemus flavicollis), and various microtines, such as the common dormouse (Glis glis), the tree dormouse (Dryomis nitedula), the garden dormouse (Eliomys quercinus), and the hazel mouse (Muscardinus avellanarius). Ungulates, including the roe deer (Capreolus capreolus), the European red deer (Cervus elaphus), and the aurochs (Bison bonasus), have survived in some wooded areas, as well as a number of other mammals, such as the European mink (Mustela lutreola), the European wildcat (Felis sylvestris), and the pine marten (Martes martes).

Among the characteristic birds are several species of warblers of the genera Phylloscopus and Sylvia, the chaffinch (Fringilla coelebs), the hawfinch (Coccothraustes coccothraustes), the nightingale (Luscinia megarhynchos), the oriole (Oriolus oriolus), the blue tit (Parus caeruleus), the green woodpecker (Picus viridis), the middle-spotted woodpecker (Picoides medius), and the tawny owl (Strix aluco).

Reptiles include the slow-worm (Anguis fragilis), the smooth snake (Coronelia austriaca), and Aesculapius’ snake (Elaphe longissima). Among the amphibians are the common European pond tortoise (Emys orbicularis), the tree frog (Hyla arborea), the edible frog (Rana esculenta), the common frog (Rana temporaria). Rana terrestris, the green toad (Bufo viridis), the fire-bellied toad (Bombina bombina), and the yellow-bellied toad (Bombina variegata), the last occurring in the Carpathian Region. Other amphibians include the great crested newt (Triturus cristatus), in the west, and the European fire salamander (Salamandra salamandra), in the Carpathians.

The insect fauna of the broad-leaved forest region is, in general, more varied than that of the taiga, but there are many common species, as well as several taiga species and a number of species that penetrated from the south.

FAR EAST (AMUR-USSURI) BROAD-LEAVED FOREST FAUNA. The fauna of the Far East (Amur-Ussuri) broad-leaved forests, found in the Ussuri River basin and the middle and lower Amur, is particularly abundant and varied and is characterized by a mixture of various northern and southern species. Among the latter, characteristic mammals include the large Japanese mole (Mogera robusta), the Manchurian hare (Caprolagus brachyurus), the Japanese deer (Cervus nippon), the goral (Nemorhaedus goral), the Asiatic black bear (Ursus thibetanus), the yellow-throated marten (Martes flavigula), the raccoon dog (Nyctereutes procyonides), the tiger, the snow leopard (Uncia uncia), and the Bengal cat (Felis euptilura).

Birds include several species of flycatchers, warblers of the genus Phylloscopus, buntings of the genus Emberiza, the Chinese oriole (Oriolus chinensis), the ashy minivet (Pericrocotus roseus), the Chinese white-eye (Zosterops erythropleurus), the azure-winged magpie (Cyanopica cyana), the broad-billed roller (Eury-stomus orientalis), the true pheasant (Phasianus colchicus), the mandarin duck (Aix galericulata), and Gould’s merganser (Mergus squamatus).

Reptiles include the spiny soft-shelled turtle (Trionyx sinensis), the long-tailed lizard (Tachydromus amurensis), the aquatic snakes Natrix tigrina and Natrix vibakari, and the rat snake Elaphe schrenki. Among the amphibians are the frog Hyla japonica and the triton Onychodactylus fischeri.

The insect fauna of the Far East broad-leaved forest is much more varied than in other parts of the USSR. Typical lepidopters

Figure 5. Steppe fauna: (1) European hare (Lepus europoeus), (2) steppe pika (Ochotona pusilla), (3) great bustard (Otis tarda), (4) collared pratincole (Glareola pratincola), (5) sociable plover (Chettusia gregaria), (6) white-winged lark (Melanocorypha leucoptera), (7) calandra lark (Melanocorypha calandra), (8) black lark (Melanocorypha yeltoniensis), (9) bobac (Marmota bobac), (10) spotted suslik (Citellus suslicus), (11) black-bellied hamster (Cricetus cricetus), (12) Eversmann’s hamster (Cricetus eversmanni), (13) whitetoothed shrew (Crocidura), (14) zokor (Myospalax myospalax), (15) major five-toed jerboa (Allactaga jaculus), (16) Russian mole rat (Spalax microphthalmus), (17) little bustard (Tetrax tetrax), (18) steppe, or tawny, eagle (Aquila nipalensis), (19) saiga (Saiga tatarica), (20) demoiselle crane (Anthropoides virgo), (21) steppe lemming (Lagurus lagurus), (22) steppe viper (Vipera ursini), (23) European sand lizard (Lacerta agilis), (24) lesser kestrel (Falco naumanni), (25) dahurian suslik (Citellus dauricus), (26) cape hare (Lepus capensio), (27) migratory locust (Locusta migratoria), (28) European whip snake (Coluber jugularis), (29) Mongolian gazelle (Gazella gutturosa), (30) manul (Felis manul), (31) Putorius eversmanni, (32) corsac (Vulpes corsac)

include Sericinus, Luehdorfia, many species of the families Notodontidae, Epicopidae, and others (found only here in the USSR), as well as the swallowtail Papilio bianor. The most common dipteran is the mosquito Megarhinus. Among the hemipterons are members of the tropical genera Plautia and Lelia. The largest insect in the USSR, Cerambyx relictus, is noteworthy. There are quite a few Tertiary relicts, for example, pedipalpids, which are characteristic of southern Asia.

The fauna of the southern part of Sakhalin is characterized by a mixture of northern and southern species, as is the fauna on the southern islands of the Kuril chain, which are also inhabited by several animal species that are native to Japan and not found elsewhere in the USSR, such as the Japanese grass vole (Microtus montebelli), the skink Eumeces latiscutatus, and three species of rat snakes (Elaphe).

FOREST-STEPPE FAUNA. The forest-steppe fauna contains very few species unique to the region and is characterized by a mixture of steppe and forest species.

STEPPE FAUNA. The steppe fauna contains comparatively few vertebrate species native to the steppes, but it is augmented by animals that penetrated from adjacent zones. This is particularly so in wooded areas (floodplain forests) or sandy areas (in the south). The Asiatic steppes of the USSR have the largest number of true steppe species, the number of which decreases westward. The European steppes have been virtually completely plowed up over the course of the last few centuries, and the composition of their fauna has been greatly altered. Some steppe species, such as the European hare (Lepus europoeus), the Hungarian partridge (Perdixperdix), the quail (Coturnix coturnix), and the pallid harrier (Cirus macrourus) are increasingly penetrating southward in the wake of extensive logging and cultivation deep in the broad-leaved forests and in the taiga.

Characteristic mammals of the European and Kazakh steppes include the bobac (Marmota bobac), various susliks, the blackbellied hamster (Cricetus cricetus), various cricetines, such as the migratory hamster (Cricetulus migratorius), several species of jerboas, the steppe lemming (Lagurus lagurus), mole rats, the steppe pika (Ochotonapusilla), the European hare, and the saiga (Saiga tatarica). Birds include the calandra lark (Melanocorypha calandra), the short-toed lark (Calandrella cinerea), the white-winged lark (Melanocorypha leucoptera), the black lark (Melanocorypha yeltoniensis), the bustard (Otis tarde), the little bustard (Tetrax tetrax), the lesser kestrel (Falco naumanni), the steppe (or tawny) eagle (Aquila nipalensi), the imperial eagle (Aquila heliaca), the demoiselle crane (Anthropoides virgo), the black-winged pratincole (Glareola nordmanni), and the sociable plover (Chettusia gregaria).

Reptiles, which are more numerous here than in the northern zones, include the steppe viper (Vipera ursini), the European whip snake (Coluber jugularis), the European sand lizard (Lacerta agilis), and a number of other species. Amphibians are few owing to the arid conditions. Locusts exist in great abundance, and many are major crop pests, such as the Asiatic, or migratory, locust (Locusta migratoria), which until recently had inflicted great damage. The hymenopterans are represented by a number of ant, wasp, sawfly, and other species. Among the coleopterans, the most common are the Curculionidae (snout beetles), the Carabidae (ground beetles), the Scarabeidae, and especially the Tenebrionidae (darkling beetles). There are many hemipteron and dipteran species.

The fauna of some areas of the Transbaikal steppes, which are more arid than the European and Kazakh steppes and which are inhabited by Mongolian fauna, differs significantly from the European and Kazakh steppes. The mammals that live here include the tarbagan (Marmota sibirica), the dahurian suslik (Citellus dauricus), the Mongolian vole (Microtus mongolica), Brandt’s vole (Microtus brandti), the dahurian pika (Ochotona daurica), and the cape hare (Lepus capensio); the Mongolian gazelle

Figure 6. Desert fauna: (1) great gerbil (Rhombomys opimus), (2) sand cat Felis margarita, (3) tiger weasel (Vormela peregusna), (4) saw-scaled viper (Echis carinatus), (5) caracal (Felis caracal), (6) porcupine (Hystrix cristata), (7) long-eared desert hedgehog (Hemiechinus auritus), (8) long-clawed ground squirrel (Spermophilopsis leptodactylus), (9) Selevin’s mouse (Selevinra betpakdalensis), (10) comb-toed jerboa (Parad i pus ctenodactylus), (11) cheetah (Acinonyx jubatus), (12) Pander’s ground jay (Podoces panden), (13) Pallas’s sandgrouse (Syrrhaptes paradoxus), (14) desert sparrow (Passer simplex), (15) desert warbler (Sylvia nana), (16) Houbara bustard (Chlamydotis undulata), (17) Asiatic wild ass (Equus hemionus), (18) brown-necked raven (Corvus ruficollis), (19) cobra (Naja naja), (20) the sand snake Eryx miliaris, (21) piebald shrew (Diplomesodon pulchellum), (22) the lizard Agama sanguinolenta, (23) the lizard Phrynocephalus, (24) whip scorpion, (25) variegated scorpion, (26) goitered gazelle (Gazella subgutturosa), (27) desert, or yellow, monitor (Varanus griseus), (28) Taphrometroron lineolatus

(Gazella gutturosa) may have penetrated from Mongolia. The Mongolian lark (Melanocorypha mongolica] is characteristic of the birds and the desert lacertid Eremias argus of the reptiles.

SEMIDESERT FAUNA. The semidescrt fauna, although noted for a few endemic species, is characterized primarily by a mixture of steppe and desert species.

DESERT FAUNA. The desert fauna is found on the plains of Middle Asia, including part of southern Kazakhstan, and in part of the Caspian Lowland. It differs somewhat in sandy deserts and other deserts. The typical desert fauna is intermixed with species associated with cultivated land, human settlements, and floodplain forests (tugais). The desert fauna is subjected to harsh

Figure 7. Mountain fauna: (1) bezoar goat (Capra hircus aegagrus), (2) snow vole (Microtus nivalis), (3) the vole Pitymys pitymys, (4) long-clawed mole-vole (Prometheomys schaposchnikowi), (5) chamois (Rupicapra rupicapra), (6) great rosefinch (Carpodacus rubicilla), (7) Caspian snow cock (Tetraogallus caspius), (8) Caucasian snow cock (Tetraogallus caucasicus), (9) Turkestan red pika (Ochotona rutila), (10) Royle’s pika (Ochotona macrotis), (11) Cornish, or red-billed, chough (Pyrrhocorax pyrrhocorax), (12) Guldenstadt’s redstart (Phoenicurus erythrogaster), (13) bar-headed goose (Anser indicus), (14) Malpolon monspessulanus, (15) East Caucasian tur (Capra caucasica), (16) Caucasian black grouse (Lyrurus mlokosiewiczi), (17) Tibetan snow cock (Tetraogallus tibetanus), (18) blue rock thrush (Monticola solitaria), (19) chukar partridge (Alectoris kakelik), (20) ibisbill (Ibidorhyncha struthersii), (21) wall creeper (Tichodroma muraria), (22) argali (Ovis ammon), (23) bearded vulture (Gypaetus barbatus), (24) streaked laughing thrush (Garrulax lineatus), (25) Siberian ibex (Capra sibirica), (26) white-winged grosbeak (Coccothraustes carnipes), (27) stone marten (Martes foina), (28) alpine weasel (Mustela altaica), (29) red marmot (Marmota caudata), (30) Menzbier’s marmot (Marmota menzbieri), (31) Asiatic wild dog (Cuon alpinus), (32) snow leopard (Uncia uncia), (33) markhor (Capra falconeri)

Figure 8. Freshwater fauna. Basins of the Arctic Ocean and the southern seas of the European USSR: (1) blackfish (Dallia pectoralis), (2) Atlantic salmon (Salmo salar), (3) river lamprey (Lampetra tluviatilis), (4) European stone loach (Nemachilus barbatula), (5) minnow (Phoxinus phoxinus), (6) taimen (Hucho taimen), (7) Siberian sturgeon (Acipenser baeri), (8) grayling (Thymallus arcticus), (9) burbot (Lota lota), (10) carp (Cyprinus carpio), (11) European bream (Abramis brama), (12) golden crucian carp (Carassius carassius), (13) sterlet (Acipenser ruthensis), (14) three-spined stickleback (Gasterosfeus aculeatus), (15) peled (Coregonus peled), (16) broad whitefish (Coregonus nasus), (17) pike (Esox lucius), (18) chub (Leuciscus cephalus), (19) common pike perch (Lucioperca lucioperca), (20) sheatfish (Silurus glanis), (21) the crayfish Astacus leptodactylus. Middle Asia: (22) Amu Darya shovelnose sturgeon (Pseudocaphirhynchus kautmanni), (23) common marinka (Schizothorax intermedias), (24) Turkestan catfish (Glyptosternum reticulutum), (25) Balkhash perch (Perca schrenki), (26) naked osman (Diptychus dybowski). Lake Baikal: (27) Baikal seal (Phoca sibirica), (28) the amphipod Axelboeckia carpenteri, (29) the amphipod Garjajewia cabanisi, (30) the sponge Lubomirskia baikalensis, (31) the mollusk Baicalia costata, (32) the mollusk Baicalia godlewskii, (33) yellowwing (Cottocomephorus grewingki), (34) stone sculpin (Cottus kneri), (35) Baikal arctic cisco (Coregonus autumnalis migratorius), (36) Baikal oil-fish (Comephorus baicalensis). Far East: (37) sockeye salmon (Oncorhynchus nerka), (38) coho salmon (Oncorhynchus kisutch), (39) pink salmon (Oncorhynchus gorbuscha), (40) Chinook salmon (Oncorhynchus tshawytscha), (41) chum, or dog, salmon (Oncorhynchus keta), (42) Chinese perch (Siniperca chuatsi), (43) snakehead (Ophicephalus argus), (44) Chinese chebachok (Pseudorasbora parva), (45) skygazer (Erythroculter erythropterus), (46) Chinese sleeper (Perccottus glehni), (47) yellowcheek (Elopichthys bambusa), (48) silver carp (Hypophthalmichthys molitrix), (49) fiddler fish (Leiocassis ussuriensis), (50) Soldatov’s catfish (Silurus soldatova), (51) kaluga (Huso dauricus), (52) Amur sturgeon (Acipenser schrenki), (53) black Amur bream (Megalobrama terminalis), (54) black carp (Mylopharyngodon piceus), (55) Amur false gudgeon (Pseudogobio rivularis), (56) eight-barbel gudgeon (Gobiobotia pappenheimi), (57) Amur pike (Esox reicherti).

conditions, such as high summer and low winter temperatures, aridity, and sparse vegetation. It consists of specialized species.

Among the characteristic animals are several gerbil and jerboa species, the large-toothed suslik (Citellus fulvus), the suslik Spermophilopsis leptodactylus, which is related to the African ground squirrel, the goitered gazelle (Gazella subgutturosa), the Asiatic wild ass (Equus hemionus; very rare), the tiger weasel (Vormela peregusna), the caracal (Felis caracal; rare), the sand cat (Felis margarita), the African wildcat (Felis libyca), and the cheetah, which is now probably extinct.

Birds include Pander’s ground jay (Podoces panderi), the brown-necked raven (Corvus ruficollis), the saxaul sparrow (Passer ammodendri), the desert sparrow (Passer simplex), the desert warbler (Sylvia nana), sandgrouses of the genus Pterocles, and the Houbara bustard (Chlamydotis undulata).

Reptiles abound, including such lizards as Phrynocephalus, the agama Agama sanguinolenta, the desert (or yellow) monitor (Varanus griseus), Eremias, and geckos, and such snakes as Psammophis lineolatus, the sand snake Eryx miliaris, and vipers, namely, the saw-scaled viper (Echis carinatus) and the Levantine viper (Vipera lebetina). Steppe turtles (Agrionemys horsfieldi) abound. Amphibians are found only in the river valleys.

The rich and varied insect world includes many endemic coleopteran species, including several species of the families Tenebrionidae, Scarabeidae, Carabidae, Curculionidae, Oedemeridae (false blister beetles), and Elateridae, as well as many endemic hymenopteran species, including many species of bees, wasps, ants, velvet ants, butterflies, and moths. Termites are characteristic of the region. There are also species common to Transcaucasia and the Crimea and even the tropics. Several solpugid and scorpion species inhabit Middle Asia and have not penetrated the northern regions. There are also a number of arachnids, such as tarantulas and karakurts.

The fauna linked with cultivated areas and the tugais is more varied and includes some unusual forms, for example, the green toad (Bufo viridis), the pond frog (Rana ridibunda), the scincoid lizard Ablepharus, the true pheasant, the bandicoot (Nesokia indica), the wild boar (Sus scrofa), the tugai deer (Cervus elaphus bactrianus), and the jackal (Canis aureus). Central Asia appears to have been the place of origin of the Middle Asian desert fauna, which, in addition to Central Asian species, also includes species of African origin. A special “desert” coloring (sandy and yellow tones) is characteristic of desert vertebrates and many insects.

MOUNTAIN FAUNA. The mountain fauna is highly varied owing to differences in elevation and the rugged terrain. The most typical mountain animals are associated with high elevations. The fauna of the lower belts consists mainly of species of the zone in which the particular mountain system is situated and of the species of the adjacent zones. However, since the principal place of origin of the Eurasian mountain fauna is Central and Middle Asia, the number of high-mountain species in the fauna of an individual mountain system depends on how far the fauna is from the place of origin. Thus, the fauna of the mountains of the Kola Peninsula, the Urals, and the northern part of Siberia differs little from that of the expanses of the plains taiga. The Crimean fauna too is almost entirely lacking in specifically mountain features. Alpine faunistic elements, such as the alpine shrew (Sorex alpinus) and the snow vole (Microtus nivalis), are found in the Carpathians, but in view of the marked predominance of European forest species their role is slight. The high-mountain fauna of the Altai and Saian mountains, for example, the mountain voles (Alticola), the Siberian ibex (Capra sibirica), and the Altai snow cock (Tetraogallus altaicus), is more varied, but its zoogeographic makeup is, in general, typically Siberian and taiga.

The animal world of the Caucasus and the Middle Asian mountains is more varied. The differences in the faunas of the two regions are more pronounced than the similarities. The origin of the Caucasian fauna is closely linked with that of Southwest Asia and Southern Europe. Characteristic mammals are pine mice (Pitymys), the snow vole, various goats, such as the bezoar (Capra hircus aegagrus), the West Caucasian tur (Capra caucasica), the East Caucasian tur (Capra cylindricornis), and the chamois (Rupicarpa rupicarpa), and the endemic long-clawed mole-vole (Prometheomys schaposchnikow). Birds include the Caucasian snow pheasant (Tetraogallus caucasicus), the Caspian snow cock (Tetraogallus caspius), the Caucasian black grouse (Lyrurus mlokosiewiczi), the great rosefinch (Carpodacus rubicilla), and Guldenstadt’s redstart (Phoenicurus erythrogaster). The number of reptile and amphibian species is very large. The insect fauna is one of the richest in the USSR, along with the Middle Asian and Ussuri fauna, and is markedly southern in character.

The fauna of the mountain systems of Middle Asia, with the exception of the Kopetdag, which has the Irano-Transcaucasian type of fauna, is closer to that of the Central Asian highlands. Among the typical animals are the juniper vole (Pitymus juniperus), the vole Microtus pamiris, Royle’s pika (Ochotona macrotis), the Turkestan red pika (Ochotona rutila), the gray marmot (Marmota baibacina), the red marmot (Marmota caudata), Menzbier’s marmot (Marmota menzbieri), several forms of argali (Ovis ammon), the Siberian ibex, and, in some areas, the markhor (Capra falconeri) and the snow leopard. Other animals include two species of Tetraogallus, the ibisbill (Ibidorhyncha struthersii), the bar-headed goose (Anser indica), the white-winged grosbeak (Coccothraustes carnipes), and several species of finches, buntings, and redstarts.

Freshwater fauna. The freshwater fauna of the USSR belongs to two regions in accordance with the zoogeographic zonation of the continental bodies of waters—the Holarctic region and the Amur transitional region.

HOLARCTIC REGION. Of the total number of subregions into which the Holarctic region is subdivided, the fresh bodies of water of the USSR belong to four: the Circumpolar, the Baikal, the Mediterranean, and the Asian Highland subregions.

Circumpolar subregion. The Circumpolar subregion encompasses the basins of rivers emptying into the Arctic and North Pacific oceans. The fauna is very meager, numbering about 100 species of fish, of which the salmonids account for about one-third. Invertebrates are represented either by widespread species or by cold-loving species characteristic of arctic and high-mountain regions. Marine forms, such as the crustacean Mesidotea and various amphipods, are concentrated mainly in the mouths of rivers and in some large lakes. The fauna of the rivers of the Pacific Ocean basin is poorer than that of the rivers of the Arctic Ocean basin.

Baikal subregion. The Baikal subregion consists solely of Lake Baikal, whose fauna is very rich, numbering about 1,000 species, and extremely unusual. More than three-fourths of the species are endemic. Among the typical fish are two endemic families of Baikal gobies, the Baikal oil-fish (Comephorus), the arctic cisco (Coregonus autumnalis), and the European stone loach (Nemachilus barbatulo). The Baikal seal (Phoca sibirica) is a typical mammal. Invertebrates originated mainly from ancient Tertiary freshwater fauna, whose survivors gave rise to numerous new forms in the lake. Amphipods, which number about 300 species, endemic gastropod mollusks and sponges, and numerous oligochaetes and ciliated worms (turbellarians) are characteristic. Groups of freshwater animals that are widely distributed elsewhere are not found in Lake Baikal.

Mediterranean subregion. The Mediterranean subregion encompasses the basins of rivers emptying into the Baltic and Black seas, the Sea of Azov, and the Caspian and Aral seas. The dominant species are from the families Cyprinidae, as well as from the families Acipenseridae, Clupeidae, and Gobiidae. Salmonids are comparatively rare. Among the mollusks, members of the genera Theodoxus, Melanopsis, and Lithoglyphus dwell only here and do not occur in the Circumpolar subregion. Crustaceans include crayfish, freshwater crabs, and some genera of Caspian amphipods. The fauna is most abundant and varied in the basin of the Black, Aral, and Caspian seas, where the freshwater lakes and rivers abound in marine elements.

Asian Highland subregion. The Asian Highland subregion encompasses the basin of Lake Balkhash, as well as the upper reaches of the Amu Darya, Syr Darya, and Zeravshan rivers. The fauna is meager but quite unusual. Among the characteristic fish are members of the genera Schizothorax, Diptychus, Nemachilus, and Glyptosternum. The family Cyprinidae is represented by a large number of species. Unique species of Lymnaeidae, Planorbidae, and Bithynia are typical mollusks.

Figure 9. Marine fauna. Caspian Sea: (1) the crustacean Didacna trigonoides, (2) Caspian seal (Phoca caspica), (3) stellate sturgeon (Acipenser stellatus), (4) roach (Rutilus rutilus), (5) Caspian shad (Caspialosa caspia), (6) the crustacean Mesidotea entomon caspica, (7) Caspian tiul’ka (Clupeonella delicatula caspia). Black Sea: (8) the crab Pachygrapsus marmoratus, (9) striped mullet (Mugil cephalus), (10) the jellyfish Rhizostoma pulmo, (11) the oyster Ostrea edulis, (12) the mussel Mytilus edulis, (13) bottle-nosed dolphin (Tursiops truncatus), (14) Atlantic mackerel (Scomber scombrus), (15) tub, or yellow, gurnard (Trigla lucerna), (16) the red mullet Mullus barbatus, (17) horse mackerel (Trachurus trachurus), (18) sea horse (Hippocampus guttulatus microstephanus), (19) rascasse (Scorpaena porcus). Northern seas: (20) beluga (Delphinapterus leucas), (21) killer whale (Orcinus orea), (22) narwhal (Monodon monoceros), (23) Atlantic cod (Gadus morhua), (24) arctic cod (Boreogadus saida), (25) pollack (Gadus virens), (26) the crab Hyas araneus, (27) the skate Raja radiata, (28) the sea urchin Strongylocentrotus droebachiensis, (29) the brittle star Gorgonocephalus eucnemis, (30) hermit crab (Pagurus pubescens), (31) the shrimp Sabinea septemcarinata, (32) Atlantic wolffish (Anarhi lupus), (33) Greenland shark (Somniosus macrocephalus). Far Eastern seas: (34) cutlass fish (Trichiurus iaponicus), (35) Far East pilchard (Sardinops sagax melanosticta), (36) the herring Clupea pallasi, (37) the mollusk Rapana venosa, (38) finback (Balaenoptera physalus), (39) sperm whale (Physeter catodon), (40) Pacific saury (Cololabis saira), (41) Atka mackerel (Pleurogrammus monopterygius), (42) walleye pollock (Theragra chalcogramma), (43) glassfish (Salangichthys microdon), (44) Atlantic halibut (Hippo-glossus hippoglossus), (45) the plaice Liopsetta pinnifasciata, (46) the squid Ommatostrephes sloani, (47) the shrimp Pandalus hypsinotus, (48) the surf clam Mactra sachalinensis, (49) the oyster Mizuhopecten jessoensis, (50) the trepang Stychopus japonicus, (51) king crab (Paralithodes camschatica).

AMUR TRANSITIONAL REGION. The Amur transitional region encompasses the basins of the Ussuri and Amur rivers, as well as the lakes and rivers of the island of Sakhalin and the Kuril Islands. Its fauna includes not only endemic forms but also elements of two neighboring regions, the Holarctic in the north and the Sino-Indian in the south. Among the southern fish species are the snakehead (Ophicephalus argus), the zheltoshchek, or yellowcheek (Elopichthys bambusa), the grasscarp, or white amur (Ctenopharygodon idella), and the silver carp (Hypophthalmichthys molitrix), while Pacific salmons (Oncorhynchus), graylings (Thymallidae), the burbot (Lota lota), lampreys (Petromyzon), and an endemic pike species are typical northern animals. Because of historical conditions, the fauna has come to resemble somewhat the fauna of the Mediterranean subregion.

Marine fauna. The northern seas of the USSR—from the Barents Sea to the Chukchi Sea (except the extreme southwestern part of the Barents and the shallow southern part of the White Sea)—and the northern part of the Bering Sea constitute the Arctic zoogeographic region. These seas are characterized by relatively few species (about 1,500 species of free-living animals), a small number of commercially valuable fish and invertebrates, and a substantial admixture of saltwater forms in the southern coastal areas of the Siberian seas. The southwestern part of the Barents Sea and the southern shallow waters of the White Sea belong to the North Atlantic boreal region, which is much richer in species and individuals, and most of the commercially valuable fish of these seas are boreal. The Baltic Sea belongs to the same region, but owing to its low salinity its fauna is extremely meager, only about 100 species within USSR waters, primarily highly euryhaline boreal species and arctic relicts.

The Bering Sea, the Sea of Okhotsk, the Sea of Japan, and the Pacific waters near the Kuril Islands and Kamchatka belong to the North Pacific boreal region, whose fauna is extremely rich, numbering about 5,000 species, and independent; many arctic, arctic-boreal, and amphiboreal species originated from the region. In addition to boreal and arctic-boreal species, some subtropical and subtropical-southern boreal species occur in the extreme southern part of the Far East (Petr Velikii and Post’et bays, Moneron Island, Busse Lagoon in Aniva Gulf, and the southern part of the Kuril Ridge).

The Black Sea and the Sea of Azov belong to the Mediterranean-Lusitanian region, but owing to low salinity and marked cooling in winter, their fauna is very meager, approximately one-third that of the Mediterranean region. The Black Sea and the Sea of Azov are reached only by very hardy species, which also live in the boreal Atlantic and thus impart uniquely Atlantic features to the Black Sea fauna. In addition to species common to the Mediterranean, there are also Pontic-Caspian saltwater relicts and a few originally freshwater species. The Black Sea, excluding the freshwater parts, has about 1,500 free-living species, while the Sea of Azov has about 350 species.

The Caspian Sea and the coastal lagoons of the Black Sea and the Sea of Azov belong to the Pontic-Caspian saltwater region, whose principal fauna consists of relicts, descendants of Sarmatian (Upper Miocene) fauna, as well as forms that were originally freshwater forms, fish introduced from the Mediterranean, and a few arctic immigrants. The fauna of the Caspian, which numbers about 650 species, is much poorer than that of the Black Sea. The Aral Sea fauna is even poorer, numbering about 220 species and consisting mainly of freshwater forms intermixed with some Caspian and Mediterranean forms. The Aral Sea is an unusual salt-water province of the Palaearctic region.

Bibliography

The USSR is one of the world’s leading countries in commercial fish and game resources, which serve as the basis for such important branches of the economy as fishing, seal hunting, whaling, and game hunting. Of the 125,000–130,000 animal species that inhabit the USSR, many are of great practical importance.

A distinction is made between beneficial animals and destructive animals. In addition to animals that are directly beneficial and destructive, there are animals that are indirectly beneficial to man (various birds, mammals, reptiles, amphibians, and predatory insects that destroy destructive insects, predatory mammals, owls and diurnal predatory birds that feed on mouselike rodents, pollinating insects, and soil-forming animals) and animals that are indirectly harmful (for example, birds that feed on useful insects). The relationship between animals and man is often highly complex and contradictory. For example, wolves attack domestic animals, yet at the same time they are hunted for their fur and themselves perform a beneficial role by destroying sick and weak wild animals. Some rodents, for example, susliks, inflict considerable damage on the economy, yet at the same time they serve as food for several valuable furbearers, such as the weasel Putorius eversmanni and the stone marten (Martes foina).

In recent decades (1930’s through 1960’s), the range of distribution of many animal species decreased in size, both as a result of pursuit by man and the deterioration of the habitats, and consequently a number of animals have become quite rare, such as the goitered gazelle (Gazella subgutturosa). Other animals dispersed widely, chiefly with the help of man, and their numbers increased, for example, the sable, the elk, the beaver, and the saiga (Saiga tatarica). Many have once again become game animals. Some endemic species were brought to new areas and acclimatized there, for example, the raccoon dog and the Japanese deer (Cervus nippon), which were moved from the Far East to the European part of the USSR, and the squirrel, which was relocated from Siberia to the Crimea and the Caucasus. Other species, such as the muskrat, coypu, and the American mink, were imported from America.

Beneficial animals. Useful animals include various game animals and birds, as well as commercially valuable fish, marine mammals, and some aquatic invertebrates.

COMMERCIALLY VALUABLE ANIMALS. The USSR has more than 90 species of furbearers and wild ungulates, but only a few dozen are of any major economic importance. Products obtained through hunting, including medicinal and industrial raw materials, are valued at about 140 million rubles annually. About 30,000 regular and more than 200,000 seasonal hunters work in specialized hunting areas alone. The importance of sport hunting is increasing, with a total of about 2.5 million sportsmen (1975).

Furbearers. About 70 species of fur-bearing animals inhabit the USSR. They are the most important animals hunted commercially, although wild ungulates are steadily gaining increasing importance with both commercial and sport hunters. Twenty million pelts, worth 26 million rubles, were purchased by the state in 1975. The sable, squirrel, muskrat, fox, and arctic fox are the main fur-bearing species. The rest are of secondary importance, although about 20 species are hunted by commercial and sport hunters, including the mole, the European, or pine, marten (Martes martes), the stone marten, the ermine, the weasels Putorius putorius and Putorius eversmanni, the Siberian weasel (Mustela sibirica), the European mink (Mustela lutreola), the American mink (Mustela vison), the otter, the brown bear, the wolf, the raccoon dog, the lynx, various hares, the beaver, and various susliks.

The sable, a typical animal of the Siberian taiga, was threatened with extinction by the beginning of the 20th century. It was designated a protected species and by the 1960’s and 1970’s had regained its former range. The total number varies (1970’s) between 500,000 and 600,000, of which 60 percent are concentrated in the mountains of Southern and Central Siberia. The average annual take in the period 1959–69 was more than 170,000. The total number taken declined slightly in the 1970’s.

The squirrel is the second most important furbearer. Its numbers decreased sharply in the 1920’s and 1930’s. In the 1930’s about 14–15 million pelts were procured annually. The squirrel is hunted in the RSFSR, mainly in Siberia; for example, in 1975, Irkutsk Oblast accounted for 16 percent of the pelts procured, Yakutia for 14 percent, and Krasnoiarsk Krai for 12 percent. Only 3.4–4.8 million pelts were procured annually in the 1970’s, probably because of poor organization of work and a decline in the squirrel population as a result of a decrease in the area of mature coniferous forests and an increase in the population of sables, which attack squirrels.

The muskrat is a North American rodent, whose acclimatization in the USSR was begun in 1928. About 2,500 animals were imported, and shortly thereafter more than 280,000 of their offspring were released into the wild. The muskrat dispersed widely in the course of the next 30 years. The size of its new area of distribution in Eurasia soon exceeded the area of distribution in America, and the muskrat became the third most important fur-bearer in the USSR and, in years of a low squirrel population, the second most important. In the period 1955–57, the muskrat population peaked and then declined for a number of reasons, including overhunting, insufficient supply of food plants, disease, the drainage of lands inhabited by the muskrat, and the drying up of lakes and rivers. In 1975,1.4 million pelts were procured, with the RSFSR accounting for 88 percent, Kazakhstan for 10 percent, and the Ukraine for 1.1 percent.

The fox is found in all open and cultivated landscapes except the tundra. It avoids dense forests and is encountered in the taiga zone only in river valleys. About 54 percent of the animals are concentrated in the forest and forest-steppe zones and 22.7 percent in the forest zone, including 10 percent in the taiga and 18.2 percent in the Middle Asian deserts (1966–70). The fox population is increasing with the development of agriculture, reaching 1.5 million in a favorable year. About 460,000 pelts were procured annually in the 1960’s and 1970’s. In 1975, the RSFSR accounted for 40 percent of the country’s total procurement, Middle Asia for 33 percent, and the Ukraine for 12 percent. In Kazakhstan the most experienced hunters kill about 350 foxes in one season; the average take is several dozen. Foxes also serve a beneficial purpose, since they destroy harmful rodents (about 3,000 voles and mice a year per fox). However, they are destructive in areas where game birds are raised.

The arctic fox accounts on the average for 90–95 percent of the total value of furs obtained in the tundra and 7–8 percent of the total value of the entire fur trade in the USSR. In a favorable year, its population may number half a million individuals, and in poor years, 80,000–100,000. The total annual take is comparatively stable, numbering 52,000–110,000 (1960’s and 1970’s). The main reason for the fluctuations in the arctic fox population is sharp changes in the abundance of its principal food—the lemming. Arctic foxes are hunted chiefly in the northern part of Western Siberia (29–34 percent), in the northern part of Krasnoiarsk Krai (25–33.5 percent), and in Yakutia (22–32 percent).

The European mole is an inexpensive and common furbearer, inhabiting the southern forest zone and the forest steppe of the European USSR. A total of 5.9–13.4 million pelts were procured annually in the period 1971–75. The RSFSR accounted for 90 percent, and the Ukrainian and Byelorussian SSR’s, for 10 percent.

The pine marten inhabits the forests of the European USSR, and the stone marten, the open and mountainous areas of the southern part of the European USSR, Transcaucasia, and Middle Asia. The pine marten population varies from 200,000 to 300,000, while the stone marten population numbers about 100,000. In the period 1965–72, 80 percent of the pelts from both marten species were procured in the RSFSR, 8.8 percent in Transcaucasia, 4 percent in Byelorussia, and 3.7 percent in the Ukraine. The pine marten is taken primarily in the RSFSR and the Byelorussian SSR, and the stone marten, in Transcaucasia and the Ukraine.

The ermine is found almost everywhere. About 95,000–141,000 pelts were procured annually in the period 1971–75, of which up to 98 percent were taken in the RSFSR (58 percent in Yakutia, 10 percent in Tiumen’ Oblast, and 7 percent in Krasnoiarsk Krai).

The brown bear is hunted chiefly by sport hunters. There are about 100,000 bears (1970’s), of which about 96,000 are in the RSFSR, about 3,000 in the mountains of Transcaucasia and Middle Asia, and less than 1,000 in the Ukraine, Byelorussia, and the Baltic Region.

The wolf is characteristic of open and virtually snowless landscapes; it avoids dense forests. When present in large numbers, it poses a threat to domestic and beneficial wild animals, and consequently the control of the wolf population is essential. In 1973 there were about 50,000 wolves, of which 13,000–14,000 were in the RSFSR, about 30,000 in Kazakhstan, 500 in the Ukraine, 1,000 in Byelorussia, and 5,000 in Middle Asia. Wolves are particularly destructive in Kazakhstan.

Wild ungulates. About 20 species of wild ungulates inhabit the USSR, but only six species are of practical importance.

The elk inhabits almost the entire forest zone; it is also found in the forest tundra and tundra and, in the south, in the forest steppe and island forests. In 1970 the elk population totaled 700,000, of which 500,000 were in the RSFSR, 133,000 in the Ukraine, 23,000 in Byelorussia, 10,000 in Estonia, 17,000 in Latvia, 7,000 in Lithuania, and 1,000 in Kazakhstan. About 60,000–70,000 elks, including 30,000 actually accounted for, are taken annually. The elk is hunted by both commercial and sport hunters. In some parts of the RSFSR, the value of the products obtained from the elk exceeds that of the fur trade in these regions.

The wild reindeer inhabits the tundras and most of the taiga. It was almost exterminated by the beginning of the 20th century, but by the 1970’s the population had increased to 600,000–700,000. The largest herd, which numbers about 350,000 individuals, is concentrated on the Taimyr Peninsula; about 200,000 live in Yakutia and 14,000 on the Kola Peninsula. The reindeer in Yakutia and on the Taimyr Peninsula are not being sufficiently exploited. About 60,000–70,000 are taken annually (1970–75).

The red deer is an important game animal, hunted by both commercial and sport hunters. It is widely distributed in mixed and broad-leaved forests of the European USSR; it is also found in some parts of the tugai and mountain forests of the Asiatic part of the USSR. There were 120,000–130,000 animals in 1972, up to 50 percent of which were in game preserves. Of the 110,000–120,000 deer in the RSFSR, 87 percent are in the Asiatic part (more than 60 percent in the mountains of Southern Siberia and 20 percent in the Far East). About 15,000–17,000 are taken annually (1970–73). Red deer—maral and wapiti—are bred on specialized farms to obtain panty (unossified deer antlers used as a source of medicinal preparations).

The roe deer inhabits the forest steppe, wooded fields, and the virtually snowless southern part of the forest zone. It survives without difficulty in a cultivated agricultural landscape. The roe deer is a promising and valuable species for sport and commercial hunting. The population (1970) varies from 600,000 to 900,000 individuals, of which 166,000 inhabit the Baltic Region, 20,000 Byelorussia, and 123,000 the Ukraine. Its numbers are growing in the European part of the country, where it is most effectively protected. In the 1960’s, at least 65,000 (estimate) were taken annually.

The wild boar is widely distributed but is rarely found north of the southern taiga. The population numbered several hundred thousand individuals in the 1970’s. More than 25 percent live in the southern regions of the Far East and about 25 percent in the Northern Caucasus. A large and ever-increasing number of wild boar are found in the southern and central parts of the European USSR. Although it appears to be a promising game animal, it is destructive to agriculture. At least 30,000–40,000 are killed annually (1970’s).

The saiga is characteristic of the dry steppes and semideserts of Kazakhstan and the Caspian Region. It had become almost extinct by the beginning of the 20th century, but owing to protective measures, its population increased sharply and in 1974 numbered 1.5 million individuals in Kazakhstan and 400,000 in the RSFSR.

Among other species, the musk deer is of particular importance. It inhabits the mountains of Siberia and yields, in addition to meat and hides, valuable musk. Its population numbers about 300,000 (1970); the deer is little exploited.

About ten species of mountain ungulates are few in number, including the argali (Ovis ammon), turs (Capra caucasica and Capra cylindricornis), the chamois (Rupicarpa rupicarpa), the Siberian ibex (Capra ibex), and the bighorn sheep (Ovis canadensis), and two desert dwellers—the goitered gazelle and the Asiatic wild ass (Equus hemionus). The hunting of all these animals is prohibited or greatly curtailed.

GAME BIRDS. About 100 species of game birds inhabit the USSR. The annual take in the period 1971–75 was as follows: waterfowl, 33.1 million; tetraonids, 9.2 million; quails, 4.1 million; and other game birds, 5.1 million. The total annual weight of the meat from game birds is 42,100 tons.

Waterfowl. Waterfowl are the most traditional and popular game birds. At the end of the 1960’s, 45–55 million waterfowl (autumn population) were nesting in the USSR, primarily in the tundra and forest tundra (20–25 million), where almost all the geese (1.5 million) are concentrated. Among ducks, the most numerous are the old-squaw (Clangulla hyemalis), which numbers 2 million, the king eider (Somateria spectabilis), and the scaup (Aythya marilla). In the taiga, the autumn duck population numbers 6–7 million; the common species include the pintail duck (Anas acuta), the mallard (Anas platyrynchos), and the true teal (Anas creced). In the mixed and broad-leaved forests of the European USSR and the Far East, it numbers 4.5–5.5 million; the main species are the mallard, the true teal, the garganey (Anas querquedula), the pintail duck, the shoveler (Anas clypeata), and the widgeon (Anas penelope). In the forest steppe and steppe, where the lakes and rivers abound in waterfowl, 9.5–11 million birds remained by the mid-1970’s, while in semidesert and desert bodies of water 5–5.6 million remained. Their numbers have decreased not only as a result of hunting and environmental changes in the nesting areas, but also as a result of the destruction of the birds while in flight and at the wintering areas, which are often outside the USSR.

Gallinaceous birds. Of practical importance are the willow ptarmigan (Lagopus lagopus), the rock ptarmigan (Lagopus mutus), the black grouse (Lyrurus tetrix), the hazel hen (Tetrastes bonasia), the common capercaillie (Tetrao urogallus), the black-billed capercaillie (Tetrao parvirostris), and the quail (Coturnix coturnix). The significance of gallinaceous birds compared to waterfowl is underestimated because commercial hunting has declined and sport hunting is not well developed. Gallinaceous birds number in the tens of millions. About 10 million were taken annually (late 1960’s).

The willow and rock ptarmigans, which are most numerous in the southern tundra, account for about 80 percent of the centralized procurement of gallinaceous birds, of which there are about 20–30 million. The hazel hen and the common and black-billed capercaillies are taiga species, numbering approximately 30–40 million, most of which are concentrated in the European north and in Western Siberia. The common capercaillie is found west of the Enisei River, and the black-billed capercaillie, east of the Enisei; there are about 2–3 million capercaillies. The grouse population has declined; the autumn population is about 27 million (mid-1960’s). The number of Hungarian partridges (Perdix perdix), pheasants, and quails has also decreased considerably; nevertheless, in the autumn quails are still widely hunted in the southern European USSR.

Other game birds include many species of Limicolae, especially the woodcock (Scolopax rusticola) and various snipes of the genus Gallinago, including the great snipe (Gallinago media).

FRESHWATER ANIMALS. The freshwater fauna of the USSR is rich and varied; there are 27 fish families, encompassing 301 species. Although fish catches in inland waters are approximately nine times less than the catches in the seas, freshwater fish are important as a source of food. The bulk of the fish caught are chastikovye fish (fish caught in fine-mesh nets), both large and small fish. The former include a number of cyprinids, such as the ide (Leuciscus idus) and European bream (Abramis brama), as well as the common pike perch (Lucioperca lucioperca), the pike (Esox lucius), and the burbot (Lota lota). The latter are primarily cyprinids, such as the crucian carp (Carassius carassius), the roach (Rutilus rutilus), and the dace (Leuciscus leuciscus), as well as the Eurasian perch (Perca fluviatilis) and the ruff (Acerina cernua).

Acipenseroids are the most valuable fish. Only the sterlet (Acipenser ruthensis) and the Old World shovelnose sturgeons are purely freshwater species. The sterlet inhabits primarily the rivers of the European USSR and the Ob’ and Enisei river basins, while the shovelnose sturgeons inhabit the Amu Darya and Syr Darya. Among the salmonids, freshwater trout of the genera Salmo and Oncorhynchus, the European stone loach (Nemachilus barbatulo), and the taimen (Hucho taimen) are purely freshwater species, while fish of the genus Coregonus are mostly freshwater. The trouts are freshwater forms of the migratory salmon trout (Salmo trutta) and inhabit the cold-water lakes and rivers of Europe. The stone loaches are found in most bodies of water in the Far North; the lake form—the lake char (Salvelinus lepechini)—lives in the northern lakes of Siberia, as well as in Lakes Ladoga and Onega. The taimen and the lenok (Brachymystax lenok) live in the northern rivers of Eurasia. The genus Coregonus includes such major commercial fish as various ciscos, the tugun (Coregonus tugun), the arctic cisco (Coregonus autumnalis), the common whitefish (Coregonus clupeiformes), the peled (Coregonus pelea), the broad whitefish (Coregonus nasus), the muksun (Coregonus muksun), and the round white-fish (Coregonus cylindraceus). The European cisco (Coregonus albulo) and the common whitefish live in the northern European USSR; the remaining species of the genus Coregonus live in Siberia, where they are unusually varied and numerous. The ichthyo-fauna is changing radically because of the sharp increase in the number of reservoirs. One of the most important economic goals is to transform the reservoirs into highly productive fisheries. Among the large chastikovye fish in most reservoirs of the European USSR, the European bream and occasionally the pike are particularly numerous. Large stocks of various whitefish (peled, common whitefish, broad whitefish) can be created in the major reservoirs of Siberia.

Pond fish culture, an intensive form of fish culture that helps boost the productivity of lakes and rivers, is playing an increasingly important role in the Soviet fishing industry. It is mainly concerned with raising domesticated carp, as well as the grasscarp, or white amur (Ctenopharyngodon idella), the bighead carp (Aristichthys nobilis), and the rainbow trout (Salmo gairdnerii). Pond fish catches increased by a factor of 5 in the period 1955–70. Pond fish production rose from 630,000 quintals in 1970 to 1,368,700 quintals in 1975. The combined raising of two and even three species is now routine. The trout, the peled, and other species are also bred. Sport fishing is a major pastime in densely populated parts of the country; for example, in the city of Moscow and Moscow Oblast alone, there are about 1 million sport fishermen.

The preservation and restoration of fish stocks are dependent on the solution of such problems as lowering the water level in the Caspian Sea and increasing the salinity of the Sea of Azov, as well as problems related to the implementation of ameliorative and other measures and the construction of hydroengineering structures on rivers, lakes, and reservoirs.

Characteristics of freshwater fish stocks in individual regions. Lakes Ladoga and Onega are very important in the northern part of the European USSR. At the end of the 1960’s, 70 percent of the catches in Lake Ladoga consisted of smelts, small ciscos, the Eurasian perch, the ruff, the roach, and the silver bream (Blicca bjoerkna). The annual commercial fish catch in the most important river, the Pechora, is 20,000 quintals, about 70 percent of which consists of such valuable fish as salmons and graylings. In some years, as much as 7,500 quintals of Atlantic salmon (Salmo salar) are caught here, which constitutes 60 percent of the national catch. Most of the valuable fish, including the arctic cisco, the nelma (Stenodus leucichthys nelma), the European cisco, the common whitefish, the broad whitefish, and the peled, are caught in the lower Pechora. In the upper Pechora are the spawning grounds of most of the country’s Atlantic salmon.

In the central part of the European USSR, the ichthyofauna has undergone fundamental and frequently irreversible changes, but the fish stocks are still quite substantial. The most promising sources are the rivers and lakes of the Baltic Sea basin, where salmonids abound, including the Chudskoe whitefish (Coregonus lavaretus maraenoides), the Volkhov whitefish (Coregonus lavaretus baeri), the European cisco, the lacustrine smelt (Osmerus ereplanus ereplanus morpha spivinchus), and the common Atlantic salmon (Salmo salar). The fish of the Dnieper and Volga river basins are of little value, possessing only local significance.

In the southern part of the European USSR, there are no large lakes, fishing in rivers is poorly developed (except in the lower reaches), and the fishing industry is part of the ocean fishing industry. Common freshwater species include the European bream, the pike perch, the pike, the roach, the wild carp (Cyprinus carpio), the blue bream (Abramis ballerus), the saber carp (Pelecus cultratus), the ide, and the perch. Of particular importance are reservoirs, in which the feeding conditions are favorable for the rapid growth of many valuable fish, such as the wild carp, the European bream, and the pike perch. The fish productivity in such reservoirs is 2–60 kg/hectare (kg/ha) or more, and in the early 1960’s more than 200,000 quintals of fish were caught there. Pond fish culture involving the use of inferior and artificial bodies of water is being successfully developed. The principal fish raised is the domesticated carp, along with the grasscarp, the European bream, and even the peled. In the Ukraine, 436,000 quintals of pond fish were produced in 1975. The bulk of the crayfish is caught in the southern part of the European USSR (1,450 quintals in the Tsimliansk, Kakhovka, and Volgograd reservoirs in 1964).

Pond fish culture is developing in the Caucasus, especially in Azerbaijan and Georgia. The fish productivity of the reservoirs on the Manych River is substantial. Lake Sevan is the most important lake; the Sevan trout (Salmo ischchan) is raised in hatcheries.

Endemic genera are characteristic of the lakes and rivers of Kazakhstan and Middle Asia: Schizothorax, Diptychus, and Nemachilus. The basis of the catches in Lake Balkhash is the acclimatized wild carp and the endemic balkhash perch (Perca schrenki; 80,000–100,000 quintals caught annually in the 1950’s). Marinkas and osmans are typical of mountain lakes and rivers. The roach, the ide, the crucian carp, and barbels are widespread in the rivers. Pond fish culture is most developed in Uzbekistan. About 18,000 quintals of pond fish were obtained in Uzbekistan and Kazakhstan in 1965 and 95,000 quintals in 1975.

Western Siberia is the principal fishing region of Siberia, accounting for more than 70 percent of all the fish caught in Siberia (600,000–700,000 quintals annually at the end of the 1960’s). The catches in the Ob’ and Irtysh river basins are eight to ten times greater than those in the Lena or Enisei river basins because of the developed floodplain and the large number of floodplain lakes and rivers. The principal fish caught are various whitefish, the nelma, and acipenseroids. Whitefish are the most valuable. The Ob’ river basin accounts for 52 percent of all the whitefish caught in Siberia. Whitefish catches in Tiumen’ Oblast increased between 1969 and 1974 from 46,600 to 95,600 quintals. The relative share of chastikovye fish—cyprinids [ide, roach, dace, crucian carp, tench (Tinca tinca)], the pike, the burbot, the perch, and the ruff—is large. More than 100,000 quintals of pike, 25,000–40,000 quintals of ide, about 100,000 quintals of burbot, and about 60,000 quintals of ruff are caught in the most favorable years.

Central Siberia encompasses almost the entire basin of the Enisei basin (one of the five largest rivers with respect to the size of fish stocks), which is famous for its acipenseroids and salmonids. Its fish productivity is low, 2.7–5.2 kg/ha. The share of valuable fish in the catches is particularly considerable north of the Turukhan River, constituting 60–94 percent of all the catches (common whitefish, muksun, arctic cisco, cisco). In the middle and lower reaches of the Enisei, the burbot, the pike, the perch, and various cyprinids (dace, roach) make up the bulk of the catches. The large arctic lakes in northern Krasnoiarsk Krai are important. Whitefish and other salmonids make up about 90 percent of the catches. The stocks of the main commercial fish of the Enisei (acipenseroids and salmonids) were largely restored by the beginning of the 1970’s as a result of extensive conservation measures.

The principal body of water in the mountainous part of Southern Siberia is Lake Baikal, which accounts for about 70 percent of the fish catch in the region. Of commercial significance are the arctic cisco (39,400 quintals in 1961), the roach, the Eurasian perch, the pike, the crucian carp, various gobies, and the burbot.

The Baikal seal (Phoca sibirica) is also caught (2,500–3,000 animals a year from a population of 25,000–30,000).

In Yakutia, the main fishing waters are the Lena River, whose lower reaches are inhabited by the Siberian sturgeon (Acipenser baeri), the taimen, the nelma, and various whitefish. The river delta has been designated a fish sanctuary because of the decline in the population of a number of valuable fish species. There are many lakes (more than 650,000, with a total area of 6.7 million ha), but only 5,700 quintals of fish, primarily crucian carp, were caught in the 1960’s. The total supply of commercial fish in Yakutia has been estimated at 90,000–100,000 quintals.

In the southern part of the Far East and Primor’e Krai, the Amur River is the principal freshwater body. Its commercial fish stocks long consisted chiefly of Pacific salmon, which come to spawn here. Their fishing is now prohibited, as well as the fishing of local acipenseroids, such as the kaluga (Huso dauricus) and the Amur sturgeon (Acipenser schrenki). Chastikovye fish, such as the wild carp, the grasscarp, the silver carp (Hypophthalmichthys molitrix), the skygazer (Erythroculter erythropterus), the European bream, the yellowcheek (Elopichthys bambusa), the Amur pike (Esox reicherti), the sheatfish (Silurus glanis), and the crucian carp, constitute the bulk of the fish catches. A few whitefish, taimens, lenoks, and graylings are found in the catches. About 100,000 quintals of fish were caught annually at the beginning of the 1970’s. The small rivers that empty into the Sea of Japan and the Sea of Okhotsk are important spawning grounds of migratory salmon.

MARINE ANIMALS. Fish, invertebrates (crustaceans, mollusks, echinoderms), and mammals are among the marine animals of the inland waters and adjacent marginal seas of the USSR that are of commercial significance. Fishing and whaling outside the territorial waters of the USSR are also very important economically.

Fish. About 250 species are commercially important. Most of the catches consist of gadids and clupeids; the former include the walleye pollock (Theragra chalcogramma), the Atlantic cod (Gadus morhua), the haddock (Melanogrammus aeglefinus), and the pollack (Gadus vireni), while the latter include various herrings and sprats. Osmerids, such as the capelin (Mallotus villosus) and smelts, are somewhat less important, as are pleuronectids and scorpaenids. Migratory fish that fatten in the sea but reproduce in rivers (acipenseroids and salmonids) are particularly valuable.

The USSR leads the world in the abundance and variety of acipenseroids; there are 13 species, including the beluga (Huso huso), the kaluga, and the ship sturgeon (Acipenser nudiventris) the stellate sturgeon (Acipenser stellatus), and five other acipenseroid species. The Caspian Sea is the main source of acipenseroids. Catches are strictly regulated and are even prohibited in some places; as a result, the population, which by the beginning of the 20th century had been nearly exterminated as a result of rapacious fishing, has begun to grow. Considerable attention is given to the artificial breeding of young acipenseroids in order to ensure their reproduction, since they have been deprived of their natural spawning grounds as a result of the construction of various hydroengineering structures. In 1975, 110 million young belugas, common sturgeons (Acipenser sturio), and stellate sturgeons were bred in sturgeon hatcheries.

The most important salmonids are the Pacific salmon, including the pink salmon (Oncorhynchus gorbuscha), the chum, or dog, salmon (Oncorhynchus keta), the sockeye salmon (Oncorhynchus nerka), and the chinook salmon (Oncorhynchus tschawytscha), which spawn in the rivers of the Far East. The hatcheries of the Far East release more than 800 million chum salmon and pink salmon fry every year. The most valuable Atlantic salmon—the common Atlantic salmon (Salmo salar) and the salmon trout (Salmo trutta)—fatten in the North Atlantic but spawn in the rivers of Northern Europe, including the rivers of the USSR.

Invertebrates. Crustaceans are commercially important. The king crab (Paralithodes camtschatica) constitutes 80 percent of the world production of canned crabmeat; it is prepared on floating canneries. The main concentrations are found off western Kamchatka. Attempts are under way to acclimatize crustaceans in the Barents Sea. The shrimp industry is well developed in the Far East and in the Black Sea. Mollusks (oysters, mussels, pectens, squids) and echinoderms (sea urchins, trepangs) are also harvested.

Mammals. The northern part of the Pacific is the only region in the northern hemisphere where whaling is carried on. The animals are hunted in the open sea by the USSR and Japan. Whaling has been prohibited in the northern part of the Atlantic since 1938. The USSR is a member of the International Whaling Commission, which sets annual quotas for the number of whales taken. Strict measures to regulate the industry have resulted in an increased whale population in the northern part of the Pacific Ocean. Delphininae, primarily the common dolphin (Delphinus delphi), were hunted in the Black Sea before the practice was banned in 1966, and by the early 1970’s the population numbered 200,000. The beluga (Delphi nepterus leucas) can be hunted in several arctic regions and in the Far East.

Among the pinnipeds, the principal animal hunted is the Greenland seal (Tursiops truncala; population 3 million in 1928 and 500,000–600,000 in 1974), a small number of which are taken in the Barents and White seas (the USSR and Norway together account for 30,000–40,000 animals per year). Their hunting was prohibited in 1965, and their numbers have gradually increased. The limited hunting of whitecoats—young seal pups—was authorized in 1972. The ringed seal (Pusa hispida) is also hunted in the arctic (about 10,000 a year). Small numbers of the bearded seal (Erignathus barbatus) were taken before 1970. The ringed seal (population in 1974 about 800,000) and, less commonly, the Pacific harbor seal (Phoca vitulina), the ribbon seal (Phoca fasciata), and the bearded seal are hunted in the Far Eastern seas (total number, 735,000 individuals). Their hunting is limited to 65,000 per year.

Walruses are hunted only in the northern part of the Far East. The indigenous inhabitants of Chukotka and Alaska are permitted to kill 3,000–3,500 animals per year. Whitecoats of the Caspian seal can be hunted on a small scale. The number of Far Eastern eared seals, such as the northern fur seal (Callorhinus ursinus) and Steller’s sea lion (Eumetopias jubatus), is insignificant. Northern fur seals were almost completely exterminated by the beginning of the 20th century. In 1957, the USSR, the United States, Canada, and Japan adopted a temporary convention for the protection of northern fur seals in the northern part of the Pacific. Only strictly regulated hunting was permitted along the coast at the beginning of the 1970’s. The USSR accounts for 15,000–20,000 per year, and the United States, for 50,000–60,000. The northern fur seal population in the USSR in the mid-1970’s was about 200,000. Steller’s sea lion in USSR waters numbers (1970’s) 40,000–45,000. A small number (6,000–8,000) are taken by local inhabitants.

Characteristics of the fauna of inland waters and adjacent seas. The Barents and White seas are commercially important. There are 114 species in the Barents Sea, of which the following are of commercial value: the cod, the haddock, the pollack, fish of the genus Sebastes, the Greenland halibut (Reinhardtius hippoglossodes), various flatfish, the Atlantic wolffish (Anarhichas lupus), herrings, the arctic cod (Boreogadus saida), and the capelin. Of particular importance are cod and haddock, which constitute 60–90 percent of the total catch. The catches of Sebastes, flatfish, and the Greenland halibut have declined. The total annual fish catch in 1973–74 amounted to 6.4–9.8 million quintals.

The White Sea has more than 60 fish species, of which the herring, the navaga (Eleginus navaga), the Atlantic salmon, and various whitefish are commercially important. The navaga is the principal fish caught. Herring and Atlantic salmon catches have declined in recent years. The total annual fish catch in 1973–74 was 17,000–25,000 quintals.

About 70 fish species inhabit the Baltic Sea, with the following possessing commercial importance: the Baltic sprat (Sprattus sprattus balticus), the Baltic herring (Clupea harengus membras), the Baltic cod (Gadus mohua callarlas), and flatfish, smelts, eels, salmon, and lampreys. Most of the catch consists of the Baltic herring (about 80 percent), the Baltic sprat, and the Baltic cod. Owing to a reduction in the stocks and the intensification of fishing, the catches of Baltic herring and cod have declined. The annual volume of fish caught in the period 1965–76 varied from 1.8 to 3.4 million quintals.

The ichthyofauna of the arctic seas (Kara, Laptev, East Siberian, and Chukchi seas) is quantitatively and qualitatively poor. Of the approximately 60 fish species, only the arctic cisco, the cisco, the navaga, the stone loach, and the muksun are commercially important. The catches are small and restricted to coastal waters.

The ichthyofauna of the Far Eastern seas is rich and varied. Of the approximately 800 fish species, the walleye pollack, the herring, various Pacific salmon, gadids, flatfish, the halibut, Sebastes, the Atlantic mackerel (Scomber scombrus), the Pacific saury (Cololabis saira), and the atka mackerel (Pleurogrammus monopterygius) are of commercial importance. The principal resources of the Far Eastern seas are the salmonids, including the coho salmon (Oncorhynchus kisutch), the chinook salmon, the pink salmon, and the chum salmon, but their stocks and catches have declined everywhere. The catches of the Pacific saury and the Atlantic mackerel fluctuate from year to year, depending on the size of the generations that replenish the commercial stock. The walleye pollack, available in large numbers (15–17 million quintals caught annually in the 1970’s), is a promising fish source. The total annual fish catch in the Far Eastern seas is about 30 million quintals. The main fisheries are in the Bering Sea and the Sea of Okhotsk.

The ichthyofauna of the southern seas is very uniform because of the common origin of the fish. There are about 300 fish species and subspecies in the Aral and Caspian seas, the Sea of Azov, and the Black Sea. Many endemic and relict forms exist here. The Caspian fish stocks have decreased because of the lowering of the sea level and the regulation of the river flow owing to the construction of the hydroelectric power plant cascade. The total fish catch in the Caspian in 1974 was 4.6 million quintals. The sprat is the main commercial fish. The catch of acipenseroids increased in the 1970’s as a result of ameliorative measures, while the stocks and catches of the roach, the European bream, the wild carp, and the pike perch declined sharply.

The ichthyofauna of the Aral Sea is meager. The main commercial fish are the European bream, the pike perch, the wild carp, the barbel, the asp (Aspius aspius), and the sheatfish. The pike perch and the asp make up 65 percent of the catch. Work on the acclimatization of fish and food organisms is needed in order to improve the species composition of the ichthyofauna. The total annual catch in 1973–74 was 162,000–188,000 quintals. The principal commercial fish in the Black Sea are the Black Sea anchovy, the horse mackerel (Trachurus trachurus), and sprats. Flounder, mullets of the genus Mugil, and the red mullet Mullus barbatus constitute an insignificant fraction of the catch. The total annual catch in 1973–74 was 1.1–1.3 million quintals. The principal fish caught in the Sea of Azov are anchovies and tiulkas. Changes in prevailing marine conditions have caused the European bream and pike perch stocks and catches to decrease. The initiation of fish breeding has resulted in the growth of the acipenseroid population. The total annual fish catch in 1973–74 was 1.6–2.0 million quintals.

The USSR has developed and is implementing various measures to ensure the efficient management of the fishing industry (see below: Conservation).

Destructive animals. Among the animals that inflict damage to the economy and injure human health are forest and crop pests, bloodsucking flies, and animals that are sources of diseases of man and beneficial wild and domestic animals.

CROP PESTS. The principal crop pests are insects, as well as mites and ticks, nematodes, terrestrial mollusks, and rodents. Crop pests are subdivided into polyphagous pests (those that injure various crops) and specialized pests (those that feed on a single crop or several related crops). A distinction is made between grain, industrial crop, vegetable, melon, potato, and other types of pests.

The principal polyphagous grain pests are various owlet moths, the European corn borer (Pyrausta nubilasis), wireworms, false wireworms, and locusts. The most destructive specialized pests in the steppe zone are the Hessian fly (Mayetiola destructor), the grain pentatomid Eurygaster integriceps, grain beetles of the genus Anisoplia, Zabrus tenebrioides, Euxora nigricans, and the wheatworm (Anguina tritici), and in the nonchernozem zone, the frit fly (Oscinella frit), the gout fly (Chlorops pumilionis), the stem flea beetle (Chaetocnema hortensis), and the owlet moth Apamea paludis (or Amphipoea fucosa). The polyphagous species are particularly dangerous for corn, for example, the mole cricket Gryllotalpa gryllotalpa, the European corn borer, Agrotis segetum and other gnawing owlet moths, and the cotton bollworm (Heliothis armigera).

Of the industrial crops, the sugar beet is most subjected to injury. Its most dangerous pests are the beet webworm (Lyxostege stricticalis), Agrotis segetum and other gnawing owlet moths, wireworms, beet weevils, and the beet bug (Poeciloscytux cognatus). All the cotton pests in the USSR are polyphagous; they include locusts, cotton aphids, the cotton bollworm, wire-worms, false wireworms, and red spider mites. The most dangerous specialized cotton pests are not found in the USSR owing to the well-developed quarantine service.

Forty species of vegetable and melon pests are particularly dangerous. Vegetables of the family Cruciferae, such as cabbages and turnips, are the most susceptible. They are attacked by the cabbage maggot (Hylemyia brassicae), curculionid wireworms, Ceutorrhynchus pleurostigma, flea beetles, cabbage butterflies, the cabbage cutworm (Barathra brassicae), and the diamondback moth (Plutella xylostella). Potatoes are attacked by more than 60 species of pests, chiefly the Colorado potato beetle (Leptinotarsa decemlineata), which has penetrated into the western part of the USSR, where systematic control measures have been instituted. Wireworms and the Far Eastern 28-spotted ladybug (Epilachna virgintioctomaculata) are also dangerous.

Of the fruit pests, various beetles, butterflies, and aphids are the most dangerous. The most susceptible are apple trees [codling moth (Carpocapsa pomonella)] and pear, plum, and cherry trees, grape vines, and various berries, including strawberry and raspberry. Many pests were brought in from other countries before the organization of the quarantine service in the USSR, including Phylloxera and the San Jose scale (Quadraspidiotus perniciosus). Citrus crops are injured by the citrus whitefly (Dialeurodes citri), the dictyospermum scale (Chrysomphalus dictyospermi), and the armored scale Leucaspis japonica.

The damage inflicted by many pests is decreasing as a result of major contouring of fields, the use of advanced farming techniques, and constant control efforts.

FOREST PESTS. Trees and shrubs in the USSR are attacked by a variety of pests. Extensive insect reproduction is especially frequent in Siberia and the central part of the European USSR. Primary pests (needle- and leaf-gnawing pests) attack healthy trees. Such pests are mostly caterpillars, especially of silkworm moths, and some beetles, hymenopterans, homopterons, and hemipterans. The most dangerous pest of Asiatic coniferous forests is the silkworm moth Dendrolimus sibiricus, which attacks mainly cedar, fir, and larch and about 17 other coniferous species. In the central part of the European USSR, the pine moth Dendrolimus pini, the nun moth (Ocneria monacha), the pine moth Panolis flammea, and the pine looper Bupalus piniarus attack pines and other trees. Other pests include pine-shoot moths and, among the hymenopterans, sawflies of the family Pamphiliidae. The gypsy moth (Porthetria dispar) is a dangerous pest of hardwood trees in the European USSR. Oaks are attacked by the gold-tail moth (Euproctis chrysorrhoea) and the European oak roller moth (Tortrix viridina), birches by sawflies, and aspens, poplars, and willows by the satin moth (Leucoma salicis) and the aspen leaf beetle (Melasoma tremulae). Secondary (trunk) pests, which damage weak or dying trees, include various beetles, carpenter moths, and, of the hymenopterans, horntails. Most live in or under the bark (bark beetles), while some live in the xylem, for example, long-horned beetles (Cerambycidae) and jewel beetles (Buprestidae). Root (soil-inhabiting) pests, such as chafer larvae, wireworms, and false wireworms, are especially dangerous for young trees in natural forests, nurseries, and planted forests.

Fruits and seeds are injured primarily by leaf-roller moth caterpillars, pyralids, and curculionids, as well as by the eastern larch beetle (Dendroctonus simplex) and olethreutid caterpillars.

WILD ANIMALS HARMFUL TO MAN AND DOMESTIC ANIMALS. Wild animals carry, transmit, or cause many diseases (zoonoses). Some bloodsucking arthropods, such as ticks, dipterans, and fleas, are transmitters and reservoirs of diseases. Wild mammals and, less commonly, birds and domestic animals may be carriers (hosts). Helminths and protozoans are causative agents of various diseases. Human beings and domestic animals may serve as hosts. Among the main zoonoses prevalent in the USSR are the plague, encephalitis, leptospirosis, hemorrhagic fevers, tularemia, toxoplasmosis, malaria, and leishmaniasis. Bloodsucking dipteran insects, such as bloodsucking flies and gadflies, are very injurious to the health of human beings and domestic animals.

Bibliography

The USSR spans four geographic belts: the arctic belt, in which the arctic desert zone is located; the subarctic belt, in which the tundra and forest-tundra zones are located; the temperate belt, in which the zones of taiga and mixed and broad-leaved forests are located (these can also be considered subzones of a single forest zone), as well as the forest steppes, steppes, semideserts, and deserts; and the subtropical belt, in which the semidesert zone and the Mediterranean zone of dry-summer forests and shrubs are located (the Mediterranean zone is sometimes considered a subzone within the zone of subtropical forests). Most of the USSR is in the temperate belt.

Zonality is best expressed on the East European Plain and in the Western Siberian Lowland. In Central and Eastern Siberia latitudinal zonality is less marked, primarily owing to the ruggedness of the topography, greater continentality of the climate, and the presence of permafrost. In the Far East it is disrupted by the effect of the seas, with their cold and warm currents, and by the monsoon circulation of air masses and the complex topography. In the mountains latitudinal zonality is further complicated by altitudinal landscape belts, differences in slope exposure, the barrier role of mountain ranges, and various other factors.

Arctic desert zone. The zone of arctic deserts is characterized by a harsh arctic climate; glaciers are widespread on Novaia Zemlia, Franz Josef Land, and Severnaia Zemlia, and the snow cover lasts virtually the entire year. Even in the southern part of the zone, the temperature of the warmest month (July or, in some regions, August) seldom rises above 4°–5°C, although along the southern shore of the Barents Sea it occasionally reaches 8°C. The ground is permanently frozen everywhere. The phenomena of solifluction, ground swelling, and thermokarst are widespread. Vast areas are covered by detritus. The processes of water erosion are virtually nonexistent, since they occur only during the period with above-freezing temperatures, which is very short in the arctic desert zone. Only a thin layer of arctic soils, which are neutral or weakly alkaline and ferruginous, develops on the fine-earth subsoil.

The vegetation is extremely sparse, dominated by mosses, lichens, and algae. Arctic poppies occasionally occur, as well as low-growing willows and dryas (in the southern part). The total reserve of phytomass is less than 5 tons of dry matter per hectare (ha); living, aboveground material predominates over underground material, unlike the structure of the phytomass in the tundra and desert zones of the other geographic belts, where the opposite occurs. The harshness of the climate and low plant productivity are the primary reasons for the scarcity of fauna. Lemmings, arctic foxes, and polar bears are encountered. Reindeer occasionally wander in from the tundra, and there are bird colonies along the rocky shores.

Tundra zone. The tundra zone is unforested and is characterized by excess moisture under conditions of little heat and by extensively developed moss-lichen and dwarf-shrub vegetation. The average July temperature in the southern part of the tundra is 10°–11°C; temperatures higher than 15°C seldom occur. Winters are cold. The average January temperature in the Siberian tundras varies from – 20° to – 34°C; in the European part of the USSR it ranges from – 8° to – 20°C (along the lower course of the Pechora). Strong winds occur frequently, and the relative air humidity is high. Because of the low rate of evaporation of the moisture, the surface is excessively moist despite low precipitation, which varies from 200 to 400 mm a year. Together with the permafrost, which forms a water resistant stratum, this results in significant river runoff during the summer. In the winter, runoff is slight or nonexistent; many small rivers freeze down to the bottom. Shallow lakes of thermokarstic or morainic origin are widespread.

The soils are thin, acid, and poor in bases and humus, with vigorous manifestations of gleying processes. The soil thaws to a depth of 30–40 cm during the summer in the north and to a depth of 60–70 cm in the south. The northern and central parts of the zone are characterized by sparse moss and lichen vegetation and by the presence of bogs; sedge-cottongrass hummocky tundras are found east of the Kolyma River. In the southern part, dwarf-shrub tundra with thickets of dwarf birch alternates with sphagnum and grass-hypnum hummocky bogs. The total reserve of phytomass is 12.5–25 tons/ha.

Among the permanent inhabitants of the tundra are the reindeer, the lemming, the arctic fox, the wolf, the snowy owl, the willow ptarmigan, and the rock ptarmigan. Waterfowl abound on the lakes and rivers in the summer. Mosquitoes and blackflies are abundant.

The tundra has vast pasturelands for domestic reindeer and is a major fur-producing area.

Forest-tundra zone. The forest-tundra zone is a transitional zone between the tundra and the taiga, forming a strip 20–30 to 200 km wide (north to south). The summers here are somewhat warmer than those in the tundra zone, with an average July temperature of 11°–14°C. The sum of the average daily temperatures for the period with temperatures above 10°C is 400°–800°C.

The surface is extremely marshy, with hypnum and sphagnum bogs and deep peat bogs with hummocky surfaces. Thermokarst is widespread, and hydrolaccoliths (high mounds of swollen permafrost) are encountered. There is an intricate combination of peat gley soils typical of the tundras and gley podzolic soils of the northern taiga. The watershed areas are characterized by sparse forests combined with dwarf-shrub tundra. The flat low-lying areas are covered chiefly by tundra vegetation, while the river valleys are covered by taiga-type forests. Birches predominate in the sparse forests of the Kola Peninsula. Spruces predominate east of the peninsula, as far as the Urals, and larches predominate in Siberia. The reserve of phytomass is 25–50 tons/ha.

The fauna of the forest-tundra zone consists of taiga species, such as the elk, the brown bear, the blue hare, and the glutton, as well as of tundra species, such as the lemming, the arctic fox, and the willow ptarmigan. Mosquitoes and blackflies are abundant in the summer.

The forest-tundra zone has reindeer pasturelands.

Taiga zone. The taiga zone is characterized by a cool, relatively humid climate. Coniferous forests predominate, and bogs abound. The summers are warmer than those in the forest tundra and tundra and the winters, in places, are colder. The average July temperature ranges from 13°–14°C in the north to 18°–19°C in the south. The sum of temperatures for the period with temperature above 10°C increases from 800° to 1800°–2000°C from north to south. The average January temperature ranges from – 10°C in Karelia to –43°C on the Central Siberian Plateau. The snow cover, which is 50–80 cm thick, lasts six to eight months. The annual precipitation, which is 400–600 mm, exceeds the rate of evaporation everywhere except in the central parts of Yakutia. Permafrost is widespread in the east. The relief-forming role of water erosion is greater in the taiga zone than in the tundra and forest-tundra zones. Hummocky morainic landscapes have been well preserved in many regions. The runoff is high, measuring 300–500 mm in the north and about 200 mm in the south, and consequently the taiga rivers are high in volume in the summer.

Podzolic soils form beneath the forest canopy. In the north they are supplanted by gley podzolic soils, and in the south, by sod podzolic soils. Frigid taiga soils have developed in the taiga of the Central Siberian Plateau. The natural fertility of taiga soils is low, and consequently they require the application of organic and mineral fertilizers.

Coniferous forests of spruce, larch, pine, and Siberian fir predominate in the taiga. Dark-coniferous forests, primarily spruce forests, are widespread in the western and eastern margins of the taiga zone, where the climate is moderately continental. The central parts of the zone are covered by light-coniferous taiga, primarily larch taiga. The underbrush and herbaceous cover are sparse, although a solid cover of green hypnum mosses and lichens is observed. Dwarf shrubs, such as bilberry and mountain cranberry, are abundant in places. In addition to coniferous forests, small-leaved forests (birch and aspen forests) and mixed forests, usually of secondary origin, often develop. The total reserve of phytomass in the spruce forests of the middle and southern taiga reaches 150–300 tons/ha, with an annual growth of 70–85 quintals/ha. The taiga is extremely boggy, especially in Western Siberia. High-moor (oligotrophic) domed bogs, with significant peat reserves, predominate. Animal life is represented primarily by the brown bear, the elk, the lynx, the squirrel, the Old World flying squirrel, the blue hare, and red-backed mice. The most common birds are the capercaillie, the hazel hen, and various species of woodpeckers, while the most characteristic reptiles are the common viper, various colubrids, and the European common lizard. In many parts of the taiga, mosquitoes and blackflies are abundant in the summer. The taiga is the principal fur-trade region in the USSR (sable, Siberian weasel, squirrel, hare).

The principal resource of the taiga zone is timber. Agriculture is developed in the southern regions, and the meadows and pasturelands are used extensively for dairy and meat stock raising. The gathering of berries (cranberries, mountain cranberries, blueberries, and raspberries), mushrooms, and pine nuts is commercially important.

Mixed-forest zone. The mixed-forest zone is represented in the USSR primarily on the East European Plain and in the Far East. Within the East European Plain it is characterized by a comparatively humid climate and by dark-coniferous-broad-leaved forests growing on sod podzolic soils in the watershed areas. Summers are cool, with an average July temperature of 17°–18°C. The sum of temperatures for the period with temperatures above 10°C is 1800–2200°C. Winters are relatively mild, with an average January temperature of –3° to –4°C in the west and about – 12°C near the city of Gorky. As a result of frequent thaws, the snow cover in the west is shallow, usually less than 30 cm, and unstable; in the east, it reaches 50 cm and lasts up to five months. The annual precipitation is 500–800 mm, which somewhat exceeds the evaporation rate. The runoff reaches 150–300 mm. The river network is dense, and the rivers have a high water volume. Shrub-invaded spruce and oak forests on sod podzolic soils usually grow on the hills. The sandy plains are occupied by pine forests, while bogs develop in the basins and lowlands with limited drainage. The total reserve of phytomass in the forests of the mixed-forest zone reaches 300–400 tons/ha.

The flora and fauna have been enriched by species characteristic of Western Europe. The hornbeam occurs in the oak forests west of Vilnius and Minsk. Yew, ivy, and beech grow on the western shore of the Baltic Sea. The fauna is characterized by the brown bear, the wolf, the fox, and the elk, which exist side by side with the roe deer, the pine marten, the European mink, the tree dormouse, and the weasel Putorius putorius.

Most of the forests have been cut, and only about 30 percent of the region is forested today. The relative proportion of spruce and oak has decreased, while the proportion of birch and aspen has risen. The zone is densely populated, and about one-third of its area is under cultivation. Climatic conditions are favorable for growing potatoes, vegetables, flax, grains, forage grasses, and, in some places, sugar beets.

In the Far East mixed forests occupy the plains and low foothills of the Central and, in part, Lower Amur regions and the southern part of Primor’e Krai. The principal natural features here are the result of the monsoon climate. In the winter, when cold winds from the continent prevail, consistent freezing weather occurs, with an average January temperature of –28°C in the north and –16° to – 18°C in the south. As a result, the soil freezes to a great depth and the growing season begins late in the spring. Monsoon rains, which result in floods, are frequent during the summer, which has an average July temperature of 21°–22°C. Many regions are boggy. The sum of temperatures for the period with temperatures above 10°C reaches 2800°C.

The forests are characterized by a diversity of tree and shrub species, by multiple strata, and by an abundance of lianas and epiphytic mosses. The forests, which grow on brown forest soils, are composed of Korean pine, Mongolian oak, Amur linden, fir, and the birch Betula costata. Meadow vegetation, which in some places is steppe-like, and meadow chernozem soils predominate in the Zeia-Bureia and Khanka lowlands. The fauna is represented by both taiga species and southern species of East Asian and Indo-Malayan origin. Squirrels and chipmunks are common; other animals include the Ussuri tiger, the Asiatic black bear, the Japanese deer, the yellow-throated marten, the wild boar, and the racoon dog.

Most of the plains have been brought into agricultural use.

Broad-leaved forest zone. The broad-leaved forest zone is characterized by a mild, fairly humid climate and by extensive oak forests on sod podzolic and gray forest soils. It encompasses the East European Plain, gradually tapering in the east and forming a narrow strip between the mixed-forest zone in the north and the forest-steppe zone in the south. The average January temperature varies from –5° to –7°C; the average July temperature is 19°–20°C. The sum of temperatures for the period with temperatures above 10°C is 2200°–2500°C. The zone is characterized by optimal moisturization: the annual precipitation, which totals 600–700 mm, is close to the evaporation rate. Loesses and loesslike loams are common soil-forming rocks. When subjected to water erosion, they facilitate the formation of gulleys on plowed slopes.

Forests of oak are characteristic, intermixed with ash, linden, maple, elm, and other broad-leaved species, with a dense underbrush (hazelnut, staff tree, honeysuckle) and a well-developed herbaceous cover. Steppe-like pine forests occur in the sandy lowlands and on the river terraces. Bogs are few; high-moor and transitional bogs, characteristic of the northern regions of the country, are supplanted by low-moor bogs. Many steppe species occur among the grasses and wildlife. In the southern part of the zone, pockets of podzolized and leached chernozems are found among the gray forest soils.

The zone is densely populated, and a significant share has been brought under cultivation.

Forest-steppe zone. The forest-steppe zone, with forests on gray forest soils alternating with forb steppes on chernozems, stretches in a continuous band from the Carpathian Mountains to the Altai Mountains. The average July temperature is 20°–22°C. The sum of the average daily temperatures for the period with temperatures higher than 10°C is 2600°–2800°C in the southwest and 1800°–2000°C in the east. The average January temperature ranges from –5° in the east to –20°C in the west. The snow cover is unstable in the west but lasts more than five months in the east, where it reaches a depth of 30–50 cm. The annual precipitation is 500–600 mm in the west and 300–400 mm in the east, which is just slightly less than the rate of evaporation. Moisturization is close to optimal but does not occur evenly throughout the year; summer precipitation usually takes the form of heavy rains. Compared to the runoff in the forest zone, the runoff in the forest-steppe zone is low, and the spring high stage on the rivers is more turbulent. The topography, characterized by asymmetric river valleys and numerous gulleys and ravines, was carved out by erosion processes. Small, shallow depressions, formed as a result of undermining and subsidence, are common in the level areas between the rivers.

The forest steppe of Western Siberia, which is not as heavily dissected by gulleys and ravines, has numerous lakes. Oak forests grow on the East European Plain, birch-aspen groves in Western Siberia, and birch-pine-larch forests in Central Siberia. The oak forests are characterized by the greatest biological productivity in the temperate latitudes. The phytomass reserve is 400–500 tons/-ha, with an annual growth of up to 90 quintals/ha. Pine forests occur on the sandy soils in the river valleys. The steppes, which today are almost entirely under cultivation, were once covered primarily by forbs. Steppe areas have survived primarily in the preserves. The alkali and typical chernozems that formed under the forb steppes are distinguished by a high humus content, great thickness, and fine-grained texture. They are among the most fertile soils in the world.

The forest-steppe fauna is characterized by an intricate mixture of forest and steppe species. The elk, the squirrel, and the pine marten live side by side with susliks, marmots, the jerboa Allactaga major, and mouselike rodents.

The forest steppe is one of the most developed natural regions of the USSR; 70–80 percent of the land in the west has been brought under cultivation.

Steppe zone. The steppe zone is characterized by a temperate continental climate. The natural vegetation is dominated by grassy steppes on chernozem and dark chestnut soils. Most of the steppe zone, which extends from the western boundary of the USSR to the Altai Mountains, is under cultivation. In the east, there are distinct areas of steppe landscapes, primarily in the intermontane basins. The average July temperature is 22°–23.5°C. The sum of the average daily temperatures for the period with temperatures above 10°C is 2800°–3400°C in the west and 2000°–2600°C in the east. The average January temperature ranges from –2°C along the western borders of the USSR to – 20°C in the eastern part of the zone; in the steppes of Transbaikalia it drops to as low as – 30°C. In the steppes of the Ukraine the snow cover usually does not exceed 10–20 cm in thickness and lasts one to two months; in the Transural Region the snow cover is up to 30 cm thick and lasts about five months. The annual precipitation is 250–450 mm; it is considerably less than the rate of evaporation. An unstable supply of moisture is typical of the steppes. Droughts occur periodically, and dry winds are observed, sometimes accompanied by dust storms. The rivers have little water. Loess and loess-like loam soils are widespread. The zone has rill and gully erosion topography, with numerous ravines on the slopes; there are many sinks in the interfluvial areas and occasional hills. The common and southern chernozems that have developed in the steppes, as well as the dark chestnut soils, are not as rich in humus and are not as thick as the chernozems of the forest-steppe zone. Solonetzes occur in some areas. In some years there is considerable wind erosion.

Cultivated landscapes predominate in the steppe zone, which is intensively farmed. The surviving areas of natural vegetation are primarily grassy steppes, with feather grass, fescue grass, wheat-grass, and Koeleria, as well as representatives of the genus Cleistogenes (in the steppes of Transbaikalia.). Thickets of steppe shrubs are found on the East European Plain and in the foothills of the Urals and Altai Mountains (matrimony vine, blackthorn, cherry, Russian almond, spirea).

The fauna is characterized by numerous rodents that live in dens, and some are major agricultural pests. Typical animals include the weasel Putorius eversmanni, the corsac fox, susliks, jerboas, pikas, lemmings, and red-backed mice. Common birds inelude the great bustard, the little bustard, larks, the Hungarian partridge, the steppe eagle, and the pallid harrier.

The forest steppe and the steppe constitute the principal grain-growing regions of the USSR. Irrigation, snow retention techniques, and the planting of shelterbelts are important land-improvement techniques.

Semidesert zone. The semidesert zone is characterized by a dry, sharply continental climate, as well as by the predominance of sparse wormwood grassy steppes on light chestnut soils in the watershed areas. Located south of the steppe zone, it stretches in the form of a band from approximately the Ergeni Upland to the Zaisan Depression. There is an area of subtropical semidesert in the Kura-Araks Lowland south of the Greater Caucasus. The average July temperature is 23°–25°C. The sum of the average daily temperatures for the period with temperatures above 10°C is 3200°–3400°C in the west and 2400°–2800°C in the east. The average January temperature drops from west to east from –4° to – 16°C. The depth of the snow cover decreases from west to east from 30 to 10 cm, and its duration is shorter. The annual precipitation is 150–250 mm; it is three to four times less than the rate of evaporation. Runoff is negligible; the rivers are primarily intermittent. Groundwater is often salinized.

The semidesert zone is characterized by light chestnut soils that are poor in humus and exhibit solonetz characteristics. Solonetzes are widespread; meadow chestnut soils occur in the sinks and estuaries. Sod has not developed in all places. Caespitose grasses and low-growing subshrubs (wormwood, vitex, pyrethrum) alternate with ephemerals and ephemeroids. The reserves of phytomass are 5–12.5 tons/ha.

Rodents abound, including susliks, lemmings, jerboas, and red-backed mice. Larger animals include the saiga, the weasel Putorius eversmanni, and the corsac. The bird population is diverse. Insects are numerous, including locusts.

The semidesert zone is a zone of selective irrigated farming. Pasturelands occupy large areas.

Desert zone of the temperate belt. The desert zone of the temperate belt is characterized by an extremely arid, sharply continental climate and by sparse vegetation consisting of low-growing sub-shrubs on brown desert-steppe and gray-brown soils. It encompasses the Caspian Lowland, Kazakhstan, and Middle Asia, stretching south to approximately 40° N lat. The average July temperature is 25°–29°C. The sum of the average daily temperatures for the period with temperatures above 10°C is 3200°–5000°C. Winters are cold, with an average January temperature of about – 12°C in the north and about 0° in the south. The snow cover is shallow (about 10 cm) in the north and lasts about three months; in the southwest it lasts less than one month. This makes it possible to use the desert as winter pasture. The annual precipitation is usually less than 200 mm, and the evaporation rate is 800–1,400 mm. There is virtually no runoff in the deserts; the rivers usually begin in the distant mountains and within the desert zone are intermittent. Physical weathering and wind action are extremely intensive. Sand ridges and barchans, undrained basins, inselbergs, and dry river channels are typical relief forms. Takyrs, solonchaks, and sandy areas with an undeveloped soil cover occupy large areas.

The acute shortage of moisture and the frequent salinization of soils result in sparse vegetation, in which perennial xerophilous low-growing subshrubs predominate. Shrubs grow on the sand, and ephemerals and ephemeroids are found in some places. Wormwood-saltwort communities are typical of the clay and loam soils. The phytomass reserve is negligible (2.5–5 tons/ha); the underground part far exceeds the aboveground part of the phytomass. The phytomass reserve increases to 25–50 tons/ha in saxaul thickets.

Typical animals include the goitered gazelle, jerboas, the great gerbil, the wildcat Felis margarita, the manul, the cape hare, and the tortoise Testudo horsfieldi. There are many snakes, including poisonous ones, and numerous lizards.

Rice and cotton are raised on irrigated lands; there are orchards and vineyards in the oases. Significant areas are used as pastures.

Desert zone of the subtropical belt. The desert zone of the subtropical belt, unlike the desert zone of the temperate zone, is characterized by relatively warm winters, without a stable snow cover. It encompasses the plains of Middle Asia south of 40° N lat. The average July temperature is 30°–32°C. The average January temperature is close to 0°C, and plant growth does not ordinarily stop in the winter. The sum of temperatures for the period with temperatures above 10°C is 5000°–5600°C. Ephemerals and ephemeroids are widespread. The phytomass reserve in ephemeral-dwarf-subshrub deserts is 5–12.5 tons/ha. Animal species of southern origin, such as the striped hyena, Brandt’s hedgehog, the Levantine viper, and the cobra, are often encountered. Typical animals of the ephemeral deserts are the tortoise Testudo horsfieldi and the suslik Citellus fulvus, while typical animals of the sandy deserts include the sand snake Eryx miliaris, the snake Taphrometroron lineolatus, the saw-scaled viper, and the desert monitor.

Heat-loving crops are raised in the oases; in some places, two harvests a year are grown. The principal economic problem is water supply for irrigation and for watering pastures.

Mediterranean zone of the subtropical belt. The southern coast of the Crimea and the western part of Transcaucasia occupy the eastern margins of the Mediterranean zone of Eurasia. Along the southern coast of the Crimea and along the Black Sea coast of the Caucasus north of the city of Tuapse, a moderately hot, dry summer alternates with a comparatively warm, humid winter; near Yalta, the average January temperature is about 3°C, the average July temperature is 24°C, and the annual precipitation is about 600 mm. Xerophytic shrubs and forests of oak and pine on cinnamon soils are typical. The Colchis Lowlands and the Lenkoran’ Lowland, which lie in the semihumid subtropics, have a more humid climate owing to their location at the foot of coastal mountain ranges. The annual precipitation is about 1,500 mm in the Colchis Lowlands and slightly less in the Lenkoran’ Lowland. In the southern part of the Colchis Lowlands, the average January temperature is 6°–7°C. Dense broad-leaved forests, overgrown with lianas and occasionally interspersed with evergreen species, are widespread. They are composed of oak, hornbeam, beech, chestnut, and alder; evergreens include the ponticum rhododendron, the box tree, and the cherry laurel. The main soils are red earths and yellow earths.

The Lenkoran’ Lowland is characterized by an abundance of unique animals, including the porcupine, the leopard, and the jungle cat; flamingos are encountered along the Caspian Sea.

Subtropical fruits and grapes are grown in the Mediterranean zone. Tea and citrus fruits are cultivated in the Colchis and Lenkoran’ Lowlands.

Altitudinal zonality. Altitudinal (vertical) zonality is determined primarily by the elevation of the mountains and by their position within the natural zones and proximity to the oceans. It differs fundamentally from latitudinal zonality, since sharp changes in the entire spectrum of natural conditions occur in the mountains in a relatively small area. The exposure of the slopes and the position of the slopes relative to the prevailing transfer of air masses play a major role in altitudinal zonality.

The mountains of the southern part of the USSR typically have more altitudinal zones on the more humid macroslopes. Landscapes similar to those of the adjacent plains usually occur in the lower strata. At higher elevations, the entire aggregate of natural conditions often changes as air temperature decreases and moisture increases. For example, the western slopes of the Urals, moistened by the prevailing westerly winds from the Atlantic, are characterized by a more complex spectrum of altitudinal zonality than the eastern slopes. Because of the significant meridional extent of the Urals, the spectrum of altitudinal zonality changes greatly from north to south. In the Far North, to approximately 66° N lat., only the belt of mountain tundra is developed. Farther south, to 59° N lat. the lower belt is represented by mountain taiga and the upper belt by elfin woodland of spruce and birch, combined with mountain tundra.

In the Central Urals and in some parts of the Southern Urals, the taiga forests in the lower belt are supplanted by mixed forests, with linden, maple, and oak; the mountain tundra belt is found only at the summits. Forest steppes, mountain steppes, and, in some places, semideserts are found in the southernmost parts of the Urals, at the base of the mountains and on the lower slopes. In the mountains of Eastern Siberia the lower belt is usually represented by mountain taiga, while mountain tundra occurs at higher elevations. In the mountains of the Baikal Region and Transbaikalia, forest steppes and steppes are encountered within the intermontane basins. In the mountains of the Sikhote-Alin’, Pacific monsoons and cold marine currents are responsible for the more complex altitudinal zonality on the windward eastern and southeastern slopes.

On the northern slopes of the Caucasus the steppe landscapes of the lower belt are followed by a belt of broad-leaved and coniferous forests, which is supplanted first by a subalpine belt of elfin woodlands and tall-herb meadows and then by an alpine belt of low-herb meadows and rock vegetation. At the top lies the nival zone of snow and ice. The belt of broad-leaved and coniferous forests is often missing on the southern slopes. In the mountains of Middle Asia, a belt of mountain deserts and semideserts is found at the bottom of the sequence and, because of the great continentality and aridity of the climate, the belt of mountain forests is relatively insignificant, with forests usually confined to the northern slopes. At higher elevations are meadows, cliffs, névés, and glaciers.

There are several schemes for the physicogeographical regionalization of the country. This section uses a scheme in which the land area of the USSR, with certain adjacent regions of non-Soviet Eurasia, encompasses 19 physicogeographical countries. In the process of regionalization, all the natural conditions of a particular region were taken into account, as well as the zonal and nonzonal factors responsible for the formation of the landscape.

Arctic islands. The arctic islands are the only part of the USSR entirely surrounded by ocean. They include the archipelagoes and individual islands of the Arctic Ocean. Among them are flat islands, such as the Novosibirskie Islands, and mountainous islands, for example, Novaia Zemlia and Vrangel’ Island. Glacial landscapes are characteristic, as are arctic deserts, which are virtually devoid of vegetation and, in some places, arctic tundras.

Fennoscandia. Most of Fennoscandia is located in Western Europe, except the Kola Peninsula and Karelia, which are located in the USSR. The Baltic Shield constitutes the principal element of the surface. During the ice ages of the Anthropogene, Fennoscandia was a region of glacial ablation. The hilly plains and low mountains (Khibiny) are interspersed with lake basins. The lakes are usually interconnected by short, rushing rivers. The climate is cool and humid. The surface is abundantly moistened and often boggy. Northern taiga forest vegetation predominates. Pine forests are most common on the rocky hills, while ridges and spruce forests are found in the lowlands. Birch forest tundra and tundra occur on the northern edge of the Kola Peninsula.

East European (Russian) Plain. Most of the East European Plain coincides with the Russian Platform of the Eastern European Platform; in the south it also includes the Crimean steppe and the western and central parts of Ciscaucasia. During the ice ages of the Anthropogene, the northern part of the plain was covered by a continental ice sheet. Morainic and hill-ridge topography has remained, with numerous depressions that are often occupied by lakes and bogs. The nonglacial regions are characterized by broad terraced river valleys dissected by the ravines and gullies of the interfluvial areas and, in the south, by flat aggradational plains with marine deposits.

Loesses are well developed. The river network is heavily branched. The climate is moderately continental and is quite humid in the northwest and west and somewhat dry in the southeast, with a marked increase in temperature toward the south.

The latitudinal and sublatitudinal zonality of landscapes is clearly expressed. The tundra and forest tundra stretch along the Arctic Ocean. More than one-half of the East European Plain is occupied by taiga and mixed and broad-leaved forests. Timber is an important natural resource; significant areas, especially in the south, have been brought into agricultural use. Further south stretch the forest-steppe zone, the steppe zone, and, in a small part of the southeast, the semidesert zone. Most of the areas of the forest-steppe and steppe zones with chernozems and, in the south, with dark chestnut soils are under cultivation.

Urals. The Urals are a system of folded and block-folded mountain ranges, stretching almost 2,000 km in a meridional direction and consisting primarily of medium-elevation mountains. The greatest elevations occur in the north, in the Polar Urals, where small glaciers occur. The clearly marked altitudinal zonality of landscapes is manifested in a setting of latitudinal zonality. In the lower elevations of mountains the landscape sequence from north to south is tundra, taiga, mixed forest, forest steppe, and steppe. Small areas are occupied by mountain-forest landscapes; mountain tundra and bald-mountain landscapes are widespread in the north.

Ukrainian Carpathians and Transcarpathian Lowland. The Ukrainian Carpathians and the Transcarpathian Lowland are part of the Alpine-Carpathian country, most of which lies outside the USSR. The mountains are primarily of medium elevation, with flattened summits. Oak and beech forests predominate in the lower elevations. At higher elevations they are replaced by mixed and coniferous forests, which above 1,500 m are replaced by mountain, primarily subalpine, meadows. The Transcarpathian Lowland forms the northeastern margin of the alluvial Middle Danubian Plain. A significant portion of the area has been brought under cultivation. There are small areas of oak-hornbeam forests.

Crimean-Caucasian mountain country. The Crimean-Caucasian mountain country encompasses the Crimean Mountains, the Greater Caucasus, the Lesser Caucasus, and the Talysh Mountains, as well as the Lenkoran’ Lowland, which lies at their foot, and the intermontane basins separating the Greater and Lesser Caucasus—the Rioni Basin with the Colchis Lowlands and the Kura Basin with the Kura-Araks Lowland. The entire region is seismic. Mountain-forest landscapes predominate in the Crimean Mountains, and denuded, partially turf-covered karst landscapes find classical expression on the summits of the Iaila Ridge. The natural features of the southern coast of the Crimea appear to be Mediterranean. Mountain-forest landscapes (with coniferous-broad-leaved forests) and high-mountain meadow (subalpine and alpine) landscapes predominate in the Greater Caucasus, whose sharp, jagged peaks are covered with permanent snow and ice; the meltwater from the snow and ice plays a significant part in feeding the rivers. The western part of the mountains receives considerable precipitation, up to 3,200 mm a year on the southwestern slopes, the highest annual precipitation in the USSR. The landscapes of the eastern part form under drier, more continental, conditions. Karst topography has developed on the foreranges, especially in the southwest. Mountain-steppe and mountain-meadow landscapes predominate in the Lesser Caucasus. Meadow steppes are developed in the crest zone of the Talysh Mountain, while the slopes are covered by forests. The Lenkoran’ and Colchis lowlands and the surrounding low mountains lie in the humid and semihumid subtropics, and the predominant landscapes are broad-leaved forests and bogs. The Kura-Araks Lowland is an area of subtropical semideserts.

Armenian Highland and the Kopetdag. The Armenian Highland and the Kopetdag are part of the Southwest Asian Highlands, which are chiefly in non-Soviet Asia. Only the northeastern margin of the Armenian Highland extends into the USSR. Volcanic mountain-steppe and mountain-meadow landscapes predominate. The flat steppe surfaces of the lava plateaus are often cultivated, as are the plains with mountain chernozems. The Kopetdag is part of the mountainous northern margin of the Iranian Highland. Subtropical semidesert and mountain-steppe landscapes predominate, with highland xerophytes and juniper elfin woodlands occurring in the upper zone; broad-leaved gallery forests are found in the mountain valleys in the west. Both the Armenian Highland and the Kopetdag are seismic regions.

Middle Asian mountain country. The Middle Asian mountain country includes the mountain systems of southeastern and eastern Kazakhstan and Middle Asia: the Saur Range, the Tarbagatai Range, the Dzungarian Alatau, the Tien-Shan (without the highest eastern and southeastern parts), and the Gissar-Alai system. It has undergone extensive neotectonic uplifts, and seismicity is associated with neotectonic movements along faults. Semidesert landscapes predominate in the foothills, while mountainsteppe landscapes predominate in the low and middle-elevation mountains. Subtropical landscapes are found at the foot of the Gissar-Alai. Shrub thickets and forest stands occur on the more humid slopes. There are walnut forests in the south and southwest and aspen and apple forests in the north. Coniferous forests consisting of Schrenk’s spruce and juniper occur at higher elevations. Mountain meadows and meadow steppes occur in the highest mountains. Glaciation is well developed, with valley, cirque, hanging, and, in some regions, flat-summit glaciers.

Syrt region of the Tien-Shan and the Pamirs. The syrt region of the Tien-Shan and the Pamirs includes the highest mountains in the USSR, which are part of the natural countries of the highlands of Central Asia, most of which are outside the USSR. The area is seismic and characterized by greatly uplifted flat valleys and basins (known locally as syrty). The landscapes are formed under the conditions of a sharply continental climate, particularly in the enclosed intermontane basins. The climate of the mountains is harsh owing to the great absolute elevations; in some parts of the syrt plains, the climate is arid.

The highest mountain uplifts accessible to the westerly streams of air that carry moisture have thick glaciation, with enormous dendritic valley glaciers, for example, the Inyl’chek and Fedchenko glaciers. There are also small valley, cirque, hanging, and flat-summit glaciers. Landscapes characteristic of cold deserts and semideserts and mountain stony tundras have formed in the syrty of the Tien-Shan and in the eastern Pamirs. Permafrost covers significant areas. High-mountain steppes and meadow steppes are widespread in the more humid areas; forested areas also occur.

Middle Asian plains country. The Middle Asian plains country includes the deserts and semideserts of the Turan and Caspian lowlands and the southern part of the Balkhash Region. Its principal part corresponds to the Turan Plate. A region of internal drainage, it receives many rivers that originate in the mountains of Middle Asia. Plains predominate in the topography. Ridged and hilly sands cover significant areas. The climate is sharply continental and arid, with hot summers. The northern part lies in the temperate belt, while the southern part lies in the subtropical belt and is characterized by relatively mild winters. Semideserts and deserts, primarily clay and sandy deserts in the north and clay and loess deserts in the south, are widespread. There are patches of stony desert and solonchaks. The Middle Asian plains country is characterized by psammophytic and wormwood-saltwort vegetation, with numerous ephemerals in the south.

Turgai Plateau and central Kazakhstan. The region of the Turgai Plateau and central Kazakhstan occupies an intermediate position between the plains of Middle Asia and Western Siberia. Its western part, where flat plains predominate, corresponds to the Turgai Trough. The Kazakh Melkosopochnik occupies the central and eastern parts. Plains with hills and gentle ridges, composed of parent rock, predominate. Rugged residual massifs occur. From north to south the latitudinal steppe zone gives way to the semidesert zone.

Western Siberian Lowland. The Western Siberian Lowland is an aggradational plain, whose tectonic foundation is the Western Siberian Plate. It is very flat and poorly drained, and several more dissected ridges up to 300 m in elevation are observed on its surface. The northern part lies in the permafrost zone, which is conducive to the formation of bogs. Various zones are traced from north to south in Western Siberia, namely, the tundra, forest-tundra, forest (with coniferous and small-leaved forest), foreststeppe (with birch-aspen forests), and steppe zones. There are solonchaks and solonetzes in the forest-steppe and steppe zones of the south. Salt lakes with no outlets occur.

Central Siberia. Most of Central Siberia is occupied by the Central Siberian Plateau, which is bounded by the Central Yakut Plain on the east and the North Siberian Lowland and the Taimyr Peninsula with the Byrranga Mountains on the north. Igneous rocks (known as Siberian traps) are widespread. The Central Siberian Plateau is most uplifted in the northwest (the Putorana Plateau) but has a relatively level surface.

The climate of Central Siberia is sharply continental, and permafrost is ubiquitous. The rivers have a high water volume. Arctic tundras predominate on the Taimyr Peninsula, with arctic deserts occurring occasionally in the hills and mountains. The North Siberian Lowland is dominated by tundra, which is supplanted in the south by forest tundra and elfin woodlands. In the northern half of the Central Siberian Plateau there are mountain tundra, bald-mountain, and larch elfin woodland landscapes. To the south stretch vast taiga forests, with pockets of forest steppe in the southernmost parts. The latitudinal zonality of landscapes is modified by the influence of altitudinal zonality and permafrost. Small areas of meadow and solonetz steppes occur amid larch taiga on the plains of Central Yakutia.

Altai-Satan mountain country. The Altai-Saian mountain country includes the Altai and Saian mountain systems, the Salair Ridge, the Kuznetskii Alatau, and the mountains of Tuva. Planation surfaces and deep intermontane basins are characteristic. The climate is sharply continental. In the west, which has more moisture, dark-coniferous forests predominate, which at higher elevations give way to cedar elfin woodlands and alpine meadows. There are steppes and semideserts in the intermontane basins and at the foot of the ranges on the south and east. At higher elevations they are replaced by forests of larch and cedar. Still higher are bald-mountain and mountain-tundra landscapes. Areas of permafrost occur, and glaciers have developed in the high mountains.

Baikal Region and Transbaikalia. The Baikal Region and Transbaikalia are characterized by high ranges, separated by longitudinal troughs and alternating with medium-elevation mountains and plateaus, such as the Aldan Plateau. The summits of the high mountains are primarily flat; some are jagged. The climate is sharply continental; it is dry in the basins and more humid and cooler in the mountains. Permafrost is widespread. Forest-steppe landscapes and, in the south, steppe landscapes occur in the basins, as well as pine forests and meadows. Coniferous forests, both larch and cedar-fir taiga, grow on the mountain slopes. The mountain summits are bald.

Dahurian country. The Dahurian (Daur) country lies primarily in Mongolia and China, with only a small part included within the boundaries of the USSR. It is dominated by vast rolling plains, with isolated flat-topped mountain ranges rising to 1,000–1,500 m. The climate is sharply continental; areas of permafrost occasionally occur. Steppe and forest-steppe landscapes predominate; solonchaks and solonchak meadows are found in some places, such as the Borzia Steppe. Pine forests occur in sandy areas, while steppe-like larch forests are found on the northern slopes of the higher ranges.

Northeastern Siberia. Most of northeastern Siberia is mountainous. Framed on the west by the arc-shaped Verkhoiansk Range, northeastern Siberia is occupied by plateaus, for example, the Yukaghir Plateau, and by marshy lowlands with numerous lakes in the north, for example, the Iana-Indigirka and Kolyma lowlands. There are glaciers high in the mountains, for example, in the Buordakh Massif of the Cherskii Range and in the Suntar-Khaiata Range; permafrost is widespread. The climate is harsh and sharply continental, especially in the Verkhoiansk and Oimiakon basins, where the coldest places in the northern hemisphere are located. Larch elfin woodlands, mountain-tundra, and bald-mountain landscapes predominate, with tundra occurring in the north.

North Pacific country. The north Pacific country includes the Chukchi Peninsula, the Anadyr’ Plateau, the Anadyr’ Lowland, the Koriak Highland, the Kamchatka Peninsula, and the Komandorskie and Kuril islands. It is characterized by mountain ranges with sharp peaks, volcanic plateaus with volcanic cones, and medium-elevation massifs. There are numerous active volcanoes, and earthquakes occur frequently in the southern half. Permafrost is found in the northern and central parts of the region. The climate is cold marine and subject to the long-range effects of monsoons. Summers are cloudy and rainy; fogs, are frequent. Tundras stretch from the Chuckchi Peninsula far to the south, where taiga landscapes are encountered. Mixed forests with lianas and bamboos occur in the southern part of the Kuril Islands. Meadows and bogs are found in the coastal lowlands. The mountains have sparse forests of Erman’s birch, thickets of dwarf stone pine, and alder groves. Mountain tundras and bald-mountain landscapes are found on the peaks.

Amur-Sakhalin country. The Amur-Sakhalin country includes the area along the Amur, with its mountains and lowlands, Primor’e Krai (Sikhote-Alin’ Range and the plains to the west), and the island of Sakhalin. There is significant seismic activity in the east. The climate is monsoonal, with warm, rainy summers and cold winters. Taiga landscapes with larch forests and, in the east, dark-coniferous forests predominate. Bogs with stunted larch forests, called mari, cover large areas. Thickets of dwarf stone pine and bald-mountain landscapes occur on the mountain summits. Unique Far Eastern coniferous-broad-leaved and broadleaved forests are found at lower elevations in the Sikhote-Alin’ Mountains, in the southern part of the Amur Region, and in the southwestern part of Sakhalin; on the plains, most of the forests no longer exist.

Conservation in the USSR includes a system of state and public measures (biotechnical, technological, economic, and administrative and legal measures) that makes it possible to maintain the productivity and beauty of nature and to preserve the natural conditions necessary to supply the national economy with raw materials and energy. Conservation is also essential in helping provide man with recreational enjoyment and maintain human health. It helps preserve typical natural complexes and interesting features of living and nonliving nature. Conservation in the USSR is based on the socialist ownership of land and its resources. Conservation is a constituent part of the system for effecting the rational use of natural resources.

Legal aspects. The objectives and forms of conservation have differed considerably at various stages of society’s development, since the relative assessments of the value of natural conditions and resources have changed and the human threat to nature has grown with the evolution of the technology and economics of exploiting nature. The desire to protect nature existed in the popular consciousness long before the appearance of administrative and legal forms of conservation. The first legal restrictions on the use of natural resources were imposed in Kievan Rus’ in the 11th century. The Russkaia Pravda of Iaroslav the Wise speaks of limiting the hunting of wild animals and birds. In the 14th and 15th centuries forest clearings in the central part of the East European (Russian) Plain were important for the defense of the country and consequently were accorded special protection by the state. The codes of laws of the Grand Duchy of Lithuania of the 16th century included logging, fishing, and hunting quotas. In the midnth century, 67 ukases on hunting were issued in Russia, the first preserves were created (the Kuntsevo and Sem’ Ostrovov preserves), and the sable-rich areas along numerous rivers were placed under protection. In 1683 the cutting of trees was also prohibited in the sable-rich areas of Siberia. Legislation protecting nature increased significantly under Peter the Great, who also organized a forestry service and placed water-conservation forests and certain tree species under protection. With the growing threat of the deforestation of the European part of Russia, a statute was introduced in 1888 on the conservation and protection of forests. The statute and the subsequent law on hunting (1892) reflected the desire to regulate the corresponding industries, whose intensive development as a result of accelerated technological progress was beginning to threaten the preservation and regenerative capabilities of nature.

In the early 20th century the Russian scientific community began to promote conservation. The Conservation Commission was formed in 1909 as part of the Russian Geographic Society (in 1912 it was renamed the Permanent Conservation Commission), and the first Russian law on preserves was passed in 1916 on its initiative. However, these legislative measures proved to be inadequate, and the uncontrolled development of the capitalist economy resulted in considerable damage, sometimes irreversible, to the environment in Russia, especially in the European part.

The victory of the October Revolution of 1917 marked the beginning of a qualitatively new stage in conservation. More than 200 decrees pertaining to conservation and general problems of the use of nature were issued in the first five years of the Soviet state’s existence. Most were developed in accordance with V. I. Lenin’s instructions, and some even bear his signature. The fundamental legislative act was the Decree on Land, adopted by the Second All-Russian Congress of Soviets in 1917, which abolished the private ownership of land; the decree created fundamentally new opportunities for organizing conservation efforts. It was soon followed by several other decrees, including the decree of the All-Russian Central Executive Committee On Forests (May 27, 1918) and the decree of the Council of People’s Commissars of the RSFSR On State Therapeutic Localities (Apr. 4,1919), all of which ensured the rational use of particular natural resources. These were subsequently supplemented by the decree of the Council of People’s Commissars of the RSFSR On the Preservation of Monuments of Nature, Gardens, and Parks (Sept. 16, 1921), according to which “natural regions of considerable size noted for their remarkable features are declared to be preserves and national parks.” The People’s Commissariat for Education was placed in charge of conservation, since it was a department with no interest in the exploitation of natural resources.

The foregoing documents established a unified system of principles for the socialist use of natural resources, which served as the basis for all future conservation legislation. Extensive departmental statutes and instructions on water, forest, and soil conservation, on sanitation measures, on hunting, and the like were an important part of the system. The interdepartmental State Committee for Conservation was formed to coordinate the activities of various people’s commissariats and departments pertaining to the exploitation of natural conditions and resources. Local interdepartmental commissions were set up under the provincial executive committees of the soviets. The State Committee for Conservation was placed in charge of all conservation activities, recommending ways of preventing the overuse of natural resources (that is, excessive logging, fishing, fur procurement, and the like); it also identified objects necessitating protection.

The All-Russian Society for the Conservation of Nature was organized in 1924, and similar societies were later founded in the other Union republics. The First All-Union Congress on Conservation was held in 1933. Its resolutions, which were primarily concerned with the resources of living nature, emphasized that conservation should also seek to prevent the destructive and mismanaged use of natural resources and to promote the regeneration of various resources.

In conformity with the tasks of the national economy, a decree of the All-Russian Central Executive Committee and the Council of People’s Commissars of the USSR of June 20, 1930, reorganized the State Committee for Conservation into the Interdepartmental State Committee for Promoting the Development and Protection of Natural Resources under the People’s Commissariat for Education of the RSFSR. The focus of the new committee’s activities shifted to the rational use and regeneration of natural resources. On Sept. 20, 1933, the Interdepartmental Committee was reorganized into the Committee on Preserves under the presidium of the All-Russian Central Executive Committee (in 1938 its control was transferred to the Council of People’s Commissars of the RSFSR), and in 1939 it was reorganized into the Central Board for Preserves of the Council of People’s Commissars of the RSFSR. Similar boards were organized at the councils of people’s commissars of the other Union republics. In addition to managing preserves, the Central Board for Preserves was charged with monitoring various departments and adopting measures to ensure the rational use of valuable objects, primarily of living nature. However, the measures adopted were primarily concerned with biological matters and had little to do with other aspects of conservation work.

In the late 1950’s, conservation entered a new stage with the updating and expansion of conservation legislation. During the period 1957–63, all the Union republics adopted conservation laws, which focused not only on the problems of living nature but also on the entire aggregate of natural conditions and natural resources with due regard for their interrelations; in addition, the laws dealt with the problems of protecting not only the natural features that are preserved (withdrawn from economic use) but also the natural resources that are being exploited. The conservation laws also stress the need to ensure the extensive regeneration of natural resources.

The late 1960’s ushered in a new era in conservation with the formulation of the basic principles of all-Union legislation pertaining to the protection and use of the resources and conditions of all aspects of nature. The laws passed included the Basic Principles of Land Legislation of the USSR and the Union Republics (1968), the Basic Principles of Public Health Legislation of the USSR and the Union Republics (1969; conservation of air, drinking water, and the like), the Basic Principles of Water Legislation of the USSR and the Union Republics (1970), the Basic Principles of Legislation of the USSR and Union Republics on Mineral Resources (1975), and the Basic Principles of Forest Legislation of the USSR and the Union Republics (1977).

The management of resource use in the USSR takes into account the multifaceted importance of natural resources; a distinction is made between resources that are expended during extraction, use, and processing (nonrenewable resources) and environmental resources that are important for the conservation of the soil, water, and the like. The Council of Ministers of the USSR and the councils of ministers of the Union republics have issued a series of decrees regulating various sectoral or regional aspects of conservation and outlining long-term conservation programs. The decrees include On Measures for the Prevention of the Pollution of the Volga and Don Rivers (Dec. 31, 1964), On Measures for the Prevention of the Pollution of the Caspian Sea (Sept. 23, 1968), On Measures for the Preservation of the Natural Complexes of the Lake Baikal Basin and Their Rational Use (Jan. 21,1969), and On Measures for the Prevention of the Pollution of the Basins of the Volga and Ural Rivers by Contaminated Waste Water (March 1972). The most complete solution to the problem of conservation is provided by the decree of the Supreme Soviet of the USSR On Measures for the Further Improvement of the Conservation of Nature and the Rational Use of Natural Resources, adopted in September 1972, and the decree of the Central Committee of the CPSU and the Council of Ministers of the USSR On Strengthening Conservation Efforts and Improving the Use of Natural Resources, adopted in December 1972. In the current phase of the development of the national economy and scientific-technological progress, the conservation and rational use of natural resources are becoming the key state tasks.

Among the measures expected to ensure effective protection of the environment are the comprehensive use of natural resources, the introduction of technological processes that eliminate harmful wastes, the use of biological methods to decontaminate water and control agricultural pests, afforestation, and land improvement. Also essential are scientific predictions of the possible consequences of future resource use, the development of measures to prevent impairment of the environment, and the improvement of planning, since the proposed conservation measures are a constituent part (since 1947) of the long-range and annual plans for the development of the national economy for all the ministries and departments and for the country as a whole. Actual conservation measures must be carried out by technical means that are the equal of the measures used to exploit natural resources. A powerful technical base using the latest scientific advances is being developed to protect the environment. Low-waste and waste-free production facilities and closed production cycles are being introduced, the production of synthetic substitutes for natural materials is expanding, planning is being improved, and the production of equipment and monitoring and measuring devices for decontamination units is increasing.

Resource inventory in the USSR is ensured by a system of cadastres, for example, the land cadastre and the water cadastre, and by state evaluations of the status of reserves and extraction of mineral products. On Oct. 16, 1974, the Ministry of Agriculture of the USSR instituted the Red Book of the USSR to protect rare and endangered plants and animals.

The USSR has made great advances in conservation. Clear and multifaceted conservation legislation, high public awareness, and public activism help keep the environment productive, attractive, and capable of providing for the growing needs of the population and the economy for raw materials, energy, water, and food. However, the successes of conservation have been tempered by a number of shortcomings. Some damage inflicted in the past to the natural environment in the USSR was unavoidable, for example, during the Great Patriotic War and in the first postwar years. Some damage has resulted from miscalculations and mistakes in planning. There have also been instances of mismanagement and even the existence of exploitative attitudes toward nature (for example, poaching). Much of this has been the result of the insufficient use of the opportunities available in the socialist system to further conservation.

Protection of individual components of nature and natural resources,AIR. The basic principles of legislation of the USSR and the Union republics pertaining to public health and the republic conservation laws include measures to protect the air from pollution. Air is protected as the habitat of man and all terrestrial organisms, as a condition of human health, and as a substance that participates in technological production processes (air contaminated by chemical and mechanical impurities may be unsuitable for use in technology). Protection of the air also entails protecting the organic world against the effects of harmful chemical and mechanical impurities in the atmosphere. To prevent the pollution of air by smoke, dust, gases, and other impurities, purification units are used in industry and municipal services, and production technology is being improved to minimize wastes or render them harmless. Enterprises that pollute the atmosphere are built outside populated points, and industry and transportation are gradually changing over to the use of clean fuels and sources of energy. The planting of trees and shrubs in cities and along roads and the development of suburban green zones improve air quality. Health standards stipulate the maximum allowable concentrations of harmful gases and other harmful impurities in the atmosphere. The air-pollution supervisory service imposes penalties on those responsible for pollution, and penalties may go as far as prohibiting or halting the operation of polluting enterprises.

WATER. The conservation of water resources is included in the Basic Principles of Water Legislation of the USSR and the Union republics and in special articles on conservation in the republic laws.

Surface waters serve a variety of purposes: they provide water to the population and the national economy, they are a source of energy, they serve as transportation routes and the habitat of aquatic plants and fish and other animals, and they serve as hunting areas and places of recreation and tourism and as a source of therapeutic remedies. For these reasons, their regime is subject to regulation, and the waters themselves are worthy of protection against pollution, contamination, and depletion.

Measures for the protection of water resources and for their rational use are based on the study of the water management balance. Water users must see to it that water is used economically, resources are renewed, and water quality is improved, and to this end various technological, forest-improvement, agrotechnical, hydroengineering, and other measures are carried out. Enterprises, municipal facilities, and other such installations cannot operate without purification units. Special measures are being taken to prevent the contamination of water by fertilizers and toxic chemicals washed away from agricultural lands. Improvements in production technology, such as the use of waterless production processes and the recycling of water, help reduce waste-water runoff.

The depletion of water resources can be prevented by the introduction of measures to regulate and maintain favorable regimes in various bodies of water and rivers, for example, the establishment of water-protection zones and hydroengineering and land-improvement measures. When operating water reservoirs and water-intake structures, the inflow and outflow of water is regulated with due regard for the needs of other water users.

Special attention is given to protecting the seas and lakes, first and foremost the Caspian and Black seas, the Sea of Azov, and Lake Baikal. The task in these cases is not just the maintenance of clean water and biological productivity but also the maintenance of a constant water volume. The maintenance of the level of the Caspian and Aral seas and Lake Balkhash involves solving broader, multifaceted problems of the national economy, including the regulation of the flow of the sources that feed these bodies of water, resorting even to the interbasin transfer of water.

In the basins of the Black Sea and the Sea of Azov, important work is under way to eliminate the discharge of household and industrial waste products into the seas. Conservation measures for the Sea of Azov also include those to forestall further increases in the sea’s salinity and to restore fish productivity. The protection of the seas in the USSR is a constituent part of global efforts to protect the world ocean, and consequently international cooperation plays a significant part. Measures to protect the seas involve not only objects located directly in the sea but also the coastal regions, which can affect marine bodies of water.

Subterranean waters are a constituent part of the unified state water supply and one of the components of the earth’s interior, and consequently their conservation is envisioned by the Basic Principles of Water Legislation of the USSR and the Union Republics, the Basic Principles of Legislation of the USSR and the Union Republics on Mineral Resources, and various republic laws.

As a source of drinking water and water for economic use, subterranean waters are protected primarily against chemical, bacterial, and thermal pollution; steps are also taken to prevent the nonrational use of reserves (for example, in free-flowing springs). Chemical pollution poses the largest threat, since it can spread considerable distances and can remain effective for a long time. A system of preventive measures helps protect subterranean waters against pollution: the siting and equipping of enterprises such that the harmful effects on subterranean waters are mitigated, the prevention of the contamination of surface waters and the air, the sealing off of waste flows, treatment of water, and the establishment of water-protection zones in regions where subterranean waters form and where they are used intensively. Measures to protect subterranean waters against contamination are subdivided into localized measures (restriction of the movement of pollutants through a water-bearing stratum) and restorative measures (the pumping out of polluted waters and flushing with clean water and special solutions).

The struggle against existing pollution is realistically feasible only in areas where pollution is not widespread, since it requires significant outlays of capital and a great deal of time.

GEOLOGICAL RESOURCES. Geological resources are protected by the Basic Principles of Legislation of the USSR and the Union Republics on Mineral Resources. Their conservation includes their comprehensive geological study and the observance of established procedures for their exploitation in order to extract minerals efficiently and maintain the industrial value of deposits, as well as for needs unrelated to the working of deposits (maintenance of excavations and underground structures, prevention of contamination of mineral resources in the course of constructing underground structures and burying industrial wastes, and preservation of segments of the interior that are of special scientific or cultural value).

The task of conserving mineral resources differs from that of conserving other systems of the biosphere, since mineral resources are not renewable. Thus, attention is focused on the rational use of mineral deposits. This envisions the reduction of quantitative and qualitative losses of useful minerals during extraction and processing; the comprehensive use of mineral raw materials; and the development of efficient methods of extracting and processing nonpayable ores and making use of production wastes and the enclosing rocks.

Opencut mining achieves the most complete extraction of deposits. Mineral losses are reduced in underground mining using mining systems with the backfilling of the excavation space. Non-payable ores may be extracted using geotechnological methods, that is, through openings drilled from the surface. To improve the utilization of mineral reserves, monetary incentives for complete and good-quality extraction are provided, while penalties for excessive losses are imposed. The conservation of mineral resources also includes the prevention of the adverse effects of underground excavations on the natural landscape, for example, cave-ins. Natural and artificial geological outcrops are protected, as well as geological, mineralogical, paleontological, and other natural sites of scientific, cultural, or aesthetic value.

LAND. Conservation of land, including soils, is ensured by the Basic Principles of Land Legislation of the USSR and the Union republics, as well as by republic codes and legislation.

Soviet law protects all land that is part of the land resources of the USSR. Land users are required to carry out whatever agro-technical, land-improvement, and hydroengineering measures a particular area requires to preserve the soil cover and improve soil fertility. This is done through the use of effective farming systems and crop rotations, the irrigation, flushing, and drainage of lands, and the introduction of measures to prevent water and wind erosion, bog formation, and salinization. In addition, shelterbelts are established to protect fields, and sandy soils and gullies are stabilized.

Special attention is given to the restoration of land areas disturbed by mining operations to a condition suitable for agriculture, forestry, fishing, or some other purpose, such as public recreation.

FLORA. Conservation of the flora includes the protection of forests and other natural vegetation, as well as the protection of forest-park shelterbelts, suburban green zones, and planted areas in populated points. It is provided for by the republic conservation laws.

Forests are not just a source of timber. They are an important part of the environment possessing “intangible uses”; for example, they help conserve water, soil, and fields and help purify the air. They also serve as the habitat of many wild animals. The use of forests is regulated to maintain their productivity and usefulness. Legislation prohibits the cutting of trees (except for management purposes) in forests that are important for soil, field, and water conservation and water regulation and in forests along spawning bodies of water and streams; it also prohibits the clear-cutting of mountain forests and the use of methods of timber transport that damage forest soils and the undergrowth.

In the USSR, forests are subdivided into three groups according to cutting conditions. The first group includes forests of the green zones of cities and resorts and protective strips along rivers and transportation routes, where cutting is allowed only for improvement and regeneration. The second group includes forests of the densely populated areas of the European USSR and certain areas of Siberia, where logging is allowed with restrictions. The third group includes the forests of densely wooded areas, where there are only a few specific restrictions on cutting. Forest management and logging are planned with due regard for the need to preserve and regenerate forests. Increasingly more logging is being carried out in timber-rich regions to prevent over-cutting in areas where the forests have been significantly reduced.

In addition to forests, other types of natural vegetation are protected as well, particularly vegetation that serves as a source of food for domestic and wild animals and as a source of food products and industrial, including medicinal, raw materials for man. Natural vegetation stabilizes and enriches the soil and, as part of the natural environment, influences climate and water regimes. Protection is given not only to certain rare and endangered plant species but also to the plant gene pool as a whole, which serves as a reserve of species for possible future cultivation and for use in selection research. The use of natural nonforest plants is also regulated to maintain and increase productivity. The time required for the development of a grass cover is taken into account when using pasturelands, and the order and regularity of grazing is planned.

FAUNA. Wildlife conservation is based on republic conservation laws and on a series of decrees, including the decrees of the Council of Ministers of the USSR On Measures for Improving Game Management (May 11, 1959) and On the Replenishment and Protection of Fish Stocks in Internal Soviet Waters (Sept. 15, 1958), the Statute for the Protection of Fish Stocks and the Regulation of Fishing in Soviet Waters (Sept. 15, 1958), and the decree of the Council of Ministers of the RSFSR On Measures for the Protection of the Animals of the Arctic (Nov. 21,1956).

Protection is accorded first and foremost to wild animals that are objects of the hunting, whaling, fishing, and other industries and to animals that are important as exterminators of harmful animals and as the source of food (prey) of commercially valuable animals. Rare and endangered animal species and the faunistic gene pool as a whole are of great value to science.

Legislation requires the strict observance of established rules for hunting and fishing; the improvement in the living and reproduction conditions of wildlife; and the regulation of the use of commercially valuable animals and the maintenance of conditions suitable for their reproduction. It is illegal to kill noncommercial wild animals that do not inflict damage on the economy or that do not adversely affect human health. Wildlife conservation does not preclude the regulation of harmful animals, but many predators are themselves protected as natural regulators of the ecological balance. Wildlife conservation has made it possible to restore populations and resettle many animals that had become rare (elk and beaver) or that are endangered (saiga and aurochs) and to increase the population and commercial importance of valuable furbearers (northern fur seal and sable).

PROTECTED NATURAL REGIONS. Among the protected natural regions are typical or unique examples of natural conditions in the landscape zones and regions that are of scientific, cultural, educational, historical, or aesthetic interest and that have a salutary effect on human health. They also include rare and interesting objects of living and nonliving nature and tourist and excursion areas. Preserves, which serve, in a sense, as laboratories for the study of naturally occurring processes, are accorded special protection.

In addition to the preserves, protected natural regions include game preserves, special natural landmarks, unique forests, national, natural, and memorial (historical-natural) parks, resort areas, and protected belts along popular hiking trails.

With the growth of tourism, the problem of protecting natural landscapes against overuse has arisen and trends toward urbanization have emerged. The economic and cultural-educational interests of the development of tourism itself as a sector of the economy and culture provide incentive to maintain the integrity and attractiveness of landscapes. In 1978 there were 123 preserves and four national parks in the USSR.

REGIONAL ASPECTS OF CONSERVATION. The USSR is characterized by a great diversity of natural landscapes and resources, the result of a number of factors: the vastness of the country’s land and water areas, the country’s location in different geographic zones (arctic, subarctic, temperate, subtropical) and numerous natural zones, and the effects of a multitude of azonal influences. These very same factors are responsible for significant differences in the dynamics of the development, productivity, and vulnerability of the natural world from place to place and, consequently, for the diversity of problems and methods of conservation under different zonal conditions. In addition to the general tasks of conservation, there are specific tasks, associated with unique zonal and local features.

TUNDRA AND FOREST TUNDRA. In the tundra and forest tundra, with their harsh climatic conditions that are close to extremal for living organisms (short growing seasons, low temperatures, strong winds, frozen soils), the organic world is highly vulnerable. The slow growth and maturation of organisms makes the regeneration of flora and fauna difficult should they be destroyed. Burnt tundras (pyrogenic tundras) require a particularly long time for regeneration. Frozen ground and boggy ground are irreversibly altered as a result of traffic by caterpillar-type vehicles. Aboveground pipelines cut across the migratory paths of reindeer herds.

Among the tasks faced by conservation in these regions are above all the protection of the surface against off-road traffic, the restriction or prohibition of the cutting of trees in the forest tundra and on the northern boundary of the forests, the protection of tree stands, shrubs, mosses, and lichens from fires, the prevention of overgrazing by reindeer, and the maintenance of the natural migratory paths of various wild animals. An additional special problem is the protection of the frozen ground against warming influences, which destroy or weaken it, and other disturbances of its characteristic thermodynamic balance, since frozen soils provide the base for buildings and roads and are used to construct underground storage facilities.

FOREST ZONE. In the forest zone the principal tasks of conservation are linked with forest-protection measures. Special problems of protecting natural features against chemicals arise when toxic chemicals are carelessly used to control forest pests and bloodsucking insects. In this case, forest protection measures are directed at preventing the incidental killing of birds and useful insects and averting soil contamination. The vast bogs typical of the forest zone are the object of land reclamation work, primarily drainage; however, complete drainage must be avoided because it leads to excessively dry land, impedes the continuous feeding of rivers, and destroys hunting and berry-picking areas.

FOREST-STEPPE AND STEPPE ZONES. Among the conservation problems unique to the forest-steppe and steppe zones are protection against water and wind erosion, dust storms, and salinization of soils and the maintenance of field-protection shelterbelts. The isolated forests and gallery forests on the southern boundaries of the forest’s distribution deserve special protection, as do sections with steppe vegetation that have survived among the cultivated fields.

SEMIDESERTS AND DESERTS. In the semideserts and deserts of the temperate subtropical belts, the most important conservation measures are directed at the prevention of the deflation of stabilized sands, the maintenance of sand-protection and wind-protection plantings, and the prevention of secondary salinization of topsoils and subsoils and the overgrazing of pasturelands, which are especially vulnerable owing to the extreme deficiency of moisture in deserts.

MOUNTAINS. In mountain landscapes, which are characterized by altitudinal zonality, conservation efforts are associated with the need to maintain the soil-protection role of vegetation. The destruction of vegetation on steep slopes leads to the erosion of topsoils and subsoils, which are then washed away; this results in the irreversible alteration of the topography and, possibly, in the formation of badlands. Measures to protect people, roads, and populated points, as well as forests and animals, against landslides are also part of the conservation efforts in the mountains.

Specific conservation measures are needed for azonal and intrazonal landscapes, such as caves, regions of ancient and modern volcanic activity, and fantastical shapes created by weathering. As natural landmarks, such landscapes are accorded preserve status to protect them, for example, the Kungur Peshchera, the Novyi Afon Cave, the Valley of Geysers on Kamchatka, and the Krasnoiarsk Columns.

State and public organizations. In the USSR conservation work is conducted by specialized statewide bodies: the State Planning Committee of the USSR (which has a department of conservation), the State Committee for Science and Technology of the Council of Ministers of the USSR (which includes the Interdepartmental Science and Technology Council on Complex Problems of Conservation of the Natural Environment and Rational Use of Natural Resources), and the Ministry of Agriculture of the USSR (which includes the Central Board for Conservation, Hunting, and Preserves).

A number of other ministries and state committees have narrower functions, involving the protection of particular components of the environment, for example, the Ministry of Land Reclamation and Water Use Management of the USSR, the Ministry of Geology of the USSR, the State Committee for Supervision of Work Safety in Industry and for Mining Supervision of the Council of Ministers of the USSR, the State Forestry Committee of the Council of Ministers of the USSR, the Ministry of Fisheries of the USSR, the Ministry of Public Health of the USSR, and the State Committee on Hydrometeorology and Monitoring the Natural Environment of the Council of Ministers of the USSR.

In addition, there are specialized comprehensive and branch committees and commissions in the Union republics. Both houses of the Supreme Soviet of the USSR have permanent commissions on conservation.

Conservation research is carried out by many research establishments of the Academy of Sciences of the USSR, as well as by the V. I. Lenin All-Union Academy of Agricultural Sciences, the hydrometeorological services of the ministries and departments, the preserves, and the universities and other educational institutions. The fundamentals of conservation are included in the curricula of secondary schools, many technicums, and universities and other higher educational institutions (usually related to the problems of resource use in the particular specializations). The Conservation Society, Geographic Society of the USSR, All-Union Znanie Society, and other voluntary organizations play an important role in educating the public about conservation. The USSR takes an active part in various international conservation efforts.

Bibliography