Khingansky Nature Reserve, Russia

Khingansky Nature Reserve is a state natural reserve. It is located in the extreme southeast of the Amur region within the Arkharinskaya lowland and the spurs of the Maly Khingan ridge. Created on October 3, 1963. The total area is 97,073 ha, the area of ​​the buffer zone is 27,025 ha. Number of sites: 3.

The flat part of the reserve makes up about 70% of its total area, the rest falls on the spurs of the Small Khingan. On the flat part of the reserve there are many small lakes, the largest of which are Dolgoe, Swan and Peresheechnye lakes. The climate in the area of ​​the reserve is continental with monsoon features. Winter with little snow, but with severe frosts. The territory of the reserve is classified as a wetland of international importance. The main purpose of the creation of the Khingan Nature Reserve is to protect the forest-steppe landscapes of the Southern Amur region, as well as the nesting sites of the Ussuri (Japanese) and Daurian cranes.



The reserve was established in 1963. For those who are a little familiar with the history of Russian reserves, this may seem surprising, because the period of another government attack on reserves has just passed, when many reserves were liquidated by one government decree in 1961 and many more lost a significant area. The paradigm of that time in relation to nature was enrichment and transformation, and reserves with their inviolability did not fit well into the rhythm of the times. And now, two years after their defeat in the Far East, 4 reserves are created at once: Bolshekhekhtsirsky, Komsomolsky, Zeya and Khingansky. The initiative to create them belonged to A.S. Khomentovsky Chairman of the Far Eastern Branch of the Academy of Sciences of the USSR Corr. He proposed the creation of a new type of reserves (similar to national parks), placing them near large industrial centers: Khabarovsk, Komsomolsk-on-Amur, Obluchye and in the area of the Zeya hydroelectric power station under construction. Oddly enough, this initiative quickly materialized (Shtilmrak, 1996).

Although the Khingan Reserve was conceived as a place of recreation for the inhabitants of the developing city of Obluchye (fortunately, it was not destined to become a major industrial center until now), the choice of territory turned out to be very successful. The geographical position at the junction of the spurs of the Lesser Khingan and the Arkharin lowland, in the zone of interpenetration of several floristic and faunal complexes, determined the enormous diversity of its biocenoses, the richness of flora and fauna. Later, in the early 70s, nesting sites of the rarest birds of the world - the Japanese crane and the Far Eastern white stork - were discovered in this territory, and the importance of the Khingan Reserve increased dramatically (Darman, Bochkarev, Andronov, 1990).

The original area of the reserve was 58.9 thousand hectares. It was located in the extreme southeast of the Amur Region in the Arkharinsky District, from the north it was limited to the Trans-Siberian Railway, from the south it did not reach the river. Amur. Prior to the creation of the reserve, apiaries were located on this territory, their number reached 12, most of these apiaries ceased to exist even before 1963 due to unprofitability. Since 1945, timber has been harvested (oak, aspen, ash, birch, acacia, conifers), in addition, velvet bark has been harvested. So, basically the forests of the reserve were cut down, only deep, hard-to-reach ravines remained untouched. On flat areas, hay was actively harvested, cattle were grazing.

Only in 1976 the reserve acquired the status of an independent state institution, with all the ensuing rights and opportunities. So it became possible to purchase their own equipment, increase the staff of the forest guard, and create their own scientific department.

In 1978, a site between the Arkhara and Bureya rivers (now Antonovskoye forestry) was attached to the reserve, a valuable territory for nesting cranes and storks. This happened thanks to the efforts of ornithologists Pankin N.S., Smirensky S.M., Vinter S.V., Flint V.E. and work of the staff of the reserve. They were supported in this by the world community, the archive of the reserve still contains a letter from the famous naturalist B. Grzimek to the government about the importance of preserving this site.

In 1982, another large section between the Uril and Gryaznaya rivers was added to the reserve, and the border of the reserve acquired its modern outline. To date, the reserve consists of three forest areas, in addition, the natural monument "Lotus Komarov" and the ornithological reserve "Ganukan" are subordinate to the reserve.


Flora and fauna

The Khingan Reserve is one of the last surviving fragments of the once majestic animal and plant world of the Middle Amur region, praised by many explorers.

The reserve is located in the zone of a smooth transition of the low mountains of the Lesser Khingan ridge into the endless expanses of the Amur humid forest-steppe on the Arkharin lowland. The height of the mountains of the reserve is slightly more than 500 meters. Fast, rocky rivers in the upper reaches carry their waters in narrow canyon-like valleys, after reaching the plain, their channels become extremely tortuous and sometimes hide under the swamps. The climate of the reserve is continental with monsoon features. This means that a cold, with frosts down to -40 Celsius, and little snowy winter, is replaced by a dry spring and a hot, humid, relatively long summer.

Here, in the reserve, on excursion trails, an inexperienced observer can wander through the tall grass of the relic East Asian prairies, see more than one group of grazing roe deer, admire rare birds and blooming lotuses. The richness of plant communities and landscapes of the reserve determines the diversity and high abundance of individual species of mammals on his territory. The largest local group of wild boar in the Amur Region (up to 1000 individuals) lives here.

In the mountains of the reserve, during the period of the red deer roar, you can hear up to 10 bulls from one cordon. In spring, among the open areas of swamps and meadows, an observer can count 15-40 roe deer in one evening within sight. On the trails there are often traces of brown and Himalayan bears, wolves and lynxes, and recently - the Far Eastern forest cat. More recently, in the last century, a tiger also lived here. In winter, the snow cover in the coniferous forests is dotted with numerous traces of squirrels and sables, and the surface of the ice of the rivers is covered with footprints of otters and minks.

From the point of view of an insect specialist, the Khingan Reserve is located in a very interesting place. During the last cold snap, the Bureya-Khingan lowland was not completely covered by a glacier, and some of the heat-loving relics have survived to this day: the Far Eastern hermit, the relict woodcutter, the ascalaf. The geographical location of the territory in the place of interpenetration and overlapping of faunas characteristic of the Far East contributes to the coexistence of faunal complexes here.

The fauna of the reserve's insects is poorly studied; to date, more than 1750 species belonging to 97 families have been registered, but this list, according to some experts, can be safely increased by 2-3 times.

The location of the territory of the reserve within two types of landscapes, flat and low-mountain, determines the contrast of the vegetation cover. The plain part of the reserve is, first of all, vast expanses of sedge, reed grass, forb meadows interspersed between them with islands of forest from flat-leaved birch, Daurian birch, and Mongolian oak. In the second half of June - early July, when the xiphoid iris, the small beauty, the bathing suit, the real bedstraw, the wiki, the meadows are blooming with a whole palette of colors.

Sedge, sedge-moss bogs from Meyer's sedge and mosses of the sphagnum genus, confined to the most lowered relief elements, are no less significant here in terms of the area occupied. Numerous lakes with original coastal aquatic vegetation are scattered among meadows, swamps and forests. Here grow such relic species as Komarov's lotus, Schreber's brazilia, floating walnut, small egg-pod, tetrahedral water lily.

In the low-mountain part of the reserve, against the background of the absolute predominance of Mongolian oak forests, relatively small areas are occupied by coniferous-broad-leaved forests with Korean pine. They are at the northwestern limit of their distribution. In addition to Siberian pine, white fir, Siberian and Ayan spruce, Amur linden, yellow birch, maples and other species participate in the composition of the forest stand.

Larch forests grow in small areas along steep slopes and wet valleys. In May, they are given out by the lilac flame of a flowering rhododendron. Alder forests are found along the floodplains, in the valleys, at the sources of springs. The channels of mountain rivers are, as a rule, framed by dense thickets of willows and bird cherry, abruptly giving way to sedge-reed grass meadows in the floodplain itself.

The flora of vascular plants of the reserve currently includes 967 species, of which 19 are listed in the Red Book of the Russian Federation. 442 species of algae, 579 species of fungi, 63 species of lichens, 149 species of mosses are also registered on the territory of the reserve.

The Khingan Reserve is inhabited by birds of different ecological groups.

Numerous near-water bird species nest on the flat territory, of which the killer whale and mallard, the Far Eastern curlew, the great chauffeur, the three-fingered crane, the Japanese and Daurian cranes, the gray heron, the great cormorant, the Far Eastern stork, the Amur bittern and dozens of other species. Songbirds are most abundant in the mountain forests of the reserve.

Both in the mountains and on the plains, the role of East Asian endemics is great. The diversity of birds of prey is impressive, with many vulnerable protected species such as the Greater Spotted Eagle, White-tailed Eagle, Spotted Harrier and Marsh Harrier.

Every year, in spring and autumn, hundreds of thousands of feathered migrants visit the reserve. Among the birds migrating through its territory, such rare species as the black crane, swan goose and lesser white-fronted goose are regularly noted.

In general, more than 20 species of birds listed in the Red Book of Russia nest or visit during the migration season in the reserve. Its role is especially great in maintaining the nesting populations of the Japanese and White-naped cranes and the Far Eastern stork.

The reserve is home to 6 species of amphibians: 1 species of tailed amphibians (Siberian salamander), 2 species of toads, 2 species of frogs and 1 species of tree frog.

Reptiles are represented by a viviparous lizard, a Far Eastern tortoise, 3 species of snakes (including the largest Amur snake in Russia) and 2 species of muzzle. The latter, although poisonous, but even in the absence of medical care, their bite is not fatal. The stories about the long jumps of these snakes are greatly exaggerated - the snake can lunge no more than a third of its body length.

It is easy to distinguish a poisonous snake from a non-venomous one by the shape of the pupil, in snakes it is round, and in poisonous snakes it is slit-like, “cat-like”.

On the territory of the reserve, 28 species of fish were noted, of which minnows, silver carp, rotan, loach, mustards are the most common.



The Khingan State Reserve is located in the extreme south-east of the Amur Region within the Khingan-Arkharinskaya Lowland, which is a continuation of the Zeya-Bureya Plain, and the foothills of the Lesser Khingan Ridge. The reserve consists of two sections: a branch, which is located in the interfluve of the Bureya and Arkhara rivers, and the main territory.

In the scheme of geomorphological zoning (Nikolskaya, Yarmolyuk, 1969), the Khingan Reserve is located within two areas: the Amur-Zeya-Bureya intermountain plain (the Zeya-Bureinskaya lacustrine-alluvial plain area) and the area of medium-altitude and low Mesozoic mountains and intermountain plains of the left-bank Amur region (area low massive mountains of Lesser Khingan and Turan). The mountainous territory of the reserve (Khingan forestry) L.N. Miskina (1971) refers to the Far Eastern broad-leaved landscape type, and the flat territory of the main part of the reserve (Lebedinskoye forestry) and the branch (Antonovskoye forestry) to the Far Eastern forest-steppe type.

The geological structure of the mountainous part of the reserve mainly involves effusive and ancient sedimentary rocks: Lower Proterozoic amphibolites, gneisses and crystalline schists (Nikolskaya and Yarmolyuk, 1969; Nikolskaya, 1981). The hills occupy a significant part of its territory, the average height of their peaks is 200-400 m above sea level. seas. The highest point on the territory of the reserve is Mount Erakticha (504 m). To the south of these hills, the hilly-ridge-ridged relief turns into a gently sloping, slightly inclined foothill relief, which directly adjoins the plain, which accounts for almost 70% of the total area of the reserve.

The Arkharin lowland is an alluvial-proluvial plain. Its formation took place by transgressive elongation of the Amur and Bureya tributaries, which deposited clastic material carried by them from the territory of the low mountains in the regime of random unloading (Likutov and Gusev, 1992). The proluvial deposits, together with the accumulation and later, to varying degrees, underwent significant processing both by the rivers that deposited them and by the main rivers, the Amur and Bureya.

The lowland is composed of Quaternary lacustrine-river deposits of heavy mechanical composition (total thickness up to 40 m) (gleyed yellow-gray clays and heavy loams) of the Amur valleys and its left tributaries - Arkhara, Mutnaya, Urila, Gryaznoy, Khingan (Miskina, 1968). The exception is the Boguchanka hill, which is a basalt island hill. The deposits of the Amur have the greatest distribution within the lowland. The age of these deposits is determined from the Upper Quaternary to the modern. The Middle Quaternary deposits of the Amur are developed very limitedly along the northern periphery of the lowland. They form the third terrace above the floodplain. Upper Quaternary presumably lacustrine-alluvial deposits are very widely developed and form the first (8.5-13 m high) and second (15-25 m high) floodplain terraces. Modern deposits of the Amur River form high (3-8.5 m) and low (2-3 m) floodplains of the Amur. The valleys of the left tributaries of the Amur, incised into the Amur terraces, are filled with modern deposits, forming in some places an unexpressed high (4-5 m) and low (1.5-2 m) floodplains. The slopes of the lowland surface are minimal, rarely reaching 2-3°.

The relief of the Khingan-Arkharin lowland is characterized by the alternation of small elevations (rivers), which are the remains of coastal ridges (Voskresensky, Kostomakha, 1973), and areas with varying degrees of waterlogging (Nasulich, 1958; Likutov, Gusev, 1992). They most often have a fan-shaped planned configuration. “Fans” diverge from the rivers that go out onto the plain, and either continue each other or overlap each other in lateral sections. Their length reaches more than 10 km.

The floodplain is developed almost everywhere in the river valleys. Its width is from 50-100 m to, possibly, 1.2-1.6 km (the mouth part of the Erakta River; the Uril River at its exit to the plain), on average - 100-300 m. Relative height - 1- 2m, less often - up to 2.5-3m. As a rule, it is complicated by a hummocky-hollow microrelief (amplitudes up to 1-1.2 m, on average 0.4-0.5 m) on the plain and hummock-depressive, hilly-depressive (amplitudes up to 0.6-0.8 m, on average - 0.2-0.4) in the lowlands. The floodplain is composed of thin (from 0.4 to 1 m) thin clastic alluvium of the Holocene age, below which lies the channel alluvium of the Holocene and, possibly, of an older age.

The first terrace above the floodplain is fragmentary. Its average width in the valleys of small rivers of the low mountains is 200-300 m, the maximum is 500 m, and in the valley of the river. Uril, at its exit from the low mountains to the plain - possibly up to 900 m. The length of individual fragments is up to 400-500 m, less often - up to 2 km; in the valleys of the Uril and Gryaznaya rivers, when they exit the low mountains to the plain, it can reach 7.5-8.5 km. The surface of the terrace is sub-horizontal (slope - rarely up to 2-3?), sufficiently moistened, less often dry, in depressions, especially during rainy seasons - excessively moistened. Often the surface is complicated by a hilly-depression microrelief (amplitudes up to 0.4 m).



In the early Proterozoic, an underwater marine plain extended on the site of the future Zeya-Bureya Plain and the Lesser Khingan Range (Khudyakov, 1972). In the Malokhingansky region, mainly sandy-argillaceous, less often volcanogenic-sedimentary deposits accumulated. The actual appearance of the Lesser Khingan structure, composed of sedimentary rocks, dates back to the early Paleozoic.

In the Middle Paleozoic, in the Amur-Zeya region of sedimentation, weak oscillatory movements begin with a general tendency to subsidence. At this time, mainly terrigenous and shallow-water strata are formed here, volcanic activity is very insignificant and local in nature (Beltenev, Krasny, Yarmolyuk, 1966). At the end of the Silurian and in the Lower Devonian, within the Amur-Zeya plate, the formation of orographically pronounced uplifts with a folded structure (Mamynskoe and Gonzhinskoe uplifts) occurs. Here, sediments accumulated in shallow, but intensely subsided basins with active underwater volcanic activity. Thanks to it, volcanic surface structures were formed, which were subsequently subjected to ground denudation. In place of the modern Zeya-Bureya lowland, an accumulative marine plain extended with a much more stable subsidence and predominantly terrigenous accumulation during the Silurian, the entire Devonian, and the Lower Carboniferous.

From the Middle Paleozoic in the Malokhingansky region, intense orogenic processes began, which culminated in the Late Mesozoic (Khudyakov, 1972). At that time, along with active processes of magmatism, there was an accumulation of volcanogenic-sedimentary and sedimentary strata. The relief was a complex terrain, consisting of volcanic uplifts and lava plateaus, as well as steep valley plains with streams wandering along the swampy floodplain.

The inversion uplift of the Amur-Zeya basin, which began in the Late Paleozoic and was accompanied by denudation processes, continued until the Lower Cretaceous. In the Volgian, systems of grabens (superimposed depressions) arose on its territory, separated by denudation plains or hills (Nagibina, 1963). Intensely sagging grabens were quickly filled with proluvial-alluvial continental coarse clastic deposits. From the Early Cretaceous begins the expansion and consolidation of troughs, burial under the increasing area of the sedimentary cover of interdepression spaces. This leads to the formation here in the Late Cretaceous of an extensive alluvial plain with a wide distribution of lakes and swamps, the contours of which were in general close to modern ones. Volcanic activity in the territory of the basin has ceased. The processes of leveling (peneplenization) continued during the Paleogene and Neogene and reached a maximum by the beginning of the Anthropogen.

Within the limits of the Lesser Khingan mountain structure, since the Late Cretaceous, during the Paleogene and Neogene, there has been a decrease in the intensity of orogenic processes.

At the end of the Neogene and the beginning of the Anthropogen, the leveling of the relief of the Amur-Zeya depression continues against the background of slow subsidence of the plain, which is compensated by sedimentation (Khudyakov, 1972). The most intense subsidence occurred in the southern part of the depression, in the area of the lower reaches of the Zeya and within the Amur valley. By the end of the Pleistocene, the general subsidence of the depression gradually slows down and is replaced by an environment of relative tectonic stability. In the future, depression begins to rise. There is an incision of rivers and the formation of a series of floodplain terraces in their valleys.

In the Quaternary, orogenic processes continue in the Malokhingansky region (Kulakov, 1972).

As for the formation of river basins, it should be noted that the establishment of the Amur drainage system cannot be attributed to any particular period of time (Khudyakov, Kulakov, Korotkiy, 1972). The formation of its individual fragments took place in different eras. The Amur Valley in the middle reaches (within the Amur-Zeya depression) was formed mainly in the Late Cretaceous.



The climate in the area of the reserve is continental with monsoon features (Vitvitsky, 1969). In the scheme of climatic zoning, the study area is located in the temperate zone of the monsoon forest (and forest-steppe) region of the southern subregion (Alisov, 1956).

The weather here during the summer is influenced by the North Pacific anticyclone, the South Asian cyclone, and cyclones passing through the continent (Kositsyn, 1959). Such an arrangement of the main centers of action of the atmosphere is caused by summer monsoons - southeast winds blowing from the sea to land. They bring in a lot of moisture. The abundance of precipitation in summer depends on the action of the North Pacific anticyclone. During periods when the anticyclone is located near the Asian mainland, masses of warm, moist sea air are brought to the mainland along its southwestern periphery. In this case, the South Asian cyclone and cyclones passing through the continent are activated and heavy rains fall on the territory of the region. When the North Pacific anticyclone is near the coast of North America, the South Asian cyclone and cyclones passing through the continent do not receive enough moisture and give little precipitation.

In winter, the weather usually depends on the influence of the Siberian anticyclone. During cold periods, the main core of the Siberian anticyclone is located in the region of the Central Siberian Plateau; during periods when winters are with moderate frosts, it moves to the Baikal region, and in case of warming it stays in the eastern part of Mongolia. Therefore, in winter, north-western winds blowing from land to sea prevail in the reserve. These are the winter monsoons bringing clear, dry and cold weather.

Winter is clear frosty, low windy with little precipitation. The average monthly temperature is -23.6°. The average snow depth is 18-27cm. A small layer of snow and low temperatures in winter contribute to deep freezing of the soil. Snow cover, as a rule, is established in late October - early November. Spring and autumn are dry and windy. In some years there is an excess of moisture. Summers are hot, with a lot of clouds and a significant amount of precipitation. The average monthly temperature is 18.8°. Often the second half of summer is excessively wet.

The total solar radiation is from 83 to 98 kcal/cm2 year. The total number of hours of sunshine is from 2000 to 2500 per year, of which during the growing season (May-September) falls from 1000 to 1200 hours (Kositsyn, 1959).

L.F. Nasulich (1958) classifies the territory of the reserve as a temperate humid region. Precipitation falls mainly from April to October. In winter, precipitation is 6% of their annual amount (about 40 mm). The largest amount of precipitation occurs in July - August. With heavy rain showers, 40-50 mm can fall per day. The total amount of precipitation for the year is 637 mm (Kastrikin, 2000).

The annual course of relative air humidity has two maxima - in winter (December) and summer (August) and two minimums - in spring (May) and autumn (October). During the year, an average of 5-7 periods with atmospheric drought are observed, the longest of which last an average of 5-7 days (Spravochnik ..., 1982). The average duration of a frost-free period in the reserve area is 133 days, and the duration of the growing season is 132 days ( Kastrikin, 2000).



The soils of the Khingan Reserve, as well as the entire Amur Region, belong to the Amur monsoon facies (Liverovsky, 1969). According to the soil-geographic zoning of the former USSR (Dobrovolsky, Urusevskaya, 1984), the territory of the reserve is part of the Eastern brown soil-forest region, the zone of brown and podzolic-brown forest soils of coniferous-deciduous forests. At the same time, the Arkharinskaya lowland belongs to the Zeya-Bureya plain province of brown forest and meadow-chernozem-like soils, and the spurs of the Lesser Khingan belong to the South Sikhote-Alin mountainous province of mountain-brown forest and mountain-brown forest podzolized soils (Pshenichnikov, 1986).

Meadow-marsh and meadow gley soils are widely represented in the Arkharinskaya lowland (Miskina, 1971). These are meadow soils with a whitish eluvial horizon, which are formed under conditions of seasonal temporarily excessive surface moisture (Liverovsky, 1969). Meadow gley soils are usually located in slightly elevated areas (Ivanov, 1966). They form under damp and fresh, but not overmoistened, forb-reed grass and shrub forb-cereal meadows, under tall-grass aspen-birch forests, and under dwarf birch forests. These soils are characterized by a rather high content of humus (6-15%), high exchange capacity, acidic, sometimes slightly acidic and close to neutral reaction of the environment. Meadow-marsh soils, as a rule, are confined to depressions. They differ from meadow soils in a more pronounced and more stable excess surface moisture. In some years, their waterlogging lasts for almost the entire growing season. Their morphological features are a strong turfing of the surface horizons of the soil, the appearance of a peat layer, and a clearly pronounced gleying throughout the soil profile. These soils differ in the nature of the accumulative-humus horizon. They are usually formed under moss-sedge and sedge-reed grass vegetation (Miskina, 1971). Meadow-brown (soddy-meadow) soils are developed to a limited extent under upland legume-forb-grass meadows (Kachiyani and Tregubov, 1960; Koretskaya, 1962).

Brown forest soils are confined to the most elevated and drained relief elements, which occur in small areas among meadow and meadow-marsh soils. Brown forest soils are developed under oak forests and black birch forests, as well as under shrub thickets of hazel hazel and steppe legume-forb-cereal meadows that arose in the place of these forests.

V.A. Kovda et al. (1957) list the following features of the biological cycle of landscapes of cold prairies and oak-black-birch forests of Primorye and Amur Region, which include the landscape of the Arkharin lowland: a large amount of substances involved in the biological cycle, high intensity of the cycle, almost complete neutralization of organic acids. During soil formation, large amounts of humic substances are accumulated with a predominance of the humic acid fraction associated with calcium, secondary clay minerals, and a large amount of secondary silica; plumes and lower terraces accumulate compounds of iron and manganese, the most important micro- and macroelements.

Mountain-brown forest soils are developed in the mountainous part of the reserve under broad-leaved and coniferous-broad-leaved forests. They are characterized by the following features: thin litter (1-3 cm), the presence of an accumulative organo-mineral horizon, which is impregnated with humic substances and has a gray or even black color with a brownish tint and always contains both strongly decomposed and fresh plant remains (Ivanov , 1976). The soils are slightly acidic, sometimes even slightly alkaline. The researchers attribute the pH shift towards an alkaline reaction to the passage of fires, after which a significant amount of ash with a high content of alkaline elements remains. The humus content ranges from 4-17%.

Modern soil-forming processes in the area of the reserve are meadow, marsh and brown earth (Liverovsky, Rubtsova, 1959). The process of burozem formation in its pure form develops only on well-drained landforms. Even a slight deterioration in drainage or an insignificant lateral inflow of soil-ground moisture causes the appearance of a discolored, and sometimes a pronounced whitish horizon in the soil profile. The soils of the study area are formed under conditions of maximum moisture and temperature in the summer-autumn period and, conversely, at their minimum values in the autumn-winter and spring periods. The consequence of this is a high humus content of the surface horizon, often at a low thickness, as well as a high accumulation of absorbed nitrogen bases and some other elements of the ash plant nutrition (Ivanov, 1976).

The Khingan Reserve is located in a zone of water erosion dominance, with a moderately dissected relief under conditions of moderate and strong erosion, very strong and excessive erosion, and moderate deflation (Onishchuk, Kharnina, 1997).



The water network of the reserve is represented by the left tributaries of the Amur in its middle course: Uril, Mutnaya, Gryaznaya, Khingan with Udurchukan and small, often unnamed tributaries of these rivers. In the protected area, the tributaries of the Amur flow in the middle and lower reaches and are distributed fairly evenly. The average density of the river network is 0.3-0.4 km per 1 km2 (Miskina, 1973).

Most of the rivers in the lower reaches are of the flat type, but in the upper reaches they have the character of mountain rivers: with narrow valleys, stony channels and fast currents. The river bed is usually straight, only in the middle reaches of relatively large rivers (Mutnaya, Gryaznaya, Uril) is it meandering. Channel width on small rivers - a few meters, on larger ones - 7-12 m, maximum (on the plain) - up to 15-23 m. Depth - from 0.2-0.4 m on rifts to 2-3 m on reaches . The flow velocity on mountain rivers is up to 1.5 m/s, on larger rivers of the plain 0.5-0.7 m/s. Channel alluvium in the plains is represented by sand and often unsteady silt, and in the low mountains - gravel, pebbles, sand (Likutov, Gusev, 1992).

In the annual regime, the share of rain supply is 75-80%, snow - 15-20% and 5-8% of the runoff falls on groundwater. Due to the predominance of rain feeding, river runoff on rivers is extremely uneven throughout the year. So, in the annual runoff, winter runoff (November-March) is 3-7%, spring (April-May) - 15-20%, the largest runoff is observed in the summer-autumn season and amounts to 75-80% (Nasulich, 1958). Small streams freeze to the bottom, and the flow in them completely stops. In this case, swelling of ice and the formation of powerful ice dams are observed. All reservoirs in the reserve have a stable ice regime. Summer rain floods sometimes turn into floods, which are repeated every 10-12 years and are caused by the spill of the Amur and Bureya.

The rivers of the flat territory are assigned to the group with increased turbidity (50-100 g/m3), and the mountain rivers to the group with turbidity less than 50 g/m3 (Resources..., 1966). Average monthly values of water temperature of rivers in the lower reaches reach 8-10°C in May, 14-18°C in June, and 22°C in July-August. The rivers Karapcha, Mutnaya, Erakta in some areas do not freeze all winter. The thickness of ice on the rivers of the reserve usually does not exceed 30-40 cm, and on lakes - 50-70 cm (Andronov, 1998).

On the flat part of the reserve and near it there are many small lakes of oxbow origin. Lakes are of the type associated with the erosion-accumulative activity of rivers. The maximum level is observed most often in August-September. The water is very warm in summer, due to the shallow depth of the lakes. As a rule, lakes have an elongated oval or rounded shape. The average depth of small lakes is 1 m (Shulman, 1959), larger ones 2-3 m. In dry years, the lakes dry up so much that some of them can be forded.

Groundwater belongs to the Zeya-Bureya Artesian basin (Skornyakov et al., 1969). .5 g/l) (Yusupova, 1999). According to the concentration of hydrogen ions, the reaction of the medium varies from acidic to alkaline. In terms of hardness, both artesian and ground waters are soft. Groundwater is predominantly low-ferruginous with an iron concentration of 0.3 to 1.6 mg/l. The increased content of manganese in both artesian and groundwater is confined to the valleys of the Arkhara and Bureya rivers.