Province of the forest-steppe of the Volga Upland. The elevated watershed areas of the Volga Upland cause the active development of erosion processes, which determined a significant density of deep valleys of rivers, beams and ravines. In comparison with the province of the Oka-Don lowland, the indigenous rocks are significantly influenced by the formation of natural complexes - marls, flocks, chalk, clays. Only in the lower parts of the slopes they overlap with low-power quaternary formations, which arose as a result of weathering of the indigenous rocks. In the edge part of the Volga Upland, which was subject to the influence of ancient glaciers, low-density morainic loams are widespread.
The climate of the Privolzhsky Upland differs little from the climate of western Mordovia - moderately continental. Winter is moderately cold and snowy, summer is moderately warm and moderately wet. The formation of the local climate is markedly affected by the relief. In the lowered forms of relief, the number of days in spring and autumn with frost is greater, and in the winter period, the stagnation of cold air causes a more significant lowering of temperature. The relief and vegetation cover influence the redistribution of precipitation, especially snow. It descends into ravines, beams and other depressions.
The largest water flow in this part of the Volga Upland is the Sura River, flowing along the south-eastern border of the republic. Its tributaries on the territory of Mordovia are Alatyr, Piana, Cheberchinka, Ksh, Shtyrma. They have significant biases and a fairly high flow velocity. In the marginal part of the Volga Upland, the valleys of the rivers Insara and Nui (the right tributaries of Alatyr), as well as Issa and Sivini (the right tributaries of the Moksha) are laid. The regime of rivers is typically Eastern European with the highest water discharge in the spring in the snowmelt period.
In the water supply of settlements, underground waters of the Carboniferous-Permian aquifer are actively used, which in most of the province are of good quality. Significant problems in the drinking water supply of large settlements arose for eastern Mordovia, where groundwater has increased mineralization.
A characteristic feature of the nature of the Volga Upland is a well-marked slope change of landscapes from natural complexes of meadow steppes with chernozem soils on the lower slopes to forest areas with gray forest soils. In this part of Mordovia, the following geographical types of terrain are distinguished.
1. Elevated residual-dividing massifs in the central part of the Volga Upland with absolute elevations from 240 to 337 m, composed of carbonate and siliceous-carbonate rocks, with gray forest crushed soils under broad-leaved forests. Weak stability of natural complexes to the development of erosion processes, comparatively low natural fertility of gray forest gravelly soils, determined their relatively small agricultural development. In the south-east and south of Mordovia, where these landscapes are common, there are arrays of broad-leaved forests. Pastures and haymaking occupy a significant share in the structure of agricultural lands.
2. The central parts of the basins of the rivers of the left tributaries of the Sura (Shtyrmy, Kshi, Cheberchinki, etc.), composed of deluvial loams with chernozems. The area is well developed. Along the rivers strips are inhabited by settlements.
3. Low sectional areas of secondary morainic and lower parts of the slopes of erosion-denudation plains with absolute elevations from 210 to 240 m, composed of loams, with gray forest soils and small arrays of chernozems. The rather high natural potential of these landscapes caused their more active agricultural development, as a result, a more dense network of settlements was formed here than in the complexes described above. In these natural complexes there are small massifs of oak forests, which often narrow ribbons along the beams descend to river valleys.
4. The central parts of river basins with absolute heights of up to 210 m, composed of deluvial loams, with chernozems. In the early periods of economic development of the territory of Mordovia here were spread meadow steppes. High fertility of soils and good supply of surface and groundwater identified significant agricultural development of natural complexes. Here are placed the most valuable agricultural land of Mordovia. Along the rivers, almost continuous stripes are inhabited by settlements. This is especially characteristic of Priinsarya.
Forest province of the Oka-Don lowland. The boundary of the province of the Oka-Don lowland is determined by the spread of water-glacial sands. They determined the dominance of gently sloping terrain, complicated by shallow wide river valleys and beams. Sandy lowlands stretch in a narrow strip in the north-eastern part of the republic along the left bank of Alatyr, giving the nature of this region a great similarity with the landscapes of western Mordovia.
The climate of the province differs little from the climate of eastern Mordovia. It is moderately continental, moderately moist. Winter is moderately cold, snowy. Summer is moderately warm.
The wide distribution of water-glacial and ancient alluvial sands provides good filtration of atmospheric precipitation. This causes the formation of stable groundwater flows. On the lenses of clay formed vapors. Differences in the depth of occurrence of groundwater determine a large mosaic in the degree of moistening of natural complexes.
Unloading of groundwater forms a fairly dense hydrographic network: rivers, lakes, marshes. The predominant part of the rivers of the physico-geographical province belongs to the Moksha basin. The largest water streams are Sivin, Kivcha, Varma, Urkat, Satis, Vad.
The sand composition of the sediments and the flatness of the relief in combination with coniferous-broadleaf vegetation determine the predominance of sod-podzolic soils in the soil cover structure. Their characteristic feature is relative poverty with nutrients. Gray forest soils are less widespread.
The vegetation cover of the water-glacial plains is characterized by a combination of taiga and broad-leaved flora. The predominant type of forests are pine forests. With an increase in the degree of moistening in the presence of clay interbeds, fir trees appear in the sands, and mixed forests, oak-lime with pine and spruce, are widespread in habitats with great soil fertility.
In the province of mixed coniferous-broad-leaved forests of the Oka-Don lowland with absolute elevations of up to 190 m, the following geographical areas are distinguished.
5. Low-wavy plains, composed of sands with sod-podzolic soils under coniferous and mixed forests. A distinctive feature of the landscapes is the fairly wide distribution of the tracts of peat bogs, in the plant cover of which there are northern species. Characteristically, the presence of small villages associated with forestry activities, holiday homes, sanatoriums, etc. Natural complexes have a weak agricultural development.
6. Low-wavy plains, composed of sands underlain by limestones and dolomites, with sod-podzolic soils under coniferous and mixed forests. The hollow forms of the relief of karst origin are characteristic. These natural complexes are spread on the interfluve of Moksha and Alatyr in northwestern Mordovia, where the Mordovian state nature reserve is located. Against the background of forest massifs small areas of agricultural lands are distributed here.
The natural potential of landscapes of mixed forests of water-glacial plains is favorable for forestry and recreational activities. This is the area of supply of artesian waters of the Saransk deposit of groundwater, which in this area is not protected from pollution, therefore, in case of economic development, water protection measures should be envisaged.
Natural territorial complexes of valley landscapes.
7. Terraces wavy surfaces, with eolian relief forms, composed of ancient alluvial deposits with podzolic, sod-podzolic and underdeveloped sandy soils under coniferous and mixed forests, which are limited to plowing.
8. Terraces slightly wavy surfaces, composed of ancient alluvial deposits overlapped by deluvial loams with gray forest soils and podzolized chernozems under broad-leaved forests, selectively developed.
9. The terraced low-wavy surfaces, composed of ancient alluvial deposits overlain by the cloak of deluvial and loess-like loams with chernozem-meadow soils and leached chernozems under meadows and meadow steppes, highly developed.
10. Floodplain complexes.
LANDSCAPE DYNAMICS
A characteristic feature of the nature of Mordovia is the manifestation of the seasonal rhythm of the state of landscapes. This is reflected not only in the peculiarities of weather change, but also in the state of all components of the landscape: the intensity of the development of relief-forming processes, in regimes of rivers and reservoirs, soil formation, changes in vegetation and fauna.
Winter conditions of landscapes are observed between dates when the average daily air temperature is kept below 0 ° С. Beginning from the third decade of November, precipitation falls mainly in the form of snow, and its largest reserves accumulate by the end of February - beginning of March. The flow of rivers is formed mainly due to the development of groundwater reserves, interconnected with the water of the channel network. A winter low-water season is established, the deepest before the beginning of the next spring flood. At the end of winter, in the so-called pre-spring period, rooks arrive.
With a stable transition of the mean daily temperature through 0 ° C, the snow cover descends in 2-4 days. In connection with this, water is rising on the rivers. Melt waters on the slopes activate erosion processes, especially on agricultural lands. With the beginning of spring related phenomena such as the dusting of alders, the arrival of starlings. At the end of April - beginning of May the birch begins to grow green, in the middle of May the bird cherry blooms. Later, all leaves the oak leaves. During this period, the air is usually the last frost. With the establishment of the spring state of the landscapes, flight of birds wintering in the south begins, many of them arrange nests in the ecosystems of Mordovia. In the forest-steppe landscapes, the passage of the main phases of the development of nature is faster than in the forest.
The change in the spring conditions of nature is reflected in the appearance of landscapes: as a result of the snow cover, the white spring is replaced by a yellow, or bare, spring, lasting until the appearance of leaves, and then green, or clothed.
Summer in the territory of Mordovia begins in late May with the transition of average daily temperatures through +15 ° C. The amount of precipitation increases, rainfalls often occur, but due to the large evaporation in the beginning of June a stable low water level is established on the rivers, which lasts until the beginning or the middle of October. Rainfall is rarely accompanied by active erosion of soils, since the soil cover is covered with vegetation. When the continental air masses invade, the air temperature may rise to +39 ° C. Water in rivers warms up to +20 ° С. In late June, many plant species are beginning to bear fruit. In July, mainly the growth of woody and many herbaceous plants is completed, the latter begin to die. During the summer, some flowering types of grass replace others, determining to a certain extent the color of the landscape. At the end of August, and more often in early September, the leaves start to turn yellow.
Autumn begins with the transition of the average daily air temperature through +10 ° C, when the first frosts appear on the soil. There is a change in the summer color of the leaves in most trees for the autumn. In the second half of October, the birch, and then the broad-leaved species, are discarded. In the beginning of autumn swifts fly first to the south, and behind them and other migratory birds. The pre-winter period begins, which continues until the average daily temperature changes through -5 ° C. The amount of precipitation decreases in autumn as compared to summer, they fall out in the form of rain, snow, wet snow, ice groats. Stable snow cover is usually set at the end of November.
Autumn landscapes of Mordovia are very picturesque, especially during the Indian summer with clear, warm days and golden autumn, when the dense greenery of coniferous pine forests combines with yellow and crimson paints of deciduous forests.
The climate of the Privolzhsky Upland differs little from the climate of western Mordovia - moderately continental. Winter is moderately cold and snowy, summer is moderately warm and moderately wet. The formation of the local climate is markedly affected by the relief. In the lowered forms of relief, the number of days in spring and autumn with frost is greater, and in the winter period, the stagnation of cold air causes a more significant lowering of temperature. The relief and vegetation cover influence the redistribution of precipitation, especially snow. It descends into ravines, beams and other depressions.
The largest water flow in this part of the Volga Upland is the Sura River, flowing along the south-eastern border of the republic. Its tributaries on the territory of Mordovia are Alatyr, Piana, Cheberchinka, Ksh, Shtyrma. They have significant biases and a fairly high flow velocity. In the marginal part of the Volga Upland, the valleys of the rivers Insara and Nui (the right tributaries of Alatyr), as well as Issa and Sivini (the right tributaries of the Moksha) are laid. The regime of rivers is typically Eastern European with the highest water discharge in the spring in the snowmelt period.
In the water supply of settlements, underground waters of the Carboniferous-Permian aquifer are actively used, which in most of the province are of good quality. Significant problems in the drinking water supply of large settlements arose for eastern Mordovia, where groundwater has increased mineralization.
A characteristic feature of the nature of the Volga Upland is a well-marked slope change of landscapes from natural complexes of meadow steppes with chernozem soils on the lower slopes to forest areas with gray forest soils. In this part of Mordovia, the following geographical types of terrain are distinguished.
1. Elevated residual-dividing massifs in the central part of the Volga Upland with absolute elevations from 240 to 337 m, composed of carbonate and siliceous-carbonate rocks, with gray forest crushed soils under broad-leaved forests. Weak stability of natural complexes to the development of erosion processes, comparatively low natural fertility of gray forest gravelly soils, determined their relatively small agricultural development. In the south-east and south of Mordovia, where these landscapes are common, there are arrays of broad-leaved forests. Pastures and haymaking occupy a significant share in the structure of agricultural lands.
2. The central parts of the basins of the rivers of the left tributaries of the Sura (Shtyrmy, Kshi, Cheberchinki, etc.), composed of deluvial loams with chernozems. The area is well developed. Along the rivers strips are inhabited by settlements.
3. Low sectional areas of secondary morainic and lower parts of the slopes of erosion-denudation plains with absolute elevations from 210 to 240 m, composed of loams, with gray forest soils and small arrays of chernozems. The rather high natural potential of these landscapes caused their more active agricultural development, as a result, a more dense network of settlements was formed here than in the complexes described above. In these natural complexes there are small massifs of oak forests, which often narrow ribbons along the beams descend to river valleys.
4. The central parts of river basins with absolute heights of up to 210 m, composed of deluvial loams, with chernozems. In the early periods of economic development of the territory of Mordovia here were spread meadow steppes. High fertility of soils and good supply of surface and groundwater identified significant agricultural development of natural complexes. Here are placed the most valuable agricultural land of Mordovia. Along the rivers, almost continuous stripes are inhabited by settlements. This is especially characteristic of Priinsarya.
Forest province of the Oka-Don lowland. The boundary of the province of the Oka-Don lowland is determined by the spread of water-glacial sands. They determined the dominance of gently sloping terrain, complicated by shallow wide river valleys and beams. Sandy lowlands stretch in a narrow strip in the north-eastern part of the republic along the left bank of Alatyr, giving the nature of this region a great similarity with the landscapes of western Mordovia.
The climate of the province differs little from the climate of eastern Mordovia. It is moderately continental, moderately moist. Winter is moderately cold, snowy. Summer is moderately warm.
The wide distribution of water-glacial and ancient alluvial sands provides good filtration of atmospheric precipitation. This causes the formation of stable groundwater flows. On the lenses of clay formed vapors. Differences in the depth of occurrence of groundwater determine a large mosaic in the degree of moistening of natural complexes.
Unloading of groundwater forms a fairly dense hydrographic network: rivers, lakes, marshes. The predominant part of the rivers of the physico-geographical province belongs to the Moksha basin. The largest water streams are Sivin, Kivcha, Varma, Urkat, Satis, Vad.
The sand composition of the sediments and the flatness of the relief in combination with coniferous-broadleaf vegetation determine the predominance of sod-podzolic soils in the soil cover structure. Their characteristic feature is relative poverty with nutrients. Gray forest soils are less widespread.
The vegetation cover of the water-glacial plains is characterized by a combination of taiga and broad-leaved flora. The predominant type of forests are pine forests. With an increase in the degree of moistening in the presence of clay interbeds, fir trees appear in the sands, and mixed forests, oak-lime with pine and spruce, are widespread in habitats with great soil fertility.
In the province of mixed coniferous-broad-leaved forests of the Oka-Don lowland with absolute elevations of up to 190 m, the following geographical areas are distinguished.
5. Low-wavy plains, composed of sands with sod-podzolic soils under coniferous and mixed forests. A distinctive feature of the landscapes is the fairly wide distribution of the tracts of peat bogs, in the plant cover of which there are northern species. Characteristically, the presence of small villages associated with forestry activities, holiday homes, sanatoriums, etc. Natural complexes have a weak agricultural development.
6. Low-wavy plains, composed of sands underlain by limestones and dolomites, with sod-podzolic soils under coniferous and mixed forests. The hollow forms of the relief of karst origin are characteristic. These natural complexes are spread on the interfluve of Moksha and Alatyr in northwestern Mordovia, where the Mordovian state nature reserve is located. Against the background of forest massifs small areas of agricultural lands are distributed here.
The natural potential of landscapes of mixed forests of water-glacial plains is favorable for forestry and recreational activities. This is the area of supply of artesian waters of the Saransk deposit of groundwater, which in this area is not protected from pollution, therefore, in case of economic development, water protection measures should be envisaged.
Natural territorial complexes of valley landscapes.
7. Terraces wavy surfaces, with eolian relief forms, composed of ancient alluvial deposits with podzolic, sod-podzolic and underdeveloped sandy soils under coniferous and mixed forests, which are limited to plowing.
8. Terraces slightly wavy surfaces, composed of ancient alluvial deposits overlapped by deluvial loams with gray forest soils and podzolized chernozems under broad-leaved forests, selectively developed.
9. The terraced low-wavy surfaces, composed of ancient alluvial deposits overlain by the cloak of deluvial and loess-like loams with chernozem-meadow soils and leached chernozems under meadows and meadow steppes, highly developed.
10. Floodplain complexes.
LANDSCAPE DYNAMICS
A characteristic feature of the nature of Mordovia is the manifestation of the seasonal rhythm of the state of landscapes. This is reflected not only in the peculiarities of weather change, but also in the state of all components of the landscape: the intensity of the development of relief-forming processes, in regimes of rivers and reservoirs, soil formation, changes in vegetation and fauna.
Winter conditions of landscapes are observed between dates when the average daily air temperature is kept below 0 ° С. Beginning from the third decade of November, precipitation falls mainly in the form of snow, and its largest reserves accumulate by the end of February - beginning of March. The flow of rivers is formed mainly due to the development of groundwater reserves, interconnected with the water of the channel network. A winter low-water season is established, the deepest before the beginning of the next spring flood. At the end of winter, in the so-called pre-spring period, rooks arrive.
With a stable transition of the mean daily temperature through 0 ° C, the snow cover descends in 2-4 days. In connection with this, water is rising on the rivers. Melt waters on the slopes activate erosion processes, especially on agricultural lands. With the beginning of spring related phenomena such as the dusting of alders, the arrival of starlings. At the end of April - beginning of May the birch begins to grow green, in the middle of May the bird cherry blooms. Later, all leaves the oak leaves. During this period, the air is usually the last frost. With the establishment of the spring state of the landscapes, flight of birds wintering in the south begins, many of them arrange nests in the ecosystems of Mordovia. In the forest-steppe landscapes, the passage of the main phases of the development of nature is faster than in the forest.
The change in the spring conditions of nature is reflected in the appearance of landscapes: as a result of the snow cover, the white spring is replaced by a yellow, or bare, spring, lasting until the appearance of leaves, and then green, or clothed.
Summer in the territory of Mordovia begins in late May with the transition of average daily temperatures through +15 ° C. The amount of precipitation increases, rainfalls often occur, but due to the large evaporation in the beginning of June a stable low water level is established on the rivers, which lasts until the beginning or the middle of October. Rainfall is rarely accompanied by active erosion of soils, since the soil cover is covered with vegetation. When the continental air masses invade, the air temperature may rise to +39 ° C. Water in rivers warms up to +20 ° С. In late June, many plant species are beginning to bear fruit. In July, mainly the growth of woody and many herbaceous plants is completed, the latter begin to die. During the summer, some flowering types of grass replace others, determining to a certain extent the color of the landscape. At the end of August, and more often in early September, the leaves start to turn yellow.
Autumn begins with the transition of the average daily air temperature through +10 ° C, when the first frosts appear on the soil. There is a change in the summer color of the leaves in most trees for the autumn. In the second half of October, the birch, and then the broad-leaved species, are discarded. In the beginning of autumn swifts fly first to the south, and behind them and other migratory birds. The pre-winter period begins, which continues until the average daily temperature changes through -5 ° C. The amount of precipitation decreases in autumn as compared to summer, they fall out in the form of rain, snow, wet snow, ice groats. Stable snow cover is usually set at the end of November.
Autumn landscapes of Mordovia are very picturesque, especially during the Indian summer with clear, warm days and golden autumn, when the dense greenery of coniferous pine forests combines with yellow and crimson paints of deciduous forests.