Communication on the topic of natural zoning. Natural zoning of the land fund. Finished works on a similar topic
The vast size and evenness of the relief determine the clear expression of geographic zoning in Africa. From the equatorial belt to the North and South, the subequatorial, tropical and subtropical belts are successively replaced by the subequatorial, tropical and subtropical belts, and in East Africa the equatorial belt is weakly expressed due to local relief conditions and is usually replaced by the subequatorial. North of the equator, where moisture decreases from subtropical and subequatorial latitudes to tropical, geographic belts and zones are mainly extended latitudinal. South of the equator, the latitudinal or near-latitudinal strike of belts and zones is observed only in the interior regions of Africa; along sea coasts, under the influence of oceanic climates, they usually extend meridional or submeridional.
The equatorial belt occupies the coast of the Gulf of Guinea and the Congo depression (between 6 ° - 7 ° north latitude and 4 ° - 5 ° south latitude). In the equatorial zone with a constantly hot and humid climate, there are favorable conditions for the growth of moist evergreen and mixed (deciduous-evergreen) forests and the formation of red-yellow ferralite soils. The processes of biochemical weathering are actively taking place here. The runoff layer reaches the largest value on the mainland; a dense network of constantly full-flowing rivers is being formed.
In the subequatorial belt (up to 20 ° north latitude and 20 ° south latitude), moisture is much less and fluctuates noticeably from season to season. In this belt, there is a narrow zone of seasonally moist (mixed - deciduous-evergreen and evergreen-deciduous) forests and a wide zone of savannas, woodlands and shrubs with three subzones - wet, dry and deserted savannas with all more xerophytic formations of deciduous forests, red wheels and shrubs. In this direction, the process of laterization of the soil layer is weakened, there is a sequential change of soils from red and brown-red to red-brown, the runoff layer decreases, and its seasonal fluctuations increase. In the dry season, physical weathering increases, rivers become shallow or dry up, vegetation slows down or stops vegetation. Salient feature zonal types of landscapes - the prevalence of savannas on the plains of Sudan and woodlands on the highlands of the Eastern and South Africa.
In the northern and southern tropical zones, the structure of geographic zoning is different. In the northern tropical zone, where the dryness of the climate is greatest on the mainland, an exceptional development of deserts is noted, the zone of which stretches from Atlantic Ocean to the Red Sea between 10 ° -19 ° north latitude and 30 ° north latitude. Most of this zone is occupied by the Sahara Desert. In deserts, the volume of biomass of plant and animal organisms sharply decreases, the runoff becomes negligible, episodic, the processes of physical weathering and deflation are very active.
In the southern part of Africa, humidification in the tropics noticeably decreases from East-North-East to West-South-West, in connection with which sector patterns are well expressed in the tropical belt. In the eastern near-oceanic sector, there are zones of dry forests and open woodlands; in the continental, where dryness is rapidly increasing, landscapes of deserted savannas dominate, as well as semi-deserts, which occupy about half of the Kala-hari depression. The tropical desert zone of South Africa lies almost entirely in the western sector off the coast of the Atlantic Ocean and enters into the interior of the mainland only along the lower course of the river. Orange.
In subtropical zones, the greatest dryness of the climate is noted in the interior regions (where landscapes of semi-deserts and deserts are common). On the northwestern and southwestern outskirts of the continent, on the windward slopes, under conditions of predominance of winter precipitation, landscapes of the Mediterranean type are widespread (stiff-leaved forests and shrubs on brown soils in the Atlas Mountains and mainly shrub communities in the Cape Mountains). In the southeastern outskirts of Africa, with the summer maximum precipitation, there are monsoon mixed forests.
The modern structure of landscape belts and zones has existed in Africa (in a relatively constant climate) for several millennia. However, long-term human activity - hunting, agriculture, cattle breeding - has led to a significant depletion of natural complexes. This process was especially intense during the period of the colonial regime, when the protective measures of nature management were not observed.
Tropical rainforest has shrunk, deciduous forests have almost disappeared, and forests have been cleared in the Atlas Mountains and the Ethiopian Highlands. They were replaced by savannas and greatly expanded woodlands. The area of deserts is catastrophically increasing (especially to the North of the equator), and the problem of combating desertification is acute.
Tropical rainforest has shrunk, deciduous forests have almost disappeared, and forests have been cleared in the Atlas Mountains and the Ethiopian Highlands. They were replaced by savannas and greatly expanded woodlands. The area of deserts is catastrophically increasing (especially to the North of the equator), and the problem of combating desertification is acute. See the map of natural zones and countries.
In Africa, according to a certain combination of morphostructural types of relief and zonal types of landscapes, several large natural countries are distinguished. Atlas - Hercynian-Alpine ridges flanking vast intermontane basins, with a typical Mediterranean climate and landscapes on windward slopes and semi-deserts in inland arid regions. The Sahara is the largest tropical desert in the world with extremely sparse, mainly shrub-grass xerophytic vegetation and primitive stony soils. Sudan is an area of lowland savannas, with a sharp change in natural aspects depending on the seasons - wet summer and dry winter. North Guinea Upland - horst-blocky mountains and basement plains of the African Platform salient with very humid southern windward slopes of the mountains, covered mainly with evergreen forests, and more arid northern ones, where mixed seasonally moist monsoon forests and high-grass savannas are common ... Ethiopian Highlands and Somalia Peninsula. On the Ethiopian Highlands, mostly flooded with lavas, the altitudinal zonality of landscapes is clearly traced, sharply different on the western wet and dry eastern slopes. The Afar tectonic depression is occupied by semi-deserts. On the Somali Peninsula, due to a decrease in moisture to the Indian, near evergreen forests (in the mountains of the interior regions) give way to deserted savannas, thickets of thorny bushes and semi-deserts. The Congo Basin is the inner syneclise of the platform, in the equatorial and subequatorial geographic zones. Landscapes of humid evergreen and mixed forests dominate, passing along the periphery of the depression (in the North, West and South) into humid savannas. East Africa - a plateau broken by faults and faults, with the deepest lakes and the highest peaks of the mainland, sometimes flooded with lavas, with a subequatorial climate, landscapes of deserted and typical savannas in the driest northeastern parts, wet savannas and mixed forests in wet northwest and open woodlands in the south. South Africa (often called Africa Minor, as it repeats all types of landscapes characteristic of Africa, except for equatorial ones) includes the southern edge of the African Platform with the Kalahari syneclise, as well as the Hercynian Cape Mountains. In the interior regions of South Africa, due to the decrease in moisture from North to South and from East to West, open woodlands, wet and typical savannas give way to deserted ones, which occupy most of the southern Kalahari; along the western outskirts stretch semi-deserts and deserts (Namib). The eastern coastal lowlands and slopes of the Drakensberg Mountains are wet savannas and mountainous rainforests(now almost reduced). In the Cape Mountains and on the southeastern outskirts of the mainland (up to 30 ° South latitude) there are subtropical landscapes: evergreen shrubs with highly endemic Cape flora and remnants of evergreen mixed forests.
LANDSCAPE-ECOLOGICAL AREA
Comprehensive natural (landscape) zoning is a special form of information about the natural-territorial differences between regions and serves as a natural science basis for the correct location of agricultural production. Particularly important practical significance is acquired by the fractional landscape zoning of the land fund of individual republics, administrative regions for land management agricultural purposes.
Unlike particular types of zoning (soil, botanical, agroclimatic, etc.), complex - landscape zoning is understood as the identification, delimitation and classification of natural-territorial complexes (NTC), objectively existing in nature.
A natural-territorial complex is an individual unique territorial unit characterized by a certain homogeneity of a complex of interrelated and interacting natural components (geological structure and relief, climate, waters, soils, vegetation and fauna). Leading value In the isolation of the NTC, there are tectonic and geomorphological differences in the territory that determine the degree of climate homogeneity and, through it, the features of the manifestation of other natural components. The study of the NTC is of great practical interest, since the territory of each NTC is more or less homogeneous (depending on the taxonomic rank) in terms of natural potential, that is, the possibilities of practical use.
The diversity of nature, which is characteristic of territories as a whole and can be observed in relatively large and small spaces, creates conditions for the formation of many territorial natural complexes, differing in size, qualitative and quantitative characteristics. The work on integrated natural zoning consists in a deep study of the nature and reasons for the differentiation of the landscape sphere into qualitatively different sections of the NTC, the boundaries of which the researcher is able to identify, but not change their number.
Recognition of the objectivity of the existence of natural-territorial complexes of various taxonomic rank, differing in structure, history of development, makes it possible to consider complex natural zoning as basically the same. Various tasks and goals determine the scale of regionalization, the nature of the interpretation of its materials for specific practical purposes. For example, when zoning for land management and agricultural purposes, the main task is not only to establish and study natural-territorial differences, trends modern development landscapes, taking into account anthropogenic impact, but also in determining the conformity or inconsistency of the existing structure of agricultural production with natural conditions and the potential of land resources in a particular region. This zoning helps local planners to adjust existing regional management systems. Agriculture, since in the natural-production characteristics of the selected regions, the greatest attention is paid to those natural conditions and processes that are especially important to know when organizing the agricultural use of the territory.
In other words, on the basis of general scientific natural zoning, one can create different kinds applied zoning. But even in this case, the boundaries of the NTC do not change their position; there may only be a different number of identified taxonomic units (different division of zoning), depending on the scale. In applied zoning, the properties of the landscapes of a particular region are clarified for certain practical purposes, that is, the correct interpretation of the data of general scientific zoning is carried out in a form that is available for direct use by practitioners.
Thus, integrated natural zoning as a form of accounting for soil-landscape heterogeneity of land resources should help the relevant regional and district organizations to correct the existing regional systems of agriculture in the zoning grids of the land fund, that is, to clarify them on the basis of the latest achievements of the natural sciences.
The problems of complex natural zoning are considered with all possible completeness in a special course and corresponding training manuals (Prokaev, 1983; Mikhailov, 1985; Isachenko, 1991). Of greatest interest is complex natural, or physical-geographical, or landscape, zoning, which can be considered as the most important way of synthesizing knowledge about the laws of territorial natural-geographical differentiation and integration at the regional level.The development of landscape zoning is based on the recognition of the objective nature of the independent regularities of regional physical and geographical differentiation, discussed above. Each pattern has its own system of territorial units - regions of a different order, which determine the multilayer nature of the territorial differentiation of the landscape sphere, its spatial polystructurality.
In the zonal series, some geographers (A.A. Grigoriev, V. B. Sochava, E. N. Lukashova) considered the latitudinal belt to be a taxon of the highest rank. However, in the opinion of others, there are not sufficient grounds for identifying belts as complex physical and geographical units, since their integrity is based only on circulation and thermal features. Apparently, belts should be considered auxiliary or optional units of landscape zoning, used mainly to link the zonal schemes of individual components, as well as oceans on a global scale.
The basic taxonomic unit in the zonal series is the landscape zone. (In the following text, the epithets landscape or physical-geographical in the names of taxonomic units of landscape zoning are omitted for brevity). Let us recall the continuity of the zonal structure of the landscape sphere and the gradual nature of the change of zones. This determines the vagueness of zonal boundaries, the existence of transition zones, and in addition, the formation within many zones of latitudinal bands of the second order - subzones (for example, northern, middle and southern in the taiga zone).
Taking into account the subzones, the number of landscape-zonal subdivisions (let us call them zonal stripes) increases significantly; there are up to 20 of them only on the territory of Russia. The “status” of some zonal zones, especially transitional ones (forest-tundra, subtaiga, etc.), turns out to be debatable: it is unclear whether to consider them as independent zones or to join one of the neighboring ones as subzones. The significance of such discrepancies should not be dramatized; the zone and the subzone are taxa of a very close order, and the geographical essence of the forest-tundra, subtaiga and similar objects will not change from what rank will be assigned to them.
The highest taxonomic unit of the azonal series is considered to be a country. The main criterion for identifying countries is the unity of the geotexture and the largest features of the macrorelief. There are two groups of countries - plain (for example, East European, or Russian, plain, West Siberian, North China) and mountainous (Ural, Caucasus, Mountainous country of North-East Siberia, etc.); an essential feature of the latter is the presence of altitudinal zonation. An important distinguishing feature of any lowland country is its zonal structure - a set of latitudinal zones and their longitudinal-sector features.
Countries are subdivided into areas confined to morphostructures of a higher order and isolated during the development of countries under the influence of differentiated tectonic movements, sea transgressions, continental glaciations, etc. So, within the Russian Plain, there are about 20 landscape regions (for example, Pechora, Timan, Central Russian, Polesskaya). As a rule, the regions clearly differ in the nature of the macro-relief and geological basement, the structure of the hydro-network, as well as in the azonal specificity of the climate, soils and organic world... Suffice it to compare, for example, the North-West landscape region with its various and well-preserved forms of glacial relief, an abundance of lakes, a dense but poorly developed river network, a relatively mild climate, frequent passage of cyclones, an abundance of precipitation from the neighboring Upper Volga region, where traces of glaciation are poorly preserved. , rivers flow in well-developed valleys, typical continental climate, etc. However, in the zonal relation, the area can be heterogeneous and cover parts of different zones and subzones (in both examples given, taiga and subtaiga).
With further division of the region according to azonal features, we will eventually come to the identification of azonal regions associated mainly with the main orographic elements of the region with a predominance of one type of surface rocks and sculptural forms of relief. These features are consistent with regular combinations of local locations with their characteristic soils and biocenoses. Such are, for example, in the North-Western region Ilmen-Volkhovskaya boggy lowland on tape clays, Luzhsko-Oredezhskaya, also swampy, but more elevated moraine lowland, Sudomskaya hilly-moraine upland, etc.
The described two series of regional taxa quite objectively reflect individual aspects of the territorial differentiation of the landscape sphere, but do not create a unified system of complex natural zoning. They can be viewed as partial systems containing the necessary prerequisites for the formation of the latter. The theoretical validity of the combination of partial series in a single zoning system follows from the fact that the real manifestation of each independent geographical pattern (for example, zoning) in the nature of a particular territory depends on the influence of other patterns. As we have already seen, the general features of nature inherent in this zone acquire a special regional specificity when crossing the longitudinal sectors. We observe the same in areas of the same zone located in different countries, areas and azonal areas.
Logically, we can assume that, consistently continuing the analysis of the regional structure of a zone, country or sector "from top to bottom", we will come to the selection of such territorial units in which further no zonal, sectoral or zonal differences are found, i.e. they will turn out to be homogeneous in all three criteria. This assumption is by no means a hypothesis, it corresponds to reality, and physical geographers in their research practice have been guided by it - consciously or intuitively - for a number of decades. Therefore, we are talking about a complex natural (physical-geographical) area that meets the criterion of homogeneity (indivisibility) both in terms of zonal and azonal characteristics. Many prominent geographers, in particular A.A. Grigoriev, V.B. Sochava, S.V. Kalesnik, N.A. Solntsev, call such an area a landscape and consider it the main (lower) taxonomic step in the hierarchy of physical and geographical regions.
Thus, the landscape can be characterized as the ultimate (lower), initial stage of complex natural zoning, if you approach it "from below", and at the same time, as the final, closing step, if you approach it "from above". All higher zoning units can be considered as territorial associations, or landscape systems.
In order for the system of complex natural zoning to acquire a complete character, it is necessary to determine all its higher (supra-landscape) taxonomic stages and establish their subordination, i.e. hierarchical relationships. Various methods have been proposed for constructing such a system. The most common is the so-called single-row method, based on the principle of alternating zonal and azonal units. In 1946 A.A. Grigoriev proposed the following taxonomic series: belt - sector - zone and subzone - province - landscape. Other variants of such a system are also known, some authors exclude the belt from it, others replace the sector with a country, but this does not change the fundamental essence. The alternation of zonal and azonal units is a clear convention; the apparent subordination of the sector to the belt, and the zones to the sector, contradicts logic: in nature there is no such subordination, direct subordination exists separately within each of the two rows. In fact, under the sector in A.A. Grigoriev does not mean an integral sector as a formation independent of the belt, but as a part of it within the boundaries of one belt. In the same way, the term "zone" does not mean an integral zonal strip, but its separate segment within the boundaries of a particular sector.
Thus, in the single-row system, there are no initial, or primary, zonal and azonal regions, with the exception of the one that is accepted as the highest step in the row. All other units are derived “zonal-azonal” formations. This by no means denies their reality and significance. However, the single row system does not reflect their dual subordination. Indeed: a sector in the row of A.A. Grigoriev is not only a part of the belt, as it follows from the given subordinate series, but at the same time a part of the “large” sector in the broad sense of the word, the “shortened” zone in this row is a part of the zone in the broad sense of the word and at the same time a sector; a province is part of a zone and an azonal area.
The multi-layered regional structure of the landscape sphere can hardly be reflected using a simple one-row model. Obviously, this should be a question of a multi-row model. The simplest of these can be constructed as a coordinate system or matrix. The role of coordinates is played by taxa of two main independent series of regional physical-geographical differentiation - zonal and azonal. At the intersections of both coordinates, derivative complex zonal-azonal taxa are formed, forming the third row, which plays the role of the pivot of the entire system (Fig. 14).
We will return to this system, usually called two-row, although in reality it consists of three rows, but first we note that there are attempts to build more complex regional systems.
IN AND. Prokaev proposed a system of physical and geographical zoning, consisting of six rows connected by mutual transitions: zonal, sector, barrier, altitude-belt, tectogenic (analogous to morphostructural) and landscape - derived from all the previous ones. This system appears to be unnecessarily complex. Among the patterns of territorial physical-geographical differentiation, only three are truly universal in nature - zonal, sectoral, and morpho-structural (azonal). Altitudinal zonality and barrier nature cannot be considered universal laws: unlike the other three, they do not appear everywhere, but only in special azonal conditions, in individual countries and regions, and, therefore, are particular manifestations of azonality.
In the three-row system (Fig. 13), there are five taxa of a derived or connecting landscape series, each with a double subordination, which is emphasized by the names of specific regions. (The scheme does not include some possible optional taxa transitioning from sub-province to landscape.) Three main levels of landscape zoning can be distinguished.
1. The macro level covers zones and subzones in the narrow sense of the word, i.e. “Segments” of these latitudinal formations within the borders of one country (for example, the taiga zone of the Russian Plain, the middle taiga subzone of the Russian Plain).
2. The meso-level includes provinces and sub-provinces - “stretches” of zones and subzones, respectively, within the same region (North-West province of the taiga zone, North-West sub-province of the south-taiga sub-zone).
3. The base or lower level is represented by the landscape itself or the landscape area as a nodal unit that closes all three rows and is, as it were, in their focus. The landscape often geographically corresponds to an azonal (morphostructural) region, namely, in those cases when the latter "fits" into the boundaries of one subzone or a zone that does not have subzonal division (some examples have already been given earlier). If a morphostructural region crosses the border of adjacent zones or subzones, two landscapes appear on its territory.
Rice. 13. The system of taxonomic units of physical and geographical
Zoning
There is no sector in the above diagram and this can be regarded as its disadvantage. Sector differentiation is represented by one step and does not form a special taxonomic series. Within the sector, longitudinal climatic differences of the second order can be observed, but they are reflected in the azonal boundaries - a grid of countries and regions. Thus, at the steps following the sector, the sectorial differentiation merges with the azonal one. As for the sectors themselves, their borders often run along the crests of ridges and cut mountainous countries. The territorial structure of most sectors consists of some kind of flat physical-geographical country and the slopes of the surrounding ridges facing it. Thus, the "core" of the East European sector is formed by the country of the Russian Plain. Consequently, the system of sectors to some extent duplicates the allocation of lowland countries, but at the same time it dismembers mountainous countries into parts, which creates great difficulties when trying to combine sectors and countries in one zoning system and greatly complicates it. Therefore, in practice of regionalization, the sector and the country are usually used as alternative taxa.
Each of the two options - with a sector or a country as the higher taxa of the azonal series - has its own advantages, but no fundamental differences are seen between them. The main discrepancy remains only at the macro level; in the rest, both options are identical. In the first case, the country as an independent unit is absent and is represented by its subdivisions at the level of oblasts, subordinate directly to the sector.
The use of complex natural zoning for solving various scientific and applied problems (for example, assessing the ecological state of a territory, its resource potential, economic development, etc.), as a rule, does not require taking into account all the series and taxonomic subdivisions of a multi-row system. For these tasks, it is advisable to use simplified version complex natural zoning based on some generalization of the synthesizing landscape series. The essence of such generalization is reduced to two operations: 1) subzones and “simple” zones that are not subdivided into subzones are considered as peer-to-peer units (zonal stripes), so that zones and subzones in the narrow sense of the word are combined into one taxon - a landscape macroregion; 2) sub-provinces and provinces that are not subdivided into sub-provinces are also considered as peers and are combined into one taxon - the mesoregion. As a result, we get a simple three-term taxonomic system: macroregion, mesoregion, lower region (landscape, or landscape area).
Macrozoning of the territory of Russia according to the general scheme is shown in Fig. 14 and tab. 14, which serves as a legend for the map. In the table and in the figure, landscape macroregions are indicated by numbers, their own names are made up of the names of zonal bands and sectors, for example: East European boreal mid-taiga region (4). The scheme of landscape meso-regionalization of Russia is published in the book by A.G. Isachenko (2001). The grid developed by the author of the landscape macrozoning of the entire land, consisting of 175 regions, is difficult to imagine in a readable form in a book format. In this tutorial, it served as the basis for some schemes and calculations.
Rice. 14. Landscape macrozoning of Russia (explanations in Table 14)
Table 14
Landscape macrozoning of Russia
| Zone stripe | Sector | ||||||
| Eastern European | Caucasian | West Siberian | Central Siberian | East Siberian | Central Asian | Far East | |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| Arctic | 1 | - | - | 29 | - | - | - |
| Subarctic tundra | 2 | - | 19 | 30 | 37 | - | 41 |
| Same forest-tundra | - | 20 | - | ||||
| The same forest-meadow | - | - | - | - | - | - | 42 |
| Boreal northern taiga | 3 | - | 21 | 31 | 38 | - | 43 |
| Same as average | 4 | - | 22 | 32 | 39 | - | 45 |
| Same south taiga | 5 | - | 23 | 33 | - | 46 | |
| The same subtext | 6 | - | 24 | 34 | - | - | 47 |
| Subboreal broadleaf forest | 7 | 14 | - | - | - | - | - |
The end of the table. fourteen
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Natural zoning
Dimensions of PTC Geographic envelope Continents Oceans Oceanic ridges Depressions Mountains Plains Lowlands Uplands Ravine Hill River terrace PK nest one into another
Study of the complexes The main method for identifying PTC is Physical and geographical zoning. Those. the establishment of boundaries and their subordination. Large PCs are distinguished on the basis of: A) differences in geological history; B) differences in climatic conditions.
Units of zoning A physical-geographical country is a vast part of the continent, corresponding to a large tectonic structure and quite uniform in orographic terms, characterized by a common macrocirculation processes and a peculiar structure of geographic zoning (a set natural areas or the range of altitude zones). The country covers an area of several hundred thousand or million square kilometers (Central Siberia is the largest of the countries - about 4 million km2).
Zoning units A zone in a broad sense is an area of predominance of landscapes of the same type (tundra, forest, forest-steppe, desert, etc.). In order for landscapes of the same type to form throughout its entire space, the zone must have some common features. Relief, climatic-plant community, fauna, soils.
Zoning units A province is a part of a zone or mountainous area, characterized by a common relief and geological structure, as well as bioclimatic features. Usually, a province territorially coincides with a large orographic unit - a hill, lowland, a group of ridges, or a large intermontane basin. Examples of provinces are Oksko-Don, Bugulmino-Belebeevskaya, Chulymo-Yeniseiskaya, Putorana, Central Altai, etc. Mountain provinces also differ from neighboring ones by the type of structure of altitudinal zonation.
Zoning units The region is a relatively large geomorphologically isolated part of the province, within which the integrity and specificity of the landscape structure is preserved. Each region is distinguished by a certain combination of mesorelief forms with their characteristic microclimates, soil varieties and plant communities. The region is the lowest unit of the regional level of differentiation of the geographic envelope.
Fixing Which PTC is younger. Floodplains or river valleys? Why? Name the man-made PTC. What is the PTC level of the Putorana Plateau? Name all the large NTC within which the Minusinsk Basin is located.
Homework §28, in the c / c mark the boundaries of the PTK at the level of physical and geographical countries.
Variety of natural complexes
All components of nature are closely and inextricably linked with each other. Changing one of them causes changes in others. These relationships are expressed in the exchange of matter and energy. This happens within a specific territory. Therefore, a natural territorial complex (NTC) is a natural combination of interrelated components of nature in a certain area.
Natural territorial complexes are of great practical importance for agriculture, land reclamation, recreation, construction of cities and roads. Without knowledge of the features of a particular natural complex, there can be no question of rational use, protection and improvement of the natural environment. In the hierarchy of natural complexes, three main levels are distinguished: local (facies), regional (natural zone, province), global (geographic envelope).
On the territory of Russia, there are many different PTCs. Natural, or physical-geographical, zoning serves as the main method for identifying NTC, establishing their boundaries. The selection of large NTC in Russia is based on the differences in geological structure, relief, and climate.
On these grounds, physicist-geographers usually distinguish on the territory of Russia:
1. Russian (East European) plain.
2. North Caucasus.
4. West Siberian lowland, or plain.
5. Central Siberia.
6. North-east of Siberia.
7. Belt of mountains of Southern Siberia.
8. Far East.
We will consider six large natural regions: 1. Russian (East European) plain; 2. North Caucasus; 3. Ural; 4. West Siberian lowland; 5. Eastern Siberia; 6. Far East.
Natural areas
Natural zoning is one of the main geographic patterns. The largest German naturalist Alexander Humboldt, having analyzed changes in climate and vegetation, found that there is a very close connection between them, and climatic zones are simultaneously vegetation zones. V.V.Dokuchaev proved that zoning is a universal law of nature. The existence of large natural-territorial complexes (NTC), or natural (natural-historical - according to V.V.Dokuchaev) zones is associated with zoning. Each of them is characterized by a certain ratio of heat and moisture, which play a leading role in the formation of soil and vegetation cover.
On the territory of Russia, there is a change (from north to south) of the following natural zones: arctic deserts, tundra, forest-tundra, taiga, mixed and deciduous forests, forest-steppes, steppes, semi-deserts. Almost all zones stretch from west to east for thousands of kilometers, and nevertheless, they retain common features throughout their entire length, due to the prevailing climatic conditions, the degree of moisture, soil types, and the nature of the vegetation cover. The similarity can be traced both in surface waters and in modern relief-forming processes. Academician L. S. Berg made a great contribution to the study of natural zones.
The Arctic desert zone is located on the islands of the Arctic Ocean and in the far north of the Taimyr Peninsula. A significant part of the surface is covered with ice; winters are long and severe, summers short and cold. The average temperature of the warmest month is close to zero (less than +4 ° С). In such conditions, the snow does not have time to melt everywhere in summer. Glaciers are forming. Large areas are occupied by stone deposits. The soils are almost undeveloped. Vegetation on a surface free from snow and ice does not form a closed cover. These are cold deserts. Plants are dominated by mosses and lichens. Flowering plants are few and far between. Of the animals, those that feed the sea predominate: birds and polar bears. Noisy bird colonies are located on the rocky shores in summer.
The tundra zone occupies the coast of the seas of the Arctic Ocean from the western border of the country to the Bering Strait, which makes up almost 1/6 of the territory of Russia. In some places the tundra reaches the Arctic Circle. The zone reaches its greatest extent (from north to south) in Western and Central Siberia. Compared to arctic deserts, tundra summers are warmer, but winters are long and cold. The average July temperature is +5 ... +10 ° С. The southern border of the zone almost coincides with the July isotherm + 10 ° С. Little precipitation falls - 200-300 mm per year. But with a lack of heat, evaporation is small, therefore, excessive humidification (K> 1.5). Permafrost is almost ubiquitous, which thaws in the summer by only a few tens of centimeters. In places of its deeper thawing, shallow basins are formed, which are filled with water. Without seeping into the frozen ground, moisture remains on the surface. The tundra is literally dotted with shallow and small lakes. The river runoff is also great. The rivers are full of water in the summer.
The soils of the zone are thin, tundra-gley; tundra vegetation of mosses, lichens and low-growing shrubs dominates. Not only cold and permafrost, but also strong winds are to blame for the treeless tundra. The tundra zone with scarce heat reserves, permafrost, moss-lichen and shrub communities are areas of reindeer husbandry. Arctic foxes are hunted here. There are many fish in the tundra lakes.
The forest-tundra zone stretches along the southern border of the tundra zone in a narrow strip. The average July temperature is +10 ... +14 ° С, the annual precipitation is 300-400 mm. There is much more precipitation than can evaporate, so the forest-tundra is one of the most swampy natural zones. The rivers are fed by melted snow waters. Rivers are flooded in early summer when the snow melts. Forest-tundra is a transitional zone from tundra to taiga. It is characterized by a combination of tundra and forest communities of plants and animals, as well as soils.
Diversity of Russian forests. Forests are the wilderness of spruce forests, the grandeur of oak forests, and sun-soaked pine forests, and white-trunk birch forests. Forests are distributed in two natural zones: in the taiga zone and in the zone of mixed and deciduous forests.
The taiga zone is the largest natural zone in Russia. In its different areas, many are not the same natural conditions- the general severity of the climate, the degree of moisture, mountainous or flat relief, the number of sunny days, the variety of soils. Therefore, the types of conifers prevailing in the taiga are also different, which, in turn, changes the appearance of the taiga. Dark coniferous spruce-fir forests prevail in the European part of the zone and in Western Siberia, where cedar forests join them. Most of Central and Eastern Siberia is covered with larch forests. Pine forests grow everywhere on sandy and gravelly soils. The forests of the Far Eastern Primorye have a very special character, where on the Sikhote-Alin ridge such southern species as Amur velvet, cork oak, etc. join conifers - spruces and firs. The main wealth of the taiga is the forest. The taiga accounts for 50% of Russia's timber reserves. Hydropower resources account for over 50% of the country's resources. The production of valuable furs is also almost entirely in the taiga zone.
Northern and middle taiga are characterized by a lack of heat (the sum of temperatures above 10 ° C is less than 1600 °) and poorly fertile soils. Here, as in the forest-tundra, agriculture is of a focal nature.
The southern subzone of the taiga is more favorable for agriculture, although in order to increase the fertility of the lands, they must be drained, limyed and fertilized. The conditions here are favorable for breeding cattle.
The zone of mixed and deciduous forests is located on the Russian Plain south of the taiga, is absent in the inland areas and reappears in the south Of the Far East... The soils and vegetation of the zone change when moving from north to south. In the north, there are mixed coniferous-deciduous forests on sod-podzolic soils, in the south - multi-tiered deciduous forests on gray forest soils. Far Eastern mountain broad-leaved forests are very peculiar. In them, along with Siberian species, tree and shrub species grow, characteristic of the forests of Korea, China, Japan and Mongolia. The vegetation of the zone, especially in the European part, is very much changed. Even our distant ancestors, in need of soil favorable for agriculture, began to cut down the local oak forests. Now the forest area occupies less than 30% of the total area of the zone. They include a significant share of secondary small-leaved species - birch, aspen, alder. In the place of the former forests, arable land, orchards and pastures are spread.
The forest-steppe zone is a transitional zone from forest to steppe. In the interfluves of the forest-steppe zone, broad-leaved (oak) and small-leaved forests on gray forest soils alternate with forb steppes on chernozems. The ratio of heat and moisture in the forest-steppe is close to optimal, but moisture is unstable. Droughts happen, dry winds often blow, so it is necessary to take measures to prevent their destructive impact on crops (for example, planting forest belts). The soils of the forest-steppe zone are fertile. However, with the rainfall nature of precipitation and the friendly melting of snows, the upper soil horizon is washed away, and ravines are formed in the fields. It is necessary to fight against water erosion. The nature of the zone has been greatly changed by human economic activity. In the west, the plowed area reaches 80%. Wheat, corn, sunflowers, sugar beets and other crops are grown here.
The steppe zone is small in area and occupies the south of the European part of the country and Western Siberia. On the example of the steppes, it is especially clearly seen that it is impossible to judge the moisture content only by the amount of precipitation. There is little precipitation here - from 300 to 450 mm, about the same as in the tundra zone. But the tundra is swampy and is characterized by excessive moisture. In the steppes, there is a lack of moisture. The moisture coefficient in the steppe zone varies from 0.6-0.8 (at the northern border) to 0.3 (in the south). Cyclones over the steppe are less frequent than over the forest zone. In summer, the weather is clear and sunny. High summer temperatures (the average July temperature is +21 ... +23 ° С) and strong winds cause significant evaporation from the surface and periodically occurring droughts, dry winds, dust storms that cause great damage to vegetation. Since there is little precipitation, and the evaporation rate is 2 times higher than the amount of precipitation, there are no conditions for the leaching of humus into the depths of the soil horizons. Chernozems with a very dark color and granular structure are widespread in the steppe. The thickness of the humus horizon reaches 50-80 cm. In the Kuban River basin, the boundary of this horizon is marked at a depth of 1.5 m. Chernozems are the most fertile soils in our country. In the southern strip of the steppes, dark chestnut soils are widespread, less fertile and often saline.
Currently, the steppe zone is almost completely plowed up. The stock of plant matter in the steppes is much less than in the forest zone. Due to prolonged droughts, grasses dry out and burn out by the middle of summer. That is why steppe plants have deep, branched roots, giving up to 80% of the plant mass.
The fauna of the steppes is very different from that of the taiga. Various small rodents predominate - ground squirrels, marmots, jerboas, hamsters, voles. Herds of wild horses roamed the prehistoric steppes, saigas, now pushed back into the semi-desert, bulls, completely exterminated in Eastern Europe.
The steppe is the main grain bin of the country. Wheat, corn, sunflowers and other important crops are grown here.
Semi-deserts and deserts are located in the Caspian and Eastern Ciscaucasia.
The semi-desert, like the steppe, is treeless. It has features of both steppes and deserts. The climate here is sharply continental. There is little rainfall - 250 mm per year. The evaporation rate is 4-7 times higher than the amount of precipitation. Along with the evaporated moisture, soluble substances move to the upper soil horizons, which leads to their salinization. The soils are chestnut and brown desert-steppe. Wormwood-grass vegetation predominates, sensitive to the proximity of groundwater. The soils are fertile enough, but for farming they need artificial irrigation. Semi-deserts are good pastures for sheep and camels. With the external scarcity of vegetation per year, each hectare gives 4-8 tons of organic matter.
Deserts are characterized by an even greater moisture deficit (less than 150 mm per year) and higher average temperatures in July - + 25 ° С. Summer is longer and hotter here. On average, there are at least 200 sunny days here per year. The soils are even more saline than in the semi-desert. Clay deserts are especially poorly provided with moisture, since clay retains moisture on the surface and it quickly evaporates. The moisture coefficient does not exceed 0.1-0.3.
Sparse vegetation usually covers less than half of the desert surface. There is little plant matter and it dries quickly. There is almost no accumulation of humus from the recession. The soils of the deserts are gray soils. Due to the large amount of mineral salts obtained during irrigation, they become fertile. Desert vegetation is well adapted to dry climates: plants have long and branched roots, instead of leaves with thorns.
Desert animals live in burrows or burrow in the sand. Some even hibernate in the summer and can go without water for a long time. Deserts, like semi-deserts, serve as valuable pastures for sheep and camels.
Altitudinal zonation (high-altitude, or vertical, zoning) is a natural change in natural zones and landscapes in the mountains.
Mountains are the main reason for the disruption of the horizontal arrangement of natural zones on the globe. In contrast to the plains in the mountains, both flora and fauna are 2-5 times richer in species. What is the reason for the “multi-storey” nature of natural zones in the mountains? The number of altitudinal zones depends on the height of the mountains and on their geographic location... The change of natural zones in the mountains is often compared to moving along the plain in the direction from south to north. But in the mountains, the change in natural zones is sharper and more contrasting and is felt already at relatively short distances. The largest number of altitudinal zones can be observed in the mountains located in the tropics, the smallest - in the mountains of the same height in the Arctic Circle. The nature of the altitudinal zonation varies depending on the exposure of the slope, as well as the distance from the ocean. The mountains located near the sea coasts are dominated by mountain forest landscapes. The mountains in the central regions of the mainland are characterized by treeless landscapes. Each high-altitude landscape belt encircles the mountains on all sides, but the system of tiers on the opposite slopes of the ridges is sharply different. Only at the mountain foothills are the conditions close to typical flat ones. Above them are "floors" with a more moderate, and higher and harsh nature. These floors are crowned with a tier of eternal snow and ice. It would seem that it should be warmer closer to the sun, but it turns out on the contrary - the higher, the colder.
