Geographic zonation due to the zonal distribution of solar radiant energy. Therefore, as S.V. Kolesnik, "Eonal temperature of air, water and soil, evaporation and cloudiness, atmospheric precipitation, baric relief and wind system, properties air masses, the nature of the hydrographic network and hydrological processes, the features of the geochemical processes of weathering and soil formation, the type of vegetation and wildlife, sculptural forms of relief, in to some extent, types of sedimentary rocks, and finally, geographical landscapes, combined into a system of landscape zones".[ ...]
Geographic zonality is inherent not only to the continents, but also to the World Ocean, within which different zones differ in the amount of incoming solar radiation, balances of evaporation and precipitation, water temperature, features of surface and deep currents, and, consequently, the world of living organisms.[ ...]
The foundations of the geographic zoning of soils were laid down by V.V. Do-gchaev, who pointed out that "the same zoning.[ ...]
The study geographical distribution ecosystems can only be undertaken at the level of large ecological units - macroecosystems, which are considered on a continental scale. Ecosystems are not scattered in disorder, on the contrary, they are grouped in fairly regular zones, both horizontally (in latitude) and vertically (in height). This is confirmed by the periodic law of geographical zonality of A. A. Grigoriev - M. I. Budyko: with the change of the physiographic zones of the Earth, similar landscape zones and some of their common properties are periodically repeated. This was also discussed in the consideration ground-air environment life. Statutory periodicity is manifested in the fact that the values of the dryness index vary in different zones from 0 to 4-5, three times between the poles and the equator they are close to unity. These values correspond to the highest biological productivity of landscapes (Fig. 12.1).[ ...]
The periodic law of geographical zoning of A. A. Grigoriev - M. I. Budyko - with the change of the physical and geographical zones of the Earth, similar landscape zones and some of their common properties periodically repeat.[ ...]
THE LAW OF PERIODIC GEOGRAPHIC ZONING (A. V. GRIGORYEVA - M. I. BUDIKO): with the change of physical and geographical zones, similar landscape zones and some of their general properties are periodically repeated. Dryness index values vary in different zones from 0 to 4-5; three times between the poles and the equator they are close to unity - these values correspond to the normal biological productivity of landscapes.[ ...]
Significant influence on geographic zoning is exerted by terrestrial oceans, which on the continents form longitudinal sectors (in temperate, subtropical and tropical zones), oceanic and continental.[ ...]
Logging types are characterized by geographic zoning.[ ...]
Subsequently, the radiation bases for the formation of the zoning of the globe were developed by A. A. Grigoriev and M. I. Budyko. To establish a quantitative characteristic of the ratio of heat and moisture for various geographical zones, they determined some coefficients. The ratio of heat and moisture is expressed as the ratio of the radiation balance of the surface to the latent heat of evaporation and the amount of precipitation (radiation index of dryness). A law was established, called the law of periodic geographic zoning (A. A. Grigorieva - M. I. Budyko), which states that with the change of geographical zones, similar geographical (landscape, natural) zones and some of their common properties are periodically repeated. Based on the radiation balance, the radiation dryness index, taking into account annual runoff, showing the degree of surface moistening, A. A. Grigoriev and M. I. Budyko plotted the geographic zoning of the northern hemisphere (Fig. 5.65).[ ...]
As you know, the factors that make up the climate are characterized by geographical zonality. In addition, the nature and individual properties of the climate are very importantly influenced by the distribution on the surface of the globe of land and water spaces, which forms the climates - continental and maritime. The forest also exerts its influence by shaping its own ecoclimate, or rather a series of them.[ ...]
Milkov F. N. physical geography: the doctrine of the landscape and geographical zonality. Voronezh. 1986. 328 p.[ ...]
The purpose of the work is to determine the content of mercury in soils of various geographic zoning by the method of atomic absorption.[ ...]
O. Classifications based on the principle of "latitudinal and altitudinal physical-geographical zonality"
A. Wallace's rule, from which the review in this section began, is valid for geographic zoning in general and for similar biotic communities, but only for similar ones, since the absence or presence of one or (as a rule) group of species indicates that we we are dealing not with the same, but with a different ecosystem (according to the rule of correspondence between species and cenosis - see section 3.7.1). At the same time, similar ecosystems can be within different vertical zonality - the further south, the higher mountain belts (the rule of changing vertical belts), or on slopes of a different exposure; for example, ecosystems of more northern landscape differences are formed on the northern slopes. The latter phenomenon was formally established in 1951[ ...]
The ideas of A. A. Grigoriev had, though not immediately, an impact on the entire course of development geographical science in the USSR. A number of works were carried out by him jointly with the geophysicist M. I. Budyko. The latter belongs to the works on heat balance earth's surface, the introduction of the radiation index of dryness as an indicator of bioclimatic conditions used in the justification (together with A. A. Grigoriev) periodic law geographic zoning.[ ...]
A. A. Grigoriev (1966) owns theoretical research on the causes and factors of geographical zonality. He comes to the conclusion that in the formation of zoning, along with the magnitude of the annual radiation balance and the amount of annual precipitation, their ratio and the degree of their proportionality play an enormous role. A lot of work was done by A. A. Grigoriev (1970) on the nature of the main geographical belts of land.[ ...]
The main natural feature of the Timan-Pechora region is a clear manifestation of latitudinal geographical zonality, which determines the main parameters of the ecological and natural resource potential territory (natural living conditions of the population and the quantity and quality of natural resources), and imposes appropriate requirements on the technology of territory development - laying roads, construction, operation of oil and gas fields, etc. Zonal features also determine the corresponding restrictions that must be observed in the territories being developed in order to maintain optimal environmental quality natural environment.[ ...]
Consequently, underground runoff into the seas with European continent also obeys the latitudinal physical-geographical zonality (Fig. 4.3.3). Local geological, hydrogeological and relief features of the catchment areas complicate this general pattern of runoff distribution and can sometimes cause their sharp deviations from typical average values. An example of such a determining influence of local factors on the conditions for the formation of underground runoff is the coastal regions of Scandinavia and the Mediterranean, where the screening effect of mountain structures, the widespread development of karst and fractured rocks lead to azonal high submarine runoff.[ ...]
The dependence of lake water mineralization on physical and geographical conditions, and especially on climate, determines the geographical zonality in the distribution of salt lakes over the earth's surface. In the Soviet Union, a strip of salt lakes stretches from the lower reaches of the Danube in the west to the Pacific Ocean in the east, located mainly in the zones of steppes, semi-deserts and deserts. In this strip there are large lakes - the Caspian Sea, Aral Sea, Lake. Balkhash and many small, sometimes temporary salt reservoirs. The northernmost position in this strip is occupied by carbonate lakes.[ ...]
The formation of meadow clearings in the place of green mosses with fresh, dryish soils is also strictly subordinated to geographical zonality; to the south they are replaced by reed grass and some other types.[ ...]
The publication of the work of V. V. Dokuchaev (Russia) "On the doctrine of the zones of nature", which formed the basis of modern ideas about geographical zonality.[ ...]
Since the most important soil-forming factor is the climate, then, to a large extent, genetic types soils coincide with geographical zonality: arctic and tundra soils, podzolic soils, chernozems, chestnut, gray-brown soils and gray, red and yellow soils. The distribution of the main types of soils on the globe is shown in fig. 6.6.[ ...]
The formation of meadow clearings, formed on the site of green mosses with fresh and dry soils, is also strictly subordinated to geographical zonality. To the south, they are replaced by reed grass, as well as some other types. It is impossible to overestimate the figures given in the table and give them absolute values for a long period. With the further development of logging and its wider coverage various types woods, numbers are subject to change. But geographical patterns in the distribution of felling types will remain, even more pronounced, in particular, in relation to swampy clearings, as well as other types.[ ...]
An analysis of the distribution of values of groundwater runoff into the seas and oceans from the territory of Africa shows that it also obeys the latitudinal physical and geographical zonality (Fig. 4.3.2).[ ...]
At the first stage of field work, reconnaissance is carried out along several shortened routes, which makes it possible to obtain information about the regularities of the geographical (zonal) distribution of the main soil types and the features of the structure of the soil cover as a whole. The accumulated information can be extrapolated during soil surveys to adjacent territories with similar soil formation conditions and similarly displayed on aerial and satellite images. After reconnaissance, research is carried out along all the planned routes, laying the main and verification sections. Samples are taken from the main sections according to genetic horizons for analytical processing. Between the points of laying the main sections along the route, inter-point descriptions of landforms, vegetation, soil-forming rocks and others are carried out. natural conditions.[ ...]
Lakes are very diverse in terms of the set and concentration of dissolved substances, and in this they are closer to groundwater than to the ocean. The mineralization of lakes is subject to geographical zonality: the Earth is surrounded by brackish and salty lakes, characteristic of arid and desert zones. Salt lakes are often endorheic, that is, they take in rivers, but from them water streams do not flow out, and the dissolved substances brought by the rivers gradually accumulate in the lake as a result of the evaporation of water from its surface. The water of some lakes is so saturated with salts that they crystallize, forming crusts of different shades on its surface or settling to the bottom. One of the saltiest lakes found in Antarctica is Lake Victoria, the water in which is 11 times saltier than the ocean.[ ...]
It was found that regional natural conditions determine many features of the regime of a small river. However, on the whole, its characteristics, and, consequently, its use and protection, are most closely related to geographic zoning, to the conditions of moisture that determine its water content - excessive, unstable, insufficient. The possibilities of using a small river (especially as a source of local water supply) differ significantly depending on whether it is located in the upper reaches of a large river basin, in its middle or lower part. In the first case small river actively forms the runoff, creates the water content of the main river arteries, therefore its use for local "small" irrigation, water withdrawal for industrial and agricultural water supply affect the water management balance major regions. Limitations were pointed out in determining the volumes of water taken from small rivers in upper parts basins of such rivers as the Dnieper, Oka, etc. On the contrary, active use runoff of small rivers in the lower part of a large river basin (for example, in Rostov region) is associated with less serious consequences for water management the river basin as a whole.[ ...]
On Earth, there are very clear patterns in the distribution of zones in space, with corresponding clear sets of natural features, such as the ratio of the components of thermal and water balances, zonal features of weathering processes rocks, biogeochemical processes, soils and vegetation. The existence of these features and their regular distribution reflect the geographic zonality of the Earth's landscapes.[ ...]
They are also subject to other natural phenomena, such as the main types of soils and geochemical processes, climate features, water balance and regime, many geomorphological processes, etc. This is the so-called law of geographical zoning, generalized by M.I. Budyko and A.A. Grigoriev.[ ...]
The qualitative and quantitative composition of the bird fauna of the northern part of the Urals characterizes it as typical of the taiga zone. natural character, the features of the distribution and promotion of species are quite consistent with the physical-geographical, zonal-latitudinal features and the transformation of landscapes on the plains adjacent to the Urals.[ ...]
A. Humboldt formulated the first ideas about the biosphere as an unification of all living organisms on the planet and environmental conditions. Lavoisier, in addition, gave a description of the carbon cycle, Lamarck - adaptations of organisms to environmental conditions, Humboldt - geographical zonality. Peru Lamarck owns the first warning predictions of the possible detrimental consequences of human influence on nature (see Alarmism). T. Malthus formulated ideas about the exponential growth of population and the danger of overpopulation. Huge contribution ecology was introduced by Ch. Darwin's ideas about natural and artificial selection, which explained the adaptability of wildlife species to various habitats and the loss of these features by cultivated plants and domestic animals.[ ...]
When carrying out a similar processing of data for 1990 and 1991. for 46 stations of the Middle and Lower Volga, using a larger number of abiotic parameters in high summer, four classes were more clearly distinguished, including from 7 to 10 stations and corresponding to the geographical zonality of the cascade (Table 31).[ ...]
In particular, the contribution of the "father of botany" Theophrastus, who formulated the first ideas about the life forms of plants and about geographical zonality, was especially great.[ ...]
The largest land communities, occupying large areas and characterized by a certain type of vegetation and climate, are called biomes. The type of biome is determined by climate. In different areas of the globe with the same climate, similar types of biomes are found: deserts, steppes, tropical and coniferous forests, tundra, etc. Biomes have a pronounced geographical zonality (Fig. 45, p. 142).[ ...]
For example, within the northern hemisphere, the following zones are distinguished: ice, tundra, forest-tundra, taiga, mixed forests of the Russian Plain, monsoon forests of the Far East, forest-steppe, steppe, desert temperate and subtropical zones, Mediterranean, etc. The zones have mainly (although far from 1 e always) broadly elongated outlines and are characterized by similar natural conditions, a certain sequence depending on the latitudinal position. Thus, latitudinal geographic zoning is a natural change in physical and geographical processes, components and complexes from the equator to the poles. It is clear that we are talking first of all, about the totality of factors that form the climate.[ ...]
EVOLUTION OF BIOGEOCOENOSIS (ECOSYSTEM) - the process of continuous, simultaneous and interrelated changes in species and their relationships, the introduction of new species into the ecosystem and the loss of some species that were previously included in it, the cumulative impact of the ecosystem on the substrate and other abiotic ecological components and the reverse effect of these changed components to the living components of the ecosystem. In the course of evolution, biogeocenoses adapt to changes in the planet's ecosphere and the emerging regional features of its parts (shifts in geographical zoning, etc.).
The doctrine of geographical zonality. Region in broad sense, as already noted, is a complex territorial complex, which is limited by specific homogeneity various conditions, including natural, geographical. This means that there is a regional differentiation of nature. The processes of spatial differentiation of the natural environment are greatly influenced by such a phenomenon as zonality and azonality of the geographic envelope of the Earth. By modern ideas, geographical zonality means a regular change in physical and geographical processes, complexes, components as you move from the equator to the poles. That is, zonality on land is a successive change of geographical zones from the equator to the poles and a regular distribution of natural zones within these zones (equatorial, subequatorial, tropical, subtropical, temperate, subarctic and subantarctic).
In recent years, with the humanization and sociologization of geography, geographical zones are increasingly being called natural-anthropogenic geographical zones.
The doctrine of geographical zoning has great importance for regional studies and country studies analysis. First of all, it allows you to reveal the natural prerequisites for specialization and management. And in the conditions of modern scientific and technological revolution, with a partial weakening of the dependence of the economy on natural conditions and natural resources, its close ties with nature continue to be preserved, and in many cases even dependence on it. The remaining important role of the natural component in the development and functioning of society, its territorial organization. Differences in the spiritual culture of the population also cannot be understood without referring to natural regionalization. It also forms the skills of adapting a person to the territory, determines the nature of nature management.
Geographic zonality actively influences regional differences in the life of society, being an important factor in zoning and, consequently, regional policy.
The doctrine of geographic zonality provides a wealth of material for country and regional comparisons and thus contributes to the clarification of country and regional specifics, its causes, which ultimately is the main task of regional studies and country studies. For example, the taiga zone in the form of a plume crosses the territories of Russia, Canada, and Fennoscandia. But the degree of population, economic development, living conditions in the taiga zones of the countries listed above have significant differences. In regional studies, country studies analysis, neither the question of the nature of these differences, nor the question of their sources can be ignored.
In a word, the task of regional studies and country studies analysis is not only to characterize the features of the natural component of a particular territory ( theoretical basis it is the doctrine of geographical zonality), but also the identification of the nature of the relationship between natural regionalism and the regionalization of the world in terms of economic, geopolitical, cultural, civilizational, etc. grounds.
Cycle method
cycle method. The basic basis of this method is the fact that almost all space-time structures are inherent in cyclicity. The method of cycles is among the young and therefore, as a rule, it is personified, that is, it bears the names of its creators. This method has an undoubted positive potential for regional studies. Identified by N.N. Kolosovsky, energy production cycles, unfolding in certain territories, made it possible to trace the regional specifics of their interaction. And she, in turn, was projected onto certain management decisions, i.e. to regional politics.
The concept of ethnogenesis L.N. Gumilyov, also based on the method of cycles, allows you to penetrate deeper into the essence of regional ethnic processes.
The concept of large cycles, or "long waves" N.D. Kondratiev is not only a tool for analyzing the current state of the world economy, but also has a great predictive charge not only in relation to the development of the world economy as a whole, but also its regional subsystems.
Models of cyclical geopolitical development (I. Wallerstein, P. Taylor, W. Thompson, J. Modelski and others) explore the process of transition from one “world order” to another, changes in the balance of power between great powers, the emergence of new conflict zones, centers of power . Thus, all these models are important in studying the processes of political regionalization of the world.
20. Program-target method. This method is a way of studying regional systems, their socio-economic component and, at the same time, an important tool of regional policy. Examples of targeted comprehensive programs in Russia are the presidential program "Economic and social development of the Far East and Transbaikalia for 1996-2005", " federal program development of the Lower Angara region”, adopted in 1999, etc.
The program-target method is aimed at solving difficult problems, is associated with the development of long-term forecasts of social economic development country and its regions.
The program-target method is actively used to solve the problems of regional policy in most countries of the world. In Italy, within the framework of regional policy, in 1957 the first law on "growth poles" was adopted. In accordance with it, in the south of Italy (this is a region with a strong lag behind industrial developed North) were built several large enterprises, for example, a metallurgical plant in Taranta. Growth poles are being created in France and Spain. The core of Japan's regional programs is the target setting for the development of infrastructure associated with an increase in exports.
Development and implementation of targeted programs - a characteristic feature of politics European Union. An example of such, for example, are the programs "Lingua", "Erasmus". The purpose of the first one is to eliminate language barrier, the second is the expansion of the exchange of students between the countries of the Union. In 1994–1999 within the framework of the EU, 13 targeted programs were financed - "Leader II" (social development of the countryside), "Urban" (liquidation of urban slums), "Reshar II" (coal industry), etc.
Similar information.
Many physical-geographical phenomena in the geographic envelope are distributed in the form of strips elongated along the parallels, or at some angle to them. This property of geographical phenomena is called zonality (the law of geographical zonality).
Ideas about natural zonality arose even among ancient Greek scientists. So, in the 5th c. BC. and Eudoniks noted five zones of the Earth: tropical, two temperate and two polar. Huge contribution the doctrine of natural zonality was introduced by the German geographer, who established the climatic and vegetative zones of the Earth ("Geography of Plants", 1836). In Russia, ideas about geographical zonality were expressed in 1899 in the book “The Doctrine of Natural Zones. Horizontal and vertical soil zones". The professor owns research on the causes and factors of zoning. He came to the conclusion about the great role of the ratio of the radiation balance and the amount of annual precipitation (1966).
It is currently believed that natural zoning is represented by
- component zoning;
- landscape zoning.
All components geographical envelope are subject to the World law of zoning. Zoning is noted for climate indicators, plant groups and soil types. It also manifests itself in hydrological and geochemical phenomena, as a derivative of climatic and soil and plant conditions.
The basis of the zonality of physical and geographical phenomena is the regularity of the influx of solar radiation, the influx of which decreases from the equator to the poles. However, this distribution of solar radiation is superimposed by the transparency factor of the atmosphere, which is azonal, since it is not related to the shape of the Earth. The air temperature depends on solar radiation, the distribution of which is influenced by another azonal factor - the properties of the earth's surface - its heat capacity and thermal conductivity. This factor leads to even greater violation of zoning. The distribution of heat on the Earth's surface is also greatly influenced by ocean and air currents, which form heat transfer systems.
Precipitation is even more difficult to distribute on our planet. On the one hand, they have a zonal character, and on the other hand, they are associated with the position of the territory in the western or eastern part of the continents and the height of the earth's surface.
The combined effect of heat and moisture is the main factor that determines most physical and geographical phenomena. Since the distribution of moisture and heat is oriented along latitude, then all the phenomena associated with climate are oriented latitude. As a result, a latitudinal structure is formed on the Earth, called geographic zonality.
Clarification is manifested in the distribution of the main climatic characteristics: solar radiation, temperature and atmospheric pressure, which leads to the formation of a system of 13 climatic zones. Plant groups on Earth also form elongated bands, but more complex configuration than climatic zones. They are called vegetation zones. The soil cover is closely related to vegetation, climate, and the nature of the relief, which allowed V.V. Dokuchaev to identify the genetic types of soils.
In the 1950s, geographers Grigoriev and Budyko developed Dokuchaev's zoning law and formulated periodic law of geographic zoning. This law establishes the repetition of the same type of geographical zones within the belts - depending on the ratio of heat and moisture. Thus, there are forest zones in the equatorial, subequatorial, tropical and temperate zones. Steppes and deserts are also found in different geographical zones. The presence of zones of the same type in different belts is explained by the repetition of the same ratios of heat and moisture.
In this way, zone- this is large part geographic zone, which is characterized by the same indicators of the radiation balance, annual precipitation and evaporation. At the beginning of the last century, Vysotsky proposed a moisture coefficient, equal to the ratio precipitation to evaporation. Later, Budyko, to substantiate the periodic law, introduced an indicator - the radiation index of dryness, which is the ratio of the incoming amount of solar energy to the heat spent on the evaporation of precipitation. It has been established that there is a close relationship between geographical zones and the amount of solar heat input and the radiation index of dryness.
Geographical zones are internally heterogeneous, which is primarily due to the azonal circulation of the atmosphere and moisture transport. With this in mind, sectors are allocated. As a rule, there are three of them: two oceanic (western and eastern) and one continental. Sector – this is a geographical zonality, which is expressed in a change in the main natural indicators in longitude, that is, from the oceans deep into the continents.
Landscape zoning is determined by the fact that the geographic shell in the process of its development has acquired a "mosaic" structure and consists of many natural complexes of unequal size and complexity. By definition, F.N. Milkov PTC is a self-regulating system of interconnected components, functioning under the influence of one or more components acting as a leading factor.
This is one of the main regularities of the geographic shell of the Earth. It manifests itself in a certain change in the natural complexes of geographical zones and all components from the poles to the equator. The basis of zoning is the different supply of heat and light to the earth's surface, depending on the geographical latitude. Climatic factors affect all other components and, above all, soils, vegetation, and wildlife.
The largest zonal latitudinal physiographic subdivision of the geographic shell is the geographic belt. It is characterized by the generality of (temperature) conditions. The next step in the division of the earth's surface is the geographical zone. It stands out within the belt not only by the commonality of thermal conditions, but also by moisture, which leads to a commonality of vegetation, soils and other biological components of the landscape. Within the zone, subzones-transitional areas are distinguished, which are characterized by the mutual penetration of landscapes. They are formed as a result of gradual change climatic conditions. For example, in the northern taiga, tundra areas (forest tundra) are found in forest communities. Subzones within zones are distinguished by the predominance of landscapes of one type or another. So, in the steppe zone, two subzones are distinguished: northern steppe on black soils and southern steppe on dark chestnut soils.
Let's briefly get acquainted with the geographical zones of the globe in the direction from north to south.
Ice zone, or zone of arctic deserts. Ice and snow persist almost all year round. In the warmest month - August, the air temperature is close to 0°С. Spaces free from glaciers are bound by permafrost. Intense frosty weathering. Placers of coarse clastic material are widespread. Soils are underdeveloped, stony, of low thickness. Vegetation covers no more than half of the surface. Mosses, lichens, algae and a few flowering species (polar poppy, buttercup, saxifrage, etc.) grow. Of the animals found lemmings, arctic fox, polar bear. In Greenland, in the north of Canada and Taimyr - a musk ox. Bird colonies nest on the rocky coasts.
Tundra zone of the subarctic belt of the Earth. Summer is cold with frosts. The temperature of the warmest month (July) in the south of the zone is +10°, +12°С, in the north +5°С. There are almost no warm days with an average daily temperature above + 15°C. There is little precipitation - 200-400 mm per year, but due to low evaporation, moisture is excessive. Almost ubiquitous permafrost; high wind speeds. The rivers are full of water in summer. The soils are thin, there are many swamps. The treeless expanses of the tundra are covered with mosses, lichens, grasses, dwarf shrubs and undersized creeping shrubs.
The tundra is inhabited by reindeer, lemmings, arctic foxes, ptarmigan; in summer there are many migratory birds - geese, ducks, waders, etc. In the tundra zone, subzones of moss-lichen, shrubs and others are distinguished.
The forest zone of the temperate climate zone with a predominance of coniferous and summer-green deciduous forests. Cold snowy winter and warm summer, excessive moisture; the soil is podzolic and swampy. Meadows and swamps are widely developed. In modern science, the forest zone of the northern hemisphere is divided into three independent zones: taiga, mixed forests and the zone of deciduous forests.
The taiga zone is formed by both pure coniferous and mixed species. In the dark coniferous taiga, spruce and fir predominate, in the light coniferous taiga - larch, pine, and cedar. They are mixed with narrow-leaved trees, usually birch. The soils are podzolic. Cool and warm summers, severe, long winters with snow cover. The average temperature in July in the north is +12°, in the south of the zone -20°C. January from -10°С in the west of Eurasia to -50°С in Eastern Siberia. Precipitation is 300-600 mm, but this is higher than the evaporation value (except for the south of Yakutia). Great morbidity. Forests are uniform in composition: dark spruce forests predominate on the western and eastern outskirts of the zone. In areas with a sharply continental climate (Siberia) - light larch forests.
The zone of mixed forests is coniferous-deciduous forests on soddy-podzolic soils. The climate is warmer and less continental than in the taiga. Winter with snow cover, but without severe frosts. Precipitation 500-700 mm. In the Far East, the climate is monsoonal with annual precipitation up to 1000 mm. The forests of Asia and North America are richer in vegetation than in Europe.
The broad-leaved forest zone is located in the south of the temperate zone along the humid (precipitation 600-1500 mm per year) margins of the continents with their marine or temperate continental climate. This area is especially widespread in Western Europe where several species of oak, hornbeam, chestnut grow. The soils are brown forest, gray forest and sod-podzolic. In the Russian Federation, such forests in their pure form grow only in the very south-west, in the Carpathians.
Steppe zones are common in temperate and subtropical zones of both hemispheres. Currently heavily plowed. The temperate zone is characterized by a continental climate; precipitation - 240-450 mm. Average July temperatures are 21-23°C. Winter is cold with thin snow cover and strong winds. Predominantly grassy vegetation on chernozem and chestnut soils.
The transition zones between the zones are forest-tundra, forest-steppe and semi-desert. On their territory dominates, as in the main zones, their own, zonal type of landscape, which is characterized by alternation of sites, for example: forest and steppe vegetation - in the forest-steppe zone; woodlands with typical tundra - in the lowlands - for the forest-tundra subzone. In the same way, other components of nature-soil alternate, animal world and others. Significant differences are also observed throughout these zones. For example, the Eastern European forest-steppe is oak, the Western Siberian is birch, the Daurian-Mongolian is birch-pine-larch. The forest-steppe is also widespread in Western Europe (Hungary) and North America.
In the temperate, subtropical and tropical zones are desert geographical zones. They are distinguished by arid and continental climate, sparse vegetation and salinity of soils. The annual amount of precipitation is less than 200 mm, and in super-arid regions it is less than 50 mm. In the formation of the relief of desert zones, the leading role belongs to weathering and wind activity (eolian landforms).
Desert vegetation is drought-resistant shrubs (wormwood, saxaul) with long roots, which allow you to collect moisture from large areas and lush-flowering ephemera in early spring. Ephemera - plants that develop (bloom and bear fruit) in the spring, that is, in the wettest time of the year. Usually it lasts no more than 5-7 weeks.
Semishrubs are able to tolerate overheating and dehydration, even with water losses of up to 20-60%. Their leaves are small, narrow, sometimes turning into spines; in some plants, the leaves are pubescent or covered with a wax coating, in others - succulent stems or leaves (cacti, agaves, aloe). All this helps plants to tolerate drought well. Among animals, rodents and reptiles predominate everywhere.
In subtropical zones, the temperature of the coldest month is not less than -4°C. Moisture varies by season: the wettest is winter. In the western sector of the continents, there is a zone of evergreen hardwood forests and shrubs of the Mediterranean type. They grow in northern and southern hemispheres approximately between 30° and 40° latitude. In the inland parts of the northern hemisphere, deserts stretch, and in the eastern sectors of the continents with a monsoon climate and heavy summer precipitation - deciduous forests (beech, oak) with an admixture of evergreen species, under which yellow and red soils are formed.
tropical belts located approximately between 20 and 30 ° N. and yu. sh. Their main features are: arid conditions, high air temperatures on land, anticyclones dominated by trade winds, low cloudiness and light precipitation. Semi-deserts and deserts predominate, they are replaced in the more humid eastern outskirts of the continents by savannahs, dry forests and light forests, and in more favorable conditions and wet tropical forests. The most pronounced zone is the savanna-tropical type of vegetation, combining grassy grass cover with single trees and shrubs. Plants are adapted to endure prolonged drought: the leaves are hard, strongly pubescent or in the form of thorns, the bark of the trees is thick.
The trees are stunted, with gnarled trunks and an umbrella-shaped crown; some trees store moisture in their trunks (baobab, bottle tree, etc.). Of the animals, large herbivores are found - elephants, rhinos, giraffes, zebras, antelopes, etc.
Many physical-geographical phenomena in the geographic envelope are distributed in the form of strips elongated along the parallels, or at some angle to them. This property of geographical phenomena is called zonality (the law of geographical zonality). Ideas about natural zonality arose even among ancient Greek scientists. So, in the 5th c. BC. Herodotus and Eudoniks noted five zones of the Earth: tropical, two temperate and two polar. A great contribution to the doctrine of natural zoning was made by the German geographer Humboldt, who established the climatic and vegetative zones of the Earth ("Geography of Plants", 1836). In Russia, ideas about geographical zonality were expressed in 1899 by Dokuchaev in the book “The Teaching about Natural Zones. Horizontal and vertical soil zones". Professor Grigoriev owns research on the causes and factors of zoning. He came to the conclusion about the great role of the ratio of the radiation balance and the amount of annual precipitation (1966).
It is currently believed that natural zoning is represented by
component zoning;
landscape zoning.
All components of the geographical envelope are subject to the World law of zoning. Zoning is noted for climatic indicators, plant groups and soil types. It also manifests itself in hydrological and geochemical phenomena, as a derivative of climatic and soil and plant conditions.
The basis of the zonality of physical and geographical phenomena is the regularity of the influx of solar radiation, the influx of which decreases from the equator to the poles. However, this distribution of solar radiation is superimposed by the transparency factor of the atmosphere, which is azonal, since it is not related to the shape of the Earth. The air temperature depends on solar radiation, the distribution of which is influenced by another azonal factor - the properties of the earth's surface - its heat capacity and thermal conductivity. This factor leads to even greater violation of zoning. The distribution of heat on the Earth's surface is also greatly influenced by ocean and air currents, which form heat transfer systems.
Precipitation is even more difficult to distribute on our planet. On the one hand, they have a zonal character, and on the other hand, they are associated with the position of the territory in the western or eastern part of the continents and the height of the earth's surface.
The combined effect of heat and moisture is the main factor that determines most physical and geographical phenomena. Since the distribution of moisture and heat is oriented along latitude, then all the phenomena associated with climate are oriented latitude. As a result, a latitudinal structure is formed on the Earth, called geographic zonation.
The zonation is manifested in the distribution of the main climatic characteristics: solar radiation, temperature and atmospheric pressure, which leads to the formation of a system of 13 climatic zones. Plant groups on Earth also form elongated bands, but of a more complex configuration than climatic zones. They are called vegetation zones. The soil cover is closely related to vegetation, climate, and the nature of the relief, which allowed V.V. Dokuchaev to identify the genetic types of soils.
In the 1950s, the geographers Grigoriev and Budyko developed Dokuchaev's zoning law and formulated the periodic law of geographical zoning. This law establishes the repetition of the same type of geographical zones within the belts - depending on the ratio of heat and moisture. Thus, there are forest zones in the equatorial, subequatorial, tropical and temperate zones. Steppes and deserts are also found in different geographical zones. The presence of zones of the same type in different belts is explained by the repetition of the same ratios of heat and moisture.
Thus, the zone is a large part of the geographical zone, which is characterized by the same indicators of the radiation balance, annual precipitation and evaporation. At the beginning of the last century, Vysotsky proposed a moisture coefficient equal to the ratio of precipitation to evaporation. Later, Budyko, to substantiate the periodic law, introduced an indicator - the radiation index of dryness, which is the ratio of the incoming amount of solar energy to the heat spent on the evaporation of precipitation. It has been established that there is a close relationship between geographical zones and the amount of solar heat input and the radiation index of dryness.
Geographical zones are internally heterogeneous, which is primarily due to the azonal circulation of the atmosphere and moisture transfer. With this in mind, sectors are allocated. As a rule, there are three of them: two oceanic (western and eastern) and one continental. Sectorization is a geographical zonality, which is expressed in a change in the main natural indicators in longitude, that is, from the oceans deep into the continents.
Landscape zoning is determined by the fact that the geographic shell in the process of its development has acquired a "mosaic" structure and consists of many natural complexes of unequal size and complexity. By definition, F.N. Milkov PTK is a self-regulating system of interconnected components, functioning under the influence of one or more components acting as a leading factor.
Vertical zonation
Altitudinal zonality - part of the vertical zonality of natural phenomena and processes related only to mountains. Due to the regular decrease in air temperatures with height, the ratios of heat and moisture, runoff conditions, relief formation, soil and vegetation cover and animals associated with it change.
Climbing a high mountain is accompanied by a change in several belts of vegetation, as when moving from the equator to the poles. Unlike natural areas, there are few animals here, but many birds of prey (the largest bird of prey is the condor. It soars over the Andes at an altitude of up to 7 thousand meters). In every type environment there is its own community of animals and plants even within the same natural zone, but on different continents (natural complex). Simultaneously with zonal factors, there are also azonal factors associated with the internal energy of the Earth (relief, height, configuration of continents).
In any part of the world, zonal and azonal factors act simultaneously. The set of altitudinal belts in the mountains depends on the geographical position of the mountains themselves, which determines the nature of the lower belt, and the height of the mountains, which determines the nature of the upper tier. The sequence of altitudinal belts coincides with the sequence of changes in natural zones on the plains. But in the mountains, the belts change faster, there are belts that are typical only for the mountains - subalpine and alpine meadows.
Altitudinal zonality mountain systems diverse. It is closely related to latitudinal zones. Climate, soil and vegetation cover, hydrological and geomorphological processes are transformed with height, the exposure factor of slopes comes out sharply, etc. With a change in the components of nature, natural complexes change - high-altitude natural belts are formed. The phenomenon of changing natural-territorial complexes with height is called altitudinal zonality, or vertical altitudinal zonality.
The formation of types of altitudinal zonality of mountain systems is determined by the following factors:
- > Geographical position mountain system. The number of mountain high-altitude belts in each mountain system and their altitudinal position in the main features are determined by the latitude of the place and the position of the territory in relation to the seas and oceans. As you move from north to south, the altitude position natural belts in the mountains and their set is gradually increasing.
- > The absolute height of the mountain system. The higher the mountains rise and the closer they are to the equator, the more altitudinal belts they have. Therefore, each mountain system develops its own set of altitudinal belts.
- > Relief. The relief of mountain systems (orographic pattern, degree of dissection and evenness) determines the distribution of snow cover, moistening conditions, the preservation or removal of weathering products, affects the development of soil and vegetation cover, and thereby determines the diversity of natural complexes in the mountains. For example, the development of leveling surfaces contributes to an increase in the areas of altitudinal belts and the formation of more homogeneous natural complexes.
- > Climate. This is one of the most important factors that form the altitudinal zonality. As you climb into the mountains, temperature, humidity, solar radiation, wind direction and strength, and weather types change. The climate determines the nature and distribution of soils, vegetation, wildlife, etc., and, consequently, the diversity of natural complexes.
slope exposure. It plays a significant role in the distribution of heat, moisture, wind activity, and, consequently, the processes of weathering and the distribution of soil and vegetation cover. On the northern slopes of each mountain system, the altitudinal belts are usually located lower than on the southern slopes.
The position, change of boundaries and the natural appearance of altitudinal zones are also influenced by economic activity person.
Already in the Neogene, on the plains of Russia, there were latitudinal zones almost similar to modern ones, but due to the warmer climate, the zones of arctic deserts and tundra were absent. In the Neogene-Quaternary time, significant changes in natural zones occur. This was caused by active and differentiated neotectonic movements, climate cooling and the emergence of glaciers on the plains and mountains. Therefore, the natural zones shifted to the south, the composition of their flora changed (increased deciduous boreal and cold-resistant flora of modern coniferous forests) and fauna, the youngest zones formed - tundra and arctic desert, and in the mountains - alpine, mountain-tundra and nival-glacial belts.
During the warmer Mikulin interglacial period (between the Moscow and Valdai glaciations), the natural zones shifted to the north, and the altitudinal belts occupied more than high levels. At this time, the structure of modern natural zones and altitudinal belts was formed. But due to climate change in the late Pleistocene and Holocene, the boundaries of zones and belts shifted several times. This is confirmed by numerous relict botanical and soil finds, as well as spore-pollen analyzes of Quaternary deposits.
In the mountains, when climbing up, the amount and composition of solar radiation changes, the amount of precipitation decreases and Atmosphere pressure. A change in climatic conditions leads to a change in the same direction of geomorphological processes, the composition of vegetation, soil characteristics and the nature of the animal world. This makes it possible to single out vertical belts in mountain systems.
Vertical belts are similar to horizontal zones in the sense that they change when moving upward in approximately the same order (starting from the latitudinal zone in which the mountainous country is located) in which latitudinal zones change when moving from the equator to the poles. But vertical belts are not exact copies similar latitudinal zones, since they are influenced by local conditions (the dissection of the relief, the difference in slope exposures, the height of the mountains, the history of the development of the area, etc.).
Despite some similarities of vertical zonality in different mountain systems, the latter manifests itself differently on different continents and geographical latitudes. The degree of severity of vertical zonality, i.e., the number of vertical belts, their height, continuity of extension, floristic and faunal composition depend on the position of the mountain system, its latitude, the direction of the ridges, the degree of dissection, the history of formation, and some other reasons.
We will demonstrate this using the example of two mountain systems ( Verkhoyansk Range and Greater Caucasus).
a) Verkhoyansk Range, or rather whole system ridges, in size several times larger than the system of ridges of the Greater Caucasus. Despite this, the Verkhoyansk Range has a less diverse nature, i.e., a smaller number of vertical belts are expressed within it than in the Greater Caucasus, and similar belts of these mountain systems differ sharply in the nature of vegetation, soils and wildlife.
The Verkhoyansk Range is located in the temperate zone, in the taiga zone, in the northeast of Siberia. The climate here is very severe. Near the ridge is the "pole of cold"; the ground is covered with permafrost all year round; piercing winds blow; the amount of precipitation is negligible (200--300 mm per year).
The slopes of the ridge from the base to a height of about 1 thousand m are covered with taiga, in the northern part of the sparse, consisting of Daurian larch (Larix dahurica). The latter is adapted to living in the most harsh conditions, on frozen ground. Podzolic soils are developed under the taiga. The taiga belt is replaced by a belt of subalpine shrubs (on podzolic soils), the most widespread of which is Siberian dwarf pine (Pinus pumila), a creeping species of cedar pine. Above 1000-1500 m, the bald belt begins, i.e., mountain lichen-rubble tundra with reindeer moss (Cladonia), partridge grass (Dryas punctata), cinquefoil (Potentilla nivea), etc. Such is the meager vegetation of the Verkhoyansk Range.
b) The Greater Caucasus is located on the border of the temperate and subtropical climatic zones. This alone suggests a variety of natural conditions in the Greater Caucasus in the form of a significant number of vertical belts and their differences on the northern and southern slopes. In addition, the vertical zonality is complicated here by the increase in dryness from west to east. All these factors greatly diversify the vertical zonality in the Greater Caucasus and lead to its differences on the northern and southern slopes, as well as in the west and east.
When climbing the mountains from the side of the Rion lowland, we will meet the following vertical belts:
- 1. Belt of relict Colchis forests, developed mainly on podzolic-yellow earth soils. The basis of the forest here is made up of broad-leaved species: Hartvis oak (Quercus hartwissiana), Georgian oak (Quercus iberica), noble chestnut (Castanea satwa), oriental beech (Fagus orientalis), hornbeam (Carpinus caucasica). Evergreen shrubs are developed in the undergrowth: Pontic rhododendron ( Rhododendron ponticum), laurel (Laurus nobiles), etc.
- 2. From a height of 600 m to a height of about 1200 m stretches a belt of beech forests (dark and damp), consisting mainly of oriental beech, which is joined by other broad-leaved species. In this belt, mountain forest brown soils are developed.
- 3. Even higher stretches the belt of coniferous and coniferous-deciduous forests, consisting of Caucasian spruce (Picea orientalis), Caucasian fir. (Abies nordmanniana) and oriental beech; mountain-podzolic and mountain-forest brown soils are developed under them.
- 4. From a height of about 2000 m, the subalpine belt begins - tall grass meadows and thickets of the Caucasian rhododendron (Rhododendron caucasicum) on mountain meadow soils. The alpine belt stretches even higher, where alpine meadows, developed on mountain meadow soils, alternate with almost bare rocks and talus. And, finally, the last is the nival belt - the area of \u200b\u200bdistribution of eternal snows and glaciers.
The northern slope of the Western Caucasus differs from the southern slope in the absence of a belt of Colchian forests, which here is replaced by a belt of oak forests, consisting mainly of oak (Quercus petraca). The rest of the vertical belts are somewhat different from the above in their floristic composition.
A completely different character of vertical zonality is observed in the Eastern Caucasus. At the foot of the slope there are deserts and semi-deserts of the Kura lowland on gray, brown and chestnut soils, deserts and semi-deserts on extreme east climb the mountains to a height of 800 m. Their main representative is Hansen's wormwood (Artemisia Hanseniana). Above is a belt of steppes, on mountain chernozems and dark chestnut soils, which gradually wedges out when moving west.
Above (on average at an altitude of 500-1200 m) there is a belt of oak forests with an admixture of other broad-leaved species (Georgian oak, Caucasian hornbeam) on brown soils. Where the forests have been cut down, upland xerophyte vegetation (shublyak) is widely developed, consisting mainly of the steer tree (Paliurus spina).
At an altitude of 1200-2000 m stretches a belt of beech and beech-hornbeam forests, which at the upper border of the forest are replaced by thickets of oriental oak (Quercus macranthera). There are no coniferous forests in the Eastern Caucasus. The soils are brown forest.
At an altitude of 2000-2500 m, subalpine meadows are developed, which differ from those of the Western Caucasus in their strong steppe formation and low herbage (high-mountain steppes). Above, they pass into alpine meadows. The soils are mountainous. And finally on maximum heights the nival belt is developed, which has a slight distribution in the Eastern Caucasus.
The northern slope of the Eastern Caucasus (including Dagestan) is distinguished by the absence of deserts at the foot, the greater xerophyte content of high-mountain meadows (high-mountain steppes on mountain meadow-steppe soils) and great development upland xerophytic vegetation.
