home » Shoes » Natural zoning. The doctrine of geographical zonation How does the law of nature manifest itself?

Natural zoning. The doctrine of geographical zonation How does the law of nature manifest itself?

LAW OF ZONING

LAW OF ZONALITY formulated by V.V. Dokuchaev (1898) is a regularity in the structure of the geosphere, manifested in the ordered arrangement of geographical zones on land and geographical zones in the ocean.

Ecological encyclopedic dictionary. - Chisinau: Main editorial office of the Moldavian Soviet Encyclopedia. I.I. Dedu. 1989.

LAW OF NATURAL HISTORY
LAW OF HISTORICAL DEVELOPMENT OF BIOLOGICAL SYSTEMS

See what the “LAW OF ZONING” is in other dictionaries:

- (otherwise the law of azonality, or provinciality, or meridionality) the pattern of differentiation of the Earth’s vegetation cover under the influence of the following reasons: the distribution of land and sea, the topography of the earth’s surface and the composition of mountains ... Wikipedia

LAW OF VERTICAL ZONING- see Vertical zonation of vegetation. Ecological encyclopedic dictionary. Chisinau: Main editorial office of the Moldavian Soviet Encyclopedia. I.I. Dedu. 1989 ... Ecological dictionary

Natural land zones, large divisions of the geographical (landscape) shell of the Earth, regularly and in a certain order replacing each other depending on climatic factors, mainly on the ratio of heat and moisture. IN… … Great Soviet Encyclopedia

Wikipedia has articles about other people with this surname, see Dokuchaev. Vasily Vasilyevich Dokuchaev Date of birth: March 1, 1846 (1846 03 01) Place of birth ... Wikipedia

- (March 1, 1846 November 8, 1903) famous geologist and soil scientist, founder of the Russian school of soil science and soil geography. He created the doctrine of soil as a special natural body, discovered the basic laws of the genesis and geographical location of soils.... ... Wikipedia

Vasily Vasilyevich Dokuchaev Vasily Vasilyevich Dokuchaev (March 1, 1846 November 8, 1903) famous geologist and soil scientist, founder of the Russian school of soil science and soil geography. He created the doctrine of soil as a special natural body, discovered the main... ... Wikipedia

The presented factual material of the previous chapters allows us to draw general conclusions about the characteristic features of the geographic shell as a whole and its patterns, which are a consequence of the interpenetration and interaction of the earth's crust, lower atmosphere, hydrosphere, vegetation, soils and fauna.

The geographical envelope has a certain structure. It is expressed in the phenomenon zoning, V.V. Dokuchaev created the doctrine of natural zones, in which zonality was interpreted as world law. Dokuchaev expressed the idea that each natural zone (tundra, forest zone, steppe, desert, savannah, etc.) represents a regular natural complex in which living and inanimate nature are closely connected and interdependent. Based on the teaching, the first classification of natural zones was created, which was subsequently deepened and specified by L. S. Berg.

The forms of manifestation of zonality are different. They acquire specific features due to the complex structure and diversity of the material composition of the geographical envelope. This is confirmed by the zonality of various natural components, such as climate, geochemical processes, distribution of the main life forms of plants, soils, etc.

The phenomenon of zoning is due to the influence of two main factors of planetary-cosmic order: the radiant energy of the Sun and the internal energy of the Earth. Associated with them is the manifestation of general patterns of territorial differentiation of the geographical envelope: zonality and regionality(azonality), which appear together. The distribution of the oceans, the variety of land surface topography, and the complexity of its geological structure violate the “ideal” zonation scheme. Different parts of the geographic envelope acquire individual features, which complicates its structure. This phenomenon should be understood as regionality.

As a result of the unequal development of various areas within the geographical envelope, many natural complexes of varying complexity and size, which represent systems of subordinate natural units of different ranks.

The largest latitudinal-zonal division of the geographic envelope is the geographic zone. It is distinguished on the basis of differences in the main types of radiation balance and the nature of the general circulation of the atmosphere and is close in its position to the climatic zones of B.P. Alisov. The relative uniformity of the climate within the belt is reflected in other components, such as vegetation, soils, fauna, etc.

The following geographical zones are distinguished on the globe: one equatorial, two subequatorial, two tropical, two subtropical, two temperate, two subpolar and two polar - Arctic and Antarctic (Fig. 83).

What is a geographical zone?

The belt does not have the correct ring shape. It can expand and contract under the influence of topography (continent) or sea currents (ocean). The belt is most homogeneous over the ocean. On continents, within the belts, sectors are distinguished that differ in the degree of moisture. The greatest contrasts are found in the inland, western oceanic and eastern oceanic sectors. Often the boundaries of sectors coincide with orographic boundaries (Cordillera, Andes).

Geographic zones are divided into zones. The formation of zones occurs due to the uneven distribution of heat and moisture on the Earth's surface. Zones with the same ratio of heat and moisture are repeated to a certain extent in each zone and their boundaries are associated with certain values of the radiation balance and radiation dryness index to the earth's surface. The last indicator is determined from the formula

Where R - annual radiation balance of the underlying surface, r - annual precipitation over the same area, L - latent heat of evaporation.

From the table below. Figure 6 shows that the repetition of types of geographical zones in each zone depends on the repetition of certain values TO.

The distribution of geographical zones and zones on the earth's surface is shown on the map (see Fig. 83). Relationship between zone boundaries and values TO it is possible to explain the violations of geographic zonality visible on the map, for example, pinching out of zones, their rupture, deviation from the latitudinal strike. The zones can acquire a direction close to the meridional (North America). The dependence of the development of certain zones in

coastal sectors of the belts (zone of mixed and broad-leaved forests), others - in inland sectors (forest-steppe and steppe zones).

The position of zonal boundaries is determined not only by climatic factors, but also by azonal ones (relief, geological structure). Their influence is manifested in the process of historical development of the entire geographical envelope. The influence of orography is especially great. In the mountains of each geographic zone, a certain type of vertical zonality is formed, which is associated with vertical belts of vegetation and soils. Each zone is characterized by a strictly defined set of belts, changing in height in a sequence similar to some extent to the location of latitudinal geographic zones. Originality

altitudinal zones as special natural complexes is expressed not only in the features of their climate, but also in a number of other phenomena: the intensity of weathering processes, the nature of rivers, mountain glaciers, and soil formation features. Some altitudinal zones, for example alpine meadows and high-mountain deserts, have no analogues among latitudinal zones. The nature of altitudinal zonation in the mountains and its severity depending on the position in the geographical zones are shown in Fig. 83 and 84.

Geographic zones are divided into subzones. In soil and geobotanical terms, the subzones are characterized by the predominance of zonal subtypes of soils and plant formations. This physical-geographical unit is most clearly expressed in zones of large north-south extent: the tundra zone of Eurasia, the taiga zone, the tropical savanna, etc. It must be borne in mind that the subzones do not always coincide with the boundaries of the soil and plant subzones. Geobotanists do not distinguish, for example, subzones of forest-steppe and semi-desert, since such types of vegetation do not exist.

Consideration of the issue of natural zoning is not only theoretical, but also practical in connection with the analysis of natural processes caused by the intensive use of natural resources. Based on heat balance calculations, it becomes possible to determine rational irrigation rates and assess its impact on the climate regime. The reclamation direction of nature transformation represents a higher level of knowledge of geographical phenomena. Rational integrated use of natural resources involves constructive transformation of nature. An example of this is solving the problem of regulating the level of the Caspian Sea, irrigating the deserts of Central Asia, developing the oil and gas and forest resources of Western Siberia, etc.

- Source-

Bogomolov, L.A. General Geography / L.A. Bogomolov [and others]. – M.: Nedra, 1971.- 232 p.

Post Views: 1,729

1. How does the law of natural zonality manifest itself on the territory of Eurasia?

This geographical law on the territory of Eurasia is most clearly manifested in the sequence of alternation of natural zones. One natural zone replaces another when moving from north to south.

2. It is known that more plant mass is formed in forests than in steppes, but chernozem soils are much more fertile than podzolic soils. How can we explain this?

Each natural zone has its own geographical features, type of vegetation, soil, etc. Forest soils, despite the large amount of biomass, are less fertile than steppe soils, which is associated with the processes of their formation. In coniferous forests the soils are podzolic. Organic substances do not accumulate, but are washed away by melt and rainwater. In the steppes, they linger in the upper layers of the soil. This is how fertile chernozems are formed, on which good crops are grown without additional addition of minerals and soil reclamation.

3. Which natural zones of the temperate zone are most developed by humans? What contributed to their development?

The forest-steppe and steppe zones are the most developed by humans.

People need bread. Rye and wheat produce greater yields in the steppe and forest-steppe, since the soil there is better than in the forest zone. This was the impetus for the development of agriculture in these zones. Livestock farming is predominantly developed in the forest zone.

4. On which continent do tropical deserts occupy the largest areas? Indicate the reasons for their spread.

Tropical deserts are the most unfavorable for human habitation and economic activity. They occupy mainly the territory of South-West Asia, as if continuing the huge tropical desert of Africa, the Sahara. The reason for the spread of tropical deserts is climatic conditions: very little precipitation, as well as high temperatures, which increase the evaporation of the already low humidity and contribute to the creation of a dry and hot climate in the area of tropical deserts. The desert area is gradually increasing. This is due both to the general trend towards climate warming and, to a greater extent, to the mismanagement of the population living on the borders of tropical deserts. The main type of economy in desert areas is sheep breeding. Desert vegetation inhibits the movement of sands. Mechanical disturbance of the top layer of soil by herds of sheep and goats leads to intensive sand blowing and movement. The process of expanding the desert zone is called desertification. This process annually reduces the areas of land suitable for human life. These areas become barren deserts covered with shifting sands.

5. Using the example of one of the natural zones of Eurasia, show the connections between the components of its nature.Material from the site

Natural components within the natural zone are closely interconnected. The humid and warm climate of equatorial forests contributes to the intensive development of vegetation, which, in turn, provides food for numerous birds and herbivores, which feed on predatory animals. In a humid, warm climate, the presence of large biomass contributes to the formation of fertile soils.

Thus, components such as soil, vegetation and fauna are interconnected and depend on the amount of heat and moisture entering the territory of a given natural zone.

Didn't find what you were looking for? Use the search

On this page there is material on the following topics:

brief description of eurasia
all natural zones of Eurasia their Klamath
answers test 31 natural areas of Eurasia
what is a natural area brief definition
20 questions on the topic of natural areas of Eurasia

Introduction

Natural zonation is one of the earliest patterns in science, ideas about which deepened and improved simultaneously with the development of geography. Zoning and the presence of natural zones on the known Oecumene were found by Greek scientists of the 5th century. BC. Herodotus (485-425 BC) and Eudonyx of Cnidus (400-347 BC), distinguishing five zones: tropical, two temperate and two polar. And a little later, the Roman philosopher and geographer Posidonius (135-51 BC) further developed the doctrine of natural zones that differ from one another in climate, vegetation, hydrography, and the characteristics of the composition and occupation of the population. The latitude of the area received an exaggerated importance for him, to the point that it supposedly affects the “maturing” of precious stones.

The German naturalist A. Humboldt made a great contribution to the doctrine of natural zonality. The main feature of his works was that he considered each natural phenomenon as part of a single whole, connected with the rest of the environment by a chain of causal dependencies.

The Humboldt zones are bioclimatic in content. His views on zonation are most fully reflected in the book “Geography of Plants”, thanks to which he is deservedly considered one of the founders of the science of the same name.

The zonal principle was used already in the early period of the physical-geographical zoning of Russia, dating back to the second half of the 18th - early 19th centuries. This refers to the geographical descriptions of Russia by A.F. Bishinga, S.I. Pleshcheeva and E.F. Zyablovsky. The zones of these authors were of a complex, environmental nature, but due to limited knowledge they were extremely sketchy.

Modern ideas about geographic zoning are based on the works of V.V. Dokuchaev and F.N. Milkova.

Wide recognition of the views of V.V. Dokuchaev was greatly promoted by the works of his numerous students - N.M. Sibirtseva, K.D. Glinka, A.N. Krasnova, G.I. Tanfilyeva and others.

Further successes in the development of natural zoning are associated with the names of L.S. Berg and A.A. Grigorieva.

A.A. Grigoriev is responsible for theoretical research on the causes and factors of geographic zoning. He comes to the conclusion that in the formation of zonality, along with the value of the annual radiation balance and the amount of annual precipitation, their ratio, the degree of their proportionality, plays a huge role. He also did a lot of work to characterize the nature of the main geographical zones of land. At the center of these largely original characteristics are the physical and geographical processes that determine the landscapes of the belts and zones.

Zoning is the most important property, an expression of the orderliness of the structure of the geographical shell of the Earth. Specific manifestations of zoning are extremely diverse and are found both in physical-geographical and economic-geographical objects. Below we will talk briefly about the geographical shell of the Earth, as the main object under study, and then specifically and in detail about the law of zonation, its manifestations in nature, namely, in the wind system, the existence of climatic zones, zonality of hydrological processes, soil formation, vegetation, etc. d.

1. Geographical envelope of the Earth

.1 General characteristics of the geographical envelope

The geographic envelope is the most complex and diverse (contrasting) part of the Earth. Its specific features were formed during the long-term interaction of natural bodies under the conditions of the earth's surface.

One of the characteristic features of the shell is the wide variety of material composition, significantly exceeding the diversity of matter both in the interior of the Earth and in the upper (external) geospheres (ionosphere, exosphere, magnetosphere). In the geographic envelope, the substance is found in three states of aggregation and has a wide range of physical characteristics - density, thermal conductivity, heat capacity, viscosity, fragmentation, reflectivity, etc.

The wide variety of chemical composition and activity of the substance is striking. The material formations of the geographical shell are heterogeneous in structure. They distinguish inert, or inorganic, substance, living (the organisms themselves), bioinert substance.

Another feature of the geographic shell is the wide variety of types of energy entering it and the forms of its transformation. Among the numerous transformations of energy, a special place is occupied by the processes of its accumulation (for example, in the form of organic matter).

The uneven distribution of energy on the earth's surface, caused by the sphericity of the Earth, the complex distribution of land and ocean, glaciers, snow, topography of the earth's surface, and the variety of types of matter determine the disequilibrium of the geographical shell, which serves as the basis for the emergence of various movements: energy flows, circulation of air, water, soil solutions, migration of chemical elements, chemical reactions, etc. The movements of matter and energy connect all parts of the geographical envelope, determining its integrity.

During the development of the geographic shell as a material system, its structure became more complex, and the diversity of its material composition and energy gradients increased. At a certain stage of development of the shell, life appeared - the highest form of movement of matter. The emergence of life is a natural result of the evolution of the geographical envelope. The activity of living organisms has led to a qualitative change in the nature of the earth's surface.

A set of planetary factors is essential for the emergence and development of the geographic shell: the mass of the Earth, the distance to the Sun, the speed of rotation around the axis and in orbit, the presence of the magnetosphere, which ensured certain thermodynamic interactions - the basis of geographical processes and phenomena. The study of nearby space objects - the planets of the Solar System - showed that only on Earth did conditions develop that were favorable for the emergence of a sufficiently complex material system.

In the course of the development of the geographical shell, its role as a factor in its own development (self-development) increased. Of great independent importance are the composition and mass of the atmosphere, ocean and glaciers, the ratio and size of the areas of land, ocean, glaciers and snow, the distribution of land and sea over the earth's surface, the position and configuration of relief forms of various scales, various types of natural environment, etc.

At a fairly high level of development of the geographic shell, its differentiation and integration, complex systems emerged - natural territorial and aquatic complexes.

Let us list some of the most important parameters of the geographical shell and its large structural elements.

Earth surface area 510.2 million km 2. The ocean covers 361.1 million km 2(70.8%), land - 149.1 million km 2(29.2%). There are six large landmasses - continents, or continents: Eurasia, Africa, North America, South America, Antarctica and Australia, as well as numerous islands.

The average land height is 870 m, the average ocean depth is 3704 m. The ocean space is usually divided into four oceans: the Pacific, Atlantic, Indian and Arctic.

There is an opinion on the advisability of separating the Antarctic waters of the Pacific, Indian and Atlantic oceans into a special Southern Ocean, since this region is distinguished by a special dynamic and thermal regime.

The distribution of continents and oceans across hemispheres and latitudes is uneven, which serves as the object of special analysis.

A lot of objects are important for natural processes. The mass of the geographic envelope cannot be accurately determined due to the uncertainty of its boundaries.

.2 Horizontal structure of the geographical envelope

The differentiation of the geographic envelope in the horizontal direction is expressed in the territorial distribution of geosystems, which are represented by three levels of dimension: planetary, or global, regional and local. The most important factors determining the structure of geosystems at the global level are the sphericity of the Earth and the closedness of the space of the geographic shell. They determine the zone-zonal nature of the distribution of physical-geographical characteristics and the closedness and circularity of movements (gyres).

The distribution of land, ocean and glaciers is also an important factor that determines a certain mosaic of not only the external appearance of the earth's surface, but also the types of processes.

The dynamic factor influencing the direction of movement of matter in the geographic envelope is the Coriolis force.

The listed factors determine the general features of atmospheric and oceanic circulation, which depends on the planetary structure of the geographic envelope.

At the regional level, differences in the locations and outlines of continents and oceans, the topography of the land surface, which determine the features of the distribution of heat and moisture, types of circulation, features of the location of geographic zones and other deviations from the general picture of planetary patterns, come to the fore. In the regional plan, the position of the territory relative to the coastline, center or centerline of the mainland or water area, etc. is important.

The nature of the interaction between regional geosystems (marine or continental climate, monsoon circulation or the predominance of westerly transport, etc.) depends on these spatial factors.

The configuration of the regional geosystem, its boundaries with other geosystems, the degree of contrast between them, etc. are of significant importance.

At the local level (small parts of the region with an area from tens of square meters to tens of square kilometers), differentiation factors are various details of the relief structure (meso- and microforms - river valleys, watersheds, etc.), the composition of rocks, their physical and chemical properties , shape and exposure of slopes, type of moisture and other particular features that give the earth's surface fractional heterogeneity.

.3 Belt-zonal structures

Many physical-geographical phenomena are distributed on the earth's surface in the form of strips elongated primarily along parallels or sublatitudinally (that is, at a certain angle to them). This property of geographical phenomena is called zonality. This spatial structure is characteristic, first of all, of climatic indicators, plant groups, and soil types; it manifests itself in hydrological and geochemical phenomena as a derivative of the former. The zonality of physical-geographical phenomena is based on the well-known pattern of solar radiation entering the earth's surface, the arrival of which decreases from the equator to the poles according to the cosine law. If it were not for the peculiarities of the atmosphere and the underlying surface, then the arrival of solar radiation - the energetic basis of all processes in the shell - would be precisely determined by this law. However, the earth's atmosphere has varying transparency depending on cloudiness, as well as dust content, the amount of water vapor and other components and impurities. The distribution of atmospheric transparency has, among others, a zonal component, which is easy to see in a satellite image of the Earth: on it, stripes of clouds form belts (especially along the equator and in temperate and polar latitudes). Thus, the correct natural decrease in the arrival of solar radiation from the equator to the poles is superimposed on a more motley picture of atmospheric transparency, which acts as a differentiating factor of solar radiation.

Air temperature depends on solar radiation. However, the nature of its distribution is influenced by another differentiating factor - the thermal properties of the earth's surface (heat capacity, thermal conductivity), which causes an even greater mosaic of temperature distribution (compared to solar radiation). The distribution of heat, and therefore surface temperatures, is influenced by ocean and air currents that form heat transfer systems.

Atmospheric precipitation is distributed even more complexly across the globe. They have two clearly defined components: zonal and sectoral, associated with the position on the western or eastern part of the continent, on land or at sea. The patterns of spatial distribution of the listed climatic factors are presented on maps of the Physiographic Atlas of the World.

The combined effect of heat and moisture is the main factor that determines most physical and geographical phenomena. Since the distribution of moisture and, especially, heat remains latitudinal, all climate-derived phenomena are oriented accordingly. A conjugate spatial system is created that has a latitudinal structure. It is called geographical zonality. The belt structure of natural phenomena on the earth's surface was first quite clearly noted by A. Humboldt, although about thermal belts, i.e. based on geographical zonation, was known back in Ancient Greece. At the end of the last century V.V. Dokuchaev formulated the world law of zoning. In the first half of our century, scientists began to talk about geographical zones - elongated territories with the same type of many physical and geographical phenomena and their interactions.

2. Law of zoning

.1 Concept of zoning

In addition to territorial differentiation in general, the most characteristic structural feature of the geographical envelope of the Earth is a special form of this differentiation - zonality, i.e. a natural change in all geographical components and geographical landscapes along latitude (from the equator to the poles). The main reasons for zonation are the shape of the Earth and the position of the Earth relative to the Sun, and the prerequisite is the incidence of solar rays on the Earth's surface at an angle that gradually decreases on both sides of the equator. Without this cosmic prerequisite, there would be no zonality. But it is also obvious that if the Earth were not a ball, but a plane, oriented in any way to the flow of solar rays, the rays would fall on it everywhere equally and, therefore, would heat the plane equally at all its points. There are features on Earth that outwardly resemble latitudinal geographic zoning, for example, the successive change from south to north of the belts of terminal moraines, piled up by the retreating ice sheet. They sometimes talk about the zonality of the relief of Poland, because here, from north to south, stripes of coastal plains, terminal moraine ridges, Middle Poland lowlands, hills on a folded-block foundation, ancient (Hercynian) mountains (Sudetes) and young (Tertiary) folded mountains replace each other. (Carpathians). They even talk about the zonality of the Earth's megarelief. However, only what is directly or indirectly caused by a change in the angle of incidence of the sun's rays on the earth's surface can refer to truly zonal phenomena. What is similar to them, but arises for other reasons, must be called differently.

G.D. Richter, following A.A. Grigoriev, proposes to distinguish between the concepts of zonality and zonality, while dividing the belts into radiation and thermal ones. The radiation belt is determined by the amount of incoming solar radiation, which naturally decreases from low to high latitudes.

This influx is influenced by the shape of the Earth, but is not affected by the nature of the Earth's surface, which is why the boundaries of the radiation belts coincide with the parallels. The formation of thermal belts is no longer controlled only by solar radiation. Here, the properties of the atmosphere (absorption, reflection, dissipation of radiant energy), the albedo of the earth's surface, and the transfer of heat by sea and air currents are important, as a result of which the boundaries of thermal zones cannot be combined with parallels. As for geographical zones, their essential features are determined by the relationship between heat and moisture. This ratio depends, of course, on the amount of radiation, but also on factors only partially related to latitude (the amount of advective heat, the amount of moisture in the form of precipitation and runoff). That is why the zones do not form continuous stripes, and their extension along parallels is more a special case than a general law.

If we summarize the above considerations, they can be reduced to the thesis: zonality acquires its specific content in the special conditions of the geographical envelope of the Earth.

To understand the very principle of zonality, it is quite indifferent whether we call the belt a zone or the zone a belt; these shades have more taxonomic than genetic significance, since the amount of solar radiation equally forms the foundation for the existence of both belts and zones.

.2 Periodic law of geographical zoning

V. Dokuchaev's discovery of geographical zones as integral natural complexes was one of the largest events in the history of geographical science. After this, for almost half a century, geographers were engaged in concretizing and, as it were, “materially filling” this law: the boundaries of the zones were clarified, their detailed characteristics were made, the accumulation of factual material made it possible to identify subzones within the zones, the heterogeneity of zones along the strike was established (identification of provinces), and the reasons were investigated pinching out zones and deviating their direction from the theoretical, a grouping of zones was developed within larger taxonomic divisions - belts, etc.

A fundamentally new step in the problem of zoning was made by A.A. Grigoriev and M.I. Budyko, who provided a physical and quantitative basis for the phenomena of zonation and formulated the periodic law of geographic zonation, which underlies the structure of the Earth’s landscape envelope.

The law is based on taking into account three closely interrelated factors. One of them is the annual radiation balance (R) of the earth's surface, i.e. the difference between the amount of heat absorbed by that surface and the amount of heat given off by it. The second is the annual amount of precipitation (r). The third, called the radiation dryness index (K), represents the ratio of the first two:

K = ,

where L is the latent heat of evaporation.

Dimension: R in kcal/cm 2 per year, r - in g/cm 2, L - in kcal/g per year, - in kcal/cm2 .

It turned out that the same value of K is repeated in zones belonging to different geographical zones. In this case, the K value determines the type of landscape zone, and the R value determines the specific character and appearance of the zone (Table I). For example, K>3 in all cases indicates the type of desert landscapes, but depending on the value of R, i.e. depending on the amount of heat, the appearance of the desert changes: at R = 0-50 kcal/cm 2per year is a temperate desert, at R = 50-75 it is a subtropical desert and at R>75 it is a tropical desert.

If K is close to unity, this means that there is a proportionality between heat and moisture: as much precipitation falls as can evaporate. This index ensures the uninterrupted processes of evaporation and transpiration, as well as soil aeration, for biological components. A deviation of K in both directions from unity creates disproportions: with a lack of moisture (K>1), the uninterrupted flow of evaporation and transpiration processes is disrupted, with an excess of moisture (K<1) - процессов аэрации; и то и другое сказывается на биокомпонентах отрицательно.

The significance of the works of M.I. Budyko and A.A. Grigoriev’s message is twofold: 1) a characteristic feature of zoning is emphasized - its periodicity, which can be comparable to the importance of the discovery of D.I. Mendeleev's periodic law of chemical elements; 2) indicative quantitative indicators have been established for drawing the boundaries of landscape zones.

.3 Landscape areas

Modern ideas about the connections and interactions of individual components of the Earth’s landscape envelope make it possible to construct a theoretical model of landscape zones on land using the example of the so-called homogeneous ideal continent (Fig. 1). Its dimensions correspond to half the land area of the globe, its configuration corresponds to its location along latitudes, and its surface is a low plain; in place of mountain systems, zone types are extrapolated.

From the diagram of a hypothetical continent, two main conclusions must be drawn: 1) most geographical zones do not have a west-east strike and, as a rule, do not encircle the globe and 2) each zone has its own sets of zones.

The explanation for this is that land and sea on Earth are distributed unevenly, the shores of the continents are washed in some cases by cold, in others by warm sea currents, and the land topography is very diverse. The distribution of zones also depends on atmospheric circulation, i.e. on the direction of advection of heat and moisture. If meridional transfer dominates (i.e. it coincides with a latitudinal change in the amount of radiative heat), the zonality will often be latitudinal; in the case of western or eastern (i.e. zonal) transfer, latitudinal zonality is rather an exception, the zones acquire different extents and outlines (bands, spots, etc.) and are not very extended. At the same time, the essential features of natural zones develop under the influence of humidification and advection of heat (or cold) during the warm season.

The analysis of the actual picture of geographic zoning should be preceded by the division of the earth's surface into geographical zones. Now the belts are usually distinguished: polar, subpolar, temperate, tropical, subtropical, subequatorial and equatorial. In other words, a geographic zone is understood as a latitudinal division of a geographic envelope determined by climate. However, the main point of identifying geographic zones is to outline only the most general features of the distribution of the primary zoning factor, i.e. heat, so that against this general background one can outline the first largest details (also of a fairly general nature) - landscape zones. This requirement is fully satisfied by dividing each hemisphere into cold, temperate and hot zones. The boundaries of these zones are drawn according to isotherms, which in specific quantities reflect the influence on the heat distribution of all factors - insolation, advection, degree of continentality, height of the Sun above the horizon, duration of illumination, etc. According to V.B. Sochava, only three zones should be considered the main links of planetary zonation: northern extratropical, tropical and southern extratropical.

Recently, in the geographical literature there has been a tendency to increase not only the number of geographical zones, but also the number of landscape zones. V.V. Dokuchaev in 1900 spoke about seven zones (boreal, northern forest, forest-steppe, chernozem, dry steppes, aerial, lateritic), L.S. Berg (1938) - about 12, P.S. Makeev (1956) already describes about three dozen zones. The Physiographic Atlas of the World identifies 59 zonal (i.e., falling into zones and subzones) types of land landscapes.

A landscape (geographical, natural) zone is a large part of a geographical zone, characterized by the dominance of any one zonal type of landscape.

The names of landscape zones are most often given on a geobotanical basis, since vegetation cover is an extremely sensitive indicator of various natural conditions. It is necessary, however, to keep two points in mind. First: the landscape zone is not identical to the geobotanical, soil, geochemical or any other zone objectively identified by a separate component of the Earth’s landscape shell. In the tundra landscape zone there is not only a type of tundra vegetation, but also forests along the river valleys. In the landscape zone of steppes, soil scientists place both a zone of chernozems and a zone of chestnut soils, etc. Second: the appearance of any landscape zone is created not only by the totality of modern natural conditions, but also by the history of their formation. In particular, the systematic composition of flora and fauna does not in itself provide an idea of zonation. The zonal features of vegetation and fauna are determined by the adaptation of their representatives (and even more so by their communities, biocenoses) to the ecological situation and, as a consequence, the development in the process of evolution of a complex of life forms that corresponds to the geographical content of the landscape zone.

At the first stages of studying zonality, it was taken for granted that the zonality of the southern hemisphere was just a mirror image of the zonality of the northern hemisphere, somewhat impaired by the smaller size of continental spaces. As will be seen from what follows, such assumptions were not justified and must be abandoned.

Extensive literature is devoted to the experience of dividing the globe into landscape zones and describing the zones. The division schemes, despite some differences, in all cases convincingly prove the reality of landscape zones.

3. Manifestation of zoning

.1 Forms of manifestation

Due to the zonal distribution of solar radiant energy on Earth, the following are zonal: air, water and soil temperatures, evaporation and cloudiness, precipitation, baric relief and wind systems, properties of air masses, climates, the nature of the hydrographic network and hydrological processes, features of geochemical processes, weathering and soil formations, types of vegetation and life forms of plants and animals, sculptural forms of relief, to a certain extent types of sedimentary rocks, and finally, geographical landscapes, united in this regard into a system of landscape zones.

The zoning of thermal conditions was already known to geographers of ancient times; In some of them one can also find elements of ideas about the natural zones of the Earth. A. Humboldt established the zonation and altitudinal zonation of vegetation. But the honor and merit of the true scientific discovery of geographical zoning belongs to V.V. Dokuchaev. It led to huge shifts in the content of geography and its theoretical basis. V.V. Dokuchaev called zonality a world law. However, it would be a mistake to take this literally, since the scientist, of course, had in mind the universality of the manifestation of zonality only on the surface of the globe.

As you move away from the earth's surface (up or down), the zonality gradually fades. For example, in the abyssal region of the oceans, a constant and rather low temperature prevails everywhere (from -0.5 to +4°), sunlight does not penetrate here, there are no plant organisms, the water masses practically remain almost completely at rest, i.e. There are no reasons that could cause the emergence and change of zones on the ocean floor. Some hint of zoning could be seen in the distribution of marine sediments: coral deposits are confined to tropical latitudes, diatomaceous oozes to polar latitudes. But this is only a passive reflection on the seabed of those zonal processes that are characteristic of the ocean surface, where the habitats of coral colonies and diatoms are actually located according to the laws of zonation. The remains of diatom shells and the products of destruction of coral structures are simply “designed” to the bottom of the sea, regardless of the conditions that exist there.

Zoning is also blurred in high layers of the atmosphere. The source of energy in the lower atmosphere is the earth's surface illuminated by the Sun. Consequently, solar radiation plays an indirect role here, and processes in the lower atmosphere are regulated by the flow of heat from the earth's surface. As for the upper atmosphere, the most significant phenomena for it are a consequence of the direct influence of the Sun. The reason for the decrease in temperature with height in the troposphere (on average 6° per kilometer) is the distance from the main energy source for the troposphere (Earth). The temperature of the high layers does not depend on the earth's surface and is determined by the balance of radiant energy of the air particles themselves. Apparently, the line of influence lies at an altitude of about 20 km, because higher (up to 90-100 km) there is a dynamic system independent of the tropospheric one.

Zonal differences in the earth's crust are quickly disappearing. Seasonal and daily temperature fluctuations cover a rock layer no more than 15-30 m thick; at this depth a constant temperature is established, the same all year round and equal to the average annual air temperature of the given area. Below the permanent layer, the temperature increases with depth. And its distribution, both in the vertical and horizontal directions, is no longer associated with solar radiation, but with the energy sources of the earth’s interior, which, as is known, supports azonal processes.

In all cases, zoning fades as it approaches the boundaries of the landscape envelope, and this can serve as an auxiliary diagnostic feature for establishing these boundaries.

The position of the Earth in the solar system and, partly, the size of the Earth are of considerable importance in the phenomena of zonation. On Pluto, the outermost member of the solar system, which receives 1600 times less heat from the Sun than the Earth, there are no zones: its surface is a continuous icy desert. The moon, due to its small size, was unable to maintain an atmosphere around itself. That is why there is no water or organisms on our satellite, and there are no visible traces of zonation. There is rudimentary visible zoning on Mars: two polar caps and the space between them. Here, the reason for the embryonic nature of the zones is not only the distance from the Sun (it is one and a half times greater than the Earth's), but also the small mass of the planet (0.11 Earth's), as a result of which the gravity force is less (0.38 Earth's) and the atmosphere is extremely rarefied: at 0° and pressure 1 kg/cm 2it would be “compressed” into a layer only 7 m thick, and the roof of any of our city houses would be outside the air shell of Mars under these conditions.

The law of zoning has met and continues to meet with objections from some authors. In the 1930s, some Soviet geographers, mainly soil scientists, took up the task of “revising” Dokuchaev’s law of zonation, and the doctrine of climatic zones was even declared scholastic. The real existence of zones was denied by this consideration: the earth's surface in its appearance and structure is so complex and mosaic that it is possible to identify zonal features on it only through great generalization. In other words, there are no specific zones in nature; they are the fruit of an abstract logical construction. The helplessness of such argumentation is striking because: 1) any general law (of nature, society, thinking) is established by the method of generalization, abstraction from particulars, and it is with the help of abstraction that science moves from knowledge of a phenomenon to knowledge of its essence; 2) no generalization is able to reveal what actually does not exist.

However, the “campaign” against the zonal concept also brought positive results: it served as a serious impetus for a more detailed one than V.V. Dokuchaev, development of the problem of internal heterogeneity of natural zones, to the formation of the concept of their provinces (facies). Let us note in passing that many opponents of zoning soon returned to the camp of its supporters.

Other scientists, without denying zonality in general, deny only the existence of landscape zones, believing that zonality is only a bioclimatic phenomenon, because it does not affect the lithogenic basis of the landscape created by azonal forces.

The fallacy of the reasoning stems from an incorrect understanding of the lithogenic basis of the landscape. If we attribute to it the entire geological structure underlying the landscape, then, of course, there is no zonation of landscapes taken in the totality of their components, and it will take millions of years to change the entire landscape. It is useful, however, to remember that landscapes on land arise in areas of contact between the lithosphere and the atmosphere, hydrosphere and biosphere. Therefore, the lithosphere must be included in the landscape to the depth to which its interaction with exogenous factors extends. This lithogenic base is inextricably linked and changes in conjunction with all other components of the landscape. It cannot be separated from the bioclimatic components, and, therefore, it becomes as zonal as these latter. By the way, living matter included in the bioclimatic complex is azonal in nature. It acquired zonal features during adaptation to specific environmental conditions.

3.2 Heat distribution on Earth

There are two main mechanisms in the heating of the Earth by the Sun: 1) solar energy is transmitted through space in the form of radiant energy; 2) radiant energy absorbed by the Earth is converted into heat.

The amount of solar radiation received by the Earth depends on:

on the distance between the Earth and the Sun. The Earth is closest to the Sun in early January, farthest in early July; the difference between these two distances is 5 million km, as a result of which the Earth in the first case receives 3.4% more, and in the second 3.5% less radiation than with the average distance from the Earth to the Sun (in early April and at the beginning of October);
on the angle of incidence of the sun's rays on the earth's surface, which in turn depends on the geographic latitude, the height of the Sun above the horizon (changing throughout the day and with the seasons), and the nature of the topography of the earth's surface;
from the transformation of radiant energy in the atmosphere (scattering, absorption, reflection back into space) and on the surface of the Earth. The average albedo of the Earth is 43%.

The picture of the annual heat balance by latitudinal zones (in calories per 1 square cm per 1 minute) is presented in Table II.

The absorbed radiation decreases towards the poles, but long-wave radiation remains virtually unchanged. The temperature contrasts that arise between low and high latitudes are softened by the transfer of heat by sea and mainly air currents from low to high latitudes; the amount of heat transferred is indicated in the last column of the table.

For general geographic conclusions, rhythmic fluctuations in radiation due to changing seasons are also important, since the rhythm of the thermal regime in a particular area depends on this.

Based on the characteristics of the Earth's irradiation at different latitudes, it is possible to outline the “rough” contours of thermal belts.

In the zone between the tropics, the rays of the Sun at noon always fall at a large angle. The sun is at its zenith twice a year, the difference in the length of day and night is small, and the heat influx throughout the year is large and relatively uniform. This is a hot zone.

Between the poles and polar circles, day and night can separately last more than a day. On long nights (in winter) there is strong cooling, since there is no heat influx at all, but on long days (in summer) the heating is insignificant due to the low position of the Sun above the horizon, reflection of radiation by snow and ice, and waste of heat on melting snow and ice. This is a cold belt.

Temperate zones are located between the tropics and the polar circles. Since the Sun is high in summer and low in winter, temperature fluctuations throughout the year are quite large.

However, in addition to geographic latitude (and therefore solar radiation), the distribution of heat on Earth is also influenced by the nature of the distribution of land and sea, relief, altitude above sea level, sea and air currents. If we take these factors into account, then the boundaries of thermal zones cannot be combined with parallels. That is why isotherms are taken as boundaries: annual ones - to highlight the zone in which the annual air temperature amplitudes are small, and isotherms of the warmest month - to highlight those zones where temperature fluctuations in the year are sharper. Based on this principle, the following thermal zones are distinguished on Earth:

) warm or hot, limited in each hemisphere by the annual isotherm +20°, passing near the 30th north and 30th south parallels;

3) two temperate zones, which in each hemisphere lie between the annual isotherm +20° and the isotherm +10° of the warmest month (July or January, respectively); in Death Valley (California) the highest July Temperature on the globe was recorded at + 56.7°;

5) two cold belts, in which the average temperature of the warmest month in a given hemisphere is less than +10°; sometimes two areas of perpetual frost are distinguished from cold belts with the average temperature of the warmest month below 0°. In the northern hemisphere, this is the interior of Greenland and possibly the area near the pole; in the southern hemisphere - everything that lies south of the 60th parallel. Antarctica is especially cold; here in August 1960, at Vostok station, the lowest air temperature on Earth was recorded -88.3°.

The connection between the distribution of temperature on Earth and the distribution of incoming solar radiation is quite clear. However, a direct relationship between the decrease in average values of incoming radiation and the decrease in temperature with increasing latitude exists only in winter. In the summer, for several months in the area of the North Pole, due to the longer day length here, the amount of radiation is noticeably higher than at the equator (Fig. 2). If the summer temperature distribution corresponded to the radiation distribution, then the summer air temperature in the Arctic would be close to tropical. This is not the case only because there is ice cover in the polar regions (snow albedo in high latitudes reaches 70-90% and a lot of heat is spent on melting snow and ice). In its absence in the Central Arctic, summer temperatures would be 10-20°, winter 5-10°, i.e. A completely different climate would have formed, in which the Arctic islands and coasts could have been covered with rich vegetation, if this had not been prevented by the many-day and even many-month-long polar nights (the impossibility of photosynthesis). The same would happen in Antarctica, only with shades of “continentality”: summers would be warmer than in the Arctic (closer to tropical conditions), winters would be colder. Therefore, the ice cover of the Arctic and Antarctic is more a cause than a consequence of low temperatures at high latitudes.

These data and considerations, without violating the actual, observed regularity of the zonal distribution of heat on Earth, pose the problem of the genesis of thermal belts in a new and somewhat unexpected context. It turns out, for example, that glaciation and climate are not a consequence and a cause, but two different consequences of one common cause: some change in natural conditions causes glaciation, and under the influence of the latter, decisive climate changes occur. And yet, at least local climate change must precede glaciation, because the existence of ice requires very specific conditions of temperature and humidity. A local mass of ice can affect the local climate, allowing it to grow, then change the climate of a larger area, giving it an incentive to grow further, and so on. When such a spreading “ice lichen” (Gernet’s term) covers a huge space, it will lead to a radical change in the climate in this space.

.3 Baric relief and wind system

zonation geographic pressure

In the Earth's pressure field, the zonal distribution of atmospheric pressure is quite clearly revealed, symmetrical in both hemispheres.

Maximum pressure values are confined to the 30-35th parallels and polar regions. Subtropical high pressure zones are expressed throughout the year. However, in the summer, due to the heating of the air over the continents, they break apart, and then separate anticyclones separate over the oceans: in the northern hemisphere - the North Atlantic and North Pacific, in the southern - the South Atlantic, South Indian, South Pacific and New Zealand (northwest of New Zealand ).

The minimum atmospheric pressure is at 60-65 parallels of both hemispheres and in the equatorial zone. The equatorial pressure depression is stable during all months, with its axial part located on average at about 4° N. w.

In the middle latitudes of the northern hemisphere, the pressure field is varied and variable, since here vast continents alternate with oceans. In the southern hemisphere, with its more homogeneous water surface, the pressure field changes slightly. From 35° south w. towards Antarctica the pressure drops rapidly and a band of low pressure surrounds Antarctica.

In accordance with the pressure relief, the following wind zones exist:

) equatorial zone of calms. Winds are relatively rare (since ascending movements of highly heated air dominate), and when they do occur, they are variable and squally;

3) trade wind zones of the northern and southern hemispheres;

5) quiet areasin anticyclones of the subtropical high pressure zone; the reason is the dominance of downward air movements;

7) in the middle latitudes of both hemispheres - zones of predominance of westerly winds;

9) in circumpolar spaces, winds blow from the poles towards the pressure depressions of mid-latitudes, i.e. common here winds with easterly component.

The actual circulation of the atmosphere is more complex than reflected in the climatological scheme outlined above. In addition to the zonal type of circulation (transfer of air along parallels), there is also a meridional type - transfer of air masses from high latitudes to low latitudes and back. In a number of areas of the globe, under the influence of temperature contrasts between land and sea and between the northern and southern hemispheres, monsoons arise - stable air currents of a seasonal nature, changing direction from winter to summer to the opposite or close to the opposite. On the so-called fronts (transition zones between different air masses) cyclones and anticyclones form and move. In the middle latitudes of both hemispheres, cyclones originate mainly in the zone between the 40th and 60th parallels and rush to the east. The tropical cyclone region lies between 10 and 20° north and south latitudes over the warmest parts of the oceans; these cyclones move in a westerly direction. Those anticyclones that follow cyclones are more mobile than the more or less stationary anticyclones of the subtropical high pressure belt or winter pressure maxima over the continents.

Air circulation in the upper troposphere, tropopause and stratosphere is different than in the lower troposphere. There, jet streams play a big role - narrow zones of strong winds (on the jet axis 35-40, sometimes up to 60-80 and even up to 200 m/sec) with a thickness of 2-4 km, and a length of tens of thousands of kilometers (sometimes they encircle the entire globe), generally running from west to east at an altitude of 9-12 km (in the stratosphere - 20-25 km). The known jet currents are mid-latitudes, subtropical (between 25 and 30° N at an altitude of 12-12.5 km), western stratospheric on the Arctic Circle (only in winter), eastern stratospheric on average along 20° N. w. (only in summer). Modern aviation is forced to take into account jet currents, which either noticeably slow down the speed of the aircraft (counter) or increase it (passing).

.4 Climate zones of the Earth

Climate is the result of the interaction of many natural factors, the main of which are the arrival and consumption of radiant energy from the Sun, atmospheric circulation, which redistributes heat and moisture, and moisture circulation, which is practically inseparable from atmospheric circulation. Atmospheric circulation and moisture circulation generated by the distribution of heat on Earth, in turn, affect the thermal conditions of the globe, and consequently, everything that is directly or indirectly controlled by them. Cause and effect are intertwined here so closely that all three factors should be considered as a complex unity.

Each of these factors depends on the geographic location of the area (latitude, altitude above sea level) and the nature of the earth's surface. Latitude determines the amount of solar radiation influx. With altitude, the temperature and pressure of the air, its moisture content, and the conditions of wind movement change. Features of the earth's surface (ocean, land, warm and cold sea currents, vegetation, soil, snow and ice cover, etc.) greatly affect the radiation balance and, therefore, atmospheric circulation and moisture circulation. In particular, under the powerful transformative influence of the underlying surface on air masses, two main types of climate are formed: marine and continental.

Since all factors of climate formation, except topography and the location of land and sea, tend to be zonal, it is quite natural that climates are zonal.

B.P. Alisov divides the globe into the following climatic zones (Fig. 4):

. Equatorial zone.Light winds prevail. The differences in temperature and humidity between seasons are very small and less than daily. Average monthly temperatures range from 25 to 28°. Precipitation - 1000-3000 mm. Hot, humid weather with frequent showers and thunderstorms prevails.

Subequatorial zones.Seasonal changes in air masses are characteristic: in summer the monsoon blows from the equator, in winter - from the tropics. Winter is only slightly cooler than summer. When the summer monsoon dominates, the weather is approximately the same as in the equatorial zone. Inside the continents, precipitation rarely exceeds 1000-1500 mm, but on the monsoon-facing mountain slopes the amount of precipitation reaches 6000-10,000 mm per year. Almost all of them fall in the summer. Winter is dry, the daily temperature range increases compared to the equatorial zone, and the weather is cloudless.
Tropical zones of both hemispheres.Predominance of trade winds. The weather is mostly clear. Winter is warm, but noticeably colder than summer. In tropical zones one can distinguish three types of climate: a) areas of stable trade winds with cool, almost rainless weather, high air humidity, with fogs and strong breezes developed on the coasts (the western coast of South America between 5 and 20° N, the Sahara coast, the Namib Desert); b) trade wind areas with passing rains (Central America, West Indies, Madagascar, etc.); c) hot arid regions (Sahara, Kalahari, most of Australia, northern Argentina, southern half of the Arabian Peninsula).
Subtropical zones.Distinct seasonal variations in temperature, precipitation and winds. It is possible, but very rare, for snow to fall. With the exception of monsoon regions, anticyclonic weather prevails in summer and cyclonic activity in winter. Climate types: a) Mediterranean with clear and quiet summers and rainy winters (Mediterranean, central Chile, Cape Land, southwest Australia, California); b) monsoon regions with hot, rainy summers and relatively cold and dry winters (Florida, Uruguay, northern China); c) dry areas with hot summers (the southern coast of Australia, Turkmenistan, Iran, Taklimakan, Mexico, the dry west of the USA); d) areas that are evenly moist throughout the year (southeast Australia, Tasmania, New Zealand, the middle part of Argentina).
Temperate climate zones.There is cyclonic activity over the oceans in all seasons. Frequent precipitation. Predominance of westerly winds. Strong temperature differences between winter and summer and between land and sea. In winter it snows. Main types of climates: a) winter with unstable weather and strong winds, summer weather is calmer (Great Britain, Norwegian coast, Aleutian Islands, Gulf of Alaska coast); b) different continental climate options (inland USA, south and southeast of European Russia, Siberia, Kazakhstan, Mongolia); c) transitional from continental to oceanic (Patagonia, most of Europe and the European part of Russia, Iceland); d) monsoon regions (Far East, Okhotsk coast, Sakhalin, northern Japan); e) areas with humid, cool summers and cold, snowy winters (Labrador, Kamchatka).
Subpolar zones.Large temperature differences between winter and summer. Permafrost.
Polar zones.Large annual and small daily temperature fluctuations. There is little precipitation. Summer is cold and foggy. Climate types: a) with relatively warm winters (coasts of the Beaufort Sea, Baffin Island, Severnaya Zemlya, Novaya Zemlya, Spitsbergen, Taimyr, Yamal, Antarctic Peninsula); b) with cold winters (Canadian archipelago, New Siberian Islands, coasts of the East Siberian and Laptev seas); c) with very cold winters and summer temperatures below 0° (Greenland, Antarctica).

.5 Zoning of hydrological processes

The forms of hydrological zoning are varied. The zoning of the thermal regime of waters in connection with the general features of temperature distribution on Earth is obvious. The mineralization of groundwater and the depth of its occurrence have zonal features - from ultra-fresh and close to the surface in the tundra and equatorial forests to brackish and saline waters of deep occurrence in deserts and semi-deserts.

The runoff coefficient is zoned: in Russia in the tundra it is 0.75, in the taiga - 0.65, in the mixed forest zone - 0.30, in the forest-steppe - 0.17, in the steppe and semi-deserts - from 0.06 to 0.04 .

The relationships between different types of runoff are zonal: in the glacial belt (above the snow line) runoff takes the form of the movement of glaciers and avalanches; in the tundra, soil runoff predominates (with temporary aquifers within the soil) and swamp-type surface runoff (when the groundwater level is above the surface); In the forest zone, groundwater runoff dominates, in steppes and semi-deserts - surface (slope) runoff, and in deserts there is almost no runoff. The channel flow also bears the imprint of zonality, which is reflected in the water regime of rivers, depending on the conditions of their feeding. M.I. Lvovich notes the following features.

In the equatorial belt, river flow is abundant all year round (Amazon, Congo, rivers of the Malay Archipelago).

Summer runoff due to the predominance of summer precipitation is typical for the tropical zone, and in the subtropics - for the eastern edges of the continents (Ganges, Mekong, Yangtze, Zambezi, Parana).

In the temperate zone and on the western edges of the continents in the subtropical zone, four types of river regime are distinguished: in the Mediterranean zone - the predominance of winter flow, since the maximum precipitation here is in winter; the predominance of winter runoff with a uniform distribution of precipitation throughout the year, but with strong evaporation in summer (British Isles, France, Belgium, the Netherlands, Denmark); predominance of spring rain runoff (eastern part of Western and Southern Europe, most of the USA, etc.); predominance of spring snow runoff (Eastern Europe, Western and Central Siberia, northern USA, southern Canada, southern Patagonia).

In the boreal-subarctic zone, there is snow feeding in summer, and in winter there is drying up of runoff in permafrost areas (the northern outskirts of Eurasia and North America).

In high-latitude zones, water is in the solid phase almost the entire year (Arctic, Antarctic).

3.6 Zoning of soil formation

The type of soil formation is determined mainly by climate and the nature of vegetation. In accordance with the zonality of these main factors, soils on Earth are also located zonally.

For the region of polar soil formation, which occurs with very little participation of microorganisms, zones of arctic and tundra soils are typical. The former are formed in a relatively dry climate, are thin, the soil cover is not continuous, and saline phenomena are observed. Tundra soils are wetter, peaty and superficially gleyish.

In the area of boreal soil formation, soils of subpolar forests and meadows, permafrost-taiga and podzolic soils are distinguished. The annual death of grasses introduces a lot of organic matter into the soils of subpolar forests and meadows, which contributes to the accumulation of humus and the development of the illuvial-humus process; types of soddy-coarse-humus and soddy-peaty soils arise.

The area of permafrost-taiga soils coincides with the area of permafrost and is confined to the larch light-coniferous taiga. Cryogenic phenomena impart complexity (mosaicity) to the soil cover here; podzol formation is absent or weakly expressed.

The zone of podzolic soils is characterized by gley-podzolic, podzolic, podzolic and sod-podzolic soils. More atmospheric precipitation falls than evaporates, so the soil is vigorously washed, easily soluble substances are carried out from the upper horizons and accumulate in the lower ones; the division of the soil into horizons is clear. The zone of podzolic soils corresponds mainly to the zone of coniferous forests. Soddy-podzolic soils develop in mixed forests with grass cover. They are richer in humus, since there is more calcium in forest herbs and leaves than in the litter of coniferous trees; calcium promotes the accumulation of humus, because it protects it from destruction and leaching.

The zonal types of soils in the subboreal region are very diverse. soil formation. In areas of humid climate, brown and gray forest soils and chernozem-like soils of prairies were formed, in steppe areas - chernozems and chestnut soils. There is little precipitation, evaporation is high, the soil is poorly washed, so the soil profile is not sufficiently differentiated and genetic horizons gradually transform into each other. The richness of parent rocks and plant litter in salts leads to the fact that soil solutions are enriched with electrolytes, the absorbing complex is saturated with calcium and its colloids are in a coagulated state. Every year, dying herbaceous vegetation supplies the soil with a huge amount of plant residues. However, their mineralization is difficult, since the activity of bacteria is constrained by low temperatures in winter and by lack of moisture in summer. Hence the accumulation of incomplete decomposition products and the enrichment of the soil with humus.

In semi-deserts and deserts, light chestnut, brown semi-desert and gray-brown desert soils are common. They are often combined with takyr spots and sand massifs. Their profile is short, there is little humus, and the salt content is significant. Saline soils are very common - solods, solonetzes and even solonchaks. The abundance of salts is associated with the dryness of the climate, the poverty of humus is associated with the poverty of the vegetation cover. In the humid climate of the region of subtropical soil formation, for example, in humid subtropical forests, yellow-brown and red-yellow soils (zheltozems and krasnozems) are common. In the semi-arid conditions of the same region there are brown soils of xerophytic forests and shrubs, and in an arid climate there are gray-brown soils and gray soils of ephemeral meadow-steppes and reddish soils of subtropical deserts.

The parent rock in areas of tropical soil formation is usually laterites. In humid climate areas, despite the fact that a lot of organic waste enters the soil, organic residues, due to the abundance of heat and moisture all year round, decompose completely and do not accumulate in the soil. In this environment, red-yellow lateritic soils are formed, often podzolized under forests (they are sometimes called tropical podzols); but on basic (in the chemical sense) rocks (basalts, etc.) very fertile dark-colored lateritic soils are formed.

In warm countries, where dry and wet seasons alternate throughout the year, the soils are red lateritic and brown-red lateritized.

In dry savannas the soils are red-brown. The soil cover of tropical deserts has been little studied. Here sandy and rocky spaces alternate with salt marshes and outcrops of ancient lateritic weathering crust. Compiled by V.A. Kovdoy, B.G. Rozanov and E.M. Samoilova's map of soil-geochemical formations, identified not by the location of soils in certain bioclimatic zones, but by the commonality of the most important soil properties, confirms the zonal location of these formations on all continents.

.7 Zoning of vegetation types

For millions of years, living organic matter and the geographical envelope of the Earth have been inseparable. This or that manifestation of life constitutes the most remarkable feature of any geographical landscape, depending on the history of the landscape and the ecological relationships that have developed in it. An indicator of the closest connection between organisms and their habitat is adaptation, which, covering all the properties of living beings, helps them make the best possible use of the geographical environment and ensure not only life, but also reproduction.

Animals that can move actively and far have an important advantage over stationary plants and stationary and sedentary animals: to a certain extent, they choose their habitat conditions, leaving unfavorable ones for more suitable ones. However, this does not eliminate their dependence on the environment, but only expands the scope of adaptation to it.

The environment for plants, as for other organisms, is the entire set of components of the geographical envelope of the Earth.

On the plains of the cold countries of the northern hemisphere lie arctic deserts and tundras - treeless spaces dominated by mosses, lichens and dwarf shrubs and subshrubs, both shedding their leaves for the winter and evergreens. From the south, the tundra is framed everywhere by forest-tundra.

In temperate countries, a significant area is under coniferous forests (taiga), forming an entire zone in Eurasia and North America. South of the taiga is a zone of mixed and deciduous forests, best expressed in Western Europe and the eastern third of the United States. These forests naturally give way to forest-steppe and steppes - zones with a predominance of herbaceous communities of a more or less xerophytic appearance and with a more or less closed herbage, replete with turf grasses and dry-loving species of forbs (remember that forbs include all herbaceous plants, except for cereals, legumes and sedges). There are steppes in Mongolia, in the south of Siberia and the European part of the USSR, in the USA (prairies). In the southern hemisphere they occupy smaller spaces. The type of desert vegetation is also widespread in the temperate zone, in which the area of bare soil is much larger than under vegetation, and in which xerophilic subshrubs dominate among the plants. Vegetation, transitional between steppe and desert, is characteristic of semi-deserts.

In warm countries there are plant communities similar to some phytocenoses of temperate countries: coniferous, mixed and deciduous forests, deserts. But these phytocenoses are composed of different plant species and have some of their own ecological characteristics. The desert zone (Africa, Asia, Australia) emerges especially clearly here.

At the same time, in warm countries, plant communities that are unique to them are common: evergreen hard-leaved forests, savannas, dry woodlands, and tropical rainforests.

Evergreen hard-leaved forests are a kind of emblem of countries with a Mediterranean climate. These forests consist of eucalyptus trees (Australia), various types of oak, noble laurel and other species. When there is a lack of moisture, instead of forests there are bushes (in different countries they are called maquis, shiblyak, scrub, chapparal, etc.), sometimes impenetrable, often thorny, with falling leaves or evergreen.

Savannas (in the Orinoco basin - llanos, in Brazil - campos) are a tropical type of herbaceous vegetation, distinguished from the steppes by the presence of xerophilous, usually low-growing, sparsely standing trees, sometimes reaching enormous sizes (baobab in Africa); That’s why savanna is sometimes called tropical forest-steppe.

Dry woodlands (caatinga in South America) are close to savannas, but they do not have a cereal layer; The trees here are far apart from each other and shed their leaves (except evergreens) during drought.

In equatorial countries, one of the most notable is the zone of moist equatorial forests, or gils. Its richness in vegetation (up to 40-45 thousand species) and fauna is explained not only by the abundance of heat and moisture, but also by the fact that it has existed without any special changes in the totality of its components at least since Tertiary time. In terms of richness and diversity, monsoon forests are quite close to the Gila, but unlike the Gila, they periodically shed their leaves.

The zonal structure of the Earth's vegetation cover is very clearly reflected in the fundamental classification developed by V.B. Sochava, who took into account the ecology of plants, the history of vegetation, its age and dynamics.

Conclusion

Natural zonation is one of the earliest patterns in science, ideas about which deepened and improved simultaneously with the development of geography. Zoning, the presence of natural belts, was found by Greek scientists of the 5th century on the Oikoumene, known at that time. BC, in particular Herodotus (485-425 BC).

The German naturalist A. Humboldt made a great contribution to the doctrine of natural zonality. There is a large literature about Humboldt as a scientist. But, perhaps, A.A. said about him better than others. Grigoriev - “The main feature of his works was that he considered every phenomenon of nature (and often human life) as part of a single whole, connected with the rest of the environment by a chain of causal dependencies; no less important was the fact that he was the first to use the comparative method and, describing this or that phenomenon of the country he was studying, sought to trace what forms it took in other similar parts of the globe. These ideas, the most fruitful of all ever expressed by geographers, formed the basis of modern regional geography and, at the same time, led Humboldt himself to the establishment of climatic and plant zones, both horizontal (on the plains) and vertical (in the mountains), to identifying differences between the climatic conditions of the western and eastern parts of the first of them and many other very important conclusions.”

A. Humboldt's zones are bioclimatic in content.

The zonal principle was used already in the early period of physical-geographical zoning of Russia, dating back to the second half of the 18th - early 19th centuries.

Modern ideas about geographic zoning are based on the works of V.V. Dokuchaeva. The main provisions on zonality as a universal law of nature were formulated in a condensed form at the very end of the 19th century. Zoning, according to V.V. Dokuchaev, manifests itself in all components of nature, in the mountains and on the plains. It finds its concrete expression in natural-historical zones, in the study of which the focus should be on soils and soils - “a mirror, a bright and completely truthful reflection” of the interacting components of nature. Wide recognition of the views of V.V. Dokuchaev was greatly promoted by the works of his numerous students - N.M. Sibirtseva, K.D. Glinka, A.N. Krasnova, G.I. Tanfilyeva and others.

Further successes in the development of natural zoning are associated with the names of L.S. Berg and A.A. Grigorieva. After extensive work L.S. Berg zones as landscape complexes have become a generally recognized geographical reality; Not a single regional study can do without analyzing them; they entered the conceptual apparatus of sciences far removed from geography.

A.A. Grigoriev is responsible for theoretical research on the causes and factors of geographic zoning. He briefly formulates the conclusions obtained as follows: “The basis for changes in the structure and development of the geographical environment (land) across belts, zones and subzones are, first of all, changes in the amount of heat as the most important energy factor, the amount of moisture, the ratio of the amount of heat and the amount of moisture.” A lot of work was done by A.A. Grigoriev on the characterization of the nature of the main geographical zones of land. At the center of these largely original characteristics are the physical and geographical processes that determine the landscapes of the belts and zones.

List of used literature

1.Gerenchuk K.I. General Geography: Textbook for Geography. specialist. un-tov / K.I. Gerenchuk, V.A. Bokov, I.G. Chervanev. - M.: Higher School, 1984. - 255 p.

2.Glazovskaya M.A. Geochemical foundations of typology and methods of research of natural landscapes / M.A. Glazovskaya. - M.: 1964. - 230 p.

.Glazovskaya M.A. General soil science and soil geography / M.A. Glazovskaya. - M.: 1981. - 400 p.

.Grigoriev A.A. Patterns of structure and development of the geographical environment / A.A. Grigoriev. - M.: 1966. - 382 p.

.Dokuchaev V.V. To the doctrine of natural zones: Horizontal and vertical soil zones / V.V. Dokuchaev. - St. Petersburg: Type. St. Petersburg city administration, 1899. - 28 p.

.Dokuchaev V.V. The doctrine of natural zones / V.V. Dokuchaev. - M.: Geographgiz, 1948. - 62 p.

.Kalesnik S.V. General geographical patterns of the earth: a textbook for geographical departments of universities / S.V. Kalesnik. - M.: Mysl, 1970. - 282 p.

.Milkov F.N. General Geography / F.N. Milkov. - M.: Higher School, 1990. - 336 p.

.Milkov, F.N. Physical geography: the study of landscape and geographic zoning. - Voronezh: VSU Publishing House, 1986. - 328 p.

.Savtsova T.M. General Geography: A Textbook for Students. universities, educational in specialty 032500 “Geography” / T.M. Savtsova. - M.: Academia, 2003. - 411 p.

.Seliverstov Yu.P. Geography: a textbook for students. universities, educational in specialty 012500 “Geography” / Yu.P. Seliverstov, A.A. Bobkov. - M.: Academia, 2004. - 302 p.

Tutoring

Need help studying a topic?

Our specialists will advise or provide tutoring services on topics that interest you.
Submit your application indicating the topic right now to find out about the possibility of obtaining a consultation.

If we summarize the above considerations, they can be reduced to the thesis: zonality acquires its specific content in the special conditions of the geographical envelope of the Earth.

Views