Part III. SYSTEMATIC DESCRIPTIONS OF SOILS
SOILS OF THE SUBTROPICAL WARM MOIST FOREST REGION (L)
Most characteristic soils The humid subtropics are yellow soils and red soils. This area occupies very limited space. Soils humid subtropics common in Western Transcaucasia and along the southeastern coast of the Black Sea within the Georgian SSR, as well as in mountainous areas Caucasus, on the slopes of the Talysh Mountains near the city of Lankaran (Azerbaijan SSR).
Strengthening natural regenerative systems, in addition to direct planting methods, can be achieved in several ways. The main goal is to add additional genetic material, adapted to the ecosystem, to provide a greater range of materials for multiple uses and to help the system regain its previous performance and resiliency. For example, existing distribution mechanisms can be used, such as planting a mixture of perennial legumes around degraded heads from which animals will spread naturally.
Rice. 13. Subtropical moderately warm areas: moist forest (L) and xerophytic forest (M). For a complete explanation of alphanumeric designations, see the legend to Fig. 5
The area of red soils and yellow soils within the Soviet Union is 0.6 million hectares. On the territory of the region, in the flat part, one province stands out - Colchis, since in Lankaran the flat territories occupy an insignificant area.
Nomadic pastoralists, supplied with seeds, will be able to replant forage shrubs and improve oasis systems with windbreaks or living fences composed of forage legumes. Where grazing pressure can be reduced and regeneration mechanisms strengthened, significant growth is likely to occur. A common way to approach this goal is to encourage herders to control their grazing. However, herders are usually more sensitive to the management of their grazing resources than outsiders, and if overgrazing occurs, it is because other conditions are making misuse of resources needed for survival.
Soils of a subtropical warm temperate forest region are being formed in humid and warm climates. The temperature of the coldest month is 0 - plus 6°C, and the warmest month is 21-24°C. The average annual air temperature is 13-15°C. The duration of the main growing season is 220-250 days, the frost-free period is 265-290 days. The sum of temperatures above 10° ranges from 2000 to 4400°. Precipitation varies between different years from 1200 to 2500 mm with evaporation 600-900 mm.
Animals can be used to regenerate rangeland if their use is carefully controlled. Cattle, sheep, goats and other livestock prefer several different feeds, so they can be raked or selectively sequential. Grazing animals may encourage dominance of nuisance species depending on how grazing occurs. This selectivity is especially noteworthy in some trees and shrubs. Improved grazing management cannot eliminate these nuisance species; therefore, it is necessary to find other ways to remove them.
The soil is wet subtropical regions are developing in dissected terrain and occur predominantly in the area of hilly foothills and low mountains with absolute mark up to 600 m above sea level. Red soils on the Black Sea coast occupy the slopes of the Adjara ridge with an elevation of 40 to 400 m above sea level. Subtropical podzolic-yellow soils are formed on leveled or slightly undulating ancient accumulative terraces. The highly dissected topography of these areas has great influence on the distribution of heat and moisture, causes soil erosion on steep slopes and waterlogging at the foot of the slopes and in depressions, and thus determines a wide variety of plant and soil covers.
The demands of urban areas also put pressure on rangelands. For example, many countries are encouraging the development of crop production in marginal areas to increase the amount of food needed to feed growing urban populations. It is necessary to find ways to improve the efficiency of food and feed production in areas where high productivity is possible, rather than expanding into marginal ones - these are where crop yields are low and grazing is more appropriate and reliable.
This report addresses issues of socioeconomic context, regional and site assessment, management approaches, and plant selection criteria for intensive rehabilitation efforts. The case studies contain additional information on these issues, as well as descriptions of projects that have succeeded through broad-based analysis and sensitivity to environmental and social context.
Most common breeds humid subtropical regions are products of weathering of igneous rocks: andesites, basalts, porphyritic tuffs and sedimentary tertiary deposits - clayey and sandy-clayey shales. In low areas, the soil-forming rocks are alluvial and deluvial-proluvial clay-sand and pebble-boulder deposits.
Subtropics and Mediterranean subtropics
Soil of the Mediterranean subtropics. Vegetation of the subtropics 1 Impact of climate on plants 2 Anthropogenic changes in vegetation. Our land is divided into different landscape areas. The classification is usually based on climatographic criteria, from which, for example, soil or hydrographic processes and changes depend. This division gave rise to broad parallel zones of the landscape, such as "tropics, subtropics, cool temperate, cold temperate or arctic, subpolar and polar latitudes." However, these zones are in turn divided into small areas, which are also called "subzones".
In warm and humid conditions climate weathering rocks occurs gradually and to great depth. The weathering crust undergoes great chemical changes at the same time. Red soils develop on a thick red-colored weathering crust up to 12 m deep. The less thick (2-3 m deep) yellow earth crust, which was formed as a result of weathering of sedimentary rocks - shales and sandstones, is also widespread. In the area where red soils are distributed on gentle foothills, so-called zebra clays are often found, which are distinguished by their heterogeneous, brownish-red color with whitish spots and stripes. Some researchers associate the formation of zebra clays with the weathering of pebble-boulder deposits.
The subtropical subzone is, for example, the Mediterranean subtropics, which, however, is considered the smallest subzone in the subtropical zone. It lies between 20 and 40° latitude in both northern and southern hemispheres and borders tropical dry zones and humid mid-latitudes. The differentiation of these zones is largely due to different climates. The tropics, for example, have a time-of-day climate, while the temperatures of the Mediterranean subtropics vary seasonally. The difference with the cold mid-latitudes is that in the subtropics, higher average temperatures are measured throughout the year, which are around 20 ° C. but found in the Mediterranean subtropics zone is not always the same triatomic condition on why the subzones can be divided into three climatic zones: dry subtropics, always wet subtropics and summer dry Mediterranean subtropics.
Large amounts of precipitation and abundance of heat contribute to the rapid growth and development of cultural and natural vegetation. Woody vegetation is represented by dense subtropical liana forests of the Pontic type. Their composition is dominated by hornbeam, beech, oak with an admixture of maple and chestnut, and in wetter places - alder. The thick undergrowth contains a lot of Pontian rhododendron, cherry laurel, and holly. The trees are intertwined with vines - ivy, clematis, wild grapes. Ferns grow abundantly under the canopy of subtropical forests and in forest clearings. Currently, this natural vegetation has been replaced by cultivated vegetation in many places.
My Homework should only apply to the last of the three climatic regions mentioned. Besides, no climate zone, which is distributed on such continents. All of these landscape areas are especially close to the coast, however. Penetrates the area on the Mediterranean Sea to the east and north. And although all areas belong to the summer dry subtropics, there are differences between them, especially in vegetation.
The Mediterranean covers the three continents of Europe, Africa and Asia. The total size is divided into "more than 1.35 million square kilometers of land and 2.5 million square kilometers covering the Mediterranean Sea" 3. European countries that are in or near this area are Portugal, Spain, San Marino, France, Italy and Vatican City, Croatia, Slovenia, Montenegro, Andorra, Monaco, Bosnia and Herzegovina, Greece, Albania, European part Türkiye, as well as the islands of Malta and Cyprus. The Asian Mediterranean region includes the Asian part of Turkey, Syria, Lebanon, Israel, Palestine and Jordan, and African countries The Mediterranean includes Egypt, Morocco, Tunisia, Libya and Algeria.
According to some scientists (B.B. Polynov, I.P. Gerasimov), the formation red weathered bark in the early stages of its formation occurred under alkaline conditions. Under the influence of biogenic carbon dioxide released during decomposition organic matter and respiration, as well as other waste products of microorganisms, the decomposition of aluminosilicates, the removal of alkalis, alkaline earths and silica and the relative accumulation of sesquioxides in the soil occurred. In red earth soils, some redistribution of sesquioxides is also observed, which is characteristic of the podzolic process. Further research revealed that at the present stage of development of red soils, calcium is most vigorously removed and, to a lesser extent, magnesium and silicic acid. The filtrate from under red soils contains very few sesquioxides, which indicates their fixation in the soil and the absence of noticeable removal. The accumulation of iron sesquioxides determines the color of red soils in different shades of red and yellow.
Drawing not included in this excerpt. Figure 1: Map Mediterranean Sea with the border line. A precise classification of the Mediterranean is not possible since, for example, in the south the desert climate also moves towards the coast and thus can create an overlap with the subtropical climate, making clear demarcation impossible. However, Sahara and Syrian desert often called cornerstones in the east, Lisbon in the west and the Alps in Veneto in the north. Vegetation can be used as a boundary line, such as the olive tree, which is considered a typical plant of the Mediterranean Sea.
Zheltozems According to the conditions of formation, they are very close to red soils. Unlike red soils, which form on the red earth weathering crust of basic igneous rocks, yellow soils form on acidic weathering products of shales and other metamorphic and sedimentary rocks, both dense and loose (loamy and clayey). Zheltozems, therefore, represent a more weakly expressed stage of the red earth process.
Therefore, the division of the Mediterranean Sea cannot be based on the classification of countries or vegetation that occurs, but only on the “landscapes shaped by the Mediterranean climate” 4, which can vary in size from one country to another. The climate of the Mediterranean subtropics is the least represented in the world and is especially striking in its annual course, since here, unlike the humid subtropics, the maximum temperature and precipitation do not coincide. There is "an alternating climate with two glory years following each other rather sharply."
As stated above, soil formation process occurs initially under alkaline conditions. Then, due to the removal of alkalis and alkaline soils, it is replaced by an acidic environment and podzolization of red and yellow soils occurs under the forest. But signs of podzolization do not always appear in these soils. The weak manifestation of the podzol formation process in red soils is associated with a large number bases formed during the decomposition of organic matter that neutralize acidic products. The degree of podzolization is also determined by the nature of the soil-forming rock. The degree of podzolization increases with temporary waterlogging, which is often observed on low relief elements.
The climate is determined by the location of the intrazonal convergence zone. For these areas high pressure characterized by shining weather, drought and long sundial, similar to the climate prevailing in deserts. Summer warming is caused by proximity to the sea and relatively low temperatures coastal waters. Due to persistent areas of high pressure, air exchange is unlikely and may result in temporary cooling.
This winter climate can be compared with the winter climate of our latitudes. So you can divide the climate of the Mediterranean subtropics into a summer dry season and a winter rainy season, which is why the climate is also called winter monsoon. Due to the difference in air pressure between land and sea in winter and spring, regional winds are typical in the Mediterranean region. They come either from the north or south, but are called proper names, and not by main points.
The podzolic process is combined in red-earth and yellow-earth soils with the turf process, as a result of which the accumulation of humus. This combination of the podzolic process with a significant accumulation of humic substances in the soil is explained by the peculiarities of the biological cycle of substances, and primarily by the large amount of plant residues entering the soil annually and ash elements formed during the decomposition of organic matter.
Preliminary assessment of the sustainability of agroecological supply in the subtropical Central High Plateau of Mexico. Preliminary assessment of the sustainability of agroecological supply in the subtropical central highlands of Mexico. Autonomous University of the State of Mexico.
IN lately sustainability assessment using systems approaches has attracted attention given its potential as a decision-making tool. On the other hand, experimental university farms must perform research, teaching, and extension functions, as well as be environmentally and economically sustainable. A university farm located in the subtropical Central Highlands of Mexico was evaluated. In the first phase of the study, characterization, diagnosis, and initial assessment were performed.
Within this soil-geographical region, following types and soil subtypes:
- Part I. Properties, classification, distribution of soils
- Definition of the concept “soil”, its place in nature and life
- Part 2. Soil key
- Part 3. Systematic descriptions of soils
- Analysis of the soil cover of the coastal zone of Lake Bolshaya Lebedinoye
- Soils, vegetation and fauna of Russia (general overview)
See images and descriptions of others natural objects Russia and neighboring countries - minerals and rocks, soils, fungi, algae, lichens, leafy mosses, trees, shrubs, shrubs and lianas, herbaceous plants (flowers),
The main problems were identified and prioritized, for which proposals for solutions were obtained within the framework of the agroecological approach. Subsequently, 14 environmental, economic and social indicators were selected and measured. The results show low values in most indicators as a result of low integration between subsystems and lack of resource conservation practices. The methodology used was useful in enhancing understanding of ecosystem processes and developing methods and alternative solutions.
IN subtropical zone The following main groups of soils are distinguished
· Soils rain forests
Soils of dry forests and shrubs
Dry subtropical steppes and low-grass semisavannas
Red soils and yellow soils of the humid subtropics. Widely developed in eastern Asia(China, Japan) to the southeast. USA - Florida and southern states. On the Black Sea coast (Adjara), Caspian Sea (Lepkoran). Climate. Precipitation ranges from 1 to 3 thousand mm per year, mild winters and moderately hot summers. Average annual t 14 0 C.
Key words: agroecology; diagnostics; grade; University Ranch; sustainability. Sustainability assessment using systems approaches has received attention due to its potential as a decision-making tool. In addition, university experimental farms must adhere to the core university functions of research, teaching and extension, and be environmentally and economically sustainable. This work assessed a university located in the subtropical Central Highlands of Mexico.
The first stage of the study involved characterization, diagnosis and initial assessment, in which the main problems of the system were identified and prioritized, and solutions from an agroecological approach were proposed for each of them. Subsequently, 14 environmental, economic and social development. The results show low levels in most indicators as a result of low integration between subsystems and lack of resource conservation practices.
The vegetation is represented by hornbeam, oak, chestnut, and juniper. Biomass subtropical forests exceeds 4000 c. with hectares
The soil-forming rocks of the red soils are the weathering crust, and there is an accumulation of Al and Fe enriched in kaolinite. How the color of the soil is determined.
Classification of red soils. Typical (occupying sloping slopes) and podzolized (developing on gentle slopes, available horizon A 2 contains humus from 4 to 9%, pH 4.2-4.5).
Yellow soils are formed in drier conditions and have a pale yellow color. IN rural farming These soils are used for growing tea, citrus fruits, grapes, fruits, and vegetables.
Brunozems wet subtropical soil. These soils are close to chernozem-like. They are found in North and South America within the humid subtropical pampa. They develop on basaltic metamorphic and weathered rocks. The relief is flat. The climate is warm and evenly humidified (500-1400 mm per year). Brunozems are divided into typical, leached, and reddish.
Brown soils of dry subtropical forests
And bushes.
In a variable-humid subtropical climate, brown soils form under dry forests and shrubs (oak, laurel, tree-like juniper, hawthorn). Precipitation (600-700 mm per year) falls from November to March. Soil-forming rocks are represented by Quaternary sediments, eluvium, limestone and dolomite.
Thickness A 1 – 60-70 cm of humus contains 4-6%.
Brown soils are divided into 3 subtypes
1. Brown leached ones boil below A 1 at a depth of 80-110 cm, develop in the most humid areas.
2. Brown typical - boil in horizon B.
3. Brown carbonate - characterized by carbonate content throughout the entire profile. They are confined to the most arid zones. Brown soils are characterized by high fertility. They grow grapes, fruit trees, and olives.
Gray soils of dry subtropics are presented in the foothills of the ridges Central Asia. The annual precipitation is 500-600 mm per year in summer t 0 reaches 30 0 C, in winter 1-2 0 C. Vegetation defines subtropical steppes and low-grass semi-savannas (cereals, giant umbellifers - ferula, ephemeral bluegrass, poppies, tulips).
The soil-forming rocks are loess. Cotton, rice, melons, and grapes are grown on irrigated soils.
Soils tropical zone . In this belt, the most common are red-yellow ferralitic soils of permanently humid tropical forests to red-brown soils of middle savannas and soils of tropical deserts. The soils of permanently humid tropical forests are colored red and yellow. They are located in South America, Africa, Madagascar, Ceylon and Australia.
The climate is characteristic high temperatures and large amounts of precipitation (more than 10,000 mm). Rainforests have huge biomass (5000 centners per hectare to 17000 centners per hectare). Most The litter is destroyed due to the intense destruction of microorganisms.
Soil-forming rocks are eruptive, effusive or sedimentary-metomorphic. Iron hydroxides are formed during soil formation. Humus content from 3-10% pH from 5.5 to 6.5. in the area of humid forests large area occupy the soils of tropical swamps.
Soils of tall grass savannas. Characteristic feature is the alternation of rainy and dry periods with an average annual amount of 1000-1500 mm. Red and yellow soils are formed on ancient weathering ridges. They are highly enriched with hydroxides. Humus content is 2-4%. These soils are quite fertile and are used for growing sugar cane, coffee, citrus fruits, and many crops.
Lecture 15 (2 hours)
Patterns of spatial distribution of soils
On the continents.
Soil geography is a field of soil science that studies general patterns soil distribution and soil cover of individual regions. Dokuchaev identified five world zones
1. Boreal
3. Black soil steppes
4. Aerial
5. Lateritic
In 1906, K.D. Glinka compiled the first soil map peace, which was demonstrated in 1927 at International Congress soil scientists in Washington. The combination of all materials across continents made it possible to create in 1956 new map world on a scale of 1:20000000 by a team of authors led by I.P. Gerasimov. Continental maps and a general summary map were compiled using a unified system and linked to the main physiographic components. Zonal soils are confined to one or another geographical zone: polar, boreal, subboreal, subtropical and tropical equatorial. In total, 31 types of zonal and 34 types of hydrozonal soils were identified, occupying lowland areas and 23 types of soils in mountainous areas.
The soil cover of different continents varies markedly. In Eurasia it is very diverse. In the northern part of Europe, soddy-podzolic soils predominate, and on the Scandinavian Peninsula and the polar islands arctic and tundra soils, and to the south there are brown soils. IN Western Siberia and Kazakhstan, Eastern Siberia soil zones change from forest-tundra to gray-brown, and in the territory of the D. Eastern part there are brown forest soils. Central Asia bears the soil cover of subtropical desert and desert-steppe soils. In the area of southern China, subtropical red soils and yellow soils and red ferralitic tropical soils with massifs of black soils are developed.
In Australia, red and yellow ferralitic soils are also common in the northern part; to the south they are replaced by red and red-brown soils of dry forests and savannas. Desert soils are located in the center of the continent (red deserts). In the eastern part of the continent, in the oceanic zone, red soils of tropical and subtropical forests have formed. In the mountains eastern Australia there are brown forests, western brown soils of dry forests and shrubs.
North America has a certain similarity in soil cover With northern part Eurasia. Arctic and tundra soils formed in the Arctic cover, and in Alaska - turf soils similar to Kamchatka. The northern part of the plains is covered with soddy-podzolic soils, and brown forest soils are found in the Appalachian region. West Coast The continent is represented by mountain-podzolic in the north and mountain-chernozem, as well as mountain-brown in the south.
In the south and central America Tropical ferralitic soils predominate. In areas of dry steppes, black and reddish-black soils are common. Mountain desert soils are developed in the mountain ranges. The Amazon and Orinoco basins have an abundance of marsh soils, while the Pacific coast of Peru and Chile is home to deserts with nitrate salt marshes.
Lecture 16 (2 hours)
Land resources peace
Among the main resources of the biosphere that are actively used by humans (water, air, vegetation, fauna), soil takes the leading place.
Land resources occupy about 1/3 of the planet's surface, almost 14.9 billion hectares, and without Antarctica and Greenland - 13.4 billion hectares.
10% - occupied by glaciers
15.5% - deserts, rocks, coastal sands
7.5% - tundra and swamps
2% - cities, mines, roads
3% - lands spoiled by man (bad land)
As a result, agricultural land accounts for only 11% or 1.5 billion hectares.
There is a trend towards a decrease in the area of agricultural land category. At the same time, the availability (in terms of 1 person) of arable land and forest land is decreasing.
Almost 1/3 (145 million hectares or 31%) is occupied by mountainous lands unsuitable for agriculture (Perinees, Carpathians, Alps, etc.).
More than 50 million hectares of land are waterlogged and require drainage reclamation; about 20 million hectares require irrigation; 83 million hectares require chemical reclamation.
One of the main reasons for changes in land use areas in agriculture is desertification. This process threatens the entire landmass and 20% of the population in 100 countries.
It is estimated that in the coming years, annual losses from desertification will reach 26 billion dollars.
Currently, food production on average per person requires 0.3 - 0.5 hectares of land. On at the moment The planet's population is more than 6.5 billion people.
On our planet there is significant amount arable land. Their total area is 3 billion 190 million hectares. This means that the area of arable land can be doubled. The most commonly used soils are ferrallitic soils, chernozems, desertified soils, soddy-podzolic soils, and alluvial soils.
Land use in the cold zone
From arctic deserts up to mid-taiga forests, the limiting factor is heat deficiency. Livestock farming is of a focal nature. From crop production, it is possible to grow early ripening potatoes and cabbage in the forest-tundra.
