Where the tropical grow. Presentation on the topic: "What is a rainforest? A rainforest is a very special forest. In such a forest it is always very humid and warm. It is very dense, often intertwining." Download for free and without registration. How to protect the tropical
Tropical rain forests are common in the equatorial belt, north of the equator to 25 ° N latitude. and south to 30 ° S latitude.
Rainforest america
In America, they grow from the coast of the Gulf of Mexico in Mexico and southern Florida (USA), occupy the Yucatan Peninsula, most of Central America, and the West Indies. South American tropical rain forests (also called selva or gilea) are located in the Amazon River basin (the Amazon rainforest is the largest rain forest), in the north of South America, and are common on the Atlantic coast of Brazil (Atlantic Forest).
Rainforests of africa
In Africa, they grow in the west of the equatorial part from the coast of the Gulf of Guinea to the Congo Basin (including the Atlantic Equatorial Coastal Forests), and in Madagascar.
Rainforest areas
In addition, tropical rainforests are found in Asia from the south of India, many areas of Southeast Asia from Myanmar and southern China, and extend to the east of Queensland in Australia, capturing the islands of Indonesia and New Guinea. They also grow on the islands of the Pacific Ocean.
Plain forests in the mountains
In the mountains, lowland rainforests grow up to an altitude of 800 m above sea level. Above, the species composition becomes poorer, the structure of the forest changes. Since the tropical mountain evergreen forest grows in the fog condensation zone, it is called the fog forest.
The most beautiful rainforests in the world
Forest in the Congo Basin
The second largest rainforest on the planet. It covers the territory of Central Africa, Cameroon, Republic of the Congo, etc. This forest includes 600 different types plants and 10,000 animal species. Due to the massive felling of green spaces, it was threatened with extinction, but now the world community is making every effort to save it.
Mau forest
It is considered the largest in the Rift Valley. It covers an area of 670,000 hectares and is the largest catchment area in Kenya. The Mau Rainforest provides fresh, clean and healthy water to the Lake Victoria river. Some people tried to cut it down because of the incredibly fertile soil, but the Kenyan government stopped this sacrilege in order to preserve the beauty and nature of the amazing forest.
Valdivian rainforest
Located in the south of South America. It is included in the list of the world's biological diversity. This is because more than 90% of the plants and 70% of the animals living here are truly rare and unique, and it is rather difficult to find them anywhere else. This is the reason why the forest is considered not only one of the most beautiful, but also one of the most valuable on the planet.
Sumatra forest
Located on the island of the same name, which is the largest in Indonesia. This beautiful forest is famous for many unique animals and plants. And its territory allowed it to take the sixth place in the world in terms of area among tropical forests. Unfortunately, the forest also faced human invasion as the Indonesians began the practice of illegal tree felling. But the government is making every effort to preserve the miracle of nature.
Kelp forest
It is found in Australia and is home to many animals, especially marine life. It is also the main source of seaweed, which can reach 80 meters in height. It is important that in the case of this forest, there is practically no deforestation, which is very good for the creatures living in it.
Colombian rainforest
Growing in South America, is home to real tropical trees, the height of which is known all over the world. Hundreds and thousands of different trees and plants can be found in this magnificent forest. The forest is best known for plantations of palm trees and cocaine. But the government is doing everything it can to protect the forest from settlement, deforestation and other actions that are contrary to the law.
A tropical forest- a forest distributed in the tropical, equatorial and subequatorial zones between 25 ° N. NS. and 30 ° S. NS. Rainforests are found in a wide belt that surrounds the Earth at the equator and is torn apart only by oceans and mountains.
The general circulation of the atmosphere occurs from a zone of high atmospheric pressure in the tropics to a zone of low pressure in the equator, and evaporated moisture is transported in the same direction. This leads to the existence of a humid equatorial belt and a dry tropical one. Between them is the subequatorial belt, in which moisture depends on the direction of the wind (monsoon), which depends on the season.
The vegetation of tropical forests is very diverse, depending mainly on the amount of precipitation and its distribution over the seasons. In the case of abundant (more than 2000 mm) and their more or less uniform distribution, humid tropical evergreen forests.
As you move away from the equator, forests appear, in which moisture depends on the season: the rainy period is replaced by a dry one. This is - winter-green variably humid tropical forests with leaves falling off during a drought. Further, these forests are replaced savannah forests.
At the same time, in Africa and South America, monsoon and equatorial forests are replaced by savanna forests from west to east. In an even more arid climate, forest stands are thinned, savanna forests are replaced by xerophilic thorny forests and thickets of shrubs.
Humid tropical forests are characterized by the greatest abundance of flora on Earth (over 4/5 of all plant species), the predominance of woody species in it (about 70% of higher plants), and their diversity (from 40 to 100 species per hectare). Unlike temperate forests, tropical forests rarely have two trees of the same species standing side by side.
Distribution of tropical forests
It will immediately become clear where the rainforests grow, if we explain that they, as it were, "encircle" the planet along the Equator. They are located in the humid equatorial, dry tropical, temperate subequatorial zones, representing a clear line, interrupted only by mountains and oceans.
Vegetation changes depending on the air temperature and the amount of precipitation. Rainy areas are covered with evergreen flora, drier regions are characterized by deciduous plants, followed by savanna forests.
In both South America and Africa, there are monsoon forests in the west, savanna forests in the east, and equatorial forests in the middle.
Rainforest map
Forest levels
The warm, humid climate of the rainforest provides an ideal environment for an immense abundance of amazing plant life. The rainforest is divided into several tiers, which are characterized by their own flora and fauna.
The tallest trees in the tropics receive the most sunlight. This includes, for example, a cotton tree.
Second tier- dome. The level of the crowns is considered the most diverse, about 25% of all insect species live here. It is the habitat for half of the rainforest wildlife -, and. This includes trees below 50 m in height with wide leaves, hiding sunlight from the lower floors.
Scientists agree that 40% of all plant species on the planet are located on this tier, although it has not been fully studied. These are philodendron, poisonous strychnos and rattan palms. Vines usually stretch along them to the sun.
Third tier inhabited by shrubs, ferns and other shade-tolerant species.
The last tier, the lower one, usually dark and humid, since the sun's rays hardly penetrate here. It consists of quail foliage, mushrooms and lichens, as well as young growth of plants of higher tiers.
Rainforest classification
The main groups of rainforest formations are rain, or wet, and seasonal.
Tropical rainforest
Distributed in the equatorial belt, they are characterized by abundant precipitation (2000-7000 mm, sometimes even up to 12000 mm) and their relatively uniform distribution throughout the year at a practically unchanged average air temperature (24-28 ° C). Main regions of distribution: South America, Central Africa, Southeast Asia and Australia. Tropical rainforests are considered the center of evolutionary activity, a place where new species form, spreading to other regions.
They are the most ancient type of vegetation, practically unchanged since the Tertiary period.
The main groups of tropical rainforests are humid evergreen mountain forests, tropical swamp forests, rainforests, tropical lowland forests, mangroves.
Mangroves common in the tidal zone of tropical coasts and, if warm currents favor this, then along the coast in a temperate climatic zone. They grow in areas free of water at low tide and flooded at high tide.
Mangrove forest
Tropical mountain evergreen forests usually grow above 1500-1800 m, where air temperatures drop to 10-12 ° and below, which prevents many organisms from developing. The relative preservation of these forests, which are of significant importance in stabilization natural conditions(water protection, anti-erosion, etc.), contributes to their low economic value associated with the difficulties of development under the conditions of the relief.
Swamp forests occupy a noticeably smaller area than non-flooded plain forests. They are similar in their properties, although they have enough differences. Distributed in the same plains, they create a landscape mosaic of tropical forests.
Seasonal rainforests
They grow in areas where, despite good moisture (2500-3000 mm), there is a dry period. The amount of precipitation and the duration of the dry period in different forests is not the same, among them there are
- evergreen seasonal forests(e.g. Australian eucalyptus),
- semi-evergreen forests(deciduous species are presented in the upper tier, in the lower tier - evergreens)
- light sparse forests(The floristic composition is poor, it can be represented by one breed).
Deciduous seasonal rainforests are divided into monsoon forests and savanna forests.
Monsoon forests grow in the monsoon area, the dry period lasts about 4-5 months. They are located in South and Southeast Asia, including Hindustan, Indochina, the Malacca Peninsula, in the northeast of Java. Forests of this type also grow in the West Indies and Central America (Trinidad Island, Costa Rica) and West Africa.
In monsoon forests, three main groups of plant communities can be distinguished.
- The mixed forests are dominated by terminalia, dalbergia, albicia and others, and the undergrowth consists of bamboos and small palms.
- In teak forests - teak tree (large tectone), deciduous Acacia lencophloea and Albizzia procera and evergreen Butea frondosa, Scheichera trijuda, etc.
- Forests from Shoreya gigantic, undergrowth from Terminalia, Sterculia, etc.
Ebony trees and Indian laurel grow in India. Lianas and epiphytes, although not as numerous as in evergreens, are more numerous than in savanna forests. The forest canopy in monsoon forests is sparse compared to humid tropical forests, so the grass cover in them is closed. The grasses are mostly annual, in the driest areas wild sugarcane predominates.
Triplochiton (Triplochiton scleroxylon) is especially characteristic of the upper layer of forests of this type in West Africa.
Savannah forests distributed in tropical regions with a pronounced dry season and less annual precipitation than in the belt of closed forests. Distributed over most of Cuba and other islands of the Caribbean, in many regions of South America, East and Central Africa, and here and there in India, China and Australia.
For savannah forests, deciduous trees from the legume family are typical, the crown of which is usually flat umbrella-shaped. Trees are up to 18 m high. In places where the trees are 3-4.5 m high, during the rainy season, the grasses may be higher than the trees. Grains form the basis of the herbaceous cover.
In thorny xerophilous forests, there are trees with scaly leaves and shrubs with green stems without leaves. Plants are often covered with thorns, and stem and root tissues are capable of storing water.
Rainforest herbs
Where tropical forests grow, two groups of grasses prevail: shade-loving and shade-tolerant. The former prefer to grow in significantly shaded areas, while the latter are able to develop normally under a closed forest canopy. It should be borne in mind that even in the daytime twilight reigns here, since the sun's rays are unable to break through the crowns of numerous trees.
In the American tropics, you can find tinama - a poorly flying bird with short but very strong legs.
Well, how can you not remember the bright, funny and talkative, without which the tropics are not tropics. In addition, variegated pigeons, trogons, woodpeckers, flycatchers, hornbills and others live on the equator.
In terms of the number of species, tropical forests significantly exceed the forests of temperate and cold countries, the fauna of tropical rain forests is the richest, however, the number of representatives of each individual species is small in them.
As a rule, tropical forest animals live in trees and in crowns. Representatives of mammals are monkeys, flying squirrels, sloths, spiny-tailed squirrels, needle-hairs, some insectivores, carnivores, and so on.
Birds are represented by parrots, woodpeckers, toucans, hummingbirds, craxes, hoatsins and others; examples of reptiles are chameleons, tree snakes, some geckos, iguanas, agamas; amphibians - some frogs. Many reptiles are poisonous.
In humid tropical forests, due to a lack of light, the undergrowth and grass cover are poor, so there are few terrestrial species in them. They are represented by tapirs, rhinos, bakers, hippos. The habitat of large mammals, including elephants, giraffes, buffaloes, is the seasonal rainforest.
Invertebrates are very diverse, they can be quite large, stand out for the richness of shapes and colors, among them ants, centipedes, butterflies and others.
Ecology
Tropical forests are extremely important for the biosphere of the planet; they are the habitat of almost half of all biological species inhabiting it, over 80% of all plant species. The area of tropical forests is half of the forest area of the Earth. They produce 69% of all net primary forest production in the world. Rainforests evaporate about 9% of the water entering the atmosphere.
Despite the high biological productivity (up to 3500 g / m² per year) and large leaf litter, the stock of litter in them is much less than in temperate forests. This is due to both the intensity of leaching in rain forests and the overall intensity of decomposition, with fungi and termites processing over 90% of the annual increase in plant matter. The rest is eaten by herbivores, which, in turn, serve as a food source for predators.
Half of the primary rainforests have disappeared - either secondary forests have grown, or grassy communities remain, which may turn into deserts. The greatest concern is the decline in rainforest rainforests. Ecosystems of the seasonally humid tropics have adapted to both seasonal changes and interannual differences in the duration of dry and wet periods; therefore, they are more resistant to anthropogenic impacts. The process is aggravated by the fact that during deforestation in just 1-2 years, nutrients are washed out from the soil into the subsoil.
The main reasons for the decline in tropical forest area are:
- slash and burn agriculture,
- burning forests for pastures,
- logging.
Many international organizations, for example IUCN, UN FAO, UNEP, are aware of the importance of tropical forests for the planet's biosphere and contribute to their conservation. About 40 million hectares of protected areas have been created here, including the Salonga and Maiko National Parks (Zaire); Jau, Amazonian (Brazil); Manu (Peru), Canaima (Venezuela). It is believed that in order to preserve tropical forest ecosystems, protected areas should cover at least 10% of the forest area.
Tropical forests are the "lungs" of our planet, the most precious treasure, "the big pharmacy of the Earth." For many years, it was believed that they produce colossal amounts of oxygen, but this turned out to be not the case, but the humid climate promotes impeccable air filtration and purification of pollution. A lot is growing in this zone. medicinal plants, which have found application in folk and official medicine. Where a huge number of birds, predators, artiodactyls, amphibians live, they all somehow get along on the same territory, surprising travelers with their large numbers.
Distribution of tropical forests
It will immediately become clear where the rainforests grow, if we explain that they seem to "encircle" the planet along the Equator. They are located in the humid equatorial, dry tropical, temperate, representing a clear line, interrupted only by mountains and oceans. Vegetation changes depending on the air temperature and the amount of precipitation. Rainy areas are covered with evergreen flora, drier regions are characterized by deciduous plants, followed by savanna forests. In both South America and Africa, there are monsoon forests in the west, savanna forests in the east, and equatorial forests in the middle.
Forest levels
The description of the rainforest will be clearer if it is divided into tiers. There are four main levels. The topmost one is evergreen trees up to 70 m tall, they have green caps mainly only on top, but below there are bare trunks. These giants can easily withstand hurricanes, temperature drops, sheltering the rest of the tiers from bad weather. The main hosts here are eagles, butterflies, bats. Further there is a forest canopy consisting of 45-meter trees. The level of the crowns is considered the most diverse, about 25% of all insect species live here. Scientists agree that 40% of all plant species on the planet are located on this tier, although it has not been fully studied.
This is followed by the middle level, called the undergrowth, where snakes, birds, lizards live, the number of insects is also huge. Remains of animals and decaying plants are found on the layer of the forest floor. This stratification is more common in the humid tropics. For example, selva - the forests of South America - is divided into only three levels. The first is grass, low plants, ferns, the second is reeds, low shrubs, young trees, the third is 40-meter trees.
The dominant species of flora and fauna depend on where tropical forests grow. For example, mangroves are common in equatorial and tropical latitudes in the tidal zones of the sea coasts. Plants grow here that are accustomed to do without oxygen and feel great in salty soil. Their roots create an excellent habitat for oysters, crustaceans, and commercial fish species. On the slopes of the mountains, in the area of fog condensation, moss or fog forests grow, characterized by low night temperatures.
The arid regions are dominated by savannah and rainforest, but dry. The plants here are evergreen, but xeromorphic and undersized. In the regions of the equatorial and tropical zones with variable climates, variable moist forests grow, characterized by deciduous crowns and a small number of lianas and epiphytes. They are found in South America, Africa, Sri Lanka, India and Indochina.
Rainforest climate
In humid tropical forests, the air temperature ranges from 20 ° C to 35 ° C, it rains here almost daily, so the humidity is kept at 80%, and in some regions it reaches 100%. In the subtropics there is no pronounced seasonality, the temperature is characterized by stability. On the mountain slopes, where fogs are observed, it is warm during the day, and at night a sharp cooling to 0 ° C is possible. The climate of the rainforest varies depending on the belt. In the tropics heat and low humidity, there is a lot of moisture at the equator and very hot, and in the subequatorial belt, the weather depends on the monsoons.
Trees of the tropics
Trees in tropical rainforest differ significantly from trees in the temperate zone. The peculiarity of their development is influenced by weather conditions, because there is no seasonality at the equator, it rains almost daily, and the air temperature is 25-35 ° С. If in Russia giants grow in several centuries, then 10-15 years are enough there. Each type of tree sheds its leaves in a strictly defined period, it can be once every six months, once every 2-3 years. They also bloom when they want, many representatives of the flora delight with flowers once a decade. The trees have mostly large leathery leaves that are strong enough to withstand heavy torrents of rain. More than 600 species of bamboo, chocolate cola, marang, jackfruit, mango, etc. grow in the tropics.
Exotic shrubs
The question of whether there is a shrub layer in tropical forests remains rather controversial. It exists in the subtropical and temperate zones, but not in the equatorial zone. Of course, there are representatives of shrubs there, but there are very few of them and they will not create their own level. Together with them, herbaceous phanerophytes grow, preserving the trunk from one to several years, and undersized trees. This includes representatives of the scitamines, maraths, and bananas families. Most of the shrubs are dicotyledonous, their leaves are large, but tender.
Rainforest herbs
The virgin forests are inhabited by incredibly beautiful, bright, with an unusual appearance of birds. Each separate part light boasts some kind of bird of its own. For example, in the tropics of Asia, there are turachi, appearance they resemble partridges, only slightly larger. They run fast, so in case of danger they do not take off, but flee with all their might. Shrub chickens, pheasants, and regal peacocks also live in the forests. In the American tropics, you can find tinama - a poorly flying bird with short but very strong legs. Well, how can you not remember the bright, funny and talkative parrots, without which the tropics are not tropics. In addition, variegated pigeons, trogons, woodpeckers, flycatchers, hornbills live on the equator. In the forests of the Amazon there are hummingbirds, tanagers, rocky cockerels, cotings and many others.
Animals
The fauna of tropical forests is striking in its diversity and richness of species. The largest number is represented by a group of monkeys living high in trees and in impenetrable thickets. The most interesting of them are cebids, marmosets and arachnids of the family. Igruniforms are characterized by a very small size, in length they reach no more than 15 cm, cebids boast a long tail with which they catch on branches, and arachnid monkeys have flexible and long limbs.
But the fauna of tropical forests is not limited to monkeys alone; anteaters, sloths, porcupines also live here. Among predators, representatives of felines predominate - jaguars, jaguarundi, ocelots, panthers, from the canine family - bush dogs. There are also ungulates - tapirs, spoke-horned deer. Rainforests are also rich in rodents - possums, marsupial rats, bats, agouti.
Amphibians of the tropics
Large and reptiles are also characteristic of the rainforest. Photos of exotic snakes, frogs, crocodiles, chameleons, lizards are no longer considered a rarity. Amphibians are found in all parts of the world, but they are most abundant in tropical rainforests, as they are attracted by heat and moisture. At the equator, they live not only in water, but also in trees, in the axils of leaves, in hollows. Salamanders live in the tropics, there are many poisonous snakes, water anacondas and land boa constrictors are widespread.
Insects
Looking at what animals live in the rainforest, it can be assumed that insects are no less bright, unusual and dangerous here. These small creatures of the tropics are attracted by the warmth, high humidity and a wide variety of food - animal remains, numerous plants. At the equator, you can find bees and wasps that are familiar to us, only here they are larger in size and bright, shiny color. Among them there are representatives with long legs, blue wings and a large body, they are able to tame large beetles and spiders. Bloated trunks are found on many shrubs - these are ant nests. Ants in the tropics protect plants by eating leaf-eating insects.
Beetles do not play a significant role in the life of tropical forests, but every traveler will be fascinated by their diversity and variegation. These insects are a natural decoration of this God-forsaken area. Of course, one cannot help but remember the tropical butterflies, only in South America there are more than 700 species of these beautiful creatures. Animals and plants of tropical forests represent a special world unknown to people. Researchers annually make their way deep into the thickets in order to lift the veil of secrets that this area keeps, to find new representatives of flora and fauna.
I recently watched a program that changed the way I think about forests. I used to think that the largest area covered with forests is taiga and forest-tundra. It turns out that even more of the Earth is occupied by the tropics.
What is this rainforest
Rainforests are made up of a rich variety of vegetation. The tropics are always dense, and the plants grow in tiers:
- giant trees up to 60 meters high. Their foliage is tough and rough, capable of retaining moisture. The crowns of such trees do not close;
- trees up to 30 m high, which have closed crowns among themselves. There are many epiphytic plants in this layer;
- shrubs and grass.
Each tier has its own fauna.
Where do rainforests grow?
Rainforests are humid and seasonal. Depending on their type, the distribution area changes.
Evergreen and swampy rainforests can be found in Australia, South America, Central Africa.
The rainforests are incredibly beautiful and are the birthplace of new plant species. There is a huge abundance of myrtle, majestic dipterocarp, palm species.
Mountain rainforests are among the oldest on the planet. Moreover, they play the greatest role for the environment. The good news is that for millions of years these forests have retained their integrity. This is due to the fact that mountain forests are almost never used in economic activity human, since the topography of the soil is very difficult to access.
Seasonal rainforests differ from humid ones in that it rains here for only a few months, the rest of the periods are relatively dry.
Both evergreen and deciduous tree species grow in the seasonal tropics. Monsoon forests grow in Central America, West India and West Africa. Winds and high humidity prevail here in summer.
Savannah rainforests love an arid climate, so they grow well on the islands of the Caribbean, China and Australia, East Africa and some dry regions of India.
On the this moment some rainforests are beginning to be destroyed by farming and burning.
abstract
by geography
on the topic
"Rainforests".
Completed: student 6 "A" class C.O. No. 1430
Cauldron of Light
- Introduction …………………… 3p.
- Main part …………… .4-6 p.
- Conclusion ………………… 7p.
- References ……… ..8 p.
- Appendix ………………… 9-10 pp.
Introduction.
I was interested in rainforests, so I decided to write this essay. In it I will talk about animals living in the tropics. I will also talk about tropical plants. In my abstract, of course, there will be pictures, because pictures are visual material. What is the tropics? natural area in which plants and animals live and grow that are not elsewhere. But my essay will tell you more about them. And I hope that he will explain it clearly. So, we begin:
Rainforests.
Tropical forests (from the Greek tropikos (kyklos) turning, circle), parallels with latitudes 23 ° 07 "- the general name for forests distributed in the equatorial, subequatorial and tropical zones of the Earth. Depending on the degree and rhythms of moisture, tropical forests are very diverse. The constantly humid equatorial belt is dominated by dense forests with a variety of plant species. These are gile forests in the Amazon basin in South America, Congo in Africa and the islands of Indonesia. monsoon areas and suhotropic when forest transitions to savannah.In the coastal strip of the tropics with a monsoon climate - mangrove vegetation.On the slopes of the Andes, where condensation fogs are common, giley forests turn into a kind of mixed: evergreen, broad-leaved and deciduous foggy forests.
Among the dry forests, the most interesting are eucalyptus forests, which are found only in the east of Australia. Eucalyptus trees are usually very tall trees with sparse, almost shade-free crowns. Every year, eucalyptus trees shed their bark so that it does not interfere with their growth. The high height of trees is not associated with the pursuit of light - in this way they are saved from forest fires. The undergrowth often burns out, and eucalyptus trees, as a rule, survive: after all, their crown is high, and the dense bark does not burn well. Precipitation in eucalyptus forests falls up to 1000 mm per year, but due to the heat a lot of moisture evaporates, so there is not enough water for active growth. You have to save it and at the same time: overheat. It is for this reason that the leaves of eucalyptus are turned towards the sun. Lower trees - acacias - have their own ways: some of their species grow wide feathery leaves in the wet season, change them to long and thin leaves in the dry season, others simply shed their foliage. The Kazarina tree generally does without leaves, their role is played by green shoots. Vines are also found in the eucalyptus forest. One of them, cissus, has become common houseplant... There is a lot of grass in the eucalyptus forest, it is burnt. All vegetation has a grayish tint. It is produced by a waxy coating or covers of the smallest bristles, which impede evaporation. Plant roots, in search of water, grow both in depth and in breadth, and the most powerful roots penetrate far beyond the soil for tens of meters into the rock. Despite the dryness, eucalyptus forests can feed a lot of animals, birds and insects. The most famous animal is the koala, a marsupial bear that lives in the branches of the eucalyptus and feeds on its foliage. Outwardly, the koala resembles a teddy bear. Australian rainforests and woodlands are very sensitive to interference with their lives.
Dry tropical forests in South America are much lower - there are no tall trees like eucalyptus, but there are many types of cacti. But these forests are also light, especially in the dry season, when some of the trees shed their foliage.
Deserts in the tropics are formed where water is sorely lacking even for those plants and animals that can literally get by with drops. Living beings on Earth have a limit of endurance, after which it is no longer possible to adapt. Therefore, the vegetation here is scarce, sometimes it is absent at all. The most terrible deserts are clay and rocky. They are lifeless, their landscapes are almost unchanged throughout the year. The stones cannot withstand sudden changes in temperature and burst, crumbling and falling asleep at the foot of the rocks sticking out like broken teeth. Sandy deserts cover, like waves, moving hills - dunes. The wind-blown sand rolls, flies and is poured from place to place, burying roads and rare oases. However, sand has one very important property: by passing water through itself, it retains it at a certain depth. If water appears, then life becomes possible. In some places, rare bushes of thorns cling to the slopes of the dunes. When there are a lot of them, they stop rolling the sand.
Klima t: In the tropics, the sun stands directly overhead in the sky at least twice a year. And on other days it rises higher than in more northern latitudes. Therefore, the sun in the tropics bakes very strongly and hot air rises up. As a result, an area with reduced air pressure is formed above the equator, and in order to equalize the pressure, constant winds, called trade winds, blow from the northwest and southwest from higher latitudes. They carry air, which contains a lot of moisture. When the air rises, its temperature drops. As the air cools, its water vapor condenses into droplets and large clouds form. Some of them are carried away by the winds, and they rain down, sometimes far from the place of their origin. Of the remaining on the forests almost every day, closer to noon, heavy downpours fall, in some places so regularly, as if right on schedule.
So along the equator, a belt with a damp warm climate is formed. It is in these conditions that a tropical rain forest can exist. It grows wherever the temperature ranges from 20 to 28 C and there is a lot of precipitation per year - 2000 - 4000, and in some places even 10000 mm per year per 1 square meter (for comparison: in the Moscow region - 700 mm). It is also important when these showers pour: precipitation should be distributed evenly throughout the year. So, where tropical forests grow, there are no sharp warming or cold snaps, so the seasons here do not change.
Age: These forests have existed on Earth for 60 million years, although they did not always grow where they are now. After the Ice Age, a green belt formed along the equator. In recent centuries, the area of rainforest has been decreasing more and more rapidly. This happens not because the climate is changing, but solely because of the destructive activities of people. Now on Earth there are 4 to 8 million square kilometers of rainforest.
There are over 40 types of rainforest. I will talk about the three most important:
1. Plain tropical rainforest or evergreen tropical rainforest is the most characteristic of all tropical rainforests. The air temperature here fluctuates from 25 to 27 C, at least 1800 mm of precipitation falls per year, most often in the form of heavy showers that occur in the afternoon. Air humidity is constantly high - 80%. These forests occupy the largest area. Distinguish between virgin, or indigenous, and secondary (grown after the destruction of the virgin) rainforests.
2. Mountain rainforest grows in the tropics at an altitude of 1800 to 3500 m. The air here is also always humid, and very often dense fogs lie. It is always warm during the day, but at night the temperature drops, sometimes even to zero.
3. Alternating humid or summer green rainforests are located in the Northern and Southern hemispheres further from the equator than tropical rainforests, in places where the seasons already differ. There is a short winter every year and some trees shed some of their foliage. Evergreens in such forests include only undergrowth shrubs and herbaceous plants.
A variety of animals live in the wilds of the rainforest. From gigantic elephants, rhinos, hippos to barely visible insects, everyone finds shelter and food here.
Representatives of some groups of fauna in tropical forests are numerous. It is here that most monkeys live, including great apes. Of the birds alone
There are more than 150 species of parrots in South America. The Amazon parrot is easy to teach to speak. The parrot does not understand the meaning of the spoken words - it simply imitates the combination of sounds. There are a lot of insects in the rainforest: over 700 species of butterflies are known in Brazil, which is almost five times more than in Europe. Some of them are giants, such as the tizaniya butterfly: its wingspan is up to 30 cm.
