Africa is the hottest continent on Earth, to which it owes its geographical location. The continent is located in four climatic zones: equatorial, subequatorial, tropical and subtropical. Africa is located between 37 ° north and 34 ° south latitude - that is, in the equatorial and tropical latitudes.

The equatorial belt of Africa is located on the coast of the Gulf of Guinea and stretches deep into the mainland to Lake Victoria. The equatorial climate dominates here all year round. air mass, therefore, there are no seasons of the year, it is constantly hot here, and very often they go heavy rains. Due to abundant moisture (2-3 mm per year) and a very warm climate (above + 20 ° - + 30 ° С throughout the year), a natural area humid equatorial forests. The forests of Africa contain an unimaginable number of animal and plant species, many of which are still unknown to science. The inner regions of the equatorial belt are still uninhabited.

Moist evergreen equatorial forests occupy the Congo basin and the coast of the Gulf of Guinea north of the equator. These forests are distinguished by a huge species diversity (more than 1000 plant species), height (up to 50 m) and multi-tiered (crowns of trees fill almost the entire space).

The first upper tier is made up of giants of woody vegetation, raising their crowns to a height of 40 - 50 m or more. Below are the crowns of trees of the second tier, then the third and so on up to the fourth, fifth and even sixth tiers. With such a multi-layered structure, very little light enters the soil, however, there are also spore plants that are not demanding on light: ferns, selaginella, club mosses.

The following calculations speak of the population density of the African hyla with trees: there are from 400 to 700 large trees per hectare, usually belonging to about 100 different species. These figures show how closely trees grow in a hylaea and how diverse the species composition of such a forest is. There are about 3,000 species of woody plants in the African Hylaea, of which about a thousand are trees of the upper tier, having a height of at least 30 m.

The green ocean of hylais looks especially powerful when viewed from any elevated position. A boundless green ocean really spreads before your eyes, on the surface of which waves roll. Different types of plants that make up the upper tier differ from each other in height, crown shape, and foliage color. All this creates the impression of a green waving ocean.

And inside the forest, greenery is spilled everywhere. Even the bark of trees - and that in humid forests is often green. And if it does not have a green color, then epiphytes located on the trunks and branches of trees make it green. Here, the variously colored flowers and fruits are not striking. There is nothing reminiscent of the diversity of our flowering meadows. It is possible that in the midst of the rains, when we were in the African Hylaea, there were few flowering plants, but we really were in the element of greenery. It is especially good when the peeping sun enlivens the most diverse shades of foliage still wet from the rain.

Animals are also distributed in tiers. Hordes of microfauna, a variety of invertebrates, as well as shrews, lizards and snakes swarm in loose soil and forest litter. The ground layer is inhabited by small ungulates, forest pigs, forest elephants, and gorillas. The crowns of trees were chosen not only by birds, but also by monkeys, colobuses, chimpanzees and even rodents and insects, often reaching very large sizes. There, on large branches, a leopard rests and lies in wait for prey. Ants, termites and amphibians are common in almost all tiers, near water bodies - pygmy hippos, okapi (relatives of giraffes). Here, geochemical processes are actively taking place with the participation of microorganisms and soil fauna, accompanied by the formation of iron and aluminum oxides. Rocks acquire a special structure and color, the so-called weathering crusts are formed, on which red-yellow ferralitic soils (ferrum - iron, aluminum - aluminum) are formed. Many of the plants of the equatorial forests are used in the economy and introduced into cultivation: banana, coffee tree, oil palm, etc.

From the south and north, the zone of humid equatorial forests is bordered by zone of variable-humid deciduous forests, and further - a zone of light forests and savannahs, which is associated with the appearance of a dry period, which lengthens as you move away from the equator.

Vegetation of the equatorial belt

A sufficient amount of heat and moisture causes the development of lush vegetation. The African humid equatorial forest impresses with its richness of species and density of plants. There are about 3 thousand species of trees alone there. In the struggle for light, they grow in 4-5 tiers. The upper tier is formed by high ficuses and palms reaching 70 m. In giant trees, the leaves are hard and dense, often with a shiny surface. So they are protected from the scorching rays of the sun and the impact of rain jets during showers.

The leaves are large and small, narrow and wide, light and bottle-shaped and closes all the cracks and gaps in the dome of the forest. It does not fall all at once, but in turn, leaf by leaf. Therefore, the forest is always green. Plants in it grow, bloom, bear fruit simultaneously and throughout the year. Sunlight barely breaks through the dense crown of trees, so twilight reigns in the forest even in the middle of the day. The forest thicket is shrouded in thick fog. Damp air makes it difficult to breathe. A person in the equatorial forest feels as if at the bottom of a green sea.

Animal world equatorial belt

Animals in the equatorial forest live mainly on trees. In addition to birds, rodents and insects, various monkeys find food and shelter there: monkeys, baboons, chimpanzees. In remote areas inhabited by anthropoid gorillas. Monkeys feed on the fruits of trees, young leaves and arrange nests from broken branches in the tops. Lianas help them move, some of their species are called “monkey ladders”. The largest predator of the forest - Leopard, lying in wait for prey, also hides in the crowns of trees.

The terrestrial inhabitants of the equatorial forest are smaller than in open spaces, since it is difficult for large animals to move in dense thickets. There is almost no grass in the undergrowth, so there are no animals that feed on it. But there are many that eat the leaves of trees and shrubs: the African Fawn, pigs kititsevuhi, okapi - a relative of the giraffe. Crocodiles live in the rivers, and on their banks - pygmy hippos, which are one of the rarest animals on Earth.

All tiers of the forest are inhabited by a variety of birds. There are many parrots among them. The hornbill has a large and thick beak for picking fruit.

Snakes, most of which are venomous, also live in trees. Green color body makes them look like creepers and allows you to skillfully disguise yourself among the leaves. One of the most dangerous snakes in the world consider tree cobra - mamba. She is aggressive and very venomous. Her strong poison strikes nervous system and after a few minutes the person loses consciousness and dies.

A variety of insects are common in all tiers of the forest. Many large bright butterflies. The heaviest insect on the planet, the goliath beetle, lives in the equatorial forests. It weighs 100 g, but despite this, it can fly. Some species of ants move in long columns, eating all living things in their path. The tsetse fly is very dangerous, which carries the pathogen, causes the death of domestic animals and sleeping sickness in humans.

Moist equatorial forests give way to variable-humid subequatorial forests, where deciduous trees grow next to evergreen trees, which shed their leaves in the dry season.

Significance of the equatorial forests

Equatorial forests have a large economic importance. They grow trees that have valuable (strong and beautiful) wood - black (ebony), red, sandalwood. It is used to make expensive furniture. The coffee tree became the ancestor of cultivated coffee. The oil palm yields edible and technical palm oil. The wine palm is used to make wine. Medicines are made from the leaves, bark and fruits of many plants.

However, in nature, equatorial forests are of planetary importance. Moist forest plants absorb huge amounts of carbon dioxide and release oxygen into the Earth's atmosphere. Therefore, they are called the main source of oxygen, the "lungs of the planet." Unfortunately, forests have been cut down for decades for fields and plantations, for timber harvesting. Following the felled trees, animals also disappear.

Presentation on the topic: Africa. Moist evergreen forests of Equatorial Africa.

1 of 6

Presentation on the topic: Africa. Moist evergreen forests of Equatorial Africa.

slide number 1

Description of the slide:

slide number 2

Description of the slide:

slide number 3

Description of the slide:

Moist evergreen forests of Equatorial Africa. Gilea. In the equatorial climate zone, constantly moist evergreen forests (or Hylaia, which means forest in Greek) cover about 8% of the mainland. They are common in the Congo River basin to the north - up to 4 ° N. sh. and south of the equator - up to 5 ° S. sh. In addition, these forests occupy the coast of the Atlantic Ocean up to about 8 ° N. sh. And in river deltas and on coasts flooded at high tide, especially on the shores of the Gulf of Guinea, mangroves dominate. Primary rainforests are preserved only in the central basin of the Congo River. Elsewhere, especially north of the Gulf of Guinea, they have been replaced by stunted secondary thickets.

slide number 4

slide number 5

Description of the slide:

Fauna The humid equatorial forests of Africa have a peculiar fauna, but less rich than the fauna of the open spaces of this continent. In the equatorial African forest, there are few herbivores, and therefore few predators. Of the ungulates, you can meet forest antelopes, very cautious and shy, related to the giraffe, animals - okapi. There are also wild boars, buffaloes, hippos. Of the predatory animals, there are wild cats, leopards, jackals and viverras. Of the rodents, brush-tailed porcupines and spike-tailed flying squirrels are common. There are many monkeys here - monkeys, baboons, mandrills, most of which lead an arboreal lifestyle. Two genera of great apes live in these places - chimpanzees and gorillas. Lemurs are also found here. Wet birds rainforest Africa - these are several types of parrots, banana-eaters, beautifully feathered and brightly colored forest hoopoes, tiny sunbirds, African peacocks. There are many lizards and snakes, a blunt-nosed crocodile is found in the rivers. Of the amphibians, there are especially many diverse frogs. From large predators you can meet tigers, lions, puma, jaguar, panther. The jungle abounds in various reptiles, among which there are many poisonous snakes. Big variety insects and arachnids, including poisonous ones.

Plants in southern Africa have been the most extensively studied. Less well known is the flora of the central and northern parts continent.

The desert biome is the driest biome in Africa and is considered one of the driest places on earth. The largest desert region is the Sahara, in northern Africa. It is located from west coast Africa to the Arabian Peninsula and is part of the world's largest desert system, which extends to the south of Central Asia.

The smaller desert region in southern Africa includes the Namib Desert, located along the western half of southern Africa, especially near the coast, and the Kalahari Desert, which is located mainly inland and east of the Namib Desert.

Where there is more moisture, pastures predominate, and with an increase in the amount of rain, grasslands gradually turn into tropical savannahs. The difference between grasslands and savannahs is subjective but partly determined by tree growth, with more trees characterizing savannah. Grassland/tropical savannah biome forms a wide swath over a larger area central Africa and dominates the eastern and southern parts mainland.

Rainforests cover a much smaller part of Africa than the other two biomes. They are most common in parts of central Africa where there is no dominant grassland/tropical savannah biome and are found close to the coast of central Africa. West Africa. Scattered areas of tropical forests are also found along the main river systems West Africa, from the equator almost to the southern part of the continent.

Tropical deserts of Africa

The Sahara and Namib deserts are dominated by sand dunes or rocky deposits, but most deserts have a noticeable amount of vegetation cover.

The Sahara is characterized by widespread plant species that occur in similar habitats. The deserts of southern Africa have a more distinctive flora, and many species are endemic to specific local areas.

Mesembryanthemum

Plants use several adaptations to survive in harsh desert climates. Mesembryanthemum - a genus of flowering plants, widespread in all African deserts. These plants usually have thick, succulent leaves.

Such succulents store water in their leaves or stems. Most plants open their stomata (small openings in their leaves) during the day to take in carbon dioxide from the surrounding air.

This will lead to big losses water in a desert environment, so succulents open their stomata at night. Through a biochemical process, they store carbon dioxide until the next day when it is released inside the plant, so can occur without the stomata opening.

Hedgehog jointed

To prevent water loss, many succulents have no leaves at all. Jointed barnacle ( Anabasis articulata), found in the Sahara Desert, is a naked succulent with articulated stems.

spurge-thorn

Euphorbia-thorn ( Euphorbia echinus) is another Saharan plant that has succulent, ridge-like stems with thorns. This evergreen shrub reaches 1 m in height. Its stems are branched and covered with short white spikes.

Water dependent desert plants

Water dependent plants are limited to areas near a permanent source of water such as a river, lake, stream.

Date palm

Date palm trees usually reach a height of 21-23 meters. Leaves 4-6 meters long, with thorns on the petiole. The fruit of this tree is the date.

Where water is available, tamarinds and acacias are often found. A variety of different sedges and rushes are found wherever there are abundant permanents, the most famous of which is reeds.

Desert ephemera

Annual plants whose seeds germinate when moisture becomes available and mature quickly, leave seeds and die, are called ephemeral. These plants make up a significant part of the African desert flora.

Most ephemeral plants are herbs. Ephemera are entirely dependent on seasonal or sporadic rainfall. A few days after significant rainfall, the desert turns bright green, and a few more days later, flowers appear, often in abundance.

cushion plant

Some ephemera germinate at astonishing rates, such as cushion plants, which germinate and produce actively photosynthetic seed leaves 10 hours after wetting.

Savannah

Are situated in . They are covered with grassy vegetation, but trees and shrubs grow chaotically. The most common type of savanna in Africa is the savanna-woodland, which consists of tall, moisture-loving grasses and tall, deciduous or semi-deciduous trees that are unevenly distributed.

Savanna grass

Grasses represent the majority of vegetation under and between trees. In some types of savanna, grass can be taller than 1.8 m. Despite much debate, two factors seem to perpetuate the dominance of grasses: seasonal moisture with long intervening dry periods, and occasional fires.

Given the excess moisture and lack of fire, savannahs seem to inevitably become forests. Human activities such as grazing or cutting down trees contribute to the dominance of grasses.

Different varieties of grasses exist in the savannah, but it is difficult to distinguish between them, except during flowering periods. Many grow best immediately after a fire, when exposed to the sun and potential pollinators.

Savannah trees and shrubs

African savannah trees often have relatively wide branches that end at about the same height, giving the trees a distinctive look. Many of them belong to the legume family, namely brachystegia, julbernardia and isoberlinia.

There is a particularly large number of species of acacia, from shrubs to trees, many of which have thorns. Some also have a symbiotic relationship with ants that protect them from herbivores.

Baobab

Baobab is known for its large size, unusual appearance and is found in many regions of the savannah. The tree has an extremely thick trunk with smooth, gray bark. Baobab can live for two thousand years.

Moist Evergreen Tropical Forests

The main characteristics of African moist evergreen tropical forests are their extremely lush growth, high species diversity and complex structure. The diversity is often so great that one tree species cannot be identified as dominant within an area.

Relatively large trees such as ironwood, iroko, and sapele predominate. forest trees grow so closely that their crowns overlap each other, forming a canopy that limits the amount of light that falls under them. Several big trees, called emergent trees, burst above the thick dome.

A layer of smaller trees grows under the main dome. A few small shrubs and herbs grow near ground level, but most herbaceous plants and other perennials are epiphytes growing on other plants.

Almost every available place, trunks and branches of trees have epiphytes that create a unique one. All this dense plant growth is supported monsoon climate, at which more than 1500 mm of precipitation falls annually, most of them occur in the summer.

creepers

Creepers are large, woody vines that cling to trees, many of which hang to the ground. They were made famous in the Tarzan movies. The fruits are eaten by birds or monkeys, and the seeds are deposited in their faeces on branches high in the canopy. The seeds germinate and the stem goes down to the ground. As soon as the stem reaches the ground, it forms the root system; additional stems then develop and grow upward along the trunk of the tree.

Strangler ficuses

After many years, the strangler ficus can wrap itself around the tree so thoroughly that it will not allow water and nutrients to get to its "victim". Eventually, the host tree dies and rots, leaving a hollow trunk.

Epiphytes

Epiphytes are plants that grow or are permanently attached to other plants - phorophytes.

Mosses, or Bryophytes

The most common epiphytes are bryophytes - lower plants associated with mosses and lichens, a symbiotic combination of algae (or cyanobacteria) and fungus.

ferns

The most numerous higher plants are ferns and orchids. As these plants colonize tree branches, they gradually trap dust and decaying materials, eventually resulting in a thin layer of soil that other plants can use.

Grasses are almost entirely absent from the forest floor of the African rainforest; those that grow there have much broader leaves than usual. Some forest floor grasses are capable of growing in deep canopy shade, sometimes so adapted to low light that they can be damaged when exposed to direct sunlight.

Some of the popular houseplants are descended from them so they don't need intense sunlight to survive. However, most of the plants grow under the gaps in the canopy, where more light penetrates.

Africa is considered as a whole, but with some deviations from the point of view of geographical forest areas. In the north of the continent, the regions of the Atlas Mountains form large areas of the South European botanical zone. Forests cover only about 10% of the African continent. Tropical hardwoods predominate, accounting for about 96% of the forests. hardwood temperate climates account for 3%, conifers only about 1%.

North Africa

Forest vegetation has almost disappeared from the territory of Algeria and Tunisia. Small areas of forest land exist in Morocco, where the trees are related to the woody vegetation of Spain and Portugal.

West and East Africa

Tropical forests occupy vast areas of the coastal strip of West Africa from Guinea to Gabon and the Congo Basin. Significant forest areas are located east of the Great Rift Valley in Uganda, Kenya and Tanzania, as well as in southwestern Angola and southeastern Mozambique. There are two types of forests found in these parts of Africa. Mature, or tall, plantations are typical of tropical or rainforests with an annual precipitation over 1500 mm and without a long dry period. The greatest amount of precipitation - about 4,000 mm per year - falls in the coastal western regions. Sparse park-type forests grow in areas with an annual rainfall of 750 to 1,000 mm. Vast areas of these dry savannah forests are located predominantly in East Africa, especially Angola and Zimbabwe. Similar edge forests are found in West and Central Africa.

Economic management of forests owned by regional or local authorities, is strictly controlled. For example, in Nigeria there are about 2 million hectares of tall forest plantations, usually exploited or transferred to timber concessionaires, who are granted the exclusive right to logging. There is also a large area - approximately 6 million hectares - of wooded savannahs with commercial quality plantations suitable for use, but sparse. In addition to the forest resources mentioned, there are large areas of forest without such strict control, which account for about 50% of the total timber harvest in Nigeria.

Republic of South Africa

South Africa is poor in natural forests capable of producing benign business trees. The reason is that over 73% of the territory of the Republic is characterized by low annual precipitation (less than 635 mm) and high summer temperatures. Except for the sparse stands of cedar in some highlands and the wooded savannas in the provinces of Transvaal and Natal, which are not classified as true forests, it can be said that timber forests form a discontinuous band in an area with high rainfall that extends to the east and north east of Table Mountain to the northeastern part of the Transvaal. Large forest areas in South Africa are concentrated only in the George-Knysna region, where on a narrow plateau between the ocean coast and steppe zones Duteniqua and Tsitsikamma have over 48 thousand hectares of timber forests. Slow-growing native tree species proved unsuitable for afforestation, so foreign tree species were imported into South Africa for this purpose and artificial forest plantations of the public sector were gradually created.

The main focus was on the cultivation of eucalyptus trees from Australia and various types of pine from the Mediterranean, Mexico and from southern regions USA. Currently, the Republic of South Africa is largely provided with its own wood and products from it. The main industries - mining, horticulture and winemaking - consume large amounts of local wood species for car building, the production of railway sleepers, box containers and the like. Forest products from maturing plantations introduced tree species allowed to expand the range of wood raw materials for the production of consumer goods and construction needs. Exports from the Republic of South Africa are mainly wood for flooring, raw materials for the manufacture of viscose and cellulose, fibreboard and chipboard, plywood and matches. Wood consumption in South Africa For all purposes in 1972 was 5.3 million m 3 , by 2000 the increase in demand was 23 million m 3 .

Zone humid equatorial forests covers the coast of the Gulf of Guinea to the north of the equator and the basin of the Congo River, stretching for 1600 km from north to south and 5000 km from west to east. This natural area is original and unique. There are practically no seasons here: in winter and summer the air temperature is the same and is approximately +24 °C. More than 2000 mm of precipitation falls per year. It rains every day, usually in the afternoon. Water and heat create ideal conditions for the development of all living things, so humid equatorial rainforests grow here - hylaea(from Greek "sicker" - forest). From the plane they resemble the green sea (Fig. 57).

In the zone of humid equatorial forests, rivers are always full-flowing. During floods, they often flood low banks, and water covers vast areas.

In the conditions of the equatorial forest formed red-yellow ferrallitpy soils(from lat. « ferrum"- iron; grays. « lithos"- stone). It is iron compounds that give them their red color. These soils are very poor nutrients, since organic residues under conditions of moisture and heat are quickly decomposed by microorganisms, and nutrients are quickly absorbed by plants. Therefore, deforestation here leads to a real ecological disaster. The soil in bare areas is washed away by rains, and the sun turns the surface of the earth into a dry crust, where nothing can grow.

In the equatorial forests of Africa, there are over 25,000 species of plants, only trees - about 1,000 species. In these forests it is always stuffy, damp and dark. The forest is so dense that it is impossible to see anything not far from you, everything around is obscured by bushes, vines that braid trees, fallen trees giant trees. The equatorial forest has two characteristics: It is evergreen and multi-tiered.

Evergreen the forest is due to the fact that the plants never completely shed their leaves. Warm and humid weather, hovering all year round, allows the leaves to exist on the shoot for 2-3 years. The leaves, of course, are replaced, but in turn.

Layering is the distribution of plants in height, respectively, the need for light, water and nutrition. In forests temperate zone there are 3-4 tiers of plants, in their hylaea - 6-8 (Fig. 58). At the very bottom - the realm of shade-loving mosses and creeping plants. Shrubs and young trees that are undemanding to light rise higher. There are many tree ferns, bananas. The third tier is trees 15-20 m high, which need more light. Among them are many valuable breeds, such as red, ebony, sandalwood, yellow trees. Meet the same bread, nutmeg trees. Reign even higher ficuses and various types palms. The highest are light-loving, up to 60-80 m high, ceiba with spreading crowns. Due to their extraordinary height, they are called "upstart trees". Such tall trees the leaves are very hard and evaporate little water, because it is difficult to raise it to such a height even for the most powerful root system. Wide support roots help keep the trunk upright (Fig. 59).

Rice. 59. Giant Tree Roots

tree branches lower tier are so densely intertwined that because of them the crowns of the trees of the upper tier are not visible. At the very surface of the earth there is complete darkness. Only 1/120 is included sunlight, so there is no grass at all. Instead, they rise from the ground creepers- trees with a flexible and long (up to 300 m) stem, which, wrapping around the trunks, bring their leaves and flowers to the light. Making your way through such a forest without a path is a difficult and dangerous business.

African hylaea is the birthplace of valuable economic tree species: coffee tree, oil palm, cocoa.

Rice. 61. Chimpanzee

The fauna of the humid equatorial forests is rich and diverse. All tiers of the forest are inhabited. Great apes live here - gorillas and chimpanzees. A real giant is a two-meter gorilla (rice. 60) with thick black fur. She is distinguished by great physical strength, spends most of its life on the ground, although from time to time it climbs trees. Chimpanzee (Fig. 61) smaller than a gorilla (up to 1.5 m tall), has a large brain, is distinguished by complex behavior, lives in trees. From other monkeys are known monkeys and baboons.

Numerous birds flutter between the trees: fruit dove, different types parrots, hornbills, woodpeckers, sunbirds (Fig. 62), banana-eaters.material from the site

Rice. 62. Sunflower

Lots of insects termites, mosquitoes, beetles, butterflies, bees, dragonflies, scorpions, spiders.

Many insects are dangerous to human health: malarial mosquitoes spread pathogens of tropical fever, tsetse fly- sleeping sickness.

Of the land animals common lizards, shrews, earth vipers, pythons, racemos and forest pigs, African pygmy deer height 40 see, forest antelope. An amazing creation of nature is okapi. When this animal was first seen, it was mistaken for a zebra because of the striped hind limbs. However, it turned out that this is a pygmy giraffe, which is three times lower than its tall relative. Occasionally found pygmy hippopotamus. It weighs 10-12 times less than an ordinary hippopotamus.

Like a giant chain, humid equatorial forests cover the zone from the north and south variable wet forests. This is a transition zone from humid equatorial forests to grassy savannahs. It has much in common with the flora and fauna of the equatorial forest. But the rhythm of life in these forests depends on the season. Variably humid forests are more developed by man than equatorial ones.

The population living near or in variable-humid forests is small. Local tribes are engaged in hunting and fishing. Nowadays, large areas of forests are cut down for the sake of valuable tree species. Animals die along with the forest.

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

On this page, material on the topics:

• rkbvfn dj dkf;ys] "rdfnjhbfkmys[ ktcf[ fahbrb
• hylaea - geography
• a message about the equatorial forests of africa
• animals of the humid equatorial forests
• forest hylaea africa