Building and structure. Give a generalized description of the structure of a wet rainforest is almost impossible: this is the most difficult plant community detects such a variety of types that they are not able to reflect and the most detailed descriptions. A few decades ago, they believed that the wet forest was always impassable thickets of trees, shrubs, terrestrial herbs, lian and epiphytes, because they were mainly judged by the descriptions of mountain wet forests. Only relatively recently it became known that in some wet rainforests due to the dense closer crowns of high trees, sunlight almost does not reach the soil, so there is a meager thing here, and through such forests can be passed almost freely.
It is especially emphasized species diversity Wet rainforest. It is often noted that there are hardly two copies of the trees of the same species. This is an obvious exaggeration, but at the same time, 50-100 species of trees can be found in 1 hectare.
But there are also relatively poor species, "monotonous" wet forests. These include, for example, special forests, consisting mainly of the trees of the Farmal Family Family (Dipterocarpaceae), growing in very rich in the sediments of Indonesia. Their existence indicates that in these areas the stage of optimal development of wet rainforests has already been passed. The extreme abundance of precipitation makes it difficult for the soil aeration, as a result, there was a selection of plants adapted to habitat in such places. Similar conditions for existence can also be found in some raw areas South America And the Congo pool.
Dominant component of a wet rainforest - trees of different appearance and different height; They constitute about 70% of all species found here. higher Plants. There are three tiers of trees - the top, middle and lower, which, however, are rarely pronounced clearly. The upper tier is represented by separate giant trees; Their height, as a rule, reaches 50-60 m, and crowns are developing above the crowns of trees below the arranged tiers. The crowns of such trees are not closed, in many cases these trees are scattered in the form of individual copies that seek overgrowths. In contrast, the crown of the trees of the middle tier, having a height of 20-30 m, usually form a bounted canopy. Due to the mutual influence of neighboring trees, their crowns are not so wide as the trees of the upper tier. The degree of development of the lower wood tier depends on the illumination. It makes up trees reaching an average of about 10-meter heights. A special section of the book will be dedicated to Lianam and epiphytes in various forest tiers (p. 100-101).
Often there are also yar of shrubs and one two tiers of grassy plants, they make up representatives of species capable of developing with minimal illumination. Since the humidity of the surrounding air is constantly high, the dust of these plants remain open throughout the day and the plants are not threatened with withering. Thus, they constantly assimilate.
According to the intensity and nature of growth, the trees of a wet rainforest can be divided into three groups. The first are species, whose representatives are growing rapidly, but long live; they are first developing where in the forest or natural wayOr as a result of human activity, clarified sections are formed. These light-loving plants stop their growth about 20 years and inferior to other species. Such plants include, for example, South American Balz Tree ( Ochroma Lagopus.) and numerous MIRMECOFUL types of cecropy ( Cecropia.), african species Musanga Cecropioides. and growing in tropical asia representatives of the family family related to the kind Macaranga..
The second group covers species whose representatives in the early stages of development are also growing quickly, but their growth in height continues longer, and at its end they are able to live for a very long time, probably not one century. This is the most characteristic trees Upper tier whose crowns are usually not shaded. These include many economical trees, whose wood is called "Red Tree", such as species related to childbirth Swietenia. (tropical america), Khaya. and Entandrophragma. (Tropical Africa).
Finally, the third group includes representatives of shadowish species growing slow and long-lived. Their wood is usually very heavy and firm, it is difficult to process it, and therefore it does not find so widespreadlike wood trees of the second group. Nevertheless, the third group includes species that give noble wood, in particular Tieghemella Heckelii. or Aucoumea Klainiana.whose wood is used as a red wood substitute.
For most trees are characterized by straight, columns trunks, which often, without branched, rise more than 30 meter height. Only there in separately standing giant trees develops a spreadable crown, while in the lower tiers, as already mentioned, the trees due to their close location form only narrow crowns.
In some species of trees near the bases of the trunks, formidable roots are formed (see Figure), sometimes reaching the height of up to 8 m. They give trees greater stability, as root systems developing shallow, do not provide sufficiently strong fixation of these huge plants. The formation of wild roots is due to genetically. Representatives of some families, for example, by Morasaee (Tutov), \u200b\u200bMimosaceae (Mimosove), Sterculiaceae, Bombacaceae, Meliaceae, Bignoniaceae, Combretaceae, they are quite often, and others, such as Sapindaceae, Apocynaceae, Sapotaceae, are not at all.
Trees with spine roots most often grow on raw soils. It is possible that the development of achesive roots is associated with a bad aeration characteristic of such soils, which impede the secondary growth of wood on the inner sides of the side roots (it is formed only from the external parties). In any case, in trees growing on moisture and well-being aerated soils of mountain rainy rainforests, there are no shell roots.
For the trees of other species, wandering roots are characteristic; They are formed above the base of the trunk as the apparent and especially often occur in the trees of the lower tier, also growing mainly in raw hasshes.
Differences in the microclimate, characteristic of various tiers of wet rainforest, are reflected in the structure of the leaves. While the trees of the upper tiers usually have elliptical or lanceal in the outlines, smooth and dense leather leaves of the Lavi leaves (see Figure on page 112), capable of transferring the alternation of dry and wet time periods during the day, the leaves of the lower tier trees are detected. Signs indicating intensive transpiration and rapid moisture removal from their surface. They are usually larger; Their plates have special pointers, on which water is going to, and then drops with drops, so there is no water film on the surface of the sheet, which would prevent transpiration.
On the shift of foliage in trees of wet rainforests do not affect external factors, in particular, drought or cold, although here you can replace the well-known frequency, varying from different species. In addition, some independence of individual shoots or branches is manifested, so it's not all the tree immediately, but only part of it.
The characteristics of the climate of the wet rainforest affect the development of foliage. Since there is no need to protect the growth points from cold or drought, as in areas with temperate climatesThe kidneys are expressed relatively weakly and are not surrounded by renal scales. In the development of new shoots, many trees of a wet rainforest have a "drooping" of leaves, which is caused by an extremely rapid increase in their surface. Because of mechanical fabrics They are not formed as quickly, young stiffs first, as if sipped, hang down, foliage seems to turn. The formation of a green pigment - chlorophyll - at the same time it can also slow down, and young leaves turn out to be whitish or - which is due to the content of the anthocian pigment - reddish (see Figure at the top).
"Swimming" of young leaves at chocolate tree (Theobroma Cacao)
The following feature of some trees of wet tropical forests - caulifloria, that is, the formation of flowers on the trunks and noble sections of the branches. Since this phenomenon is observed primarily at the trees of the Lower Yarus of the Forest, scientists treat it as an adaptation to essentially found in these habitats to pollinate with the help of bats (chipterophilia): animal pollinators - bats and bats - when you arrive to the tree, it is more convenient to grasp the flowers .
Birds are played with a significant role in the transfer of pollen from a flower on a flower (this phenomenon is called "Ornithofilia"). Ornithophilic plants are noticeable due to the bright color of their flowers (red, orange, yellow), while the chrops of roofil plants are usually unbroken, greenish or brown.
A clear difference between tiers of shrubs and herbs, such as, for example, is characteristic of the forests of our latitudes, there are practically no wet tropical forests. It is only possible to note the upper tier, which, along with high large-scale representatives of families of banana, marrine, ginger and aid, includes shrubs and a young teen trees, as well as the lower tier, represented by low-spirited, extremely shadowish herbs. According to the number of species herbate plants In a wet tropical forest, trees are inferior; But there are also plain wet forests that have not experienced the effects of a person in which only one poor herbs tier is developed.
Attention is drawn to the fact that not yet found an explanation of the fact of spending, as well as the presence of metallic-brilliant or matte-velvet sections of the surface in the leaves of plants living in the grained tier of the grass of a wet tropical forest. Obviously, these phenomena are to some extent associated with the optimal use of that minimum. sunlightwhich comes to such habitats. Many "Peppercut" Wet Tropical Forest Herbal Herb Blood Blood Plants decorative plants, for example, types of labor Zebrina, Tradescantia, Setcreasea, Maranta, Calathea, Coleus, Fittonia, Sanchezia, Begonia, Pilea et al. (Figure on page 101). In deep shadows, various ferns are dominated, Plunuki ( Selaginella) and mosses; The number of their species here is especially great. So, most types of plants (and about 700) are found in wet rainforests.
Saprofitis-living on the soil of wet rainforests are noteworthy (that is, using decomposing organic matter) mushrooms of clanthraceae and phallaceae families. They have peculiar fruit bodies - "fungi-flowers" (see Figure on page 102).
Liana. If you sail through the tropical wet forest along the river, the abundance of Lian (climbing on the trees of plants with decisive stems) is striking - they, exactly a dense curtain, cover trees growing along the banks. Liana is one of the most amazing components of the vegetation cover of tropical areas: over 90% of all their species occurs only in the tropics. Most grows in wet forests, although for their development they require good lighting. That is why they are not everywhere they meet with the same frequency. First of all, they can be seen in the forest edges, on the naturally formed brightened areas of the forest and - at least sometimes - in permeable for sunlight of the tiers wood plants (See Figure on page 106). They are especially abundant on plantations laid in the field of wet tropical forests, and in secondary forests appearing on cutting down. In the plain wet forests that did not experience the effects of a person, where thick, well-developed crowns of trees are tightly closed, the Liana is relatively rare.
By the method of fastening on plants that serve as a support, Liana can be divided into different groups. For example, based on lianas can be held on other plants using support (clinging) shoots or leaves, spikes, spines, or special crochet type. Typical examples of such plants can serve palm rathangs Calamus., 340 species of which are common in the tropics of Asia and America (see Figure on page 103).
Fixed Liana roots are held on the support using a plurality of small apparent roots or covers it longer and thick roots. These are many trendy lianas from the family of aroid, such as types of labor Philodendron, Monstera, Raphidophora, Syngonium, Pothos, Scindapsus, as well as vanilla ( Vanilla.) - Rod from the family of orchid.
Curly Liana covers a support that is largely smaller in the length of interstices. Usually as a result of subsequent thickening and decisions such shoots are fixed tight. The group of curls include most tropical lian, for example, representatives of the families of the Mimosov and related family of the Caesalpiniyev family, in particular entada Lyezhenaya ( Entada Scandens.); The beans of the latter reach 2 m in length (see Figure on page 104). To the same group belongs to the so-called monkey staircase, or Bauginia Sassaparevoid ( Bauhinia smilacina.), forming thick decorating shoots, as well as lianas with bizarre flowers (Kykazone views, Aristolochia; Family of kirkazonovy) (see Figure on page 103).
Finally, the liana's assfill attaching the tolerances form a decisive mustache - they cling to plants that serve as a support. These include representatives of the species common in all tropics Cissus. from the grapes family different types legumes, in particular (see Figure), as well as the types of passion ( Passiflora.; Family password).
Epiphytes. Extremely interesting adaptations to the conditions of existence in wet rainforests have so-called epiphytes - plants living on trees. The number of their species is very large. They abundantly cover the trunks and branches of trees, thanks to which they turn out to be quite well lit. Developing high on the trees, they lose the ability to get moisture from the soil, so water supply becomes vital for them an important factor. It is not surprising that there are especially many types of epiphytes where the preciputes are abundant, and the air is wetaled, but the absolute amount of dropping moisture is crucial, but the number of rainy and foggy days is crucial. The unequal microclimate of the upper and lower wood tiers also causes the fact that the community-dying communities of plants-epiphytes differ very much species composition. In the outer parts of the crowns, light-loving epiphytes dominate, while the shadow-enough dominates inside, in constantly wet habitats. Light-loving epiphytes are well adapted to the change of dry and wet periods of time occurring during the day. As shown by the following examples, for this they use different features (drawing on page 105).
In the orchid presented a huge number Species (and most of the 20,000-25,000 types of orchids are epiphytes), organs, stocking water and nutrients, serve thickened areas of shoots (so-called boules), leaf plates or roots. Such a lifestyle also contributes to the formation of air roots, which are covered with layers of cells quickly absorbing water (Velamen).
Wet rainforest plants, developing in the surrounding tier
The family of bromels, or pineapple (BromeLiaceae), whose representatives are common, with one exception, in North and South America, consists almost only from epiphytes whose rosettes of leaves, similar to funnels, serve waterborne tanks; Of these, water and nutrients dissolved in it can be absorbed by flakes located at the base of the leaves. The roots serve only as organs attaching plants.
Even cacti (for example, types of labor Epiphyllum, Rhipsalis, Hylocereus and Deamia.) In mountain wet rainforests grow as epiphytes. With the exception of a few species of kind RhipsalisAs well as in Africa, Madagascar and Sri Lanka, they all grow only in America.
Some fern, for example, a bird's nest, or anxular nest ( Aspleniumnidus.), and fern-deer horns, or platitizerium Olenegor ( Platycerium.), due to the fact that the first leaves form a funnel-shaped outlet, and the second has special leaves adjacent to the tree trunk, like false pockets (drawing on page 105), are even able to create a soil, constantly wet substrate in which Russe their roots.
Epiphyts developing in shaded habitats are presented primarily by the so-called hygromorphic ferns and mshams that have adapted to existence in a wet atmosphere. The most characteristic components of such communities of epiphylet plants, especially pronounced in mountain wet forests, are hymenophillery, or thin-digit, ferns (Hymenophyllaceae), for example, representatives of childbirth Hymenophyllum and Trichomanes.. As for lichens, they do not play such a large role due to slow growth. Flower plants in these communities meet types of labor Peperomia. and Begonia..
Even leaves, and above all the leaves of trees lower Yarusov Wet rainforest, where the humidity of the air is constantly high, can be populated with different lower plants. This phenomenon is called epiphilia. Set on the leaves predominantly lichens, liver mosses and algae, forming characteristic communities.
A peculiar intermediate stage between epiphyts and lianami is hemepypify. They are either growing first as epiphytes on the branches of trees, and as the air roots applying to the soil, become independently strengthened in the soil by plants, or in the early stages develop as lianas, but then lose touch with soil and thus turn into epiphytes. The first group includes so-called fragrance trees; Their air roots, as if by the network, cover the trunk of a tree-support and, racing, so prevent it from thickening that the tree will eventually die and the totality of air roots becomes after that the system of "trunks" of an independent tree in the early stages of the development of ex-epiphet. The most characteristic examples of fragrance trees can serve in Asia species Ficus. (Family), and in America - representatives of the kind Clusia. (family of hunting). The second group includes the types of family of aroid.
Evergreen wet rainforest lowlands. Although the floristic composition of wet rainforests in different parts of the globe is very different, and the three main areas of such forests detect only a minor similarity in this regard, yet in the nature of their vegetation cover, similar modifications of the main type can be identified everywhere.
The prototype of the wet rainforest is considered an evergreens of a wet rainforest of unlocked lowlands, without a long time with raw. This, so to speak, the normal type of forest, about the structure and the peculiarities of which we have already spoken. Forest communities of river floods and flooded lowers, as well as swamps differ from it usually a less rich species composition and the presence of plants that have adapted to existence in such habitats.
Pointed wet tropical forests They are found in close proximity to rivers on regularly flooded territories. They develop, in habitats formed as a result of annual deposits of rich nutrients of river nansions - brought by the river weighted in water and then crawled smallest particles. This muddy water is so-called "white-breeding" rivers bring mainly from the chamber of their pools *. Optimal nutrient content in the soil and relative security of running water with oxygen determine high productivity plant communitiesdeveloping in such habitats. Pointed tropical forests are difficult to master them by man, so they also mainly retained their primaryness.
* (Rivers, the authors of this book called "white", in Brazil is called white (Rios Blancos), and "draft" - black (Rios Negros). White rivers carry muddy water rich in suspended particles, but the color of the water in them can be not only white, but also gray, yellow, etc. In general, the Amazon Basin River is characterized by an amazing variety of water coloring. Black rivers are usually deep; In them, the water is transparent - they seem dark only because they have no suspended particles reflecting the light. Missing humus substances dissolved in water only enhance this effect and, apparently, affect the shade of color.)
Wet Ratin Forest Lians
Moving from the very shores of the river across the floodplain to its edge, you can identify a characteristic sequence of plant communities, due to the gradual decrease in the level of the soil surface from high routing shafts to the edge of the floodplain. On rarely sleeves, rich-riots rich ribbons are growing on the rich rivers, then the river is passed to the real bounted forest. At the long-distance from the shore, the floodplains are found lakes surrounded by cane or herbal swamps.
Swampy rainforest. In habitats, the soils of which are almost constantly covered with standing or slowly flowing water, crotted tropical rolled rainforests. They can be found primarily about the so-called "draft" rivers, the origins of which are in the disturbed areas. Therefore, their water does not carry suspended particles and are painted from olive to black and brown due to the content of humus substances in them. The most famous "draft" river - Riou Nehru, one of the most important influx of Amazon; It collects water from a huge territory having podzolic soils.
Unlike the floodplain wet rainforest, the swampy forest, as a rule, covers the entire valley of the river. There is no deposition of pumps, but, on the contrary, only a uniform leaching, therefore the surface of the valley of such a river is smooth.
Due to the insecurity of habitats with nutrients, the swampy rain forests are not so lush as floodplain, but due to lack of air in the soil there are often plants with air and wandering roots. For the same reason, the decomposition of organic substances occurs slowly, which contributes to the formation of powerful peat-like layers, most often consisting of more or less decomposed wood.
Highe applens of wet lowlands. For some areas of rainy rainforests, short arid periods are characterized, causing foliage shift in the trees of the top tier of the forest. At the same time, the lower wood tiers remain evergremen. Such a transitional stage to the dry forests losing in the rain period (see page 120) got the name "Handsheette, or semi-estate, wet forests of lowlands." In the arid periods there may be a movement of moisture in the soil from the bottom up, therefore such forests are obtained by sufficient nutrients and turn out to be very productive.
Tropical epiphytes wet forest
From above asplenium nesting asplenium nidus and bottom Cattleya Citrina
Mountain tropical wet forests. The forests described above, the existence of which is determined by the presence of water, one can oppose such variants of a wet rainforest, the formation of which is associated with a decrease in temperature; they are mainly found on wet habitats in different high-rise belts mountain areas tropical regions. In the foothill belt, at a height of about 400-1000 m above sea level, the wet rainforest is almost no different from the lowland forest. It has only two tiers of trees, and the trees of the upper tier are not so high.
But the tropical wet mountain belt forest, or, as they say, a mountain wet forest growing at an altitude of 1000-2500 m, detects more significant differences. It also has two wood tiers, but often it is difficult to identify, and their upper border often does not exceed 20 m. In addition, there are fewer types of trees than in wet lowlands, there are no and some characteristics Trees of forests, in particular, and wobble roots, as well as Caulifloria. Tree leaves are usually smaller and do not have sharpening to remove water droplets.
In tiers of shrubs and herbs, ferns and bamboo species are often dominated. Epiphyts are very abundant, while large lianas are rare.
At even larger heights of constantly wet tropics (2500-4000 m), mining wet forests are replaced by subalpiy mountain forests developing at the cloud level (see t. 2).
Wet tropical forests were formed in a belt between 10 0 North and 10 0 southern latitude, but with favorable climatic conditions, it spreads to 20 0 southern and northern latitudes.
The main areas of distribution on the land of wet rainforests - to the eastern slopes of the Andes in South America, including the Malacca Peninsula, the Zonda Islands, the Philippine Islands to New Guinea inclusive and West Africa - the coast of the Guinea Bay and the Congo River Pool. In addition to these major arrays of wet rainforests, the Elephants of the Andes, Central America and Islands are distributed Caribbean, on the slopes high volcanoes East Africa (Kilimanjaro et al.), Sri Lanka and in Northeast India (on the Indian Peninsula, they are destroyed for most of their range), in Indochita (areas have been preserved, reaching in the north of China's southern provinces) on many of the Pacific Islands.
Compared to more northern (southern) regions, climatic conditions Wet tropical forests change little over the year. The proximity to the equator means that the amount of light and the length of the day remain almost the same all 12 months. The only oscillation, in the rain, is quite relative - from abundant to the abundant. And it continued so much long that all other habitats, with the exception of the World Ocean, seem to be asked and transient. The lakes are styled and become swamps over a few decades, green plains turn into the desert in the century, even the mountains are hosted by glaciers for the millennia. But the hot wet jungle covers the land along the equator tens of millions of years. Perhaps this stability itself served as one of the reasons for the truly incredible diversity of life, which we are watching there now.
Wet tropical forests where richer decades; The crowns of trees growing here are closed much higher, and the number of dwelling species is twice as much. Currently, the world of wet rainforests is a huge biomass, the richest and diverse biome, significantly superior abundant game african savannah and coral reefs, swamps and thick clusters of floating seaweed.
Wet tropical forests occupying no more than 1/3 of the total wood painted area of \u200b\u200bthe planet include 4/5 of the entire vegetation on Earth. At 1 hectare, up to 1000 tons of vegetable material. This is the most ancient and rich in species of the plant formation of the Earth.
Our environment is sometimes perceived as something of granted. Even something unique as is forgotten. It seems a little knowledge, and the push in the right direction can cause people to appreciate the environment. So why not start with a miracle, which is the rainforest?
Despite the fact that rainforests cover less than two percent of the entire surface area of \u200b\u200bthe Earth, about 50% live in them. They are also found on all continents, with the exception of Antarctica. It is very amazing! Now let's see what plants are found here. From 40,000 species, in this article you will learn about 10 most amazing plants The rainforest, which will make up your mind and help get acquainted closer with the amazing nature of our planet.
Bananas
Bananas are one of the amazing rainforest plants. Despite the fact that they are like trees, bananas are not trees, but gigantic herbaceous plants. A year later, they reach full heights ranging from 3 to 6 m. Flowers ultimately develop into fruit, and then ripen and used in food by man and animals. Banana stems can weigh almost 45 kg and almost 93% consist of water.
Spread: Central America, South America, Africa, Southeast Asia, as well as not tropical regions, such as the United States of America, thanks to modern agricultural technologies.
Orchid
Orchids are the largest plant of plants in the world. Types are widely different in weight and size, some petals reach 75 cm long, and inflorescences grow up to 3 m in length. They can also have a different color, with the exception of black. Orchids are growing on the rocks, in the soil, underground and on other plants, relying on certain insects or birds to pollinate.
Spread: Extremely well adapted and grow in Central America, South America and along the Andean Mountains.
Coffee
What would you do if you had no cup of coffee in the morning? Surely, it would be terrible. For coffee you can thank the coffee plant of the rainforest. It is capable of growing up to 9 m in height, but is considered a bush or shrub. Coffee fruits resemble grapes, and contain two coffee beans inside. In order for the plant to grow, it takes six to eight years, and the duration of his life can reach 100 years.
Spread:In Ethiopia, Sudan, as well as Latin America grows more than two thirds of the total coffee trees on the planet.
Brazilian nut
Towing above all other trees in the rainforest, Brazilian walnut can reach more than 50 m in height. The plant is widely known with its fruits rich in nutrients. The outer layer of the fetus is so hard that only Aguti - large rodent from sharp teethmay damage him.
Spread: Tropical forests of Brazil, Colombia, Venezuela, Ecuador and Peru.
Justice beautiful
This beautiful plant is found in tropical forests in the form of a bush or tree. It would be possible to think that the red part of the plant is flowers, but in fact it is a bract. Flowers are small yellow inflorescences in the middle of the leaves. In addition, to clarify rumors, they are not poisonous, although some believe that it is.
Spread: Mexico and Central America.
Cocoa
Cocoa tree is an evergreen plant, the fruits of which are pods containing from 20 to 60 reddish-brown cocoa beans. To obtain 500 g cocoa, it takes from 7 to 14 pods. It is very important that Cocao was going correctly.
Spread: It grows below the height of 300 m above sea level in the regions that get about 10 cm of precipitation per month. Cocoa arose in the rainforest of the Amazon River Basin and today can be found in South Mexico.
Gevei Brazilian
This tree can grow up to 40 m in height. Geveya Brazilian is characterized by milky white juice, which is commonly called natural rubber, and produce rubber from it. The tree is used to produce rubber at the age of six.
Spread: Brazil, Venezuela, Ecuador, Colombia, Peru and Bolivia.
Heliconia
This genus of plants includes nearly 200 species common in tropical america. Depending on the species, these plants are capable of growing up to 4.5 m in height. Flowers can be painted in shades of red, orange, yellow and green. Bracts actually hide the flowers of the plant and protect nectar, so only certain birds can get to them, such as Hummingbirds. Butterflies also love to enjoy sweet nectar.
Spread: Central and South America.
Sapodilla
This strong wind-resistant tree has an extensive root system and a bark containing milky Juice, called latex. Egg-shaped fruits contain a grainy yellow fruit inside, and in taste look like a pear. It is considered the best fruit in Central America, and even mammals of the rainforest love to eat them. The first chewing gum was created from the fruits of Sapodillas by Aztecs!
Spread: South Mexico, Belize and Northeast Guatemala.
Bromelle
Bromellene includes more than 2,700 species that grow on Earth, on the rocks and on other plants. These beautiful plants have bright flowers. One of the most famous representatives Bromeliev family - sweet, wonderful pineapple fruit! Bromelia even sometimes are a shelter for frogs, snails and salamander, where they remain for life.
Spread: Central and South America. One species is also found in West Africa.
Tropical forest is a house for many amazing plants, including those with many of us; Therefore, it is very important to keep this unique. Imagine that you live without bananas, coffee, chocolate, pineapples and beautiful orchids. This is quite sad!
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A wide strip of wet forests spread at the equator. It passes through the territory of Central and South America, Central Africa, South-East Asia and Northern Australia. These forests are the most complex ecosystem on Earth, which has the most diverse and rich resources. However, despite their entire importance, tropical forests are destroyed and disappear with threatening speed. Wet forests grow in areas where it is constantly high, and the precipitation falls a lot. For millions of years, wet forests have become the most populated on our habitat planet. They account for less than 10% of the land area, but there lives from 50 to 70% of all earth species Plants and animals. The biggest wet forests grow in Amazonia (Brazil). We will tell about these pages about them. Local Indians hunt by special wind tubes. The number of Indians in Brazil over the past 400 years has decreased from 5 million to 200 thousand people. Many of these huge trees are allowed additional shoots for support, as their own roots are empty inside and weak. Soil in the forests is covered with a layer of fallen leaves with a thickness of several centimeters. In this layer, necrophages are actively recycled organic substances, and the roots of the plants quickly absorb minerals. This process is so active that very few mineral substances remain in the lower layer: their main mass is in all sorts of vegetation species. When clearing the forests and their burning, the minerals contained in plants turn into ashes. The root system is destroyed, and the surface layer of the soil is washed off strong rains. It becomes lowland, and the area where the lives have recently boil, turn into. To restore the forests on such lands, many centuries will be required.
Tiers
All wet forests have a similar structure with five major tiers. In each tier, its own vegetable and animal life. Often, tiers merge. Sometimes one of the tiers (or more) is absent. Top tier is the most tall trees, rising 10-15 m above the bulk of vegetation. Hence the American Eagles Garpia and other predators track their prey. The second tier (canopy) is a strip of a width of about 10 m. At an altitude of 30-40 m. It is a solid green roof of intertwing branches and leaves of wood vertices. Most plants and animals are justified here attracted by abundant sunlight. Teen - consists of tops of small trees that get less light, such as palm trees, and young trees seeking to. It is much crushed than the second tier, and here lives its community of plants and animals. The undergrowths are shrubs and small trees that get scattered sunbeams, breaking through the branches and crowns of the upper tiers. Where the sun almost passes, shrubs and herbs grow very poorly. When through the lumens of the second tier penetrates more than the sun, shrubs and herbs grow faster. Located vegetation - these are ferns and herbs. Single types of mammals live here, such as Tapir, and many insects.
Model of wet rainforest
If you have a large aquarium, you can create a miniature model of a wet forest. At the bottom of the aquarium, pour a layer of gravel and charcoal, and on top of it there are several centimeters of fertile compost. Fuss slightly so that gravel pebbles appear in it. Rail various exotic plants. Cover the glass lid and put it in a warm place, but not in the sun. Plants will begin to grow rapidly. It will be wet, and it will be constantly circulating between the compost, plants, air and aquarium. Every few months add some water every few months. Square exotic plants. They can be bought in the store. Small flowering plants, such as orchids, make colorful variety. Plant plant at some distance from each other: they need space.
Forest people
Wet forests - native scrap for many natives living in harmony with the outside world. Their life experience in the forest is very valuable for us if we want to learn to use forest resources wisely. However, in our days, the natives constantly expel and displace their will contrary to their will and fundamental human rights. Wild tribes are dying with the death of forests, carrying out their invaluable experience.
The value of wet forests
Wet rainforests play a vital role in climate regulation on our planet: they occupy a special position in the cycles of the oxygen, carbon and water cycle. In addition, tropical forests are the most valuable source of raw materials for medicine and one of the main sources of new types of food (about 1650 species of plants growing in them). People have already begun to actively use huge resources of wet forests. However, it is necessary to do it more thoughtfully: it is necessary to find a balance (equilibrium) between the large-scale use of forest resources - such as wood, rubber and nuts - and the preservation of the forests themselves.
On our planet, more than 50% of wet forests have already been destroyed, and their destruction continues. As a result, in countries where these forests grow, the population is fast, and the liberated land is distributed unequal (see Article ""). The reason for mass cutting of forests is the constant demand for wood in developed countries and ineffective forest recovery programs. It is necessary to significantly change the approach to solving all these problems.
A tropical forest - Forest distributed in tropical, equatorial and subscance belts between 25 ° C. sh. and 30 ° sh. Rainforests There are in a wide belt surrounding the Earth on the equator and taking only ocean and mountains.
Total atmosphere circulation comes from the high zone atmospheric pressure in the area of \u200b\u200bthe tropics in the zone low pressure In the area of \u200b\u200bthe Equator, the evaporated moisture is transferred in the same direction. This leads to the existence of a wet equatorial belt and dry tropical. Between them is a subequatorial belt, in which moisturizing depends on the direction of the wind (monsoon), depending on the time of year.
The vegetation of tropical forests is very diverse, depends mainly on the number of precipitation and their distribution at the time of the year. In the case of abundant (more than 2000 mm) and their more or less uniform distribution are developing wedgeotropic evergreen forests. As they remove from the equator, forests appear in which moisturizing depends on the time of year: the rainy period is replaced by dry. This is winter-depleted variable-wet rainforests with falling drought leaves. Next, these forests are replaced by savanna forests. At the same time in Africa and South America, monsoon and equatorial forests Replaced by savanna forests from west to east. With an even more dry climate, the treasures are cutting, savanna forests are replaced by xerofilic column forests and thickets of shrubs.
Distribution of tropical forests
Immediately it will become clear where the rainforests grow, if you explain that they seek the planet by the Equator. They are located in a wet equatorial, dry tropical, moderate subequatorial belts, representing a clear line, interrupted only by mountains and oceans. Depending on the air temperature and the amount of precipitation, vegetation changes. Rainy areas are covered with evergreen flora, more dry regions are typical leaf fall plantsAnd then there are savanna forests. Both in South America and in Africa in the West are monsoon, in the east - savannah, and in the middle - equatorial forests.
Forest levels
The description of the tropical forest will be more understandable if it is divided into tiers. You can select four main levels. The topmost is evergreen trees up to 70 m high, they are mostly green caps only on top, but from below - naked trunks. These giants withstand hurricanes without problems, temperature drops, covering the remaining tiers from bad weather. The main hosts here are eagles, butterflies, bats. Then there is a forest canopy consisting of 45-meter trees. The crown level is considered the most diverse, approximately 25% of all types of insects live here. Scientists agree that 40% of the species of all plants on the planet are located on this tier, although it is not fully studied.
Classification of tropical forests
The main groups of rainforest formations are rain, or wet, and seasonal.
- Wet tropical forests - distributed in equatorial belt, are characterized by abundant precipitation (2000-7000 mm, sometimes even up to 12,000 mm) and relatively uniform distribution during the year with almost unchanged average temperature air (24-28 ° C). Major distribution regions: South America, Central Africa, Southeast Asia and Australia. Wet tropical forests are considered the center of evolutionary activity, a place for the formation of new species that extend to the rest of the regions. They are the most ancient type of vegetation, have practically not changed from the tertiary period. The main groups of humidotropic forests are wet evergreen mountain forests, tropical swampy forests, rain tropical plain forests, mangra.
- Mangrass are common in the tidal and tidy zone of tropical coasts and, if warm currents are favorable, then along the shores in moderate climatic zone. They grow in places free from water during low tide and flooded during the tide.
- Tropical mountain evergreen forests grow as a rule above 1500-1800 m, where air temperatures are lowered to 10-12 ° and lower, which does not give to develop many organisms. Relative preservation of these forests having a noticeable value in stabilization natural conditions (water protection, anti-erosion, etc.), contributes to their low economic significanceassociated with the difficulties of mastering the terms of the relief.
- Swampy forests occupy a noticeable smaller area than uneplicated plain forests. According to its properties, they are close, although they have enough differences. Being common on the same plains, they create a landscape mosaic of tropical forests.
- Seasonal tropical forests grow in areas where despite good moisturizing, (2500-3000 mm), there is a dry period. The amount of precipitation and duration of the arid period in different forests of non-etinakov, among them distinguish evergreen seasonal forests (for example, Australian eucalyptus), hospital native forests (Falls are represented in the upper tier, in the lower - evergreen), bright rarely rescued forests (the floral composition is poor, it is represented by one breed). Falls seasonal tropical forests are divided into monsoon forests and savannah forests.
- The monsoon forests grow in the field of action of monsoon, the dry period lasts about 4-5 months. They are located in South and Southeast Asia, including in Indoostan, Indochita, Malacca Peninsula, in the northeast of Java Island. The forests of this type also grow in West Indies and Central America (Trinidad Island, Costa Rica) and West Africa.
- Savanne forests are common in tropical areas with a clearly pronounced dry season and the annual amount of precipitation, than in the belt of closed forests. The most part of Cuba and other islands of the Caribbean Sea, in many areas of South America, East and Central Africa and in India, China and Australia are common.
- Bready xerophilic forests and shrubs grow in areas with even less precipitation, for example, Caating, the duration of the dry season is at least 6 months.
The vegetation of seasonal rainforest
IN monsoon forests Three main groups of plant communities can be distinguished.
- In mixed forests, terminals, Dalbergia, Albia and others are dominated, the undergrowth consists of bamboo and small palm trees.
- In teak forests - teak tree (Tektona Big), leaf fall acacia lencophloea and albizzia procera and evergreen Butea Frondosa, Scheichera Trijuda, etc.
- Forests from shores of giganic, undergrowth of terminal, Sternia, etc.
Ebenic trees grow in India, Indian Lavr. Liana and epiphytes, although not so numerous, as in evergreen, but there are more than in savanna forests. Forest canopy in monsoon forests is resolved compared to the wedgeotropic forest, so the herbal cover in them is closed. Herbs are mostly annual, wild sugar cane prevails in the most dry areas.
For the upper tier of forests of this type in West Africa Triplochiton SCLEROXYLON is especially characteristic.
For savanna forests are typical of deciduous trees from the family of legumes, whose crown is usually flat umbrella. Trees have a height of 18 m. In places where the height of the trees is 3-4.5 m, in the rainy season, the trees can be above the trees. The basis of herbal cover is cereals.
In the prickly xerophilic forests there are trees with scaped leaves and shrubs with green stems without leaves. Plants are often covered with barns, stalk and roots fabrics are able to store water.
Herbs of tropical forests
In the virgin forests are inhabit the incredibly beautiful, bright, with an unusual appearance of the bird. Each individual part of the light boasts some kind of feathery. For example, in the tropics of Asia there are tourists, appearance They resemble partridges, only a little larger. They are quickly running, so in the case of danger, they do not take off, but you fly out that there are strength. Sustained chickens, pheasants, royal peacocks also live in the forests. In American tropics, you can meet Tinama - poorly flying bird with short but very strong legs. Well, how do not remember the bright, fun and talked parrots, without which the tropics are not the tropics. In addition, the Equator lives a motley pigeons, trunks, woodwoods, flies, rhinos birds and others.
Animal world
By the number of types of tropical forests, the forests of moderate and cold countries are significantly superior, the fauna of tropical rain forests is the richest, nevertheless, the number of representatives of each individual species in them is small.
As a rule, tropical forest animals live on trees, and in crowns. Mammal representatives are monkeys, flying, sloths, sovereign proteins, needles, some insectivores, predatory and so on. Birds represent parrots, woodpeckers, tucanis, hummingbirds, cranes, municipal and others; Examples of reptiles are chameleons, wood snakes, some Gecko, Iguan, Agama; Amphibians - some frogs. Many reptile poisonous.
In humidotropic forests, due to the lack of light of undergrings and herbal cover, there are few ground species in them. They are posed by tapir, rhinos, bakers, hippos. Area large mammals, including elephants, giraffes, buffaloes here are seasonal rainforests
The invertebrates are very diverse, they can be large enough, stand out by richness of shapes and coloring, among them ants, many-digging, butterflies and others.
Ecology
The result of using the covered fire farming in National Park Namdapha (India)
Tropical forests are extremely important for the planet's biosphere, they are habitating almost half of all those inhabiting it. biological species, Over 80% of all plant species. The area of \u200b\u200btropical forests is half the forest area of \u200b\u200bthe Earth. They produce 69% of all clean primary forest products of the world. Tropical forests evaporate about 9% in the water atmosphere. Despite the high biological productivity (up to 3,500 g / m² per year) and the large Opad of the leaves, the reserve of the bedding in them is significantly less than in moderate forests. This is due to both the intensity of washing in rainforests, and with the general intensity of the decomposition, and the mushrooms and termites are processed over 90% of the annual increase. vegetable substance. The rest eaten herps, which, in turn, serve as a source of nutrition for predators.
Half of the primary rainforest disappeared - instead of them, secondary forests have grown, or there are herbaceous communities that can turn into the desert. The greatest fears cause a reduction in rainpin forests. Ecosystems of seasonal factory tropics adapted both to seasonal changes and interanndible differences in the duration of dry and wet periods, so they are more resistant to anthropogenic effects. The process is exacerbated by the fact that under the cutting of forests in just 1-2 years, the nutrients from the soil in the subsoil soil occurs. The main reasons for reducing the area of \u200b\u200brainforest are:
- cutting-firing agriculture,
- burning forests for pastures,
- foreworing.
Many international organizations, such as IUCN, UN FAO, UNEP, are aware of the importance of tropical forests for the planet's biosphere and promotes their conservation. About 40 million hectares of protected territories have been created here, among them national parks Salonka and Mayco (Zaire); Zhau, 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 forest area.
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