Mangroves, or mangroves. Mangroves and mangroves

On the coast of the Caribbean Sea, in the Taiwan Strait and on other ocean coasts of the tropics, unusual coastal vegetation attracts everyone's attention. As if fleeing from excessive crowding on land, these trees, on peculiar roots - stilts, rush to the very coast, and their most courageous representatives even invade the seething waves of the warm, inviting sea.

These are mangroves. Mangroves remotely resemble the floodplain forests common in our lower reaches of the Volga, Kuban, Dnieper and Dniester during spring floods. Like our willows, sometimes flooded to the very tops with spring waters, mangrove trees generously bathe their spreading crowns in sea water. But the time of low tide comes, and the mighty waves, rolling back far, gradually expose the "underwater forest". Only drops of water on the dark green leathery leaves are reminiscent of the recent abundance of water in this forest. It is at this time that you can see the most courageous inhabitants of the mangroves in their full glory. They stand densely on their bare stilts with intense brown bark and blood-red wood due to the large amount of tannin. A real "mahogany", as the locals often call the wood of the rhizophora.

The main part of the mangrove forests is occupied by rhizophora trees. They make up their first line, the most deeply intruding into the depths of the sea. The second strip of mangroves is formed by avicenia trees. Further, "woody plants of the lagoons blow - kularia, banisteria and other species.

The adaptability of these trees (especially rhizophora and avicenia) to unusual conditions is amazing: the area, now flooded, now freed during the tides, has muddy, soaked through with salt. sea ​​water soil. There is no air in the soil at all. And the inhabitants of the mangroves perfectly adapted to such conditions. The rhizophora primarily attracts attention with stilted roots extending from the main trunk and branches and deepening into the muddy ground. Such roots often reach a height of up to 10 meters.

The method of reproduction is also different in rhizophores. They are viviparous trees. Ripe fruits do not fall from the tree, as most plants usually do, but remain hanging on the branches until a single seed of the fruit germinates. An entertaining sight is presented by the crowns of rhizophores, hung with fruits that surprisingly resemble our pears, but attached to the plant with the reverse side. These "pears" germinate with their "tail", forming the root of a "hatched" green-reddish plant. Roots from fruits grow 60-70 centimeters, gaining strength sometimes for 6 months and waiting for the right moment to separate from the mother tree. It is noteworthy that the separation of a young seedling occurs, as a rule, during the ebb of the sea. Young, fully formed plants - the new generation of rhizophores - breaking away from the fruit, rush down from the trees like an arrow and enter deeply into the soil that has just been freed from water. Here, young settlers are fixed by their rapidly sprouting roots. They only need a few hours to do this. The new tide is no longer afraid of them. By this time, they were already securely entrenched. If some of them migrate to the ground late and flounder into the abyss of the returned sea, this is also not dangerous: plant children swim well. For several months they rush along the boundless expanses of water, sometimes overcoming, like experienced sailors, very long distances and settling far from their homeland in order to quickly germinate in favorable conditions.

mangrove forests with unusual "efficiency" they form dense coastal thickets, while protecting the coast from the destructive action of sea waves. But mangroves not only protect themselves from the sea, but also systematically and continuously attack it, gradually winning back more and more territories from the water element. The dense interweaving of the roots of rhizophora and avicenia, rising above the ground at first, from day to day gradually catches silt and sand, which are continuously delivered by tireless waves. Slowly but surely, the surface of these areas rises, gradually freeing itself from sea captivity. And the arboreal inhabitants of the mangroves, spoiled by warm sea baths, do not want to lose them and, in turn, gradually advance towards the receding sea. Only the cemetery of old, dead trees - the remains of mangroves, as if a fabulous army that fell on the field of a fierce battle, densely covers the entire coastal territory, marking the cruel but victorious path of the mangrove hordes. The vanguard of their squad - the rhizophores - at that time was already "at war" with the sea on new frontiers. Often the lands reclaimed from the sea, as they are mostly very fertile, are used by people to create plantations of coconut palms and other valuable crops.

Mangroves are a favorite home for gulls, frigatebirds and many other birds. In contrast to the calm twilight of our forests, mangroves are always filled with the sound of waves and the stolid life of restless tropical fauna.

Mangroves are trees that grow in the sea. Rather, on the verge between the coast and the sea. Hence their amazing appearance- long tenacious roots, half bogged down in the silt, and half rising above the water. It is no coincidence that the roots were called "stilted".
Mangrove forests form in tropical and subtropical climates, within 30 degrees of the equator. But many species have adapted to survive in other areas that have suitable climatic and geographical conditions - the presence of tides, relatively calm waves, salty water ocean, diluted with fresh water rivers. mangroves found on the coasts of South America, Australia, New Zealand, South Africa, India, Southeast Asia.

Mangrove forests exist well on the coastline and tolerate high and low tides well. At high tide, only crowns remain on the surface, and at low tide, they are exposed long roots. The roots perform not only a supporting function, but are also the lungs of these trees - oxygen enters through the pores of the roots.
Another striking phenomenon in mangrove trees is live birth. In tightly closed fruits, small shoots with roots are born from the seed, which, when ripe, fall off and take root.

The average height of such trees is relatively low - 10-15m, so mangrove forests are often also called mangrove swamps. It is a complex and unique ecosystem. Among the intertwined roots in the water, many species of oysters, mollusks, crayfish, and crabs have found their habitat. Including jumping fish, which are very similar in principle to their “mangrove home” - they breathe both through gills under water and through the skin out of water. Many species of parrots nest in the branches, monkeys, spiders, sunbirds, bats settle. Even deer or kangaroos can find their refuge here.

Red mangrove trees have cork roots that prevent salt from penetrating from the water, and if it does, it is concentrated in old leaves, which then fall off. And white mangroves have special salt glands, so the base of each leaf is covered with secreted salt.
The black mangrove tree in the American tropics is valued for its honey production, although the honey from this tree has a specific smell.
make up about 20 species from the family of rhizophoraceae, verbena, myrisinaceae, sonnetariaceae and combreta. Each species has its own morphological features and its own adaptations for survival - it all depends on the living conditions.
Mangrove forests contribute to the formation of a fertile soil layer, thanks to falling leaves, branches that rot in the thickets and are not carried away by the tide.

Thus, mangrove trees prevent soil erosion and washing out of the banks.
AT recent times environmental and conservation organizations are actively fighting against the destruction of mangrove forests. Activists on Philippines plant young shoots and thus take care not only about the preservation of this amazing forest, but also maintain the natural balance of flora and fauna, because many "inhabitants" of mangrove forests inevitably disappear after clearing. In addition, the mangrove forest is a unique natural shield against tsunamis. It has been found that destructive tsunami 2004 became fatal for those settlements in Sri Lanka, where mangrove forest was destroyed. And there is another property that is important for the environment - this is the ability to absorb salts of heavy metals from water.

Evergreen tropical mangroves are a truly amazing creation of nature. These unique trees, forming entire groves and forests, exist on the border of land and sea. At high tides, such forest kingdoms are hidden by sea waters, and only the tops of these trees rise above the water, because of which at such moments one can think that these are emerald islands. But then the tide comes, the water recedes, and bizarre, as if from a fairy tale, trees are shown.

Mangroves - lovers of tropical latitudes

Mangrove trees reach a height of 10-15 meters (in the Eastern Hemisphere there are mangrove trees up to 30 meters high), grow obliquely and have a powerful root system that does not allow ocean currents to wash them out of marshy soil. According to one version, the origin of the name of these tropical trees is precisely due to the specifics of their growth, because in Portuguese “mangroves” means “crooked grove”. The Greek navigator Nearchus, who became the first European to see mangroves, called them "forests growing in the sea."

Mangrove trees are common in places with a tropical and subtropical climate and grow exclusively on salty soil, on sea coasts, which are constantly flooded with water during high tides. At low tide, the soil dries up and the salt content in it increases, but mangroves are able to withstand significant fluctuations in their concentration.

Mangrove forests are widespread in various parts of the world. These amazing trees grow on the muddy coast of South Africa and at the mouth in South America, on the island of Madagascar and on Atlantic coast Brazil. Mangrove forests are also common in New Zealand and on the northern coast of Australia, in India and Southeast Asia, in Cuba and Indonesia, on the coast of many Caribbean islands, in Florida, in southern Japan and in Bermuda.

In India, mangrove trees are found mainly in floodplains and river deltas, while Bangladesh has the world's largest mangrove. In total, there are about 54 species of mangrove trees, and their greatest diversity is found on the coast of Southeast Asia.

Such a wide distribution of these tropical trees around the world is due to the peculiarity of their seeds, which ripen on the trees themselves, after which they fall off and are carried away by the flow of water to future germination sites. Mangrove seeds are able to swim in the seas-oceans for a long time (up to a year), until they find their harbor, where they take root.

Flora and fauna of mangroves

Very little light penetrates into dense mangrove forests, which, combined with being in a zone of constant tides, makes lower tiers these rainforest absolutely unsuitable for the germination of any vegetation.
But the upper tiers of mangrove forests are rich in flora and fauna.

The branches of mangrove trees are the abode of various epiphyte plants (for example, Louisiana moss) and the realm of spiders weaving their extensive webs on them. Typical representatives of tropical forests live in the mangrove crown: parrots, monkeys and bats. Also, these impenetrable swampy forests become the abode of many species of birds. Storks, herons and pelicans nest here.

Typical inhabitants of the root system of mangrove trees include fiddler crabs, numerous species oysters, water snakes, crabeater frogs and unique tropical fish - mudskippers.

These small fishes are distinguished by a long (from 10 to 27 cm) body and the ability to move on land with quick jumps, while resembling the movement of abandoned pebbles on water. The specificity of these fish is that they spend most of their time out of the water, staying on the coast during low tides. They either sit in holes with water, or hunt for small crabs and insects.

In addition, mudskippers can crawl up a tree trunk to human height. They are distributed mainly in the tropical regions of the eastern Atlantic, as well as in the eastern and western parts of the Indian Ocean.

Significance of mangroves

Mangrove forests form a unique ecosystem that protects the coast from soil erosion. The tenacious roots of mangroves bogged down in the silt allow these trees to withstand even ocean storms, which makes such forests a natural barrier protecting the coast from the destructive elements.

Currently, mangrove forests around the world are protected areas. In many countries where they were previously cut down, they are now striving to revive this unique ecosystem by planting new mangrove trees that will create new groves at the crossroads of land and sea.

In the Taiwan Strait, on the Caribbean and other ocean coasts of the tropics, unusual coastal vegetation attracts everyone's attention. Trees with peculiar roots, as if escaping from the cramped land, rush to the very shore, and the most daring of them even invade the waves of the seething warm sea. These are mangroves.

Description

Such thickets are somewhat reminiscent of floodplain forests common during spring floods in the lower reaches of the Volga, Dnieper, Kuban, and Dniester. Like our willows, sometimes flooded with spring waters to the very tops, mangrove trees generously bathe their spreading crowns in sea water. But the time of low tide comes, and powerful waves, rolling back far, gradually expose the "underwater forest". Only drops of water on leathery dark green leaves testify to recent water abundance. Just at this time, you can see each mangrove tree in all its glory. Plants stand densely on bare stilted roots with brown-colored bark and blood-red wood (due to the high content of tannin).

Mangrove trees are a favorite home for frigatebirds, gulls and many other birds. Their thickets, unlike our calm forests, are always filled with the sound of waves and the stolid life of tropical restless fauna.

Variety of species

Mangrove tree - evergreen, growing in the sea, more precisely on the border of the coast and water. Hence its amazing appearance - tenacious long roots, bogged down in the silt half and half rising above the water. It is no coincidence that they received the name "stilted".

Mangrove forests are represented by plants numbering about twenty species from the families of verbena, rhizophora, combret, myris, sonnetaria and others. They form in the subtropics and tropics, within thirty degrees of the equator. However, many tree species have adapted to life in other areas where suitable geographic and climatic conditions, such as the presence of tides, the salt water of the ocean diluted with fresh water of rivers, relatively calm waves.

reproduction

The mangrove tree is viviparous. The fruits, when ripe, do not fall from the branches, as in most plants, but continue to hang until a single seed sprouts and the roots of a new tree are formed. Such roots from hanging fruits grow 60-70 centimeters, sometimes they gain strength within six months and, as it were, wait to separate from the mother plant at the most favorable time. It is noteworthy that young mangrove trees are usually separated at the time of low tide. Fully formed seedlings rush down and pierce into the soil, just freed from water. So the new generation begins an independent life.

Biological features

At high tide, when flooded by the sea, the mangrove tree takes on a very peculiar appearance. If during this period you look at the forest from the sea, it looks like a floating green dense mass. When the water recedes from the coast, tall and short plants begin to stand out with numerous aerial curved roots exposed. These respiratory organs serve as a support on muddy unsteady soil, which has little aeration and is very poor in oxygen. Interestingly, stilted roots hang not only from the trunk, but even from the lower and upper branches, they often branch out, which makes the plants especially resistant to storms.

Being in sea salt water for quite a long time, the mangrove tree not only successfully resists the force of winds and waves, but also fights against the oversaturation of plant organisms with salts. It also fights for an increase in oxygen, which is difficult to access in silty soil, but is so necessary for the roots.

Where does the mangrove tree grow?

These amazing plants spread out in a discontinuous narrow strip along the sea coasts in the tropics. They form dense thickets in estuaries, on muddy gentle banks and in the lagoons of Africa and America, Australia and Southeast Asia. The mangrove tree can be seen on many islands, including Madagascar, Cuba, the Philippines, and Indonesia.

Such forests are common in Australia along the northern coast, especially on the shores of the Gulf of Carpentaria.

In India, mangroves grow in the deltas and floodplains of the Ganges, Godavari, Brahmaputra, and are also found in the tidal zone of some gentle coasts. Mangrove forests in Bangladesh occupy half a million hectares, they are typical of river deltas and the coast of the Bay of Bengal. In Burma and Sri Lanka, such trees stretch in a strip along the muddy low-lying banks.

In Vietnam, mangroves spread over an area of ​​about three hundred thousand hectares along the southern coast of the sea, and among them you can find more than fifteen tree species. A similar composition of mangrove forests in Malaysia.

Along the coast of Africa, green groves of coconut palms are common, and along the Atlantic Ocean, along the gentle, muddy shores, mangrove trees grow, widely represented by rhizophora, which either forms pure stands or mixes with canocarpus and avicenna.

Mangrove forests in Brazil are also characteristic of the Atlantic coast. They are also found at the mouth of the Amazon River. Their typical representatives, as in Africa, are the rhizophora (red mangrove), avicennia (black mangrove) and undersized canocarpus (white mangrove).

The fight to save the amazing forest

Conservation organizations have recently been actively fighting against the destruction of the mangrove forest. In the Philippines, activists plant young shoots and in this way take care not only of preserving unusual plants, but also of maintaining the natural balance of flora and fauna, since many of their inhabitants inevitably disappear following the cutting down of mangrove forests.

In addition, such vegetation is a unique natural shield against tsunamis. Thus, it has been established that the devastating tsunami in Sri Lanka in 2004 was fatal for those settlements where the mangrove forest was destroyed. Another property of these trees that is important for ecology is the ability to absorb salts of heavy metals from water.

Mangroves, mangroves (from the English mangrove), are tree and shrub plant communities that develop on periodically flooded areas of sea coasts and estuaries, protected from surf and storms by coral reefs or coastal islands. The Greek navigator Nearchus, who reached in 325 BC. northern border of the mangroves in the Persian Gulf, called them "forests growing in the sea."

Mangroves are distributed mainly in the humid tropics - on the coasts of East Africa, South Asia, Australia and Oceania. And on western coasts Africa and the tropical shores of America are almost never found. The most northerly distribution point of mangroves is about 32°N. in Florida and Bermuda, in the Red Sea (Gulf of Aqaba) and in southern Japan. In the Southern Hemisphere, mangroves move even further from the equator. On the east coast of Africa, they reach the vicinity of Durban (33 ° S), and in Eastern Australia - 38 ° S. The least extent of the mangrove range is on the Pacific coast of America, from Baja California to 3 ° 48 "S in South America - to the south, its distribution is limited by the cold Humboldt Current. In the Atlantic Ocean, mangroves reach 28 ° 20" in southern Brazil. On the coast of Africa, they are confined mainly to estuaries. major rivers, and their spread to the south stops at about 9°S. dry, almost desert climate of the continent. Thus, from the point of view of zoogeography, mangrove biocenoses are considered intrazonal.

During low tide, the soil in the mangrove area dries up and the salt content in it increases several times. Mangrove trees have the ability to tolerate large fluctuations in the concentration of salts (mainly table salt) in the soil. Their roots absorb desalinated water through ultrafiltration. The fluid entering the vessels of mangrove plants contains only about 0.03% salt. Nevertheless, salt accumulates in tissues, especially strongly in old leaves due to prolonged transpiration. Mangrove leaves are juicy, but at the same time tough and leathery.

tree species, composing mangroves, have strengthening stilted roots and rising from the ground upwards (negative geotropism) respiratory roots-pneumatophores. Their fruits are usually supplied with air-bearing tissue and can float in water for a long time.

Mangroves usually consist of evergreen trees 10–15 m high. The tallest trees (up to 27–30 m) are found in the mangroves of the Eastern Hemisphere. Depending on the frequency and duration of flooding, the nature of the substrate (silty or sandy), the ratio of fresh and sea water (at river mouths), plants in mangroves are located in belts, each of which is dominated by one or two (sometimes several) species. The number of plant species that form mangrove thickets is relatively small - about 20 species belonging to the families of rhizophoraceae, verbena, myrisinaceae, sonnetariaceae and combretaceae. In the family of rhizophoraceae (Rhizophoraceae), representatives of 4 genera are best known: rhizophora (Rhizophora), brugiera (Bruguiera), ceriops (Ceriops) and candelia (Kandelia) - they form the bulk of mangroves.

Mangroves, forests flooded with water during sea tides - a symbol of tropical coasts. This mangrove tree belongs to the Rhizophora genus. Bako National Park, Sarawak. http://www.equator.ru/photo-forms/1999_borneo_sarawak/99gall15.htm Rhizophores, as a rule, are small trees or shrubs, but some of them can reach a height of 30–40 m. The root system of mangrove rhizophores is shallow, extended in the upper layers of the soil. Many species have the ability to form adventitious supporting (so-called stilted) roots on the lower part of the trunk and lower branches. Sometimes in rhizophora, plank-shaped roots are also formed, which give stability tall trees, since with their help the mass is evenly distributed over a large area of ​​\u200b\u200bsupport. Species of the rhizophora genus, as a rule, are pioneering mangroves growing from the seaward sides and taking on squalls of wind and wave blows. During high tide, sea water often floods them to the very crowns, and low tide exposes trunks and a dense plexus of roots. The trunks of such trees rarely stand upright, more often they are located obliquely or almost horizontally, relying only on stilted roots, which in representatives of this genus also appear on the lower branches. Upon reaching the soil, the stilted roots usually branch out, giving the trees additional stability during storms. The bark of trunks, branches, and adventitious roots is provided with lenticels connected with the intercellular spaces of internal tissues, and through these lenticels, as well as through stomata, gas exchange occurs during low tide.

Species of the genus Brugiera, on the contrary, gravitate towards drier, inland areas of mangrove thickets, where they form exceptionally dense straight-stemmed forests, under the canopy of which twilight constantly reigns. In brugiera, horizontal roots extending radially from the base of the trunk form high vertical knotty and clumsy cranked outgrowths sticking out of the ground. Their lower part, immersed in the soil, bears numerous nourishing roots, while the upper part grows in height over the years and is covered with a cork-like crust, through the pores of which oxygen is supplied to the tissues of the root system.

Rhizophore flowers are collected in small primrose inflorescences, sometimes solitary (in leaf axils), usually bisexual. The petals are dull, often white, yellowish or brownish. Pollination occurs mainly with the help of wind. But in Brugiera, the abundant nectar-producing flowers attract hawk moths and other insects, as well as nectary birds. Hard woody fruits of rhizophoraceae contain one seed. In unusual ecological conditions of growth, these plants developed a special property - live birth (viviparia), that is, the germination of a seed in a fruit still hanging on the mother plant. The rhizophoral embryo begins to develop immediately after fertilization. After 11–13 weeks, it breaks through the fetal wall and continues to grow vigorously. In rhizophora spiky, such hanging seedlings reach 1 m in length, which is why these plants are called "candle trees". The seedlings remain on the tree for 30–39 weeks, sometimes whole year and then fall vertically down. If the soil under the tree is soft silt, the seedlings stick into it and due to this they are not immediately carried away by tidal currents. On denser soil, fallen seedlings remain on the surface and take root lying down, gradually rising. Often at the same time, some of them dry up in the sun, while the other part is carried away by water into the sea.

Carried away by the sea wave, rhizophoral seedlings can make long-term (up to a year) sea ​​travel while maintaining viability. This is the main factor that ensures the wide distribution of rhizophorans on tropical sea coasts. In some places they cross the line of the tropics, where warm currents and climate favor the development of mangroves. Thanks to the mangrove rhizophora, islands arise, which first grow singly in shallow water, and then gradually merge.

The economic importance of rhizophora is small. Their wood serves as fuel, is used in construction, mainly for piles, sleepers, beams in underwater and underground structures. It is heavy, hard, durable, little affected by shellfish. The bark of mangrove rhizophora, containing up to 40% tannins, is used in leather production and for the production of dyes.

The verbena family (Verbenaceae) includes species of the genus Avicennia (Avicennia) - the most characteristic plants of mangroves in almost all tropical countries. At the same time, avicenna is more resistant to winter cold than other mangrove trees, and in the Southern Hemisphere (in New Zealand) it goes further south than other species. Like other mangroves, Avicenna has special respiratory roots - pneumatophores growing vertically upwards, protruding from the silt at low tide and supplying the underground parts of the plant with oxygen through a system of holes located at the ends, connected with the intercellular spaces of the root. Seed germination of Avicenna, as in rhizophora, begins already on the mother plant, and the falling one-seeded fruits bear a fully developed seedling. In nature, Avicenna species often replace mangrove rhizophora.

The Myrsinaceae family includes the genus Aegiceras, one of the representatives of which, A. corniculatum, is one of the common plants protected from the surf of mangrove forests on the muddy coasts of the Indian and Pacific Oceans, from India and Sri Lanka to South China and Northeast Australia. Another species of the genus, flowering aegitseras (A.floridum), is found only in Melanesia.

Aegicerases are shrubs or small trees no more than 8 m high, with respiratory pneumatophore roots that supply the plant with oxygen, with leathery leaves, often covered with salt crystals secreted by special salt glands. Aegiceras grow mainly in swamps along the banks of rivers and estuaries and are confined to the inner zone of mangroves, where the influence of salt water is less felt. As in rhizophora and avicenna, the only large elongated seed of Aegiceras germinates without a dormant period, still in the fruit hanging on the tree. But the seedling breaks through the shell of the fruit only after it has fallen off. The fruits of these plants are carried by sea water. In addition to Aegiceras, other myrsine species are also found in mangrove thickets - elliptical erdisia (Ardisia elliptica), umbrella rapanea (Rapanea umbellulata), etc.

The Sonneratiaceae family includes 5 species of the genus Sonneratia, which grow in mangroves on the sea coasts of East Africa and Madagascar, Tropical Asia to the islands of Hainan and Ryukyu, Micronesia, the Greater and Lesser Sunda Islands, Northern Australia, and New Guinea , Solomon Islands and New Caledonia. The most widespread are white sonneria (S. alba) and cheese sonneria (S. caseolaris). Sonnerathiaceae are evergreen trees 15–20 m high, sometimes more. On their long horizontal roots, numerous vertical outgrowths sticking out above the soil surface are formed, covered with loose bark with abundant intercellular spaces and bearing many small feeding roots, which are formed anew in the upper part as silt and sand accumulate. This is the main function of the vertical outgrowths that form in the soil flooded by the tides - the constant removal of the feeding roots to the upper fertile layers.
The flowers of the sonnerathiaceae are quite large, bisexual, arranged in 1-3 or in small inflorescences-scutes. Petals in some species are absent or inconspicuous. Flowering is night, short-term, at dawn the petals and stamens fall off. The flowers emit an unpleasant odor, secrete abundant nectar and are visited in the evening and at dawn by nectary birds, and at night by nectar-eating bats.
The fruits of sonnetratiaceae are berries that quickly rot on the surface of the soil. The seeds are then dispersed by water and germinate on beaches and coral terraces. The wood of the sonnerathiaceae is brown-black, heavy, and quite strong. locals sometimes it is used in the construction of houses and for the manufacture of boats.

The upright conocarpus (Conocarpus erectus) belongs to the Combretaceae family (Combretaceae), a small evergreen tree found on the coasts of the Atlantic Ocean. Conocarpus gravitate toward the interior of the mangroves. As the soil washed by the tides grows, this plant forms adventitious roots in the lower part of the trunk.

Mangrove forest in Australia. So little light penetrates inside the mangrove forest that the lower tiers of vegetation are practically absent. This is also prevented by significant fluctuations in the water level and semi-liquid soil. But at the top, on the branches of the mangroves, epiphytic plants, such as Louisiana moss, or Tillandsia usneoides, a flowering plant similar to the lichen, from the bromeliad family, can settle. Tillandsia is an epiphyte from the group of so-called "atmospheric" bromeliads, it receives everything it needs from the air. Its root system is completely absent (with the exception of seedlings), the plant absorbs moisture directly from the air, and mineral salts from rainwater and airborne dust. The branchy shoots of Tillandsia usneiform reach 8 m.

Mangroves are characterized by high productivity. At the same time, in places where they grow on the coasts of tropical seas, in bays and estuaries of rivers, silt and sand are deposited. In internal parts mangroves, real soil is already formed - as a result of mixing sea silt with the remains of leaves, branches and trunks of mangrove trees, humus is formed here, and sometimes even layers of peat. The rich detritus produced by decaying leaves and wood provides the basis for new food chains that parallel or intertwine with normal food systems that begin with phytoplankton. The creation of physical habitats, especially a huge network of protected waterways, has great importance for many small animals of the shallow continental shelf. Among the inhabitants of the mangroves, crabs are numerous. Oyster species and other bivalve species are also abundant in the lower, flooded areas, and a variety of gastropods attach themselves to trees above the intertidal zone, holding tighter in areas completely flooded with water. In open spaces among the roots of trees and above, in their crowns, various spiders weave their webs, sometimes reaching almost 2 m in diameter.

Fish from the family of mudskippers (Periophthalmidae) can be considered very characteristic inhabitants of mangroves. This family includes 3 genera and 10–12 species of small (with a body length of 10–27 cm) fish distributed in the tropical regions of the eastern Atlantic and Indian and western Indian Oceans. Mudskippers have a valky body and a large, round-browed head with retractable, bulging eyes. The bases of the pectoral fins of these fish are muscular, and the fins themselves are long and wide. Mudskippers live in the littoral, most often near the mouths of rivers, in calm bays and lagoons with a muddy bottom. They spend a significant part of their lives out of the water, staying on the shore at low tide. In addition to breathing through the gills, these fish are able to absorb oxygen directly from atmospheric air through the skin. The peculiar structure of the pectoral fins allows jumpers to move on land with fast jumps. They can also jump on the surface of the water without sinking to a depth, while the movement of the fish resembles a thrown pebble jumping on the water.

At low tide, mudskippers either sit quietly in water holes with their heads and pectoral fins out into the air, or actively hunt for small crabs and aerial insects. At the same time, they often climb onto snags and mangrove tops protruding from the water - clasping a thin branch with their pectoral fins and resting their tail, these fish can crawl to a rather large height (above human height). The ventral sucker allows jumpers to hold on to almost vertical tree trunks and rocks.

Mangrove crowns are often inhabited by typically terrestrial animals - parrots, monkeys, etc.

The formation of mangroves significantly affects the living conditions of bottom dwellers. Due to the abundance of organic residues in the soil here, already a few millimeters from the surface, there is no free oxygen. Where the parent rock is not formed by calcareous deposits, but consists of weathering products of volcanic rocks, a large volume of hard-to-destroy wood fibers leads to the formation of humus, humic acids and even peat in the silty soil. The consequence of this is the high acidity of soil water, and sometimes the water in the channels that cut through the mangroves. Since sea water is alkaline, water with a pH of 6 to 7 is a very unusual environment for marine animals. For example, for mollusks, this means difficulties in the formation of a calcareous shell.

To environmental group decomposers of wood of mangrove trees belong to the mollusk shipworm (teredo) and drilling crustaceans (Sphaeroma) from the order of isopods. They begin the mangrove destruction cycle, which ends with marine fungi and bacteria. Without the activity of decomposers, the banks would be littered with a huge number of dead trees. Sometimes shipworms and crustaceans attack live mangrove trees. This promotes natural thinning of the thicket, keeps the waterways open within them, provides continuous access to nutrients, and prevents excessive accumulation of rotten trees.

South Sinai offers travelers quite a few unique natural gems. One of them is, undoubtedly, a marine national park Ras Mohammed, which has no equal in the Northern Hemisphere in terms of the quantity and quality of corals, marine life and fauna. Ras Mohammed Marine National Park ranks third in the world in terms of the beauty of the underwater world, yielding the first two steps of glory only to the Australian Great barrier reef and famous Maldives.

Ras Mohammed Marine National Park is located just 25 km from the popular Egyptian resort of Sharm El Sheikh on the southernmost point of the Sinai Peninsula, at the point where the Arabian and Suez Gulfs meet. Ras Mohammed, opened in 1989, covers an area of ​​480 square meters. km, two thirds of this area is the sea. Most visitors to Ras Mohammed come here to enjoy the vibrant underwater scenery. However, we came to the Ras Mohammed National Park, first of all, to see very unusual plants - mangroves.

Mangrove plants are found on the border of land and sea along the tropical coast of the whole the globe- the coasts of East Africa and South Asia, Australia and Oceania. One of their places of growth is Egypt, where you can see mangroves in the national parks of Ras Mohammed and Nabq.

The first mention of mangroves was left to us by Nearchus, one of the commanders of Alexander the Great, back in 325 BC. During his voyage from India to Mesopotamia, Nearchus found thickets of unknown plants in the Persian Gulf, which he called "forests growing from the sea." It is believed that the name of these plants - "mangroves" (mangrove) came from the merger of two words: the Portuguese mangue - which means "curve", and the English grove - "grove". Dozens of species of mangrove trees and shrubs that exist on our planet are united by a unique ability to grow on saline soil, very poor in mineral elements, periodically covered by tides. Mangroves are native to Southeast Asia. Greatest variety Mangrove plants in modern times are distinguished by the southern coast of the island of New Guinea.

Mangrove plants are a group of diverse evergreen trees and shrubs that have developed a set of physiological adaptations that allow them to survive on muddy, periodically flooded areas of sea coasts and estuaries, in conditions of low oxygen content and rather high salinity of water. Mangrove plants are characterized by the presence of such morphological features as salt glands, succulent leaves and ultrafiltering roots. Intertidal adaptations developed by mangroves are virtually non-existent or extremely rare in communities of other plant types.

Mangroves are represented by 54 species from 20 genera belonging to 16 families. The most common types are red, black and white mangroves. Mangroves are under water on average up to 40% of the total time. Sea tides often flood plants to the very crown. Mangrove nutrients are obtained from salt water, while purifying it of organic impurities and other harmful substances.

In red mangroves, the roots of the plant desalinate more than 90% of the water using a kind of ultrafiltration mechanism. After passing through such a root “filter”, the water contains only about 0.03% salt. All the salt entering the plants accumulates in the old leaves, which the plants then discard, as well as in special cell vesicles, where it no longer causes any harm to the plant. White (sometimes also called gray) mangroves can excrete salt due to the presence of two salt glands at the base of each leaf. The leaves of these plants are generously covered with white salt crystals. True, we did not manage to see such crystals on the leaves, because three days before our arrival, a very rare guest of the desert, rain, took over in these places.

To limit the loss of life-giving moisture through the leaves, mangroves have also developed special mechanisms. So, for example, they can limit the opening of stomata on the leaf surface, through which the exchange of carbon dioxide and water vapor occurs during photosynthesis; in addition, during the day, to reduce evaporation of moisture, mangroves turn their leaves in such a way as to avoid hot sunlight as much as possible.

Since mangroves live in places where the soil is poor in nutrients, these plants have changed their roots to obtain the maximum possible nutrients. Many mangroves have developed a system of aerial or stilted roots that anchors the plant in semi-liquid silt and allows it to obtain gaseous substances directly from the atmosphere and various other nutrients from the soil. There is also a process of accumulation of gaseous substances in the roots, so that they can be processed later when the roots of the plant are under water at high tide.

In a very original way, nature also took care of protecting the reproduction of the genus of mangrove plants. All mangroves have floating seeds adapted to disperse through water. Many mangrove plants are viviparous, and before they have separated from the tree, their seeds begin to germinate. While the fruit hangs on the branch, a long sprout sprouts from the seed, either inside the fruit or through the fruit to the outside. The seedling formed in this way can feed on its own with the help of photosynthesis, and when it matures, it rushes down into the water. Water is the main means of its transportation. For full maturation, the seedling needs to stay in the sea for at least a month. During their sometimes very long voyage, seedlings are able to endure desiccation and remain dormant for even more than a year - until they get into a favorable environment.

When such a seedling - a traveler is ready to take root, he begins to control his position in the water, changing his density in such a way as to “turn over” and take a vertical position in the water - bud up, roots down. In this form, it is easier for him to stick into the mud and start life in a new place. If the seedling fails to take root in this place, it is able to change its density again and set sail again on a new journey in search of more favorable conditions. But quite often the seedling grows so long that it reaches the dirt before the fruit has even fallen.

Mangroves are a separate complex ecosystem. Mangroves hold back salinization of coasts and resist coastal erosion. Their fallen leaves serve as food for all kinds of microorganisms at the beginning of the food chain. Aerial roots, flooded with water, become a refuge for many small fish, shrimps, crabs and various marine microorganisms. Many species of migratory birds find nesting and resting places in mangrove thickets, which are difficult for humans and large animals to access. Parrots and monkeys live in the crowns of mangrove trees. The leaves of some mangrove plants are eaten by terrestrial animals.

Once upon a time, mangrove plants occupied almost two-thirds of all coasts in the tropical latitudes of our planet. Today, the mangrove area is shrinking at an alarmingly increasing rate, humanity has already lost more than half of its world's mangrove forests.