Mountains - dark coniferous forests of the Caucasus. Coniferous trees in an urban environment Largest tree by volume: General Sherman

Chapter 39 They will create a whimsical style with their shape, color ornament, leaf pubescence. Ask at the flower shop

Conifers: ordinary ... There are two large divisions of seed plants: angiosperms and gymnosperms. For angiosperms characterized by the presence of flowers and fruits. Their seeds are protected by the walls of the fruit, which develops from the ovary of the flower. In gymnosperms

Chapter 9

Normally, living beings, including us, have a period of active growth in youth, but as we age, growth body slows down or stops altogether. The growth rate of trees in height has the same character. After a period of active growth in height, the growth rate of the tree decreases, and it begins to gain mass due to the trunk and side shoots. The figure shows general character dependence of the height of the majority of the tree on its age. The schedule is divided into three phases. 1 is initial phase slow growth, followed by a phase of rapid growth - 2. When the tree approaches a certain height, growth rates fall - phase 3. Of course, the values ​​of time and height will be different for each individual tree, depending on the characteristics of the species and environmental conditions.

The general nature of the dependence of the height of most trees on age

Different types of trees grow from different speed. Depending on the growth rate, trees are usually divided into groups. In tables 1 and 2, the trees are divided into groups depending on the rate of tree growth per year. Trees gain such growth rates during the active phase (at the age of 10 to 30 years).

Table 1: Fast growing and moderate growing trees

Table 2: Slow growing trees

Tree Mass Growth Rate

It used to be thought that large trees were less productive at capturing carbon dioxide. However, recently, on January 15, 2014, research data was published in the journal Nature, indicating the opposite. The study was conducted by a team of international scientists led by Nate L. Stephenson of the American Environmental Research Center (Western Ecological Research Center).

The scientists reviewed research records from six continents collected over the past 80+ years, based on repeated measurements of 673,046 individual trees.

“Large, old trees act not only as aging reservoirs of carbon, but also actively sequester a large amount of carbon compared to small trees ... In some situations, one large tree can add as much carbon to the forest mass in a year as is contained in the entire medium-sized tree ".

The main problem is the perception of scale. Stevenson says it's difficult to see the growth of a large tree because it's already huge. With age in thickness the tree adds less, but the larger the diameter, the more surface area grows. A tree can grow in height over many years, but at a certain point it reaches its peak and then begins to increase in trunk diameter, increases the number of branches and leaves.

The researchers write:
“Most likely, the rapid growth of giant trees is the global norm and can exceed 600 kg per year in the largest specimens.”

Stevenson also says that if people grew at this rate, they could weigh half a ton in middle age, and well over a ton by retirement.

The figure shows the general nature of the dependence of the tree mass growth rate on the decimal logarithm of the tree mass, given in the article.

As a result of human activity and for other reasons, vast areas of ancient forests are being destroyed. . Trees play a very important role in existing ecosystems, so it is vital for us to protect forests from destruction.

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When a person climbs a high mountain, he feels that the temperature drops and the climate becomes more humid. About the same climate change he would feel, driving from the tropics to the pole. This climate change is also reflected in the mountain vegetation. In any country of the globe, the plants on the mountain slopes are more similar to the flora of the countries closer to the poles than to the vegetation of the plains surrounding these mountains.

Of course, the same thing grows at the foot of the mountain as around it: in the tropics - impenetrable, dark jungles, in the subtropics - evergreen laurel forests, in the temperate zone - deciduous forests of beech and oak or birch and aspen, and in more northern places - coniferous forests. As they ascend, the types of vegetation of higher and higher latitudes gradually pass before the gaze of travelers.

For example, the Himalayas lie close to the tropics; at an altitude of 1000 m, the tropical jungle gives way to subtropical laurel forests there; from 1500 to 2000 m there are walnut, oak and beech forests; at an altitude of about 2500 m they are replaced by coniferous forests - fir, spruce, pine; The upper edge of the coniferous forest lies at an altitude of 2900 to 4300 m.

The farther the mountains are from the equator, the lower the corresponding types of vegetation are located on them. In the Caucasus and on the Central Asian ridges, coniferous forests grow at an altitude of 1500 to 2300 m, and in Altai these forests cover the foot of the ridges.

The mountain forest is very similar to the vegetation of the plains of a certain latitude. The beautiful oak forests of the Caucasus resemble Central Russian oak forests, and in the dark forests of Caucasian fir it is easy to imagine that you are in the West Siberian taiga.

The spruce forests of the Tien Shan, interrupted by green meadow glades, look like spruce forests in the middle zone of the European part of the USSR.

However, there are significant differences between mountain and lowland forests. The closer to the equator, the higher the sun rises above the horizon in summer.

In summer, the air temperature in the zones of the mountain slopes is the same as in the plains of the corresponding latitudinal zone, but the winter on the southern mountains is shorter than on the northern ones.

The share of coniferous forests in the north of the Soviet Union accounts for only 3-4 summer months a year, while in the mountains of the Caucasus and Central Asia for fir and spruce forests, summer lasts 5-6 months. Therefore, mountain vegetation cannot be identified with the vegetation zones of higher latitudes.

Above the strip of coniferous forests, where there is no longer enough heat or food for trees, the mountain slopes are covered with characteristic vegetation, which is not found on the plains. True, it resembles the meadows and tundras of the North, but it has so much of its own, characteristic that it is difficult to confuse it with anything else. This alpine vegetation was first studied in detail in the Alps and was called alpine meadows. The more lush part of the alpine meadows, located just behind the coniferous forest, is often called subalpine meadows to distinguish them from the typical alpine ones lying even higher.

The high mountain climate is quite severe. But the transparent mountain air lets in much more sunlight than on the plains. During the day, alpine plants are well lit and strongly warmed by the sun's rays. After sunset, the overlying snow begins to blow cold, the air temperature drops and the earth cools quickly. In the mountains, night colds and severe frosts are common even in the middle of summer. Summer in the zone of alpine meadows is relatively short: the snow melts only under the direct rays of the summer sun. Closer to autumn, the sun can no longer heat the mountainside that has cooled overnight. Fog hangs over the mountain meadows, and then snow falls.

In the Caucasus, the Alps, the Carpathians, alpine plants can grow for only six months, in the Tien Shan for 4-5 months, and in Altai for 2-3 months. In the tropics, alpine meadows do not know winter rest, since the temperature drops here only at night, and does not fall below -10 °. However, on the ridges remote from the equator, the temperature in the winter months drops from -20 to -50 °. This climate is somewhat reminiscent of the tundra. But in mountain soils there is no permafrost, so there is neither accumulation of soil moisture nor waterlogging, which is characteristic of the tundra. In addition, in the summer in the mountains of temperate and tropical latitudes there is no polar non-setting sun, and the day here is relatively shorter than in northern latitudes. Rainfall is higher in the mountains than in the tundra, and sunlight is more intense.

The subalpine belt is a lush, tall grass meadows or thickets of mountain shrubs. The subalpine zone in the Caucasus is especially good. Here the mountain tall grass is very majestic.

Tall grass meadows stretch in a wide strip along the coniferous forest zone in the Caucasian Reserve (north of Sochi), in South Ossetia and Colchis. The grass here grows up to 2.5 m and covers even the rider on a horse. Most grasses are perennials: they use little heat better than others and develop faster in spring. Violet geraniums, blue bells, yellow elecampane and digitalis, blue aconites and larkspurs grow here. Huge white umbrellas of hogweed and yellow flowers of lilies rise among them. Only in some places tall grasses are mixed in: a huge hedgehog, timothy, fescue. Particularly interesting is Kupriyanov's perennial rye, a close relative of cultivated rye. It occupies vast glades in the Caucasian Reserve and produces good grain, which is sometimes used by local residents.

On the ridges of Central Asia, the climate is drier. Here in the subalpine meadows there are more cereals, and they are undersized: wheatgrass, bluegrass, fescue, wild oats, fires, foxtails. Against the background of cereal thickets, broad-leaved bushes of mountain goat grass with large plumes of purple flowers and mountain meadow geraniums with pinkish-lilac flowers stand out. Bluebells, pink scabioses, blue gentians, orange-yellow, like fire, bathing suits grow here, pinkish-white large spikes of buckwheat-throat flowers sway. In the Altai subalpine meadows, large-flowered buttercups, larkspurs, aconites, saplings, geraniums, cuffs, and sorrel predominate. Of the cereals, hedgehogs and perennial oats are common.

Thickets of shrubs are interspersed in the meadow subalpine flora. Thickets of rhododendron and azaleas with an admixture of crowberry and blueberry are especially characteristic of the Caucasus. In spring, these thickets bloom and the air is filled with aroma. Creeping forms of willow and pine are also common here.

Above the subalpine meadows, short-grass alpine meadows begin. It's getting cold here for the plants. The height of alpine grasses is from 10 to 30 cm, but their roots are strongly developed, forming a dense turf. Almost all of these plants are perennials. An annual plant would not have time to develop properly before autumn, and a perennial plant immediately, as soon as it becomes warm, begins its full life: it blooms and bears fruit.

Many alpine herbs reproduce vegetatively: by rhizomes, offspring, shoots from roots. Shrubs in alpine meadows are also undersized, they branch profusely. Numerous and short branches make the surface of their crown even, and the shrub looks like a round pillow lying on the ground. This structure protects it from excessive evaporation of moisture and sudden temperature fluctuations.

Low-growing alpine meadows are extraordinarily beautiful. Groups of large flowers of various shades are scattered across emerald glades, and eternal snows of mountain peaks sparkle above the glades. The main background of alpine meadows is sedges growing in dense bushes, and grasses (shakers, bluegrass, fescue, white-bearded, cobresia). Blooming bushes of alpine clovers are scattered against this background. Mountain anemones, poppies, violets, gentians, buttercups, alpine asters bloom. All of them are squat and large. Bright coloring helps to attract insects that pollinate alpine flowers, which are very rare in the mountains.

Scientists tried to sow early crops in the mountains. The color of the stems, leaves and flowers of these plants was unusually intensified. Peas, flax, poppies bloomed much brighter in the mountains than on the plains. Even the roots of radishes and tubers of pink potatoes grown in the meadows near the snowy peaks of Fisht and Oshtein in the Caucasus Reserve looked much brighter than usual.

The high mountain climate contributes to the fact that alpine plants bloom luxuriantly and for a long time. Frost and snow stop flowering, but do not harm flowers and buds. The heat is on and the bloom continues. So all summer blooms, for example, alpine perennial poppy, alpine strawberries bear fruit all summer. Low-growing grasses of alpine meadows are extremely nutritious. Livestock, even exhausted by heavy wintering, is growing rapidly here, increasing their weight. In Switzerland, Austria, and here in the Tien Shan, the Caucasus, and Altai, herds of sheep, cows, and goats graze from early spring to late autumn in mountain meadows above the line of coniferous forests.

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In the boreal forests, mainly different types of firs, spruces and pines grow. Where there is less moisture, and primarily in Siberia, larches predominate. The species diversity in the boreal forests is low, and although mixed forest grows in some places, much more often huge spaces are occupied by trees of the same species. This uniformity is a hallmark of boreal forests.

Coniferous trees grow much denser than broadleaf trees. For 100 m 2, for example, it can grow up to 14-15 spruces. Because of such tightness, the shadow there is very thick - there is practically no light left for other plants. Nothing usually grows in the litter of a spruce forest. And in the pine forests, the shade is not so thick, and many herbs grow there.

Hardy deciduous trees are also found in boreal forests. They grow around lakes and meadows. But conifers, in the end, drown out and displace them.

Altitudinal zonality

When climbing a high mountain, with each kilometer, the air temperature will drop by approximately 6 ° C. Therefore, even at the equator, where the climate is hot, it is cold in the mountains. And on the slopes of the mountains, several natural belts can be distinguished. The tops of the mountains are covered with snow and ice - it is too cold for plants there. Below, where it is warmer and more humid, grasses and shrubs begin to appear. Coniferous forests usually grow high on the slopes, and below they are replaced by broad-leaved ones. Where persistent cloud cover creates a cold and humid climate, cloudy mountain forests grow.

Altitude zonality in the mountains is found not only in the tropics. In the Rocky Mountains of North America, coniferous forests extend much further south than in neighboring valleys.

coastal forests

In New Zealand and the northwestern United States, on the slopes of the coastal mountains, climatic conditions have given rise to variable-moist (or rain) forests of the temperate zone. Warm, moist winds from the sea bring heavy rains, stimulating lush vegetation. The rainforests of New Zealand are famous for their abundance of tree ferns. The vegetation of the American rainforest is more typical of temperate climates, and the trunks of the trees are covered with a layer of moss.

A narrow strip of mangrove swamps stretches along the tropical and subtropical coasts. Mangrove trees can grow in salt water, and some species grow in the tide zone. Thanks to respiratory and stilted roots, these trees survive in swamp conditions. Away from the seashore, where the water of the swamps is no longer so salty, there are other trees.

3. ANGIOSEED PLANTS

In flowering plants or angiosperms, trees are much more diverse than in conifers. Distinguish between tall and multi-stemmed trees. The former have a well-defined main trunk, which branches at a certain height, forming a crown. The main trunk lives for tens (and in some cases hundreds and thousands) of years, without stopping growth. In multi-stemmed trees, after some time, the growth of the main shoot slows down, and additional shoots develop from dormant buds at the base of the trunk. Similar trees are typical for tropical and subtropical regions. Trees can vary greatly in trunk and crown shape, and in the location and function of above-ground adventitious roots. In Brazil, Australia and Africa, there are so-called bottle trees, in which the trunk, carrying a large supply of moisture, really resembles a bottle in shape. Such trees are typical for savannahs and tropical regions with long dry summers. The savannas of Africa and Australia are characterized by umbellate trees. The shape of the crown resembling an open umbrella is formed in them under the influence of a large amount of light in combination with a lack of moisture. In some trees, the crown consists of several large leaves, forming a rosette at the top of an unbranched stem. This shape is typical for palm trees. Palm-like plants with a bare, non-branching trunk are common in the tropical regions of the Earth, and in the temperate zone all trees, one way or another, branch. Under the influence of severe climatic conditions at the extreme northern and southern borders of the range, as well as high in the mountains, trees take the form of a stlantsa. In such trees, the trunk with a crown droops and grows in a horizontal plane, while only young shoots rise vertically. The life expectancy of stlanets can exceed that of ordinary upright trees of the same species.

Among the trees there are those in which the trunk wraps around other trees. This is how the shape of a tree-like vine is formed. Such plants are typical of tropical forests, less often they are found in the subtropics.

Trees growing in the tropics are characterized by the presence of aboveground roots - props, stilted and plank roots, which give the trees a very bizarre appearance. So, in representatives of the tropical genus ficus, a large number of prop roots, adventitious roots on the side branches are formed, which, having reached the ground, take root and form a kind of "trunks". This form is called banyan.

Trees are the predominant life form in the humid tropical regions of the planet. It is there, in the most favorable growth conditions, that the trees reach their maximum size. In the temperate zone, there are already many more herbaceous plants than woody ones. In those places where the climate is warm, but dry, or, conversely, humid, but cold, woody forms pass into a shorter shrub form.

4. CONIFERS - A STRATEGY FOR SURVIVAL

Coniferous trees have to endure very harsh winters. The temperature there is below 0°C, and often drops below -40°C. Winters bring severe drought as groundwater freezes completely. Snow lies for a very long time, only a thin layer of soil thaws in summer, and there is little water available to plants.

Coniferous trees are evergreen, so even in winter their needles continue to produce nutrients. The surface area of ​​a single needle (their “leaf”) is very small and is covered with a layer of wax. This delays evaporation and helps conserve water. In addition, a substance is produced in the needles that prevents them from freezing and dying from frost.

In the coldest arid areas, larches shed their needles to keep water loss to a minimum.

The roots of conifers are shallow and highly branched to collect moisture from a larger area. And such a root system allows you to absorb nutrients even in early spring, when the soil thaws only a few centimeters from the surface.

The high density of trees helps them retain heat. The air, captured by the needles and branches, forms a kind of insulating layer around each tree. And the conical shape of the trees does not allow snow to linger on the branches, and they do not break under its weight.

In winter, conifers make the most of the sunlight. Their shape is such that the sun's rays reach every tree. The heat reflected by the snow lingers between the trees.

5. NEEDLE AND SOIL

Dying needles fall to the ground all year round. Over time, they accumulate in a thick layer on the surface. In cold climates, they rot very slowly. In addition, the acids contained in the needles repel decomposers (bacteria and other organisms that decompose organic matter).

Dead needles contain few nutrients. Due to its acidity, earthworms and insects do not mix the needles with the soil. As a result, infertile acidic soils are formed that are not suitable for other plants. By creating such soils, conifers increase the territory of their own distribution.

Coniferous trees could not exist so successfully in such conditions without "helpers". They thrive through symbiosis with fungal mycelium. Mushroom pickers supply the roots of trees with the necessary minerals, receiving nutrients in return.

The soils of coniferous forests are infertile. The shallow root system allows the trees to absorb water from the spring-thawed soil.

6 . HOW TREES GROW

Like all living things, trees need food to grow. How does the tree get it? From the soil, the plant receives water and mineral salts. From the air - carbon dioxide, and the green leaves of the tree process solar energy into starch, sugar and cellulose. This releases oxygen into the atmosphere. That is, a chemical process occurs that ensures the growth and development of the tree.

Between the wood and the bark of the tree there is a thin layer of cells - the cambium. New cells are created in this layer. Those that arise on the inside of the cambium form wood, on the outside - bark. The diameter of the tree increases constantly, but this does not happen with the bark. It bursts, dies and falls off. The tree grows tall and wide. At the tip of each branch there are cells that divide. They form new leaves, and the branches lengthen.

Over time, the growth of branches slows down. The new cells become hard, scaly-like, gradually becoming a bud. These buds are easy to spot on a tree in winter. In the spring, the buds open or fall off, and the shoot begins to grow again.

For a plant to be healthy, it turns out that good nutrition and lighting are not enough for it. The relationships between plants in a community are very important. Trees grow much better if mushrooms settle on their roots: boletus - in a birch forest, white - in an oak forest, and butterflies - in a spruce forest. This mutually beneficial partnership is called symbiosis.

The leaves and roots of some trees, such as bird cherry, spruce, pine, oak, release substances that inhibit the growth of their neighbors. Therefore, pine forests and oak forests are so transparent, the undergrowth is not at all dense.

7 . WHY TREES RINGS

If you look at a cross section of a tree trunk or branch, you can easily see the so-called growth rings. Why are they formed? The fact is that the trunk and branches consist mainly of wood - a mixture of cellulose and lignin, that is, organic substances of a complex structure from the class of hydrocarbons, the main property of which is to be solid, to form, as it were, the skeleton of a plant. But the trunks and branches must grow every year. Why? But because the leaves of trees, even evergreen ones, are not at all eternal and are replaced with new ones over time. There are also new
twigs with new leaves, which increase the already heavy load on the trunk and branches. So they need to be strengthened. So a new ring of wood is growing.

How does this happen? On the outer surface of wood in the form of a cylinder (in the shape of a trunk), all trees and shrubs have a cambium - a thin layer of living and rapidly dividing cells. In spring, these cells divide quickly, the tissue grows, but gradually division and growth slow down, and the cells become smaller. By the end of summer, they already divide quite “reluctantly” and form very small cells. What does all this lead to?

Firstly, to the fact that another layer is deposited on top of the previous layer of wood, and secondly, this cylinder turns out to be heterogeneous: its inner part is formed by large cells, and the outer one by small ones. The next spring, everything repeats again, and as a result, a layer with large cells begins to be deposited on top of the wood from small cells. The boundary between two such layers is clearly visible on the cut. So, one such ring is deposited per year, which means that by counting all the rings, you can determine how old a branch or trunk is. It was these calculations that made it possible to establish how many years some trees live: oak - 2000 years, sequoia (mammoth tree) - 5000 years, some cycads even up to 10,000 years! However, the lifespan of most trees is much shorter. Bad weather, storms, fires, environmental disruption greatly reduce their age, and the age of 500 years for our lindens and oaks is quite respectable. For birches, it is the limit. Birches and aspens at 100 years old are already old plants, and poplars rarely live to such an age. The reason for the unequal durability of trees lies in the different degrees of strength of their wood and its tendency to rot.

The fact is that as new layers grow, that is, new rings, wood, the old ones are gradually buried in the depths of the trunk and lose their viability. Living protoplasm leaves them, and only lignified (lignin) cell walls remain. If air and water enter the trunk, the wood may begin to rot. And getting access to air and water is quite simple if, for example, a branch or twig is broken off a tree, or the bark is damaged. This is how the hollow begins to form. True, it happens that the trunk inside is completely rotten, and the tree, nevertheless, remains alive. However, then the trunk becomes clumsy, the branches dry quickly, and the crown of the tree also dries.

8 . WHAT IS KORA

The trunk of any tree is formed by a layer of living cells - the cambium. Cambium (from Late Latin " cambium "- exchange, change) - a single-row layer of plant tissue cells, in which later, in the process of dividing inside, wood (secondary xylem) is formed, and in the process of dividing outward - bast (secondary phloem). Phloem (from the Greek. " phloios "- bark) - the conductive tissue of plants, formed from the cambium and used to transport photosynthesis products from leaves to other organs (roots, fruits, etc.). The secondary phloem is called the phloem. Xylem (from the Greek. " xylon "- felled tree) - the water-conducting tissue of plants that forms wood, the different growth rate of which forms growth rings.

In the process of cell division, wood is deposited inside the trunk, and bast is deposited outside. Bast is the inner, living part of the bark of any tree or shrub. Alive means filled with protoplasm and juices that move from top to bottom, from leaves to roots. And in wood along its outer edge, where the youngest tree rings are deposited, water moves from bottom to top, from roots to leaves.

In the bast there are layers of living cells, similar to the cambium, that is, capable of actively dividing and producing other cells. They are needed just in order to create a protective layer outside for the bast cells. Otherwise, the barrel would be damaged from any touch. The plants protected themselves with armor, not of metal, but of bark. The wood of the trunk is composed of cellulose and lignin, and the outer crust is built from a substance called suberin (from the word "suber" - "cork").

Cork (phellema ) - the outer part of the secondary integumentary tissue of plants. It develops on trunks, branches, roots, sometimes on kidney scales, fruits (pears), rhizomes, tubers (potatoes). Cork protects plant organs from excessive evaporation and the penetration of microorganisms into them.

Well, what kind of material - cork - is well known to everyone. Corks plug the necks of bottles. The best corks are made from the bark of the cork oak, which is specially bred for this purpose in many Mediterranean countries.

So, in the outer layers of the bast there are layers of living, dividing cells that form a cork protective tissue. But these layers do not form either a continuous ring or a cylinder, but are located in separate foci and work intermittently, since, pushed aside by the wood growing from the inside and the inner layers of the bast, they gradually lose their viability and stop working. From inside the bast layer, they are replaced by other cells.

At the birch, the outer crust, the familiar birch bark to all of us, on which our distant ancestors wrote letters, instead of suberin, is impregnated with a similar in composition, but still somewhat different substance - betulin, which colors it white, not brown.

Now, perhaps, it is clear why the bark on old trees is so cracked. Because both wood and bast continue to grow (thanks to the cambium), and the dead, outer, part of the bark

What thickness of the bark was originally, when the tree was of a smaller diameter, it remains so, and its inner layers seem to be bursting. Imagine what will happen, for example, to a balloon if it is inflated to infinity? Will burst. So the outer layer, in the end, bursts here and there.

So, the outer layer of the bark (crust) consists of dead tissue of the bast and the cork layer.

In central Russia, the bark of all trees, or rather the outer dead layer, is very thick. It protects the tree well from frost. But do trees need such protection in countries with mild winters? Wouldn't it be better to do without the outer crust altogether? And, imagine, cost. For example, eucalyptus. On the Black Sea coast of the Caucasus in autumn (September-October, which corresponds to spring in the southern hemisphere), one can see huge, rolled-up tatters of the old crust hanging from the trunks and branches of eucalyptus trees. This tree apparently has a layer of cells separating the bast from the crust, as continuous as the cambium. However, here, too, the outer crust cracks longitudinally under pressure from the inside, since the bottom of the eucalyptus trunks is thicker than the top, and therefore the cracks go from bottom to top. Outside, on the trunk of the eucalyptus, there is again a smooth bark without cracks, formed mainly by a bast with a thin but strong layer of protective cork tissue.

Every year, in this way, some other trees change their bark, for example, the strawberry tree. The old and new bark of this lovely tree are very different from each other: one is red, the other is greenish-yellow. Yes, and in plane trees (plane trees), each layer of the bark lives a little more than a year. The bark of this tree does not change immediately, but gradually, in small areas.

9 . HOW TO DETERMINE THE AGE OF A TREE

No problem if the tree is cut down. It is enough just to count the annual rings on the stump. What if it hasn't been cut yet? In this case, measure the circumference of the trunk at a height of 1.5 m from the ground. The result will be approximate; its accuracy depends on several factors of the species and features of the tree. IN; In general, for fast-growing trees (poplar, linden, chestnut), you can count every 20 cm of circumference in 10 years. For trees with an average growth rate (sycamore). 15 cm - in 10 years: For slow-growing trees (oak, beech, hornbeam) - 10 cm in 10 years. So an oak with a trunk circumference of 1 m can be 100 years old.

10. THE FATE OF THE DEAD TREE

An old or diseased tree quickly collapses. Very soon it will be attacked by microscopic fungi. Woodlice and slugs settle in wood; spiders and centipedes hunt in search of prey.

After one year, the bark begins to fall off in some places. The reason for this is parasitic fungi that live on its trunk, and insects that sharpen its wood and. lay their eggs in it

After 3-5 years, the bark disappears completely. In the depressions formed, various phrases begin to grow (for example, sour), in some places ivy appears. Gradually bark beetles, slugs and other inhabitants of the tree leave it. The wood becomes rotten and finally crumbles.

11 . WHY YOU NEED LEAF FALL

How beautiful the forest is at the end of September! Against the background of a still green hazel, the leaves of a young birch are already turning yellow. And the maple and oak are elegant in green and red decoration. Why do leaves turn different colors in autumn? Let's remember that they owe their green color to the presence of a green pigment in them - chlorophyll. But there are other substances in the leaves. For example, the substance xanthoyl is composed of carbon, hydrogen and oxygen and gives the leaves their yellow color. Carotenoids are also present in the leaf. (There is especially a lot of carotene in carrots.) Bright red, crimson hues give anticyanite pigments to maple and oak leaves.

In summer, these pigments are not visible, we see only green chlorophyll. With the onset of cold weather, the nutrients collected in the leaves of trees enter the branches and trunk. Since the production of nutrients stops in winter, chlorophyll decomposes. With its disappearance, other pigments that were constantly present in the leaf become visible. And we enjoy the variety of tree colors.

By autumn, a thin layer of easily detachable cells forms at the base of each leaf. A gust of wind rips off the leaves. A scar remains on the shoot, indicating the former location of the leaf. Most evergreen trees do not shed their entire cover when cold weather approaches. This happens gradually throughout the year, so they always stay green.

Autumn leaf fall is very important in the life of the forest. Fallen leaves serve as a good fertilizer, protect the roots from freezing.

12. WHAT SEEDS TRAVEL ON WATER AND AIR

In the alpine steppes, deserts, savannas, where there are strong winds, the seeds scatter over long distances, especially if they are small or light and flat.

Seeds with wings were formed from plants that live in open places. Anemone seeds are completely covered with hairs. In willow, poplar, small seeds are equipped with a tuft of fine hairs. Yes, and poplar fluff is well known to us. The fruit of hazel, birch, alder and hornbeam is a small nut with two wings. One wing each - in the fruits of maple and ash. That's why they spin when they fall.

13 . IMPACT OF CLIMATE ON TREES

Climate is one of the most significant factors that determine the nature of forest vegetation and the evolution of tree species over geological time. The current distribution of most of these species on the globe is due to relatively recent climatic changes. The trees, in turn, have enabled modern science to reconstruct the climatic conditions of the prehistoric period, down to the direction of the prevailing winds that carried their seeds.

The ancestors of all our trees were tropical plants. In the tropics, seasonal temperature changes are usually small; only the amount of precipitation varies from one season to another. Most tropical trees are evergreens and can grow either continuously or in periods when sufficient moisture is available. Special areas in the tropics are mountainous areas, such as the equatorial Andes or the mountains of Kenya and Kilimanjaro in Africa, where the temperature decreases with height and stunted, bizarre alpine plants are characteristic of the upper parts of the slopes and mountain meadows.

Temperate trees are well adapted to the changing seasons. They are called winter-hardy, as they are able to withstand long periods of frost and sharp temperature fluctuations.

14. HOW TREES PROTECT FROM Frost

If clouds or treetops keep a layer of warm air close to the ground, heat cannot escape into the atmosphere, and there is little chance of frost (A). On a cloudless night (B), the earth freely loses heat. and soil temperature drops below air temperature (B). The soil takes heat from the surface layer of air, and as a result, radiation frost occurs.

The cold air accumulating in a thin layer at the level of the soil flows down the slopes, gathering in the lowlands and forming "pockets" of cold. The level to which the depressions are filled with cold air can be seen from the lower branches of the trees.

15. WHAT ARE ENDEMICS

Plowing up new lands, building cities, dams on rivers, for many centuries people carelessly and thoughtlessly took everything they wanted from nature. And in the second half XX V. it turned out that some once common plants and animals, especially useful or very beautiful, began to disappear. There are no more thickets of water chestnut or chilim on the lakes, it is almost impossible to find ginseng root in the taiga, lily of the valley has completely disappeared from the forests near Moscow, yellow roses of bathing suits in coastal thickets and beautiful water lilies on forest ponds have become rare. Now these are rare, or endemic, plants.

Long-lived plants can also be called endemic. The landscape surrounding them has changed, new plant species have appeared and disappeared on the planet, and they all meet and see off for centuries. Only a small grove of Lebanese cedars remained on the planet. Centuries-old American sequoias are given their own names. Only in the Seychelles and nowhere else does the Seychelles palm grow. Among the endemics there are also predatory plants. There are still plants on the planet that are endemic due to their geographical location. Granite Seychelles can be called one of the wonders of the world. They have lived in isolation for a very long time. It is believed that this is a fragment of the ancient single continent Gondwana, which then “broke up”, forming all modern continents. There are over 70 endemic plant species and genera in the Seychelles.

16. WHAT ARE PHYTONCIDES

In spring, the bird cherry shrub or tree is strewn with snow-white tassels of flowers. And even if you didn’t notice flowering plants in the forest, passed them by, you will still feel a strong, intoxicating smell. Bird cherry smells very pleasant, but we do not recommend keeping a large bouquet of these beautiful, fragrant branches at home. The smell of bird cherry can cause a severe headache. Why? The fact is that bird cherry emits strong phytoncides containing poisonous hydrocyanic acid. Phytoncides are volatile substances secreted by a plant. They kill microorganisms that are normally found in the air. Therefore, it is so easy to breathe in the forest.

Bird cherry phytoncides are so strong that they kill flies, mosquitoes, horseflies, mold fungi if they are placed in a jar with flowers and crushed bird cherry leaves. The Colorado potato beetle does not like calendula (or marigolds) very much - the worst enemy of potatoes.

Phytoncides contain fir, pine, spruce, jasmine, black currant, mint, lily of the valley, juniper, nettle, lemon, orange, dill, parsley, radish, pepper.

Pine forest emits 5 kg of phytoncides from 1 ha per day, larch - about 2 kg, juniper - up to 30 kg.

Many plants produce phytoncides. We usually smell their scent, strong or weak. Phytoncides of fir, oak, poplar leaves kill diphtheria bacilli. Pine phytoncides have a detrimental effect on tuberculosis pathogens.

Phytoncides are also secreted by microorganisms and lower fungi. They are called antibiotics. Many powerful medicines are prepared on their basis.

Wood is the main material for making paper.

Wood is the main material for paper production. In nature, paper is also used, or, more precisely, papier-mâché.

Just as bees build their hexagonal combs from wax, so wasps build their combs from paper. Hexagonal design saves space (more than 100 combs can be placed in the palm of your hand for larvae or honey storage). Wasps scrape dry wood with their jaws, significantly increase its volume with saliva and stick the fibrous substance in layers. This is how paper honeycombs are built. Field wasps build their nests from one or more free-hanging combs. Some types of wasps living under the roofs of houses wrap their combs in bell-shaped paper formations. They are impregnated with a special substance and therefore waterproof. When it rains, water flows off them.

Elongated tree cage

Paper multifunctional systems. Large colony-forming wasps build nests as a multi-component system that performs different functions. Wasps use a material that resembles paper, but they use hollow spaces filled with air. All this structure also acts as a thermal insulator. Thus, with the help of one material, nature achieves different goals. This paper nest on the ledge is almost the size of a soccer ball.

Who wants to know what cellulose feels like, he should pick up a cotton

Wand. Its head is made up of almost pure cellulose fibers.

22. PRE-HARVESTING AND DEVELOPMENT

Development means change, growth. So, for example, a flower appears, already born in a kidney. The principle of pre-harvest is familiar and technical.

Bud.In the bud, the elements of the flower are rolled up in a narrow space. Due to the increase in pressure and growth processes, the petals of the bud shell diverge, a flower is shown, which then blooms and often becomes so large that its size could not be guessed in advance. It is sometimes difficult to imagine how a flower could fit in a small bud. The principle of nature is this: preliminary placement in the narrowest space is combined with an increase in size as the flower opens. The same rule applies to leaves. Sometimes both flowers and leaves are born in one bud, as, for example, in a chestnut tree.

Interchangeable boards.Increasingly, technology uses the principle of pre-preparation, borrowed from nature. Instruments are often designed as follows: entire groups of components are prepared in advance, which are then placed in intermediate warehouses awaiting assembly. So, for example, plug-in boards with ready-made circuits for computers and TVs are produced. When an element fails, the old board is removed and a new one is inserted.

23. PEOPLE VS TREES

Farmers have a very ambivalent attitude towards trees. Often they think that on the lands occupied by trees it would be possible to grow crops and breed cows and sheep.

Trees have served man for a long time. After all, wood is an excellent building material. From it you can make strong supports for the bridge, and elegant carved legs of tables and chairs. Man has discovered other ways of using wood, and one of the most important is the manufacture of paper. Newspapers and magazines, notebooks and envelopes - much of what we use today is made from wood.

In addition, the forest is still an important source of fuel. Billions of people continue to use firewood to heat their homes or cook meals.

Today, only 50% of the forests that once covered the earth have survived. In their place are now fields and cities.

About 10,000 years ago, the zone of natural distribution of forests - taiga, broad-leaved and humid tropical - occupied vast expanses of land.

With the onset of the Industrial Revolution, deforestation intensified. Today, the worst enemy of the forest is a manual gas or electric saw. With the spread of man around the globe, forests began to recede. And the first period of their extermination is associated with the development of agriculture that began about 6000 years ago. The best lands were cleared of the forest, and in the place where the trees grew, people raised cattle and sowed grain.

The second period of deforestation began about 2000 years ago. Metalworking has spread, requiring huge amounts of charcoal. Other branches of handicraft production also needed wood. Thus, many oak forests in England were destroyed when wooden ships were being built for the Royal Navy.

In Europe back to top XIX centuries, the areas of deciduous forests have significantly decreased. Soon a similar fate befell the forests of North America and Australia. In the last 80 years alone, about half of the forests have been destroyed.

Forests were cut down with stone tools and burned. Grain crops were sown in the vacated areas. This system of farming was called slash-and-burn. As metal tools, ploughs, and the use of draft animals proliferated, peasants began to clear even larger tracts of forest from the forest.

24. HOW FOREST DEATH HAPPENS

Deforestation is now causing alarm around the world. Every eight minutes, 259 hectares of rainforest are cut down. Forest use is now tightly controlled in many countries, but in many cases irreparable damage has already been done. Logging, oil and other mining, agriculture, city and road construction, and many other human activities are a real disaster for the rainforest.

In the subtropics and savannahs, prolonged droughts and human need for fuel threaten the few remaining forests with complete destruction. In Southeast Asia, mangrove forests are savagely cut down to make chopsticks.

The consequences of deforestation are most pronounced in mountainous tropical regions. Downpours wash away the soil left without the protection of trees from the mountain slopes, leaving bare sheer cliffs and deep ravines. Water carries soil into rivers. And there it clogs the channel, clogs irrigation canals and causes crops to suffocate under a layer of silt.

The pace of deforestation urgently requires the introduction of control over the use of the forest. The worst is in the tropics. Brazil's tropical rainforest is being cut down at a catastrophic rate. Environmentalists are worried about the fate of many of the world's forests.

In some countries, deforestation is now banned and rainforests are protected by law. An important role in this belongs to environmentalists, who incline public opinion in favor of protecting the forest.

However, it is much easier to prevent destruction than to restore a lost forest. In many areas, soil erosion has gone so far that giant trees can no longer grow on such soils. Even under favorable conditions, forest restoration is a long process. It can take up to 600 years before the tropical rainforest returns to its original state.

In temperate zones, vast areas of cut down deciduous forests are planted with fast-growing coniferous trees. Although they are a renewable source of wood, the choice is far from the best. Conifers increase soil acidity and can interfere with soil drainage. If they are alien to the region, they will not be useful.

25. HOW THE FOREST RESTORES

The first to invade the fields were wild grasses, weeds we all know. Under their cover, the seeds of trees and shrubs took root. Creeping plants - wild rose, blackberry, ivy - covered the whole earth. And after 25 years, young broad-leaved trees were already growing there. The seasonal life cycle of a tree. 1) Spring: leaves grow. 2) Summer: dense foliage on trees. 3) Throughout their history, people have cut down huge arrays of trees for crops and pastures. When the land ceased to be cultivated, natural vegetation was restored on them. Scientists have been able to trace how different plant species gradually conquered the former fields until a certain plant community was established there. Autumn: Leaves wither and fall off. 4) Winter: the trees are bare.

Fallen leaves on the forest floor increase the nutrient content of the soil. They are then taken up by tree roots.

Dropping leaves is a great way to store nutrients for next year. The low temperature in winter slows down the rotting process, and nutrients are stored until the start of the growing season (until spring).

Earthworms and insects mix rotted leaves into the soil. The nutrients that enter the soil from the humus are absorbed by the roots of the trees, and over time, the soil of deciduous forests becomes very fertile.

Different trees need a different amount of light, so the shadows of their crowns are also different. Beech tries to take most of the world. For every square meter of land under a beech, there are almost eight square meters of crown leaves. As a result, the beech casts a very dense shadow, and very few plants can survive in it. There is practically no undergrowth in the beech forests.

Because of the shade cast by the trees, many plants bloom in early spring. Scilla, like other primroses, manages to complete the annual cycle of development: blossom, bloom and give seeds before the crowns of trees close.

In autumn, the ground in the forest is covered with a carpet of fallen leaves. Their layer compacts and rots, turning into humus and soil.

As tree roots penetrate deeper into the parent rock, destroying it, fertile, well-mixed soil is formed in deciduous forests. Many species of trees grow in such forests: from oak to horse chestnut and sycamore.

26 . TREES IN TALES AND MYTHS

Trees existed on our planet long before the appearance of man. Many of them still live much longer than humans. The oldest giant trees and centenarians are now more than 2000 years old. But in ancient times, people treated trees with much more respect than they do today.

In ancient times, people considered the forest to be a mysterious and scary place. Their imagination inhabited the dark forest thickets with bloodthirsty monsters, evil trolls and other evil spirits. In many myths, legends and traditions, the most strange and unexpected things happen in the forests. But the forest dwellers, on the contrary, treated trees and animals as if they were their own kind, endowing them with a soul.

The Green Man is the pagan god of spring,

To which the celebration of the first of May was dedicated.

In ancient India, peasants often deified a tree. While everything was safe in the village, the tree was worshiped and brought gifts to it. But as soon as luck turned away, they forgot about the tree, leaving it to the mercy of fate.

The tribes of ancient Europe had many beliefs associated with trees. Often trees were planted in sacred rings, alleys or groves, where only priests and priestesses could enter. In North America, the Indians of many tribes tried not to cut living trees so as not to hurt them.

Carved ornament from a church in Norway

Forests have always inspired artists and writers. There is hardly anyone who has not heard the fairy tale about Little Red Riding Hood, which the Gray Wolf wanted to eat. The English writer John Tolkien, in his fairy tale trilogy The Lord of the Rings, turned giant trees into Ents who could walk. We need forests. Nothing can replace them. After all, this is a home for the rarest plants and animals of our planet.

Tolkien's imagination made the trees

Similar to people, endowing them with different characters.

27. NEW YEAR WITH A FIR BOUQUET

For many years, the “greens” have been calling for refusing to buy a live Christmas tree so as not to destroy a living tree for the sake of a moment of joy. And this does not mean at all that on New Year's Eve you should be left without the magical smell of the forest!

Imagine that in your apartment you have correctly cut down (one from the tree and not from its top) or correctly bought (the merchant had an invoice from the forestry enterprise) spruce branches. How to make them even more magical?

An example of a “correct” bouquet is the traditional asymmetrical triangle. To the right of the vase, a large spruce branch is directed upwards, the rest of the branches from its center lean down to the left. From above, the bouquet looks like an elongated oval, from the side - like a high chair with a backrest on the right.

The shape of the bouquet is "seated person". And in the place of "connecting the back to the seat" it is necessary to place an accent - a ball or a candle. For bouquets in a vase, the ratio of the height of the vase to the bouquet should be equal to the classic Japanese proportion - 3:5.

To keep the bouquet in the basket, fill the bag with wet sand, tie it tightly, turn it over and place it tightly in the basket. The branches are stuck into the bag, but their location cannot be changed, the sand will pour out through empty holes, the bouquet on the wall can also be extended. Put a potato on a cut of branches, disguising it with a toy or a bow. And you can first hold the branches for two hours in water, and then wrap the ends with tape. Needles do not usually fall off for a long time if the branches are not near the battery and have access to moisture.

The colors for New Year's compositions are red, white, raspberry, but blue against the background of pine needles is not advantageous. A bouquet looks beautiful, in the decoration of which only one color is involved. For example, silver white: silver tinsel, white packing tape, silver bells. More than 4 colors should not be used at all.

An unusual decoration is obtained on the basis of a hoop. Two big branches
crossed at the bottom, let them go from bottom to top. In order to avoid resemblance to a mourning wreath, in no case should they be tied to the hoop with a red ribbon only with something colorless! The rest of the hoop is wrapped with tinsel, two balls are hung from above at different heights on packing tapes.

One small branch can magically change the apartment, if you wind it to the edge of the wicker stand, starting from the bottom, slightly to the left of the middle, wrap the rest of the edge with tinsel, and strengthen the bow on top.

And you can still prepare material for an unusual Christmas tree in the summer - from cones. True, you will need a large supply of spruce or pine cones. Think about it in the summer! The base of this unusual Christmas tree is a pear-shaped cover sewn from fabric and stuffed with cotton wool. To ensure stability, it is strengthened on a fairly massive stand. With the help of threads and glue, cones are attached to the base. And then they decorate the Christmas tree with garlands of light bulbs, small toys - as fantasy tells. Try to do it - and the children have an interesting lesson, and one less cut down Christmas tree.