What happens to trees and shrubs in late autumn and winter. Does a tree grow in winter: features of plant development Where do cracks in the bark of trees come from

Such a statement to an amateur gardener may seem strange. Indeed, in the literature we read the following: "The roots continue their vital activity if the temperature in the surface root layer of the soil is positive." Everything is correct, and gardeners of small-sized garden plots, and these are inquisitive, persistent people, often empirically confirm the above conclusion. So, in our gardening during autumn tillage, we, in addition to organic and mineral fertilizers(potassium, phosphorus) we also introduce nitrogen. Horrible! - the “erudite” reader will exclaim, - how is this possible? After all, nitrogen fertilizers are applied to the soil only in spring. Moreover, in autumn we also wood ash scatter under the trees. It would seem that this makes no sense, because in winter the roots "sleep" and the tree is in biological rest.
However, its roots continue to live through the winter months. Even in the last century, it was noticed that the roots and shoots of trees have two phases of intensive growth. The aerial part grows and develops in warm time year, but the roots behave differently, such is their nature - they continue to grow in winter. In an apple tree, for example, they can grow even in January, if the temperature around them does not fall below -1 ... -2 ° C.
Much depends on the reserves of moisture and nutrients in the soil, the soil solution and the water that the roots absorb. With the help of competent agricultural technology, the gardener can purposefully and timely form the necessary, large mass of tree roots and lengthen the period of their growth. Experienced it was found that the roots that appeared in autumn and winter are more stable and durable than spring ones. Few amateur gardeners know about this, but it is true. Research scientists have shown that root system plants absorbs from the ground nutrients not only in autumn, but also in winter, if the soil is not too frozen from above. Yes, it cannot freeze much if it is covered with a thick layer of snow (this the best cover above-ground parts of plants from frost). 20-30 cm of snow cover is enough to protect the roots from freezing, and if we bring this snowy mound to a height of 120-150 cm, then even in the most severe frost the temperature under it will not fall below -6 ... -10 ° C , In the soil itself, it retains positive indicators for a long time. This allows the roots to continue to accumulate nutrients in preparation for spring growth.
Thus, plants convert mineral nitrogen into organic nitrogen, accumulating it in the root system. At good care Behind a tree, the nitrogen content can double from early October to January! Whereas in poorly fertilized areas it can grow only by 10%. In this regard, it is very useful to add saltpeter or ammonium sulfate to the soil in autumn and winter. From all that has been said, we make an important practical conclusion: do not be afraid to feed trees and shrubs in autumn nitrogen fertilizers. These fertilizers will not harm the soils of the Non-Black Earth Region, which are not distinguished by high fertility. However, such top dressing is useful only for those plants that bear fruit well this season.
important in the protection of plants from low temperatures have their adaptability. Yes, in winter period the reserves of substances that protect the plant organism from the cold increase: sugars, proteins and lipids, which are essentially cryoprotectants or antifreezes. They allow the plant to avoid or reduce the consequences of stressful situations.
However, under conditions of extremely low temperatures, many plants die due to the fact that their intracellular fluid freezes, and the cells are destroyed. At frost-resistant species In plants, this usually does not happen, because they are protected from the inside by intracellular substances of antifreeze or cryoprotective action.
I. Krivega
Newspaper "GARDENER" №6, 2010

With the onset of winter, the trees go into a dormant state. The metabolism inside the trunk slows down, the visible growth of trees stops. But life processes do not stop completely. During the period of long winter dormancy, mutual transformations of substances occur, however, with much less intensity than in summer (Journal "Chemistry and Life", "Plants in Winter", V.I. Artamonov, February 1979).

Growth is underway, although outwardly it is practically not manifested. In cold weather, the so-called educational tissue actively develops, from which new cells and tissues of the tree subsequently arise. In hardwoods, leaf primordia are laid in winter. Without such processes, the transition of plants to active life with the advent of spring would be impossible. The winter dormancy phase is an indispensable condition for the normal growth of trees during the growing season.

The ability of trees to sink into a dormant state has evolved over a long period of evolution and has become the most important mechanism for adapting to adverse and harsh external conditions. Similar mechanisms are involved in other difficult periods of tree life, including summer. For example, in a severe drought, plants can shed their leaves and almost completely stop their growth.

Features of winter dormancy in trees

The signal for the transition to a special winter state for most trees is a reduction in the length of daylight hours. Leaves and buds are responsible for the perception of such changes. When the day is noticeably shortened, in plants there is a change in the ratio between substances that stimulate the processes of metabolism and growth. The tree is gradually preparing to slow down all life processes.

In a state of forced dormancy, the trees remain until the end of the winter period, gradually preparing for full awakening. If at the end of February a birch branch is cut in the forest and placed in water in a warm room, after a while the buds will swell, preparing to sprout. But if a similar procedure is done at the beginning of winter, the birch will not bloom for a very long time, because it is already completely ready for rest.

The duration of the winter dormancy period is different for different types trees and shrubs. In lilacs, this period is very short and often ends by November. In poplar or birch, the phase of deep dormancy lasts much longer, until January. Maple, linden, pine and spruce are able to be in a state of deep forced dormancy for four to six months. After wintering, the trees slowly but steadily begin to restore life processes, renewing their growth.

Some people are interested in the question of whether trees grow in winter? The answer is simple and difficult. From school curriculum It is well known that trees winter time are at rest, but this does not mean that it lasts the entire winter period. All living organisms, including plants, experience periodicity in development. Trees are no exception, they also have certain periods: two main ones (vegetation, dormancy) and two transitional ones.

Vegetation and dormancy

The state of vegetation does not need to be explained. It is during this period, which is the longest, that the laying and development of flower and leaf buds takes place, from which leaves, ovaries, flowers appear, fruits grow and ripen. There is a significant increase in the root system. By the time the leaves are formed, it is very important that many small suction roots appear.

In the period of winter dormancy, the trees seem lifeless, but it is worth noting that this is an external manifestation. Their active functioning continues, however, it is not as intense as in summer, a certain amount enters the plant. useful substances and water. So is it true that they also grow?

When there is a state of rest

It is generally accepted that the state of dormancy occurs in winter. This is not true. It starts very early. For this, there is a certain signal that nature gives to trees - a decrease in the length of daylight hours. At this time, the weather is warm, sunny days, but the trees begin to fall into a state of rest. It is at this time that the preparatory period begins, preceding the state of rest. It is characterized by the beginning of a slowdown in metabolism, yellowing and subsequent shedding of foliage.

Since December, an increase in daylight hours begins, and the vital activity of trees is activated. The preparatory period preceding the growing season begins. That is, the processes of formation begin. All this gives the full right to give an affirmative answer to the question of whether trees grow in winter.

It has been noticed that a tree growing near a lamppost or near a house where the light is on in the evenings does not shed its foliage for a long time. This is a direct confirmation of the dependence of the state of rest on the length of daylight hours.

What happens at rest

Do trees grow in winter? We can definitely say that in the initial period of dormancy, the growth of trees stops, as the metabolism and visible growth are inhibited. But this does not mean that life activity stops. Processes are ongoing, and they are important enough for growth. The starch accumulated during the growing season is converted into sugar, which is consumed during respiration.

Growth processes, imperceptible outwardly, continue. There is a preparatory period. Without it, active growth in spring and summer is impossible. It is in winter that the active formation of the educational tissue (meristem) takes place, from which new cells and tissues are created, which are so necessary for growth. Can this information answer the question of whether a tree grows in winter, why does it not freeze?

Maybe yes. After all, it is these processes that prepare the tree for growth. Without educational tissue, tree growth is impossible. It is at this time that the primordia of leaves and flowers in the buds (vegetative and flower) are born. This occurs in both deciduous and coniferous trees.

The length of the dormant period

So do trees grow in winter, why do some of them enter the growing season earlier and others later? The duration of dormancy for all trees and shrubs is different and does not occur simultaneously. If you take lilac, honeysuckle and blackcurrant, then they have a dormant period, which begins in October, the shortest. When grown in greenhouse conditions, they behave like evergreens. In these situations, the buds open in November. This suggests that in the process of evolution, these trees and shrubs adapted to cold conditions and learned to shed their leaves.

Until January, this period lasts for birch, hawthorn and poplar. Longer dormancy in coniferous trees, maple, linden and oak. It can be up to six months. As a result, one can doubt whether coniferous trees grow in winter. Preparatory processes they start late, but still they go, which gives the right to give an affirmative answer.

Why do trees not freeze in winter?

How do trees resist the cold? Small plants covered with snow do well. But why don't large trees with bare branches freeze to death? What helps them resist the cold? The fact is that they have a natural antifreeze, which allows you to withstand significant frosts. These are sugars that trees make from starch stored in the summer. Sugars play a special role in the cytoplasm, preventing proteins from clotting (coagulation) during a decrease in temperature. The more starch stored, the more sugars. It is they who give the trees the opportunity not to freeze in winter.

The need for a rest period

It is often asked why we do not see the process of growth itself. But after all, if a tree has not visibly increased, then this does not mean at all that it does not grow. It is in winter that the most important process of future growth, described above, begins. Without it, the spring vegetation of the tree is impossible.

It has been noticed that if the winter is warm, with little snow and short, then the trees do not grow well in spring and summer. This indicates the importance of the cold season for them, which makes it possible to prepare for active development and growth.

If you dig snow in a deciduous forest in February, you can see small sprouts near the trees. In summer, the so-called growth is formed from them. This suggests that trees grow in winter as well. Under the snow, the temperature is about zero, which creates normal conditions for life.

Some people are interested in the question of whether trees grow in winter? The answer is simple and difficult. It is well known from the school curriculum that trees are at rest in winter, but this does not mean that it lasts the entire winter period. All living organisms, including plants, experience periodicity in development. Trees are no exception, they also have certain periods: two main ones (vegetation, dormancy) and two transitional ones.

Vegetation and dormancy

The state of vegetation does not need to be explained. It is during this period, which is the longest, that the laying and development of flower and leaf buds takes place, from which leaves, ovaries, flowers appear, fruits grow and ripen. During the growing season there is a significant increase in the root system. By the time the leaves are formed, it is very important that many small suction roots appear.

In the period of winter dormancy, the trees seem lifeless, but it is worth noting that this is an external manifestation. Their active functioning continues, however, it is not as intense as in summer, a certain amount of nutrients and water enters the plant. So is it true that trees grow in winter too?

When there is a state of rest

Since December, an increase in daylight hours begins, and the vital activity of trees is activated. The preparatory period preceding the growing season begins. That is, the processes of formation of educational tissue begin. All this gives every right to give an affirmative answer to the question of whether trees grow in winter.

What happens at rest

The length of the dormant period

So why do some of them enter the growing season earlier and others later? The duration of dormancy for all trees and shrubs is different and does not occur simultaneously. If you take lilac, honeysuckle and black currant, then they have a dormant period, which begins already in October, the shortest. When grown in greenhouse conditions, they behave like evergreens. In these situations, the buds open in November. This suggests that in the process of evolution, these trees and shrubs adapted to cold conditions and learned to shed their leaves.

Until January, this period lasts for birch, hawthorn and poplar. Longer dormancy in coniferous trees, maple, linden and oak. It can be up to six months. As a result, one can doubt whether coniferous trees grow in winter. Their preparatory processes start late, but they are still going on, which gives them the right to give an affirmative answer.

Why do trees not freeze in winter?

The need for a rest period

People often ask about whether trees grow in winter, why we do not see the growth process itself. But after all, if a tree has not visibly increased, then this does not mean at all that it does not grow. It is in winter that the most important process of future growth, described above, begins. Without it, the spring vegetation of the tree is impossible.

No, unfortunately trees do not grow in winter. In winter, the trees can be said to fall asleep, only in spring their growth begins. This can be understood by observing the birch. As soon as the sap flow begins, the tree comes to life. People collect birch sap, and then the leaves on the tree bloom.

No, they don't grow. The process of photosynthesis (formation organic matter from inorganic with the help of light) is impossible, because in winter there are no green leaves where this process takes place.

It has been proven that trees grow constantly, as long as they live, they grow.

2. Coniferous trees often grow slowly. Therefore, birds need to be fed in winter. These fertilizers will not harm the soils of the Non-Black Earth Region, which are not distinguished by high fertility. However, such top dressing is useful only for those plants that bear fruit well this season. Of no small importance in protecting plants from low temperatures are their adaptive capabilities.

Frost resistance drops in the spring, when sugars begin to be used in vital processes and turn into other compounds. That's why they're so dangerous spring frosts, although the temperature is far from reaching the level of winter frosts, which trees and shrubs endured perfectly. But resistance to frost is explained not only by the accumulation of sugars in tissues. As studies by our well-known plant physiologist, Corresponding Member of the Academy of Sciences I. I. Tumanov and his students showed, the formation of frost resistance is a complex, stepwise process.

Video for children about the life of trees in winter

In the thaw, lichens also come to life, they swell from melt water and grow a little. It is no coincidence that lichens survive where all other plants are unable to live: on the bare stones of the highlands and in the coldest tundra. How different animals hibernate. Lots of snow, lots of bread. Birds often die of starvation in winter.

For us, yes! But the trees are not happy in such ice! Explain that branches are especially fragile at this time. And so they break easily. Therefore, on frosty days, you need to be especially careful with trees and shrubs - they are easy to break.

Watch with your child the behavior of birds, squirrels, feed them (in the warm season, watch insects). On a walk, clearly explain the difference between deciduous and coniferous trees. In birch and aspen, the bark is smooth, but different in color.

Pines, spruces and bare crowns of sleeping deciduous trees - that's all that can now be observed from flora. Well, what! And it's better than nothing. What is the difference between a bush and a tree? The bush has several trunks, as if thick branches stick out of the ground. Find with your child some trees and some shrubs in the yard and in the park. Name them to your child. The roots and the aerial part of the stem grow rapidly, branch strongly and reach large sizes. Under natural conditions, without human intervention, a branched grape bush grows with many vines of various orders, which comes into fruiting late and yields irregularly.

Until January, this period lasts for birch, hawthorn and poplar. Longer dormancy in coniferous trees, maple, linden and oak. It can be up to six months. And the longest - in small-leaved linden, Tatar maple, Siberian spruce, Scotch pine. Wintering lime buds, for example, are unable to germinate for almost half a year. In oak, beech, ash, the buds are in a dormant state until the end of April. And the oak has a sprawling crown, of a different shape - like a tent, a dome, the branches are thick, winding.

Observation 1. Trees and bushes. Trees have one trunk - large, powerful, it starts from the roots near the ground and goes up to the branches. The bark of the trees is also different - stroke it, take a closer look, tell us how you can find out from the bark what kind of tree it is (oak, birch, mountain ash, linden, poplar). Spruce is rough. Ash has cracks. In oak - thick, with deep cracks.

But not all annuals will overwinter as seeds. Some of them have already sprouted. annual plants in autumn they produce seeds and die. And perennials are preparing for winter. They accumulate "food" in the rhizomes for the winter. And hide under a thick layer of fluffy white snow- they winter there. Snow for them is like a fluffy warm carpet that warms the grasses and prevents them from freezing. The older the tree, the thicker the cork layer in it, which is why old, thick trees tolerate cold better than young trees with thin stems and branches.

Do conifers grow in winter

It is at this time that the primordia of leaves and flowers in the buds (vegetative and flower) are born. This occurs in both deciduous and coniferous trees.

Oak, maple, birch and others deciduous trees have beautiful yellow colors leaves and later lose them. Coniferous trees (spruce, pine) go into winter with preserved green needles. Cranberries also hibernate even with berries. And in the spring you can collect overwintered cranberries. They are said to be very sweet.

Birds in winter "- Wintering birds do not fly away from us in warmer climes. Others use their reserves. Most hibernate with green leaves coniferous plants. Black woodpecker. In the very frost, very small and helpless cubs are born to the she-bear.