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 tree bark come from

Such an assertion to the gardener may seem strange. Indeed, in the literature we read the following: “Roots continue their life activity if the temperature in the surface root layer of the soil is positive.” Everything is correct, and gardeners and gardeners of small garden areas, and these are inquisitive, persistent people, often experimentally confirm the above conclusion. So, in our gardening during autumn tillage, we, in addition to organic and mineral fertilizers (potassium, phosphorus), also introduce nitrogen. Horrible! “The erudite” reader will exclaim, “how can this be?” After all, nitrogen fertilizers are applied to the soil only in the spring. Moreover, in the autumn we also scatter wood ash under the trees. It would seem that this makes no sense, because in winter the roots "sleep" and the tree is in biological rest.
Nevertheless, its roots continue their activity in 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 aboveground part grows and develops in the warm season, but the roots behave differently, such is their nature - they continue to grow in the winter. In an apple tree, for example, they can grow even in January, if the temperature around them does not drop below -1 ...- 2 ° C.
Much depends on the moisture and nutrient reserves in the soil, soil solution and water that absorb the roots. 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. It was experimentally established that the roots that appeared in autumn and winter are more stable and longer than spring ones. Few amateur gardeners know this, but this is true. Studies by scientists have shown that the root system of plants absorbs nutrients from the ground, not only in autumn but also in winter, if the soil is not too frozen from above. Yes, it can’t freeze strongly if it is covered with a thick layer of snow (this is the best shelter of the aerial parts of plants from frost). Enough 20-30 cm of snow cover to protect the roots from freezing, and even if we bring this snow hill to a height of 120-150 cm, even in the most severe frost the temperature under it will not drop below -6 ...- 10 ° C , In the soil itself, it still retains positive indicators for a long time. This allows the roots to continue to accumulate nutrients, preparing for spring growth.
So, plants convert mineral nitrogen to organic, accumulating it in the root system. With good tree care, the nitrogen content can double from the beginning of October to January! Whereas in poorly fertilized areas it can grow by only 10%. In this regard, it is very useful to apply nitrate or ammonium sulfate to the soil in the fall and winter. From the foregoing, we make an important practical conclusion: do not be afraid in the fall to feed trees and shrubs with nitrogen fertilizers. These fertilizers will not damage the soils of the Non-Black Earth region, which are not distinguished by high fertility. However, such top dressing is useful only to those plants that bear fruit well this season.
Equally important in protecting plants from low temperatures are their adaptive capabilities. So, in the winter period, the reserves of substances protecting 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 effects of stressful situations.
However, in conditions of extremely low temperatures, many plants die because their intracellular fluid freezes, and the cells undergo destruction. In frost-resistant plant species, this usually does not happen, because they are internally protected by intracellular antifreeze or cryoprotective agents.
I. Krivega
Newspaper "GARDEN" №6, 2010

With the onset of winter, trees go into a state of rest. Metabolism inside the trunk is inhibited, the visible growth of trees is suspended. But the processes of life do not completely stop. In the period of long winter dormancy, mutual transformations of substances occur, albeit with much lower intensity than in summer (Journal of Chemistry and Life, Plants in Winter, V.I. Artamonov, February 1979).

Growth is underway, although outwardly it is almost not manifested. In the cold, the so-called educational tissue is actively developing, from which new cells and tree tissues subsequently arise. In winter, leaf buds begin to lay in deciduous species. Without such processes, the transition of plants to active life with the advent of spring would be impossible. The winter dormant phase is an indispensable condition for the normal growth of trees during the growing season.

The ability of trees to plunge into a state of rest developed during a long evolution and became the most important mechanism for adapting to adverse and harsh external conditions. Similar mechanisms are included in other difficult periods of tree life, including in summer. For example, in severe drought, plants can dump foliage and almost completely stop their growth.

Features of winter dormancy in trees

The signal for a 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, a change in the ratio of substances between the substances that stimulate the processes of metabolism and growth occurs in plants. The tree is gradually preparing to slow down all life processes.

In a state of forced rest, the trees remain until the end of the winter period, gradually preparing for complete awakening. If at the end of February you cut a birch branch in the forest and place it in water in a warm room, after a while the buds will begin to swell, preparing to shoot. But if you perform a similar procedure 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 of 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 rest for four to six months. After wintering, trees slowly but steadily begin to restore life processes, resuming their growth.

Some people wonder if trees grow in winter. Answering it is simple and difficult. It is well known from the school curriculum that trees in winter are at rest, but this does not mean that it lasts all winter. Any living organisms, including plants, experience periodicity in development. Trees are no exception, they also have certain periods: two main ones (vegetation, rest) and two transitional ones.

Vegetation and dormancy

The vegetation state does not need to be explained. It is in this period, which is the longest, that the laying and development of flowering and leafy buds takes place, from which leaves, ovary, flowers emerge, and the fruit grows and ripens. There is a significant increase in the root system. By the time leaves are formed, it is important that many small, absorbent 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 the summer, a certain amount of useful substances and water enter the plant. Is it true that they are also growing?

When rest comes

It is believed that a state of rest occurs in winter. This is not true. It starts very early. To do this, there is a certain signal that nature gives trees - a decrease in the duration 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 discharge of foliage.

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

It is noticed that a tree growing near a lamppost or near a house where the lights burn in the evenings does not dump foliage for a long time. This is a direct confirmation of the dependence of the resting state on the duration of daylight hours.

What happens at rest

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

Growth processes, invisible externally, continue. There is a preparatory period. Without it, active growth in spring and summer is impossible. It is in winter that there is an active activity in the formation of educational tissue (meristem), from it new cells and tissues are created, so necessary for growth. Can this information answer the question of whether the 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 was at this time that the beginnings of the buds of leaves and flowers in the buds (vegetative and floral) occur. This occurs in both deciduous and coniferous trees.

Length of rest period

So do trees grow in winter, why do some of them enter the growing season earlier and others later? The dormancy of all trees and shrubs is different and occurs at the same time. If you take lilac, honeysuckle and blackcurrant, 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 bloom in November. This suggests that in the process of evolution, these trees and shrubs adapted to cold conditions and learned to drop leaves.

Until January, this period lasts for birch, hawthorn and poplar. Longer resting time in conifers, maple, linden and oak. It can reach six months. As a result, one can doubt whether conifers grow in winter. The preparatory processes for them begin late, but still they go, which gives the right to give an affirmative answer.

Why trees do not freeze in winter

How do trees resist cold? Small plants, covered with snow, feel good. But why do not large trees with bare branches freeze out? What helps them resist the cold? The fact is that they have natural antifreeze that can withstand significant frosts. These are sugars that trees produce from starch stored in the summer. Sugars play a special role in the cytoplasm, preventing the proteins from clotting (coagulation) during lowering of temperature. The more starch stored, the more sugars. They give trees the opportunity not to freeze in winter.

The need for a rest period

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

It is noticed that if the winters are warm, not very snowy and short-lived, 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 in February you dig up snow in a deciduous forest, you can see small sprouts near the trees. In summer, the so-called shoots form from them. This suggests that trees grow in winter. Under snow, the temperature is around zero, which creates normal conditions for life.

Vegetation and dormancy

The vegetation state does not need to be explained. It is in this period, which is the longest, that the laying and development of flowering and leafy buds takes place, from which leaves, ovary, flowers emerge, and the fruit grows and ripens. During the growing season there is a significant increase in the root system. By the time leaves are formed, it is important that many small, absorbent roots appear.

When rest comes

Since December, the increase in daylight begins, and the vital activity of trees is activated. The preparatory period begins before the growing season. 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

Length of rest period

So why do some of them enter the growing season earlier and others later? The dormancy of all trees and shrubs is different and occurs at the same time. If you take lilac, honeysuckle and blackcurrant, 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 bloom in November. This suggests that in the process of evolution, these trees and shrubs adapted to cold conditions and learned to drop leaves.

Why trees do 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 if a tree has not grown visibly, then this does not mean at all that it does not grow. It is in winter that the most important process of future growth begins, described above. Without it, spring tree vegetation is impossible.

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

No do not grow. The process of photosynthesis (the formation of organic matter from inorganic by light) is impossible, because in winter there are no green leaves where this process happens.

It is proved that trees grow constantly, while they live - they grow.

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

Frost resistance falls in the spring, when sugars begin to be used in the processes of life, turn into other compounds. Therefore, spring frosts are so dangerous, although the temperature does not reach the level of winter frosts, which the trees and shrubs perfectly endured. But resistance to frost is explained not only by the accumulation of sugar in tissues. As the studies of 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 tree life in winter

In the thaw, lichens also come to life, they swell from meltwater 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. A lot of snow a lot of bread. Often birds die of starvation in winter.

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

Observe the behavior of birds, squirrels, and feed them (observe insects in the warm season). On a walk, clearly explain the difference between deciduous and coniferous trees. Birch and aspen bark is smooth, but different in color.

Pine trees, spruce trees and bare crowns of sleeping deciduous trees - that’s all that can now be observed from the plant world. Well then! And it's better than nothing. And how is a bush different from trees? The bush has several trunks as if thick branches stick out from the ground. Find with your child several trees and several bushes in the yard and in the park. Name them to the child. The roots and the aerial part of the stem grow quickly, branch strongly and reach large sizes. In natural conditions, without human intervention, a branched grape bush grows with many vines of various orders, which later comes into fruition and irregularly produces crops.

Until January, this period lasts for birch, hawthorn and poplar. Longer resting time in conifers, maple, linden and oak. It can reach six months. And the longest - in small-leaved linden, Tatar maple, Siberian spruce, and ordinary pine. Wintering linden buds, for example, are unable to germinate for almost six months. In oak, beech, ash, the kidneys are in a resting state until the end of April. And the oak has a sprawling crown, of another shape - like a tent, a dome, branches are thick, winding.

Observation 1. Trees and bushes. The 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, look carefully, tell how you can find out what tree it is from the bark (oak, birch, mountain ash, linden, poplar). At spruce - rough. Ash - with cracks. Oak is thick, with deep cracks.

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

Do conifers grow in winter

It was at this time that the beginnings of the buds of leaves and flowers in the buds (vegetative and floral) occur. This occurs in both deciduous and coniferous trees.

Oak, maple, birch and other deciduous trees have beautiful yellow leaves, and later lose them. Coniferous trees (spruce, pine) in winter go with preserved green needles. Cranberries also hibernate even with berries. And in the spring you can pick overwintered cranberries. They say they are very sweet.

Birds in winter ”- Wintering birds do not fly away from us to warmer climes. Others use their stocks. Most conifers winter with green leaves. Black woodpecker. In the freezing cold, very small and helpless cubs are born.