Description: War Thunder is a next generation military MMO game dedicated to...
Already in the first days of September, the characteristic signs of the next season are clearly visible on the trees. They are carried by the imminent autumn. Leaf fall for each type of tree occurs at its own time.
Features of leaf fall
Watching the trees, you involuntarily begin to think, and when does the leaf fall of the linden, mountain ash, apple tree and other plants end? Leaf fall is an uneven phenomenon, its duration is estimated at several weeks. Multi-colored foliage is in no hurry to leave the crown. Colorful leaves seem to reluctantly leave the branches one by one.
Abundant fall of foliage occurs at the end of September and the beginning of October (until the first decade expires). Leaves caught by the third and subsequent frosts fall off en masse. Dense leaf fall covers the ground with a motley carpet.
The leaves, flying vertically, gently fall to the ground, covering it with a thick bedding that saves the rhizomes from freezing. Slanting rushing leaves play bright gusty wind, having circled enough, they find a safe haven.
The beginning of leaf fall
The crowns of lindens begin to blaze with autumn colors long before the arrival of the first frost. In the last days of August, single strands are visible among the branches, painted in grayish-yellow tones. The proportion of colored leaves increases daily, the color palette becomes more intense. A noticeable gilding creeps on the crowns of lindens. And after 14-20 days, the foliage begins to burn with gold.
By this time, birches put on an ocher-yellow outfit. Foliage is reddening. Ash crowns shine with pale honey tones. Oak leaves are filled with brown colors. In the lacy crowns of mountain ash, pink leaves shine. And the wild rose bushes flash with a wine-red color scheme.
By the time the leaves of the linden fall, and this happens not earlier than September 23, the crowns of other trees are already actively exposed. The first leaves of birches, aspens, maples and hazel fell off on September 14th. Intense leaf fall in lindens is noted after the first frost piercing the air, which usually happens on September 27th.
First, lindens lose their leaves from large branches located below. Then the foliage crumbles from the middle of the crown. Tops of lindens are exposed last. In elms, ash and hazel, on the contrary, the upper branches are first exposed.
End of leaf fall
By October 7, lindens lose their last leaves. At that moment, when the leaf fall near the linden ends, together with the alder, they did not even think about exposing their dense crowns. Their leaves do not change color, they remain green until the first fluffy snow. Their foliage, seized by a strong frost, instantly turns black. It is difficult for crispy frozen leaves to stay on the branches, they quickly crumble to the ground.
By the time the leaf fall of the linden ends, the elm and bird cherry are completely bare. Their leaf fall ends by September 24th. Aspens are ahead of lindens, their leaf fall comes to an end on October 5th. Birch, maple and hazel are in no hurry to part with foliage. A few leaves are kept on them until October 15.
Natural phenomena during linden leaf fall
The period of leaf fall of lindens is accompanied by the arrival of cold fronts and night frosts. Cumulus clouds displaces a continuous veil and a grayish haze. Flocks of birds flying south appear in the sky. After September 27, the cranes stretch across the sky in a slender shoal in a southerly direction.
And when the leaf fall near the linden ends, the half-naked crowns of other trees blaze with the brightest contrasting colors. Rooks, huddled in friendly flocks, fly away to warmer climes. Snow dust swirls in the air. Falling snowflakes do not yet fall to the ground, do not powder its surface. Puddles twitching thin ice. Skies of dirty grayish shades, devoid of clouds, turn into a gloomy rain film.
Sasha K. (Belogorsk)
In what period does the leaf fall of linden and birch begin and end?
With the onset of September, the trees gradually begin to change the summer emerald green color of the leaves to autumn yellow. A little more time will pass and all the golden foliage will rush to the ground. Watching nature, people often ask themselves the question - when does the leaf fall end for birch, linden, maple and other favorite yellowing trees? Let's try to answer this question.
When the leaves turn yellow
Foliage begins to change color long before the first frost. As a rule, this happens at the end of August, when the day has already noticeably decreased and it has become a little colder, and lasts for 14-20 days. At first, only single gray-yellow patches are visible on the branches, but day by day there are more and more of them.
By mid-September, birch leaves become ocher-gold and gradually begin to fall off. Maple branches are no less beautiful at this time. The crowns of the tree are covered with foliage of yellow, brick red, red and even purple hues. The foliage of the linden, which is only half yellowed, stands out noticeably.
The beginning of leaf fall
For many trees, leaf fall is uneven, that is, it happens in different time. For example, after the first severe frost, leaf fall begins in linden and maples. By this time, the birch had already dropped most of the leaves. Her leaf fall begins in the first decade of September and lasts 15-20 days.
Important! The beginning of leaf fall depends on the weather. Dry sunny weather and windless days delay the golden decoration of trees.
Leaf fall is especially abundant after the third frost. The leaves fall to the ground very densely, forming a thick bedding on the ground. Birch drops about 30 kg of leaves in autumn. In an adult linden and maple, this amount reaches 40-50 kg.
End of leaf fall
The end of leaf fall, as a rule, is accompanied by a significant cooling, deterioration weather conditions, frequent rain and strong gusts of wind. By October 7-10, lindens and birches lose their last yellow leaves. Maples are exposed much later, only by October 20. Single leaves can be kept on the branches until mid-November, reminding passers-by of the past golden season.
Observations of nature during leaf fall
The period of active leaf fall is accompanied by a significant cooling and the arrival of night frosts. Summer white clouds are replaced by a solid gray veil. It is often foggy in the morning. The first flocks of migratory birds fly into the sky.
The end of leaf fall in lindens and maples is accompanied by gloomy rainy weather, frost on the still green grass and thin ice on the puddles. Rooks gather in flocks and fly south. Gradually the earth cools down and nature falls asleep.
Autumn leaf fall: video
Mountain ash, viburnum, thickets of hawthorn blaze with flames. And some apple trees stand like bonfires: these are the latest, the last apples in the garden - Welsey, Pepin saffron, Lobo, Spartan, Rossoshansky striped apples filled with raspberry-red fire. The trees were bent under the weight of the harvest. The weather is still warm. She had kept the leaves active for the last few weeks before a bitter October wind and cold rain they cover the damp earth.
In all the time of his short life, not one of them slept an hour, assimilating Sun rays, carbon dioxide, mineral salts, producing nutrients and sending them to the still ripening shoots, fruits, spears, twigs, flower buds, roots - to where they are still required to complete growth, to be deposited in reserve.
The above-ground part of the tree at this time is more and more deeply covered by a state of rest. By introducing humus, compost, manure, even just by mulching the soil, you can significantly extend their active work, since these measures help to keep the heat in the root-inhabited soil layer longer and thereby increase the accumulation of nutrients.
Little of, fruit trees and shrubs can be specially prepared for the winter. In order for them to meet it prepared, it is important to cultivate the soil in the aisles and on the near-stem circles (strips) in a timely manner, apply fertilizers, carry out water-charging irrigation, taking into account the future, and the fact that autumn drought is not uncommon even in the forest belt.
A significant role is played by the work of those leaves that remain on trees and bushes until late autumn and provide all living tissues both in the aerial part and in the roots with plastic substances that are deposited in reserve and increase the resistance of trees and shrubs to all sorts of adversities. And it’s very good when they stay longer on the tree, although it happens that this serves as an indicator of the incomplete ripening of shoots and buds: the timing of leaf fall does not coincide over the years and depends more on the course of the weather than on our efforts, but still high agricultural technology contributes to more long activity of leaves.
For a long time and in different areas of the country, it has been noticed that in early varieties, preparation for winter dormancy is completed faster, they also move on to shedding leaves earlier. Care also affects them.
The leaf, ready to leave the branch, acquires a color characteristic of the variety, a separating layer appears at the base of its petiole. This place will then quickly grow impenetrable cork layer. Lentils on shoots also hide behind similar "shutters".
The buds, laid in the axils of the leaves on the shoots in the middle of summer, stop growing long before the leaf fall. Inhibitors released by the apical bud of the shoot and leaves slow it down more and more and, finally, stop it completely. All varieties horticultural crops differ significantly in the need for cold in order to resume vegetation. Usually it is expressed as the sum of hours of autumn and winter temperatures not exceeding 7 degrees.
However, complete, or, as they say, absolute, organic peace still cannot be considered. Some researchers have observed changes in growth points and generative buds even in the middle of the dormant period. What are the most characteristic signs for this? In the cells of the growth cones and adjacent tissues, the viscosity of the protoplasm increases greatly, it often moves away from the cell walls, and the connection between individual protoplasts becomes very limited. Lipoids accumulate on their surface, sharply weakening the ability of the cytoplasm to swell, and the nucleus loses its usual round shape and is not clearly distinguished from the protoplasm. By the end of the dormant period, they dissolve, and the connection between the protoplasts is restored, their vital functions and capabilities expand. And already in late December - early January, the buds acquire the ability to awaken, grow, bloom leaves and flowers. And by transferring the branch of the apple tree into the room, putting it in a vase of water, you can be sure of this in a few days - it will bloom.
Under the influence of cold, enzymes also begin to act differently in tissues and growth points: they transfer reserve substances from insoluble forms to soluble ones, for example, starch into sugar, which is why, by the beginning of winter, a lot of sugars and fats accumulate in the cells, protecting living tissue from the harmful effects of frost - their winter hardiness increases markedly. All life processes in them are aimed at increasing the resistance of tissues against adverse conditions.
Flower buds usually enter winter already with the rudiments of sepals, petals, stamens, and also pistils. This completes the first, summer-autumn stage of their development, although the change in their requirements for nutritional conditions, for the concentration of cell sap, as studies have shown, occurs much earlier, as early as late summer - early autumn. And the signs of change here are not external morphological changes in the cones of growth - they are not difficult to establish by looking at the longitudinal section of the kidney through a strong magnifying glass - but internal qualitative changes in the cells. Under favorable conditions, they pass 20-25 days before the appearance visible changes in the cone of growth and the beginning of the formation of flower organs in it.
The further development of flower buds proceeds normally only on the basis of qualitative changes characteristic of the second stage of their development, which requires a good saturation of the cells with water. But since they usually have such a condition only in spring, the flowers begin to actively develop only after the spring awakening of the buds. In autumn, their growth is more and more inhibited by the relatively high concentration of cell sap in the growth cones, and then by increasingly severe cold. Therefore, instead of 25-30 days (under favorable conditions), this period lasts five to six months or longer.
It has long been noted that for the normal development of flower buds, for example, in plums, at least two months of relative “cold” are needed. Further studies showed that some kind of qualitative "jump", a turning point in the formation of flowers, for which low temperature, No. That is, in itself, as an obligatory factor in development, it is not required for them, but if the kidneys have already entered a period of rest, then they need exposure to cold to restore normal vital activity.
But the roots of trees and shrubs and late autumn almost everywhere they continue to work very actively, especially if the near-trunk circles and the aisles of the garden were well mulched: the cold then penetrates slowly into the depths of the soil. At 5-10 degrees of heat, they feel good, absorb and accumulate nutrients in their tissues, since there is almost always enough moisture in the soil at this time. It is good to add at least a small amount of wood ash, mineral fertilizers, humus to the trunk circles, if this has not been done before.
To disinfect the garden, it is useful to spray them with a 4% solution of urea (400 grams per 10 liters of water). It is better to rake the fallen leaves without such treatment, and not only under apple trees, pears, plums, but also under birches, lindens, willows, mountain ash growing near the house, and sprinkle the soil with a stronger 7% urea solution. First of all, such processing should be carried out under dwarf apple trees - they are more vulnerable than others, as well as in the aisles of strawberries and strawberries, under young and newly planted trees, and the soil should be harrowed.
Long before cold. cloudy, changeable late fall in middle lane. Having laid bare the garden, she only in some places on the tops of the shoots of the most heat-loving late varieties still left browned leaves that did not have time to fully bloom. The garden brightened and emptied.
The frost resistance of plants is a changing property. It develops throughout the growing season, but especially strongly - at the end of summer and autumn. Its first stage is the weakening and cessation of growth processes, the transition to a state of rest. The second is the beginning of hardening.
By the time of leaf fall, the tissues and organs of plants are filled with starch, which hydrolyzes (splits) when the temperature drops. The resulting sugar, as well as fats, are consumed in winter. are changing physical properties protoplasm, and growth is completely inhibited. After such preparation, the slow increase in frost does not threaten the plant.
So, winter hardiness is determined not only by the properties of growing tissues, but also by the course of metabolism, which ensures the processes of vegetation and the transition of the plant to a new physiological state, which gives the tissues the ability to endure low temperatures.
AT last years in the middle zone of steel, it is widely grown varieties of a high-intensity type, very whimsical and demanding on the conditions of agricultural technology. Some of them are imported from places with a milder climate or from abroad. Their frost resistance, as tests have shown, is noticeably lower than that of old Russian varieties. And this cannot be ignored.
Some varieties, painfully enduring severe frosts, often freeze slightly and suffer in relatively mild winters, but with sharp drops in temperature after thaws. That's why essential feature varieties can be considered its ability to maintain high frost resistance after thaws. Studies have shown that the bark and cambium of trees of old Central Russian varieties are more resistant to frost after thaws than those of foreign and new breeding varieties. However, it should be noted that the varieties Wellsey, Mayak, Vityaz, Voskhod turned out to be more stable than others. Trees of the varieties Lobo, Vityaz and Mantet are not inferior to Pepin saffron in terms of frost resistance, but their regenerative ability is different: in Lobo it is good, in Vityaz and Mantet it is weak.
But no matter how successful the hardening of horticultural crops is, even in the fall, when the rainy season ends, in the second half of November it is very useful to inspect all the trees and bushes, establish damaged places, clean them of dirt and litter, cover them with garden pitch, put them under the branches "winter" chatals in order to protect them from breaking after heavy snowfalls. It is also important to remove from the trellis in a timely manner, lay on the ground and shelter from the cold climbing plants - actinidia, lemongrass, grapes, blackberries, climbing and other roses. Until the raspberry shoots are frozen and brittle, they are carefully bent along the rows to the ground and fixed in such a position that by the time severe frosts they were completely covered in snow. With the help of slats and pegs, it is advisable to press and “spread” bushes of gooseberries, golden currants, mock oranges and other shrubs that do not have a sufficiently high winter hardiness in the middle lane below the ground. After the first snowfalls, it is useful to cover them with snow in the same way as young trees of apple trees, pears, cherries, plums. And in the conditions of the Urals and Siberia, all Stlans require shelter with snow, which is called "with a head." In the snowy, air-filled "openwork" mass, the plant does not experience sharp temperature fluctuations that reduce its frost resistance.
In late autumn and early winter, the ground, where there is no snow cover or it is very thin, can freeze strongly and deeply, which leads to damage to the root system of trees. To prevent this, the trunk circles are insulated with mulch, and after the first snowfall they are covered with snow.
Birches are deciduous plants, every year they shed their leaves in order to acquire fresh green “clothes” again in the spring. When does birch leaf fall end? This is often asked by students. Our material will help you understand this and learn a lot interesting facts about this seasonal event.
What is leaf fall?
The term, so familiar to everyone, refers to the biological process during which the leaves of trees, which have lost chlorophyll, are separated from the stems and fall to the ground. This process is characterized by the following features:
- In autumn, the trees take on a variety of colorful colors, from yellow and orange to crimson and crimson red. This happens because before the leaves fall, chlorophyll, the pigment that gives them green color.
- The leaves acquire the ability to easily separate from the branch even with a slight gust of wind due to the formation of a special separating layer that breaks the connection between the leaf and its stem.
- Due to this seasonal phenomenon, the trees are freed from those harmful substances that have accumulated in the leaves during the season of active growth.
- With the help of leaf fall, plants are protected from excessive loss of moisture, which is extracted from the soil in harsh weather. winter time becomes very difficult.
We have considered the main signs of the most important seasonal change in the life of trees. Now let's get acquainted with when the leaf fall near the birch ends, and also when it begins.
Birch
Early autumn is characterized by still warm weather conditions, the thermometer often has a positive value, however, precipitation in the form of drizzle and hoarfrost can fall. The trees begin to turn yellow, playing in the rays of the already dim sun with stunningly beautiful colors. In the first week of September, the thin-stemmed tree begins to lose its foliage.
The average duration of leaf fall depends on weather conditions and can range from 15 to 20 days. The answer to the question of in what month the birch leaf fall ended can be given as follows: September ( last days this month) or October (its first half).
Process features
Birch is one of the first trees to lose foliage, along with aspens, maples, lindens. Considering when the birch leaf fall ends, it should be noted that by the end of October these beautiful trees standing completely naked. The fall of the leaves of the plant begins on September 15, completion - by about October 5, but it is impossible to name a more exact date - it all depends on natural conditions each specific year. The main activity of the process begins after the first frosts, which, as a rule, fall on the last days of September (from about the 28th).
Folk omens
We examined when the leaf fall near the birch ends. Why do people need this knowledge? First of all, observing nature is interesting in itself. However, there are also several folk signs, which were used by our distant ancestors to predict the weather. Some of them are interesting in their own way:
- If the leaves fall from birch and oak simultaneously and evenly, it is worth waiting for a mild winter.
- harsh winter expected if oaks and birches become bare at different times.
- The leaves turned yellow, but did not fall off by the time - there will be frosts.
- The leaves on the white-stemmed tree did not fall in the first week of October - the snow will fall late this year.
- The leaf fall is “according to the scenario”, the tree sheds its foliage in time - we should expect a long thaw at the end of January.
Unfortunately, it is impossible to accurately answer the question of what date the leaf fall of birches ends, however, everyone can determine the approximate time frame: the process of leaf fall of a traditional Russian tree ends by the end of September or the beginning (less often - the second half) October.
Katerina, city of Voronezh
Tell me, when does the period of leaf fall end at the apple tree, as well as mountain ash?
Leaf fall is a seasonal phenomenon in the life of trees and shrubs, which is observed from early autumn. Getting rid of leaves before the onset of winter cold, trees regulate the process of moisture consumption, significantly reducing its need. The process of leaf fall different trees starts and ends at different times. This largely depends on weather conditions and the area where green spaces grow, as well as the types of trees and their age.
It is difficult to unequivocally answer the question when the time of leaf fall ends. It is noticed that first poplar leaves are lost, then oaks and mountain ash. Apple trees are slowly shedding their leaves, and even in winter on some trees, single leaves continue to flutter in the cold wind.
Trees at the time of leaf fall
Dropping leaves from trees serves another purpose - the crown under the snow cover has a significant weight. The branches of trees, especially young ones, are not able to withstand such a load. Fallen leaves can reduce the load on the skeletal branches of the tree, protecting the crown from damage.
Thanks to the process of photosynthesis, a large amount of harmful substances accumulate in the leaves by the beginning of autumn, which, with the onset of leaf fall, are removed along with fallen leaves.
The end of leaf fall in different tree species
Poplar
During the period of leaf fall, adult poplar trees lose a third of their leaves in the period from September 15 to 20, in the first ten days of October, up to 10% of foliage remains in the poplar crown. Completely lose poplar leaves by mid-October. Young poplars remain green longer than old trees, they turn yellow later and shed their leaves.
Oak
Oak leaves fall off in the first half of September, after about 30 days the trees completely lose their leaves. With early frosts, the timing of the end of leaf fall on oaks is reduced - trees quickly lose leaves at sub-zero temperatures. oak leaves immediately acquire a brown color, along with the leaves, ripe acorns fall from the tree.
Mountain ash in autumn: video
